025 FXUS66 KSEW 181036 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 336 AM PDT Thu Jun 18 2026 .SYNOPSIS... Upper level ridge centered well offshore with northerly flow in the lower levels. Weak system moving by to the north Friday night and Saturday. Low level flow going back to onshore Saturday. Ridge moving east Sunday ending up over the area Monday into Tuesday with high temperatures inland just a few degrees short of records. Temperatures cooling Wednesday with developing low level onshore flow. && .SHORT TERM /TODAY THROUGH SATURDAY/... Satellite imagery shows stratus over the Central and South coast extending as far east as Shelton at 3 am/10z. Clear skies over the remainder of the area. Temperatures were in the upper 40s to mid 50s except upper 50s in the Seattle metro area. Stratus will not get much further east this morning and will dissipate by late morning. Upper level ridge centered offshore with northwesterly flow aloft. Light flow in the lower levels going northerly this afternoon. This will put a cap on high temperatures near the water. For the most part highs in the 70s and lower 80s inland and lower 70s along the coast. Upper level ridge remaining offshore tonight into Friday. Flow aloft turning west southwesterly throwing a few high clouds over Western Washington at times. Lows tonight in the upper 40s to mid 50s. Highs Friday a few degrees warmer inland, in the 70s to mid 80s. Afternoon seabreeze along the coast keeping highs near 70. Weak system riding by to the north late Friday night into Saturday. This will cool the temperatures aloft over the area and induce a weak marine push in the lower levels Saturday morning. The combination of these two variables will lower high temperatures Saturday by 5 to 10 degrees with upper 60s to mid 70s over the interior and lower to mid 60s along the coast. Lows Friday night in the upper 40s to mid 50s. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Upper level ridge offshore rebuilding Saturday night and Sunday. Ridge axis moving over Western Washington Monday and Tuesday. In the lower levels low level onshore flow Saturday night going light Sunday. Thermally induced surface trough moving up from the south reaching Western Washington Monday morning. The thermal trough will remain over the area through Tuesday night then shift east Wednesday. Highs Sunday in the 60s along the coast and 70s to lower 80s inland. Monday and Tuesday will be the peak of the warm temperatures this round with 80s and lower 90s inland. Highs on the coast peaking Monday in the 70s before cooling back into the 60s Tuesday. Cooling trend starting Wednesday for the interior with highs in the 70s and lower 80s. Moderate HeatRisk over the interior Monday and Tuesday will drop back down to the minor category Wednesday. && .AVIATION... VFR conditions early this morning for interior terminals. Latest satellite imagery shows marine stratus continuing to develop along the coast. There is a 40-60% chance of MVFR cigs expected between 10z-16z, with a slight chance (10-25%) of IFR/LIFR cigs. Improvement expected in the afternoon along the coast. Widespread VFR conditions expected this afternoon. Another round of MVFR cigs possible (40-60% chance) along the coast tonight. Light to variable winds early this morning will increase this afternoon from the north to 8-12 kt. Winds will ease overnight. KSEA...VFR conditions today with high clouds at times. Light winds this morning will increase this afternoon to 7-10 kt from the N/NW. Winds will shift NE this evening after 05z-06z at 5-7 kt. 29 && .MARINE... Broad high pressure over the NE Pacific will continue into next week, maintaining northerly surface flow across area waters. Weak high pressure over are waters will weaken late tonight into Friday as a low pressure system passes over British Columbia. High pressure will rebuild over area waters on Saturday and strengthen into early next week. A combination of elevated seas and winds will continue across the coastal waters through Saturday, likely requiring the extension of the small craft advisory. Diurnal pushes through the Strait of Juan de Fuca expected this Friday into early next week. The winds on Friday and the weekend look to remain below small craft criteria (25- 40% chance). However, the winds on Tuesday will be stronger with a higher chance (40-65%) of winds exceeding 21 kt. 29 && .FIRE WEATHER... Elevated fire weather concerns Friday and again next Monday and Tuesday with minimum relative humidity values dropping to below 30 percent. In some locations Monday and Tuesday minimum RH values will be as low as the teens. Fuels will continue to dry and the atmosphere may become conditionally unstable with the surface thermal trough Monday and Tuesday. Even though the fuels have not reached critical levels fine fuels like grass and brush will ignite quickly with it being so dry. Lets be careful out there the next few days. With the flow aloft out of the west smoke from Eastern Washington will not make its way into Western Washington. Felton && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 5 AM PDT Friday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm- Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm. && $$

524 FXUS66 KPQR 180901 AFDPQR Area Forecast Discussion National Weather Service Portland OR 201 AM PDT Thu Jun 18 2026 .SYNOPSIS...Warmer than normal and dry conditions are expected to continue through the middle of next week. Confidence is increasing that hot temperatures peaking Monday and Tuesday will support Moderate to Major HeatRisk, however there remains uncertainty in the temperature forecast at this lead time. && .DISCUSSION...Thursday morning through Wednesday...There has been very little change in the forecast since the last package. An upper- level ridge axis currently centered over the northeastern Pacific will shift eastward and inland through the end of the workweek, bringing warmer temperatures with a typical summertime northerly wind pattern. Temperatures will peak on Thursday at the coast and on Friday inland as troughing aloft supports a return to stronger onshore flow Friday into Saturday. Temperatures near 70 degrees on the coast will yield Minor HeatRisk on Thursday, while inland temperatures climb into the 80s to near 90 degrees both Thursday and Friday, yielding widespread Minor HeatRisk and locally Moderate HeatRisk from Salem north to Kelso/Longview and Portland east through the Columbia Gorge. The chances to exceed 90 degrees on Thursday are only around 20-35% from Hillsboro to northern Marion County and 5-15% elsewhere for the interior lowlands. These chances increase on Friday to 35-55% from Portland/Vancouver south to northern Marion County, 15-25% in the central Willamette Valley, and 5-15% elsewhere along the I-5 corridor. Aforementioned troughing and onshore flow will yield cooler temperatures near 60 degrees starting Friday on the coast, and upper 70s to low 80s within inland valleys on Saturday. Ensemble guidance remains in good agreement that renewed ridging will develop from Sunday into early next week, raising the chances for another period of hot temperatures peaking Monday and Tuesday. Uncertainty in the position and amplitude of the ridge axis remain, leading to uncertainty in the temperature forecast, but given the model consensus, there are 70-95% chances for temperatures to exceed 90 degrees throughout inland valleys on Monday, and slightly lower chances, 65-85%, on Tuesday. The chances to exceed 95 degrees similarly peak at generally 30-80% each of Monday and Tuesday afternoon, while the chances to reach 100 degrees reach 15-35% only from Salem north to Vancouver. These daytime temperatures combined