ZSE Aviation Forecast Discussions

080 FXUS66 KSEW 031622 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 922 AM PDT Mon Aug 3 2026 .SYNOPSIS... An upper level ridge will build offshore today and tonight then move inland Tuesday and Wednesday. Thermally induced surface trough developing over the area tonight will remain in place through at least Wednesday night creating northerly flow in the lower levels. This will pull some smoke over Western Washington. The ridge will shift eastward later Thursday into Friday. Increasing low level onshore flow at the end of the week with cooler temperatures and less smoke. && .SHORT TERM /TODAY THROUGH WEDNESDAY/... Hazy skies this morning; satellite imagery shows smoke aloft from the fires in Eastern Washington moving across Western Washington. Chilly morning for the first week of August with Bremerton and Olympia in the 40s. Most of the remainder of the area in the lower to mid 50s. Upper level ridge building over Western Washington today with the ridge axis offshore. Northerly flow aloft last night pulled some upper level smoke down over the area ( you could see it at sunset ) but with the flow aloft becoming more northwesterly with the ridge building smoke in the upper levels will be kept at a minimum. Patchy low clouds and fog will dissipate early with sunny skies. Highs warming into the 70s and lower 80s. Upper level ridge continuing to build tonight and Tuesday with the ridge axis drifting towards the Pacific Northwest. Thermally induced surface trough developing along the coast tonight turning the low level flow northeasterly. This will most likely pull low level smoke from the fires in Eastern Washington into Western Washington by Tuesday morning. Smoke will remain over the area during the day. The transition to offshore flow in the lower levels warming high temperatures into the 80s and lower 90s. Lows Monday night in the 50s. HeatRisk moving into the moderate category for most locations away from the immediate coast. Upper level ridge axis moving over Western Washington later Tuesday night into Wednesday with the thermally induced surface trough over the area. Low level northeasterly flow will keep low level smoke moving into Western Washington. Highs in the 80s to mid 90s. Lows in the mid 50s to lower 60s, cool enough to prevent most of the area from major HeatRisk. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... Models showing good consistency for the latter half of the week into the weekend. Upper level ridge axis over the area Wednesday night moving east Thursday and Friday. Thermally induced surface trough moves over the interior Thursday. Afternoon seabreezes developing along the coast cooling high temperatures into the lower to mid 70s. One more hot day over the interior with highs similar to Wednesday, 80s to mid 90s. Moderate HeatRisk with a 20-40 percent chance of major HeatRisk Central and Southern Puget Sound and Cascade foothills. Increasing low level onshore flow Thursday night into Friday with the ridge axis well to the east and the thermal induced trough moving east of the Cascades. Low level onshore flow will bring cooler temperatures and also push the low level smoke out of the region. Highs in the mid 70s to mid 80s inland and upper 60s along the coast. Lows in the 50s and lower 60s. Weak upper level trough settling over the area for the weekend with varying degrees of low level onshore flow. Morning clouds each day will give way to afternoon sunshine. Highs in the 70s and lower 80s. Lows in the 50s. Felton && .AVIATION... Northwest flow aloft throughout the TAF period as an upper-ridge axis sits offshore. Low-level flow has switched northerly - ushering in drier air and leading to mostly clear skies (VFR) this morning. VFR remaining throughout the day Monday into Tuesday as well. Elevated smoke from region fires today. Smoke will become more surface based on Tuesday and bring the chance for visibility restrictions. As to how much visibility will decrease, it is uncertain at this time. KSEA...VFR throughout the TAF period. Elevated smoke will increase today before becoming more surface-based into Tuesday. Can`t rule out the chance for vis restrictions. NE surface winds 6-8 kt this morning, increasing out of the N-NW this afternoon 8-12 kt with gusts near 20 kt. Winds out of the NE 5-8 kt overnight into Tuesday. && .MARINE... A strong surface high pressure will continue to remain offshore throughout midweek as a thermally induced low pressure expands northward along the interior coast. Winds over the waters will continue to generally remain under small craft advisory levels. The exception being, with the aforementioned presence of the thermal trough over Western Washington, this could allow winds over the outer coastal waters to approach low end advisory levels this afternoon briefly and also, Tuesday afternoon mainly in the southern inner coaster water zone. The surface trough will move eastward Thursday and Thursday night for increased onshore flow across the region, along with potential headlines for westerlies in the Strait of Juan De Fuca. Coastal seas generally 4 to 6 feet through the first half of the week. Seas look to gradually increase 6 to 8 feet during the second half of the week. Mazurkiewicz && .FIRE WEATHER... No changes as far as fire weather is concerned. Warming trend beginning today peaking Thursday. Very low daytime RH values throughout the CWA Tuesday through Thursday. The Cascades, Cascade valleys, the adjacent lowlands of the Chehalis River Valley and the south Puget Sound area will be of particular concern. Minimum RH values each of those afternoons are expected to slip into the teens. Wednesday and Thursday will be of particular concern as minimum RH values could get as low as the low teens to upper single digits. No significant winds or instability expected during this time frame, so Red Flag criteria will most likely not be met. Even without a red flag warning, with RHs this low, any wind will contribute to fire spread and as such, maximum caution is emphasized. Friday and beyond will see a much more significant rebound in daytime RH values with low level onshore flow. Felton && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$

443 FXUS66 KPQR 032144 AFDPQR Area Forecast Discussion National Weather Service Portland OR 244 PM PDT Mon Aug 3 2026 .SYNOPSIS...Offshore flow will bring hot, dry, and smokey conditions to northwest OR and southwest WA Tuesday through Thursday. High temperatures for most inland valley locations peak in the mid to upper 90s Tuesday to Thursday, resulting in a widespread Moderate to locally Major HeatRisk impacts. Temperatures begin to trend cooler Friday into the weekend with the return of onshore flow, which will also push any lingering wildfire smoke and haze east of the Cascades. Fire weather concerns remain in the forecast through Wednesday in the western Columbia River Gorge and portions of the Willamette Valley. && .DISCUSSION...Now through Sunday night...Satellite imagery from Monday afternoon showed widespread wildfire smoke and haze spreading over southwest Washington and much of northwest Oregon to the north of a line extending from Newport to Salem to Timothy Lake in response to increasing offshore winds. Smoke has mixed down to the surface over some inland areas, lowering surface visibilities down to 5-9 miles over the greater Portland/Vancouver metro and central/northern Willamette Valley. Visibilities appear even lower over portions of the Mt. Hood National Forest, north OR Cascade foothills, and the western Columbia River Gorge due to a more concentrated smoke plume blowing westward from the Grasshopper Fire. As a result of this smoke, air quality has begun to degrade in the aforementioned areas. The Oregon Department of Environmental Quality (DEQ) and the Southwest Clean Air Agency have issued Air Quality Alerts for portions of southwest WA and northwest OR, including the Portland/Vancouver metro. For updates regarding the air quality forecast and any Air Quality Advisories that are in effect, please visit the Oregon Smoke Blog at oregonsmoke.org and the Washington Smoke Blog at wasmoke.blogspot.com. Smoke and haze will likely continue impacting the area through at least Wednesday or Thursday before onshore flow returns and helps clear smoke out of the area from west to east late Thursday into Friday. Until then, offshore flow and upper level ridging will not only maintain smoke and haze but will also bring heat and fire weather concerns. For fire weather concerns, please refer to the fire weather discussion below. For heat, model guidance remains in good agreement for highs in the mid to upper 90s on Tuesday and Wednesday, and somewhere in the 90s on Thursday. However, the impacts of wildfire smoke on temperatures needs to be taken into account, as areas with dense wildfire smoke will see high temperatures limited by several degrees. The RRFS model, which does account for wildfire smoke, suggests highs will be most limited over the northern Willamette Valley, Columbia River Gorge, Portland/Vancouver metro and Mt. Hood National Forest on Tuesday with highs only in the low to mid 90s rather than upper 90s. Meanwhile, smoke impacts on temperatures over the rest of southwest WA and northwest OR are minimal. On Wednesday, the RRFS model suggests little to no impacts on temperatures due to a more dispersed and thinner smoke layer. Regardless of the exact outcome, it will still be hot enough to bring an increased risk of heat-related illnesses. As such, various Heat Advisories remain in effect for most inland valleys beginning Tuesday afternoon. In areas with Air Quality Advisories in effect, it is recommended to keep windows and door shut to prevent smoke from going indoors. However, those without air conditioning who are counting on opening their windows at night to help cool down will have less options. In this scenario, something as simple as a large box fan with a damp towel draped over the front of it can be surprisingly effective given the dry airmass in place. Heading into Friday and next weekend, model ensemble guidance continues to suggest onshore flow will strengthen with temperatures trending cooler each day. This will scour out any lingering smoke and haze in the area, bring an end to heat concerns along with decreasing fire weather concerns. -23 && .AVIATION...Through 18Z Tue...Smoke aloft between 5000-9000 ft with easterly flow. Thermal trough forms tonight causing winds to shift to the north, especially along the coast and the Willamette Valley. Gusts upwards of 25-30 kt along the coast and south of KSLE. Cannot rule out gusts up to 25 kt around KSLE and KUAO this afternoon, but not expected to be as widespread. For the easterly flow, some observations through the Columbia River Gorge are around 25 kt but those should ease through the day. Overnight, the smoke aloft will settle towards the surface as winds ease. This smoke will cause slight reductions to visibility down to 6SM north of Salem. However, we cannot rule out denser smoke around K4S2 and smaller runways west of the Grasshopper Fire, or any new fires that may ignite today. KPDX AND APPROACHES...VFR conditions are expected to continue locally. Northerly winds around 5-10 knots this morning increase late morning/midday with occasional gusts around 20 knots possible through the afternoon into the early evening. Smoke may settle overnight reducing VIS to around 6SM. Confidence is around 35-50% for this occurring. -27/99 && .MARINE...An upper-level ridge of high pressure building off the coast continues to drive northerly winds across the waters today with gusts greater than 21 kt being reported on area buoys. The northern buoys have struggled to see the rises which isn`t uncommon for a northerly wind, but they are still hovering right around 21 kt for gusts. A Small Craft Advisory remains in effect for all of the water into the middle of the week which, if wind waves remain elevated, could extend further. The Columbia River Bar is included in these Small Crafts due to wind. There is a slight chance (15-30%) that the bar could see a return of the wind on Tuesday evening, but right now the length of time would be for just a few hours between 1500-2000. They would also be marginal and impact the main entrance to the bar and not the interior portions of PZZ210. Starting Thursday, flow becomes zonal and winds will shift slightly to the northwest. Therefore will see wind waves shift slightly. Overall wind speeds will decrease but seas will stay relatively similar around 6 to 8 ft at 10 seconds and being mostly wind wave driven. -27 && .FIRE WEATHER...Today through Thursday...Critical fire weather conditions are expected this afternoon and evening over the central/southern Willamette Valley mainly to the south of Salem this afternoon and evening due to breezy north winds with gusts up to approximately 25 mph combined with low relative humidity values down to 20-25%. A few max gusts upwards of 28 mph are possible. This means any new or existing fires in this area could exhibit rapid fire spread. As such, a Red Flag Warning remains in effect for fire weather zone 685. Although wind speeds are not forecast to be quite as strong to the north of Salem, conditions will still be dry and breezy enough for elevated fire weather concerns with conditions approaching red flag warning criteria. We have a developing thermally induced surface trough causing these winds as it lifts northward into the region. While winds at the surface have a large northerly component today, easterly winds will be developing aloft around 3000-6000 ft this morning. These easterly winds will bring in drier air from east of the Cascades and the downsloping action will increase compressional warming and drying in the lower elevations and in the Willamette Valley. Combine this with daytime heating and a deep layer of dry air, we will see relative humidity drop within the interior lowlands as low as 18-25%. Tonight into Tuesday, the surface thermal trough is expected to amplify while the axis of this feature shifts towards the Oregon coast. This will further increase easterly winds in the Columbia River Gorge and Cascades, in addition to a lowering subsidence inversion with sharp overnight thermal belts/poor overnight humidity recoveries, particularly in the Cascades. Easterly winds on Tuesday are expected to be strongest in the western Gorge with gusts up to 30-40 mph in the most wind-prone locations. Given the low relative humidity values in place at that time, critical fire weather conditions capable of rapid fire spread will be possible. Conditions then remain dry and windy in the western Gorge as easterly winds continue Tuesday night through Wednesday evening. Winds in the Gorge will be strongest Tuesday morning through early Tuesday afternoon, and again Tuesday night through early Wednesday afternoon. Relative humidity values will be lowest Tuesday afternoon and Wednesday afternoon, down to 15-20%. Poor overnight humidity recoveries are expected Tuesday night with maximum relative humidity values ranging between 35-45%. Therefore, a Red Flag Warning has been issued for the western Gorge, fire weather zone 636, from 11 AM PDT Tuesday through 8 PM PDT Wednesday. The rest of the Cascades will have relatively weaker easterly winds with gusts generally in the 15-25 mph range. One exception would be on exposed ridgetops and west-east oriented valleys where slightly higher wind gusts are likely. Nevertheless, elevated fire weather concerns still exist in these areas, as well as in the Portland metro and Willamette Valley where NNE to NE winds are expected to gust up to approximately 15-20 mph in the afternoon. Again expect poor ridgetop relative humidity recoveries in the Cascades and Roast Range Tuesday night. Fire weather concerns decrease more considerably by Thursday, with one potential exception. Thursday is when we transition to onshore flow, which will bring breezy westerly winds in the central Gorge and Hood River area. Given conditions will still be dry, elevated fire weather concerns will remain in place. -23/99 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...Heat Advisory from noon Tuesday to 11 PM PDT Wednesday for ORZ104-105-108>118. Red Flag Warning until 8 PM PDT this evening for ORZ685. WA...Heat Advisory from noon Tuesday to 11 PM PDT Wednesday for WAZ204>208. Red Flag Warning from 11 AM Tuesday to 8 PM PDT Wednesday for WAZ636. PZ...Small Craft Advisory until 1 AM PDT Tuesday for PZZ210. Small Craft Advisory until 5 AM PDT Wednesday for PZZ251>253- 271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

