059 FXUS66 KOTX 232101 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 201 PM PDT Sun Aug 23 2026 .KEY MESSAGES... - Warming and drying trend Monday and Tuesday - Minor to moderate heatrisk Tuesday with highs in the 90s. - Breezy winds Wednesday into Thursday with elevated fire weather conditions. && .SYNOPSIS... Isolated thunderstorms will move out of the area this evening and winds will subside. Temperatures warm Monday into Tuesday with afternoon highs in the 90s by Tuesday. The heat begins to break down Wednesday into Thursday with an increasing risk for breezy winds and mountain thunderstorms. && .DISCUSSION... This evening and tonight: Showers and thunderstorms impacting northeastern Washington and North Idaho will track to the east and come to an end before 6PM this evening. Gusty winds across the region will also subside with quiet weather conditions returning to the Inland NW overnight. Monday-Tuesday: The next low pressure settles into the Eastern Pacific allowing downstream heights to amplify over the Inland NW. This will promote a warming and drying trend with temperatures rebounding into the 80s to lower 90s Monday then 90s Tuesday. Winds will be light with diurnal, terrain influence. The greatest impacts to ongoing fires will be the warm and dry conditions along with increasing instability Tuesday afternoon as mixing heights increase near 10K ft AGL or higher. Wednesday-Thursday: The low pressure system off the coast will begin its slow journey inland. The latest consensus amongst the forecast models are for weaker impulses slinging out ahead of the main low to come through Tuesday night and again Wednesday. These impulses will help draw midlevel moisture northward toward the region though the moistening will be subtle and forcing weak leading to low confidence for high based showers and thunderstorms. The first wave arrives Tuesday with a glancing blow to far southeastern WA and the lower Idaho Panhandle. The second, slightly stronger impulse comes through Wednesday with a 5-20% chance for thunderstorms across the Idaho Panhandle and mountains along the International Border. The upper-low will eventually swing inland across southwestern BC/NW MT Wednesday night into Thursday. Timing will be key to how the winds play out Wednesday afternoon. At this time, timing suggest the low will close enough by late afternoon and early evening for winds to increase slightly during peak heating then continue to ramp up through the evening and overnight hours as cooler air floods inland. This would suggest a short period of breezy conditions overlapping with the hot/dry conditions. However, as previously mentioned, if timing is sooner, we could be looking at another critical fire weather day. Thursday does look breezy to windy across the region similar to what is occurring today (Sunday) as temperatures cool back from the 90s Wednesday to 80s Thursday. Would not rule out additional showers and storms along the Canadian border Wednesday night into Thursday with coverage largely isolated. Friday-Sunday: We see a lot more spread in the model guidance for late week into the weekend with the evolution of the next trough of low pressure. The general message is similar across the board that the Pac NW will continue to be influenced by another trough but how this comes through comes with many different flavors. Some are windy while others not so much. Same message for thunderstorm threats. The greatest confidence comes with temperatures being at or below normal for this time-frame and little to no signals widepsread precipitaiton events. /sb && .AVIATION... 18Z TAFs: There is a 40% chance for showers and thunderstorms across northeastern WA and North Idaho 18-01z. Activity will mainly be along and north of Hwy 20 impacting Republic, Colville, and Bonners Ferry. Otherwise, dry westerly flow will promote VFR conditions for all TAF sites along with breezy west to southwest winds. These winds will quickly decrease between 1z-4z this evening. Winds will slowly shift toward the north and northeast for KMWH, KGEG, KCOE, KPUW overnight. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Main uncertainty and potential for forecast updates will be smoke into KEAT driving down visibility below 6SM. This comes with lower confidence today given the elevated winds in place. ----------------------- 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 53 87 55 94 61 91 / 0 0 0 0 10 10 Coeur d'Alene 53 86 55 95 60 92 / 0 0 0 0 10 10 Pullman 46 86 50 95 54 88 / 0 0 0 0 10 10 Lewiston 56 92 60 99 66 95 / 0 0 0 0 10 10 Colville 43 85 46 94 51 93 / 0 0 0 0 0 10 Sandpoint 46 82 50 91 56 91 / 0 0 0 0 10 20 Kellogg 51 84 53 94 58 90 / 0 0 0 0 10 20 Moses Lake 54 89 57 95 59 92 / 0 0 0 0 0 0 Wenatchee 61 88 64 94 68 92 / 0 0 0 0 0 0 Omak 53 88 58 93 63 93 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until 2 PM PDT Monday for Central Chelan County-Okanogan Highlands-Okanogan Valley-Upper Columbia Basin-Waterville Plateau-Wenatchee Area-Western Chelan County-Western Okanogan County. ID...None. && $$  514 FXUS66 KPQR 232125 AFDPQR Area Forecast Discussion National Weather Service Portland OR 225 PM PDT