000 FXUS66 KSEW 161045 CCA AFDSEW Area Forecast Discussion National Weather Service Seattle WA 355 AM PDT Thu Sep 16 2021 .SYNOPSIS...An upper ridge will bring dry weather today. A vigorous frontal system will bring rain and windy conditions on Friday. An upper trough will bring cool and showery weather over the weekend with isolated thunderstorms possible. Drier and more tranquil weather is expected the first half of of next week. && .SHORT TERM /TODAY THROUGH SATURDAY/...Pretty quiet this early morning as upper level ridging exerts its influence over W WA. Current satellite imagery shows that while some low clouds are present, the seem to be moving southward and thinning out a bit. Current radar is clear. This upper level ridge will remain the main weather factor for the rest of today allowing dry conditions to continue and generally sunny skies over much of the area. High temps will run a little bit below normal with mid to upper 60s for most lowland locations, lower 60s along the coast. A vigorous frontal system will move through the area Friday and Friday night, bringing rain, heavy at times, and windy conditions to some locations, particularly the North Interior /including western portions of Skagit and Whatcom counties/ as well as the Admiralty Inlet area and the San Juans. A wind advisory is up for this area as well as for along the coast for much of the day Friday. Models remain consistent with fairly impressive rain totals for the area as the front moves through slowly throughout the day. The mountains look to pick up 2-4" of rain with locally higher totals possible while lowland locations should get 1-2" of rain. Highs Friday expected to be in the lower to mid 60s. The front pushes further inland Saturday, moving east of the Cascades by mid-morning. In its place, the parent upper level trough will take up residence over W WA allowing for showers to continue for much of the day. The trough itself looks to have enough dynamics with it to bring some instability and thus looking at a slight chance for some thunderstorms, mainly during the afternoon and evening hours. Snow levels will fall to 6500-7000 feet on Saturday and the higher terrain should get the first accumulating snows of the season. 18 .LONG TERM /SUNDAY THROUGH WEDNESDAY/...The trough axis finally starts making its way east of the Cascades Sunday, however the back end of the trough still has plenty of moisture for shower chances to continue. Lingering instability will once again give rise for a limited thunderstorm threat over portions of W WA. The aforementioned snow levels will remain fairly static, so once again additional snowfall on the highest terrain remains a possibility. High temps Sunday expected to be impressively below normal /10 or more degrees below in some spots/ with highs only in the lower 60s areawide. Deterministic models are quick to dry things up as an upper level ridge sets up for the start of next week, however enough uncertainty remains in ensemble members that PoPs cannot be entirely ruled out for the remainder of the forecast period. These PoPs remain low /generally slight chance to low-end chance/...so the overall thought across the board, deterministic and ensemble, is a relative dry period. High temps each day should be mostly in the 60s. 18 && .AVIATION...Mostly clear skies except a few patches of mainly valley fog around daybreak. The air is dry and stable. High clouds will arrive late today ahead of a cold front that will reach the area on Friday. 19 KSEA...Mostly clear skies, some high clouds later today. && .MARINE...Not much in the way of wind today, but southerlies will increase overnight tonight and a vigorous cold front will arrive on Friday with gale warnings for the coastal waters and north, with small craft advisory winds elsewhere. 19 && .HYDROLOGY...A vigorous frontal system will bring heavy rains to the area Friday and Friday night. River flooding is not expected at this time with dry antecedent conditions and low river flows but sharp rises on areas rivers are likely. There is an outside chance the exceptionally flood-prone Skokomish river in Mason county could reach flood stage Saturday morning. Localized minor urban flooding is also possible on Friday in areas of heavier rains. Schneider && .SEW WATCHES/WARNINGS/ADVISORIES... WA...Wind Advisory from 5 AM to 8 PM PDT Friday for Admiralty Inlet Area-Central Coast-North Coast-San Juan County-Western Skagit County-Western Whatcom County. PZ...Gale Warning from 5 AM to 11 PM PDT Friday for Coastal Waters From Cape Flattery To James Island 10 To 60 Nm-Coastal Waters From Cape Flattery To James Island Out 10 Nm-Coastal Waters From James Island To Point Grenville 10 To 60 Nm- Coastal Waters From James Island To Point Grenville Out 10 Nm-Coastal Waters From Point Grenville To Cape Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville To Cape Shoalwater Out 10 Nm. Gale Warning from 5 AM to 5 PM PDT Friday for East Entrance U.S. Waters Strait Of Juan De Fuca-Northern Inland Waters Including The San Juan Islands. Small Craft Advisory from 8 AM to 11 PM PDT Friday for Admiralty Inlet-Puget Sound and Hood Canal. && $$ www.weather.gov/seattle

000 FXUS66 KPQR 161134 AFDPQR Area Forecast Discussion National Weather Service Portland OR 349 AM PDT Thu Sep 16 2021 .SYNOPSIS...An upper ridge will bring dry and seasonable weather today. A potent Pacific frontal system will usher in cool, wet, and blustery weather to the entire forecast area by Friday night, where rain will be locally heavy into Saturday. Cool and showery conditions will follow into Sunday, while isolated thunderstorms are possible both Saturday and Sunday. Rain will be orographically enhanced over the Coast Range and Cascades, where over three inches of rain is possible. && .SHORT TERM /Today through Sunday/... In the calm before the storm, an upper ridge will bring dry weather today. This morning`s dry airmass has allowed for minimum temperatures down into the upper 30s to mid 40s, which will quickly warm today into the mid 70s in the lowlands and into the mid 60s in the higher terrain and along the coasts. Clouds should begin increasing tonight Clouds will begin increasing tonight as the vigorous weather system moves in closer, while winds will turn more southerly. A warm front will rise up over the area ahead of the surface low digging down along the western B.C. coast, increasing the southerly winds. Overall, models have slowed the system a bit, so have adjusted the arrival of the precipitation, however they continue to keep the strongest forcing and moisture transport north of our area on Friday, mainly toward the Olympic Peninsula and Vancouver Island. With the slower arrival time and strong southerly winds, have warmed Friday`s high temperature forecast, especially over the southern Willamette Valley. Further north, light rain and drizzle will spread inland north and west of Portland during the daytime hours. Southerly winds will increase, especially along the coast. Model guidance continues to show possible gusts to 50 mph Friday evening here, with up to 35 mph possible for the Willamette Valley. The brunt of the system is expected to push in late Friday night through Saturday morning, when the cold front slides across the forecast area. The frontogenesis has trended slightly stronger than previous model runs, ahead and under the 115+kt jet aloft. Rain will become heavier, mainly in the midnight to sunrise on Saturday time frame for areas near Portland and northwest, then sunrise to noon south and east of Portland. Instability with the frontal passage and good turning of the lower level winds may allow for isolated thunderstorms Saturday afternoon and into the evening. Snow levels will be lowering to near 7000 feet by Saturday noon then down to near 6000 feet by Saturday night through Sunday. Widespread rain