ZSE Aviation Forecast Discussions

883 FXUS66 KSEW 230300 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 800 PM PDT Wed Jul 22 2026 .UPDATE... Scattered showers and thunderstorms making their way northeastward over western Washington this evening. Activity has had some difficulty holding together as it moves into the area with the most impressive cells winnowing away as they enter the CWA. However, still getting strikes on satellite and while thunder risk may diminish further tonight and overnight, cannot rule out isolated thunderstorms into Thursday. Otherwise, inherited forecast remains on track. 18 && .SYNOPSIS... Moisture working its way up into the area from the south will result in chances for showers and isolated thunderstorms into Thursday. An upper level trough offshore will then push inland over the weekend, bringing cooler temperatures to the area and additional chances of showers. Troughing will persist through early next week, allowing for temperatures to trend just below to near normal. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/... It`s hot out there- latest observations show temperatures trending in the mid 80s to mid 90s across much of the interior of western Washington this afternoon. The thermal trough that was situated along the coast has started to make its way inland as winds have already switched back to onshore this afternoon. Temperatures along the Pacific coast are currently trending in the mid 50s to mid 60s as a result and shower activity and cloud cover have started to stream up into the area. Chances of showers and isolated thunderstorm activity will increase this evening along the coast, areas south of the Sound, and the southern Cascades as moisture from a trough offshore continues to stream northward into the area. With dry conditions in the low levels, any rainfall associated with the shower activity that initially moves into the area may have a hard time making it all the way to the ground. Shower and isolated thunderstorm activity will then increase in coverage and expand area wide tonight into the overnight period as moisture continues to stream into the region and winds transition to southwesterly. Critical fire weather conditions are expected to develop along the coast, south interior, and southern Cascades tonight into Thursday as lightning from isolated thunderstorm activity could cause additional ignitions. Thursday morning low temperatures will remain mild and will generally be in the upper 50s to mid 60s across the area. Shower and thunderstorm chances will continue through the day on Thursday, but will gradually become more confined to the Cascades. The pattern change will allow for afternoon high temperatures to cool 10 to 15 degrees in comparison to today, with highs expected to top out in the upper 70s to low 80s across the area. Drier conditions and a slight warm up are expected again by Friday with an upper level trough remaining offshore. Onshore flow will allow for the marine stratus to push into the Sound by early Friday morning and will bring cooler morning lows to the area- mostly in the 50s to low 60s. The layer will retreat back to the coast by the afternoon, allowing for highs across the interior to warm back into the mid 80s. Highs along the coast will remain cooler under the marine stratus- and only look to top out in the mid 60s to low 70s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... Guidance remains in good agreement that the upper level trough offshore will move across the area over the weekend, which will bring cooler temperatures and additional chances of showers to western Washington. The greatest chances of precipitation will be along the coast and northern interior areas on Sunday as a shortwave from a trough off the coast of British Columbia moves into the area. Afternoon high temperatures will be below to near normal across the area as a result and are expected to be in the upper 60s to mid 70s across the interior and in the 60s along the coast. Upper level troughing then looks to remain the dominant influence across the region heading into early next week. This will help promote continued onshore flow across the area and high temperatures in the 70s through Wednesday. && .AVIATION... High pressure with a ridge will move to the north as a shortwave trough to the south with an associated upper low will move north tonight into Thursday, with increasing flow from the south aloft. Main concern this evening remains thunder as activity tracks up along the I-5 corridor this evening. Coverage continues to remain in clusters/pockets of convection, with movement to the north around 20- 30 kt. The main hazards remain lightning with gusty winds, although precipitation output has been limited overall. Activity will move to the northeast overnight into the Cascades, with thunder chances Thursday remaining primarily in the Olympics/northwest coast. Ceilings will also lower tonight/Thursday morning, with a 50-60% chance of MVFR for most interior terminals Thursday morning (12Z- 21Z), with higher chances of IFR ceilings/visibilities along the coast. Northwest winds 8-12 kt will switch to the southwest tonight into Thursday 5-10 kt. KSEA...VFR skies through the evening. Convection to arrive at the terminal 03Z, and linger through at least 06Z (though a couple ensemble members have convection lingering an hour or two after as storms to the southwest shift to the northeast). After the thunder moves out, there is a 50-60% chance of MVFR ceilings developing from 12Z to as late as 21Z. Thunder potential for Thursday remains less than 10%. West-northwest winds at 10 kt will switch to the southwest as the convection moves through. HPR && .MARINE...The thermal trough will continue to shift inland, ushering stronger onshore flow back into the region. Expect westerly winds to increase to 25 kt through the central and eastern Strait of Juan de Fuca tonight. Given higher confidence in increasing southerly winds around Bellingham Bay and also through the southern half of Puget Sound, have also issued small craft advisories for the two additional zones for tonight. With onshore flow containing into the weekend, expect to see additional SCA strength winds through the Strait later this week. Seas over the coastal waters remain generally around 5 to 6 ft, but may build further on Saturday (especially over the southern coastal zones) as a result of stronger southerly winds with a persistent fetch through the inner coastal waters. Cullen && .FIRE WEATHER... Elevated fire weather concerns continue today through Thursday resulting from multiple causes. Today is seeing hot and dry conditions. Minimum relative humidities will fall as low as 20% to 30% again later this afternoon, with the drier locations across the southern Puget Sound and portions of the Cascades and Olympics. There is a chance of thunderstorms coming in from the south late Wednesday night through Thursday with the arrival of the remnants of tropical storm Elida, which, given the warm and dry conditions, could cause additional ignitions from lightning. Rainfall from these storms will mainly be light. A Red Flag Warning was issued for the southern Cascades, South Sound, and Olympic Peninsula areas tonight through Thursday night. Increasing onshore flow beginning later Thursday will bring a wind shift with breezy southwest winds. This will also produce cooler temperatures and better overnight RH recoveries through the weekend into the first part of next week easing fire weather concerns. FELTON/JBB && .SEW WATCHES/WARNINGS/ADVISORIES... WA...Red Flag Warning until 10 PM PDT Thursday for Black Hills and Southwest Interior Lowlands-Central Coastal Lowlands-East Portion of the Olympic Mountains-North Coastal Lowlands- North and Central Coastal Strip-West Portion of the Olympic Mountains-West Slopes of the Central Cascades Generally above 1500 Feet. Heat Advisory until 11 PM PDT this evening for City of Seattle- Downtown Everett / Marysville Area-Eastern Kitsap County- Eastern Strait of Juan de Fuca-Eastside-Foothills and Valleys of Central King County-Foothills and Valleys of Pierce and Southern King Counties-Foothills and Valleys of Snohomish and Northern King Counties-Foothills and Valleys of Thurston and Lewis Counties-Foothills and Valleys of the North Cascades-Foothills of the Western and Southern Olympic Peninsula-Lake Crescent Area Including US 101-Lowlands of Lewis and Southern Thurston Counties-Lowlands of Pierce and Southern King Counties- Lowlands of Western Skagit and Northwestern Snohomish Counties-Lowlands of Western Whatcom County-Middle Chehalis River Valley-Northern Hood Canal-Olympia and Southern Puget Sound-Port Townsend Area-Shoreline / Lynnwood / South Everett Area-Southern Hood Canal. PZ...Small Craft Advisory from 8 PM this evening to 5 AM PDT Thursday for Central U.S. Waters Strait Of Juan De Fuca- East Entrance U.S. Waters Strait Of Juan De Fuca. Small Craft Advisory from midnight tonight to 9 AM PDT Thursday for Northern Inland Waters Including The San Juan Islands. Small Craft Advisory until 9 AM PDT Thursday for Puget Sound and Hood Canal. && $$