with overnight lows in the upper 50s to low 60s support widespread Moderate HeatRisk inland both Monday and Tuesday, with the coverage of Major HeatRisk largely dependent on the occurrence of overnight temperatures falling to lows only in the mid 60s. The chances of Major HeatRisk very nearly mirror those of nighttime lows of 65 degrees or warmer Monday night: 15-20% for the central Willamette Valley, increasing northward to 50% in the inner Portland/Vancouver metro, then decreasing to 20% near Kelso/Longview. Long-range guidance favors a cooling trend beginning Tuesday night and continuing into later next week, but there`s still a 20-40% chance for temperatures above 90 degrees to persist into a third day on Wednesday. -36/03 && .AVIATION...VFR and dry over the next 24 hours with weak onshore flow. Overnight cooling with onshore flow will lead to marine stratus along the north OR and south WA coast. There`s a 40-60% chance of MVFR ceilings continuing at any given time through at least 14z Thu, dissipating by 16z Thu. For coastal locations south of Clatsop county and Portland metro area terminals, chances of MVFR cigs are only around 20-30%. If any stratus forms, conditions will improve to VFR by 17z Thu. Light overnight winds will yield to another breezy day with northerly to northwesterly winds. Highest wind speeds will be along the central Oregon coast around KONP with gusts up to 20-25 kts after 17z Thu. Gusty conditions increase through the Willamette Valley between 20Z Thu and 02Z Fri, though confidence in the duration is a little less certain. KPDX AND APPROACHES...VFR through the next 24 hrs with a 20-30% chance of brief MVFR stratus around sunrise Thu. Northwest winds increase after 20z Thu to 8-11 kt with gusts up to 18-20 kt, easing again by 03-06z Fri. -03 && .MARINE...High pressure offshore will maintain a summertime pattern through this week. Diurnally driven northerlies are expected to peak each afternoon and evening through at least Friday. Winds are expected to peak each afternoon and evening with gusts to 25-30 kts, decreasing a bit in the late overnight to morning hours. Winds will likely ease over the weekend as high pressure weakens and low pressure moves into northwest WA, turning winds more northwesterly on Saturday. Seas around 7 to 9 ft at 8-9 seconds are expected to build to 9 to 11 ft at 9-10 seconds later Thursday into early Saturday as a fresh northwesterly swell persists across the coastal waters. Seas are expected to subside later Saturday into Sunday. /DH/03 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory from 5 AM to 10 AM PDT this morning for PZZ210. Small Craft Advisory until 5 AM PDT Friday for PZZ251>253. Small Craft Advisory until 5 AM PDT Saturday for PZZ271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

163 FXUS66 KMFR 181142 AFDMFR Area Forecast Discussion National Weather Service Medford OR 442 AM PDT Thu Jun 18 2026 .Updated AVIATION Discussion... && .AVIATION...18/12Z TAFs...VFR conditions prevail across the region with mid and high level clouds lingering over the area. LIFR conditions are spreading north over the marine waters and along the coast, currently around Crescent City. This will impact Brookings/Gold Beach by around 15z, eventually making it north of Cape Blanco this afternoon and reaching North Bend around 03z/19. Additionally, showers/thunderstorms will be possible this afternoon south of the OR/CA border. && .PREV DISCUSSION... /Issued 335 AM PDT Thu Jun 18 2026/ DISCUSSION...High pressure responsible for the recent heat has moved east of the region, and in it`s place, an open/weak trough has developed offshore over the eastern Pacific and will be the main weather influencer through Saturday. The two main impacts from this trough will be high temperatures lowering closer to seasonal normals (though still above normal) and a thunderstorm pattern today through Saturday (more below). 500 mb heights will lower today, which typically indicates somewhat cooler temperatures. At the surface, however, the thermal trough will push inland this morning, resulting in a slight uptick in temperatures (mid-upper 90s West/upper 80s-low 90s East) compared to yesterday`s readings. Temperatures trend cooler for Friday and Saturday the weak trough passes through the region. Afternoon highs will still be above normal, but instead of being 15-25 degrees above normal like earlier this week, it`ll "cool" to only 5-10 degrees above normal. Saturday will be the "coolest" day of the forecast period as high temperatures start trending upward on Sunday, and even more so early next week. The upper level trough offshore will bring a few days of thunderstorms to the region, starting today and peaking in terms of activity on Friday. Upper level moisture and instability is evident on satellite imagery this morning with an area of cloud cover lingering over southern OR/northern CA. Satellite derived lightning detection shows some in cloud lightning activity out beyond 130 W. Guidance indicates moisture and instability will be in the region today, focused mainly along the Sierras and into Siskiyou/Modoc counties, and this is where we expected shower/thunderstorm activity today. There could be some cumulus buildups north of the OR/CA border today, but model guidance maintains the best chances (20-30%) for thunderstorms is across southern areas. The upper trough moves closer to the coast Thursday night into Friday (a somewhat faster timing trend in the model guidance), bringing increasing moisture and instability to the region for Friday. Current guidance maintains the best chances (40-60%) in the typical areas, across northern California and east of the Cascades, but there is the potential for as far west as Jackson County (10- 30%, highest for SE areas). With the faster arrival, shower/thunderstorm activity could get going by early afternoon across northern California, with storms moving into south-central OR as the afternoon progresses. Storm motion is more southwesterly, shifting to westerly as the afternoon progresses and mid-level moisture sharply drops off farther west and north. While, this should limit storm activity west of the Cascades and north of the Siskiyous, guidance is showing the potential for shower/thunderstorm activity to move into portions of Jackson/Josephine Counties, highest chances for SE half of Jackson County (10-30% chance). Adjustments may be needed to the forecast if model trends continue this. Overall, storms are likely to be a mix of wet/dry with strong outflows (30-40 mph), lightning and small hail being the main threats. The trough axis moves through the region Friday night, taking the moisture and instability father east for Saturday. It`s possible that shower and isolated thunderstorm activity continues across Lake/Modoc Counties Friday night, which could hinder instability for Saturday. Current guidance, however, maintains enough instability to overcome this and shows some lingering thunderstorm chances across Siskiyou County northeastward into northern Modoc/southern Lake Counties. The coolest temperatures of the forecast period are expected Saturday as this trough passes through. For Sunday through the first half of next week, lingering weak troughing on Sunday transitions to shortwave ridging on Monday, then to southwesterly flow on Tuesday as a weak trough swings through to the north. Temperatures tick upward on Sunday by a few degrees with a more notable warm up on Monday under building heights. Temperatures could flirt with the triple digit mark (25% chance) again on Monday and Tuesday for the Rogue Valley. We`ll need to monitor model guidance for that trough passing through to the north in the Tuesday/Wednesday timeframe. Some