581 FXUS66 KSEW 031821 AFDSEW Area Forecast Discussion National Weather Service Seattle WA 1021 AM PST Tue Feb 3 2026 .SYNOPSIS... High pressure will build over the region Tuesday through the remainder of the week, bringing in unseasonably warm and dry conditions with rounds of morning fog and low stratus. A pattern change is on tap for the weekend, with wet and cooler conditions returning. && .SHORT TERM /TODAY THROUGH THURSDAY/... High pressure brings a period of dry and mild weather to western WA through the remainder of the work week. Expect highs in the mid to upper 50s with 60s in the interior on Wednesday. Lows will be a little cooler Thursday morning with 30s over the south sound. 33 && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Wet and cooler weather returns over the weekend as the ridge shifts east and a trough moves in from the west. Snow levels will lower to around 4000 feet on Sunday with accumulating snow possible on the higher peaks and passes like Stevens Pass. Ensemble members favor a cool and wet pattern moving into next week for more lowland rain and mountain snow. 33 && .AVIATION... Light west to southwest flow aloft expected over Western Washington into tonight as an upper ridge axis builds over the interior West. The low level flow is weakly offshore. The ridge will remain rather dirty today with varying amounts of high and mid level moisture filtering across the area as a frontal system moves into the British Columbia coast late today. Patchy LIFR stratus/fog across the Southwest Interior will gradually lift and scatter this afternoon. High level moisture will begin to thin late tonight and, coupled with weak surface flow, is likely to lead to the return of LIFR/IFR stratus and fog on Wednesday morning from around KSEA/KBFI southward. KSEA...Varying amounts of high and mid level clouds will continue into tonight. As discussed above, the coupling of thinning high clouds and weak surface gradients lends moderate confidence to the return of fog and/or low clouds at the terminal again early Wednesday morning. Surface winds light and variable much of today trending more easterly tonight at 7 knots or less. 27 && .MARINE... A decaying system well offshore will bring seas back up to 10-12 feet later this evening into Wednesday. As a result, a SCA has been issued again for the outer coastal waters. SCA level winds are also possible around this time - but mainly for the outer coastal waters where a 40-45% chance exists. As high pressure builds into today through the remainder of the work week, expect periods of marine fog over the next few days. Visibility restrictions in Puget Sound and the coastal waters are possible as fog and/or low stratus develops. Seas 10-12 ft through Thursday morning, before setting around 9-10 ft thereafter. && .HYDROLOGY... The Skokomish River will fall below flood stage late this morning or early afternoon and will continue to recede. The river will rise again early next week and crest near minor flood stage again. Flooding is not expected elsewhere over the next 7 days. 33 && .SEW WATCHES/WARNINGS/ADVISORIES... WA...None. PZ...Small Craft Advisory from 4 PM this afternoon to 4 PM PST Wednesday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm-Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm. && $$

373 FXUS66 KPQR 031752 AAA AFDPQR Area Forecast Discussion National Weather Service Portland OR 952 AM PST Tue Feb 3 2026 Updated Aviation, Marine, and Beach Hazards discussions. .SYNOPSIS... High pressure continues to build over the Pacific Northwest today, establishing a dry and mild pattern that is expected to persist through at least Friday. Clear skies, light winds, and persistent low-level inversions will support areas of fog and frost across interior lowland valleys through much of the week. In addition, stagnant air conditions may develop in some interior valleys. Breezy easterly winds through the Columbia River Gorge will help limit air stagnation impacts across the Portland and Vancouver metro area and portions of the west-central Willamette Valley. && .DISCUSSION...Now through Sunday...Upper-level ridging becomes firmly established over the region today, marking the start of an extended period of dry weather and above-normal temperatures. Mid to high-level cloud cover may linger through portions of the day as a Pacific system tracks well north into British Columbia along the northern periphery of the ridge. However, clouds are expected to gradually thin and clear, with sunnier conditions becoming more widespread Wednesday and Thursday. Afternoon high temperatures through the end of the work week are forecast to reach the upper 50s to lower 60s, roughly 10 degrees above climatological average for early February. Wednesday looking to be the warmest day of the work week by a degree or two. Despite the mild daytime temperatures, clear nights and light winds will promote strong nocturnal inversions across interior valleys. These inversions will favor the development of fog and low stratus during the overnight and morning hours, particularly within the Willamette Valley and other sheltered lowland locations. There remains some uncertainty regarding the low-level moisture, as model soundings indicate easterly to east-southeasterly flow around 1000 to 2000 feet above ground level may inhibit stratus formation in some areas while surface winds remain calm. This scenario would result in a favored fog pattern rather than stratus, especially in locations removed from the influence of the Columbia River Gorge outflow. Patchy