Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/20/22

Area Forecast Discussion
National Weather Service Gray ME
1032 PM EST Sat Feb 19 2022 .SYNOPSIS... Snow showers will diminish overnight with gusty northwest winds causing wind chills to fall below zero. High pressure builds in Sunday, then shifts offshore Monday allowing temperatures to climb above normal. A system will impact the region by mid-week with the potential for rain for most of the area with mixed precipitation possible for interior areas. High pressure will build into the region from Canada on Thursday, followed by low pressure passing off the New England coastline on Friday. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... 1030PM Update: Snow showers continue to weaken south and east of the mountains with only changes this hour being to match evening temperature/dewpoint trends. Overnight lows look on track with wind chills already below zero in the mountains...and in the single digits to the south and east. Bundle up out there this evening! 830PM Update: Band of SHSN along advancing arctic front has remained coherent as it moves south and east...and have updated the forecast for this over the next few hours as it brings a wind shift along with another round of low vsbys. Expect weakening of this band as it moves into the downslope regime south of the Whites. 710PM Update: Remaining snow showers departing with a secondary band noted south and east of KBTV which will make a run at the CT Valley as it weakens moving south. Updated PoPs for current radar presentation and matched up temperature trends /temps needed to boosted a bit/. No other significant changes at this time. 2030Z Update... Have updated the forecast based on latest radar imagery and mesoscale models. Snow showers and squalls will be reaching the coastline within the next hour in Maine followed by falling temperatures and low wind chills. Have adjusted pops this package as well as winds and dew points. Prev Disc...For the remainder of the late day and early evening hours, roads temperatures continue to remain relatively steady across the region. Pavement readings have remained mostly in the 30s across southern areas as cloud cover has thickened and lowered with cooler readings further to the north. The warmest layers are along and near the coastal plain and also over southernmost New Hampshire. This has implications for the potential for flash freezes across portions of the region as we head into the evening hours. Cold pavement conditions continue to the north. Spoke with local fire departments earlier today for the status of ice dams in New Hampshire. Reports indicate that most of the activity has settled down for the time being with colder temperature in place across the region, although rises have occurred in the Conway area per gauged reports and fire department reports. Will continue to closely monitor for potential river rises or flooding however, especially along the Sugar and Saco Rivers. The latest HRRR and SPC analysis continues to do a very good job depicting a line of snow squalls which were over central New York State from the mid afternoon hours, albeit trends have been to slow the timing of the line. Instability values and snow squall parameters suggest this line will cross through the region between 20Z-01Z from west to east, exiting the Midcoast region early this evening. Low visibilities, gusty winds, dangerous driving conditions and flash freezes may still occur. Snowfall rates, visibilities and QPF have been increased through this evening. Snowfall amounts could reach the 2 to 4 inch range across the higher terrain in the north as this system crosses the region. Overnight, conditions settle down by the mid to late evening hours with just some upslope snow showers in the favorable northwest facing higher terrain. It will still be windy for a portion of the night with GYX probability data plots indicating winds gusting to 25 kt. The same plots suggest a rapid decrease in the chance for precipitation during the evening after the passage of the convective snow shower and squall line. Temperatures bottom out in the single numbers below zero in the north tonight and single numbers above in the south. Winds will allow for wind chill values to drop to near 20 below zero in the north which is close to Wind Chill Advisory Criteria. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... Much more quiet conditions expected on Sunday with the near normal temperatures allowing for the threat of any ice jams to continue to diminish with time. It will be mainly sunny over southern areas where downslope conditions will persist. Mostly cloudy conditions expected over northern areas where some moisture will enter the region under an area of warm air advection over the periphery of the ridge. Winds will diminish during the afternoon hours as the strongest gradient shifts to the east. A southwesterly flow then develops over the region as the large ridge of high pressure exits off the Eastern Seaboard Sunday night. Warm air advection over the region will allow for temperatures to gradually rise during the overnight period which is reflected in the non-diurnal trends. && .LONG TERM /MONDAY THROUGH SATURDAY/... Monday, a weakening cold front will be advancing towards the area from the NW. The cold front will carry little moisture, but some snow showers will be possible across the western high terrain. The more important variable will be cold air advection associated with this front at the surface, as this could play a role in precip types come Tuesday afternoon. Monday night, the front attempts to continue across the eastern CWA. This is visible from temp advection at the