Sun Aug 23 2026 .SYNOPSIS...Upper level ridging and low-level offshore flow develops Monday, continuing into Tuesday, bringing warmer and sunnier conditions with high temperatures in the mid 80s to lower 90s across the interior lowlands, warmest on Monday. Wildfire smoke will also begin to increase over the Columbia River Gorge, Upper Hood River Valley, and the greater Portland/Vancouver metro area Monday morning and then linger through Tuesday; however smoke is not expected to be dense for most locations. Onshore flow arrives by Wednesday and continues thereafter, which will clear any lingering smoke out of the area and bring relatively cooler temperatures through the end of the week and into the weekend. && .DISCUSSION...Tonight through Saturday Night...Water vapor satellite imagery reveals the upper level shortwave trough lifting across NE Washington into Canada this afternoon. Heights aloft will continue to increase through tonight allowing for clearing skies. As a ridge of high pressure builds aloft over the region, a surface thermal trough develops along the coast extending into western WA early Monday morning. This will allow for light offshore flow to develops, especially over the western slopes of the Cascades with east winds increasing through the Columbia River Gorge later Monday morning. Winds are not expected to be very strong, but gusts up to 25-30 mph will certainly be possible through the western gorge. Temperatures at 850 mb are also expected to rapidly rise to around 20C by Monday evening. Downsloping winds and afternoon mixing will therefore allow for surface temperatures to warm into the upper 80s to lower 90s across much of the inland lowlands, as well as through Cascade valleys, while temperatures at the coast will likely warm into the 70s before winds shift as sea-breezes occur early in the afternoon. This offshore flow will also cause wildfire smoke to begin to filter back down into the valleys, including into the Portland/Vancouver Metro area, Columbia River Gorge and Upper Hood River Valley. However, smoke is not expected to be dense for most locations. By Monday evening, the surface thermal trough is expected to shift east into the Willamette Valley, and potentially to the Cascade crest, allowing for onshore flow to return across much of the area. Lingering low pressure in the valley will likely allow for very light offshore flow to return over the Cascade foothills Monday night into early Tuesday. This will likely maintain elevated overnight temperatures in the lower to mid-60s where the easterly winds persist. A moderate risk of heat related illnesses will therefore exist Monday into Tuesday. Wildfire smoke is also likely to linger into Tuesday as well for northern portions of the forecast area. Early Tuesday, a shortwave trough will lift just offshore, skirting the coast, as a deeper upper level low in the Gulf of Alaska drops south. This should cause a southerly wind reversal to occur along the Oregon coast and into the Willamette Valley. Heights aloft still remain high with the axis of the upper level ridge over the Intermountain West, but 850 mb temps cool to around 16-17C. Still expecting Tuesday temperatures to warm into the mid to upper 80s (about 4-8 degrees above normal). By Tuesday evening, surface high pressure building along the coast will bring a strong marine push of westerly winds. Any lingering wildfire smoke should shift back east of the Cascades by Wednesday. Models and their ensembles are showing fairly good agreement that the upper level trough over the NE Pacific gradually pushes east over the Pacific NW Wednesday through Thursday, with troughing likely persisting over the region through the end of the week and into the weekend. There is high confidence that temperatures trend cooler to near or slightly below average. Confidence is low regarding precipitation, if any will occur later this week. But, if any rain does fall, it would most likely be very light. Best chances would be drizzle along the coast with a weak frontal passage Thursday morning; and again on Saturday, but PoP remains around 15% or less. /DH && .AVIATION...00Z TAFs...Widespread VFR conditions with mostly clear skies will likely prevail from 00Z Monday through 00Z Tuesday, with one potential exception at the coast. By 11Z Monday, KONP has a 50-60% chance for the return of low stratus with ceilings below 1000 ft and surface visibilities around 2 SM or lower. Probabilities for low stratus to return to KAST are lower at around 20%. Inland TAF sites have around a 10-20% chance to see a brief period of MVFR low stratus between 12-17Z Monday. Aside from KONP, these probabilities are not high enough to justify a mention in the TAFs. Expect breezy northerly winds along the coast through 03Z Monday, gusting upwards of 20 kt at KONP. Winds will be relatively weaker inland, mainly out of the north to northwest. Around 18-20Z Monday, easterly winds around 8-11 kt are expected to develop at KTTD and KPDX as offshore winds develop through the Columbia River Gorge. This will also push some wildfire smoke into the Gorge and greater Portland/Vancouver metro area Monday morning. Although