guidance is hinting at the potential for thunderstorms across far eastern areas Tuesday afternoon, but we`ll also need to monitor for any potential gust winds/low RH resulting in fire weather concerns that typically accompany a dry frontal/upper level trough passage. Stay tuned for updates. MARINE...Updated 100 AM PDT Thursday, June 18, 2026...The thermal trough will push inland later this morning, bringing gradually improving conditions today into Friday. Gales will persist south of Cape Blanco and generally beyond 10 nm from shore, with very steep and hazardous seas expected beyond 5 nm from shore through this morning. Winds ease below gales later this morning and steep seas will gradually retreat westward to the outer waters by this evening, with steep seas expected for all other areas. Conditions improve moreso on Friday as winds ease below advisory criteria and steep seas retreat to the outer waters. This improvement looks shortlived, however, as gusty north winds and steep seas return south of Cape Blanco by Saturday and persist into early next week. FIRE WEATHER...Updated 300 AM PDT Thursday, June 18, 2026...The thermal trough will push inland today, bringing another uptick in temperatures across the region. Additionally, this pattern will bring dry and unstable conditions across northern California and east of the Cascades today. Meanwhile, an open trough develops offshore over the eastern Pacific on today, moving inland late Friday and east of the region on Saturday. This pattern sets up the potential for thunderstorms during this time frame, focused across northern California and east of the Cascades. Chances for thunderstorms are highest on Friday, but could begin as early as Thursday for southern Siskiyou and Modoc counties. Thunderstorm activity today looks focused south of the OR/CA border, across Siskiyou/Modoc Counties and the Sierras. As the upper level low moves closer to the coast on Friday, the chance of showers and thunderstorms increases. Current guidance maintains the best chances (40-60%) in the typical areas, across northern California and east of the Cascades, but there is the potential for as far west as Jackson County (10-30%, highest for SE areas). Storm motion is more southwesterly, shifting to westerly as the afternoon progresses and mid-level moisture sharply drops off farther west and north. While, this should limit storm activity west of the Cascades and north of the Siskiyous, guidance is showing the potential for shower/thunderstorm activity to move into portions of Jackson/Josephine Counties, highest chances for SE half of Jackson County (10-30% chance). Overall, storms are likely to be a mix of wet/dry with strong outflows (30-40 mph), lightning and small hail being the main threats. A Fire Weather Watch is in effect for abundant lightning on dry fuels for Friday afternoon/evening, including fire weather zones (FWZs) 280/281/284/285/624/625. By Saturday, the best moisture/instability shifts east, leaving some lingering chances along/east of the Warners/Winter Ridge, as well as portions of Siskiyou County from the Trinity Alps to the Medicine Lake area. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Fire Weather Watch from Friday afternoon through late Friday night for ORZ624-625. CA...Fire Weather Watch from late tonight through Friday evening for CAZ280-281-284-285. PACIFIC COASTAL WATERS...Hazardous Seas Warning until 8 PM PDT this evening for PZZ356. Small Craft Advisory from 8 PM this evening to 5 AM PDT Friday for PZZ350-356-370-376. Hazardous Seas Warning until 8 PM PDT this evening for PZZ350. Hazardous Seas Warning until 5 AM PDT Friday for PZZ370. Gale Warning until 8 AM PDT this morning for PZZ376. Hazardous Seas Warning from 8 AM this morning to 5 AM PDT Friday for PZZ376. && $$

095 FXUS66 KEKA 180701 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1201 AM PDT Thu Jun 18 2026 .SYNOPSIS...Temperatures will continue to cool through Friday with marine influence deepening and pushing more inland. Scattered dry thunderstorms will impact high terrain locations over the interior Friday. && .KEY MESSAGES... - Temperatures ease through the end of the week with only minor HeatRisk - Very slight chance of dry thunderstorms over high terrain Thursday with greater chances Friday. - A lifting but persistent marine layer at the coast. .DISCUSSION...Cooling will continue Thursday as a broad trough approaches the area. The trough will help generate some upper level clouds and pull in more marine influence, helping to drop interior high temperatures into the 80s. A deepening marine layer is expected along the coast Thursday morning. The trough will also aid in increasing upper level instability. Combined with a moisture surge up the Sacramento Valley, there is a chance (10%) of isolated, mostly dry thunderstorms over eastern Trinity Thursday evening. Thunderstorm potential will increase Friday with a 20% chance of isolated dry storms Friday afternoon over northern Humboldt and Trinity counties with a lesser chance extending as far south as the Yolla Bollys. Otherwise, temperatures will bottom out Friday with slight warming into the weekend. Seasonably warm and dry conditions are anticipated this weekend, with mostly unimpactful conditions. Long range models indicate potential for a moderate heatwave next week. /JHW && .AVIATION...An upper level low will affect area terminals through the end of the work week. Early this morning, most models indicate a coastal marine layer quickly resurging to create LIFR coastal conditions, though marine layer lifting may push ceilings closer to IFR. Satellite is already showing lower clouds starting to form along the coast. The upper level low will aid in deepening the marine layer through this morning. This means that marine influence will push further inland. In particular, marine stratus could surge up the Russian River Valley this morning which could result in IFR conditions for KUKI. && .MARINE...Strong north winds in the outer waters have gradually weakened and continue to push further offshore into very early Thursday morning with short period seas slowly falling mostly below 6 feet by Friday. Winds will be mostly calm Friday with moderate north winds rebuilding and pushing close to shore Saturday and Sunday. /JHW && .FIRE WEATHER...A now receding heatwave has left fuels much drier than they were just one week ago with ERC broadly near the 90th percentile across the interior. ERC is forecast to remain high despite increasing RH over the coming days. Overall weather conditions will greatly moderate through Friday with highs mostly in the 80s, increasing marine influence, and RH closer to 30 percent. Winds will remain gentle and terrain driven. That said, the approaching trough set to bring cooler and more moist conditions to Northwest California will also pull some tropical moisture combined with increasing instability. In combination, these two factors could create some very isolated, mostly dry, thunderstorms Thursday afternoon in far NE Trinity County (10% chance). Small waves rotating around the trough may trigger convection overnight. Some high resolution models hint at weak storm activity in the early morning hours (also 10% chance Friday. Much more robust activity is likely (25% chance) across northern Humboldt and Trinity Counties by Friday evening with lower chances as far south as the Yolla Bollys. Storm motion appears slow and isolated overall, but ignitions are still very likely given the current ERC values. Any storms could also produce some rain and gusty erratic outflow winds. /JHW && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Fire Weather Watch from late Thursday night through Friday evening for CAZ403-406-409-410. NORTHWEST CALIFORNIA COASTAL WATERS... Small Craft Advisory until 3 AM PDT Thursday for PZZ450-470- 475. && $$ 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

