869 FXUS66 KSEW 240337 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 837 PM PDT Wed Jul 23 2025 .UPDATE...Onshore flow will increase tonight, which will allow for stratus to spread eastwards into Puget Sound through Thursday morning. Otherwise, clouds will clear in the afternoon for the interior. No major forecast updates this evening. && .SYNOPSIS...Cooler and cloudier conditions begin to usher in tomorrow as an upper level ridge flattens by a trough slowly moving in from B.C. that will arrive this weekend. Warmer temperatures are on tap to return early next week as ridging return. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...A calm and sunny afternoon today across western Washington. The marine layer eroded quickly this morning, allowing temperatures to warm rapidly into the low to mid 80s across most of the interior, with the warmest temps in the Cascade valleys and along the foothills. Cooler conditions along the coast where clouds are still scattering, but still expected to pop up into the mid 60s. The marine layer will redevelop and should blanket most of the interior, making for another cloudy morning on Thursday with lows in the 50s. With the weak upper level ridge deamplifying tonight as a trough from northern British Columbia moves southward, we will see stronger onshore flow, with highs moderating a few degrees into the mid to upper 70s. The cooling trend continues into Friday as the trough continues to slide southward into our region. Mostly cloudy for most of the day with slim chances for some drizzle across the north Pacific Coast and the northern Cascades. Friday looks to be the coolest day as the trough begins to eject eastward, through Saturday will be very similar to Friday, with highs in the low to mid 70s. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/...Sunday will mark the start of another warming trend. The large high pressure system that has been dominating much of the southern and central U.S. will begin to retrograde and build westward, resulting in a building ridge over the Pacific Northwest. This will result in temperatures getting back into the low to mid 80s, and with continued onshore flow, can likely expect the pattern of morning clouds and afternoon sun. The main core of the system will remain well to the southeast, with no indication of excessive heat in western Washington at this time. 62 && .AVIATION...Northwesterly flow aloft will gradually become more zonal by midday Thursday. Northwesterly to westerly flow at the surface will shift south to southwesterly overnight tonight. Most locations seeing speeds generally 4-8 kts, with OLM and HQM running slightly faster. Winds ease to 5 kts or less for all terminals overnight before increasing to around 8-12 kts by Thursday afternoon. Widespread VFR conditions over W WA this evening with the exception of HQM as lingering stratus is starting to push inland. Forecast remains consistent with this stratus moving inland overnight, at least reaching PWT, while most east Sound terminals may see some scattered low to mid clouds. PAE may be the exception, but like 24 hours ago, some degree of model uncertainty. Will need to continue to evaluate. Stratus lift/recede by late Thursday morning with fair skies expected for the remainder of the TAF period. The exception will be HQM, where there may be some improvement...but no better that MVFR conditions. KSEA...VFR this evening with westerly winds 5 kt or less before shifting more south to southwesterly overnight. Another marine push early Thursday morning resulting in SCT low clouds but potential for MVFR conditions to emerge between 12-16Z. Will continue to monitor near-term and hi-res models, but this potential will likely merit a TEMPO group at least. Any stratus will lift by 18Z with fair skies for the remainder of the TAF period. && .MARINE...Broad surface ridging centered offshore and low pressure east of the Cascades will remain in place today with a diurnally driven push through the Strait of Juan de Fuca generating SCA winds this evening. Another upper trough moving into British Columbia Thursday into Friday will increase onshore flow, with a Gale Watch in effect through the Strait of Juan de Fuca Thursday afternoon through Friday morning. Troughing over area waters will continue through the weekend, with a series of weak fronts moving inland. S Seas will remain benign through the period, generally staying between 3 to 5 feet. 15 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 1 AM PDT Thursday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. Gale Watch from Thursday afternoon through late Thursday night for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. && $$

389 FXUS66 KPQR 240414 AFDPQR Area Forecast Discussion...Updated Aviation National Weather Service Portland OR 913 PM PDT Wed Jul 23 2025 .SYNOPSIS...Warm and dry weather continues today, with inland highs climbing into the upper 80s to low 90s. Temperatures cooling into the low to mid 80s by Friday, right around seasonal normals, continuing through the weekend. A warming trend may return early next week as high pressure rebuilds over the western U.S. && .DISCUSSION...Wednesday Afternoon through Tuesday...Satellite imagery Wednesday afternoon shows mostly clear skies across NW Oregon and SW Washington. Marine stratus that had formed along the coast has mostly dissipated. Today will be the warmest day of the week, with interior temperatures reaching the upper 80s to low 90s, bringing Moderate HeatRisk to many valley locations. Overnight lows in the mid 50s to low 60s will continue to provide some overnight heat relief tonight. Thursday and into the weekend, an upper-level trough gradually settles into the Pacific Northwest, lowering upper heights and introducing a modest cooling trend. Interior temperatures will ease into the low to mid 80s across the valleys by Friday, near to a few degrees above normal for mid-July. Coastal highs will hold steady in the 60s to low 70s. Patchy coastal fog and stratus may develop Thursday morning under persistent onshore flow, clearing by late morning. Meanwhile, a weak upper low over north-central California is expected to linger through Friday, though its position remains