dense smoke is not expected, slantwise visibilities may be reduced. In addition, temperatures are expected to warm into the lower 90s Monday afternoon at the inland TAF sites, so be aware of high density altitude which may reduce aircraft performance. KPDX AND APPROACHES...Expect VFR flight conditions with mostly clear skies from 00Z Monday through 00Z Tuesday. Light winds should become northwest around 7-8 kt by 00Z Monday with an incoming sea breeze. Winds become light again by 08Z Monday, before becoming easterly around 8-11 kt sometime between 18-20Z Monday. Once the easterly winds begin, expect increasing wildfire smoke at and near the terminal. Although dense smoke is not expected, slantwise visibilities may be reduced. Temperatures are expected to warm into the lower 90s Monday afternoon at the terminal, so be aware of high density altitude which may reduce aircraft performance. -23 && .MARINE...Northerly winds will gradually increase Sunday afternoon and evening as high pressure strengthens over the northeast Pacific. Gusty winds will develop over the waters, increasing from south to north from Florence to Cape Shoalwater. Wind gusts up to 25 kt are expected to develop Sunday evening over the southern and central waters, and over the northern waters Sunday night. These wind speeds will then persist through Monday afternoon/early evening before decreasing Monday night. Small Craft Advisories remain in effect from 5 PM Sunday to 5 PM Monday for the coastal waters from Florence north to Cape Falcon and from 11 PM Sunday to 8 PM Monday for the coastal waters north of Cape Falcon to Cape Shoalwater. Gusty north winds up to 25 kt are also expected for the Columbia River Bar starting at 8 AM Monday, which also has a Small Craft Advisory in effect. A southerly wind reversal arrives early Tuesday morning over the inner waters with gusts up to 15-20 kt expected by Tuesday afternoon. This will also bring increasing chances for marine fog beginning early Tuesday morning, especially over the inner waters. Visibilities may fall below 1 SM at times as the southerly winds develop and upwelling occurs. Aside from the increasing winds and potential marine fog, significant wave heights look to remain relatively low at around 3 to 5 ft through Friday. -23 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Small Craft Advisory from 8 AM to 8 PM PDT Monday for PZZ210. Small Craft Advisory from 11 PM this evening to 8 PM PDT Monday for PZZ251-271. Small Craft Advisory from 5 PM this afternoon to 5 PM PDT Monday for PZZ252-253-272-273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland  729 FXUS66 KSEW 232127 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 227 PM PDT Sun Aug 23 2026 .SYNOPSIS... An upper level trough will continue to move east of Western Washington today. Drier and warmer weather Monday and Tuesday as an upper level ridge builds over the Pacific Northwest. An upper level low will approach the area around midweek, bringing increasing onshore flow and cooler temperatures to Western Washington for the second half of the week. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... An upper level trough continues to push across Washington this afternoon. Partly cloudy skies this afternoon with high temperatures in the low to mid 70s across the interior and mid 60s along the coast. An upper level ridge will build over the Pacific Northwest on Monday, with the ridge axis east of the Cascades on Tuesday. This will bring warmer and drier conditions. The warmest day will be Tuesday. High temperatures are expected to peak in the mid 60s/low 70s along the coast. Across the interior, temperatures will climb into the 80s and low 90s in the Cascade valleys. This will reintroduce widespread areas of Moderate HeatRisk for the Everret-Seattle-Tacoma Metro and Cascade valleys. Additionally, surface flow will transition more northerly to easterly Monday and Tuesday, resulting in wildfire smoke being transported from nearby fires in British Columbia and Eastern Washington into Western Washington. 29 && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... There is good agreement between ensemble guidance that an upper level low will approach the Pacific Northwest on Wednesday and an upper level trough will settle over the region through late in the week. This pattern will reinstate onshore flow across Western Washington and bring cooler temperatures. Latest guidance has high temperatures trending slightly below normal in the the low to mid 60 along the coast and low to mid 70s across the interior. Low temperatures by the end of the week will trend towards the low to mid 50s. Chances for precipitation look to return on Wednesday and continue into the weekend. However, the latest QPF amounts indicate precipitation will be light. While thunderstorm chances remain at 10% or less, they could be a possibility on Wednesday and Thursday as the upper level low swings north into British Columbia and brings southwesterly flow aloft over Western Washington. 