709 FXUS66 KMTR 181209 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 509 AM PDT Thu Jun 18 2026 ...New AVIATION, MARINE... .KEY MESSAGES... Updated at 1245 AM PDT Thu Jun 18 2026 - Hazardous beach conditions with increased risk of sneaker waves and strong rip currents. - Minor HeatRisk through the end of the week with temperatures decreasing to below normal. - Warming temperatures early next week with Moderate HeatRisk concerns by midweek in interior locations. && .SHORT TERM... Issued at 1245 AM PDT Thu Jun 18 2026 (Today and tonight) Satellite imagery early this morning indicates low clouds expanding within a 1500-2000 ft deep marine layer, which is slightly deeper than the past couple of days. The stratus will follow a typical pattern today, continuing to expand in coverage early this morning and then decreasing after sunrise before retreating back to near the coast during the afternoon. Patchy drizzle will also develop along the coast this morning. The flow will remain onshore today and increase slightly from yesterday. Winds will be breezy this afternoon and evening, especially near SF Bay and Monterey Bay as well as adjacent valleys where gusts should locally reach 20-30 mph. The marine layer and onshore winds will keep temperatures similar or a degree or two cooler near the coast today, with highs ranging from the upper 50s to around 70 degrees, generally slightly below normal. An approaching trough will further reduce temperatures inland, decreasing around 5 degrees on average from Wednesday. This will place highs in the 70s and 80s, or around 5-10 degrees below normal in most areas, resulting in Minor HeatRisk. Tonight, expect stratus to fill back in within the marine layer with patchy drizzle redeveloping along the coast. Additionally, north and east of our area, there will be enough moisture and instability ahead of the trough for showers and thunderstorms to develop. Weak elevated instability above the stable marine layer will extend just far enough south into northern Sonoma and Napa counties for a 5% chance of showers and thunderstorms in these areas. Chances for showers/storms will be even lower further to the south. The main takeaway is that while the potential for shower/storm development is very low, we cannot completely rule out an isolated shower or thunderstorm across northern areas. The long-period southerly swell will continue to bring a risk for sneaker waves and strong rip currents, with a Beach Hazards Statement out through late Friday night. See the BEACHES section for more information, but the main takeaway is to never turn your back to the ocean! && .LONG TERM... Issued at 1245 AM PDT Thu Jun 18 2026 (Friday through Wednesday) The trough off the coast will begin to move onshore on Friday, then linger over the area into the weekend. Weak elevated instability across the north will keep a 5% chance of showers and thunderstorms across northern Napa and Sonoma counties on Friday. Otherwise, temperatures will continue to trend lower, especially inland, on Friday as the marine layer deepens further and cooler air arrives with the trough. Highs near the coast should remain in the upper 50s to around 70 degrees, and inland should decrease another 5 degrees or so. Temperatures in most areas will remain similar on Saturday, but begin to increase inland by Sunday as the trough weakens. Expect stratus each night/morning with patchy coastal drizzle. Ensembles remain in agreement that a ridge will build across the West early next week. This will bring a warming trend, especially inland, with some interior locations reaching the 90s once again and Moderate HeatRisk concerns by midweek. && .AVIATION... (12Z TAFS) Issued at 426 AM PDT Thu Jun 18 2026 The marine layer has deepened to around 2000ft and spread into all terminals, with intermittent MVFR CIGs at SJC and LVK. Stratus will begin to erode from interior sites by 15-16z, closer to 18-20z for coastal sites. Southwesterly wind gusts will develop beginning around 20z for nearly all sites, with gusts around 25kts at times. Highest confidence for >25kts SFO and APC. Weaker winds and a resurgence of marine layer stratus expected again tonight generally after sunset, with similar depth and inland spread as observed this morning. Confidence for a CIG for at least an hour at LVK and SJC Friday morning are around 65-75%, with the best chances being after 10z Fri. Vicinity of SFO...Clouds struggled to make it into the terminal overnight, and intermittent MVFR CIGs will be possible through 16-17z when clouds retreat back towards the coastline and VFR sets in. Gusty onshore winds develop around 20z, with gusts around 22-25kt possible through the afternoon and evening. Low clouds move back inland likely after 07z, with around a 70% chance of MVFR CIGs at SFO by 09z. Bases expected to be right around 1500ft MSL, although could be a bit higher. SFO Bridge Approach...Marine stratus has finally push in, with some clearing just south of SFO. Clouds are expected to erode by 18-19z, with VFR prevailing thereafter. Afternoon and evening west-southwest gusts will be similar to that of SFO, with weaker after 06z Fri. Stratus will filter back in around the same time as SFO, 07-09z. Vicinity of SJC and OAK...Intermittent MVFR CIGs at SJC with more persistent stratus at OAK. Clouds will clear from south to north in the bay this morning, generally beginning around 16z, with some lingering stratus in the vicinity of OAK through 21z. Otherwise, VFR conditions should prevail for the afternoon and evening. Gusty west to northwest winds develop after 21z for both locations, weakening by 06z. Low clouds move back into OAK around the same time with bases around 1500ft MSL. Confidence in an MVFR CIG at SJC is around 70% for Friday morning, although timing looks to be significantly later, after 10z, with periods of scattering out possible. Monterey Bay Terminals...MVFR with bases around 1200-1500ft MSL currently, expecting to clear around 19-21z. Northwesterly gusts at SNS after 20z may prevent low stratus from clearing completely (40% chance), with intermittent MVFR CIGs possible through the afternoon. Either way, FEW-SCT stratus will linger near both terminals likely into the evening. As low clouds push back inland after 02z Fri, models keep clouds out of MRY for much of the night. However, seeing how sufficiently it has filled in the past few nights and given the deepening marine layer, have added MVFR CIGs for MRY beginning 04z Fri with moderate confidence. && .MARINE... (Today through Tuesday) Issued at 426 AM PDT Thu Jun 18 2026 Winds will increase this afternoon and early evening and once again on Friday afternoon and early evening leading to hazardous conditions for small crafts in the San Pablo Bay, San Francisco Bay, Suisun Bay and Monterey Bay. Expect moderate chop along with the increasing afternoon winds each day. Southwesterly swell with light to moderate seas will continue into the weekend, with moderate west to southwest winds across the outer waters. && .BEACHES... Issued at 156 PM PDT Wed Jun 17 2026 Long period southerly swell at around 15 to 17 seconds will persist through early Saturday as energetic storms in the Southern Hemisphere continue to affect the California coast, especially for south and southwest facing beaches. Hazardous beach conditions are advertised, specifically for moderate to steeply sloped beaches along the Pacific Coast of the North Bay, San Mateo, Santa Cruz counties. A Beach Hazards Statement for Pacific Coast beaches continues through late Friday night. Be sure to check beach conditions before you head out. Sneaker waves will run up the beach much farther than other waves, potentially catching beachgoers by surprise and resulting in people being swept into the water. Rip currents are strong enough to pull the strongest swimmers away from shore. Swim near a lifeguard if possible. Stay back from the beach, and away from jetties, piers, beachside rocks, and other infrastructure near the water. Never turn your back to the ocean! && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement through late Saturday night for CAZ006- 505-509-529-530. Coastal Flood Advisory until 5 AM PDT early this morning for CAZ006-506-508. PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this evening for Mry Bay-SF Bay N of Bay Bridge. Small Craft Advisory from 3 PM to 9 PM PDT Friday for Mry Bay-SF Bay N of Bay Bridge. && $$ SHORT TERM...Tangen LONG TERM....Tangen AVIATION...Zuber MARINE...JM 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