showers will continue Sunday with the continued chance for thunder as the upper level trough passes overhead. Sunday`s temperatures will be down in the 50s to low 60s. /Kriederman && .LONG TERM...Monday through Thursday...Showers may continue Monday morning, but overall should be pretty much done. Total rainfall amounts for the weekend event continues to range around 1-2 inches for the inland valleys by Monday morning, and 2-4 inches for the higher terrain. Deterministic models build in an upper ridge quickly after the departing weather system. Yet that ridge will be shoved east just as quick as another upper trough pushes in from the Pacific, quite normal in this changing of seasons. A chance of rain will come again for Tuesday into Wednesday, before agreement between the models becomes poor quite quickly. /Kriederman && .AVIATION...A quiet period today and tonight with a cool, dry air mass in place and an upper ridge building over the region today. Some residual moisture over southwest WA brining spotty MVFR cigs to the south WA & north OR coast early this morning, but should be gone by sunrise. Also some of the more wind sheltered valleys will have patchy fog through mid morning. For detailed regional Pac NW aviation weather information, go online to: https://weather.gov/zse KPDX AND APPROACHES...VFR expected next 24 hours as dry, stable conditions continue. Northerly winds will pick again to around 10 kts this afternoon into early evening. /mh && .MARINE...A relatively quiet period for the about the next 24 hours as surface high pressure over the waters remain gradually weakens. The high pressure then yields to a robust Pacific system. An initial warm front moves across the northern zones early Friday with a trailing cold front following during the afternoon. Gale force winds appear likely for the northern zones so have upgraded the Gale Watch to a Warning spanning from 8 am Friday through Friday night. The warning duration is probably a bit generous, but left some buffer in case models pickup on small scale features that may delay the front. Left the southern zones as a Gale Watch for now as latest models not as strong as yesterday. Seas also rise a tad to 10 to 12 ft, primarily consisting of steep wind driven waves. /mh && .PQR WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. PZ...Gale Warning from 8 AM Friday to 5 AM PDT Saturday for coastal waters from Cape Shoalwater WA to Cascade Head OR out 60 nm. Gale Watch from Friday afternoon through late Friday night for coastal waters from Cascade Head OR to Florence OR out 60 nm. && $$

000 FXUS66 KMFR 161020 AFDMFR Area Forecast Discussion National Weather Service Medford OR 320 AM PDT Thu Sep 16 2021 .DISCUSSION...Conditions will be dry and warm through early Friday afternoon, in what amounts to rather typical weather for late summer in our area. The rest of the weekend, however, will be much more atypical for mid September, with a significantly wet system expected to move through the region, producing plenty of rain, gusty winds, and much cooler temperatures. The models (both operational and ensembles) continue to trend slightly slower with the arrival of the front and precipitation. Thus, it`s looking more likely we`ll end up flat out dry through Friday afternoon. However we`ll see clouds and winds increasing as the day progresses. Moderate to strong winds are expected to develop east of the Cascades in the afternoon and early evening hours, and although models have also trended slightly weaker with the overall wind speeds, but winds could still easily reach between 25-35 kts, given the 700 mb flow. Blowing dust is very likely Friday afternoon downwind of Summer and Fossil lakes. In addition, relative humidities could still be on the low side which could result in enhanced fire weather concerns and this will be outlined in the fire weather discussion. Precipitation wise, it`s done deal the forecast could could get a significant amount of rainfall (the most in quite some time). The front has the markings of an AR (atmospheric river) with favorable upslope southwest flow which will lead to enhanced precipitation rates for the south Oregon coastal mountains and coast from Cape Blanco south. There remains some uncertainty, mainly with the aforementioned timing, but also in regards to the exact location of the main belt of moisture, with the EC ensemble trending slightly farther north than the GEFS members. Precipitation will arrive as an Atmospheric River event, and although not as warm-sourced as a "Pineapple Express," the moisture profile is impressive (IVTs, a measure of moisture transport, are reaching values well above the 99th percentile for this time of year as the main belt moves onshore Saturday). Rain will push into the area late Friday evening in Coos and Douglas counties, then gradually spread to the Cascades overnight, before reaching the rest of the forecast area during the day Saturday. The heaviest precipitation is expected to occur Friday night through Saturday afternoon, with the coastal mountains in southwest Oregon, the Cascades, and the north coast likely to see significant rainfall amounts. Rainfall amounts will be less elsewhere, but still considered significant in the Umpqua Basin, east of the Cascades (especially in the northern Half of Klamath and Lake counties), and within the Rogue and Illinois valleys. Keep in mind, this much rain in one go could produce some concerns with run- off, especially over area burn scars where soils are not receptive to moisture. With area river levels low, mainstem river and stream flooding is not expected, but smaller drainages and areas downslope/valley from recent wildfires could be susceptible to increased flows and debris. Gusty winds will be a concern once again on Saturday and the data supports even stronger winds aloft (700mb winds between 35 and 50 kts Saturday afternoon and early Saturday evening, which would most likely allow winds to reach advisory criteria east of the Cascades, especially over the higher terrain, including the Summer Lake area and portions of Modoc and southern Lake counties. The frontal system will continue to push southeast out of our area Saturday evening, but an upper trough will dig in behind it and we`ll continue to see scattered showers Saturday night through Sunday afternoon just about everywhere. This upper trough is rather deep, and will usher in a colder air mass aloft and this along with surface heating could result in isolated thunderstorms from the coast to the Cascade crest in southern ORegon, and over the Modoc in northern California late Sunday morning into Sunday afternoon. The upper trough axis will move through and set up east of our area Monday morning with showers gradually decreasing. The operational ECMWF and GFS dry things out pretty quickly overnight Sunday into Monday, but some light precipitation remains possible with the ongoing onshore flow, so we`ll stay the course and keep a slight chance of showers Monday morning north of the Umpqua Divide, northern Cascades and portions of Lake and Klamath County. Otherwise dry weather will return Monday as the upper trough departs and an upper ridge builds in overhead. With clearing skies, widespread areas of frost or freezing temperatures are possible east of the Cascades during the early morning hours, but otherwise, the region should see dry conditions early next week, with temperatures warming back to near normal values. In the last couple of cycles, the operational GFS and EC, along with many of their respective ensemble runs, have begun to resolve another trough arriving mid to late next week. Despite strengthening the prospective system in the latest run, the moisture profile appears much weaker than this weekend`s event. Given the wide spread of solutions and the lack of confidence, have kept precipitation chances