759 FXUS66 KMFR 031230 AFDMFR Area Forecast Discussion National Weather Service Medford OR 529 AM PDT Mon Aug 3 2026 ...Updated AVIATION discussion for 12Z TAFs... .KEY MESSAGES... * Daytime highs increase today and Tuesday, bringing temperatures 5 to 15 degrees above seasonal norms across the area. These temperatures present Moderate to Major levels of HeatRisk. * Changes to the surface wind pattern may bring smoke from area wildfires over the area. * Cooling is possible to end the week and into the weekend. * Thunderstorm signals continue to be absent through the forecast period. && .DISCUSSION...A warming trend starts for most of the CWA today as high pressure takes control of area conditions. Daytime highs west of the Cascades and into northern Klamath County will increase by 5 to 10 degrees from Sunday. Other areas farther east will see similar temperatures continue today. Warming continues on Tuesday as a ridge axis moves over the area. In general, temperatures on Tuesday look to be 5 to 15 degrees above normal for most areas. The Oregon coast will be in the mid 70s to low 80s. Temperatures increase heading inland, with the Umpqua Valley expected to be in the high 90s to the low triple digits. Other west side valleys will be in the 100-110 degrees range. Valleys and basins to the east will be in the high 80s to mid 90s this afternoon. For west side areas, these general temperatures are expected through Thursday. Areas east of the Cascades warm to the mid to high 90s on Wednesday, with those temperatures continuing into Friday. In addition to these elevated daytime highs, overnight lows will also rise 5 to 10 degrees above normal through the heat wave. Models have narrowed their forecast ranges somewhat. Using Medford as an example, chances to reach 110 degrees are absent from GFS, ECMWF, and NBM guidance. These expected conditions will bring Moderate to Major levels of HeatRisk to west side valleys, and generally moderate HeatRisk to east side valleys and basins. At Major levels, anyone without cooling or hydration may experience heat-related illnesses. These conditions support a Heat Advisory already in place for west side valleys, while east side areas may see Heat Advisories for their warmer period starting Wednesday. Although Major levels and associated warning products are currently limited to valley floors, please do not underestimate the heat in any area. See NPWMFR for more information. A change to high pressure looks to bring surface winds from the north during the day and from the east overnight. With ongoing wildfires to the north and northeast, this change in winds could bring smoke concerns back to the ares. For this morning, smoke generally looks to be slight to moderate east of the Cascades and slight to the west. Smoke models show increased concentrations moving across the area from north to south this afternoon into tonight, then settling as breezes decrease. While significant daytime cooling is unlikely, the combination of warm to hot conditions and poor air quality may be especially uncomfortable for sensitive individuals. Additionally, dry conditions and gusty wind patterns are bringing significant fire weather concerns through the heat wave. Please see the FIRE WEATHER discussion below or RFWMFR for more information. In short, especially warm and dry conditions can further dry vegetation out and periods of gusty winds can carry ignited material. Please consider extra caution to minimize any activity that can ignite a fire. More seasonable temperatures are possible to end the week and into the weekend as the ridge axis shifts out of the area, with deterministic imagery showing an upper trough developing along the Pacific coast by Sunday. While atmospheric instability and thunderstorms are sometimes a concern after heat waves, current modeling shows that atmospheric moisture is limited as southwest flow aloft would continue to bring dry air. -TAD && .AVIATION...03/12Z TAFs...Stable atmospheric conditions are allowing VFR levels to generally persist across northern Oregon and southern California through the TAF period. A thermal trough will bring gusty winds along the Oregon coast and into the Umpqua Valley this afternoon and evening before winds ease into the night. Surface winds look to move wildfire smoke into the area this afternoon and evening, which may periodically impact visibilities at area terminals. -TAD && .MARINE...Updated 300 AM PDT Monday, August 3, 2026...Gusty northerly winds continue across area waters today. Gale force winds and very steep seas remain south of Cape Blanco through tonight, with steep seas to the north. Winds drop out of gale ranges on Tuesday, but very steep seas to the south and steep seas to the north persist. By Wednesday, southern waters improve slightly. Areas of steep seas look to continue through the end of the week. -TAD && .FIRE WEATHER...Updated 100 PM PDT Sunday, August 2, 2026... Upper level ridging will build in quickly along with a thermal trough at the surface, resulting in a very warm and very dry week ahead. The strengthening thermal trough in northern California and SW Oregon will result in a period of offshore N-NE winds for the coast ranges and mountains of western Siskiyou County tonight. For early this morning, model 925-850 winds are in the 25-30kt range. This should result in some gusty winds (25-30 mph) at the usual locations in vicinity of the thermal belts (perhaps gusts to 40 mph in the windiest spots). Observations from area RAWs do show gusty winds continuing, especially at higher elevations. Aligning with the Chetco River, these winds will descend resulting in compressional warming/drying all the way to the coast near Brookings (FWZ 618) on Monday. Look for elevated fire risk there and into FWZ 619 with highs in the 80s, low humidity and gusty NE breezes. The N-NE breezes could also align with the Illinois Valley (FWZ 620) and funnel through the Rogue Valley (FWZ622) this afternoon/early evening, with critical conditions likely. For tonight, poor RH recoveries are expected across all of SW Oregon and northern California upper slopes/ridges. Some guidance is showing RH only recovering into the low 20s (upper teens?!) Tuesday through Thursday, while daytime minimum humidities could easily drop into the single digit percentages. Fortunately, winds will diminish some form the previous day. With these hot, dry, and windy conditions continuing Monday into Tuesday with little improvement overnight, a Red Flag has been issued for the Illinois and Rogue valleys, as well as the Siskiyous and southern Oregon Cascades, beginning Monday afternoon and continuing into Tuesday evening. Current model guidance shows only minimal improvement in wind and humidity Tuesday night into Wednesday, so the Red Flag may need to be extended further into the week. Outside of the Red Flag Warning area, conditions will still be hot, dry, and windy, with conditions approaching critical values at times. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning from 2 PM this afternoon to 9 PM PDT Tuesday for ORZ620>623. Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday for ORZ023-024-026. CA...Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday for CAZ080. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this evening for PZZ356. Hazardous Seas Warning from 11 PM this evening to 9 PM PDT Tuesday for PZZ356-376. Small Craft Advisory until 9 PM PDT Tuesday for PZZ350-370. Gale Warning until 11 PM PDT this evening for PZZ356-376. && $$ TAD/TAD/TAD