frost will also be possible during the overnight and early morning hours where skies remain clear and winds decouple. Winds during the ridging period will generally be light across most of the forecast area, though notable exceptions are expected in and near the Columbia River Gorge. Strengthening east-west pressure gradients will lead to breezy easterly gap winds, particularly on Wednesday and Thursday. Deterministic and ensemble guidance suggests pressure gradients between Troutdale and the Dalles will range from approximately -5 to -6 mb on Wednesday and increasing overnight to around -7 to -8 mb by Thursday morning. Few members indicate gradients as strong as -9 mb during Thursday morning. Probabilities for wind gusts exceeding 35 mph are around 15 to 25 percent in the far eastern Portland and Vancouver metro area on Wednesday and 25 to 35 percent on Thursday. Additionally, there is a 70 to 90 percent chance for gusts to exceed 35 mph within the western Gorge and adjacent terrain. Exposed ridgetops such as Crown Point and Three Corner Rock have a 30 to 50% chance of experiencing gusts exceeding 50 mph. Away from the Gorge, persistent ridging, light winds, and low mixing heights will contribute to stagnant air conditions. An Air Stagnation Advisory remains in effect from early Tuesday morning through Friday afternoon for the southern Willamette Valley, east- central Willamette Valley, north and central Oregon Cascade foothills, north Clark County lowlands, and the lower Columbia and Cowlitz River valleys. The Portland and Vancouver metro area and the west-central Willamette Valley were excluded from the advisory due to better low-level mixing associated with easterly Gorge winds, which gradually veer more northerly farther south into the west- central valley. In addition to air quality concern, the stagnant pattern will continue to support fog and frost potential across interior valleys throughout the week, with front potential most notable on Thursday and Friday. Attention then turns to the weekend, when confidence decreases regarding the timing of the next precipitation event. Ensemble guidance indicates a return to wetter conditions is likely, though timing varies. Approximately 75 percent of ensemble members bring precipitation back into the region by Saturday afternoon, while others delay the onset until Sunday morning. Most ensemble guidance also suggest a transition toward cooler temperatures through the weekend and into next week. While details remain uncertain, the overall pattern suggests a cooler and wetter regime developing late this weekend into early next week. ~12 && .AVIATION...Fog/low stratus formed across portions of the Willamette Valley and lower Columbia and Cowlitz County valleys this morning, creating pockets of IFR/LIFR conditions. Lower vis and cigs are beginning to improve as of 17z Tue, and all locations should improve to VFR conditions by 19-20z Tue. Then VFR conditions through the rest of the day before fog formation is possible again tonight into Wednesday morning across the inland valleys. Conditions expected to begin deteriorating to MVFR/IFR between 06-09z Wed with more widespread IFR/LIFR vis by 10-12z Wed. Chances for fog formation are much lower (10-15%) around KPDX due to continued east winds from the Columbia River Gorge. Any lowered conditions should improve to VFR by 18-21z Wed. Winds will remain easterly through the Columbia River Gorge. stronger than yesterday with gusts around KTTD reaching 25-30 kt. Within the Willamette Valley, winds above 1000 ft AGL will be southerly while at the surface winds will be variable. KPDX AND APPROACHES...Fog at KPDX is expected to improve to VFR by 18-19z Wed. Winds become easterly around 18z Wed less than 10 kts. After 06-09Z Wed, there`s a 10-15% chance of fog reformation. If winds remain easterly then there fog likely won`t reform. However, if winds shift northerly or become variable, chances increase for fog formation. -03 && .MARINE...Variable winds with gusts up to 15 kt will be the trend through Friday. Wave heights this morning are around 7-9 ft at 10-12 seconds, and will remain here through this evening. An increasing westerly swell will push into the waters late tonight, increasing seas again to around 10-12 feet around 12-16 seconds. Seas will remain elevated above 10 feet through the end of the week, and a Small Craft Advisory will need to be considered. -03 && .BEACH HAZARDS...A moderate threat for sneaker waves continues today before another long-period westerly swell pushes into the waters tonight through Wednesday night, causing another high threat for sneaker waves. A Beach Hazards Statement has been issued for 4 AM PST Wednesday through 1 AM PST Thursday for the coasts of northern/central Oregon and southern Washington. Waves will be able to run significantly farther up on a beach than normal, including over rocks and jetties. Sneaker waves can suddenly knock people off of their feet and quickly pull them into the frigid ocean which may lead to serious injury or drowning. Caution should be used when in or near the water, especially those who will be razor clamming this week. -03 && .PQR WATCHES/WARNINGS/ADVISORIES... OR...Air Stagnation Advisory until 4 PM PST Friday for ORZ108- 115>118-123>125. WA...Air Stagnation Advisory until 4 PM PST Friday for WAZ204-205. PZ...Small Craft Advisory until 7 AM PST this morning for PZZ210- 251>253-271>273. && $$ www.weather.gov/portland Interact with us via social media: www.facebook.com/NWSPortland x.com/NWSPortland