625 FXUS66 KPQR 230114 AAB AFDPQR Area Forecast Discussion...UPDATED National Weather Service Portland OR 614 PM PDT Wed Jul 22 2026 .UPDATE...Due to cloud cover and showers moving in, daytime heating has come to an end and the risk for elevated heat has ended. Temperatures greater than 90 degrees are no longer expected. Thunderstorms continue to move through the region though so lightning and heavy rain remains a risk. && .SYNOPSIS... Showers and storm chances continue through the evening and into the overnight hours. Frequent lightning and gusty winds are possible with any storm that develops. Temperatures Thursday and Friday will remain warm but not as warm as the previous few days. A cooler and drier trend expected this weekend with temperatures closer to normal. && .SHORT TERM...Now through Thursday...Hot conditions and thunderstorms continue to be the two main threats for today. Temperatures range from the mid 90s around the Portland metro and northern lowland locations while temperatures in the upper 70s to mid 80s are common across the Willamette Valley where cloud cover and precipitation have been more prevalent. Dew points across the area are in the upper 50s to mid 60s which is contributing to the unpleasant, muggy conditions. A Heat Advisory remains in effect until 11 PM for the Portland/Vancouver metro, Columbia River Gorge, northern Willamette Valley, and the Lower Columbia and Cowlitz Valleys into the southwest Washington Foothills. Luckily, today is the last of the temperatures in the 90s, at least for the near future. An upper level closed low remains offshore over the far northeast Pacific and is slowly drifting northwest. This is supporting south to southeast flow in the midlevels which is increasing monsoonal moisture across the area. Hi-res models depict an environment conducive to elevated convection with little surface CAPE but MUCAPE of 500-1000 j/kg west of the Cascades and slightly higher up to 1500 j/kg across the higher terrain. This indicates that the CAPE is elevated and will generally need a forcing mechanism that`s not surface heating for convective initiation. In this scenario, south to southeast flow over the area will produce orographic lift over the higher terrain. PWAT values over the area range from 1.0-1.5 inches but model soundings indicate dry air at the low levels. Given these two variable are at odds, there is both potential for decent local rainfall but also a chance for dry convection. SPC has also added a marginal risk for severe thunderstorms over the central ORegon Cascades for damaging wind potential. DCAPE values over the area are around 700-900 j/kg with an inverted-V sounding which indicated wind potential. Showers and storms will be possible through the evening, decreasing overnight from south to north. The areas including the Portland metro northward hang onto a low (10- 15%) chance into Thursday morning. Conditions trend cooler and less active on Thursday as the upper level ridge weakens a bit. Highs will still be toasty on Thursday with mid to upper 80s expected across the interior lowlands and 60s along the coast. Precipitation chances decrease as available moisture decreases though convection could graze right along the Cascade crest in Lane and Linn counties during the afternoon.-19 .LONG TERM...Thursday Night through Wednesday...Temperatures on Friday are expected to be similar to Thursday as the upper level pattern remains largely unchanged. Heading into the weekend, a pattern change is expected with a trough dropping south from the Gulf of Alaska on Saturday. This will allow onshore flow to re- establish itself and bring a more noticeable cooling trend late this week, along with a return to more marine influence and night/morning cloud cover. This will also support a trend toward more normal temperatures in the upper 70s to low 80s inland along with overnight lows in the 50s. There is no notable precipitation signal outside of low potential for light showers along the coast on Saturday. -19 && .AVIATION...Through 18Z Thursday...Showers and isolated thunderstorms have developed across central and northern Oregon and will track northward through the afternoon and evening hours. Chances will decrease by 00-03z Thu south of KSLE then by 09-12z Thu south of KPDX. All shower and thunderstorm activity should end by 18z Thu. Confidence in the occurrence of thunder is too low at any one terminal to include in TAFs at this time, but heavy showers may briefly result in MVFR/IFR vis if they pass over a terminal. Showers may also produce gusty or erratic winds nearby. Winds have shifted westerly. Along the coast, expect winds up to 10-15 kts with gusts up to 20-25 kts. Winds inland increase to 8-10 kts after 23z Wed, decreasing around 06z Thu. Outside of showers, VFR conditions continue at most terminals with some haze from wildfire smoke. The exception is KONP where there is a 60-75% chance of marine stratus continuing IFR/LIFR conditions through the TAF period. Stratus is forecast to return to the general coast by 00-03z Thu with a 50-75% chance of IFR/LIFR conditions continuing through the TAF period. The west winds will allow for an inland push of marine air, producing a 50-70% chance of MVFR ceilings developing along the Columbia River south into the Portland metro area and around KEUG between 11-15z Thu. There`s a 25-40% chance elsewhere in the Willamette Valley. Afternoon temperatures are forecast to approach 100 degrees at many inland terminals this afternoon; be aware of high density altitude which may reduce aircraft performance. KPDX AND APPROACHES...Chances for showers or an isolated thunderstorm begin around 21z, increasing after 00z Thu. The most likely terminal impacts are frequent lightning, gusty/erratic winds, and locally heavy downpours which may briefly restrict vis to IFR/MVFR levels. Otherwise, VFR conditions persist with hazy conditions from smoke. There`s a 50-70% chance of MVFR ceilings in marine stratus developing after 11z Thu. West winds around 8-10 kts, decreasing by 04-06z Thu. -03 && .MARINE...North to northwest winds over the coastal waters are shifting to south to southwesterly winds this afternoon as weak low pressure remains over the waters. Winds will remain light less than 10-15 kts. Seas will be 3-6 ft at 8-9 seconds. These conditions will continue through the weekend. Showers and thunderstorms continue across the central and northern waters into the overnight hours. Showers and thunderstorms could redevelop Thursday morning. There could be frequent lightning and gusty and erratic winds with any thunderstorm that forms. -03 CLIMATE... Daily record high minimum temperatures for July 22 Astoria 62 (2007) Vancouver, WA 74 (2006) Portland Int`l 74 (2006) Hillsboro 73 (2006) McMinnville 73 (2006) Salem 74 (2006) Eugene 71 (2006) Daily record high maximum temperatures for July 22 Astoria 88 (1891) Vancouver, WA 98 (1928) Portland Int`l 98 (1978, 2004) Hillsboro103 (1938) McMinnville102 (1928) Salem102 (1928, 1978) Eugene101 (2006) && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...None. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