223 FXUS66 KEKA 030747 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1247 AM PDT Mon Aug 3 2026 .KEY MESSAGES... * Hot temperatures will bring a moderate to major heat risk for portions of the area today and Tuesday. Moderate heat risk continues through the week. * Overnight northeasterly winds and poor RH recovery will increase fire danger mainly in Del Norte, Humboldt and Trinity counties tonight and to a lesser extent Tuesday. * Coastal warmup through Tuesday with offshore flow. && .SYNOPSIS...Breezy northeast winds are keeping coastal areas mostly clear and will help warm temperatures above normal today. High pressure continues to build in is expected to bring hot temperatures to the inland valleys (warming to near 105). Some coastal clouds are expected to return starting Tuesday and expanding Wednesday through late in the week. && .DISCUSSION...High pressure is building into the area as an upper level trough moves off to the east in the Pacific Northwest. This is expected to bring hot temperatures across the interior valleys. Some of the warmer valleys are expected to range from 105 to 110. Offshore flow is also expected to bring warm temperatures a bit closer to the coast today with highs in the 70s. Tonight lows are expected to generally drop into the low to mid 60s in the valleys, but the ridges are expected to see lows in the 70s. Tuesday the upper level ridge starts to move overhead and this is expected to bring a few subtle changes. In general this is expected to bring lighter winds. This may allow a southerly wind reversal start to bringing stratus north to the Mendocino coast. This may also bring some southerly winds to Ukiah which could keep temperatures a few degrees cooler in Mendocino county. The lighter winds may allow the coast north of Cape Mendocino to warm up with the combination of the lighter winds at the surface and the offshore flow aloft. This has the potential to bring high temperatures in the mid to upper 70s. Farther south it looks like the southerly winds may start to bring stratus northward. Wednesday through Friday the upper level ridge very slowly moves off to the east. This will likely bring a return of stratus to much of the coast, although afternoon clearing is likely most afternoons. Hot temperatures are expected to continue with most valleys continuing to see highs around 100. Some cooling is finally expected for the weekend. MKK && .AVIATION...Mostly clear skies are in place across the area this morning. A few local areas of ground fog are possible around sunrise at the coastal TAF sites, but if these occur they should be localized and shortlived. This afternoon breezy winds are expected once again, although the are expected to be lighter than on Sunday afternoon. Monday night into Tuesday morning, the offshore flow is weaker and this may allow some stratus to start to develop along the Humboldt coast. The Mendocino coast is expected to start seeing a southerly surge of stratus at some point early Tuesday morning. MKK && .MARINE...The stronger winds have started to push off the coast in the waters south of Cape Mendocino. The gale warning has expired and have issued a hazardous seas warning through later this morning to highlight the lingering large seas. The gales are expected to continue in the outer waters through this evening, although there is lower confidence on how widespread the coverage will be in the southern waters. Tonight and Tuesday the winds and seas continue to diminish as the high pressure gradually pushes the winds farther off the coast. Tuesday morning the weakening northerly winds are expected allow a southerly surge of winds and clouds or fog to move north. This may increase to around 10 to 15 kt along the Mendocino coast Tuesday afternoon. Tuesday night and Wednesday the northerly winds continue to weaken and allow some light southerly winds to spread across more of the area. These light winds and seas are generally expected to continue through Thursday morning. Thursday afternoon through Friday and into the weekend are expected to increasing northerly winds once again. There is the potential for gales again over the weekend, but confidence is low on this at this point. MKK && .FIRE WEATHER...This morning northeast winds have start to increase at the higher elevations of Del norte county. Gusts of 30 to 40 mph are are possible at the ridges and possibly the northeast aligned drainages. Currently it looks like the dry air is only at the highest elevations, but this could still lower this morning. The current forecast is now showing a fairly big area of eastern Del Norte county with recoveries of only 30 to 40 percent. This will also impact the interior ridges of Humboldt, and Trinity counties to a lesser extent. Afternoon RH will trend much lower across the interior to the low teens and likely some single digits by Monday afternoon and then remaining dry through much of the week. Afternoon west- northwesterly gusty winds can be expected each afternoon. These winds are expected to be more typical for the summer afternoons only lasting a few hours and not as strong as over the weekend. Smoke discussion. This afternoon the HRRR smoke model is showing some smoke moving into eastern Trinity county, although this is expected to be fairly shortlived. In Del Norte county, the northeasterly winds are expected to return tonight into Tuesday, although they are not expected to be be as strong. However with the more persistent northeasterly winds aloft this may bring some smoke out to the coast. The HRRR and RRFS models both show some smoke make its way out to coastal Del Norte and then south into Humboldt county. Confidence is low on this, but it will need to be watched. MKK && .EKA WATCHES/WARNINGS/ADVISORIES... CA... Heat Advisory from 11 AM to 11 PM PDT Tuesday for CAZ102. Heat Advisory from 11 AM Tuesday to 9 PM PDT Wednesday for CAZ105-106. Heat Advisory from 11 AM Tuesday to 11 PM PDT Thursday for CAZ108-116-117. Heat Advisory from 11 AM Monday to 11 PM PDT Tuesday for CAZ110-111-113-114-118>120. NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning until 3 AM PDT Monday for PZZ450. Hazardous Seas Warning until 9 AM PDT Monday for PZZ455. Gale Warning until 3 AM PDT Tuesday for PZZ470-475. && $$ 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