663 FXUS66 KOTX 181131 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 431 AM PDT Thu Jun 18 2026 .KEY MESSAGES... - Warm temperatures and dry conditions continue, with Friday and Tuesday some of the warmest days. - A weekend cold front will bring dry and breezy conditions and the potential elevated to critical fire conditions. && .SYNOPSIS... Today many areas will see lighter winds, except near the Cascades and central Washington where some breezy conditions linger, but these decline later today into tonight. A weekend cold front will bring breezy to gusty winds across central Washington and a return for increased fire weather concerns. Little to no precipitation is expected through the middle of next week. Temperatures remain warm and conditions dry through the next week, with Friday and early next week the warmest periods. && .DISCUSSION... ...HOT, DRY AND BREEZY CONDITIONS LATE WEEK... Today through Friday: The weather will be relatively quiet over the next couple days, as weak high pressure builds into the region ahead of a weekend trough. As the ridge builds in the jet stream shifts north and pressure gradients slacken. Winds will remain a bit breezy near the Cascades and down the Okanogan Valley this morning, then slacken. Winds will hold on longest over the Okanogan Valley. Gusts of 15-20 mph will common, with higher gusts in that Okanogan Valley up to 30 mph or so. Winds will be mostly from the north to northwest. Winds will then be relatively light until later Friday afternoon when the next system start to approach. Winds turn southerly near the Cascades and central WA and speeds increase again to around 7 to 15 mph with gusts near 20 to 25 mph. Temperatures trend milder over the next couple days, with largely 80s today and mid-80s to mid-90s Friday. Lows tonight will be in the mid-40s and 50s. Friday will see minor to moderate HeatRisk, with that moderate risk over the deeper basin and L-C Valley and near lee Cascade valleys. Friday night through Sunday: Low pressure currently near the Gulf of AK will be moving on the area by the start of this period. The low tracks across southern BC into AB into Saturday, dragging another dry cold front across the region. The jet stream sags closer to the northern border but it isn`t a strong as the jet has been over the area (like the one that brought the strong dry cold front this past Tuesday). There will be some risk for showers near the northeast WA and far north ID counties later Saturday into Saturday evening and again Sunday afternoon. A few embedded t-storms can`t be ruled out on Sunday afternoon either. Right now the risk is low, but as can happen with these systems models could be underestimating the shower potential with any instability. With all that laid out, overall most of the Inland NW will stay solidly dry. So that brings us to the next feature of the system: winds. These will continue to be breezy/gusty near the Cascades and central WA Friday evening out of the south to southwest, turning more westerly overnight into early Saturday. Meanwhile winds forecast to increase over the remainder of the area Saturday morning and peak across the later Saturday afternoon into evening. Wind start of southwest away from the Cascades and central WA, then gradually shift to northwest later Saturday and eventually winds across most of the area turn northerly. Speeds are forecast to average between 10 to 20 mph, except near the Cascades and central WA by late afternoon and evening where they will blow at 20 to 30 mph. Gusts are forecast to be between 20 to 30 mph, locally up to 40 mph near the Cascades and central WA. Winds slacken some heading into Sunday, but still remain breezy/gusty in the Okanogan Valley southward in the favored northerly flow with speeds of 10-20 mph and gusts of 20-30 mph. Temperatures will remain warm to hot this period, only cooling 2 to 5 degrees over Friday, and minimum RH values will be in the teens to low 20s. As early as Friday night and continuing into Saturday through Saturday evening, fire weather conditions will be elevated to locally critical. Given the antecedent conditions, including drying fuels and recent wildfire starts, this period will monitored closely for the potential need for fire weather highlights due to the hot, dry and windy set-up. Monday through Wednesday: A dirty-ridge builds into the region, with weak waves crossing through it during the period. There will be occasional clouds, with cumulus build-ups in the afternoon and transient middle to high clouds. The forecast remains dry, but we will have to keep an eye on Wednesday as some guidance shows a potential for some showers near the eastern mountains. Winds will be occasionally breezy, particularly near the Cascades/Okanogan Valley, but not as strong as of late with one exception on Wednesday. That will be another period to watch for elevated fire weather conditions with winds and low RH. Temperatures will be on the rise through the period, with Tuesday being the warmest day with highs in the upper 80s and 90s and a few spots pushing near 100 in the deeper basin. Each will have a minor to moderate HeatRisk, with Tuesday again the warmest of days. /Solveig && .AVIATION... 12Z TAFs: VFR conditions today. A little bit of moisture and shallow instability at mid levels this morning will result in scattered altocumulus clouds from Colville (K63S) to Sandpoint (KSZT) and Coeur d`Alene (KCOE). Breezy north winds down the Okanogan Valley (KOMK) to Ephrata (KEPH) with gusts of 20-25 kts expected. These winds will decrease in the afternoon, and the rest of the region will experience light winds through the day. A band of high clouds moves in from the south Thursday night. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in VFR conditions at all terminals through the forecast period. A fire burning near KSFF may result in a little bit of morning haze with visibility down to around 6SM. /SVH ----------------------- 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 84 52 86 56 85 54 / 0 0 0 0 0 0 Coeur d`Alene 81 53 85 57 83 53 / 0 0 0 0 0 0 Pullman 80 50 85 54 80 50 / 0 0 0 0 0 0 Lewiston 87 57 92 60 88 56 / 0 0 0 0 0 0 Colville 83 48 87 53 84 50 / 0 0 0 0 0 0 Sandpoint 79 51 83 54 82 51 / 0 0 0 0 0 0 Kellogg 79 51 85 55 81 52 / 0 0 0 0 0 0 Moses Lake 88 56 92 59 88 55 / 0 0 0 0 0 0 Wenatchee 87 62 91 63 85 59 / 0 0 0 0 0 0 Omak 86 56 90 58 87 56 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...None. ID...None. && $$

