238 FXUS66 KSEW 152202 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 302 PM PDT Sat Aug 15 2026 .SYNOPSIS... Western Washington will remain positioned between an upper level low over the northeastern Pacific and upper level ridging to the southeast through the weekend. Isolated thunderstorms will be possible across the mountains this afternoon and evening, with the thunderstorm threat diminishing on Sunday. Another trough will move across the region early next week. A warmer and drier trend is then expected mid to late week as a ridge starts to build into the region, however shower chances may increase again by Friday as a disturbance approaches from the west. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... Western Washington will remain positioned between a weak upper level low over the northeastern Pacific and upper level ridging building in from the southeast through the weekend. The low will allow for a weak shortwave to move across the area today, with the main highlight remaining the shower and isolated thunderstorm threat for the mountains this afternoon and evening. Latest satellite imagery this afternoon shows stratus persisting along the Pacific Coast and Southwest Interior, while gradually scattering out across the interior lowlands. Meanwhile, mid- level clouds associated with shower activity continue to work their way up along the south-central Cascades. Isolated thunderstorms will remain possible for the mountains this afternoon and evening as conditions gradually become more unstable this afternoon. Elevated fire weather conditions will continue for the Cascades as a result due to lightning and gusty outflow winds in any storms that do fire up. Highs today will be in the 70s to low 80s across the interior lowlands and in the mid 60s along the coast. Ridging will build into the region from the southeast on Sunday, allowing for overall thunderstorm chances to diminish across the area with only a slight chance (15-20%) expected across the North Cascades during the afternoon and evening hours. Otherwise, expect another round of marine stratus to make its way inland during the morning and to scatter out by the afternoon. Highs on Sunday will be in the upper 70s to low 80s across the interior lowlands and in the mid to upper 60s along the coast. Monday will be similar as the the low offshore weakens and sinks southwestward. Another round of morning stratus across the area will scatter for some afternoon sun, with highs expected to be similar to Sunday - in the upper 70s to low 80s across the interior and in the mid 60s to low 70s along the coast. && .LONG TERM /TUESDAY THROUGH SATURDAY/...Ensemble guidance has become somewhat more consolidated with respect to the pattern for the middle to late portions of next week, with a lean toward high pressure building across the Great Basin and extending into the Pacific Northwest. This would bring temperatures to near to slightly above seasonal normals into the late stages of next week. While the pattern of onshore low-level flow maintaining morning clouds and clearing in the interior by early afternoon each day will prevent relative humidity values from trending too low, there is still not a significant signal for rainfall for the midweek period. This may begin to shift toward Friday as ensemble guidance suggests the next disturbance may get close enough to bring another round of shower chances. That said, there`s still around 40% of ensemble members that would favor more of a ridge pattern over the west coast that could continue to block the region from any significant weather systems. && .AVIATION... The marine stratus continues to erode across the interior this afternoon, giving way to VFR cigs. MVFR stratus confined to the coast this afternoon. There may be some brief improvement along the coast this evening, but conditions are expected to deteriorate quickly back to MVFR. Another round of stratus Sunday morning will bring a 30-40% chance of MVFR cigs and a 20-30% chance of IFR cigs to the interior terminals. Improvement to VFR Sunday afternoon after 17-18z. Winds predominantly SW this afternoon across the interior terminals and WSW along the coast. Winds will try to switch WNW across central Puget Sound terminals this evening after 00z. Light SW to calm winds tonight. KSEA...VFR conditions this afternoon. MVFR cigs possible (30-40% chance) again Sunday morning, with a 20% chance of IFR cigs after 12z Sunday. Conditions should improve in the afternoon to VFR. SW winds this afternoon 5-7 kt winds will shift more W/NW between 02- 06z around 4-5 kt. Light SW winds overnight into Sunday morning. Guidance suggests WNW return Sunday afternoon. 29 && .MARINE... Broad high pressure over the Pacific will maintain light winds over the coastal waters. High pressure will then expand into area waters on Sunday and strengthen into next week. This will lead to increased NW winds over the coastal waters into next week, but are expected to remain below SCA thresholds. Seas will be around 3-6 ft through Monday. Seas will build slightly on Tuesday and become steep around 6-8 ft with a dominant period of 7 seconds over the outer coastal waters. Steep seas look to continue through Thursday. Diurnally driven westerly winds will continue to occur each afternoon and evening through the Strait of Juan de Fuca this weekend with gusts likely (70%+ chance reaching SCA thresholds. The westerly pushes look to start to weaken starting on Monday into late in the week with a 30% or lower chance of winds reaching SCA thresholds. 