113 FXUS66 KMFR 031126 AFDMFR Area Forecast Discussion National Weather Service Medford OR 326 AM PST Tue Feb 3 2026 .Updated AVIATION Discussion... && .AVIATION...03/12Z TAFs...VFR conditions will prevail for most of the area through the TAF period. The exception will be in the Umpqua Basin and Illinois/lower Rogue Valleys where LIFR conditions in fog will persist through the morning hours. Patchy fog is possible in the Klamath Basin as well as the Medford area around sunrise, and could briefly impact the Medford and Klamath Falls terminals this morning. Any lower conditions should improve to VFR by 17-18z today, possibly linger until 20z in the Illinois Valley/Grants Pass area. Expect another round of LIFR conditions to return to similar areas tonight into Wednesday morning. && .PREV DISCUSSION... /Issued 239 AM PST Tue Feb 3 2026/ DISCUSSION...Satellite imagery this morning shows fog developing in the Umpqua Basin and the Illinois Valley/Grants Pass area. Skies are clear for the remainder of the area with some scattered high level clouds moving through. There could be some patches early morning fog in the Rogue Valley and Klamath Basin around sunrise, but this should be shortlived with plenty of sunshine expected today. Once fog and low clouds clear by late morning, sunny skies and above normal afternoon temperatures are expected across the region today. High pressure remains in control for the remainder of the week, resulting in similar day to day conditions with areas of overnight/morning fog/low clouds in West Side Valleys that will give way to sunny skies and seasonably warm temperatures. Overall, the going forecast is on track and no updates are needed. Please see the previous discussion below for more details. MARINE...Updated 200 AM PST Tuesday, February 3, 2026...Improved conditions are expected today as swell dominated seas lower for a brief time. Steep seas are likely to return late tonight into Wednesday as another building west swell arrives and combines with a persistent southwest swell. These steep seas may continue through Friday. High pressure will maintain dry conditions through Friday. Then a front may move into the area and bring rain along with a potential for steep west-southwest seas on the weekend. PREV DISCUSSION... /Issued 1003 PM PST Mon Feb 2 2026/ DISCUSSION (Today through Sunday)... Key Points: * Little to no impacts expected until this weekend - Precipitation chances increase Sat/Sun - Snow levels dropping to 4500 Sun night - No hazards expected at this time * Morning fog thru Thurs for West Side valleys and some East Side areas * Above normal temperatures and dry conditions will persist - Warmest days will be today - Thursday - Record warmth possible for Alturas and Klamath Falls - Brookings may approach 70 degrees on Wednesday Further Details: The forecast turns largely dry the upcoming week with above normal temperatures. In fact, high temperature records may be met at Alturas and Klamath Falls midweek. Records are 65 (Feb 4th) and 64 (Feb 5th) for Alturas. Record is 59 for Klamath Falls on Feb 5th. Each of these days we are forecasting high temperatures within a degree or two of these records. A Rex Block (high pressure on the poleward side of a closed low) sets up at 500mb over the West Coast starting tomorrow. This will keep the pattern stagnant through much of next week. The high of this Rex Block will be centered over the forecast area through middle parts of the week which will help aid our above normal temperatures for this time of year. This pattern does appear to break down Thursday into Friday as a closed low develops over the Pacific and enters the PacNW. This will bring our next chance of precipitation starting Saturday morning. A lot will depend on the strength of the high as this low could get pushed to the north. At this time, we are not seeing any noteworthy impacts from rainfall, but we will need to keep an eye on snow levels and wind speeds. Currently, the probability for 6.0" of snowfall in 24hrs is around 40% through Sunday night for a small area around Crater Lake. Otherwise, light snowfall possible at similar elevations. Again, at this time, we are not expecting widespread hazardous weather. -Guerrero && .MFR WATCHES/WARNINGS/ADVISORIES... OR...None. CA...None. PACIFIC COASTAL WATERS...None. && $$

642 FXUS66 KEKA 030740 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 1140 PM PST Mon Feb 2 2026 .SYNOPSIS...Unseasonably warm and dry conditions will build through midweek especially on the coast. Light rain is most likely to return this weekend,= mostly focused on the northern half of the area. && .DISCUSSION...A moderate ridge, currently centered over California, will slowly meander just east of the area over the next two days. At the moment, this has promoted shallow marine fog near shore and mostly calm winds. As the ridge pushes east through midweek, it will help generate persistent, moderate easterly wind. This will promote dry and clear conditions, even at the coast, Tuesday through Thursday. Coastal conditions are likely to be unseasonably warm. Wednesday and Thursday, there is 30% chance of highs reaching 70. There is slight potential (about 15%) on Thursday of reaching the high temperature record for the day in Eureka of 73. Highs in the interior will also be warm, though not record breaking, most likely in the mid 70s for warmer valleys such as Ukiah and in Lake County. There is high ensemble agreement that an elongated, but weak trough will sweep across the area around Friday and into the weekend. The first effects of the trough