056 FXUS66 KPDT 181149 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 449 AM PDT Thu Jun 18 2026 .KEY MESSAGES... - Very warm temperatures to develop with Moderate level Heat Risk developing. - Dry air with breezy winds will bring elevated fire weather concerns over the next several days. && .DISCUSSION... Current radar and satellite depict dry and clear conditions across the region as a mid-level ridge still influences the pattern. A shortwave will enter the region Friday Night/Saturday with an area of low pressure over British Columbia that will develop locally breezy winds. Dry air is expected to prevail with minimum relative humidities dropping in the 10-18% percent range (especially in the lower elevated areas) through the next several days. Dry air in-tandem with the expected breezy winds (60-80% chance) will bring elevated fire weather concerns in the Columbia Basin, Kittitas/Yakima Region, and areas across Central Oregon. Temperatures will reach a peak (now through the weekend) on Friday with highs generally in the low to mid 90s. NBM has great confidence (>90% chance) that temperatures will at least exceed 90 degrees across the lower elevations. This will bring a moderate Heat Risk (values of `2`) across the Columbia Basin, Kittitas/Yakima Region, with isolated areas of Major Heat Risk (values of `3`) across parts of Central Oregon. We`ll see a brief relief from the heat (>85% chance) through the weekend thanks to on-coming shortwave and the broad area of trough across British Columbia. Guidance is in good agreement that a ridge just offshore will move in-land in the Monday timeframe, raising temperatures in a secondary peak in the mid to upper 90s and possibly in the triple digits by Tuesday (as advertised by the NBM). Current guidance suggests Tuesday will be the hotter day (40-60% chance) with NBM v5.0 giving 60-80% chance of the Washington Columbia Basin exceeding 90 degrees, which drops to 30-60% in the Oregon Columbia Basin, Kittitas/Yakima Region, and Central Oregon. Those percent chances jump to 70-90+% in all of the previously mentioned areas for Tuesday. Tuesday also introduces chances of high temperatures exceeding 100 degrees in the Columbia Basin at 10-20% chances. This will depend on the strength of the ridge where a stronger ridge will raise chances of experiencing 100 degrees early next week whereas chances drop with a weaker ridge. Regardless, temperatures are expected to get very warm and any heat related preparedness should be taken. && .AVIATION /12Z TAFS THROUGH 12Z FRIDAY/... VFR conditions prevail with light and variable winds through the period. SKC to SCT cloud coverage with high ceilings decks expected, with no CIG or VIS issues expected overall. && .Preliminary Point Temps/PoPs... PDT 86 55 92 59 / 0 0 0 0 ALW 87 59 93 63 / 0 0 0 0 PSC 90 58 95 62 / 0 0 0 0 YKM 89 60 95 59 / 0 0 0 0 HRI 89 58 94 62 / 0 0 0 0 ELN 86 56 91 57 / 0 0 0 0 RDM 86 49 91 50 / 0 0 0 0 LGD 85 52 91 55 / 0 0 0 0 GCD 89 50 94 54 / 0 0 0 10 DLS 91 64 95 62 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...None. OR...None. && $$ DISCUSSION...95 AVIATION...95

434 FXUS65 KREV 180923 AFDREV Area Forecast Discussion National Weather Service Reno NV 223 AM PDT Thu Jun 18 2026 .KEY MESSAGES... * Summer-like heat will maintain widespread moderate to areas of major HeatRisk today. * Thunderstorm activity increases today and tomorrow, peaking Friday. This will bring concerns for impacts to fire, recreation, and aviation on both days. * Cooler and drier weather is favored to return over the weekend followed warmer temperatures for next week. && .DISCUSSION... The latest RAP analysis of the upper air pattern this morning shows an upper ridge over the region with a subtropical trough trailing it over the Pacific. Going through today, forecast guidance projects the trough moving closer to the West Coast and breaking down the ridge. In the afternoon, a shortwave disturbance moves through the flow over the CWA as well. While the ridge still remains over the region today, well-above normal temperatures are forecast for one more day with the NE CA and W NV valleys having highs in the middle to upper 90s (some portions of W NV possibly reaching the 100 degree mark) and Sierra communities having highs in the lower to high 80s. As such, the Heat Advisory for the W NV Basin and Range continues through early tomorrow with some portions seeing Major HeatRisk. Another concern for today looks to come from potential thunderstorms within the region this afternoon. REFS SBCAPE values increase to around 500-1000 J/kg in the Sierra and the Sierra Front (higher values west of the Sierra crest). With this instability, the increased warmth in the afternoon providing lift, and PWAT values up to around 0.6 inches: these portions of the CWA have around a 15-35% chance for showers and thunderstorms today with the window opening around 1-2 PM PDT. The storms will provide increased fire weather concern within the Sierra Front today (please refer to the Fire Weather Section below or the Red Flag Warning in effect today for more information). Brief bouts of heavy rain could occur with these storms, but not anticipating major flooding issues as the ground probably can absorb a good amount of rain with the recent dry conditions. When looking at model forecast soundings, the Sierra Front also will have up to around 1500-1800 J/kg of DCAPE allowing for storms to produce increased outflow gusts up to ~50 mph later today. Please be weather aware today especially if you have outdoor plans and remember: when thunder roars, go indoors! For Friday, models show the trough making its way over the W CONUS. This pattern aloft will allow shower and storm chances within the region to increase to around 25-65% for most of the CWA for tomorrow. Recent runs of the CAMs show some morning showers developing in NE CA, but stronger storms then beginning to develop in the Quad Counties region (especially along the Pine Nut Mountains) by around noon. These storms look to move north- northeast and may not exit the CWA completely until the late evening. These storms could be a bit wetter with current QPF values in W NV ranging between a trace to around 0.25 inches. But some storms could also be on the dry side with the SPC showing a 10% dry thunderstorm for most of the CWA on Friday. A Fire Weather Watch is in effect in areas seeing the higher chances for fire weather concern on Friday though this area could expand. With similar convective parameters as those forecast for today, Friday will see similar storm hazards including gusty erratic outflows to 50 mph, lightning outside of rain cores, fast moving storms, and heavy rain under storm cores. Will be monitoring trends in case the environment becomes more favorable for severe weather. Blowing dust is also possible near desert sinks and playas if stronger gusts occur in the NV Basin and Range. Please have a way to receive the latest weather updates on Friday especially if you have recreation and travel plans. While daytime high temperatures are forecast to decrease around 5-10 degrees on Friday, they become closest to mid-June normals on Saturday. Saturday`s forecast highs for the NE CA and NV valleys will be in the middle to upper 80s while the Sierra communities will be in the middle to upper 70s range. Forecast guidance then projects the trough moving eastward and away from the CWA on Sunday followed by high pressure building over the SW CONUS going into the middle of next week. This signals dry conditions for next week with temperatures warming again to where Moderate HeatRisk is seen within W NV beginning on Monday. -078 && .AVIATION... Density altitude concerns may continue today at terminals in NE CA and W NV due to increased heating. The main concern today expects to be with showers and storms developing within the region starting around 18/21-22Z. The Sierra and Sierra Front have around a 15-35% chance for