modest, but trended temperatures a bit cooler for the rest of the forecast term, given the likelihood of lower heights aloft. -BPN && .AVIATION...16/06Z TAFs...Conditions are expected to remain VFR through Thursday afternoon, except for areas of MVFR/reduced visibility due to wildfires. Smoke will be thickest during the overnight into Thursday morning, and from eastern Douglas County and Siskiyou County across the Cascades into Klamath, Lake, and Modoc counties. An area of IFR stratus is expected to develop at the coast north of Cape Blanco late Thursday evening. -DW && .MARINE...Updated 200 AM PDT Thursday 16 September 2021...Gale force north winds will continue south of Cape Blanco and beyond 3 nm from shore until 11 am. Wind gusts could reach up to 45 knots between 10 to 20 nm from shore. However, most gusts should be around 35 to 40 knots. In addition to gales, very steep and hazardous seas will also persist south of Cape Blanco into Thursday morning while seas remain steep and hazardous to smaller craft between Florence and Cape Blanco. A fairly strong front for this time of the year will move across the waters Friday through Friday night and will likely result in small craft advisory south winds and steep seas, especially for the waters north of Cape Blanco. West-northwest swell builds into the waters Saturday through Sunday with elevated seas while low pressure creates unsettled showery conditions. Swell dominated seas are then expected to slowly diminish early next week. -DW/Smith && .FIRE WEATHER...Updated 200 AM PDT Thursday 16 September 2021... Relatively quiet, but typical late summer conditions are expected through Friday morning. East to northeast winds will be gusty over the ridges of southwest Oregon and western Siskiyou County this morning, but recoveries should be somewhat improved over those of the previous night. Low humidities are forecast once again Thursday, but winds will be weaker. A significant weather change is expected this weekend with the arrival of a strong, wet cold front and a deep trough that is likely to produce much cooler temperatures and widespread precipitation through the weekend. Gusty south to southwest winds are expected along the coast and east of the Cascades ahead of the front on Friday afternoon, but fortunately, humidities should rise enough to prevent most areas from reaching Red Flag criteria, with the exception of southeast FireWX zone 625, where critical conditions could be reached for an hour or two along the ridges as the winds pick up Friday afternoon. A Fire Weather Watch remains in effect for this scenario, but as forecast conditions are marginal, further evaluation is needed. Confidence remains high for a good dose of much-needed precipitation, which should begin along the coast Friday night, spread to the Cascades by Saturday morning, then to the rest of the forecast area through Saturday evening. Once the front passes late Saturday, the upper level trough will swing overhead, and showers are then expected through Sunday evening. A stray thunderstorm is not out of the question, especially along the coast in Douglas County, and along the Cascades crest. Wetting rains are expected for almost all of the area, with significant rainfall amounts possible along and west of the Cascades. This also means that debris flow/mudslides are possible in the most exposed portions of burnscars and though a low (~10%) probability of occurring, it is something we will be watching for. I am hesitant to use the term "season-ending event" with this system, but the rain will make a significant dent in the season. While wetting rains are likely, and fire weather conditions should be much improved, ridging and dry conditions will be quick to return on the backside of the system early next week. Also, there are indications of some gusty east winds, especially over the ridges and the usual downslope locations Monday night into Wednesday, and as a result, fire weather concerns may quickly bounce back despite the rains. That being said, another wet front is possible mid to late next week, although the exact nature of the system remains uncertain at this time range. -BPN/Miles && .MFR WATCHES/WARNINGS/ADVISORIES... OR...Fire Weather Watch from Friday afternoon through Friday evening for ORZ625. CA...None. Pacific Coastal Waters...Small Craft Advisory until 5 AM PDT Friday for PZZ356. Gale Warning until 11 AM PDT this morning for PZZ356-376. Hazardous Seas Warning from 11 AM this morning to 11 PM PDT this evening for PZZ356-376. Small Craft Advisory until 11 PM PDT this evening for PZZ350-370. Small Craft Advisory from 2 PM Friday to 5 PM PDT Saturday for PZZ350-370. Small Craft Advisory from 11 AM this morning to 5 AM PDT Friday for PZZ376. $$

000 FXUS66 KEKA 161214 AFDEKA AREA FORECAST DISCUSSION National Weather Service Eureka CA 514 AM PDT Thu Sep 16 2021 .SYNOPSIS...A gradual cooling trend will continue into the weekend. Beneficial rain is expected to spread across the area Saturday into Sunday, with the heaviest rains expected along the North Coast. && .DISCUSSION...Friday`s approaching upper level low has the potential for 1 to 2 inches of precipitation in the Northern most portions of the CWA (Del Norte) and gradually less accumulation towards the southern portions (Mendocino and Lake). Integrated Water Vapor Transport values are above normal for standard anomaly, according to situational awareness-NAEFS. Other guidance by NCEP suggest that the PacNW is on the receiving end of an Atmospheric River, albeit slight for EKA. This could be a sign of more to come if we are headed for a Pacific cold episode, LA Nina. Rain rates do not appear to be substantial enough to begin debris flow for local burn scars at this time. McCash and Monument fires will hopefully benefit from this weekends precipitation. Interior temperatures are expected to be in the mid 70s by Sunday. Strong onshore moisture transport will probably generate a deep and robust marine layer. Southerly flow over the weekend however will likely cap its inland extent. Rain will bring cloudy weather for the interior, but may help clear out stubborn valley smoke. Early next week, clusters generally show a weak ridging building into the area, though the exact timing varies wisely with some moving the trough out quickly Monday and others having it linger over the west until Wednesday. In any case, interior high pressure behind the trough looks to generate an offshore wind event early next week. The GFS show this scenario particularly strongly Monday night. This would lead to clear, breezy, and dry conditions. && .AVIATION...Coastal stratus has mostly been confined to the Mendocino coast this morning. However, some patchy radiational fog has developed near KCEC, and more may form near KACV before sunrise. This should be short-lived...with mostly VFR conditions expected today. Winds will be mostly light. Low clouds have spread up the Russian River Valley to KUKI. Expect these clouds to erode with daytime heating later this morning. /SEC && .MARINE...Northerly gale force gusts will continue through this afternoon across the northern outer waters and around Point Saint George. Winds will decrease tonight and Friday, then become southerly ahead of an approaching front by the weekend. Gusty northerlies will return by early next week. Have extended the Gale Warning for the N outer waters and the Hazardous Seas Warning for the N inner waters through mid-afternoon. Have also extended the Small Craft Advisory for the S inner waters through early Friday morning. /SEC && .FIRE WEATHER...Fire weather conditions have eased a bit. Winds remain modest and terrain driven. The cooling and moistening trend will continue. Minimum humidities are expected to improve over the next couple of days with minimum RH raising to the upper 10s and low 20s. Recoveries will vary