will increasing cloud cover and generally cooler and more moist condition by Friday. A thin band of moisture will be pulled onshore, most strong around Cape Mendocino, behind the trough. This band, however, appears very weak in ensembles and will have little instability to work with, limiting any high end rain potential. That said, model ensembles still place about a 70% chance of wetting rain all along the coast around Saturday and Sunday. Rainfall would be mostly focused along the the North Coast with most likely rainfall amounts of 0.1 to 0.5 inches. This initial round of rain would be mostly light and associated with little wind. Deterministic models currently support a much strong and deeper trough then crossing the area as soon as Sunday into early Next week. There is much more uncertainty with this system compared to Saturday. While there is much greater high end potential, only about 50% of ensemble members support robust enough moisture to constitute a weak to moderate atmospheric river event. Because of that, there is a very wide range in current precipitation forecasts. About 20% of models show no rain at all with a mostly likely rainfall range of 0.4 to 1.6 inches along the coast. In higher end scenarios, precipitation could reach near 3 inches at higher elevations. There is good agreement, that the greatest chances of heavier rain are isolated to the northern most part of the area, with a narrower mostly likely range in Mendocino and Lake Counties of 0.2 to 1.0 inches. Should the determinist models prove right, this system could have the potential for some impactful winds over 45 mph and possible snow levels as low as 3000 feet, but too much variability remains to really nail down scenarios for those variables quite yet. /JHW && .AVIATION...Coastal cloud cover is much less widespread this morning as compared to last night. Patchy IFR to LIFR condition are expected along the coast into the morning hours. Interior areas will also see some fog formation overnight in the valleys with gradual mixing to VFR by the afternoon, though the Ukiah valley should remain clear. Winds will remain light across the region with high pressure building aloft. /RPA && .MARINE...Westerly swells are now subsiding and will continue to decrease in height through the day on Tuesday into Tuesday night. High pressure over the region will keep winds light across the coastal waters Tuesday and again on Wednesday. The next westerly swell will build into the waters Thursday into Friday allowing seas to build back to around 10 feet. The models have been trending down with the magnitude of this swell, so the potential for small craft advisory conditions is a little more questionable than what seemed more likely only 24 hours ago. /RPA && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... None. && $$ NOTE: The full forecast discussion is now regularly issued between 10 am/pm and 1 pm/am. Additional updates will be issued as needed. Visit us at https://www.weather.gov/eureka Follow us on Facebook and Twitter at: https://www.facebook.com/NWSEureka https://www.twitter.com/NWSEureka For forecast zone information see the forecast zone map online: https://www.weather.gov/images/eka/zonemap.png

603 FXUS66 KMTR 031728 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 928 AM PST Tue Feb 3 2026 ...New AVIATION... .KEY MESSAGES... Updated at 220 AM PST Tue Feb 3 2026 - Above normal temperatures and dry conditions through the work week - Hazardous beach conditions from late Wednesday night through Saturday evening at Pacific Coast beaches - 20 to 40% chance of rain developing north to south on Sunday, with the higher amounts favoring the North Bay and the coastal mountains. && .UPDATE... Issued at 833 AM PST Tue Feb 3 2026 Visible satellite imagery reveals clear skies for nearly the entire area this morning. Exception to this would be interior Contra Costa County where Tule Fog extends from the Delta south into the San Joaquin Valley. Anticipate this lingering fog in Contra Costa to gradually mix-out over the next several hours. Temperatures as of the 8 AM hour are running at or a few degrees above where were were at this same time yesterday morning. Forecast remains on track at this time. // Rowe && .SHORT TERM... Issued at 220 AM PST Tue Feb 3 2026 (Today and tonight) Another day of warm and dry conditions today as high pressure builds overhead. Temperatures this morning will start out cool once again, mainly in the 40s, thanks to mostly clear skies across the area. Patchy fog in the North and East Bay valleys as well as the southern Salinas Valley will quickly dissipate after sunrise. Light offshore winds this afternoon will boost the warming provided by the ridge and mostly sunny skies, with highs up to 5 degrees warmer than Monday. This will place high temperatures around 5 to 15 degrees above seasonal normals, with mid 60s to lower 70s near the coast and 70s to near 80 inland. Conditions tonight will be very similar to this morning, with lows a couple degrees higher and patchy fog expected in the same general areas. && .LONG TERM... Issued at 220 AM PST Tue Feb 3 2026 (Wednesday through Monday) The warmest day of the period at most locations will be Wednesday as the ridge reaches peak strength and begins to shift east, allowing offshore winds to tick up. This will push highs up a few more degrees from today. On Thursday, highs should cool slightly as the ridge continues to move away. On Friday and Saturday, a weak low will move near the coast and into southern California. Impacts will be minimal, but