too far south to significantly impact our area. Still, a low chance (~10 %) of thunderstorms exists over the Lane County Cascades Thursday and Friday due to residual mid-level moisture and instability. Coverage remains uncertain and is not currently included in the official forecast, but it bears watching. Onshore flow will persist throughout the week, supporting nightly marine cloud development along the coast, with some potential for early-morning incursions into the interior before clouds dissipate by mid-morning. Looking ahead to Sunday and Monday, ensemble models suggest a stronger low pressure system dropping southeast from the Gulf of Alaska, tracking toward Haida Gwaii. This system may reinforce troughing over the Pacific Northwest temporarily, keeping temperatures stable through the weekend. However, ridging over the central U.S. is expected to build westward early next week. As a result, inland temperatures may rebound into the mid to upper 80s by Monday, extending the stretch of generally dry and warm weather. Additionally, this pattern could bring monsoonal moisture north into Oregon, producing the potential for thunderstorms over the Cascades on Tuesday. Confidence is low (less than 15%) at this point, but will be something to keep an eye on. ~Hall/HEC && .AVIATION...Marine stratus building back into the coast, with IFR/LIFR ceilings at coastal terminals as of 4z Thu. Stratus is expected to push up the Columbia River and around the southern edge of the Coast Range, with a 20-40% chance of MVFR cigs developing in the Willamette Valley at the far northern/southern terminals by 12z Thu (KPDX, KHIO, KTTD, KEUG). By 16z Thu, VFR returns inland as any stratus clouds clear. Coastal terminals likely see somewhat persistent MVFR or below ceilings, with a 30% chance for MVFR stratus throughout Thursday daytime hours. Northwesterly winds under 10 kts throughout the area. PDX AND APPROACHES...VFR cigs with clear skies until 12z Thu, when a 15-30% chance of MVFR stratus arrives. Any stratus that develops clears by 16z Thu, after which we return to clear sky VFR conditions. Northwesterly flow under 10 kts throughout the period. /JLiu && .MARINE...Weak high pressure will maintain northerly to northwesterly winds with gusts up to 10-15 kt through the upcoming weekend. Seas should remain around 3 to 5 ft each day. There are currently no signs that seas and/or winds will meet small craft advisory criteria this week. -Alviz/TK && .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

577 FXUS66 KMFR 240549 AFDMFR Area Forecast Discussion National Weather Service Medford OR 1049 PM PDT Wed Jul 23 2025 .Updated AVIATION Discussion... && .AVIATION...24/06Z TAFs...A mix of LIFR/IFR conditions prevail along the coast, coastal valleys and over the marine waters. Some of the marine layer will push into the northern portion of the Umpqua Basin tonight, but conditions will remain VFR at Roseburg. VFR will prevail for inland locations through the TAF period. Scattered thunderstorms are expected to develop Thursday afternoon, impacting areas mainly east of the Cascades and south of the OR/CA border. Isolated thunderstorms are possible over portions of the Rogue/Illinois/Applegate Valleys, but confidence is low for impacts to Medford (KMFR). /BR-y && .PREV DISCUSSION... /Issued 859 PM PDT Wed Jul 23 2025/ DISCUSSION...Satellite this evening shows more marine stratus making its way into the Coos and Curry County coasts. This will continue deepening into more of the coastal counties and could reach the Umpqua Basin tonight. Radar shows that a few cells have developed over the past few hours, mainly in Siskiyou and Klamath counties. This is expected to die down by 10 PM. Tomorrow is still looking like the active day as the cutoff low to our south settles and brings moisture north to our area. This will begin between 2-4 PM in Northern California with cells continuing to develop and move north, especially into Klamath and Lake counties. PWATs in Northern California are reaching 1"-1.5", and this could bring the chance for stronger storms to bring more rainfall to the area if it combats lower level dry air. A marginal risk exists for both Siskiyou and Modoc counties, and also draws into central Jackson, Klamath and Lake counties. Alongside this rainfall threat, lightning, strong winds and small hail could be a factor. Please see the previous discussion for more details on the next thunderstorm chances. -Hermansen MARINE...Updated 800 PM PDT Wednesday, July 23, 2025...Sub-advisory north winds and low seas of 5 ft or less, will persist through the weekend and likely into next week. Areas of fog and low stratus will also persist through this time. PREV DISCUSSION... /Issued 434 PM PDT Wed Jul 23 2025/ DISCUSSION... Key Messages: * Thunderstorm chances in portions of our area, essentially every day for the next week. * Thursday/tomorrow has the highest potential for widespread activity, especially in northern California and east of the Cascades. - Strong to severe storms possible - Hazards: - Cannot rule out hail around 0.50" - 1.00" - Gusts of 40-60 mph - Abundant lightning - Some isolated areas could see heavy rainfall rates - A Red Flag Warning is in effect for abundant lightning Further Details: An upper level trough is offshore from San Francisco, still far enough away that residual warm air aloft with weak ridging over our area will limit instability this afternoon/evening. Cumulus buildups are expected over the higher terrain, and a few isolated thunderstorms are expected to manage to develop over northern California and from the southern Oregon Cascades eastward. These are likely to be relatively weak, with activity mainly well south of our area...down toward Lake Tahoe. It will be a different story on Thursday as the low tracks inland toward Sacramento and kicks the ridge out of our area. This will result in an influx of mid-level moisture and create diffluence aloft. Tomorrow, Siskiyou and Modoc counties may end up with the daily prize for greatest concentration of lightning on the west coast. The Fire Weather Watch has been upgraded to a Red Flag Warning, and besides northern California, it also includes much of Klamath and Lake counties. A