between moderate and poor at ridge level. Temperatures will stay relatively seasonable. Some elevated northwest winds are expected in front of the trough on Thursday into Friday perhaps aiding in ventilation, though current guidance suggest minimal mixing to the surface. Otherwise, modest terrain winds are expected. Chances are looking consistently favorable for wetting rain this weekend, particularly in the northern half of the area. Elevated southerly winds look to mix closer to the surface as a cold front approaches the are. Winds will shift southerly late Friday and increase as the front approaches Saturday. NBM 1D viewer show upper elevation gusts touching the 20 mph range, mostly in northern zones. Rain following these winds should dampen any fire weather concerns. Offshore flow is possible behind the trough early next week, but the exact magnitude of this flow is highly uncertain. The GFS currently shows this pretty strongly late Monday late, bringing dry, breezy conditions to the area. && .EKA WATCHES/WARNINGS/ADVISORIES... CA... None. NORTHWEST CALIFORNIA COASTAL WATERS... Gale Warning until noon PDT today for Pt St George to Cape Mendocino 10 to 60 nm. Small Craft Advisory until midnight PDT tonight for Cape Mendocino to Pt Arena out 10 nm. Hazardous Seas Warning until 3 AM PDT Friday for Cape Mendocino to Pt Arena 10 to 60 nm. && $$ 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

000 FXUS66 KMTR 161142 AFDMTR Area Forecast Discussion National Weather Service San Francisco Bay Area 442 AM PDT Thu Sep 16 2021 .SYNOPSIS...Cooler but seasonable conditions will prevail through the end of the week. A deepening marine layer will move inland each night with seasonably warm weather near the coast and bays. As a trough approaches the West Coast this weekend, temperatures will dip below normal. Rain is looking more likely late Saturday into Sunday. Offshore wind event still looks possible Monday into Tuesday with warming temperatures. && .DISCUSSION...as of 03:26 AM PDT Thursday...Satellite imagery is almost a mirror image from last night - widespread stratus blankets the coast and inland valleys. Profiler data shows the marine layer has actually deepened and is near 2,000 feet. The deeper marine layer has limited fog potential this morning. Not seeing any reports of dense fog. However, the deeper marine layer may lead to some mist on some windshields. Numerous heat signatures are also visible across far NorCal and more prominent ones in the S Sierra from ongoing wildfires. No notable changes to the overall forecast through Friday. Night and morning clouds will be common with inland sunshine. The cooling trend the last few days will continue as well. Highs will be seasonably cool with highs in the 60s/70s coast and 70s/80s inland. The much talked about pattern change for the upcoming weekend is still on track. The disturbance lurking at the end of the Aleutian Islands will continue its eastward trajectory. The eastward push will be enhanced by a 180kt jet. The longwave pattern shows the disturbance deepening and moving into the PacNW on Friday. Quickly on the backside of this upper low another low pivots eastward and eventually rounds the base of the broader upper trough Saturday into Sunday. This feature will bring a front through the state ushering in some wetting rains. Rain chances rapidly increase along the OR/CA border early Saturday and then slowly progress southward. Current forecast has a few showers possible over N Sonoma by Saturday afternoon. More widespread chances for showers increase by Saturday evening north of San Jose. Shower chances will continue through Sunday afternoon and again mainly north of San Jose. A few showers may make it south to near Monterey Bay, but confidence is low. Rainfall amounts will still be rather low for the Bay Area despite the high PWATs. 0.05 to 0.20" for North Bay. Elsewhere amounts will generally be a few hundredths. If two tenths does fall across the North Bay this will be the most rainfall since last spring for a few locations. Rain chances end by Sunday evening. Behind the departing system high pressure begins to build into the Great Basin. As we approach fall this pattern is not that uncommon. The inland high pressure and coastal low pressure will lead to offshore flow. Models still show two pulses of offshore flow Sunday night and Monday night. Winds will be strongest over the N and E Bay higher terrain. How strong will it be? Still far out for specific details, but it does appear to be the first good offshore flow event. Needless to say, but it will be watched closely to see if a Fire Weather Watch will be needed over the weekend. && .AVIATION...as of 04:42 AM PDT Thursday...For the 12z TAFs. Widespread stratus across the Bay Area. Most terminals are under IFR conditions, with a few elevated cigs for MVFR conditions. Chances for patchy fog were removed from the TAFs given the continued deepening of the marine layer. Clouds will retreat to the ocean between 18Z and 19Z. VFR conditions Thursday afternoon with onshore breezy winds. MVFR cigs will return Thursday night with the chance for conditions to lower to IFR levels early Friday morning. Vicinity of KSFO...The terminal is surrounded by IFR cigs, yet a gap in the clouds sit over the immediate terminal. A TEMPO group was added for the chance the clouds fill in early Thursday morning, but there is decreasing confidence it will fill in. Clearing is expected after 18Z. VFR with winds up to 15 knots Thursday afternoon. While clouds move back into the bay Thursday evening, VFR conditions prevail before clouds fill in late for MVFR cigs early Friday morning. KSFO Bridge Approach...Similar to KSFO. Monterey Bay...IFR conditions. Cigs will clear late, around 19Z. VFR conditions briefly Thursday afternoon with onshore winds. Another night of early return at MVFR conditions lowering to IFR conditions later in the TAF period. && .MARINE...as of 02:33 AM PDT Thursday...Breezy northwest winds with increasing gusts over the northern waters. Chances for showers increase over the weekend as a cold front approaches Northern California. Wind driven seas prevail with a weak, long period southerly swell through the forecast period. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tday...SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...Pt Arena to Pt Reyes 0-10 nm from 3 PM && $$ PUBLIC FORECAST: MM AVIATION: DK MARINE: DK Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea

000 FXUS66 KOTX 161058 AFDOTX Area Forecast Discussion National Weather Service Spokane WA 358 AM PDT Thu Sep 16 2021 .SYNOPSIS... Morning low temperatures will tumble into the 30s and 40s under mostly clear skies. A Freeze Warning is in effect for the valleys of northeast Washington and far north Idaho, and areas of frost will be possible over the Palouse, West Plains, and northern portions of the Columbia Basin. The arrival of a wet frontal system late Friday will lead to a rainy and breezy weekend. && .DISCUSSION... Thursday: Water vapor satellite is revealing our cold upper level trough swinging through the northern third of Washington early this morning. Carving out a positively tilted trough as it shifts east into Idaho, the cold airmass will sink into eastern Washington, northern Idaho, and over into western Montana. Morning temperatures are on track to reach near or at freezing for many northern valley areas and in the mid to upper 30s elsewhere. The Metro area of Spokane-Coeur d`Alene should remain in the mid to upper 30s and be spared any frost hazard, however many other outlying areas will see frost or some light freezing conditions. We`re nearing the end of growing season for many locations. Friday: Behind the cold trough, we`ll see some mid-level warm advection and drying in between systems on Friday. Pre-frontal winds will begin to increase out of the