29 && .AVIATION... An upper ridge begins to build into the area tonight through Monday, which will result in westerly flow aloft becoming southwest on Monday. VFR cigs this afternoon with lingering areas of MVFR mainly from PAE northwards. Clouds will slowly clear into this evening. LIFR stratus will develop along the coast tonight. LIFR cigs are also expected across the Strait of Juan de Fuca by early Monday. Some uncertainty exists as to the extent of stratus around central Puget Sound Monday AM. At this time, LIFR cigs are expected to be confined to PAE and nearby river valleys. Otherwise, mainly VFR elsewhere with a few high clouds on Monday with haze increasing aloft late Monday with more of an E flow in the mid levels. Winds at the surface will transition more north this evening, increasing from the north Monday afternoon. KSEA...VFR cigs this afternoon with continued mid level clouds. Cigs will slowly clear into this evening. LIFR stratus will push inland along the Strait of Juan de Fuca into early Monday. VFR conditions are expected on Monday as the stratus is anticipated to remain north of the terminal. There is approx. a 10% of LIFR cigs between 13-17z. W/SW surface winds will transition to N/NW around 23-00z this afternoon. Winds remain NE tonight at 5 to 9 kts. JD && .MARINE... High pressure continues to build over the Coastal Waters today and will remain in place through Tuesday. North winds will increase on Monday, particularly for the Coastal Waters and Puget Sound. Will need to monitor for SCA wind gusts late Monday afternoon through Monday evening for the Coastal Waters, with current probabilities of SCA gusts around 40 to 70 percent during this period. Onshore flow then increase Tuesday night through Wednesday as a weak frontal system moves across the waters midweek. This may result in SCA west winds through the Strait of Juan de Fuca beginning Tuesday night. Onshore flow then continues late in the week. Seas around 3 to 5 feet may briefly peak towards 7 feet for the southern Coastal Waters late Monday with increasing north winds. This may lead to brief choppy waters with a period around 6 seconds. Otherwise, 4 to 5 foot seas are expected Tuesday through much of the week. JD && .FIRE WEATHER... An upper-trough has progressed off and away from western Washington this afternoon. Conditions have trended drier but marine stratus has remain well entrenched as shown by recent satellite imagery. Guidance is in lock-step regarding a ridge building into the region on Monday into Tuesday. A thermal trough will also snake along the coast during this time, leading to a warm-up and drier conditions as light offshore flow develops. Isolated areas of min RHs reaching near critical thresholds are possible during this time in the Cascades. Onshore flow then returns Tuesday night into Wednesday as another upper-trough enters the region. Showers as well as the chances for more thunderstorms are possible around the midweek timeframe. Less certainty in how the pattern will evolve towards the second half of the week. Solutions are hinting at an upper-trough swinging a pair of upper-lows into the region but there is disagreement in exact timing and track. Nonetheless, below normal temperatures, onshore flow and the potential for precipitation appears to be in the offing towards the weekend. 41 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...None. && $$  680 FXUS66 KMFR 232141 AFDMFR Area Forecast Discussion National Weather Service Medford OR 241 PM PDT Sun Aug 23 2026 .KEY MESSAGES... && .DISCUSSION...The upper trough that has been guiding conditions over the weekend has moved on to the northeast, leaving southwest flow aloft under the western side of a continental ridge. This pattern will bring some warming to most areas today, with easternmost Lake and Modoc County seeing similar temperatures as on Saturday. Monday will be the warmest day of the forecast period for most areas. Temperatures west of the Cascades may reach up to 10 degrees above normal, while to the east highs look to be about 5 degrees above normal. A passing shortwave will bring elevated winds into the Shasta Valley, the Klamath Basin, Christmas Valley, and parts of the Rogue Valley. For western Siskiyou County, Jackson County, and western Cascades foothills, these winds align with ongoing dry conditions to possibly reach critical fire weather conditions. A Red Flag Warning has been issued for Monday afternoon and evening to highlight these concerns. This shortwave is also support slight (15- 20%) thunderstorm chances over eastern Modoc and Lake counties, given its interactions with monsoonal moisture moving over those areas. While the chances for thunderstorms are not high enough to meet Red Flag criteria, any thunderstorms that do develop can still be locally hazardous by bringing lightning strikes or erratic and gusty winds. On Tuesday, an approaching trough around a low pressure system over the Pacific will shift flow to be more southerly. With dry air aloft precipitation is not expected. Temperatures west of the Cascades will drop a bit, but highs across the area look to stay about 5 degrees above normal. A weak front swinging around that trough may bring marine drizzle and some inland cloud cover On Tuesday morning, but significant impacts are