minority of models extend the thunderstorm activity a relatively short distance farther to the northwest into the Siskiyou Mountains and far southern Oregon Cascades. So, a cell reaching the Applegate Valley or Ashland areas can`t be ruled out. For Friday, a trend of shifting the region of late day thunderstorm activity farther south-southeastward each day will begin and continue for Saturday, and possibly Sunday. The California trough will track east of our area, with the next trough arriving at the southern Oregon and far northern California coast from the west. There is greater uncertainty beginning Sunday, but there may be only subtle changes to expand the convective region that will be expected during Sunday into Tuesday...beyond a focus on Lake and Modoc counties. The GFS is generally more enthused about thunderstorm probability during this mid-term portion of the forecast than the NBM model. To summarize, isolated coverage is forecast for central and eastern Siskiyou County on Friday afternoon/evening, extending across Modoc County and the southern portions of Klamath and Lake counties. Then, eastern Siskiyou County, into southeast Klamath, Lake and Modoc counties. Meantime, our coastal area is expected to see few breaks in the marine low clouds and patchy fog now through Sunday morning. The least impactful weather through at least Monday will be in Douglas County with temperatures remaining near to slightly above normal. In the latter portion of the forecast and into Day 8 to 10, Tuesday through mid-week, there is a wider range of solutions. But, this also includes an expansion of thunderstorm risk that could include portions of the west side. -DW && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning from 1 PM to 11 PM PDT Thursday for ORZ624-625. Fire Weather Watch from Friday afternoon through Friday evening for ORZ624-625. CA...Red Flag Warning from 1 PM to 11 PM PDT Thursday for CAZ280>282- 284-285. Fire Weather Watch from Friday afternoon through Friday evening for CAZ280>282-284-285. PACIFIC COASTAL WATERS...None. && $$

842 FXUS66 KEKA 232042 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 142 PM PDT Wed Jul 23 2025 .SYNOPSIS...An upper level low is expected to linger near the area through the rest of the week. Thunderstorms are possible in the interior through Saturday with the highest chances Thursday and Friday. Near-normal to slightly below normal temperatures expected this week. && .DISCUSSION...The upper level low influencing northern CA continues to drop to the southwest and is now off the central CA coast. This may bring slightly warmer temperatures this afternoon to the interior. There is a small chance for some dry thunderstorms in northern Trinity county. Generally it looks like it will be too dry for any storms to form, but if they form, they will likely be dry. Chances remain at around 10-15%. Thursday morning the upper level low starts to move closer to the area. South to southeast flow over northern CA starts to bring more more moisture north to the area by Thursday afternoon. Instability increases in the afternoon with the GFS showing around 300 to 500 j/kg of surface CAPE in much of Trinity county. PWATS are around 1 inch so these storms will likely have some rain with them. The soundings are still showing a fairly deep dry layer and many of the models have around 1000 J/kg of DCAPE. This will bring the potential for gusty winds in the stronger storms. Deep layer shear is only around 15 kt which should keep the storms from being very long lived. Storm motion is expected to only be around 10 to 15 kt enhancing the heavy rain threat. Overall the main threats from these storms will be lightning, locally heavy rain and gusty outflow winds. Gusts of 50 to 60 mph are possible in any stronger storms that form. These storms may linger into the evening with some elevated instability and a shortwave moving around the low. These could drift towards the coast of northern Humboldt and Del Norte counties, but confidence is low on this. Additionally there are some models that show showers from the Sierra Thursday afternoon meandering their way into Lake or eastern Mendocino early Friday morning. Instability is weakest at this time, so low confidence on thunderstorms, but an isolated shower is not out of the question. Friday brings another round of thunderstorms and the setup looks fairly similar to Thursday. The GFS is showing some of the instability farther south into northern Mendocino county. There are even some hints of thunderstorms into central or southern Mendocino and Lake counties later in the evening with some elevated instability and a shortwave moving through. Saturday the chances for thunderstorms start to diminish as the low starts to move east of the area. This will need to be monitored as it gets closer. High temperatures are generally expected to be in the upper 80s to around 90 through much of the week in the inland areas. The coast may see some partial afternoon, but generally clouds are expected to linger in the area. Early next week high pressure may start to push back towards the west coast and warm temperatures up slightly. MKK/JB && .AVIATION...Marine stratus persists along the north coast, although less organized. Broad offshore eddies continue pushing MVFR to IFR ceilings into the coastal terminals. Brief periods of scattering are possible this afternoon, especially at ACV. CEC looks to stay fully socked in with prevailing SW flow. As weak ridging compresses the marine layer to about 2K, ceilings will quickly fall back to IFR/LIFR for both terminals after 00Z as winds turn SW. Reduced viz and scattered fog are possible again overnight (30 to 50% chance for <4SM). Similarly, HREF shows a 40 to 50% chance of marine stratus returning to UKI by early Thursday morning, further aided by southerly flow overnight. && .MARINE...An upper trough is beginning to transition to a cut-off low off the coast, continuing to weaken the coastal pressure gradient and decrease winds. Gentle to moderate winds are expected for the remainder of the week as several small long period westerly swells fill into the waters. Seas 2 to 5 feet are expected, with the lightest conditions expected nearest