south before the frontal passage early Saturday. The onset of precipitation into the Cascades and western Washington will take place during the day Friday and we may begin to see accumulation along the Cascade Crest and eastern slopes by Friday afternoon. Saturday: Frontal Passage Gusty Winds Analyzing the ensemble winds with the frontal passage early Saturday morning, 850mb winds look like they will strengthen and max out between Midnight and 6 AM with another very strong period from 6 AM through noon. The core of the strongest winds will focus from east of Portland, OR around the southern end of the Cascades and into the Columbia Basin towards northeast Washington. Having been watching the model guidance the last several days, this is the strongest model run of the last 4 days. This would suggest the frontal passage will be quite strong and fast. The timing of the strongest winds during the overnight hours when the boundary layer has decoupled doesn`t bode well for strong winds overnight, however as we`ve seen in previous early morning wind events, we may be able to quickly mix down some of this wind before all of the energy is absorbed by the stratiform rain. MOS and point-ensemble wind guidance would suggest just some breezy to gusty winds are likely Saturday, 20-25 mph. Stratiform Rain Precipitable water anomalies amongst the ensemble tables continue to advertise 150-200% of normal. This swath of moisture from the conveyor belt of moisture in the eastern Pacific will set the stage for a prolonged wet period of weather for the PacNW. In an area that has not seen much in the way of measurable precipitation for the last several months (outside of a few days in late Aug measuring 0.20-0.30" at select sites in eastern WA), this event looks like it could bring a significant amount of rainfall to (at least) eastern Washington and northern Idaho. Models have been in disagreement on just how much rainfall certain areas will receive. Some models have struggled likely due to the lack of training from no recent precipitation to base off. That aside, the strength of the front should provide for a few periods of heavy rainfall in the eastern Cascade slopes where we have some very fresh and higher intensity burn scars. Debris flows and rock slides will likely be common and something we need to continue to monitor. Next, the Basin and Palouse look to receive pretty impressive (for these areas) amounts which should be quite beneficial to agriculture communities. In eastern Washington and the northern Panhandle, localized flooding and ponding may be common with brief intense downpours, however the entire event looks to be more stratiform vs convective. The bottom line: a long duration, widespread rain event, heavy at times, will bring beneficial precipitation to the region and likely debris flows and rock slides near recent burn scars this weekend. /Dewey Sunday: The Inland Northwest can expect widespread shower activity through the day. Current models have kept the region under decent PWATs compare to other runs as the system has slowed over the region. Areas can possibly receive up to another few tenths of an inch by Monday morning. The chance for thunderstorms has spread from the northern mountains and into portions of the Columbia Basin as instability has increased in the area for late Sunday morning through the early afternoon. Higher rain rates in thunderstorms could produce flooding issues if over recent burn scars. Highs expected to be in the 60s. Lows will be in the 40s for most. Again, locations in the northern mountains could dip to near freezing overnight. Monday through Wednesday: A ridge builds off the coast and stops the moisture flow into the region. Chance of showers for the region will decline through the day and clear out by Monday night. Highs for the day will in the 60s. The clearing skies and stable cooler northern flow will bring cold temperatures of around 35 into portions of the Basin. Another trough is expected to bring another round of showers to the region midweek but there is low confidence on timing and moisture. It is steering toward a mountain shower event for the region. /JDC && .AVIATION... 12Z TAFS: Light winds are expected through the day and into the evening today (Thursday) for the airfields in eastern Washington and north Idaho. A dry air mass will result in mostly clear skies and low chances for early AM fog developing. Increasing clouds late this evening over the Cascades ahead of a front moving through late Friday. /Dewey && .PRELIMINARY POINT TEMPS/POPS... Spokane 67 44 68 51 62 47 / 0 0 10 40 80 70 Coeur d`Alene 65 42 67 51 61 47 / 0 0 10 40 80 70 Pullman 64 39 71 48 62 43 / 0 0 0 20 70 70 Lewiston 71 46 79 57 70 53 / 0 0 0 10 60 60 Colville 68 38 65 42 61 40 / 0 0 20 70 80 80 Sandpoint 63 36 62 47 56 44 / 0 0 20 50 90 80 Kellogg 63 45 68 54 61 48 / 0 0 10 20 80 80 Moses Lake 68 45 69 51 62 46 / 0 0 10 50 70 50 Wenatchee 68 54 66 57 63 52 / 0 0 30 70 70 50 Omak 71 48 66 53 66 49 / 0 0 30 80 60 50 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Frost Advisory until 8 AM PDT this morning for Idaho Palouse- Northern Panhandle. WA...Frost Advisory until 8 AM PDT this morning for Central Chelan County-Spokane Area-Upper Columbia Basin-Washington Palouse- Western Okanogan County. Freeze Warning until 8 AM PDT this morning for Northeast Mountains-Okanogan Highlands. && $$

000 FXUS66 KPDT 161457 AFDPDT Area Forecast Discussion National Weather Service Pendleton OR 757 AM PDT Thu Sep 16 2021 .UPDATE...Weak upper ridging over the region today will provide mostly sunny skies and light winds. However, temperatures will be on the cool side compared to Wednesday due to a northwest flow trajectory on the east side of the upper ridge and much cooler temperatures to start out with this morning than Wednesday. High temperatures today will be about 10 degrees cooler than Wednesday, with maximum readings on the upper 60s to lower 70s in the lower elevations, and 50s to 60s in the mountains. The upper ridge will flatten as it moves to the east tonight and is replaced by a westerly flow aloft and then a southwest flow by Friday evening. The next weather system to move into the region has slowed down and the precipitation is now not expected until about 06Z-12Z Saturday morning over the Cascades, and then over the rest of the forecast area by Saturday afternoon. The upper jet will be almost parallel to the initial cold front which usually means slow progression of the frontal precipitation, which will result in more of it over an area. The ECMWF is wetter than the GFS with this system, and the GEFS/ECMWF ensembles are in good agreement with the deterministic models with this system. Precipitation amounts through the weekend will range from about just over a half inch over the Lower Columbia Basin to as much as 1-2 inches in the Blue and Wallowa Mountains, and 1-3 inches in the Cascades, especially near the crest. There will be a period of Breezy conditions with moderately low RH`s on Friday before the onset of the precipitation, but the combination of wind and RH is not expected to reach critical fire criteria. Current forecast looks good and updates will not be needed this morning. 