29 && .FIRE WEATHER... Elevated fire weather conditions will continue across the Cascades today with slight chances (15-20%) of thunderstorms possible along the Cascade crest this afternoon and evening. Overall chances for convection will diminish into Sunday as upper level ridging builds into the area from the southeast. By Sunday, expect convection to largely be confined along the far Northern Cascade crest and areas generally east of the crest. Continued onshore flow and excellent overnight humidity recoveries will then help mitigate fire weather conditions through early next week. While some uncertainty remains in the long term pattern, ensemble guidance has increasingly come to consensus that a warming and drying trend is likely mid to late week, before the potential for shower and thunderstorm chances increases again late week as the next disturbance approaches from the west. This could potentially reintroduce some elevated fire weather concerns to the area. && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory until 5 AM PDT Sunday for Central U.S. Waters Strait Of Juan De Fuca-East Entrance U.S. Waters Strait Of Juan De Fuca. && $$

244 FXUS66 KPQR 152030 AFDPQR Area Forecast Discussion National Weather Service Portland OR 130 PM PDT Sat Aug 15 2026 .SYNOPSIS...Seasonably warm and dry conditions expected through the next week with morning clouds and afternoon clearing. Low chances for Cascade thunderstorms this afternoon, which may result in lightning with briefly heavy rain and erratic winds. && .DISCUSSION...Now through Friday...Seasonable conditions with no weather impacts expected through the next week. The large-scale pattern looks to remain fairly stagnant through the period, with broad and relatively flat upper-level ridging over the majority of CONUS and weak positively-tilted upper troughing over the Northeast Pacific. This pattern will support continued onshore flow, maintaining near-normal daily high temperatures in the 80s within inland valleys and 60s along the coast, and overnight lows in the 50s across the region. A transient shortwave tracking overhead today yielded isolated light rain showers this morning, however dry conditions are expected through the remainder of the day west of the Cascades as the best forcing slides northward into Washington. The robust marine layer has thus far supported overcast skies, but latest satellite imagery depicts cloud cover beginning to erode, with increased sunshine expected through this afternoon. Above the low-level inversion, there is some available instability to generate high-base showers or thunderstorms, but those low chances (15-25%) are restricted to the Cascades where showers or storms may instead be surface-based. Any passing storms will be capable of producing lightning as well as briefly heavy rain and erratic winds. Chances for thunder fall below 5% this evening. The next chance for light showers or Cascade thunderstorms appears to be on Monday when the next weak shortwave passes overhead, however the probability of accumulating rain is less than 5% away from the immediate Cascade crest. There is increasing consensus that upper-level ridging over the Rockies and Great Basin will build late in the workweek, which could favor warmer temperatures Thursday and Friday afternoons. A potential passing system Friday into next weekend will bring higher chances for rainfall, however uncertainty remains high at this lead time. -36 && .AVIATION...Through 18z Sunday...Widespread marine stratus west of the Cascades continues to support low-end MVFR cigs at 1.5-2 kft across the airspace late this morning. Modest clearing will see a trend to VFR cigs inland by 19-21z Sat and high-end MVFR cigs with a 40-50% chance of VFR cigs at coastal terminals by 21-23z Sat. Isolated rain showers have largely dissipated aside from along the Cascades, with the chances for rain or thunder now at 10% or less west of the mountains. Otherwise, hazy skies may continue to restrict slantwise vis while terminal observations maintain 7-10 SM at the surface. Light winds this morning will build to 5-10 kt out of the northwest this afternoon, then ease below 5 kt tonight. KPDX AND APPROACHES...Low-end MVFR cigs below 2 kft are expected to trend to VFR as skies clear and cloud bases lift, with a 50% chance of VFR conditions by 20z Sat. West to northwest winds expected throughout the period, increasing to around 5 kt this afternoon, then easing tonight. -36 && .MARINE...A largely stagnant pattern continues through much of the next week with high pressure offshore supporting northerly to northwesterly winds of 8-15 kt and gusts up to 20 kt. Benign seas of 3-6 ft persist through the period. -36 && .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

079 FXUS66 KMFR 152131 AFDMFR Area Forecast Discussion National Weather Service Medford OR 231 PM PDT Sat Aug 15 2026 .KEY MESSAGES... * Low chance of thunderstorms in the Cascades and northern Klamath and Lake counties this afternoon and evening. * The potential for thunderstorms continues on Monday evening mainly east of the Cascades. * Warm weather persist most of next week. * Upper level energy could bring another round of thunderstorms Friday into next weekend. && .DISCUSSION... Satellite has a lot of weather features this afternoon with some coastal stratus moving into the Umpqua Valley. In addition, there is plenty of cumulus build ups over the higher terrain around the valleys and northern Klamath County. Finally, smoke from fires in northern California are spilling into Siskiyou County this afternoon. As for the forecast, The high resolution ensemble forecast(HREF) system is showing convective activity in the higher Cascades around Crater Lake later this afternoon and evening. This is the area we have the highest confidence in thunderstorm activity. The national severe storms laboratory(NSSL) model is predicting some thunderstorm activity around Jackson County this afternoon. However, that model is usual to ambitious with thunderstorms, so we feel the probability of anything