the coast. Winds will be broadly northerly with south/southwest winds likely directly adjacent to the coast, especially overnight. && .FIRE WEATHER...Poor air quality persists for interior Humboldt and northern Trinity County due to the Butler Fire. Some improvement in air quality is possible in the afternoon with greater mixing except immediately downwind of the fire. There is a slight chance for isolated thunderstorms in northern Trinity County this afternoon. If they do form, they may be dry as PWATs are fairly low. Thunderstorms move slightly northeast for Wednesday, with an outside chance of a thunderstorm in NE Trinity County. Instability is meager both days, but chances remain at 10- 15%. Thunderstorm chances increase considerably Thursday and Friday with isolated to scattered thunderstorms possible in Trinity, interior Humboldt, and interior Del Norte. Nocturnal thunder is not out of the question over coastal areas of northern Humboldt and Del Norte. There is a low chance for thunder in Lake and eastern Mendocino early Friday morning. PWATs increase Thursday and Friday, so there is some potential for heavy downpours with stronger thunderstorms. Gusty and erratic outflow winds are likely, as well. Winds are generally expected to be fairly light and terrain driven. Interior Temperatures are generally expected to be around seasonal normals or slightly below with highs in the 80s to low 90s. RH is not expected to be particularly low in Del Norte, Humboldt and Mendocino counties, but dry afternoon RH is still possible in the valleys of Trinity and Lake. JB/MKK && .COASTAL FLOODING...A few more days of higher than normal tides expected in the Humboldt Bay area. Tonight, the predicted high tide around 11:11 PM PDT is 7.96 ft MLLW. Similar anomalies could bring the total tide to 8.66 ft MLLW. Some low lying areas around Humboldt Bay, including King Salmon, may see some minor coastal flooding impacts tonight. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Red Flag Warning from 11 AM to 11 PM PDT Thursday for CAZ203-204-211-283. Fire Weather Watch from Friday morning through Friday evening for CAZ204-211-212-277-283. Fire Weather Watch from Thursday morning through Thursday evening for CAZ212. 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

997 FXUS66 KMTR 240417 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 917 PM PDT Wed Jul 23 2025 ...New AVIATION... .KEY MESSAGES... Updated at 1221 PM PDT Wed Jul 23 2025 - Cooler than normal conditions continue through at least Saturday - Minor tidal flooding in bayshore locations along the San Francisco Bay and San Pablo Bay - Drizzle likely Thursday and Friday mornings && .UPDATE... Issued at 805 PM PDT Wed Jul 23 2025 Morning clouds finally eroded giving way to sunny skies across most of the Bay Area this afternoon. Pretty pleasant day for late July, but if you`re one who enjoys some summer heat it wasn`t here today. High temperatures topped out in the 60s near the coast and 70s to 80s inland. These temperatures are running 5 to 25 degrees below normal for late July. The real heat currently is east of the Rockies with numerous states currently under some type of heat related hazard. One other item we`ve been monitoring during the late afternoon into the evening hours were radar returns well offshore of the Central Coast. These returns are associated with an area of upper level instability and some moisture. Latest guidance keeps a few showers going over the ocean, but none overland at this time. Otherwise, tonight will feature another repeat with stratus surging inland with coastal drizzle. MM && .SHORT TERM... Issued at 1221 PM PDT Wed Jul 23 2025 (This evening through Thursday) Mostly sunny sky conditions are expected across the interior this afternoon, with temperatures some 5-15 degrees F below seasonal averages. This is due to an upper level trough across just offshore of the Bay Area. As a result, the marine layer remains around 2,500 feet in depth which should allow the low clouds to "mix-out". Low clouds return to much of the valley locations overnight with the possibility of coastal drizzle. Any drizzle that does develop will amount to a trace to a few hundredths of an inch of rainfall. Low clouds will dissipate by late morning or early afternoon. Temperatures Thursday afternoon will be similar to today. Expecting upper 50s to upper 60s near the coast, 70s to near 80 degrees across the interior, and the warmest interior spots reaching into the mid 80s. && .LONG TERM... Issued at 1210 AM PDT Wed Jul 23 2025 (Thursday through Tuesday) The cut-off low will remain in place through Friday keeping the pattern pretty stable in the medium term. Expect more cool temperatures, a robust marine layer, and morning drizzle. There is a band of mid-level moisture that looks to move through from South to North late Thursday through early Friday. This could bring another chance for high-based convection, but the probability for thunderstorms remains in the single digits. By the weekend the pattern will start to change, though you may not notice it. The cut-off low will be picked up by a dip in the jet stream. This trough will then remain just offshore keeping the natural AC pumping and temperatures below normal. At the same time, a four corners high will build bringing triple digit heat to the desert SW this weekend. While the direct impacts from this system will stay well to our SE, the periphery effects may bring our temperatures back to near normal by the end of the month. && .AVIATION... (06Z TAFS) Issued at 917 PM PDT Wed Jul 23 2025 Patches to areas of low clouds and drizzle /MVFR/ redeveloping and moving inland tonight and Thursday morning. Conditions lifting to VFR Thursday afternoon. Low clouds /MVFR/ move inland Thursday night and Friday morning. Vicinity of SFO...VFR-MVFR tonight and Thursday morning, VFR Thursday afternoon to mid evening, low clouds /MVFR/ returning Thursday night and Friday morning. West to southwest wind 15 to 25 knots decreasing to 5 to 10 knots tonight and Thursday morning. West wind strengthening to 15 to 25 knots Thursday afternoon and early evening. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Areas of low clouds gradually increasing in coverage tonight, patchy light drizzle /MVFR/ developing as well tonight and Thursday morning. VFR Thursday afternoon. Low clouds /MVFR/ return Thursday night. && .MARINE... (Tonight through next Tuesday) Issued at 805 PM PDT Wed Jul 23 2025 Gentle to moderate northwesterly breezes and low seas will prevail through the week. Low clouds with the possibility of drizzle also persists through the week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Coastal Flood Advisory until 2 AM PDT Thursday for CAZ006-506- 508. PZ...None. && $$ SHORT TERM...RGass LONG TERM....Flynn AVIATION...Canepa MARINE...Canepa 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