88 && .PREV DISCUSSION... /issued 243 AM PDT Thu Sep 16 2021/ SHORT TERM...Today through Saturday night...Dry westerly flow aloft will become southwesterly on Friday through Saturday as an upper trough develops off the PACNW coast. Today will be pleasant with mostly clear skies and cool temperatures. Highs will be in the 60s to lower 70s. It will be quite cool tonight with lows in the 30s in the mountains and lower to mid 40s lower elevations. As the flow turns more southwesterly on Friday temperatures will warm up and be about 5 degrees warmer than today. Rain will slowly spread east of the Washington Cascades during the day Friday and continue eastward Friday night and Saturday. ECMWF Extreme Forecast Index is indicating the potential for high QPF values compared to climatology especially along the Cascade east slopes where 1 to 3 inches of rain is possible. However when Sunday`s QPF is included (discussed in the long term discussion) many areas may see a months worth of QPF with this storm system. For example the mean GEFS plume for Pendleton is indicating over half an inch of rain compared to a monthly normal for September of .53 inches and the plume for Redmond is indicating more than double the monthly normal of .37 inches. This rain will primarily be beneficial and falling at moderate rates. Thus widespread flooding is not expected. However the situation will have to be monitored through the weekend especially over the burn scars. 78 LONG TERM...SUNDAY THROUGH WEDNESDAY...The extended period begins in the midst of a strong upper level trough that will continue to slowly pass through the Pacific Northwest on Sunday before exiting to our east on Monday. This system will bring widespread showers, breezy conditions, and cooler temperatures for Sunday. Additional rain amounts on Sunday range from less than a quarter of an inch for the Lower Columbia Basin, 0.25-0.5 inch through the foothills and eastern slopes of the Cascades, and 0.5-1 inch through the Cascades and the Blues. Temperatures will also be bottoming-out Sunday into Monday morning as Sunday`s highs will peak in the upper 50s to mid 60s and plummet into the upper 30s to upper 40s overnight into Monday morning. Winds will be greatest through Central Oregon and through the Eastern Gorge as 20-30 mph gusts will be possible Sunday afternoon/evening. The trough axis moves into Central Montana by Monday morning, allowing a ridge to build in its wake across the Pacific Northwest. This will allow a return to drier, warmer, and more calm conditions as gusts stay between 10-15 mph on Monday. Temperatures will also be slowly increasing through the workweek, as highs will be back into the low 70s by Wednesday across the Lower Columbia Basin. The ridge exits east Wednesday morning as winds increase ahead of another dropping upper level trough. Significant model differences exist with this system, as timing ranges from Wednesday morning (GFS) to Wednesday evening (ECMWF). However, models are all picking up on this feature and primarily highlight areas at elevation over the Cascades and the Blues to be the only recipients of rainfall. Guidance is still slowly coming in agreement with the tail end of the weekend system, but the ECWMF is still slightly more flat and faster on Sunday. This leads to a ECMWF outcome that is a touch drier and breezier than that of the GFS. However, the ECMWF EFI highlights Sunday as being an unclimatologically wet day, especially along the Cascades and through the east slopes. This shows confidence in the event, and also hints at the potential for rain amounts possibly needing to be increased slightly as we near the end of the weekend. The timing discrepancy between models is evident when viewing the 500 mb EOF pattern for Sunday, as 68% variance exists between ensembles relating to timing and only 12.5% variance correlates to the strength of the trough. Monday is similar, but is 52% related to timing and 24% regarding strength. This helps to give more confidence in rain totals and wind speeds, but the initiation and duration of these effects are still in question, albeit slight. The cluster phase space continues to show more confidence in the GEFS, as the deterministic/ensemble mean is closer to one another, in the same quadrant, and overall ensemble spread is much tighter both Sunday and Monday. One thing to note is that several ensemble members are hinting at a deeper trough developing Sunday and Monday, which could lead to slightly more precipitation than currently expected. Guidance diverges drastically behind this system on Tuesday and Wednesday as the ridge builds. The ECMWF builds a stronger ridge than the GFS, which has been the case recently, and holds off the incoming trough until Wednesday evening versus Wednesday morning as with the GFS. As a result, the GFS incurs a stronger trough and wetter conditions through the mountains than the ECMWF, since it does not have to break down as strong of a ridge. This also allows the system to move in quicker with the GFS outcome. Currently, confidence resides more in a GFS-heavy forecast through the midweek. This is based on the previous system`s scenario and the ECMWF deterministic and ensembles being less in line than the GFS both Tuesday and Wednesday. The cluster phase highlights this as the ECWMF deterministic for both days is rather far away from the ensemble means, origin point, and even individual ensemble members. 75 AVIATION...12Z TAFs...VFR conditions currently across all sites, which will stay the course through the period. Weak ridging occurs today in order to allow for clear skies and calm winds. Some high level clouds possible for YKM/PSC this morning, but should break up by noon. 75 && .PRELIMINARY POINT TEMPS/POPS... PDT 67 41 77 51 / 0 0 0 10 ALW 70 47 78 56 / 0 0 0 10 PSC 71 43 76 59 / 0 0 0 20 YKM 69 42 70 50 / 0 0 20 60 HRI 71 42 78 56 / 0 0 0 20 ELN 68 43 68 49 / 0 0 30 70 RDM 67 36 79 49 / 0 0 0 20 LGD 68 37 80 52 / 0 0 0 10 GCD 73 43 84 51 / 0 0 0 0 DLS 73 49 77 60 / 0 0 10 60 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...None. WA...None. && $$ SHORT TERM...88 LONG TERM....75 AVIATION...75

000 FXUS65 KREV 160933 AFDREV Area Forecast Discussion National Weather Service Reno NV 233 AM PDT Thu Sep 16 2021 .SYNOPSIS... Plan on quiet weather with warm temperatures through Friday. An early season storm will bring periods of gusty winds with increased fire danger and much cooler temperatures this weekend. Some light rain showers are expected by later this weekend. && .DISCUSSION... Warm days with cool nights to continue through the end of the work week along with afternoon and evening breezes, especially Friday. Smoke and haze will be lingering about as wildfire activity persists. Big changes are still on track for the weekend with a strong cold front dropping through the region. Here are the details: WINDS: Winds will start to pick up on Saturday, and even more so on Sunday with travel difficulties, choppy lake conditions, and areas of blowing dust possible. Winds will elevate the fire danger so fire weather watches remain in effect. Please see the fire section below for additional details. We`re expecting gusts 25-35 mph on Saturday and 30-45 mph Sunday, with locally stronger gusts 50+ mph in wind-prone locations. TEMPERATURES: Falling temperatures will have it feeling like fall! There will be about a 20 degree drop in daytimes highs on Sunday- Monday. The clouds, wind, and the potential for rain will contribute to making it feel even colder on Sunday. Frosts and freezes are possible for outlying rural areas and suburban valleys Monday through Wednesday mornings. Remember to protect your sensitive vegetation if your outdoor gardens are still flourishing. RAIN/SNOW POTENTIAL: Best chances for rainfall will be near and north of I-80 Saturday night into Sunday with lighter rain possible further south. Check back for updates as we dial in on the rainfall totals. A few flakes are possible above 10,000 feet, but accumulation is unlikely. If an NCFR develops or the cold front becomes convective, then we could easily see a short-lived, intense period of precipitation and lower snow levels than currently forecast. THUNDERSTORMS: There is a 15% chance for thunderstorms to develop in northeast California, possibly as far south as the Tahoe Basin, on Sunday as the cold and unstable portion of the low moves overhead. OUTLOOK FOR NEXT WEEK: Ahh the transition season...where the forecast models struggle with longer range