precipitation today. MVFR conditions are possible at most TAF sites should a storm develop nearby. Storms may contain increased gusty outflow winds, brief periods of heavy rain and lightning. Terrain obscuration, LLWS and turbulence may also be present near storm cores. Another round of showers and storms is forecast for tomorrow with increased chances and coverage which expect to bring additional aviation concerns. -078 && .FIRE WEATHER... Fire weather concerns increase as the thunderstorm potential within the region rises today and tomorrow. Antecedent hot and dry conditions with poor overnight recoveries have helped in drying fuels further which also raises fire danger. Storms will move quickly once developed, with a mix of wet and dry storm modes. This increases potential for dry lightning strikes outside of wet storm cores as well as dry storms that produce more lightning than moisture. Gusty, erratic outflows of 50+ mph are possible, increasing the threat of rapid wind direction shifts. A Red Flag Warning is in effect today across the Sierra Front from 1 pm to 10 pm. A Fire Weather Watch still stands for Friday, in effect from 8 am through 11 pm. HRICH/078 && .REV Watches/Warnings/Advisories... NV...Fire Weather Watch from Friday morning through Friday evening NVZ458. Red Flag Warning from 1 PM this afternoon to 10 PM PDT this evening NVZ420-421. Heat Advisory until 5 AM PDT Friday NVZ004. Fire Weather Watch from Friday morning through Friday evening NVZ423. CA...Fire Weather Watch from Friday morning through Friday evening CAZ270-278. && $$

944 FXUS66 KSTO 171945 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1245 PM PDT Wed Jun 17 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Hot and dry conditions today, followed by a cool down through the early part of the weekend. - Chances for mountain showers/thunderstorms along the Sierra today (south of Highway 50), Thursday, and Friday. && .DISCUSSION... Hot and dry conditions continue today, with highs in the 90s across the Valley and around 100 degrees in the northern Sacramento Valley. Moderate HeatRisk for today across the Valley and adjacent foothills. Delta flow will help bring temperatures down this evening and into the overnight, with west to southwesterly winds at 10-20kts. There is an isolated chance for a shower or thunderstorm in the Sierra (along the crest) along and south of Highway 50 this afternoon and evening. CAMS have hinted at these quick moving isolated showers and storms, with frequent lightning and gusty outflows possible. The ridge aloft starts to break down and shift east tomorrow through the weekend helping bring temperatures down across the area. Highs will generally be in the 80s across the Valley, with the warmest temperatures in the northern Sacramento Valley. Troughing sets into the region Thursday and Friday, with increased moisture content and instability. This brings the chance for isolated showers and thunderstorms to the mountains both days. Some of these storms could have frequent lightning, gusty outflows, quick downpours, and the potential for new fire starts where lightning happens outside of the rain. Best chances for showers and storms would be during the afternoon and early evening hours on both days. The higher instability, moisture, and coverage lies on Friday afternoon. Some of these storms may be isolated dry thunderstorms on Thursday. Elevated fire weather conditions are anticipated due to the potential for elevated mountain thunderstorms and gusty thunderstorm outflow winds Thursday and Friday. Temperatures will be at or below normal on Saturday, but start to increase as we transition back to ridging Sunday and into next week. Confidence is increasing that we return to 90s and lower 100s early next week, with low RH values and potential for breezy conditions. && .AVIATION... VFR conditions are expected over the next 24 hours. Winds will begin to increase later this afternoon and evening in the Delta, with westerly gusts up to 20kts possible for the Sacramento sites. Winds will be out of the NW to WNW for MOD and SCK this evening and out of the south for RBL and RDD. Later in the night, winds will go light and variable through 18z tomorrow. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

045 FXUS65 KMSO 180816 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 216 AM MDT Thu Jun 18 2026 .DISCUSSION... KEY MESSAGES: - A ridge building over the region today will cause temperatures to warm. - A surge of monsoonal moisture Friday night into Saturday may bring thunderstorms capable of heavy rain and gusty winds to southwest Montana and Lemhi County. Forecasts are highly confident that a strong ridge of high pressure will build across the Northern Rockies tomorrow. This weather pattern will bring quick warming, pushing tomorrow afternoon temperatures into the mid-to-upper 80s across western Montana and into the mid-90s in the lower valleys of central Idaho. Computer models show a slight chance for scattered showers to develop across western Montana this afternoon, with a few thunderstorms possible along the Continental Divide in northwest Montana. By late tomorrow night, an unusually strong surge of monsoonal moisture will move north from the Great Basin, combining with a weak upper-level shortwave. This combined moisture and energy will bring widespread showers and thunderstorms, primarily impacting Lemhi County and southwest Montana through Saturday. The main impacts from these storms will be heavy rain and sudden, strong wind gusts. Uncertainty remains regarding how far north these storms will travel, though some models show the rain and storms moving as far north as Missoula. Once this system clears out, a high-pressure ridge will quickly rebuild over the region, starting another period of hot, dry weather. && .AVIATION...A ridge centered over the U.S. West Coast will extend its influence further east into western Montana today. Since the region is on the eastern edge of the ridge, expect some gusty northwest winds in the afternoon with gusts up to 20KT. Otherwise, VFR conditions prevail. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

134 FXUS65 KBOI 181204 AFDBOI Area Forecast Discussion National Weather Service Boise ID 604 AM MDT Thu Jun 18 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Warm and dry Today with light winds. - A chance of showers and thunderstorms Friday night through Saturday. Storms Friday night and Saturday morning could produce strong outflow winds, but storms later Saturday may bring heavy rain, especially over higher terrain in Idaho. && .SHORT TERM /Through Saturday Night/... Issued 308 AM MDT THU JUN 18 2026 An upper level trough shifting eastward across the Pacific Northwest today will tighten pressure gradients across southeast Oregon and southwest Idaho. This will result in breezy west to northwest winds of 15 to 25 mph, with local gusts up to 35 mph, especially across the Western Snake River Plain and higher terrain. Combined with minimum relative humidity values dropping into the 10 to 15 percent range for lower elevations, elevated fire weather conditions are expected again today prompting the Red Flag Warning. Temperatures will be about 5 to 7 degrees cooler today from yesterday. Winds will decouple tonight as a weak transitory ridge builds into the region. Thursday looks to be a quieter, warmer day under the influence of this ridge. Temperatures will be in the upper 80s to low 90s across the lower valleys Thursday. Relative humidity values will remain quite low on Thursday, but light terrain driven winds will limit the overall fire weather threat compared to today. More active weather is expected on Friday with an incoming low pressure system