463 FXUS66 KOTX 240531 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 1031 PM PDT Wed Jul 23 2025 .KEY MESSAGES... - 15% chance for light showers in Northeast WA and North ID through this evening. - Warmer with breezy winds Thursday and Friday, then slightly cooler over the weekend. - Temperatures warming back into the 90s to low 100s next week with little to no precipitation chances. && .SYNOPSIS... Partly sunny skies with scattered cumulus development will continue through today with a small threat for light showers over Northeast WA and North ID. Conditions dry out for the rest of the forecast period with warmer temperatures Thursday and Friday and breezy westerly winds. Temperatures cool slightly over the weekend, then rebound into early next week. && .DISCUSSION... Rest of Today through Friday: A 15% chance for showers lingers over Northeast WA and North ID through this evening as the low pressure system that brought yesterday`s rain shifts east of the region. This will be the last time we see precipitation chances in the forecast until the middle of next week. Temperatures will warm a few degrees into the upper 80s to upper 90s Thursday and Friday with winds picking up out of the west. Sustained wind speeds will range from 10- 20 mph with gusts of 20-30 mph. Drier air will move in, dropping afternoon humidity levels to 15-25%. The lowering humidity values combined with warming temperatures and breezy winds will bring elevated fire weather concerns, particularly across the Snake River Valley, Columbia Basin, and Waterville Plateau including Wenatchee, Moses Lake, and Ephrata, none of which received a wetting rain with the system that moved through over the past couple of days. Saturday into Next Week: Temperatures will cool by 3 to 7 degrees through the weekend as a trough takes up residence over the Inland Northwest. Heading into early next week, models are in good agreement on the trough retrograding into the Pacific which would place us under higher pressure aloft and allow temperatures to heat back up into the 90s to low 100s. Not much wind is anticipated with this pattern aside from typical diurnal breezes. Overall the forecast period is looking relatively quiet in comparison to the past few days. /Fewkes && .AVIATION... 06Z TAFS: VFR conditions will be present over the aviation air space. Breezy west to southwest winds will pick up between 16-19Z Thursday and will continue through Thursday evening. Wind gusts 15 to 25 kts expected with the higher end of the gusts impacting KEAT and KLWS. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence for VFR conditions and breezy conditions./sb && .Preliminary Point Temps/PoPs... Spokane 59 90 60 88 57 84 / 0 0 0 0 0 0 Coeur d`Alene 58 90 59 86 57 83 / 0 0 0 0 0 0 Pullman 53 87 55 84 52 81 / 0 0 0 0 0 0 Lewiston 64 97 65 94 62 90 / 0 0 0 0 0 0 Colville 49 89 49 85 47 83 / 0 0 0 0 0 0 Sandpoint 53 86 55 84 52 80 / 0 0 0 0 0 0 Kellogg 60 86 60 83 58 81 / 0 0 0 0 0 0 Moses Lake 59 95 58 91 55 87 / 0 0 0 0 0 0 Wenatchee 67 93 65 88 61 85 / 0 0 0 0 0 0 Omak 60 94 60 90 57 85 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$

766 FXUS66 KPDT 240510 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 1010 PM PDT Wed Jul 23 2025 .UPDATED AVIATION...06Z TAFs...VFR conditions will prevail through the forecast period with mostly light and variable winds overnight except at RDM which will see winds near 12 kts through the overnight period. Some SCT/FEW250 CIGs will move in steadily overnight and tomorrow. Winds will increase later in the period at all TAF sites beginning around 16Z for DLS, near 18Z for ALW and 20-00Z for the remaining sites with sustained winds between 12-17 kts and gusts to near 22 kts. Bennese/90 && PREV DISCUSSION... /issued 116 PM PDT Wed Jul 23 2025/ DISCUSSION...Current satellite shows fairly clear skies across the region. Cirrocumulus clouds are developing in the Blues and Central OR in the last few hours, hinting that a pop up shower is possible through the rest of the afternoon in that area. With paintball guidance, went ahead and extended the PoP through Bend through the late afternoon hours (10-20% chance). Not expecting anything to suggest it will be a widespread precip event with it mostly secluded to Central OR. Another potential hazard for this afternoon will be haze and smoke originating from the Burdoin fire near the Dalles and Cascade gaps. Westerly winds might help transport haze and smoke to parts of the Columbia Basin in the late afternoon to early evening. The HRRR model is not showing much support for widespread coverage and observation cams does not currently show haze entering those regions. Given that, I`m not confident to enter haze into the grids, but will mention here that the chances of some passing smoke and haze in the Columbia Basin later today are low at 5-10%. Wind wise in the near term, our biggest hazard is the westerly winds coming off the Cascade gaps through Friday. We easily hit wind criteria for fire weather, but min relative humidity levels are not low enough to calculate overlap to trigger red flag warnings. Our next best chances of thunderstorms will be tomorrow in the mid to late afternoon hours (3-10PM) in the Blues and Central OR (15-25% chance). Not seeing enough moisture advection to forecast a widespread event with wetting rain amounts. A shortwave from British Columbia will push down through the weekend, giving us some slightly cooler air. Highs will drop to the mid to high 80s through parts of the Basin, with lower 80s in higher elevated population centers. A ridge is located in the south eastern part of CONUS and will slowly extend westward going through the beginning of the work week. Temperatures will begin to trend 10-15 degrees above normal by Monday and Tuesday. NBM displays triple digits through some parts of the Basin, with guidance shows 40-60% chances of exceeding 100 degrees in that same region. Tuesday and Wednesday appear to be hottest days, but will need to keep monitoring for trends to see if coverage of triple digits increases or decreases. && .PRELIMINARY POINT TEMPS/POPS... PDT 62 94 61 90 / 0 0 0 0 ALW 67 95 65 91 / 0 0 0 0 PSC 62 98 61 93 / 0 0 0 0 YKM 62 95 60 91 / 0 0 0 0 HRI 64 97 63 93 / 0 0 0 0 ELN 61 90 60 85 / 0 0 0 0 RDM 52 91 50 88 / 0 0 0 0 LGD 57 91 56 88 / 0 0 0 0 GCD 57 92 55 90 / 0 0 0 0 DLS 66 91 63 85 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...95 LONG TERM....95 AVIATION...90