occuring is around 1-3 percent, so not impossible. Otherwise, we`ll likely see another marine surge into the Umpqua valley later tonight with models giving a 50% chance of it pushing back into the Umpqua Basin later tonight. Heading into Sunday and Monday, the upper level charts become fairly interesting. We should see a short wave move into Oregon with two upper level lows combining and moving around each other in the Pacific. In any case, all this upper level energy will give us a small chance of thunderstorms in northern Lake and Klamath Counties on Monday. By Wednesday, the GFS has 500 mb heights building and temperatures will trend slightly warmer into the mid 90`s for highs here in Medford. This is right around our normal high for mid August. This ridge remains in place through Thursday before the next upper level wave pushes through around Friday into Saturday next weekend. Once this wave moves through, the majority of ECMWF ensemble members are keeping us dry. However, we see about 4 out of 50 are excited about rain or convection over our section of Oregon. Therefore, there is some disagreement about about how much moisture and lift is around Friday. Odds are it will remain dry. Overall, the upper level charts are fairly interesting through the forecast period, although on the ground impacts will likely remain low for the public and the region through next week. -Smith && .AVIATION...15/18Z TAFs... VFR conditions continue farther inland this morning and early afternoon with cumulus build ups along the higher Cascades. MVFR ceilings are continuing along the coast and are anticipated later tonight. Those MVFR ceilings could push into Roseburg(KRBG) overnight. Aside from the cloud cover, there is a <5% chance of thunderstorms in the vicinity of MFR later this afternoon evening. -Smith && .MARINE...Updated 330 PM PDT Saturday, August 15, 2026...Light north winds will persist tonight before trending later tonight into Monday. Conditions will become hazardous to small crafts with gusts to 30 knots 10 to 20 nm offshore south of Cape Blanco. Winds will ease a bit before increasing again Tuesday evening. -Smith && .MFR WATCHES/WARNINGS/ADVISORIES... OR...CA...None. PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM Sunday to 2 AM PDT Monday for PZZ356-376. && $$

248 FXUS66 KEKA 152140 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 240 PM PDT Sat Aug 15 2026 .KEY MESSAGES... * Smoke spreading overnight from local and distant wildfires, pushing eastward during the diurnal swing as winds pick up out of the north. * Cooler temperatures as upper wave troughing pattern stalls over the area. && .SYNOPSIS...An upper level troughing pattern has stalled over the greater PACNW. Inland areas can expect cooler temperatures with the coast continuing to have overcast conditions and brief afternoon clearing. Generally mild weather is expected for the next week. && .DISCUSSION...Troughing continues over the area through the weekend and into early next week. This has supported a much deeper marine layer with stratus reaching far inland, along with moderated interior temperatures. Near to below normal temperatures are expected to continue through much of the week as the troughing continues. High pressure may briefly rebuild early to mid week, but models are not showing a significant warm up and interior temperatures are likely to remain near normal (with most valleys in the 90s). Coastal areas are seeing stratus persist through the afternoon,and this is likely to continue so long as afternoon winds remain light. Even then, only partial afternoon clearing is likely. All said, generally mild, seasonable weather is expected for the next week. && .AVIATION...With an extremely deep marine layer, ceilings have lifted despite up stream high pressure filling in after the passing shortwave. The overall synoptic pattern is a stalled open wave upper level trough which will contribute to overnight overcasts conditions but with the deep marine layer, lifting ceilings fairly quickly during the day time transition. MVFR conditions will set in after 18z or so for the coastal terminals, if the current pattern persists. KUKI had a few hours of IFR/LIFR overnight and with moisture and calm winds it could repeat tonight but guidance has low probability of such an occurrence. /EYS && .MARINE...Northerly winds are diminishing in the northern waters with isolated areas south of Cape Mendocino accelerate around the point this evening at 30-33kts. No advisories at this point but that could change by mid week as northerlies build in the southern inner and outer waters. A long-period southerly swell of ~3ft has built into the region and will mix with northerly shorter period waves. However, the overall sea state should remain mixed with these two wave groups through the start of next week. Light to moderately breezy (~20kt) winds are expected through the extended forecast. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png