916 FXUS66 KMTR 032009 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 109 PM PDT Mon Aug 3 2026 ...New SHORT TERM, LONG TERM, MARINE... .KEY MESSAGES... Updated at 1155 PM PDT Sun Aug 2 2026 - Moderate HeatRisk in the interior through Tuesday, becoming patchy midweek - Near critical fire weather threat across the interior North and East Bays, and the Diablo and Santa Lucia ranges through Monday with elevated fire weather threat through the week - Widespread Moderate HeatRisk looks to return for the end of the work week. && .SHORT TERM... Issued at 1255 PM PDT Mon Aug 3 2026 (This evening through Tuesday night) Nearterm:The southerly surge continues to inch its way northward along the coast and finally made it past Pt Reyes. The surge has really taken a bit out of temperatures along the immediate coast this afternoon. 24 hr trends show many locations along the coastline are running cooler than Sunday, which isn`t surprising with nearby clouds. On the flip side, head inland and away from the surge influence and temps are soaring into the 90s and lower 100s. As such, Heat Adv remains in effect through this evening for Interior North Mts and Interior East/South Bays. Tonight through Tuesday night: The surge will become less of a surge and more just onshore with more stratus. Moderate marine layer stratus coverage for inland areas tonight. This stratus will bring some relief and better RH, but above the shall layer will remain mild and dry. Interesting set up for Tuesday as the upper level pattern shows a slight rebound of the ridge, but lower surface levels keep the southerly/onshore flow. Pretty hard to bet again stratus and cooler SST along the coast. As such, temperatures for Tuesday will be within a few degrees of Monday, but on the cooler side. Just enough to knock down HeatRisk values to Moderate with little to no Major. Tuesday night will see even more stratus coverage with a slight deepening. One final concern for the short term will be smoke/haze. Ample fire activity across OR/WA will push some smoke over the coastal waters. Longer range RRFS actually brings some smoke/haze to the coastal waters late Tuesday into Wednesday. && .LONG TERM... Issued at 1255 PM PDT Mon Aug 3 2026 (Wednesday through next Sunday) Rinse and repeat for the long term, but in the other direction with a gradual warming and drying trend. Upper level high pressure that briefly flattened will rebuild over the West Coast beginning late Wednesday lasting through at least Friday. While there is a slight reprieve in temps mid-week inland heat and increasing HeatRisk return Thursday and more so Friday. In fact, some of the guidance suggest an airmass approaching 30C at 850mb. 30C is a pretty toasty airmass, which would easily yield max temps over 100 across the interior. Would also expect mild overnight lows in the hills. If this trend continues we may need another Heat Advisory. && .AVIATION... (18Z TAFS) Issued at 1133 AM PDT Mon Aug 3 2026 Current satellite imagery shows stratus receding to the coastline. Widespread VFR conditions prevail through the day as onshore winds increase to around 10-15 kt before easing into the evening. We had a bit of a disorganized southerly surge of marine stratus that not only brought IFR-LIFR ceilings to the coastline, but also south to southwesterly winds. We can anticipate another southerly surge to happen again tonight, though there is low to medium confidence on the exact arrival of marine stratus and how far inland it will perturb. Highest confidence for IFR ceilings, intermittently LIFR, at HAF and the Monterey Bay terminals. High confidence SJC and LVK will remain VFR through the TAF period. Low to medium confidence for marine stratus to reach North Bay terminals, though TAFs hint at the potential with SCT decks. Vicinity of SFO...VFR with moderate onshore breezes into the evening. Medium confidence on VFR conditions through the TAF period. As described above, there is uncertainty on whether the southerly surge of stratus will push through the Golden Gate and inland. If the stratus makes it through the Golden Gate, it is possible for IFR ceilings to reach OAK and SFO around the time of the SCT decks. Leaned more on the optimistic side for this TAF period as the surge was rather disorganized this morning and likely will be again tomorrow morning. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Onshore winds follow their usual diurnal pattern with VFR conditions prevailing. As mentioned previously, the southerly surge of marine stratus will return overnight with SW winds likely for MRY. SNS will remain more NW. Low-end IFR ceilings will impact SNS first and then MRY between 06-10Z. Winds should remain light overnight, but there is the potential for visibility impacts around 4-6SM due to coastal drizzle/fog. Ceilings may also intermittently drop down to LIFR given how compressed the marine layer will be. && .MARINE... (Tonight through next Saturday) Issued at 1215 PM PDT Mon Aug 3 2026 North to northwest winds continue to decrease from strong to fresh into the evening, becoming moderate overnight. Strong gusts persist in the far northern waters through the day before diminishing this evening. In response, rough wind driven seas continue to subside to moderate (4-7 feet) by tomorrow afternoon and prevail thereafter. && .FIRE WEATHER... Issued at 1200 PM PDT Sun Aug 2 2026 Near critical fire weather conditions are expected through Monday and after a period of elevated fire weather conditions, potentially return later in the week. Temperatures remain around 10 to 15 degrees above normal across the interior through early next week with highs in the upper 80s to 90s. No major changes to the forecasted dry conditions. Daytime humidity retention remains poor across the interior (20-30%) with humidity values dropping into the 10s across the interior Central Coast, East Bay Hills/Valleys, and the higher elevations. Portions of the interior Central Coast may see daytime humidity values drop into the single digits through the next couple of days. Overnight RH recovery remains poor at locations above 2,000 feet with values between 25 to 40% expected with some favored locations struggling to reach even 25%. This will be particularly true across the Mayacamas, highest peaks of the East Bay Hills, the Diablo Range, the Santa Cruz Mountains, the Santa Lucia and Gabilan Ranges. Nocturnal drying (rapid decrease in RH through the pre- dawn hours) may also transpire which will increase the burn period or time in which fire behavior may remain active. Energy Release Component (ERC) values are projected to climb above the the percentile across the interior Central Coast, Mid Coast to Mendocino (North Bay), and Diablo- Santa Cruz (Diablo Mountains and Santa Cruz Mountains) zones within the next two days. Diurnally breezy onshore winds are expected along the coast, mountain gaps and passes, and along the ridgelines each afternoon/evening. In addition, a burst of offshore wind is forecast tonight into Monday morning for the SF Bay Area and the North Bay, increasing the risk for nocturnal drying events especially in downslope areas. With near critically dry conditions and above normal temperatures expected, individuals across these areas are advised to avoid activities that may spark a fire. Fire crews are urged to exercise extra caution when executing any prescribed burns, especially where fuels, topography, and weather align. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory until 10 PM PDT this evening for CAZ504-510- 513>515. PZ...Small Craft Advisory until 9 PM PDT this evening for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 3 PM PDT this afternoon for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...KR LONG TERM....KR AVIATION...Navarrete MARINE...Navarrete 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