770 FXUS66 KMFR 222321 AFDMFR Area Forecast Discussion National Weather Service Medford OR 421 PM PDT Wed Jul 22 2026 ...New Aviation Section... .AVIATION (00Z TAFs)... Not expecting too much relief along and near the coast today/tonight, so expecting MVFR/IFR conditions to persist for KOTH overnight and through tomorrow. The marine push may come far enough inland to impact KRBG, and confidence was high enough (50%) to include MVFR ceilings overnight through Thursday morning. Otherwise, expecting VFR conditions for both KMFR and KLMT through this cycle, with typical diurnal breezes (enhanced at times) for all terminals. There is a caveat here; we will need to monitor thunderstorm potential (10-15%) near KMFR through ~8pm, but at this time confidence was not enough to include a mention. -Guerrero && .PREV DISCUSSION... /Issued 114 PM PDT Wed Jul 22 2026/ KEY MESSAGES... * Today will be last day of the humid pattern with moist, southerly monsoonal flow and isolated to scattered thunderstorms. Highest risk of scattered thunderstorms today will be from the Cascade foothills in eastern Douglas County across the Cascades, into northern Klamath and Lake counties. Some storms will be strong with gusty winds and possible hail. * Today will be the hottest day of the next several days with highs generally 5 to 10 degrees above normal (mid 80s to mid 90s on the east side and lower 90s to 104 for west side valleys). Near or slightly below normal temperatures at the coast will reach the 60s. * A dry pattern takes hold Thursday into the weekend. An increase in afternoon/evening southwest to west winds is likely, especially east of the Cascades and in NE California where strong winds overlap with very low humidity resulting in critical fire weather conditions Friday and Saturday. DISCUSSION...The area has been wedged between strong upper ridging over the nation`s midsection and low pressure off the West Coast for the last several days, which has brought a plume of very moist, monsoonal moisture into the area. With dewpoints expected to be in the upper 50s to even mid 60s west of the Cascades, it`ll be another humid day with high temperatures again in the 90s and even lower 100s today. In this type of pattern, we usually expect daily outbreaks of thunderstorms. But, this has been muted so far with just isolated activity, mainly due to a lack of forcing and high cloud cover ultimately reducing instability. This will change somewhat today as instability increases across the area and with the low offshore moving northward (along with the remnants of Elida), forcing for ascent should be enhanced near the Cascades in diffluent flow aloft. It will be a race though, so to speak, since models are showing drier air aloft arriving from the south and west today and tonight. The focus for convection this afternoon/evening will be from the Cascade foothills of eastern Douglas County across the Cascades to northern Klamath and Lake counties. Convection allowing models show this area stands a good chance at getting some cells with frequent lightning. They`ll move quickly, around 20-25 mph to the NNE, and with a very dry landscape, this presents a critical fire weather risk, so we have a Red Flag Warning out for that. Storms that do develop could also have strong outflow wind gusts (inverted-v soundings indicate potential near or just sub-severe gusts), hail and brief heavy rainfall. The Storm Prediction Center (SPC) does have portions of our region in a Marginal Risk for severe weather today, meaning there`s a 2%-5% chance for any storm to become severe within 25 miles of any location within the designated area. The highlighted area is mainly from Crater Lake northward along the Cascades and eastward across northern Klamath/Lake counties. While we can`t rule out isolated activity farther south and west, again, the limiting factor will be the drier air moving in aloft. Expect some breezy winds to develop just about everywhere this afternoon/evening. Once we get rid of the convection this evening, that will be it for a while. A re-orientation of the flow aloft to the southwest will bring in a much drier pattern. Models are showing a strong mid-level 500 mb jet of 45-55 kt developing Fri/Sat. This is going to cause breezy to windy conditions area wide, strongest east of the Cascades and in NE California. At the same time, massive drying will bring dewpoints way down resulting in very low humidity, in some cases, down below 10% over Modoc/Lake counties. There is high confidence in this pattern of overlapping strong, gusty winds and low relative humidity, and a Fire Weather Watch is in place for both Fri/Sat pm/eve east of the Cascades and in NE California. These conditions could persist into Sunday, but confidence was not high enough to include Sunday in the watch at this time. Temperatures, meanwhile, should moderate a bit Thursday and Friday, cooling by about 5 to 10 degrees west of the Cascades. Temperatures will even return to near to just below seasonal normals by the end of the weekend and into early next week. Monsoonal moisture should remain well to the south and east of our area into next week due to persistent southwest flow aloft, which is pretty typical for late July. AVIATION...22/18Z TAFs...Mostly VFR is present across northern California and southern Oregon early this morning. Marine stratus has burned back from most of the coast, but remains present in the offshore waters. We expect onshore flow to commence as the day goes on, so it is possible that a surge of low stratus could result in IFR there this afternoon. A stronger marine push tonight will result in IFR conditions along the coast and into the Umpqua Basin overnight tonight. Thunderstorms are expected this afternoon, especially over eastern Douglas County as well as Lake and northern Klamath counties. Activity may also develop in Jackson, and southern Klamath, and western Siskiyou counties. These storms may be strong enough to develop small hail, lightning, locally heavy rain, and gusty, erratic winds. While the most aggressive activity is currently expected to mostly stay away from area terminals, notes of vicinity activity have been included at Medford to communicate the possible development of thunderstorm activity. -Spilde/BPN MARINE...Updated 100 PM PDT Wednesday, July 22, 2026...As tropical remains move north through the southern Oregon coastal waters tonight into early Thursday morning, there will be a brief period of stronger south winds and steep seas, mainly in waters beyond 10 nm from shore. Otherwise, mixed seas with fresh short period northwest swell and low longer period south swell are expected through Friday. South winds switch back to northerly this weekend, but wind wave dominated seas probably hold off until early next week. -Spilde/BPN FIRE WEATHER...Updated 100 PM PDT Wednesday, July 22, 2026... Today, there is a greater concern for increased afternoon and evening thunderstorm coverage (at least in northern parts of the area) due to better instability expected and the potential for better forcing as the remnants of Elida push northward just offshore resulting in diffluent flow aloft. We think the greatest activity in terms of coverage will occur along the western slopes of the Cascades (eastern FWZs 622/617) east across the Cascades (FWZ623), and then also east of the Cascades in the typical arc from Crater Lake, across Winter Rim, and down to the Warners (FWZs 624/625). Isolated storms are also possible elsewhere across the area, including in northern California and across the valleys west of the Cascades, though a surge of drier air aloft does appear to be pushing into NorCal later in the afternoon/evening (this should keep best activity confined to areas north of the OR/CA border). Storms that do develop should be moving at a pretty good clip - in the 20-30 mph range, so while they are likely to be wetter storms with higher PWs, the faster storm motions still raises the risk of lightning-induced fire ignitions and a Red Flag Warning is in effect. Of note, with PW approaching or exceeding 1.50 inches, or roughly 200 percent of normal, these storms should not only be wet, but could produce heavy rain as well. Should a storm pass directly over a recent burn, such as the East Evans Creek fire, mud and debris flows are possible down any adjacent drainages. Later this week (Thursday/Friday), eastward movement in the upper level pattern is likely, which is likely to shift the region of instability east of our area with drier SW flow aloft winning out. As such, lightning risk will diminish to almost nil by Thursday, but at the expense of enhanced southwest to westerly winds during the afternoons and evenings east of the Cascades, which could overlap with low humidity, especially on Friday and Saturday. Any new fire starts would then have the ability to spread/grow quickly. A Fire Weather Watch is in place for this for Friday and Saturday afternoons/evenings in FWZs 624, 625, 284, and 285. Conditions will ease during the overnight period, with generally poor to moderate recoveries, poorest along the Warners of Modoc County. The dry, diurnally breezy pattern looks to last this weekend and into early next week. But, temperatures should also lower some compared to earlier this week. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Fire Weather Watch from Friday afternoon through Saturday evening for ORZ624-625. Red Flag Warning until 11 PM PDT this evening for ORZ617- 622>625. CA...Fire Weather Watch from Friday afternoon through Saturday evening for CAZ284-285. PACIFIC COASTAL WATERS...Small Craft Advisory from 11 PM this evening to 11 AM PDT Thursday for PZZ370-376. && $$

263 FXUS66 KEKA 222130 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 230 PM PDT Wed Jul 22 2026 .SYNOPSIS...Monsoonal moisture has exited the region, ending the risk for isolated thunderstorms. Today, the remnants of the tropical storm will cool the interior, and aid in warming most coastal areas. Drier weather is expected late in the week with temperatures near or slightly below seasonal normals for the interior. && .DISCUSSION...Today, the remnants of Tropical Storm Elida (now a weaker non-tropical surface low pressure system) will move closer to Northwest California as it continues north. As a result, southerly offshore flow will continue to keep max temperatures along the coast slightly warmer than average. This will especially be prevalent from southwest Humboldt, through the coastal Eel River Valley and around Humboldt Bay. Generally, southerly gusty winds (gusting from about 20 to 25 mph) will also affect coastal headlands around Cape Menocino and the King Range up to Humboldt Bay; and interior ridges from extreme northern Mendocino up through Trinity County. There is a 75 to 80 percent chance for gusts over 30 mph for exposed coastal ridges around the King Range and between Cape Mendocino and Ferndale this afternoon and early evening. Winds will quickly die off this evening as the surface level low pressure system moves away from the region. Thursday through early next week, the surface level low pressure system will move away from Northwest California while the upper level low will still exert influence over the region. Cooler, more seasonal temperatures will continue for the whole region late this week and through the weekend. Meanwhile, a deeper diurnal coastal stratus layer is anticipated along coastal areas. At the same time, an upper level high pressure system centered over the Southwestern US will try to edge into the region bringing generally drier and warmer conditions for interior regions of Northwest California. /JLW && .AVIATION...Most terminals in Northwest California have cleared out to VFR this afternoon. However, southerly flow along the coast has made coastal stratus stubborn and persistent for Del Norte County and the coast from Cape Mendocino south through Shelter Cove to Westport. These coastal terminals have maintained IFR to MVFR conditions into early afternoon. Some lifting could occur in these areas into early evening. A deeper stratus layer is anticipated for coastal terminals late this evening and overnight bringing potential for IFR to LIFR ceilings. Due to the deep marine layer, stratus will make it further inland which could potentially affect KUKI with MVFR ceilings. /JLW && .MARINE...A remnant tropical system is passing through the waters Today. As it passes, areas of near gale strength southerly wind gusts will continue in the northern waters around and north of Cape Mendocino, including the northern inner waters from the mouth of the Eel River to along Humboldt and Arcata Bay. These winds will quickly ease tonight. Winds and seas will then remain low for the remainder of the week and gradually shift northward by late weekend. JJW && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png

732 FXUS66 KMTR 222335 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 435 PM PDT Wed Jul 22 2026 ...New AVIATION, MARINE... .KEY MESSAGES... Updated at 1234 PM PDT Wed Jul 22 2026 - Breezy onshore winds return late this week and into the weekend - Temperatures near seasonal averages throughout early next week && .SHORT TERM... Issued at 1234 PM PDT Wed Jul 22 2026 (This evening through Thursday night) The marine layer redeveloped overnight to around 1,800 feet in depth and resulted in inland expansion of coastal stratus. Southwest winds also resulted in favored locations in the Santa Cruz Mountains and Marin Coastal Range (Mount Tamalpais) to see drizzle and light rain at times with up to 0.16" of precipitation. With southwesterly winds forecast to persist through early this afternoon, places such as the North Bay and Monterey Bay region may only see stratus scatter out for a few hours this afternoon. As dewpoint temperatures remain in the upper 50s to lower 60s, it will remain muggy feeling throughout much of the day with higher humidity regionwide. Temperatures regionwide have fallen to slightly below average while the North Bay region is expected to be as much as 15 degrees below average. As winds shift more out of the northwest late this evening and into the overnight across the coastal waters, expecting inland expansion of the stratus once again with a return to a more typical summertime pattern. There is again the potential for mist/drizzle again tonight, yet will be less widespread. Low clouds that do develop inland are forecast to retreat to the coast by mid-to-late morning and especially so by Thursday afternoon. Maximum afternoon temperatures on Thursday are forecast to range in the upper 50s to lower 70s near the coast, in the 70s bayside, and 80s to lower 90s in the interior. The southern portion of the Central Coast has the greatest potential to exceed 100 deg F in places such as Lockwood, Bradley and Parkfield. && .LONG TERM... Issued at 1234 PM PDT Wed Jul 22 2026 (Friday through next Tuesday) The ridge currently over the Southern Plains is forecast to shift westward towards the Four Corners region over the weekend. This will work to compress our marine layer and allow for a slight warming trend across the interior. However, temperatures will remain within a few degrees of seasonal averages into early next week. As such, expecting typical ebb and flow of stratus returning into the valleys overnight and retreating to the coast by mid-to-late morning. && .AVIATION... (00Z TAFS) Issued at 415 PM PDT Wed Jul 22 2026 VFR through the evening hours with KSTS being the only exception due to a local offshore circulation (otter eddy) continuing to push stratus over the coastal range. All terminals are expected to drop into MVFR during the overnight hours with low confidence for timing and extent of potential IFR/LIFR ceilings headed into the hours before sunrise. Expect clearing time to extend into late morning/early afternoon. Vicinity of SFO...Gusty onshore flow this evening will ease after sunset with MVFR ceilings expected after midnight and late clearing times into the early afternoon. Onshore flow increases once again, becoming gusty Thursday afternoon. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Coastal stratus rapidly cleared over the past hour. Return of IFR stratus is expected later this evening and is expected to persist into the early afternoon on Thursday, with VFR expected for the remainder of the TAF period, and breezy afternoon onshore flow. && .MARINE... (Tonight through next Monday) Issued at 415 PM PDT Wed Jul 22 2026 Winds will continue to veer to the northwest overnight, then increase through the day Thursday into Friday. Moderate northwesterly flow will persist through the weekend and into next week. Significant wave heights will remain moderate this week before long period southerly swell from Hurricane Fausto reaches the coastal waters this weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 9 AM to 9 PM PDT Thursday for Mry Bay. Small Craft Advisory from 3 PM Thursday to 3 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory from 9 AM Thursday to 3 AM PDT Friday for Pigeon Pt to Pt Pinos 0-10 nm. Small Craft Advisory from 9 PM this evening to 3 PM PDT Friday for Pt Pinos to Pt Piedras Blancas 0-10 nm. && $$ SHORT TERM...RGass LONG TERM....RGass AVIATION...JM MARINE...CW Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea

042 FXUS66 KOTX 222339 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 439 PM PDT Wed Jul 22 2026 .KEY MESSAGES... - Very warm through Thursday with high temperatures in the upper 90s to low 100s. Widespread moderate and major HeatRisk. - Isolated to scattered thunderstorms Thursday morning and again in the afternoon may result in new fire starts and gusty outflow winds. - Critical fire weather conditions Friday and Saturday afternoons due to low relative humidity and winds. Any new or ongoing wildfires will be capable of spreading rapidly. && .SYNOPSIS... Hot temperatures expected through Thursday. Smoke from local wildfires will result in hazy skies and may keep high temperatures cooler than currently forecasted. Increasing moisture on Thursday may result in isolated thunderstorms Thursday morning and again Thursday afternoon. Dry and breezy winds Friday and especially Saturday will result in critical fire weather conditions. && .DISCUSSION... Today through Saturday: Hot conditions are expected to continue through at least Friday under the influence of the southwestern ridge of high pressure. High temperatures through Friday will be in the 90s to lower 100s, leading to Moderate to Major HeatRisk. This level of heat will be of risk to much of the population, especially anyone without effective cooling or hydration. Air quality alerts continue through Friday morning for much of central and eastern Washington from smoke from local and regional fires. When air quality is Unhealthy, everyone should reduce exposure. Limit time outside and avoid strenuous activity. Elevated to critical fire weather conditions are expected starting tonight and lasting through at least Saturday. An upper level low off the California coast continues to slowly meander north today, bringing increased PWATs around 180-200% of normal to the Inland Northwest. This will increase concerns for lightning starting tonight in the Cascades. Synoptic lift is not particularly impressive but ongoing thunderstorm activity in western Washington and northern Oregon tomorrow afternoon will move towards the Cascades. Elevated instability will be decent around 200-600 J/kg, sufficient for lightning strikes into Thursday morning. As such, we have issued Red Flag Warnings for much of the Cascades, Western Okanogan county, and the Okanogan Highlands starting at 2 AM tonight and lasting through 2 AM Friday. The Colville Reservation also has a red flag warning, but the morning thunderstorm activity looks to be mainly west of the area so it does not start until 1 PM Thursday. Thunderstorms will have some precipitation falling out of them with higher PWATs, but strikes outside of thunderstorm cores and gusty outflow winds up to 35 mph raise concern for new fire starts that rapidly spread. There is also a 20-25% chance of a stronger thunderstorm in the Blue mountains and the Camas Prairie tomorrow afternoon that would support gusts around 50 mph. With onshore flow Thursday afternoon in western Washington and increasing pressure gradients, Cascade gap winds around 10-15 mph with gusts up 20 mph are possible Thursday evening. Synoptic winds will continue to trend upward Friday and especially Saturday as pressure gradients continue to increase. The greatest chance for wind/low humidity overlap Friday will be in the east slopes of the Cascades, Waterville Plateau, Okanogan Valley, and Western Columbia basin with 10-20 mph southwest winds gusting around 20-30 mph. The synoptics are impressive Saturday with a 100 kt upper level jet overhead and a deepening low pressure in the lee of the Canadian Rockies. 700 mb winds will be around 30-45 kt, which is into the 99th percentile for this time of year. With that in mind, sustained surface winds will be westerly/southwesterly around 15-30 mph, with gusts around 25-45 mph. Any new or existing wildfires Saturday will be capable of very rapid fire spread. Fire weather watches have been issued for both Friday and Saturday for portions of the region. Sunday through Wednesday: The overall longwave pattern looks to remain fairly steady through next week. The desert southwest ridge will stay anchored and longwave troughing will continue in the Gulf of Alaska. This will favor elevated winds and mostly dry conditions to continue for the Inland Northwest. Temperatures will be near normal in the 80s and 90s with breezy conditions continuing. /DB && .AVIATION... 00Z TAFS: High pressure and light winds will allow smoke and haze to continue across the Inland Northwest. Smoke may intermittently reduce visibilities to MVFR across TAF sites. Some slightly higher wind gusts are expected toward afternoon to evening near the Okanogan Valley and near the Cascades, including KEAT/KOMK with gusts up to 15kts. Otherwise mid and high clouds will continue to stream into the region from the southwest. Chance for elevated showers and thunderstorms increase tonight after 09Z for the Cascades and spread into the Okanogan Highlands and northeast Washington after 12Z. A risk for stronger thunderstorms with gusty outflow winds increases after 23Z across the north Cascades and then southeast Washington and the southern ID Panhandle, including KPUW and KLWS. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate confidence in the visibility forecast at the TAF sites. Low confidence for any showers or thunderstorms at TAF sites overnight into Thursday morning. ----------------------- Confidence descriptors: Low - Less than a 30 percent chance Moderate - 30 to 70 percent chance High - Greater than a 70 percent chance For additional probabilistic information for NWS Spokane airports, please refer to the Aviation Dashboard on our webpage: https:/www.weather.gov/otx/avndashboard && .Preliminary Point Temps/PoPs... Spokane 66 97 66 95 63 91 / 0 20 0 0 0 0 Coeur d`Alene 67 95 66 94 63 91 / 0 20 0 0 0 0 Pullman 61 91 58 92 58 88 / 0 10 10 0 0 0 Lewiston 69 99 68 101 68 97 / 0 20 30 0 0 0 Colville 62 96 60 95 58 91 / 0 20 10 0 0 0 Sandpoint 63 95 63 93 60 91 / 0 20 10 0 0 0 Kellogg 64 92 61 91 61 88 / 0 20 0 0 0 0 Moses Lake 68 98 64 98 63 93 / 0 20 0 0 0 0 Wenatchee 77 98 69 97 69 90 / 10 20 0 0 0 0 Omak 72 99 68 98 64 93 / 0 30 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Heat Advisory until 9 PM PDT Thursday for Central Chelan County-Lower Garfield and Asotin Counties-Moses Lake Area- Northeast Blue Mountains-Northeast Mountains-Okanogan Highlands-Okanogan Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-Waterville Plateau-Wenatchee Area-Western Chelan County-Western Okanogan County. Fire Weather Watch from Saturday morning through Saturday evening for Eastern Columbia Basin -Palouse -Spokane Area (Zone 708)-Foothills of Northeast Washington (Zone 701)-Lower Palouse -Snake River (Zone 709)-Okanogan Highlands and Kettle Mountains (Zone 699)-Selkirk Mountains of Northeast Washington (Zone 700). Air Quality Alert until 11 AM PDT Friday for Central Chelan County-Lower Garfield and Asotin Counties-Moses Lake Area- Northeast Blue Mountains-Northeast Mountains-Okanogan Highlands-Okanogan Valley-Spokane Area-Upper Columbia Basin-Washington Palouse-Waterville Plateau-Wenatchee Area-Western Chelan County-Western Okanogan County. Fire Weather Watch from Friday morning through Saturday evening for Colville Reservation (Zone 702)-Foothills of Central Washington Cascades (Zone 705)-Methow Valley (Zone 704)-Okanogan Valley (Zone 703)-Waterville Plateau (Zone 706)-Western Columbia Basin (Zone 707). Red Flag Warning from 1 PM Thursday to 2 AM PDT Friday for Colville Reservation (Zone 702). Red Flag Warning from 2 AM Thursday to 2 AM PDT Friday for East Portion of North Cascades National Park/Lake Chelan National Recreation Area (Zone 697)-East Washington Central Cascades (Zone 696)-East Washington North Cascades (Zone 698)-Foothills of Central Washington Cascades (Zone 705)-Methow Valley (Zone 704)-Okanogan Highlands and Kettle Mountains (Zone 699)-Okanogan Valley (Zone 703). ID...Heat Advisory until 9 PM PDT Thursday for Coeur d`Alene Area- Lewis and Southern Nez Perce Counties-Lewiston Area- Northern Panhandle. Fire Weather Watch from Saturday morning through Saturday evening for Northern and Central Idaho Panhandle (Zone 101). && $$