197 FXUS65 KREV 232132 AFDREV Area Forecast Discussion National Weather Service Reno NV 232 PM PDT Wed Jul 23 2025 .KEY MESSAGES... * Thunderstorm activity increases this afternoon, peaking Thursday through Sunday. Potential impacts include heavy downpours and flooding, strong outflows, small hail, and lightning. * Cooler than normal temperatures expected for the rest of the week and the weekend. * A gradual warming and drying trend returns early next week, bringing highs up to near or slightly above normal. && .DISCUSSION... No significant changes from the last forecast package. The main concerns for the rest of the week and this weekend will be showers and thunderstorms across the Sierra, NE CA and the far western portions of NV. Convection is slowly starting to develop this afternoon with a cumulus field across the Sierra. The latest CAMs continue to highlight this afternoon with a few storms over portions of the Sierra from Truckee southward towards Mammoth Lakes, and over portions of NE CA. Storms will be isolated in nature, so some dry lightning is possible with them. As the closed low off of the California coast moves inland our storm chances will increase over the next few days. This system is moving relatively slow. Therefore, we are expecting widespread showers and thunderstorms, especially over the Sierra and NE CA. However, the Sierra Front including Reno-Sparks down to Minden have a good chance of seeing some storms. However, remember that storms are naturally spotty in nature. So, not everybody will see the rain. That being said the best chances for wetting rain are on Thursday through Saturday with a 30-50% of showers and thunderstorms. Sunday will be slightly drier, but still has a 10-30% chance for precipitation. The main hazards with any storm are periods of heavy rain, small hail, gusty and erratic winds, and frequent lightning. Possible impacts are localized flash flooding (5% chance of flash flooding across the over the Sierra), reduction in visibility from rain, and from blowing dust in the NV Basin and Range due to outflow winds. To add on about the Marginal Risk for flash flooding, storm motion is expected to be slow, so any storm could lead to flooding as they slowly move over the region to the north. Meanwhile, temperatures will continue to be below normal for late July through Sunday. Then temperatures increase to seasonal early next week as the moisture associated with the upper low moves away from the area. This means that temperatures will be in the mid-80s to low 90s W NV and NE CA, while the Sierra remains in the mid-60s to upper-70s. Next week, conditions start to improve as the upper low moves away from our area. This will lead to drying and warming conditions. Temperatures will rise to normal, while our storm chances drop with PW decreasing back to seasonal values. -HC && .AVIATION... VFR conditions persist with typical afternoon breezes this afternoon. KTRK, KTVL and KMMH have a 15-30% chance for showers and thunderstorms. Main hazards with any storm include erratic outflow winds and brief, heavy rainfall. Storm chances increase to 30-50% Thursday and Friday for all terminals. -HC && .FIRE WEATHER... Thunderstorm chances are expected each day through the weekend with the highest probabilities Thursday through Saturday. The main area of concern continues to be the Sierra, NE CA, and portions of far western NV. However, minimum relative humidity appears to increase each day from the 20-30% range to 25-40% by Saturday in the aforementioned areas. The best chances for dry lightning will be today and again on Sunday once humidity starts to drop. However, with the expectation of periods of heavy rain this could hinder the development of new fires. Anyway, new ignitions due to lightning are possible away from rain cores. -HC && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

259 FXUS66 KSTO 232033 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 133 PM PDT Wed Jul 23 2025 .DISCUSSION... .SYNOPSIS... Below normal temperatures continue this week. Chances for afternoon and evening showers over the mountains Wednesday into the weekend with best chances Thursday and Friday. && .KEY MESSAGES... * Today: - Afternoon highs in the 80s and low 90s throughout the Valley as below normal highs continue this week. - Onshore winds will be gusty through the Delta and into the Valley during the evening hours. - Chances for isolated mountain thunderstorms, with the highest chances south of US 50. Any storms that develop will form along the crest and move out of our area. Storms will be predominantly wet, but any lightning strikes outside the main rain core will pose the threat for fire starts. * Thursday-Friday: - Off-shore low continues to bring breezy to gusty onshore winds in the afternoon and evening. High temperatures will continue to be below July normals by 10-15 degrees - Higher chances for isolated, high elevation mountains showers and t-storms compared to Wednesday. These storms are expected to be mostly wet, but there is the potantial for isolated dry thunderstorms. Current hires guidance shows storms staying outside of our forecast area, developing initially along ridgelines before pushing further away from our area through the evening. - Elevated fire weather conditions in the mountains through Friday due to potential