forecasts. Simulations for next week are definitely falling prey to this time of year. The longer range ensemble cluster 500 mb heights continue to show variations between another trough dropping into the region and a strengthening ridge. Large NBM temperature spreads are indicative of the uncertainty as well. Still looking at low predictablity for the middle into the end of next week. -Edan && .AVIATION... Areas of haze from wildfire smoke will continue to impact slantwise VIS today; however, surface visibility should remain primarily VFR for terminals. For areas in the vicinity of the Dixie and Caldor fires, smoke may obscure some terrain. Light breezes with gusts up to 15-20 kts this afternoon and evening are expected to increase Friday with peak gusts 20-25 kts. Big changes are approaching for the weekend with strong winds, wind shear (above 2 kft AGL with at least pockets of LLWS), and turbulence likely. There is also increasing potential for rain and lowering CIGS/VIS. -Edan && .FIRE WEATHER... No major changes to the ongoing forecast. Strong cold front will bring big changes in the weather for the weekend. Winds begin to increase along the midslopes and ridges late Friday, with gusty winds forecast for Saturday and Sunday. Southwest to west wind gusts 25-35 mph on Saturday afternoon and evening will combine with very dry conditions east of the Sierra to produce areas of critical conditions. Fire Weather Watches remain in effect for for Saturday for areas near and north of US-50. Wind gusts will be a bit less (20-30 mph) and along with the higher humidity (20-30%), we refrained from a watch for the Tahoe Basin and fire zone 271 (western Lassen/Plumas). Saturday night winds will weaken for valley areas, but will likely remain elevated for the midslopes and ridges. Stronger winds are expected on Sunday with the latest ensemble guidance hinting at widespread gusts 35-45 mph and wind prone areas possibly reaching 50+ mph. The primary limiting factor for fire weather concerns will be the increasing humidity values and the potential for wetting rains. Areas near and east of US-395 and south of US-50 won`t be as fortunate and humidity values are not expected to increase until later in the day. Fire Weather Watch for gusty winds and low humidity remains in effect for those areas on Sunday. Another factor to consider with the increasing winds will areas of blowing dust and burned debris and/or ash. Visibility may be impacted in the vicinity of fires as any burned particles or ash become lofted by the strong winds ahead of the rain potential. Rain is looking increasingly likely for areas near and north of I-80 Saturday night into Sunday. Lighter showers will be possible for areas south of Interstate 80. High confidence continues for wetting rain (0.10"+) across northeast California into the Tahoe Basin and for northern Washoe County. There is still a bit of uncertainty with the amount of rain that will occur as this will rely heavily on the cold front`s ability to hold together as it drops southward. There is still a 15% chance for thunderstorms in northeast California and potentially as far south as the Tahoe Basin on Sunday. Just another factor to monitor which could threaten firefighter safety at ongoing wildfires. Solid cooldown behind the front with about a 20 degrees plummet in temperatures. Firefighter crews working overnight or sleeping outdoors will have to keep an eye on those colder temperatures as some frosts/freezes will be possible. Winds to shift N-NE behind the front on Monday. A major shift in winds will be a watch out situation for ongoing fires, especially since it can be a critical fire pattern for western Sierra slopes. -Edan && .REV Watches/Warnings/Advisories... NV...Fire Weather Watch from Saturday afternoon through Saturday evening NVZ420-423-429-458. Fire Weather Watch from Sunday afternoon through Sunday evening NVZ421-429. CA...Fire Weather Watch from Saturday afternoon through Saturday evening CAZ270-278. Fire Weather Watch from Sunday afternoon through Sunday evening CAZ274. && $$ For more information from the National Weather Service visit... http://weather.gov/reno

000 FXUS66 KSTO 161025 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 325 AM PDT Thu Sep 16 2021 .SYNOPSIS... Chances of moisture (not a bunch) increasing with best chances on Sunday. Cooling definitely on track with coolest day Sunday. Some gusty winds possible early next with temperatures slowly rising. && .DISCUSSION... Clear skies cover the region. Extensive stratus covers the Bay Area and profiler data indicates the marine layer has deepened to 2-2.5k ft. IR difference imagery shows stratus moving into the valley south of Travis, and narrowing temp/dew point spreads indicate potential for early morning stratus making it inland into the Sacramento region. Surface pressure gradients continue to mostly trend toward increased onshore flow, and most locales are seeing cooler temperatures compared to 24 hours ago. The cooling trend will continue today as a weak trough lingers over NorCal in the wake of the stronger system that moved through the PacNW yesterday. Highs today will be down several degrees compared to Wednesday, and increased onshore flow will bring higher humidity further inland across the Central Valley and foothill elevations. Temperatures will hold steady, or increase a few degrees, on Friday as short-wave ridging moves in ahead of the deeper weekend trough. Cooler weather is forecast to really take hold beginning Saturday as deeper southwest flow spreads across the region with the approaching trough. Highs will cool to around 5-10 degrees below average as onshore flow picks up. Gusty southwest winds are likely for much of the region, and particularly for areas along and east of the Sierra/Cascade crest. Humidity will be increasing in that area, so fire weather concerns will be mitigated somewhat. GEFS has slowed onset of precipitation to mainly late Saturday night and Sunday (now more in agreement with the EC ensemble). Mountain areas, especially north of I-80, may see QPF in excess of half an inch. Most of the valley will likely only see a few hundredths of an inch up to potentially around a quarter inch up by Redding. Hopefully consistency will continue to improve as the system get closer. && .EXTENDED DISCUSSION (Monday THROUGH Thursday)... The upper level trough that will bring us shower chances on Sunday will be pushing to the east into the Great Basin for the start of the extended period. This will bring an increased pressure gradient over NorCal as the upper level ridge builds in from the west. This will bring the potential for fire weather concerns on Monday as north and east winds pick up. Currently looks like gusts to 25-35 mph mainly over the northern Sac Valley and over the Sierra Monday morning. The main uncertainty with Monday is how dry humidity will get given the expected rainfall on Sunday. Short wave ridging builds in Tuesday with lighter winds and warmer temperatures. Models then dig a trough out of the Gulf of Alaska Wednesday into NorCal. There is a lot of uncertainty with this trough and ensembles do not have a good idea of timing and placement with it. Unlike the trough on Sunday there won`t be much moisture with it and the impacts will be minimal. Upper level ridging and warming temperatures build in behind the trough. -CJM && .AVIATION... Local areas of MVFR/IFR will be possible between 12 and 16z this morning into the southern Sacramento Valley due to FEW to BKN clouds at 008 to 015 as the marine layer pushes into the Valley. VFR conditions for all terminals by 17z. Local areas of MVFR near any wildfires due to smoke. Winds under 10 knots except through the Delta where gusts to 35 knots will be possible this morning. && .STO WATCHES/WARNINGS/ADVISORIES...None. && $$