186 FXUS66 KMTR 152320 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 420 PM PDT Sat Aug 15 2026 ...New AVIATION... .KEY MESSAGES... Updated at 1234 PM PDT Sat Aug 15 2026 - Gradual warming and drying trend into next week && .SHORT TERM... Issued at 1234 PM PDT Sat Aug 15 2026 (This evening through Sunday night) A gradual warming and drying trend is forecast over the next few days as high pressure over builds westward over the Four Corners region. However, a modest marine layer is forecast to persist and result in cooler conditions near the coast. Near the coast, temperatures are forecast to be in the 60s to low 70s, bayshore and coastal valleys are likely to warm into the low 70s to low 80s, and mid 80s to low 90s across the far interior. Breezy onshore winds are expected each afternoon and evening with gusts to between 20-30 mph in the favored gaps/passes and down the Salinas Valley. Tonight, expecting another round of drizzle and/or mist along the coast and in the favored upslope coastal regions of the Bay Area. Temperatures will largely cool into the 50s to low 60s. As stratus retreats to the coastline by mid-to-late morning and early afternoon on Sunday, expecting temperatures to be a few degrees warmer than Saturday afternoon. && .LONG TERM... Issued at 1234 PM PDT Sat Aug 15 2026 (Monday through next Friday) A more notable warming and drying trend will begin on Tuesday as the mid/upper level ridge builds further to the west and spreads over the Desert Southwest. However, lingering troughiness off of the Pacific Northwest will maintain a shallow marine layer and afternoon temperatures slightly below average throughout much of next week. Overnight/morning minimum temperatures will be near normal. Above the marine layer`s influences, dry conditions are expected especially Tuesday and beyond. && .AVIATION... (00Z TAFS) Issued at 420 PM PDT Sat Aug 15 2026 Generally MVFR stratus lingers through the afternoon across the immediate coast with VFR conditions across the rest of the region. Moderate and gusty onshore pattern winds will persist into the evening hours. Overnight, IFR-low end MVFR stratus is expected to expand inland. Stratus will clear Sunday morning with breezy onshore winds expected to return in the afternoon. Beyond the TAF period, expect a compressing marine layer to lower stratus ceilings on Sunday night and limit expansion of the stratus deck inland. Vicinity of SFO... VFR conditions through the evening hours with moderate and potentially gusty west-northwest winds. IFR-low end MVFR stratus will return this evening with low confidence on the exact timing, although the model output consensus agree on the stratus developing by 06Z. Stratus clears out late Sunday morning with breezy onshore winds resuming in the afternoon and a low confidence that stratus returns in the evening before the end of the TAF period, with greater confidence in stratus impacts after it ends. SFO Bridge Approach... Similar to SFO. Monterey Bay Terminals... MVFR-IFR stratus will develop through the next couple of hours across the terminals. Breezy west winds continue through the evening hours, turning light overnight. Stratus will mix out Sunday late morning and early afternoon (moderate confidence at MRY, high confidence at SNS), with breezy northwest winds expected in the afternoon and evening hours. Stratus may return to MRY right at or shortly after the end of the TAF period. && .MARINE... (Tonight through next Thursday) Issued at 206 PM PDT Sat Aug 15 2026 A gentle to moderate northwesterly breeze persists into early next week with localized fresh gusts possible across the interior waters. A long period southerly swell of about 16 to 18 seconds will linger through Sunday. Winds increase to fresh to strong early next week and remain elevated through the end of the forecast period. Seas subside this weekend before building to 7 to 9 feet mid week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...None. && $$ SHORT TERM...RGass LONG TERM....RGass AVIATION...DialH 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

405 FXUS66 KOTX 152250 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 350 PM PDT Sat Aug 15 2026 .KEY MESSAGES... - Continued thunderstorm chances focused over mountain areas through the weekend. - Temperatures warm back into the mid 80s to mid 90s by Sunday. - Drier air returns early to mid next week. && .SYNOPSIS... A somewhat active pattern persists across the Inland Northwest through the weekend and into early next week with continued mountain thunderstorm chances each afternoon and evening. Temperatures trend warmer through the weekend and into next week. A drier airmass moves in by the middle of next week. && .DISCUSSION... Today and Sunday: Due to a low pressure system retrograding off the PNW coast, the Inland Northwest will remain in southwesterly flow for the next couple days. This will provide PWATs 100 to 150 percent of normal (0.75 to 1 inch). Small disturbances passing through will provide enough instability combined with daytime heating alongside added moisture to result in chances for thunderstorms each afternoon and evening this weekend. For this afternoon and evening, much of the northern mountains and valleys, Cascades, Palouse, Spokane/CdA, and ID Panhandle have a 10 to 20 percent chance of thunderstorms. Today`s soundings indicate elevated PWATs 0.60 inches and above and DCAPE values near 1000 J/kg, favoring gusty outflow winds near 40 mph. Additionally, lightning induced fire starts are possible. These higher PWATs will keep fire concerns at elevated rather than critical for all areas but the Lower Palouse and Snake River. For this zone (709), a Red Flag Warning has been issued through 9pm. Main impacts in this area include lightning occurring in an area that has been dry, especially away from any heavy rain cores, and gusty outflow winds that could increase fire spread. Tomorrow, soundings show thunderstorms with similar characteristics and threats as today, but highest chances will be further confined to the mountains. Areas above that had a 10 to 20 percent chance of thunderstorms will see chances much closer to 10 percent. Monday through Friday: The low off the PNW coast will remain there through the middle of the week, resulting in higher heights building over the region to start the work week. With waves still moving through, chances of precipitation and isolated thunderstorms remain Monday and Tuesday, but are confined only to the mountains with areas elsewhere having near zero chances. These chances will taper off after Tuesday as a warmer and drier air mass moves in. Near the end of the week, a quarter of the clusters show the low moving northeastwards and towards the region, which would favor a cooler, wetter end of the week. However, 75 percent of the clusters favor continued ridging over the area as the offshore low weakens. Temperatures will remain at or just above normal through mid-week, then warm to 4-6 degrees warmer than normal as ridging remains over the area. /AS && .AVIATION... 