moving onshore over northern California. This system will bring an influx of mid level moisture and instability into southeast Oregon and southwest Idaho. Model guidance continues to signal a distinct threat for thunderstorm development starting Friday afternoon and evening. Given initial low levels remaining relatively dry, these storms will carry a risk of dry lightning and strong, erratic outflow winds, increasing fire ignition potential. Wind gusts of 50 to 60 mph with blowing dust is possible (10% chance) especially across southeast Oregon. The ridge will reach peak amplitude over southern Idaho Friday in response to the approaching trough bringing temperatures back into the mid 90s across the lower valleys. && .LONG TERM /Sunday through Thursday/... Issued 308 AM MDT THU JUN 18 2026 As the core of the low moves closer on Saturday, moisture profiles deepen significantly, bringing a mix of wet and dry thunderstorms and increasing the threat for heavy rain and flash flooding on burn scars. The best chance for thunderstorms (30 to 60%) looks to be across the higher terrain of southwest Idaho. With precipitable water approaching the 80th to 90th percentile, the strongest storms could produce heavy rain in addition to small hail and gusty winds. Burn scars, like the Wapiti Burn Scar, will need to be monitored for flash flood potential. Cooler air accompanying the system will knock temperatures down by Sunday, returning highs closer to seasonal normals. High pressure builds back over the region early next week, leading to a return of dry conditions and a steady warming trend through Wednesday. The upper level flow remains active and thus the warming looks to be short lived. && .AVIATION /12Z Thursday through Friday/... Issued 552 AM MDT THU JUN 18 2026 VFR. Scattered mid to high clouds today. Surface winds: W-NW 5-15 kt. Winds aloft at 10kft MSL: NW 15-25 kt. KBOI...VFR. Scattered high clouds this afternoon. Surface winds: light and variable overnight, becoming NW 7-12 kt after 18/18z. Weekend Outlook...Mostly VFR. Scattered MVFR showers and thunderstorms Friday afternoon through Saturday. The stronger storms could produce outflow winds gusts up to 50 kts, blowing dust and brief heavy rain. Clearing skies Sunday with light winds. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...&& $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise AVIATION.....JDS SHORT TERM...JDS LONG TERM....JDS

519 FXUS65 KLKN 181114 AFDLKN Area Forecast Discussion National Weather Service Elko NV 414 AM PDT Thu Jun 18 2026 .KEY MESSAGES... * Dry weather and temperatures in the 90s through Friday * Heat Risk continues through Friday afternoon for those sensitive to warm temperatures * Incoming weather system beginning late Friday increases chances for thunderstorms and light precipitation along with cooler weekend temperatures && .DISCUSSION... (Today through next Thursday) WEATHER PATTERN OVERVIEW: Skies are clear across northern and central this morning. An upper level ridge circulation is centered across central Nevada this morning. By later this evening, all models are showing this circulation near the four-corners region. This will help to develop a southerly flow aloft, bringing mid- level moisture northward. Precipitable water remains about a half-inch or so and CAPE values this afternoon remain limited across central Nevada with about 100-200J/kg forecast across northern Nye and southern White Pine counties. This should bring some cumulus buildups in the central. Though the probabilities continue to remain small, cannot rule out an isolated dry thunderstorm forming across central Nevada this afternoon so will keep this in the forecast. Winds will be on the light side with occasional breeziness to 20 to 25 mph over the area. Afternoon highs will remain on the warm side with readings in the 90s. Look for quiet conditions during the tonight period with lows in the 50s. All models continue to depict the eastward progression of the upper ridge on Friday while a weak upper trough enters the frame in the eastern Pacific. Moisture continues to move northward, increasing the precipitable water values up to a half-inch to two-thirds of an inch. Surface based CAPE remains limited at 150-400J/kg but should provide enough energy once the atmosphere destabilizes during the afternoon with isolated dry thunderstorms developing across northern Nevada. The central portions continue to look dry, though winds will breezy to locally windy during the afternoon. Winds will be out of the south at 10 to 15 mph in the north but will be stronger in the central with gusts to 35 to 40 mph. In addition, any storm could produce outflow wind gusts to 55 mph. Highs will remain in the 80s and 90s. Expecting only light showers during the overnight due to cooling and rising humidity levels. Amounts remain rather modest with the highest amounts forecast to be across portions of Humboldt and western Elko counties. Lows will be in the 50s. The upper flow will switch to a more west, then a northwest direction on Saturday and Saturday night. The showers and storms will continue but remain relegated to locales north of I-80. High temperatures will be about seven to eleven degrees below recent highs as readings top out in the 80s to near 90 degrees. Winds will be breezy with northwest winds 10 to 15 mph with gusts to 25 mph. Look for gradually clearing skies during the overnight with lows in the 40s. Sunday through Thursday, models are depicting the upper ridge returning to the area with highs climbing back into the low to mid 90s early next week with lows in the 50s. FORECAST CONFIDENCE & DEVIATIONS: Modification to the NBM forecast was required to include isolated dry thunderstorms for central Nevada this afternoon. Also, increased slightly the wind speeds/gusts for Friday afternoon across central Nevada, and increase the coverage of isolated dry thunderstorms across northern Nevada tomorrow afternoon and early evening. High confidence continues today and tomorrow with high temperatures remaining in the 90s. Confidence continues to remain low on the coverage and placement of isolated dry thunderstorms in central Nevada this afternoon and the dry convection in the north on Friday. && .AVIATION... VFR conditions are expected for the upcoming 24 hour period. Winds will be less than 15 knots across the northern zones KWMC-KBAM- KEKO-KENV with gusts up to 25 knots over KTPH and KELY this afternoon. && .FIRE WEATHER... Mid-level moisture will be moving across the central fire zones this afternoon, bringing isolated dry thunderstorms to the area. By Friday, an upper level ridge will be centered over the four- corners region, and in combination with an upper trough over the eastern Pacific, will bring isolated to scattered dry thunderstorms to much of northern Nevada. In addition, winds will become breezy to locally windy across central Nevada with gusts to 35 mph across central Nevada. Headline fire weather watches have been previously issued and are on track this forecast period. These will be allowed to continue as-is. The atmosphere is expected to moisten during the overnight Friday for isolated to scattered showers and isolated thunderstorms in the north. A mix of wet and dry showers and thunderstorms will continue Saturday across the northern zones with cooler temperatures prevailing. Look for dry weather Sunday through next week with high temperatures climbing back into the 90s by early next week. && .LKN Watches/Warnings/Advisories... Fire Weather Watch from Friday morning through Friday evening NVZ425>427. Fire Weather Watch from Friday afternoon through Friday evening NVZ424-437-438-469-470. && $$ DISCUSSION...86 AVIATION...86 FIRE WEATHER...86