353 FXUS66 KPDT 222318 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 418 PM PDT Wed Jul 22 2026 .KEY MESSAGES... 1. Continued dry and warm conditions *Heat Advisory in Effect* 2. Isolated to scattered thunderstorms Wednesday and Thursday *Red Flag Warning in affect for Abundant Lightning* 3. Hot, dry and windy conditions return Friday & Saturday && .DISCUSSION... Current satellite shows some cumulus beginning to pop up over central OR. So far no thunderstorms have made their way into the region as of yet. Abundant lightning is still expected through the afternoon and the Red Flag warning is in effect through 11 PM tonight. Outflow winds of 25-45 mph with small hail and heavy precipitation possible with these storms. Even with the lingering smoke, temperatures around the region have been in the upper 90s with little overnight recovery temperatures. Temperatures today are expected to reach into the upper 90s with overnight lows in the upper 60s to 70s. Due to the high daytime temperatures and moderate overnight low, a Heat advisory has been issued for the Gorge, Columbia River Basin of OR and WA, the foothills of the Blues of OR & WA as well as the Kittitas and Yakima Valley through 9 PM Thursday. Confidence in the temperatures is high (80-90%) We are already beginning to see cumulus work its way into the region in central OR. Models are still on track showing mid level moisture will continue to surge into the region bringing with it instability and the increase in thunderstorms. Isolated to squattered thunderstorms are expected to persist through the early evening hours. On the ground IMET in the region released a balloon as was able to get us some local data. The sounding shows CAPE values in the 800-900 J/km range with DCAPE values in the 1200 J/kg range. Lapse rates of 9 C/km and PWATs around 1 inch. Forecast soundings for the same area show very similar numbers as well as LIs of -3. This shows that the models are in good agreement with what is currently happening on the ground. Expect these storms to produce small hail, gusty outflow winds of 25-45 mph and the potential for heavy rain. Thursday models show the thunderstorms to be a bit more broad in spread. The Cascades could see some stray storms through the afternoon. The highest signal for thunderstorms is along the foothills of the Blues and through Wallowa County. A Red Flag Warning has been issued for abundant lightning through those areas for Thursday beginning after 1200. Models show an upper level low off the coast of the PacNW. The low will shift across the Cascades by Friday and will bring elevated winds across the region. NBM raw ensembles shows there to be 80-90% probabilities of sustained winds of 20-25 mph through the Gorge,foothills of the southern Blues, north central and central OR, Yakima and Kittitas Valleys. Saturday raw ensembles show the same probabilities for the same locations but winds are 25-35 mph sustained. This coupled with the very dry conditions on the ground fire weather conditions will be elevated. && .AVIATION /00Z TAFS THROUGH 00Z FRIDAY/... Thunderstorms are impacting BDN and RDM that are expected to last through 01Z. Afterwards, lingering showers persist in the area with 10-25 percent chances persisting a few hours after. Otherwise, haze and smoke continue to impact TAF sites in the Columbia Basin down to Central Oregon bringing MVFR to IFR conditions over the next 24-hours. Smoke will somewhat improve through late Thursday, but will continue to linger to bring visibilities down. && .FIRE WEATHER... Isolated to scattered thunderstorms expected across central OR and eastern mountains through the day today with a Red Flag Warning in effect through 11 PM for abundant lightning. Another round of abundant lightning is expected along the Blues and through the Wallowa Mountains Thursday and another Red Flag Warning has been issued for those areas. Friday will see increased winds across the region with critical RHs. This will lead to fire weather concerns for hot, dry and winds both Friday and Saturday. && .Preliminary Point Temps/PoPs... PDT 67 96 62 97 / 0 10 0 0 ALW 72 99 69 99 / 0 10 0 0 PSC 70 101 66 100 / 0 0 0 0 YKM 73 100 64 99 / 10 10 0 0 HRI 71 99 66 99 / 0 0 0 0 ELN 69 95 61 94 / 10 10 0 0 RDM 58 93 55 95 / 50 0 0 0 LGD 66 100 62 100 / 0 40 10 0 GCD 62 99 59 100 / 10 20 0 0 DLS 70 92 65 97 / 10 10 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Heat Advisory until 9 PM PDT Thursday for WAZ024-027>029. Air Quality Alert until 9 AM PDT Friday for WAZ028>030. OR...Heat Advisory until 9 PM PDT Thursday for ORZ041-044-507. Red Flag Warning from 11 AM to 8 PM PDT Thursday for ORZ694- 695-697>699. Red Flag Warning until 11 PM PDT this evening for ORZ698-700- 705. && $$ DISCUSSION...90 AVIATION...95 FIRE WEATHER...90

909 FXUS65 KREV 222049 AFDREV Area Forecast Discussion National Weather Service Reno NV 149 PM PDT Wed Jul 22 2026 .KEY MESSAGES... * Isolated thunderstorms today may produce lightning, brief heavy rain, small hail, and outflow gusts of 45 to 55 mph. * Hotter and drier weather arrives Thursday, with only isolated storm chances remaining across the southern Basin and Range through Friday. * A Fire Weather Watch is in effect Friday afternoon through Saturday evening for critical fire weather conditions across northeast California and far northwest Nevada. && .DISCUSSION... Isolated Thunderstorms Through Friday: * Early-afternoon radar and satellite imagery show the forecast area largely dry, with cumulus developing across northeast California, northern Washoe County, and portions of the western Nevada Basin and Range. The 12Z REV sounding measured 1.03 inches of precipitable water, near the 80th percentile for late July. Forecast soundings around the region contain 600-1600 J/kg of MUCAPE, DCAPE of 1200-1600 J/kg, and midlevel lapse rates of 7-8 C/km. This environment favors high-based, poorly organized storms capable of small hail and erratic outflow gusts of 45-55 mph. * Thunderstorm chances of 15-25% will favor northeast California and northern Washoe County, as well as Mono and Mineral counties, before shifting into the western Nevada Basin and Range this evening. Forecast soundings indicate west to northwest storm motions (265-300 degrees) at 15-25 kt, supporting east to southeast movement around 20-25 mph. This should limit the threat for prolonged heavy rainfall, although brief heavy rain remains possible beneath stronger cells. Southwest flow pushes the deeper moisture east Thursday, leaving 10-20% storm chances mainly across Mono, Mineral, and eastern Churchill counties through Friday. Hot, Dry and Windy Into the Weekend: * An approaching eastern Pacific trough will flatten the western side of the Four Corners ridge and strengthen southwest flow across the region. Temperatures rise Thursday and peak Friday, with upper 90s to lower 100s across western Nevada valleys and 80s in Sierra communities. Moderate HeatRisk is expected Friday, with pockets of Major HeatRisk across the western Nevada Basin and Range. * Afternoon west to southwest gusts of 25-35 mph will overlap minimum RH of 5-10% Friday and Saturday. The strongest overlap will occur across northeast California