clouds will increase and winds will turn onshore, continuing the cooling trend. A more significant pattern change will take place Sunday and Monday as a deeper trough moves into the Pacific Northwest. This will bring potential for light precipitation and a cold front as the trough progresses. Latest ensemble guidance has delayed the onset of precipitation, but chances increase increase from north to south through the day Sunday. The chance of rain rises above 20 percent by Sunday morning across the North Bay, Sunday afternoon for the greater SF Bay area, and Sunday evening for the Central Coast. Rain chances continue at around 20 to 40 percent into Monday. As our area remains on the southern fringe of this system, rain amounts are trending light and low impact overall. However, temperatures will cool to near or even slightly below normal, and winds may become locally breezy. && .AVIATION... (18Z TAFS) Issued at 929 AM PST Tue Feb 3 2026 Terminals are clear for 18z taf issuance with nearest fog bank over the Central Valley. Light easterly winds to continue today into tonight. Patchy fog possible overnight for KSTS and KAPC but low confidence. Mainly clear skies with light easterly winds continues Weds as peak of 500 mb ridge axis passes overhead. Vicinity of SFO...VFR skies with light NE winds. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals... VFR with clear skies. Locally strong SE winds in the Salinas Valley night and early morning hours. && .MARINE... (Today through Sunday) Issued at 319 AM PST Tue Feb 3 2026 Moderate seas and gentle northerly breezes will persist into midweek. Moderate northwesterly breezes and building seas will result in a return of rough seas late Thursday night and Friday, continuing into the weekend. && .BEACHES... Issued at 319 AM PST Tue Feb 3 2026 A Beach Hazards Statement is in effect from 12 AM PST Thursday to 9 PM PST Saturday at all Pacific Coast beaches. Westerly swell will bring an increased risk for sneaker waves and strong rip currents with breaking waves of 14 to 19 feet. Remember to stay off of jetties, piers, rocks, and other waterside infrastructure, remain out of the water, and never turn your back on the ocean! && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Beach Hazards Statement from late Wednesday night through Saturday evening for CAZ006-505-509-529-530. PZ...None. && $$ SHORT TERM...Tangen LONG TERM....Tangen AVIATION...RW MARINE...Canepa Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea

324 FXUS66 KOTX 031743 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 943 AM PST Tue Feb 3 2026 .KEY MESSAGES... - Dry and mild through Friday. - Wetter weekend expected with incoming front Saturday Night into Sunday && .SYNOPSIS... Tuesday will see return of upper level ridge over the Pacific Northwest. The forecast then trends drier again. Temperatures will remain mild and above normal. Cold front over weekend will bring precip and breezy winds. && .DISCUSSION... Today through Friday: Models continue to be in good agreement of a strong upper level ridge building over the region through Thursday, then weakening and starting to push east on Friday. The magnitude of the ridge continued to be advertised as a 99th percentile for this time of year, meaning in the top 1 percent as 500mb heights climb to near 580 decameters, and 850mb temperatures reach values near 10C (50F). While a warming trend is a done deal in the mountains, many of the lower elevations will be plagued by stratus as a moist boundary layer is in place. This will be especially true for the northern valleys, East Slopes of the Cascade valleys, and the Moses Lake area. Yet some easterly flow in the boundary layer and slightly higher sun angle may allow the stratus to break up at times over NE WA/N Idaho Panhandle. And over the Palouse and LC Valley downslope southeast boundary layer winds should allow for warmer temperatures as well with highs climbing into the 50s. Locations that stay in the stratus all day will struggle to get out of the low to mid 40s. Currently the National Blend of Models forecast seems reasonable given some model spread in temperatures. Saturday through Monday: Ensembles are in good agreement that the ridge will finally give way completely, allowing an upper trough and an associated wet system to pass through the Inland NW. Precipitable waters along and ahead of a cold front increase to 150-200 percent of normal. Snow levels will initially be high ahead of the front, ranging from 5000-6000 feet through Saturday night as precipitation moves in. Then as the cold front passes on Sunday snow levels drop to 4000-4500 feet, and then to around 3000 feet behind the front on Monday with post-frontal showers favoring snow showers along the Cascade crest and Idaho Panhandle mountains. Currently however the chances for significant mountain snow for Sunday/Monday are low, with a 50% chance for 2 inches or more at Stevens Pass, and a 40% chance for similar amounts at Lookout Pass. Yet additional weather systems are shown by the ensembles next week as the cooler and unsettled pattern continues. JW && .AVIATION... 