not expected. For midweek and into the weekend, the upper trough starts to work against high pressure centered around the Four Corners area. The first low will weaken and move off to the northeast but another low follows to keep the trough in place possibly through Saturday. With this pattern, slow and steady cooling would bring generally seasonable warmth across the area by Friday or Saturday. Upper disturbances may bring elevated breezes on Friday, but details that far out are hard to forecast with high confidence. Overall, the forecast through the rest of August looks to be unimpactful. -TAD && .AVIATION (18Z TAFs)... The marine layer is beginning to dissipate and should allow for a period of VFR conditions this afternoon for KOTH. However, expecting the marine layer to redevelop tonight and bring another round of IFR conditions overnight. Otherwise, VFR conditions expected for inland TAF sites, and typical diurnal winds expected today/tonight with some high clouds potentially infiltrating the region overnight. -Guerrero && .MARINE...Updated 230 PM PDT Sunday, August 23, 2026...Gusty north winds and steep wind-driven seas are building steep seas across area waters this afternoon. These winds will persist through Monday morning. The main belt of stronger winds will push into the outer waters Monday afternoon and evening, with a southerly surge of wind and fog along the inner waters Monday night into Tuesday. Generally light winds and calm seas are then expected through Friday with low pressure persisting over the northeastern Pacific. && .FIRE WEATHER...Updated 230 PM PDT Sunday, August 22, 2026... With ongoing dry conditions, a passing shortwave will bring elevated winds to areas west of the Cascades. These winds will be southerly in the Shasta and could approach 30 to 35 mph. The Scott Valley could also see southerly winds approach20 to 25 mph. In the eastern Rogue Valley, westerly winds could reach 20 to 25 mph. With RHs forecast to be in the 10-15% range, this combination represents critical fire weather conditions as any new fires could quickly spread. A Red Flag Warning for gusty winds and low RHs has been issued for California fire weather ones 280 and 281 as well as Oregon fire weather zones 621, 622, and 623. This Warning will be in place from 11 AM through 8 PM on Monday. Also on Monday, There are some signals for thunderstorm chances across far eastern 285/625, namely the Warner and Hart mountains. Much will depend on how far west the Four Corners High retrogrades behind this trough passage. Otherwise, another trough drops southward from the Gulf of Alaska and lingers off the BC coast through early next week. There will likely be additional shortwaves/troughs to swing through the region early next week, bringing periods of enhanced winds. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Red Flag Warning from 11 AM to 8 PM PDT Monday for ORZ621>623. CA...Red Flag Warning from 11 AM to 8 PM PDT Monday for CAZ280-281. PACIFIC COASTAL WATERS...Small Craft Advisory until 11 AM PDT Monday for PZZ350-356. Small Craft Advisory until 8 PM PDT Monday for PZZ370-376. && $$ TAD/TAD/TAD  192 FXUS66 KPDT 232153 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 253 PM PDT Sun Aug 23 2026 .KEY MESSAGES... - Above-normal temperatures Monday through Wednesday as an upper-level ridge of high pressure builds overhead then shifts east to the northern Rockies. - Very low chance (5-15%) of showers and thunderstorms for the southern Blue Mountains on Monday, and for the northern Blue Mountains on Tuesday. - Breezy westerly winds Wednesday, with low-medium probability (20-60%) of Red Flag conditions in the Columbia Basin and Cascade gaps. && .DISCUSSION... Water vapor imagery shows an upper-level low exiting the region to the east over southern Canada and the northern Rockies. Meanwhile, a large, upper-level closed low is churning in the Gulf of Alaska, and a somewhat smaller and weaker closed low is located to our west in the eastern Pacific. At the surface, widespread breezy conditions are present beneath dry zonal flow in the wake of the low, with the most notable winds through the Cascade gaps, Columbia Basin, and Blue Mountain foothills. Temperatures are seasonably cool, a few degrees below normal. An upper-level ridge of high pressure is forecast to build overhead tonight into Monday and gradually shift east over the northern Rockies through Wednesday. This will result in warming, mostly dry conditions areawide. Above-normal temperatures are anticipated to peak in the 90s for most areas on Tuesday, with portions of northeast Oregon seeing similar temperatures on Wednesday. Accompanying HeatRisk looks to peak Tuesday/Wednesday with medium-high (50-100%) probability of Moderate (level 2 of 4) HeatRisk for the majority of our population centers. A few areas of the Columbia Basin have low-medium (10-45%) chances of Major (level 3 of 4) HeatRisk. Moderate HeatRisk affects those who are sensitive to heat, especially those without cooling/hydration, while Major HeatRisk affects anyone without cooling/hydration. While mostly dry conditions are forecast Monday through Wednesday, would be remiss