749 FXUS66 KOTX 032110 AFDOTX Area Forecast Discussion National Weather Service Spokane WA Issued by National Weather Service Seattle WA 210 PM PDT Mon Aug 3 2026 .KEY MESSAGES... - Extensive amounts of smoke will continue over the region this week, maintaining unhealthy air quality. - Temperatures steadily warm through the through the week ahead, with temperatures warming above normal by the middle of the week. - Dry conditions and breezy winds increase Friday and Saturday across portions of central Washington, bringing elevated fire weather conditions. && .SYNOPSIS... High pressure continues across the region this week, bringing steadily warmer and drier conditions each day. Wildfire smoke will bring degraded air quality for the Inland Northwest. Breezy winds increase late in the week, leading to increased fire weather conditions Friday and Saturday && .DISCUSSION... Widespread smoke remains across the region this afternoon, with a dry northwest flow pattern emerging behind the departed upper trough. High pressure then continues to build over the area through midweek. This will maintain warmer daytime temperatures and low relative humidity values each day. With winds generally from the north/northwest, expect additional rounds of smoke to impact the region from local and regional fires. Once the smoke arrives, easing winds and stronger high pressure will leave lingering issues. Air Quality Alerts have been issued by air quality agencies across central and eastern Washington, as well as north Idaho. While the current temperature forecast continues to reflect temperatures reaching well into the 90s Wednesday through Friday, the impact of the widespread smoke across the region could hold daytime temperatures a little cooler than would otherwise be expected. Looking ahead to the end of the week and into the weekend, dry air remains in place but the high pressure ridge begins to flatten out. This zonal flow and the dry air mass will bring increased potential for wind gusts around 30 mph through the Cascade gaps and around 20 mph across portions of eastern Washington Friday and Saturday. This will bring the potential for elevated to locally critical fire weather conditions. && .AVIATION... 18z TAFs: MVFR conditions have continued across many terminals this morning due to smoke from area wildfires. Pilot reports around eastern WA and north ID indicate a thicker layer around 5000 ft with scattered smoke above, though conditions remain variable as the smoke is transported. Expect continued visibility reductions in smoke for many terminals including KGEG, KSFF, KCOE, KMWH and KEAT through the period. Northerly surface winds across most terminals today, with winds easing overnight. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Moderate to high confidence in winds. Moderate confidence for smoke impacts bringing MVFR to IFR visibilities for area TAF sites. ----------------------- 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 50 85 52 90 56 95 / 0 0 0 0 0 0 Coeur d`Alene 50 84 53 89 57 94 / 0 0 0 0 0 0 Pullman 44 83 46 88 50 93 / 0 0 0 0 0 0 Lewiston 54 88 57 94 60 100 / 0 0 0 0 0 0 Colville 42 86 45 91 50 96 / 0 0 0 0 0 0 Sandpoint 45 82 48 89 52 94 / 0 0 0 0 0 0 Kellogg 49 81 52 85 55 92 / 0 0 0 0 0 0 Moses Lake 52 89 53 93 57 98 / 0 0 0 0 0 0 Wenatchee 60 89 63 94 66 99 / 0 0 0 0 0 0 Omak 54 90 57 94 61 98 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until further notice for Adams, Asotin, Chelan, Douglas, Ferry, Garfield, Grant, Lincoln, Okanogan, Pend Oreille, Spokane, Stevens, and Whitman Counties ID...Air Quality Alert until noon PDT Wednesday for Boundary, Bonner, Benewah, Clearwater, Idaho, Kootenai, Latah, Lewis, and Nez Perce, and Shoshone Counties && $$

848 FXUS66 KPDT 032147 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 247 PM PDT Mon Aug 3 2026 .KEY MESSAGES... - Elevated to locally critical fire weather conditions Tuesday - Widespread smoke and haze through at least mid-week - Widespread Moderate to locally Major HeatRisk middle to late week. && .DISCUSSION... Satellite imagery shows widespread smoke and haze across the forecast area this afternoon. Upper-level troughing has exited to the east over the Northern Great Plains, and an amplifying upper-level ridge is noted offshore in the Pacific. This pattern has set up a classic West Coast thermal trough (WCTT) to the west of the Cascades, leading to an offshore-directed pressure gradient and ample southward and westward smoke transport from the wildfires to our north in northern Washington and Canada. Wildfire smoke is expected (99 percent confidence) to persist across the region through at least mid-week as the upper-level ridge amplifies and slowly tracks eastward. Winds will remain diurnally and terrain-driven and supportive of continued advection of smoke into the region. Air quality headlines have been issued by Oregon Department of Environmental Quality, the Washington State Department of Ecology, Benton Clear Air Agency, and the Yakima Regional Clean Air Agency, valid until further notice. The ridge axis will move inland Wednesday through Friday, with increasingly hot temperatures forecast during the period. Currently, widespread Moderate to locally Major HeatRisk is forecast due to afternoon temperatures in the 95-100 degree range and lows in the 50s and 60s. That said, note that wildfire smoke inhibits efficient solar heating so afternoon temperatures may end up being several degrees cooler than currently forecast if smoke is sufficiently dense. Conversely, the dry air mass (PWATs of 0.2-0.6") should facilitate efficient nocturnal cooling, and smoke does not significantly affect nocturnal cooling. The upper-level pattern will likely change (70 percent chance) by late week, mostly likely Friday through the weekend, to a quasi-zonal pattern as ensemble clusters indicate some flavor of upper-level low or shortwave trough will track inland over British Columbia. This solution would lead to a reversal of surface pressure gradients and result in breezy to windy westerly winds through the Cascade gaps and across the Blue Mountain foothills and Columbia Basin. Wind coupled with low relative humidity in this scenario would lead to increasing fire weather concerns (see FIRE WEATHER section below). Moreover, the westerly wind represents the best chance of scouring the widespread smoke. && .AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...Variable conditions currently across sites, with IFR at KRDM, MVFR at KPDT/KYKM/KALW, and VFR conditions at KDLS/KPSC. IFR and MVFR conditions are expected to persist through the evening associated with decreased visibilities and ceilings related to smoke from nearby wildfires. Winds are expected to stay light and below 10kts for all sites through the period. 75 && .FIRE WEATHER... Elevated to locally critical fire weather conditions are forecast Tuesday as locally breezy east to northeast winds overlap with dry air; dropped the Fire Weather Watches due to low confidence in widespread overlap of critical conditions. By mid-week, the combination of dry air and hot temperatures will drive afternoon RHs into the single digits to teens. Poor to fair overnight RH recovery is forecast through the week, except for locally better recovery in drainages. Late week, confidence is high (70 percent) in a return to breezy westerly winds through the Cascade gaps and across the Columbia Basin as a low-pressure system will likely (70 percent) approach or move into British Columbia. Confidence in the combination of critical winds and relative humidity late Thursday is low-medium (20-50 percent) with medium-high confidence (40-80 percent) for Friday. && .Preliminary Point Temps/PoPs... PDT 49 88 53 93 / 0 0 0 0 ALW 53 90 57 96 / 0 0 0 0 PSC 51 91 54 96 / 0 0 0 0 YKM 55 90 58 95 / 0 0 0 0 HRI 52 90 55 95 / 0 0 0 0 ELN 54 88 57 93 / 0 0 0 0 RDM 42 88 47 95 / 0 0 0 0 LGD 48 88 51 96 / 0 0 0 0 GCD 47 90 51 98 / 0 0 0 0 DLS 58 92 61 98 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until 5 AM PDT Tuesday for WAZ024-026>030- 521>523. OR...Air Quality Alert until 5 AM PDT Tuesday for ORZ041-044-049- 050-502-503-505>507-509>511. && $$ DISCUSSION...86 AVIATION...75 FIRE WEATHER...86