18Z TAFS: Fog will continue at KGEG-KSFF through Tuesday morning with a moist boundary layer. Fog will lift into an IFR and eventually MVFR stratus into the afternoon. HREF showing conditions improving to VFR into the afternoon but not buying that with the strength of the mid level ridge building today. KPUW-KLWS will remain VFR with thanks to level easterly flow. MVFR conditions to continue for KEAT-KMWH through the day. Ceilings trend towards IFR in the late this evening again with light northeast flow for KGEG-KSFF-KCOE-KEAT. FORECAST CONFIDENCE AND/OR ALTERNATE SCENARIOS: Low confidence with the degree of improvements for Tuesday afternoon. HREF usually is too optimistic with improving conditions under strong high pressure. Moderate confidence that conditions remain VFR through the TAF period (18z Wednesday) for KPUW/KLWS. ----------------------- 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 47 34 50 32 49 33 / 0 0 0 0 0 0 Coeur d`Alene 47 36 50 33 51 33 / 0 0 0 0 0 0 Pullman 52 37 53 37 54 35 / 0 0 0 0 0 0 Lewiston 55 39 55 37 56 37 / 0 0 0 0 0 0 Colville 43 33 47 32 48 31 / 0 0 0 0 0 0 Sandpoint 43 36 47 33 47 33 / 0 0 0 0 0 0 Kellogg 48 38 53 37 56 38 / 0 0 0 0 0 0 Moses Lake 49 34 50 33 51 33 / 0 0 0 0 0 0 Wenatchee 44 36 47 35 47 35 / 0 0 0 0 0 0 Omak 44 36 45 35 47 34 / 0 0 0 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... WA...Dense Fog Advisory until noon PST today for Spokane Area. ID...None. && $$

841 FXUS66 KPDT 031754 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 954 AM PST Tue Feb 3 2026 .KEY MESSAGES... - High pressure returns to the region Tuesday - Pattern change expected over the weekend && .UPDATE... Areas to Widespread dense fog has expanded over some well traveled areas this morning, particularly the Kittitas and Yakima Valley as well as the Oregon Washington Highway along the Foothills of the Blues. Latest LAMP guidance keep the low visibility anchored though at least noon, so went ahead with issuing dense fog advisories for these areas This Morning. The next step is to determine how quick this fog redevelops Tonight assuming it all lifts. Russell/71 && .DISCUSSION... Current radar shows no returns as the shortwave warm front has traversed to the east. The nighttime satellite shows some fog forming through the Kittitas Valley with ground observations showing VIS to be decreasing along the I90 corridor. Patch fog will continue through the morning before clearing out later in the morning. Models show the upper level ridge already building into the region. This will bring increasing stratus and potential fog back to the area over the next few days. While this pattern during winter does typically bring with it the potential for air stagnation, the NBM shows mixing heights to hover above 1500 feet and the abundance of low clouds expected through the period. However, fog will remain the daily concern through the period ahead of the next system. 50-60% of the raw ensembles show that Tuesday morning Kittitas, Yakima and a large swath through the Columbia Basin will see VIS drop as low as if not lower than 3 miles. By Wednesday, probabilities increase to 60-70% of 3 miles or less VIS through much of the Columbia Basin and Klickitat County along the Simcoe Highlands and along the Northern Blue Foothills. By Thursday models show the axis of the high to tilt and the back edge of the high will bring in southerly flow. This will bring in air warmer and has the potential to decrease the chances of fog forming overnight Thursday and Friday (60-70% confidence). By Saturday models show the initial breakdown of the ridge as an upper level low begins to build in offshore bring increased precipitation chances (70-90%) to the Cascades and spreading to the eastern mountains Saturday night with 40-60% chances. Clusters and models are in decent agreement through the weekend, there is a telltale difference in the timing between models. The Euro has precipitation coming in ahead of the GFS. Regardless, precipitation and cooler temperatures are expected over the weekend. 90 && .AVIATION...18Z TAFs...Fog and low stratus will brings periods of MVFR or lower conditions across most sites through the period. Sites DLS/PDT/YKM/ALW/PSC will be stuck under the stratus layer for most of the period, with hires short term guidance attempting to clear PDT/PSC out by this afternoon, but confidence is low (<20%) in these solutions. CIGs are expected to remain mostly at MVFR or lower heights through the period. Confidence is mod-high (50-80%) that these sites will also see lowered vsby impacts throughout the period as the associated fog layer moves around the lower elevations. That said, confidence is low (20-30%) on exact timing of the vsby impacts. Site RDM/BDN are expected to remain clear and dry through the period. Winds will be light, 12kts or less, through the period. Lawhorn/82 && .Preliminary Point Temps/PoPs... PDT 34 50 32 48 / 0 0 0 0 ALW 37 50 35 48 / 0 0 0 0 PSC 34 48 34 49 / 0 0 0 0 YKM 35 50 32 50 / 0 0 0 0 HRI 35 49 33 48 / 0 0 0 0 ELN 33 45 29 46 / 0 0 0 0 RDM 29 60 27 56 / 0 0 0 0 LGD 36 56 37 56 / 0 0 0 0 GCD 33 59 34 59 / 0 0 0 0 DLS 38 51 36 50 / 0 0 0 0 && .PDT WATCHES/WARNINGS/ADVISORIES... WA...Dense Fog Advisory until noon PST today for WAZ026-027-029. OR...Dense Fog Advisory until noon PST today for ORZ507. && $$ UPDATE...71 DISCUSSION...90 AVIATION...82