for not mentioning the low probabilities (5-15%) of convection each day. Ensemble NWP guidance is in excellent agreement that the aforementioned lows will slowly approach the Pacific Northwest by later Monday, with a weak shortwave embedded in southwest flow aloft passing over northern California and southeast Oregon late afternoon and evening. This will present a low (5-15%) chance of high-based showers and thunderstorms for the far southern Blue Mountains. Any showers and thunderstorms that develop will be capable of producing strong, gusty outflow winds. Tuesday, guidance merges the two offshore lows, and wraps a weak shortwave (the remnants of the smaller low) up the Pacific coast. While the wave is not forecast to move inland across our forecast area, weak synoptic-scale forcing coupled modest diurnally induced instability, negative mid-level theta-e lapse rates, and very marginal mid-level moisture indicate some potential for afternoon convection. Best chances (5-15%) are for the northern Blue Mountains, and the rest of far northeast Oregon. By Wednesday, guidance shows yet another shortwave swinging around the parent offshore low, with low (5-15%) chances of convection again over the Blue Mountains. There is higher confidence (20-60%) in overlap of breezy winds and critically low relative humidity in the Columbia Basin and Cascade gaps Wednesday, per NBM probabilities. Thursday through the remainder of the week, anticipating near- normal temperatures and diurnally breezy westerly winds through the Cascade gaps. && .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Slightly breezy winds at PDT/ALW/DLS Today with gusts (20-25kts) tapering off around 7 or 8 pm. Elsewhere lighter (under 12 knot) winds at YKM/PSC/RDM/BDN, with VFR at all terminals. && .Preliminary Point Temps/PoPs... PDT 49 90 54 94 / 0 0 0 0 ALW 55 93 61 95 / 0 0 0 0 PSC 53 93 57 96 / 0 0 0 0 YKM 57 91 61 95 / 0 0 0 0 HRI 53 92 58 95 / 0 0 0 0 ELN 51 87 57 93 / 0 0 0 0 RDM 45 91 49 94 / 0 0 0 0 LGD 49 93 56 97 / 0 0 0 10 GCD 52 95 57 96 / 0 0 0 0 DLS 59 94 64 97 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Air Quality Alert until noon PDT Monday for WAZ026-522-523. OR...Air Quality Alert until noon PDT Monday for ORZ041-044-049-050- 502-503-505>507-509>511. && $$ DISCUSSION...86 AVIATION...71  267 FXUS65 KPIH 232154 AFDPIH Area Forecast Discussion National Weather Service Pocatello ID 354 PM MDT Sun Aug 23 2026 .KEY MESSAGES... - Slight Risk Today (60–80 mph Severe Gusts): The Storm Prediction Center (SPC) maintains a Slight Risk across the southeast corner of the region—including the South Hills, lower Snake Plain, and southeast highlands toward Bear Lake. Steep lapse rates and high moisture will support severe downburst winds of 60 to 80 mph and localized small hail through late evening. - Repeat Threat Tomorrow: Near-identical synoptic conditions on Monday will keep scattered thunderstorm potential elevated across the same southeastern footprint, with localized damaging gusts remaining the primary hazard. - Mid-Week Ridge & Late-Week Wind Surge: High pressure rebuilds Tuesday and Wednesday, bringing above-normal temperatures in the upper 80s to lower 90s alongside isolated afternoon storms. A passing northern shortwave on Thursday and Friday will increase regional winds and moderate weekend temperatures back toward seasonal averages in the low-to-mid 80s. && .DISCUSSION... Issued at 156 PM MDT Sun Aug 23 2026 An active afternoon and evening are expected across eastern Idaho as an unusually moist and unstable air mass remains entrenched across the southeastern portion of the forecast area. Surface temperatures climbing into the 80s paired with surface dewpoints in the mid-50s are providing sufficient thermodynamic instability for robust convective development. The Storm Prediction Center (SPC) maintains a Slight Risk for severe thunderstorms across the southeast corner, encompassing the South Hills, the lower Snake Plain, and the southeastern highlands around Bear Lake. Soundings reveal steep low-to-mid level lapse rates, creating an environment characterized by strong evaporative cooling within convective cores. Stronger thunderstorm cores and organized outflows will be capable of generating scattered severe wind gusts of 60 to 80 mph within the Slight Risk zone, with a lower but non-negligible wind threat extending across the rest of eastern Idaho. Small hail will also be possible within the strongest cores. High- resolution convective-allowing models (CAMs) show storm activity persisting through late evening before tapering off around midnight. Synoptically, Monday presents a near-identical setup. High- resolution model guidance targets the same general footprint across the South Hills, Snake Plain, and southeastern highlands for afternoon shower and thunderstorm coverage. SPC currently carries a Marginal Risk for severe gusts across the area. However, if daytime destabilization matches today's parameters, localized severe downburst wind gusts will once again be the primary operational threat. As the upper-level trough assisting current convective activity exits into Western Canada, high-pressure