666 FXUS65 KREV 031900 AFDREV Area Forecast Discussion National Weather Service Reno NV 1200 PM PDT Mon Aug 3 2026 .KEY MESSAGES... * A minor dip in temperatures today will precede a prolonged period of triple-digit heat across western Nevada valleys and eastern California basins through next weekend. * Smoke and haze from regional wildfires will continue to impact air quality, particularly across northeastern California and northwestern Nevada. * Dry conditions will persist this week, with low-end precipitation chances starting to pop up this weekend. && .DISCUSSION... Early this week, we have a pronounced upper-level ridge anchored over the Desert Southwest with a weak shortwave trough passing to our north across the Pacific Northwest. This pattern will maintain hot and dry conditions across the region. Smoke and haze from ongoing regional wildfires will continue to be a factor, leading to periods of reduced air quality across the region. Visibility may be impacted, especially in northeastern California and northwestern Nevada. For today, a minor reduction in high temperatures is expected compared to recent days, with western Nevada valleys and eastern California basins generally seeing highs in the upper 90s, though some isolated locations may still reach near 100F. Sierra communities will remain hot, with highs in the upper 80s to low 90s. Overnight lows will provide limited relief, generally ranging from the upper 50s in the Sierra to upper 60s/low 70s in the valleys. By Tuesday and Wednesday, the heat will rapidly intensify as the upper ridge strengthens and shifts slightly eastward. Western Nevada valleys and eastern California basins will see widespread triple- digit temperatures return, with highs climbing into the 100-105F range. Sierra communities will also experience a warm-up as well, with highs reaching the low to mid 90s. Overnight lows will remain uncomfortably warm, generally in the 60s to low 70s for the valleys, and 50s to low 60s for the Sierra. This prolonged heat has necessitated a Heat Advisory for Wednesday, followed by an Extreme Heat Watch from Thursday morning through Sunday morning for much of western Nevada and eastern California. High temperatures across lower valleys will remain at or above triple digits through this weekend with highs generally 100-105F. Sierra communities will see highs consistently in the low to mid 90s. Monsoonal moisture is expected to return to parts of the Southwest US this weekend. NBM guidance shows very low PoPs (5-15%) primarily for Mono and Mineral counties this weekend. -Justin && .AVIATION... * VFR conditions with westerly gusts of 15 kts in the Sierra and NW-NE gusts across NE CA and W NV this afternoon. Smoke and haze from nearby fires may bring periods of reduced slantwise visibility to area terminals through Tuesday. HRICH/Justin && .REV Watches/Warnings/Advisories... NV...Heat Advisory from 8 AM Wednesday to 8 AM PDT Thursday NVZ001- 003>005. Extreme Heat Watch from Thursday morning through Sunday morning NVZ001-003>005. CA...Heat Advisory from 8 AM Wednesday to 8 AM PDT Thursday CAZ070- 071. Extreme Heat Watch from Thursday morning through Sunday morning CAZ070-071. && $$

120 FXUS66 KSTO 031934 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1234 PM PDT Mon Aug 3 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Heat Advisory in effect from until 10 PM tonight for the Valley, Delta, and foothills. - Hottest temperatures of the week are expected today, with areas of Major HeatRisk and Widespread Moderate across the Valley & foothills. Widespread Moderate HeatRisk continues through this week. - Elevated Fire Weather Conditions in the northern Sacramento Valley and surrounding terrain, Burney Basin, and Sierra Foothills through Monday due to hot temperatures, low humidities, and breezy winds. && .DISCUSSION... Today... Strong upper level ridging remains in place over interior Northern California today resulting in widespread Valley triple digit temperatures and the hottest temperatures of the week. Widespread Moderate HeatRisk and areas of Major HeatRisk are expected today as well across portions of the Valley and foothills. As a result, a Heat Advisory is in effect until 10 PM tonight for the Valley, Delta, and foothills. This ridge will weaken slightly tomorrow resulting in slightly "cooler" high temperatures, however overnight lows in the northern Sacramento Valley and foothills will remain elevated in the mid 70s to low 80s tonight into tomorrow. A passing Pac NW trough will continue bring increased north to northwest winds through the northern/central Sacramento Valley and Shasta County through the early afternoon with gusts 15 to 25 mph at times. This in addition to low daytime humidity values into the lower teens and upper single digits and limited overnight humidity recovery, will result in elevated fire weather conditions across the northern Sacramento Valley and surrounding terrain, Burney Basin, and Sierra foothills through today. Additionally, north to east transport winds will bring lofted smoke from surrounding wildfires to Shasta County, Burney Basin, and parts of the northern Sacramento Valley late tonight into tomorrow morning which may result in slightly hazy conditions. Tuesday into this Weekend... Ensemble guidance continues to support the subtle flattening out of the upper ridge through Wednesday which will allow for temperatures to cool off by a few degrees Tuesday-Wednesday, providing some limited relief and slightly cooler overnight temperatures. Additionally, this weakening of the ridge will enhance Delta breeze influence resulting in marginal improvements to humidity recovery and overnight cooling mainly through the Delta and portions of the southern Sacramento Valley. This upper ridge then restrengthens and heights increase Thursday through Saturday, resulting in widespread triple digit Valley temperatures once again with limited overnight relief and a return to widespread Moderate HeatRisk. Despite marginal humidity recovery improvements from the Delta Breeze, low daytime humidity and poor overnight recovery is likely to continue for much of interior NorCal throughout the extended forecast period. && .AVIATION... VFR conditions are expected to prevail over the next 24 hours. Winds generally remain 12 kts or less at TAF sites from Interstate 80 southward. North to northwest gusts 15 to 25 kts are expected in the Sacramento Valley along and west of the I-5 corridor until 21Z Monday. West to southwest gusts up to 20 kts in the Delta from 00Z through 18Z Tuesday. && .STO WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 10 PM PDT this evening for Butte County Below 1000 ft-C. San Joaquin County including Stockton-C. Solano County including Fairfield-C. Stanislaus County including Modesto-C. Yolo/NE Solano including Woodland-Central Colusa County Incl. I-5-Central Glenn Co & Interstate 5-Central Motherlode 1000-3000 ft-E. Diablo Range Above 1000 ft-Eastern Colusa County-Eastern Glenn County-N. Motherlode 1000-3000 ft-N. Sac Valley in Tehama County-NE San Joaquin Valley Below 1000 ft- Sac Metro/W. El Dorado/Amador County-Sacramento County Delta-San Joaquin County Delta-Shasta County Foothills 1000-3000 ft-Shasta Metro-Sierra (Tehama-Plumas) 1000-3000 ft-Southern Motherlode 1000-3000 ft-Sutter/Yuba counties below 1000 ft-Tracy Triangle Below 1000 ft-W Tehama Co Foothills 1000-3000 ft-W. Glenn/Colusa Foothills 1000-3000 ft-W. Stanislaus County Above 1000 ft & I-5- W. Yolo County including Capay/I-505-Yolo / Solano County Hills. && $$