and far northwest Nevada, where 3-8 hours of critical conditions are possible each afternoon. Winds may activate holdover fires from this week`s lightning. Dry and breezy conditions linger Sunday before winds ease early next week, with typical late-July warmth and mostly dry weather continuing through Wednesday. -Johnston && .AVIATION... * VFR conditions prevail through this evening, with haze possible at KRNO through 22/21Z. Isolated thunderstorms should remain outside the main terminal areas, but may produce lightning, brief mountain obscuration, and outflow gusts of 35-45 kt. Afternoon west winds will gust 15-22 kt before easing between 23/03-07Z. KTRK is expected to develop LIFR fog and low stratus after 23/04Z, with 1/2SM visibility and ceilings near 200 feet possible into Thursday morning. * RNO: VFR conditions prevail, with south-southwest winds shifting west-northwest and increasing to 14 kt with gusts near 22 kt between 23/01-05Z before becoming light overnight. Dry and VFR conditions continue Thursday, followed by stronger afternoon winds Friday and Saturday. Hotter temperatures will increase density- altitude concerns. -Johnston && .FIRE WEATHER... * Isolated thunderstorms are expected this afternoon across northeast California, northern Washoe County, the eastern Sierra, and portions of the western Nevada Basin and Range. Dry lightning potentially causing new fire starts will be the main concern today, as storm motions are fairly fast around 20-25 mph. Gusty outflow winds of 45-55 mph are also possible around these storms. * A drying and warming trend begins Thursday, although a 15-20% chance of storms in Mineral and Mono counties continues Thursday and Friday. Friday and Saturday will be the two main days of concern this weekend. Increased winds gusting to 35 mph and afternoon minimum RHs ranging from 5-10% will overlap each afternoon across northeast California and far northwest Nevada, yielding 3-8 hours of critical fire-weather conditions. For this reason, and due to the proximity of these conditions to the Biscar Fire, we have issued a Fire Weather Watch from 1 PM Friday through 9 PM Saturday. -Justin && .REV Watches/Warnings/Advisories... NV...Fire Weather Watch from Friday afternoon through Saturday evening NVZ458. CA...Fire Weather Watch from Friday afternoon through Saturday evening CAZ270-278. && $$

721 FXUS66 KSTO 221920 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1220 PM PDT Wed Jul 22 2026 .KEY MESSAGES... - Slight chance for a shower or isolated thunderstorm this afternoon and evening over the Sierra Crest and southern Cascades. - Elevated fire weather conditions Friday and Saturday within the Burney Basin due to low relative humidity and breezy westerly winds. && .DISCUSSION... Visible satellite shows interior northern California clear this afternoon, with temperatures climbing across the area. Temperatures reach into the 90s for the northern Sacramento Valley and northern San Joaquin Valley this afternoon and evening. A Delta breeze develops this afternoon/evening helping to keep temperatures cooler in the Delta and southern Sacramento Valley, with highs in the upper 80s today. Monsoonal moisture has pushed further toward the east today, but isolated thunderstorms chances remain for areas east of the Crest this afternoon and evening. Best chances remain further into Nevada where the instability axis, moisture influx, and synoptic forcing is higher. None the less there is still a less than 10 percent chance for an isolated shower or storm along the crest and in northern portions of Shasta county this afternoon and evening. Breezy onshore winds will continue through today and tomorrow, with gusts up to 25kts at times for parts of the Valley. Temperatures will be seasonable across the area through the end of the week and into the weekend, with the warmest conditions around Redding. As we move into Friday and Saturday, winds increase for parts of the southern Cascades and into the Burney Basin, with periodic gusts to 25kts. Conditions will be dry across much of the area, and especially in the Burney Basin over the weekend. Elevated Fire Weather Conditions are expected within the Burney Basin Friday into Saturday due to the low RH values combined with the breezy westerly winds. We will keep an eye on any higher wind potential Friday and Saturday for the Burney Basin and if any additional headlines are needed. Otherwise, dry conditions are expected for the area over the weekend and into early next week. Synoptic levels show the ridge of high pressure building back through the western United States signaling a return to above normal temperatures for interior Northern California. && .AVIATION... VFR conditions prevail through the TAF period. SKC to FEW clouds this afternoon and evening, with breezy conditions for RDD and RBL out of the south. Gusts up to 20kts will be possible this afternoon and evening. Breezy conditions as well for the other TAF locations, with gusts up to 20kts. FEW to SCT clouds move in near 10-14z for the Sacramento sites through MOD and SCK. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

023 FXUS65 KMSO 221952 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 152 PM MDT Wed Jul 22 2026 .DISCUSSION... KEY MESSAGES: - Monsoon moisture drives thunderstorms through Thursday, bringing a localized flash flood threat. - Hot, dry, and breezy conditions this weekend will be a concern for critical fire weather conditions. - Smoke from the Pacific Northwest wildfires will continue to impact air quality, potentially worsening over the weekend. Showers and thunderstorms are developing this afternoon across Lemhi county into southwest Montana. These storms will be capable of producing moderate to heavy rainfall with slow progression to the northeast. The combination of slow moving and heavy rain could create localized flash flooding conditions. The areas of greatest concern will be the steep terrain around Salmon Idaho and the Anaconda/Butte area. The monsoonal moisture shifts to the east on Thursday so the threat of heavy rainfall diminishes, but isolated to scattered thunderstorms will still be prevalent across the Northern Rockies. A low pressure system is still on track to move into the Pacific Northwest Friday into Saturday. Winds aloft will strengthen during this period causing gusty westerly winds during the afternoon hours. On Friday, the strongest winds appear to be across west central into northwest Montana. Then, on Saturday, the focus shifts toward north central Idaho into southwest Montana. The combination of gusty winds and low minimum humidity readings will lead to near-critical fire weather conditions. The long term models indicate that the Northern Rockies will be under southwesterly flow Sunday through much of next week. This flow pattern will keep the region warm with afternoon gusty winds. The guidance is showing a lack of moisture moving into the region so the threat for afternoon convection is very low. && AVIATION... Wildfire smoke across the region will continue to slightly decrease visibility through the long-term forecast. Afternoon convection today will feature wet, slow-moving thunderstorms capable of producing brief periods of MVFR or IFR weather conditions from 22/2000z through 23/0200z mainly impacting KSMN and KBTM. Thunderstorms will also be capable of producing erratic outflow gusts up to 30 mph. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