18Z TAFs: VFR conditions will prevail through the 24 hour TAF period with isolated MVFR visibilities possible due to smoke. Confidence in visibility impacts is too low at this time to bring TAF visibilities lower than 6SM for all terminals apart from EAT. Smoke models keep EAT at MVFR/IFR for the majority of the TAF period. The threat of showers and, to a lesser degree, thunderstorms, will be present across much of the region through around 06Z. GEG, SFF, COE, PUW, and LWS all have a TEMPO group for showers. The chance for thunderstorms is too low to include in TAFs at this point, though LWS has recorded a couple instances of thunder in their METARs so far this evening. After around 06Z, winds become light. There is a chance for thunderstorms and showers tomorrow as well, but chances are low enough to not include in TAFs at this time. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: High confidence in smoke and haze continuing to impact local terminals, but low confidence in extent of reduced vis/cigs. High confidence on showers and isolated thunderstorms being present in parts of the region Saturday afternoon but low confidence on storms impacting specific TAF sites. This is the most impactful high alternate scenario and any incoming thunderstorms would result in amendments. /AS ----------------------- 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 56 88 57 89 59 87 / 30 20 20 0 0 10 Coeur d`Alene 56 87 57 88 59 86 / 30 20 20 0 10 10 Pullman 49 86 51 87 51 84 / 30 20 20 0 10 0 Lewiston 61 91 64 92 63 91 / 30 20 20 0 20 20 Colville 46 86 47 87 48 86 / 20 20 20 0 20 10 Sandpoint 49 82 50 84 51 82 / 20 20 20 0 0 10 Kellogg 54 83 55 84 56 82 / 30 20 20 0 0 10 Moses Lake 58 89 59 91 58 89 / 10 0 0 0 0 0 Wenatchee 65 88 66 90 66 89 / 20 0 10 0 0 0 Omak 61 89 61 91 62 90 / 40 10 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until noon PDT Tuesday for Central Chelan County-Okanogan Highlands-Okanogan Valley-Upper Columbia Basin-Waterville Plateau-Wenatchee Area-Western Chelan County-Western Okanogan County. Red Flag Warning until 9 PM PDT this evening for Lower Palouse -Snake River (Zone 709). ID...Air Quality Alert until noon PDT Tuesday for Lewis and Southern Nez Perce Counties-Lewiston Area. && $$

952 FXUS66 KPDT 152254 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 354 PM PDT Sat Aug 15 2026 .KEY MESSAGES... - Isolated to scattered showers and thunderstorms today with abundant lightning and gusty winds, mainly over eastern Oregon. - Lower (<20 percent) chances of showers and thunderstorms Sunday and a 20-30 percent chance of showers Monday with a (<20 percent) chance of thunderstorms mainly from the Blue Mountains eastward. - Increasing winds later Monday into Tuesday. && .DISCUSSION... Southwesterly flow remains over the Pacific Northwest. Low pressure will move from near British Columbia to well off the Oregon and California coasts by Monday afternoon. This will allow for a more split flow pattern to develop early next week, which should keep things dry. A ridge will build back over the area by midweek, with a return to southwest or south flow possible thereafter. The showers and thunderstorms that affected portions of the Columbia and Blue Mountain foothills earlier have weakened and were moving out of the area. Additional showers and thunderstorms were expected to develop mainly from the Blue Mountains eastward this afternoon. Any thunderstorms could contain gust winds and abundant lightning. A Red Flag Warning remains in effect for mainly the eastern Oregon Mountains through this evening. The model guidance is in reasonable agreement that thunderstorm activity on Sunday will be significantly less and further east. While isolated activity can not be ruled out, especially over Wallowa County, it does not appear to be widespread enough to warrant any kind of additional headlines. Activity could possibly be a bit higher on Monday, but looks to be mainly over Wallowa County. As we go from Monday into Tuesday, a split flow develops and winds will increase across the area. There will be some gustiness developing Monday evening, but the better chances are Tuesday afternoon across the Cascade gaps, Kittitas Valley, Simcoe Highlands, Columbia Basin and Gorge. Winds could gust 20 to 30 mph in these areas. RH values will also decrease from Monday into Tuesday. NBM probabilities of wind gusts >= 25 mph are >70 percent in these areas. However, with the exception of the Kittitas Valley, NBM probabilities of wind gusts >=39 mph are less than 40 percent. Will need to see how these winds evolve over the next few days to see if any headlines will be needed, but fire weather concerns will at least be elevated. The midweek period looks dry before the south or southwest flow returns and an upper low comes into play as well. All of these features could bring additional chances of precipitation by the end of the week. && .AVIATION /00Z TAFS THROUGH 00Z MONDAY/...VFR conditions to prevail through the period. An upper weather system moving through the area today will continue to produce scattered to isolated thunderstorms across the Blue mountains into this evening. Thunderstorms are not expected to impact any sites. Winds will increase to 12-20kts with gusts 20-30kts at site DLS this afternoon, becoming light around or after 05Z. Breezy winds will develop at sites RDM/BDN with gusts up to 20kts this