483 FXUS65 KMSO 031903 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 103 PM MDT Mon Aug 3 2026 .DISCUSSION... KEY MESSAGES: - Areas of degraded air quality from regional wildfire smoke. - Warming trend through Friday this week. - Elevated fire weather concerns by Friday, from hot, dry, and breezy conditions. Satellite imagery this afternoon shows widespread smoke impacting the Northern Rockies associated with wildfire activity. This smoke has reduced visibility and has prompted to the issuance of various air quality alerts from the Idaho and Montana DEQ offices. Surface observations highlight a cold front tracking along and east of the divide. Looking ahead to this evening and overnight, a pressure gradient will strengthen along the divide, with easterly winds being felt as far west as the US-93 corridor from Kalispell through the Bitterroot Valley. The strongest winds overnight will focus over the higher terrain, with gusts of 20-25 mph. Confidence is high for a warming trend through Friday this week. Global ensembles show a large ridge of high pressure slowly shifting eastward from the Pacific Northwest over the Northern Rockies by Thursday into Friday. A hot, dry and warm airmass will settle across the region during this time, increasing fire weather concerns. We are closely monitoring Friday for potential critical fire weather as model guidance suggests an upper level wave will move across the ridge, with increasing winds by Friday afternoon and evening. The highest probabilities (40-60%) for gusts to 30 mph or higher are focused along and east of the divide. Looking ahead to next weekend, global ensembles and their clusters suggest the ridge of high pressure will become centered across the Four Corners region, with a dry westerly flow pattern across the Northern Rockies. This pattern suggests seasonably warm temperatures, with little to any chances for precipitation. && .AVIATION...Smoke will continue to be primary impact during the next 24 hours. Surface observations point towards areas of visibility between 3-6 miles across much of the airspace, with valley areas seeing the worst conditions as inversions have been slow to erode this morning into the early afternoon. Looking ahead to this evening an easterly gradient will strengthen along the divide, helping usher in cleaner air for KGPI and KBTM. Generally speaking, the lowest visibilities associated with smoke will be found across central Idaho and along the ID/MT border tonight into Tuesday morning. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

053 FXUS65 KBOI 032014 AFDBOI Area Forecast Discussion National Weather Service Boise ID 214 PM MDT Mon Aug 3 2026 .KEY MESSAGES... - Smoky conditions continue through the week. - Warming this week brings temperatures above 100 degrees by Thursday. - Increased winds Friday through the weekend. && .SHORT TERM /Through Wednesday Night/... Winds today and tomorrow afternoon remain breezy in south- central Idaho before weakening in the midweek. High pressure building over the southwestern US will bring a steady warming trend through the short term. Temperatures climb from 5 degrees below normal to 5-10 degrees above normal by the end of the short term. Northwest flow aloft is carrying elevated smoke from Washington and northeast Oregon into parts of our forecast area tonight. Combined with smoke from the Tartar fire, much of SE Oregon and SW Idaho is forecast to see degraded air quality and visibility through the week. && .LONG TERM /Thursday through Monday/...A ridge of high pressure will reamplify over the area and bring warmer conditions. Temperatures will be 5-10 degrees above normal with lower valleys near 100 degrees Thursday through Saturday. Smoky conditions will continue from area wildfires which may keep temperatures slightly cooler than forecast. Conditions will remain dry and breezy. && .AVIATION /18Z Monday through Tuesday/... Issued 1232 PM MDT MON AUG 3 2026 Reduced visibility due to wildfire smoke, with areas of MVFR-IFR and mountain obscuration. Surface winds: W-N 5-15 kt with areas of gusts to 15-25 kt through the afternoon. Winds aloft at 10kft MSL: NW 5-15 kt. KBOI...Smoky, low VFR with MVFR at times today. Likely degrading to MVFR-IFR Monday evening. Surface winds: NW 5-15 kt. Afternoon gusts around 20 kt. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Air Quality Alert until 2 PM MDT Friday for IDZ011>015-028-029- 033. OR...Air Quality Alert until 1 PM MDT /noon PDT/ Tuesday for ORZ061>064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise SHORT TERM...JM LONG TERM....KA AVIATION.....KA

525 FXUS65 KLKN 031944 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1244 PM PDT Mon Aug 3 2026 .KEY MESSAGES... * Smoke from area wildfires will cause reduced air quality and may lead to respiratory issues. * Unseasonably high temperatures will remain in place through the weekend. Heat related headline products may be needed by mid- to-late week. * Elevated fire weather conditions possible across northern NV Friday through Sunday due to hot, dry, windy weather * Low probability chance of dry thunderstorm activity over central NV this weekend. && .DISCUSSION... (This evening through next Sunday) WEATHER PATTERN OVERVIEW: An active fire season in the Great Basin continues as smoke from area wildfires both in NV and surrounding states is impacting visibility and air quality over the region today. HRRR short term guidance has smoke slowly diminishing over northern NV this evening and less smoke over the area tomorrow. That being said, smoke will likely impact the forecast each day through the short-term. A large dome of high pressure continues to grip the SW CONUS and control the weather pattern through this week. Upper level placement of the HPC to the south keeps northern NV in its northern flank meaning westerly flow aloft. In the lower levels the placement of the HPC meanders between directly overhead and slightly southeast of the region through this weekend. This will mean a southerly shift in low level flow by Wednesday PM/Thursday. This coincides with a marked increase in temperatures for the area. Afternoon highs beginning Wednesday will soar to triple digits. Heat products will be needed for the late week as HeatRisk increases to major and even extreme categories for portions of the area. Stronger westerly flow across northern NV Friday and this weekend, combined with hot temperatures and single digit RH values will bring elevated fire weather conditions mainly for Humboldt and Elko Counties. While wind speeds are slightly below RFW criteria at this time, future model runs will need to be scrutinized for Fire Weather product potential. Long term guidance has an increase in PW values over Nye and White Pine Counties this weekend. Diurnal forcing with the extreme heat will create an environment suitable for convection. Currently low probabilities exist in those locations for a potential return to convective weather by Saturday and Sunday. FORECAST CONFIDENCE & DEVIATIONS: High confidence exists in continued smoky conditions affecting the area through Monday evening as well as warming temperatures that will prompt Heat products by mid week. Moderate confidence exists for elevated fire weather conditions across northern NV late this week. Low confidence exists in dry T probabilities late Saturday and Sunday. Grid edits were not needed for NBM output at this time. && .AVIATION... Areas of smoke from area wildfires will create momentary MVFR/IFR conditions at all terminals through Tuesday afternoon. Otherwise, VFR conditions are forecast through Tuesday with no precipitation anticipated at this time. North-northwesterly wind gusts at KPTH and KELY terminals Monday afternoon will range 15-17KTs before diminishing after sunset. && .FIRE WEATHER... Light winds under high pressure are expected across all fire weather zones Monday and Tuesday. Elevated westerly flow across fire weather zones 437/424/438/469/470 Friday and this weekend are closely being watched. Currently wind speeds fall below RFW criteria but should those increase, the combination of increased speeds with antecedent dry, hot conditions will warrant RFW products for those zones. Sunday a low probability chance exists for dry thunderstorm activity for zones 425/426/427. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...99 AVIATION...99 FIRE WEATHER...86