911 FXUS65 KBOI 230000 AFDBOI Area Forecast Discussion National Weather Service Boise ID 600 PM MDT Wed Jul 22 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Numerous showers and thunderstorms today across the central Idaho mountains. Thunderstorms may produce heavy rain, creating a risk of flash flooding and debris flows, especially over burn scars and steep terrain. - Isolated to scattered showers and thunderstorms elsewhere today and Thursday, with brief heavy rain and gusty winds possible. - Areas of smoke will continue through the week. - Very hot, dry, and breezy to end the week. && .SHORT TERM /Through Friday Night/... Issued 308 PM MDT WED JUL 22 2026 Showers and thunderstorms are already ongoing across the west- central ID mountains and SE Oregon. A Flash Flood Watch remains in effect for the Wapiti burn area this afternoon and early evening following this threat. Synoptically, the upper-level ridge centered across the south-central U.S., combined with an upper-level trough off the coast, will continue to transport monsoonal moisture across the area under southerly flow aloft. A shortwave impulse is lifting north out of Nevada, which will continue producing numerous showers and thunderstorms over the west-central ID mountains through evening. Thunderstorms will be capable of producing heavy rain, creating a risk of flash flooding and debris flows, especially over burn scars and steep terrain. Additionally, instability will continue to build this afternoon for isolated to scattered showers and thunderstorms across most of southeast Oregon and the higher terrain south of the Snake River in southwest Idaho. Heavy rain will be possible in stronger storms with gusts to 45 mph. Most lower elevations will see a less than 10% chance of showers and thunderstorms today. Areas of smoke from regional wildfires will persist today, especially across east-central Oregon and west-central Idaho into the Treasure Valley. On Thursday, the flow aloft will turn southwesterly aloft as the ridge axis starts to move east, pushing deeper monsoonal moisture out of the area. However, a weak impulse ahead of the trough off the coast will bring a 10-30% chance of showers and thunderstorms to eastern Oregon and western Idaho in the afternoon and evening. Instability will extend into the lower elevations, bringing a better chance for thunderstorms to reach the Treasure Valley than previous days. Storms will be capable of gusty winds up to 50 mph. Otherwise, southwest flow will bring hotter temperatures with lower valleys forecast to reach around 100 degrees. This has prompted a Heat Advisory from 2pm MDT Thursday to 9 pm MDT Saturday. On Friday, temperatures will be very hot with lower valleys approaching 105 degrees. Winds will become breezy in southeast Oregon starting Thursday then becoming widespread across the area Friday, with gusts 20-35 mph overspread the higher elevations. Much drier air will arrive from the west, limiting thunderstorm potential to south-central Idaho and increasing fire weather concerns. Southwest flow aloft will transport some of the smoke away from the area, but drainage winds each night will continue to bring smoke impacts to some areas. && .LONG TERM /Saturday through Wednesday/... Issued 308 PM MDT WED JUL 22 2026 Sunday looks slightly cooler than Saturday, especially in Oregon zones, as part of the upper trough off the northwest coast moves inland across WA. Most of our CWA will be sunny and dry but monsoon moisture will still clip south-central Idaho, with a slight boost from Hurricane Fausto as it heads westward across the subtropical Pacific. Forecast has a 15 percent chance of thunderstorms in Twin Falls County Sunday. Monday through Wednesday should be dry in all areas and several degrees cooler than previous days, as more of the upper trough off the northwest coast comes inland. && .AVIATION /00Z Thursday through Friday/... Issued 542 PM MDT WED JUL 22 2026 Generally VFR. Areas of MVFR visibility due to wildfire smoke, mainly in eastern Oregon, gradually improving this afternoon through evening. Scattered thunderstorms mainly over SE Oregon through around 03Z this evening. Thunderstorms may bring heavy rain, wind gusts to 40 kt, local MVFR conditions, and mountain obscuration. High density altitude due to heat continuing through sunset. Surface winds: W-NW 5-15 kt , becoming mostly variable under 10 kt tonight after sunset. Winds aloft at 10kft MSL: NW 5-10 kt. KBOI...Generally VFR. Brief MVFR visibility due to wildfire smoke. Variable outflow gusts to 20 kt from distant thunderstorms to the east possible through 23/03Z. High density altitude this evening due to heat. Surface winds: NW 5-10 kt until 03Z, then light and variable tonight through Thursday morning. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Air Quality Alert until 2 PM MDT Friday for IDZ011-012-014-033. Fire Weather Watch from Friday afternoon through Saturday evening for IDZ401-402-423. Heat Advisory from 2 PM Thursday to 9 PM MDT Saturday for IDZ012-014-016-033. OR...Air Quality Alert until 2 PM MDT /1 PM PDT/ Friday for ORZ061>064. Fire Weather Watch from Friday afternoon through Saturday evening for ORZ670>675. Heat Advisory from 2 PM MDT /1 PM PDT/ Thursday to 9 PM MDT /8 PM PDT/ Saturday for ORZ063-064. Red Flag Warning until 11 PM PDT this evening for ORZ670>672. Red Flag Warning from noon MDT /11 AM PDT/ to 9 PM MDT /8 PM PDT/ Thursday for ORZ673>675. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise AVIATION.....JY SHORT TERM...CH LONG TERM....LC

729 FXUS65 KLKN 221735 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1035 AM PDT Wed Jul 22 2026 .KEY MESSAGES... * Very high atmospheric moisture content today * A few strong thunderstorms possible throughout Northern and Central Nevada this afternoon into this evening * Marginal risk of excessive rainfall in most of Northern and Central Nevada this afternoon into this evening * Moderate risk of heat-related illnesses throughout Northern Nevada Friday afternoon && .DISCUSSION... (This afternoon through Tuesday) WEATHER PATTERN OVERVIEW: An anticyclone aloft will be centered over the South Central United States this afternoon. Monsoonal moisture will remain in place in most of Northern and Central Nevada, resulting in isolated to scattered thunderstorms this afternoon into this evening. There is a marginal risk of excessive rainfall in most of Northern and Central Nevada this afternoon into this evening. Here are thunderstorm probabilities for select locations in Eastern Nevada on Wednesday, July 22nd, 2026: Ely - 55% Lund - 53% Great Basin National Park - 51% Currie - 50% Eureka - 46% Wells - 45% Ruby Lake - 44% Spring Creek - 42% Elko - 40% Jackpot - 35% The aforementioned upper-level area of high pressure will expand northwestward Thursday through early next week. As a result, storm chances will dwindle Thursday through Sunday, before ending by Monday of next week. A warming trend is expected Thursday and Friday. By Friday afternoon, high temperatures throughout Northern and Central Nevada will be around five degrees above normal for this time of year. Heat-sensitvie ground in Northern Nevada will have a moderate risk for heat-related illnesses Friday afternoon. A Heat Advisory may be required. Here are probabilities of triple digit heat for select locations in Northern Nevada on Friday, July 24th, 2026: Winnemucca - 95% Battle Mountain - 95% Crescent Valley - 95% West Wendover - 65% Carlin - 65% Elko - 55% McDermitt - 45% Orovada - 30% FORECAST CONFIDENCE & DEVIATIONS: High forecast confidence regarding very high atmospheric content today. High forecast confidence in a few strong thunderstorms throughout Northern and Central Nevada this afternoon into this evening. High forecast confidence regarding a marginal risk of excessive rainfall in most of Northern and Central Nevada this afternoon into this evening. High forecast confidence in a moderate risk of heat-related illnesses throughout Northern Nevada Friday afternoon. No deviations from the NBM model output. && .AVIATION... VFR conditions will prevail at all terminals through at least the next 24 hours. Showers/thunderstorms are expected in the vicinity of KELY, KTPH, KBAM, KWMC, and KENV this afternoon into this evening. Direct terminal impact cannot be ruled out. The strongest thunderstorms could produce erratic wind gusts near 40 knots and reduced visibility in heavy rainfall. && .FIRE WEATHER... A few strong thunderstorms are possible this afternoon into this evening. The primary hazards will be small hail, wind gusts near 45 mph, and cloud to ground lightning strikes. Enhanced runoff and localized flooding is possible in storms that form over areas with antecedent rainfall from the past few days (especially portions of 470 and 425). && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...87 AVIATION...87 FIRE WEATHER...87