afternoon, becoming light late in the evening hours. Winds will otherwise remain light through the period at all other sites. Lawhorn/82 && .FIRE WEATHER... Red Flag Warnings remain in effect through this evening for far eastern Oregon for potential thunderstorm development, which already appears to be underway in portions of Wallowa County. Any thunderstorms could bring abundant lightning and wind. For Sunday and Monday, thunderstorms chances will be less (<20 percent) and mainly confined to these same areas, though chances could be a bit higher on Monday than Sunday. At this time, there are no plans to extend the Red Flag Warning or issue another one for Sunday due to the lower probabilities and much less areal coverage. Current thinking is no headlines will be needed for Monday either, but will reevaluate that with each subsequent model run. The next concern then becomes gusty winds later Monday into Tuesday, which could be in the 25 to 30 mph range, coupled with decreasing humidities. Fire weather concerns will be elevated, but will need to see how things do or don`t come together for any fore weather headlines. && .Preliminary Point Temps/PoPs... PDT 56 88 58 89 / 0 0 0 0 ALW 62 90 64 91 / 10 0 0 0 PSC 57 93 59 93 / 0 0 0 0 YKM 60 91 61 93 / 10 0 0 0 HRI 60 91 62 92 / 0 0 0 0 ELN 58 86 59 88 / 10 0 0 0 RDM 49 86 52 87 / 10 0 0 0 LGD 54 89 57 90 / 20 10 0 20 GCD 54 91 56 90 / 0 0 0 10 DLS 63 89 62 91 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until noon PDT Monday for WAZ026-522-523. Red Flag Warning until 9 PM PDT this evening for WAZ692-693. OR...Air Quality Alert until noon PDT Monday for ORZ041-503-505-506- 508>511. Red Flag Warning until 9 PM PDT this evening for ORZ692>695- 699. && $$ DISCUSSION...77 AVIATION...82 FIRE WEATHER...77

114 FXUS65 KREV 152002 AFDREV Area Forecast Discussion National Weather Service Reno NV 102 PM PDT Sat Aug 15 2026 .KEY MESSAGES... * Generally a warming and drying trend this weekend. * A 10-20% chance for showers and thunderstorms remain through the weekend for Southern Lyon, Mineral, and southeastern Churchill Counties. * Warming to near normal for next week, with afternoon westerly breezes. Showers or thunderstorms may return late next week. && .DISCUSSION... * While much of the moisture the region has dealt with the past several days is being scoured out of the region, it`s still present across southern and eastern Nevada. For western Nevada, the 12Z KREV sounding still indicated PWATs of 0.71". The atmosphere is certainly more stable, but there is just enough moisture present to keep 10-20% chances for showers and thunderstorms today and Sunday across Southern Lyon, Mineral, and southeastern Churchill Counties. The HREF agrees with this as well, even showing a bit more coverage Sunday as compared to today, due to increased surface heating. * A shortwave traversing through the Pacific northwest will bring a slight uptick in our typical afternoon westerly Zephyr breezes on Monday, primarily in far northeastern California and northwestern Nevada, closer to the Oregon border. There`s a 40% chance for gusts to exceed 30 mph for a few hours in the late afternoon. While not indicative of widespread critical fire weather, it`s certainly eyebrow raising given recent wildfires and will need to be monitored. * A high pressure center expands westward through the week bringing warmer temperatures, with highs returning to the 90s in lower elevation valleys. Increasing instability, along with moisture sneaking in under the ridge will bring low end chances (10-20%) for storms the middle into the end of the week. A few ensemble members are more aggressive with the moisture surge, so there is a 5% chance for more expansive shower and thunderstorm coverage. * The other item to keep an eye on is a trough late next week off the northern CA coast, which deepens southwest flow over the region. The probability for wind gusts exceeding 30 mph is increasing for late week into next weekend, which may bring fire weather concerns. -Dawn && .AVIATION... * Widespread VFR conditions this weekend, outside of low end (10- 20%) chances for showers or thunderstorms across Southern Lyon, Mineral, and southeastern Churchill Counties from approximately 21z-02z. Elsewhere, few to scattered mid-high level clouds, with most development in the afternoons. * Winds will be light and variable, turning westerly with peak gusts at terminal sites reaching 10-20 kts in the afternoon, in absence of any thunderstorm outflow winds. An uptick in WSW winds should be expected Monday afternoon and evening, with gusts reaching 15- 25 kts. -Dawn && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

736 FXUS66 KSTO 152035 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 135 PM PDT Sat Aug 15 2026 .KEY MESSAGES... - Cooler than normal temperatures, mild weather, and drying conditions continue this weekend into next week && .DISCUSSION... Satellite has clear skies over Interior California this afternoon, with temperatures in the 70s and 80s. We are expecting highs to reach into the upper 80s to lower 90s today, with cooler conditions within the higher terrain. Winds remain light, with occasional breezy winds within the Delta, northern San Joaquin Valley, and southern Sacramento Valley this evening. This will help cool temperatures off quickly this evening and overnight. Clouds will move back in through the Delta and spread through the southern Sacramento Valley and northern San Joaquin Valley overnight into tomorrow morning. This brings overcast to broken clouds and lower ceilings. Once the sun rises tomorrow clouds will start to mix out and temperatures climb. Temperatures will be around seasonal averages Sunday into the week ahead, with a few days slightly above average. We will continue this dry and mild weather pattern