129 FXUS65 KREV 030850 AFDREV Area Forecast Discussion National Weather Service Reno NV 1250 AM PST Tue Feb 3 2026 .KEY MESSAGES... * High pressure overhead will bring dry conditions, above average afternoon highs, light winds, and valley inversions through this week. * The high pressure may weaken by this weekend with precipitation chances returning by the second week of February, but confidence is low. && .DISCUSSION... We`re expecting the 3 C`s this week: cool, calm, and collected conditions (4 C`s?). High pressure builds over the region, continuing the trend of light winds, cool/mild afternoon highs, valley haze, and dry conditions. Localized areas of freezing fog may also develop for fog-prone Sierra valleys each morning this week before dispersing by late morning. Furthermore, air quality reductions are possible in and around areas of prescribed burns due to strong inversions. Check fire.airnow.gov for local readings. In other news, this meteorologist (and another, more infamous one) managed to see her shadow today! My winter and snow lovers, rejoice! And looking at long-range guidance, the models look to agree with this statement. The next best chance to get snow along the Sierra is late this weekend (Sunday at the earliest) as a shortwave drops down the coast of California. However, with this low-level feature and the fact that it`s about a week out, there`s plenty of time for that low to wobble in any direction, leaving confidence low on the extent of impacts. The NBM does hint at snow levels between 5.5-6.5 kft though, so we might just be in luck! -Giralte && .AVIATION... VFR conditions and light winds continue through this week. The only exception will be at KTRK where lower CIGS/VIS is possible due to patchy FZFG development between 09-16Z tonight. Slantwise visibility reductions possible for KRNO/KCXP/KMEV due to valley inversions and haze in the mornings each day this week. -Giralte && .REV Watches/Warnings/Advisories... NV...None. CA...None. && $$

549 FXUS66 KSTO 022216 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 216 PM PST Mon Feb 2 2026 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Dry weather with patchy morning fog in the Valley through the week. - Pattern change late weekend and into early next week, with potential for precipitation. && .DISCUSSION... ...Today through Friday... Skies are partly to mostly sunny across the area, with a few hazy spots. Temperatures have warmed into the 70s in the northern Sacramento Valley and 60s elsewhere in the Valley. Areas in the mountains are in the 40s to 50s. Ridge of high pressure will remain in place through the week, with light and variable winds and morning fog. HREF continues to show fog each morning through Friday for areas in the southern Sacramento Valley towards the northern San Joaquin Valley. Around the Sacramento area fog will be patchy, with visibility reductions to a half mile, while areas in the northern San Joaquin Valley sees reductions to a quarter mile or less. This will be a rinse and repeat situation through Friday. Thus, we have issued another Dense Fog Advisory from 6z through 18z for the northern San Joaquin Valley for tonight into tomorrow morning. Besides the fog, conditions will remain dry with low RH values in the teens to 20s for the mountains each afternoon through Friday. Temperatures will continue to be above normal this week, with a slight cooling trend over the weekend. ...Saturday and onward... Dry conditions and seasonal temperatures on Saturday, with a change in the ridging over the southwestern United States come Sunday. Ensembles have started to pick up on a pattern change taking shape end of the weekend and into early next week that would break down the ridge and introduce precipitation chances. At this time, ECMWF and GFS ensembles have hinted at the possibility of widespread precipitation for the region, with a continued active pattern through all of next week. Probabilities at this time for over a quarter of an inch of precipitation are 30-40 percent for the Valley, and over 60 percent for the foothills, mountains, and Shasta county area. Confidence is low at this time on rain/snow amounts, timing, and breakdown of the ridge. && .AVIATION... VFR conditions expected through the evening, with conditions turning IFR to MVFR as visibilities drop. Patchy dense fog around 05-06z for SAC, SMF, MHR, and MCC through 15-16z. Visibility reductions down a half mile at times for those locations. Areas in the northern San Joaquin area will see more widespread dense fog, with visibilities of a quarter mile or less. RDD and RBL will remain VFR through the TAF period. && .STO WATCHES/WARNINGS/ADVISORIES... Dense Fog Advisory from 10 PM this evening to 10 AM PST Tuesday for Northern San Joaquin Valley. && $$

116 FXUS65 KMSO 031940 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 1240 PM MST Tue Feb 3 2026 .DISCUSSION... KEY MESSAGES: - High pressure this week will result in warm temperatures and stagnant air - Record-breaking daytime high temperatures on Thursday - A pattern shift Feb 8-10 will bring increased precipitation chances A ridge of high pressure will build over the Northern Rockies today and last through the remainder of the work week. Temperatures will remain well above normal. The forecast for Thursday shows record-breaking (or tying) daytime high temperatures for Missoula, Kalispell, and Butte. The lower Salmon River valley could see 70 degrees. One caveat to the high temperature forecast will be atmospheric stability and the ability for some valleys to hang onto colder air under inversions. Inversions will likely trap low stratus and fog in the valleys, particularly across northwest Montana and Clearwater County. Looking ahead, ensemble clusters continue to suggest a pattern shift early next week. Current guidance indicates the ridge will break down as an upper-level trough digs along the West Coast. This transition would open the door for increased precipitation chances and a cooling trend, though confidence regarding the strength of this system remains low for both the timing and intensity of the trough. && .AVIATION... GOES satellite imagery shows a ridge of high pressure building across the western US, with the Northern Rockies under northwesterly flow aloft. Waves of high clouds will continue to stream into the area from the northwest through tonight into Wednesday morning. Patchy areas of valley fog and low stratus will develop tonight given stable conditions under the ridge. This rings true for KGPI and KMSO, where probabilities of LIFR visibility associated with fog is 15-20% between 04/1000-1500Z. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$