ridging will attempt to rebuild over the Great Basin Tuesday through mid-week. Residual low-level moisture trapped beneath the ridge axis will maintain low-end daily shower and thunderstorm chances. Afternoon maximum temperatures will run a few degrees above seasonal climatological norms, reaching the upper 80s to lower 90s across lower-elevation valleys. Heading into the late-week period, a shortwave trough tracking into Washington and British Columbia on Thursday will tighten regional pressure gradients, increasing wind speeds across eastern Idaho on Thursday and Friday. This northern feature will partially suppress the Great Basin ridge Friday into the weekend, potentially lowering valley temperatures back toward seasonal benchmarks in the low-to-mid 80s. However, considerable spread remains among model ensemble guidance regarding the exact magnitude of this weekend cooling trend.&& .AVIATION /18Z TAFS THROUGH 18Z MONDAY/... Issued at 354 PM MDT Sun Aug 23 2026 Scattered to strong severe thunderstorms will continue through 06z this evening. Most storms will stay south of TAF locations, but we are continuing a hedge for a rogue storm at most locations. && .FIRE WEATHER... Issued at 156 PM MDT Sun Aug 23 2026 Another day with monsoon moisture across Idaho means another day with showers and thunderstorms. We will see isolated thunderstorms across the central mountains (Zone 476) and along the Montana border for Zone 411. There is a 10-40% chance for gusts over 35 mph. There is a better chance south of the Snake River across Zones 427 and 413, although coverage remains borderline for scattered and Red Flag Warning thresholds. Down south is also where we expect for a slightly higher chance for wetting rainfall, but it is still only 15-30%. There is also a 50-90% chance for gusts over 35 mph. Any thunderstorms today have the potential for gusts over 60 mph, similar to yesterday, but the chance for those types of gusts is highest down south. While there is no strong indication outflow boundaries or storms are expected across Zones 410 and 425, we will be watching for that as well. Outside of storms and outflow potential, gusty winds will develop across the central mountains(422/475/476), the Arco Desert and Upper Snake Plain (410) and along the Montana border (411). Gusts in the 25-40 mph range are expected. There will be pockets of lower humidity (around or below 15%), but the potential looks too sporadic for widespread critical conditions and Red Flag Warnings. Monsoon moisture spreads back north across eastern Idaho tonight and tomorrow. We will be borderline again across Zones 413 and 427 tomorrow for scattered coverage. We expect isolated storms across a good chunk of eastern Idaho, outside of Zone 475. The chance of wetting rain is similar to today (15-30%) but the footprint is a bit bigger overall, but still look for a mix of wet and dry storms. There is a less than 50% chance for gusts over 35 mph closer to the Montana border, but 70- 90% across the rest of eastern Idaho where storms develop, with a distinct possibility again for gusts over 60 mph with stronger storms and outflow boundaries. The risk of showers and storms continues until the end of the week. We may see another low pass to our north, which would suppress deeper moisture to south of the Snake Plain over the weekend. Right now, there is quite a range on what might have with the storm track, and the Blend of Models does include a few showers and storms across a good portion of eastern Idaho especially on Saturday. && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$ DISCUSSION...McKaughan AVIATION...13 FIRE WEATHER...Keyes  320 FXUS65 KRIW 232155 AFDRIW Area Forecast Discussion National Weather Service Riverton WY 355 PM MDT Sun Aug 23 2026 .KEY MESSAGES... - Monsoonal moisture continues this afternoon and evening but not as widely scattered as Saturday with localized flooding possible in the strongest storms. - Strong to severe storms possible (30-40%) looking more like the evening time frame after 6PM with a line of storms from Idaho capable of producing damaging winds up to 60 mph. - Monsoonal moisture will linger much of the week, with a chance of showers and thunderstorms each day. Temperatures will be closer to seasonable for this time of year nearing the end of August. && .UPDATE... Issued at 1200 PM MDT Sun Aug 23 2026 Much more ample sunshine across the CWA for the noon update as compared to yesterday. As such, temperatures will be a couple degree warmer this afternoon as Saturday afternoon as well. With better mixing, there will be a stronger breeze to go along with it as well gusting up to 25-30 mph at times outside of any storm activity and outflow winds. Nothing on radar currently but HiRes data is still pinpointing development by 2-3PM off leeside of the Absarokas and pushing in from the south off the Uintas for Sweetwater County. Much of this activity will be isolated in nature compared to yesterday's showers but expect lightning and a brief outflow over 40 mph with its eastward progression through the evening. With this, PoPs have been adjusted and especially after the CRON wiped out the night