isolated dry thunderstorms - There is a chance for a isolated showers to develop over the Sierra foothills late Thursday night into early Friday morning, which could push further into the Sacramento Valley. However, forecast confidence is low at this time. - Below-normal high temperatures will continue through Friday and into the weekend as ensembles continue to depict offshore troughing over the area. * Long Term: - Cluster Analysis depicts upper level troughing through the weekend. As weak ridging begins to build over the Pacific NW early next week, heights aim to flatten out allowing for temperatures to warm slightly but remain below normal. - Current NBM high temp forecast around 2 to 5 degrees below normal for Monday and Tuesday of next week. .Changes from previous forecast... - Slight increases for thunderstorm development Thursday and Friday. - Low chance for isolated showers in the Sierra foothills/Sacramento Valley overnight Thursday into Friday. && .AVIATION... VFR conditions expected over the next 24 hours across Interior NorCal. For the Valley, south to southwest surface winds generally less than 12 kts with gusts up to 15 to 20 kts through 03z Wednesday and again after 21Z Thursday. For the Delta vicinity, sustained winds 10 to 20 kts with gusts 20 to 30 kts at times. Slight chance for a few low clouds around 1000-2000 ft from 08Z to 16Z Thursday in the Delta and adjacent Valley locations. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

706 FXUS65 KMSO 232118 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 318 PM MDT Wed Jul 23 2025 .DISCUSSION... KEY MESSAGES: - Warmer with isolated showers today. - Thunderstorm chances gradually increase each day, from south to north, starting Friday and lasting into next week. If you`re planning outdoor activities, have a plan to seek shelter or a safe place when you hear thunder. Scattered showers and thunderstorms will be possible this afternoon, generally across northwest Montana. As the temperatures rebound back into the 80s and 90s Thursday and Friday, expect breezy afternoons across western Montana with westerly winds of 10 to 20 mph. From this weekend into next week the Northern Rockies will be under southwest flow which increases the chances for showers and thunderstorms. This pattern differs somewhat from the climatological position of the late July upper ridge in that it will be shifted further east over the Plains and Texas. In addition, persistent troughing over the West Coast will yield multiple disturbances that will track north into our region. We have increased the chance for daily thunderstorms, well above the NBM forecast. Probabilities from ensemble guidance and also from machine learning models corroborate this move. It is also worth mentioning that the chances for nocturnal/nighttime convection is likely not captured well in the current forecast but will certainly be possible under this type of flow pattern. The latest GFS model depicts elevated, weak to moderate instability (ex. Lifted indices of negative 1 to 2) moving up and over north- central Idaho and western Montana during the early morning hours of Monday, Tuesday, Thursday and Friday of next week. This activity will be highly dependent on upstream thunderstorm evolution and could impact those who are camping out in the backcountry. As for the strength of the storms, there are increasing indications that the instability could be highest by mid-week. The NBM has CAPE values of 1,000 J/kg or higher across the region on Wednesday through Friday. For those unfamiliar, CAPE is a measure of the amount of buoyant energy available to a rising air parcel, representing the potential strength of updrafts within a thunderstorm. Additionally, there are model runs that depict a stronger shortwave ejecting out of California and into Washington State during this time late next week. If this occurs wind shear will be higher, possibly on the order of 30 to 40 knots, which could be enough for organized multicellular or marginal supercell thunderstorms capable of damaging winds, and large hail. While this is several days out, it seems like there has been consistency from run to run with the general pattern in the ensembles. On the other days starting this weekend into Monday/Tuesday, because we will be getting into the 90s for many locations, strong downbursts could be in the cards. This is also the time of year for possible flash flooding from heavy rains. However, one typical ingredient that is usually a common denominator, weak winds aloft, appears to be lacking. Be that as it may, the steering flow will be a little stronger than average, so while the storms will have decent movement there is the potential for training. All things considered, the weather next week looks quite active with growing chances for potentially beneficial showers and thunderstorms. && .AVIATION...Weak instability remains present across the region and thus widespread afternoon cumulus buildups have begun to pop with some producing brief bouts of moderate rainfall. But generally speaking, expect VFR conditions with some breezy northwest winds lasting until around sunset. Weak zonal flow is expected on Thursday with warmer temperatures and diurnal breeziness. A few stray showers could be possible near the Canadian border, but are not likely. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