through the week, with afternoon humidity conditions in the 30-50 percent range across the Valley, outside a pocket of drier conditions over the northern Sacramento Valley. As we approach next weekend, models start to diverge on a solution as they try to handle the breakdown of the ridge over the SW United States. Breakdown of the ridge would allow for upper level systems to translate across the area, while a stagnant ridge would continue our dry conditions. && .AVIATION... VFR conditions prevail through the evening hours, with potential MVFR conditions 6z through 16z for the Sacramento Sites. This is due in part to the low stratus developing within the Delta pushing into the Sacramento metro later this evening and through the mid morning hours. This would bring 1000-3000 foot ceilings at times, with a BKN to OVC cloud deck. Other sites would see SCT to FEW clouds around 5000 feet. Otherwise, during this afternoon and evening a few gusts to 20kts will be possible for RDD and RBL. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$

467 FXUS65 KMSO 151845 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1245 PM MDT Sat Aug 15 2026 .DISCUSSION... KEY MESSAGES: - Chances for thunderstorms this afternoon for north-central Idaho, and west-central and southwest Montana. About 10% chance for storms to become severe. - Shower and thunderstorm activity will continue each afternoon through early next week. - Warming and drying latter part of next week under a ridge of high pressure. Southwesterly flow aloft will bring moisture into the Northern Rockies this afternoon. The moisture feed will coincide with a shortwave disturbance moving southwest to northeast over north- central Idaho into western Montana this afternoon and evening. Model soundings indicate enough instability to fuel thunderstorm development in the aforementioned areas. High resolution models show storms tracking with the shortwave, southwest to northeast along approximately U.S. Highway 12. Primary threats from thunderstorms will be small hail, gusty outflow winds of about 40-50 mph, heavy rain, and frequent lightning. There is about a 10 percent chance that storms become severe, meaning one-inch diameter hail and gusts of 50-60 mph. Upper level flow transitions to westerly on Sunday as a broad ridge of high pressure builds over the western U.S. The moisture feed stays uninterrupted, though, and will continue to support some thunderstorm activity in the afternoon. As next week progresses, a trough of low pressure amplifying over the eastern Pacific will bring southwesterly flow aloft to the Northern Rockies. This setup will keep afternoon thunderstorms in the forecast for the first part of the work week. High pressure coinciding with a much drier airmass will move back in for the latter part of the week. && .AVIATION...Fair weather early today will transition to more unsettled weather later this afternoon and evening in the form of thunderstorms. Storms will move from southwest to northeast, staring out in the vicinity of KSMN by about 15/2100Z. Primary threats from thunderstorms will be erratic, gusty winds of about 35-45 knots, heavy rain dropping visibility to about 4 SM, small hail, and frequent lightning. Storms will have about a 10 percent chance of becoming severe (damaging hail and gusts of 45-55 knots). Fog will be an issue on Sunday morning in areas that receive heavy rain tonight. There`s not enough confidence this afternoon for fog to include in 15/1800Z TAFs. Sunday afternoon will be similar to today as far as convection. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

806 FXUS65 KBOI 152334 AFDBOI Area Forecast Discussion National Weather Service Boise ID 534 PM MDT Sat Aug 15 2026 .UPDATE...Updated aviation discussion. && .KEY MESSAGES... - Fire weather risk continues due to thunderstorm activity today. - Thunderstorms could bring outflow winds up to 50 mph. In addition, heavy rain may also increase the risk for flash flooding, especially for vulnerable burn scars today. - Temperatures near normal through Tuesday, then a few degrees of warming expected by late week. && .SHORT TERM /Through Monday Night/... Issued 208 PM MDT SAT AUG 15 2026 Strong thunderstorms are continuing to develop across the area bringing heavy rain, small hail and gusty outflow winds to 50 mph. Despite the storms producing rainfall, lightning fire starts are still a risk especially across the lower terrain. High confidence (40% chance) in thunderstorms moving through the Treasure Valley between 3 PM and 6 PM bringing brief heavy rain, lightning and wind gusts up to 50 mph. Increased risk for flash flooding on the recent burn scars especially the Wapiti remains elevated through this evening. Please monitor the latest weather information if you live or are traveling near the large burn scars. Convective activity will taper off late tonight as diurnal cooling takes over and the primary shortwave exits to the northeast. On Sunday, an upper level ridge builds over the Great Basin, initiating an overall drying and warming trend. Moisture will be significantly limited compared to Saturday, though leftover instability will keep a slight chance (15 to 25 percent) of afternoon showers and thunderstorms over the higher terrain of central and south-central Idaho. High temperatures on Sunday will rebound to around 2 to 5 degrees above normal across the lower valleys. By Monday, residual monsoonal moisture around the western periphery of the ridge will lead to an increase in mid-level cloud cover and an expanding threat of afternoon and evening showers and thunderstorms. The best coverage on Monday will be focused over the higher terrain of northeast Oregon and central/south-central Idaho, though isolated storms cannot be ruled out for lower elevation valleys. Gusty erratic