shift's work to account for this heading into the evening hours. This is where it will get a bit more interesting at least for Wyoming standards. A line of storm activity looks to form from southern Montana and across eastern Idaho by 6-7PM before pushing east into western Wyoming shortly there after along and ahead of the cold front. This will track through the CWA by Monday morning. SPC continues with the Marginal Severe Risk, with an introduced Slight to the southwest portions of the state to include hatched wind. This looks to be overdone, even though damaging winds are possible up to 60 mph from the outflows ahead of the front. The instability with DCAPE values less than 500 J/kg just don't look to impressive as it nears radiational cooling towards sunset. There might be an hour or so before darkness, but the FROPA will be later further south for the CWA with its positive tilt and progressive eastward push. Stronger winds than that don't look great in the least but something to keep an eye on between 6-10PM west of the Divide. Beyond that as it makes its way to the east after midnight, the juice of the storms will be lost with mainly shower activity in its wake. The cold front will push the warmer moist air south and southeast. Beyond that, status quo, as the monsoonal pattern continues but to a bit lesser extent. Temperatures behind this aforementioned cold front will bring afternoon highs closer to seasonable for this time of year ending the month of August with 80s east of the Divide even into next weekend. && .DISCUSSION... Issued at 226 AM MDT Sun Aug 23 2026 It was a typical monsoon day yesterday, with some areas, mainly in southwest and in Johnson and Natrona Counties getting a LOT of rain, causing some local flooding. Other areas saw nothing. And we continue to have some showers and embedded thunder around late tonight, although intensity is significantly less. And these will continue through the night, gradually becoming weaker and less numerous. We will have another round of showers and storms today. There are some differences. For one, precipitable water values are less today by about 20 percent in most locations. This should bring less coverage and somewhat lesser rainfall rates. The other difference is thatthere will be more steering flow today, generally about 10 to 15 knots at 700 millibars and 25 to 35 knots at 500 millibars. So storms should have more movement. This should decrease the chance of flooding somewhat. We still have an excessive rainfall outlook across most ares West of the Divide though, so the threat is still there. There is also the risk of strong to severe thunderstorms. Most of the area is under a marginal risk of severe weather today. There could be some small hail, but this not the main risk. The main risk looks to be strong wind gusts. Roughly north and west of a Buffalo to Riverton to Lyman line has a Conditional 1 outlook for wind, or possible convective wind gusts to 75 mph. Soundings do show some inverted V profiles, especially across northwestern Wyoming where the surface will be drier, with low and mid level lapse rates close to 9 C/Km. This could lead to some strong downburst winds later today. Again, the best chance would be across the northwest but most areas will have a chance. And, like previous nights, most convection should end after sunset but a few showers and storms will likely linger through the night. As for temperatures, they should be a few degrees warmer than yesterday with more sunshine expected. The rest of the week looks like more of the same as the annoying monsoonal moisture will hang around the area through at least Thursday and possibly into Friday as well. The models continue to have different ideas on which day will be more active with no real well defined shortwaves with changes from day to day. Precipitable water generally average about 125 to 150 percent of normal through the period though. So, at this point we went with a generic solution of mainly diurnal showers and storms each afternoon. Temperatures should remain fairly similar through the period, not very hot but averaging around 4 to 8 degrees above normal on average, with the possibility of a cooler day if there is more cloud cover than expected. Drier air may then work in for next weekend and bring a return to drier weather but uncertainty remains high on the exact timing. So, all in all, it continues to look like more of the same as the summer of the monsoon lives on in western and central Wyoming. && .AVIATION /00Z TAFS THROUGH 00Z TUESDAY/... Issued at 355 PM MDT Sun Aug 23 2026 Most showers and thunderstorms end through about 03z. Lingering chances continue overnight for southwestern Wyoming, including KBPI, KPNA, and KRKS and should be done by sunrise, if not sooner. Outside any convection, winds lessen overnight, following typical diurnal trends. Isolated showers and thunderstorms are again possible Monday afternoon. Please see the Aviation Weather Center and/or CWSU ZDV and ZLC for the latest information on icing and turbulence forecasts. && .RIW WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Lowe DISCUSSION...Hattings AVIATION...Wittmann