000 FXUS65 KMSO 160856 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 256 AM MDT Thu Sep 16 2021 .DISCUSSION...Cooler air will continue to move into the region as the cold front progresses southeast, so high temperatures will be around 5-10 degrees cooler than yesterday. Warmer temperatures return on Friday due to southwesterly flow developing ahead of the upcoming trough. The slower progression of this weekend`s trough means there will be big differences from one side of the forecast area to the other. Moisture will reach northern Idaho and northwest Montana on Saturday, providing cooler, showery conditions, while north- central Idaho and west-central through southwest Montana will be warm and windy. There is high confidence for the trough to move through the region on Sunday and Monday, but still considerable differences in the specific timing and depth of the trough. The potential for a closed low is also uncertain with the latest deterministic models not showing the low closing off in Idaho or western Montana. Model consensus does show rain in northwest Montana by Saturday afternoon, north-central Idaho by Sunday morning, west-central Montana by Sunday afternoon, and Lemhi County through southwest Montana by late Sunday. Snow levels will lower Sunday night and Monday, and snow accumulations above 6500 feet are more likely. There is still potential for lower snow levels. If you are planning to be in the backcountry, please be prepared for cold and wet conditions. && .AVIATION...The terrain and a few valley locations have maintained wind overnight with a west to northwesterly pressure gradient being observed. The pressure gradient is forecast to relax some today but winds of 10-20 knots will develop by the afternoon. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...Frost Advisory until 9 AM MDT this morning Kootenai/Cabinet Region. ID...None. && $$

000 FXUS65 KBOI 160947 AFDBOI Area Forecast Discussion National Weather Service Boise ID 347 AM MDT Thu Sep 16 2021 .SHORT TERM...Today through Saturday night...Little change from previous forecast. Sunny, breezy, and cooler today behind cold front currently passing through Idaho zones. A little more smoke today in southern areas. Sunny and warmer Friday under flat ridging aloft ahead of approaching Pacific trough. The trough will reach the northwest coast Friday night and begin light rain in western Baker and Harney Counties early Saturday morning. Rain will advance east Saturday and Saturday night. Ahead of it Saturday will again be quite warm. By sunrise Sunday the leading edge of pcpn will be across Adams and Valley Counties in Idaho, and in eastern Malheur County. .LONG TERM...Sunday through Thursday...A broad upper level trough will bring a cold front and widespread showers to the region on Sunday. Snow levels will lower to 6500-7000 ft MSL as the core of the system moves overhead. Showers will continue into Monday afternoon as the system moves east. Temperatures will fall roughly 15-20 degrees below normal on Monday and Tuesday, providing our first taste of fall weather. Frosty conditions possible on Tuesday morning. A weak ridge will move across the area on Tuesday with slightly warmer temperatures before a another trough and cold front move into the area late Wednesday into Thursday. && .AVIATION...VFR. Mostly clear. Smoke layers increasing today, reducing visibilities aloft. Surface winds: generally W-NW 5-15 kt. Winds aloft at 10k feet MSL: W 15-25 kt decreasing to 5-10 kt by 00z/Fri. Weekend Outlook...VFR, breezy and increasing clouds on Saturday. Showers becoming widespread late Saturday and lasting into Monday with MVFR to IFR conditions, mountains obscured. Snow levels 6500- 7500ft. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...None. OR...None. && $$ www.weather.gov/Boise www.facebook.com/NWSBoise www.twitter.com/NWSBoise SHORT TERM...LC LONG TERM....KA AVIATION.....KA

000 FXUS65 KLKN 160909 AFDLKN Area Forecast Discussion National Weather Service Elko NV 209 AM PDT Thu Sep 16 2021 .SYNOPSIS...Warm and dry weather expected through Saturday. Some locally breezy conditions possible this afternoon, however, breezy to windy conditions are expected on Friday, especially across central Nevada. Saturday will see stronger winds across much of the region as well. A cold front will bring rain showers and more strong winds Sunday, with much cooler temps expected early next week in its wake. && .SHORT TERM...Today through Friday evening...Slightly cooler today, especially across the north, as a weak dry front eclipses the region. The upper level pattern will then transition back to more southwesterly flow tonight into Friday as weak cutoff approaches Cali coast, a stronger upper level low approaches PacNW, and a ridge builds off to our south and east. May see a slight uptick in mid to high level moisture, but dry and mostly sunny conditions will continue. Above normal temps continue with highs today in the upper 70s to 80s. Slightly warmer Friday with highs generally in the 80s across the whole region. Some locally breezy winds possible today, but winds will be breezy to windy on Friday, especially across central NV, as 700 winds increase in the southwest flow aloft. Some haze/smoke concerns could persist, but overall impacts have decreased as fire activity off to the north and west has diminished. .LONG TERM...Friday night to next Thursday Friday night and Saturday still look to be dry with overnight low temperatures mostly in the mid to upper 40s and colder valleys around low to mid 30s. Saturdays highs will be low to mid 80s. Winds will be SW and quite breezy by Saturday afternoon, trending lighter Saturday night yet likely remaining light to breezy across NW Humboldt county as the incoming cold front closes in. Weather will turn much more active Sunday as a trough and surface cold front begin moving into NW Nevada as early as late Saturday night. This may bring light isolated rain showers to portions of NW Humboldt county late Saturday night. Showers will spread across northern and central Nevada Sunday from NW to SE with slightly greater coverage across Humboldt and Elko counties as the frontal boundary traverses the region. Some mountain snow showers are also likely as colder air moves in behind the front, particularly Sunday night into Monday. Also expect breezy and gusty winds gradually turning from SW to NW in conjunction with the passage of the front. && .AVIATION...VFR conditions with mostly clear skies. Some high based cu possible this afternoon, mainly at EKO and ELY. Winds increasing this afternoon to 10-15kts with some higher gusts. Some lingering haze/smoke concerns possible, but little if any vis impacts expected. && .FIRE WEATHER...Warm and very dry conditions expected through Saturday, with Friday being the warmest day. Nighttime RH recoveries will also be low. Some locally breezy conditions expected today, with stronger winds expected Friday, especially across central NV. A Fire Weather Watch is in effect for fire zones 425-427 as wind gusts to 35 mph and min RH values 9-14 percent expected. Winds will once again be breezy to windy on Saturday as well. A watch will continue for fire zones 425-427, though the northern zones may also be affected. By Sunday, chances for precipitation increase in the northern half of the forecast area as a storm system from the Pacific Northwest dives to the southeast. Minimum RH values may be a little high in the north but central Nevada could see another day of critical fire weather conditions and we will need to keep an eye on this. The quiet weather is expected to return for Monday and Tuesday though temperatures will be much cooler. && .LKN WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Friday afternoon through Saturday evening for Central Nevada-Toiyabe-Northern Nye County-Mojave- White Pine and Northeast Nye Counties. && $$ 87/92/87/87