003 FXUS65 KBOI 240235 AFDBOI Area Forecast Discussion National Weather Service Boise ID 835 PM MDT Wed Jul 23 2025 .DISCUSSION...Much quieter wx this evening (than previous evenings) as the northern part of an upper trough shears away across Montana into North Dakota, and the southern part leaves an upper low in the Pacific off California. Only a few weak showers along the NV border but those will end shortly after sunset. The upper low will gradually renew scattered showers and isolated thunderstorms near the NV border Thursday and Friday, then into more of our CWA Saturday when the low comes inland. Current forecast covers this well. No updates needed. && .AVIATION...VFR. Isolated showers/thunderstorms along ID/NV border this evening. Surface winds: NW 5-10 kt this evening, becoming light and variable under 7 kt tonight. Winds aloft at 10kft MSL: NW 10-20 kt. KBOI...VFR. Surface winds: NW under 10 kt this evening, becoming variable 5-8 kt tonight. && .PREV DISCUSSION... SHORT TERM...Tonight through Friday night...A weakening upper level trough to our north will slowly move east of the area tonight, allowing our flow to become SW aloft late Thursday. We will remain in SW flow for the remainder of the short term. Meanwhile, an upper level low currently off the coast of San Francisco will drift east into northern CA by late Friday night. Typically, this low might bring monsoon moisture north toward Idaho, but not in this case. Our moisture will increase slightly, but not significantly. Therefore, we will continue to see scattered showers and isolated thunderstorms over the area each day. The areal coverage is expected to increase Thursday and Friday, especially compared to today. But we do not expect to see a significant lightning event either day. Winds with storms have the potential to reach 50 mph or so each day. As we have seen the last couple of days, the core of storms will have the ability to produce brief torrential rain, but the weaker storms and showers will produce very little rain. LONG TERM...Saturday through Wednesday...A weak shortwave trough will move northeast across the area Saturday night and Sunday. Enough moisture and instability will be around for a low chance (15-30%) of afternoon/evening showers and thunderstorms Saturday and Sunday, mainly near the Nevada border and Valley County. Weak troughing will remain along the west coast Monday through Wednesday while an upper high over the southern plains retrogrades to the west. This will cause southerly flow to develop over the desert SW, Great Basin, southeast Oregon, and southwest Idaho. Impacts over the forecast areas will be increasing temperatures with lower valley daytime highs near 100 degrees. Will also need to monitor increasing moisture and potential for thunderstorms as mid and high level moisture advects northward over the region. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...LC AVIATION.....JY SHORT TERM...SP LONG TERM....TL

465 FXUS65 KLKN 230928 AFDLKN Area Forecast Discussion National Weather Service Elko NV 228 AM PDT Wed Jul 23 2025 .KEY MESSAGES... Updated at 106 AM PDT Wed Jul 23 2025 * Southerly afternoon breezes across central Nevada with gusts 20 to 30 mph thru the period * Isolated to scattered, and mostly dry thunderstorms for portions of northern Nevada each afternoon thru Saturday && .DISCUSSION... (Today through next Wednesday) WEATHER PATTERN OVERVIEW: Trof remains situated across the PacNW and NorCal today with southwesterly flow over the Great Basin. Upper closed low will split from the trof by tonight, though no significant shift in sensible weather will be noted. Southerly breezes across central Nevada this afternoon with gusts 20 to 25 mph. Winds slightly more modest across northern Nevada, though isolated dry thunderstorms are expected in and near Elko County. Occasional lightning strikes and gusty and erratic outflow winds with gusts 45 mph or more can be expected. Temperatures will reside a few degrees cooler than average across the region. Closed upper low remains poised along the California coast thru Saturday with southwesterly upper and mid level flow present over the forecast area. Southerly afternoon breezes will be expected across central Nevada thru the weekend. PWATs will remain high enough to support diurnally driven afternoon thunderstorms along and north of the I-80 corridor thru at least Saturday. Latest indications show an increase in areal coverage Thursday with isolated to scattered thunderstorms and mixed wet and dry storm modes as PWATs are indicated to increase modestly. The main focus of convective activity shifts over Humboldt County after Thursday with isolated dry thunderstorms in the area. Temperatures generally remain a couple degrees cooler than average across the forecast area. FORECAST CONFIDENCE & DEVIATIONS: High confidence in the short term forecast though exact coverage of thunderstorms slightly uncertain. Otherwise, troffing is indicated to persist over the west coast into next week. Slight shift in the flow pattern places afternoon convection further to the northwest as indicated by numerical model solutions. Though there is uncertainty as to how far to the northwest the main area of convection will migrate. But favoring a storm free solution for the forecast area at this time. && .AVIATION... VFR conditions expected at all terminals over the next 24 hours. Weak flow aloft across Northern Nevada today with gusts below 15 kts at KWMC KBAM KEKO and KENV. A cutoff low centered just off the Central California coast will help push wind gusts into the 15-25 kt range across portions of Central Nevada including KTPH and KELY this afternoon. Cumulus cloud build-ups across most of Northern and portions of Central Nevada this afternoon, with a 10-15% chance of thunderstorms at KEKO and KENV. AMD NOT SKED at KWMC due to unstable communications. && .FIRE WEATHER... Elevated fire weather conditions again present across fire weather zones 426, 425, and 427 this afternoon due to southerly wind gusts between 20 and 25 mph along with minimum relative humidity residing around 15% or less. With no significant change in the upper pattern thru the weekend, southerly breezes can be expected thru the weekend across central Nevada. Slight increase in winds indicated for Saturday with gusts up to 30 mph. Across northern Nevada, winds will be slightly more modest though isolated dry thunderstorms will be present this afternoon, focused within zones 469, 470, and 438. Thunderstorms become more widespread in areal coverage Thursday afternoon with locations along and north of I-80 seeing isolated to scattered storms. Atmospheric moisture content indicated to creep just high enough to produce a mix of wet and dry storms. Portions of northern Nevada will continue to see diurnally driven thunderstorm activity each afternoon thru at least Saturday with the main area of activity shifting to northwest Nevada. Temperatures remain a few degrees cooler than average. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...92 AVIATION...96 FIRE WEATHER...92