256 FXUS65 KBOI 031718 AFDBOI Area Forecast Discussion National Weather Service Boise ID 1018 AM MST Tue Feb 3 2026 .DISCUSSION...Satellite is revealing several layers of cloud cover this morning. We`ll continue to see periods of clouds today with moisture rolling over the top of the ridge. Morning fog/haze will improve some over lower valleys with the limited mixing we see today. We`re still looking at a stagnant air mass remaining in place through this weekend, so expansion of fog/stratus is possible. Current forecast is on track for today. && .AVIATION...Mainly VFR, areas of haze resulting in MVFR visibilities in the lower Treasure Valley and near KMUO. Conditions improving to VFR through the morning. Surface winds: Variable up to 10 kt. Winds aloft at 10kft MSL: W-NW 10-20 kt. KBOI...VFR under thin high clouds. Surface winds: Light and variable, leaning NW after Tue/20z then leaning SE after Wed/03z. && .AIR STAGNATION...Current Air Stagnation Advisory has been extended until 5 AM MST Monday morning. The inversion will gradually weaken Saturday and Sunday, and a cold front Monday should be strong enough to break the inversion and provide enough mixing wind to scour the stagnant air out of the valleys. && .PREV DISCUSSION... SHORT TERM...Today through Thursday night...Upper level ridge will reach maximum amplitude Wednesday directly over our CWA. It will easily be the strongest ridge in the middle latitudes anywhere in the northern hemisphere. This will cause abnormally warm daytime temperatures above 5500 feet MSL, with an intense inversion below that will maintain air stagnation in the valleys. We expect fog and low clouds to slightly increase next two nights but hi-res models don`t yet have it. The ridge will begin to break down Thursday as the axis shifts slightly to our east. Higher elevations will cool slightly but the inversion will continue in the valleys. LONG TERM...Friday through Tuesday...The upper ridge will continue to gradually break down and shift east this weekend, finally allowing our CWA to come under moistening southwest flow aloft. On Monday a north Pacific cold front and supporting upper trough will come inland with a 50-70 percent chance of rain and snow in our CWA (highest chance in northern areas), and just as important, mixing winds and a likely end to the inversion. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...Air Stagnation Advisory until 5 AM MST Monday IDZ012-014-016-033. OR...Air Stagnation Advisory until 5 AM MST /4 AM PST/ Monday ORZ062>064. && $$ www.weather.gov/Boise Interact with us via social media: www.facebook.com/NWSBoise www.x.com/NWSBoise DISCUSSION...DG AVIATION.....NF SHORT TERM...LC LONG TERM....LC AIR STAGNATION...LC

279 FXUS65 KLKN 031947 AFDLKN Area Forecast Discussion National Weather Service Elko NV 1147 AM PST Tue Feb 3 2026 .KEY MESSAGES... Updated at 1129 AM PST Tue Feb 3 2026 * High pressure this week over the Great Basin will threaten several high temperatures records across the area through Thursday * Potential for precipitation and gusty winds returns to NV beginning late this weekend && .DISCUSSION... (This afternoon through next Tuesday) WEATHER PATTERN OVERVIEW: High pressure continues its dominance over Nevada to start the forecast, bringing near record temperatures today through Thursday. While the high pressure is in place, temperatures continue to be well above average and no precipitation will be possible. This system will begin to exit east by Friday, allowing a more active pattern in the West to take shape. This active pattern is expected to become especially evident by Sunday as a longwave trough begins to move onshore from the Pacific Ocean, bringing Pacific moisture with it. PoPs begin to increase Sunday afternoon in northern Nevada, expanding into central Nevada by mid morning Monday. Precipitation potential extends through the end of the forecast at this time and while PoPs at any given time and location max out around 60% with this forecast, the current indication is that the entire coverage area can expect at least some precipitation. Temperatures are also expected to return to much more seasonal levels and this system is currently expected to begin as a valley rain/mountain snow mix before potentially changing over to a full snow setup by next Tuesday. Early long range indicators are also signaling active weather potential through the first half of the month. FORECAST CONFIDENCE & DEVIATIONS: High confidence for high pressure persistence and associated impacts through Friday. Low to moderate confidence regarding the weather system beginning Sunday. Consistency has increased regarding time and location but there is still high uncertainty for factors such as temperature, PoPs and accumulation. No deviations from NBM baseline were included in this forecast. && .AVIATION...VFR conditions will persist at all terminals through Wednesday morning under high pressure. No precipitation is forecast for the period and winds will be light. && .LKN Watches/Warnings/Advisories... None. && $$ DISCUSSION...94 AVIATION...99