winds and localized heavy downpours will once again be the main threats with storm development on Monday. Temperatures Monday night will remain mild, staying in the upper 50s and 60s for low elevations. && .LONG TERM /Tuesday through Saturday/... Issued 208 PM MDT SAT AUG 15 2026 An upper-level shortwave trough will continue to move east through the Pacific Northwest and Northern Rockies Tuesday and early Wednesday. Shower and thunderstorm chances will be limited to the higher terrain of central Idaho as this passes through. This disturbance will suppress the upper-level ridge building in the Great Basin on these days, however Wednesday afternoon onward the ridge will amplify over the area. As the Desert Southwest ridge builds, southwesterly flow aloft will overspread the region, increasing temperatures and moisture gradually late week. Additionally, models agree on a Pacific low pressure system slowly moving onshore late week going into the weekend. This pattern will support the influx of monsoonal moisture once again, with shower and thunderstorm chances increasing by Friday and further Saturday. && .AVIATION /00Z Sunday through Monday/... Issued 528 PM MDT SAT AUG 15 2026 Scattered showers and thunderstorms through the late evening, especially north and east of the Snake Plain and through the Magic Valley of Idaho. Heavy rainfall, small hail, and wind gusts to 40-45 mph with the strongest storms. Brief reductions in visibility in blowing dust possible as well this evening. Surface winds variable around 10 kt, except vrb 30g40 kt near thunderstorms. Light diurnal winds overnight, favoring an ESE direction. Winds aloft at 10kft: SW 10-20 kt. KBOI...Showers moving to the northeast of the terminal by 01Z, with lingering gust front winds around 20-25 kt. Drying with diurnal SE winds developing this evening less than 10 kt. Sunday Outlook...VFR area-wide with isolated showers/thunderstorms across central/south-central Idaho in the afternoon and evening. Brief MVFR/IFR possible along with gusty winds near thunderstorms. Winds less than 10 kt elsewhere, along with areas of smoke near KBKE/KBNO. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Red Flag Warning until 9 PM MDT this evening for IDZ400-420- 423-424-426. Flash Flood Watch until 9 PM MDT this evening for IDZ013. OR...Red Flag Warning until 9 PM MDT /8 PM PDT/ this evening for ORZ672>675. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise AVIATION.....MC SHORT TERM...JDS LONG TERM....CH

059 FXUS65 KLKN 151617 AFDLKN Area Forecast Discussion National Weather Service Elko NV 917 AM PDT Sat Aug 15 2026 .KEY MESSAGES... * A few strong thunderstorms are possible in Eastern Nevada this afternoon into this evening * Marginal risk of excessive rainfall in Southern White Pine and Eastern Nye Counties this afternoon into this evening * Elevated fire weather conditions in Humboldt County Monday * Warming trend Sunday through Thursday && .DISCUSSION... (This afternoon through Friday) WEATHER PATTERN OVERVIEW: An upper-level area of high pressure will remain over the Southeastern United States today. Southerly flow should keep monsoonal moisture streaming northward into Eastern Nevada today, resulting in isolated to scattered thunderstorms this afternoon into this evening. A few of these thunderstorms could be strong. The primary thunderstorm hazards will be erratic wind gusts near 50 mph and dangerous cloud to ground lightning strikes. There is a marginal risk (5-15%) of excessive rainfall in Southern White Pine and Eastern Nye Counties this afternoon into this evening. Heavy rainfall may result in flooding of recent burn scars. The aforementioned anticyclone aloft will progressive retrograde westward Sunday through Friday. As a result, the flow should shift from southerly to southwesterly, pushing monsoonal moisture eastward. There is an elevated risk of wildfires in Humboldt County Monday afternoon into Monday evening due to southwest wind gusts near 25 mph and minimum relative humidity values as low as 12 percent. A warming trend is expected Sunday through Thursday. By Thursday afternoon, high temperatures across Northern and Central Nevada will be two to four degrees above normal for this time of year. High temperatures will remain above seasonal values Friday. Here are probabilities of maximum temperatures of 90 degrees or higher for select locations in Northern and Central Nevada on Thursday, August 20th, 2026: Battle Mountain - 96% Elko - 95% Winnemucca - 95% West Wendover - 95% Carlin - 95% Tonopah - 90% Wells - 90% Spring Creek - 85% Eureka - 85% Ely - 70% FORECAST CONFIDENCE & DEVIATIONS: High forecast confidence regarding the possibility of a few strong thunderstorms in Eastern Nevada this afternoon into this evening. Moderate forecast confidence in a marginal risk of excessive rainfall in Southern White Pine and Eastern Nye Counties this afternoon into this evening. Moderate forecast confidence regarding a warming trend Sunday through Thursday. Low forecast confidence in elevated fire weather conditions in Humboldt County Monday. No deviations from the NBM model output. && .AVIATION... VFR conditions will prevail at all terminals through at least the next 24 hours. Thunderstorms are expected in the vicinity of KEKO and KENV this afternoon into this evening. Direct thunderstorm impact cannot be ruled out. && .FIRE WEATHER... A few strong thunderstorms are possible in Eastern Nevada this afternoon into this evening. The primary thunderstorm hazards will be erratic wind gusts near 50 mph and dangerous cloud to ground lightning strikes. Elevated fire weather conditions are expected in Humboldt County Monday due to southwest wind gusts near 25 mph and minimum relative humidity values as low as 12 percent. && .LKN Watches/Warnings/Advisories... None. && $$ 87