surface, but the signal is more diluted in the low levels due to overrunning SW WAA. This comes as the once separate jets begin to merge across the southern Great Lakes. The GFS is strongest in keeping this cold air anchored at the surface, plunging the front through southern Maine. In addition, onshore warm air is also weaker and presents a CAD situation as precip begins overunning the area. This would result in a period of freezing rain inland before joining southern NH and coastal ME with all rain Tues evening/overnight. GEFS also displays a much weaker singular low pres across the Northeast vs. EPS bringing a stronger sfc low consensus through the eastern Great Lakes. As a result, ECMWF and GEM solutions keep this cold front bottled up to the north along the Quebec border, with a warmer rainy result outside of the higher terrain. Have kept precip types locked to rain or snow, but a mix may need to be mentioned in further forecasts if confidence increases in a freezing rain solution, particularly once NAM guidance is in range. A non-diurnal temp trend continues Tuesday night into Wednesday with rain overspreading the area. Low pressure will be tracking NE, with enough lift out ahead to potentially bring some enhanced precip rates. The more persistent stratiform precip should move NE quickly w/ the low, as showers taper over the area Wed and Wed night. With this warmup and potential rain Monday through Wednesday, will again need to be wary of ice movement amid runoff and snowmelt. High pressure takes over Thursday and Thursday night, before another disturbance approaches for Friday. A flatter, more progressive track presents a chance for snow for much of the area should the low stay to the south and track out to sea. Will need to pay attention to positioning of a deformation band north of the lows track, as well as any potential strengthening over the GoME. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/... Short Term... Summary: High pressure builds in through Sunday behind a departing cold front before moving south of the region Sunday night. Restrictions: Last of the snow squall activity will impact AUG and RKD through the next hour with brief LIFR/IFR VSBYS before conditions return to VFR through Sunday night. The only other exception to this will be some MVFR cloudiness this evening at HIE. Winds: Northwest winds 15g25kts will gradually subside after midnight back to around 10kts before shifting southwest during the day Sunday. Southwest winds will continue 5-10kts Sunday night. LLWS: No LLWS is expected through Sunday. Strengthening southwest winds aloft Sunday night will bring the potential for LLWS. Snowfall rates / character: Snow at AUG/RKD will be briefly heavy and not wet. Long Term...VFR expected Monday outside of some MVFR at KHIE w/ -SHSN. Clouds thicken and lower late Mon night into Tuesday with becoming IFR with snow changing to rain. SE winds increase and become SW overnight into Wednesday. Conditions trend VFR Wednesday evening with winds becoming W through Thursday. && .MARINE... Short Term...Bufkit profiles suggest mixing will rapidly be on the increase across the waters early this evening with the frontal passage. An abrupt wind shift to the northwest will occur and become aligned through an increasingly deep layer through the night. This will allow for gale force winds to continue during the overnight period. Strong cold air advection will add to the wind gust potential. Light freezing spray will develop with the cold air advecting over the waters. A narrow ridge axis will build over the waters Sunday, however the gradient will still allow for SCA thresholds to be exceeded. By Sunday night, winds will veer to the southwest as the gradient increases between a large ridge of high pressure off the Eastern Seaboard and a frontal system approaching from the northwest. Long Term...SCA conditions continue into Monday afternoon, at which both wave heights and winds will begin to slacken. Winds shift SE Tuesday afternoon, with some Gale conditions possible. Wave heights also respond increasing 4 to 7 ft through Wednesday. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...Small Craft Advisory until 7 AM EST Sunday for ANZ151-153. Gale Warning until 7 AM EST Sunday for ANZ150-152-154. && $$ SYNOPSIS... NEAR TERM...Arnott SHORT TERM... LONG TERM... AVIATION... MARINE...
Area Forecast Discussion
National Weather Service Spokane WA
346 PM PST Sat Feb 19 2022 .SYNOPSIS... A cooler and showery weather pattern is expected for the remainder of the weekend into Monday. Moderate to locally heavy snow accumulations are likely for the Cascade crest and the Idaho Panhandle mountains. The chance for valley accumulations will increase Sunday Night into Monday morning as colder air arrives. Bitter north winds will develop Monday and Monday night bringing a return of winter temperatures to our region. && .DISCUSSION... Today through Sunday: A Pacific cold front is sweeping across the region this afternoon from the northwest. A lack of deep layer moisture and strong westerly flow has kept the bulk of the precipitation with the front near the Cascade crest and Idaho Panhandle. Breezy winds will gradually subside this evening. Tonight into Sunday temperature lapse rates will increase as a cold pool at 500mb tracks over the region. This will result in an unstable atmosphere promoting showery weather. Moist, unstable, upslope flow into the Cascade crest will really ramp up the snow showers. This is even more true in the Puget Sound Convergence Zone with several mesoscale models showing Stevens Pass to be impacted for at least part of the night beginning this evening. The National Blend of Models is giving this location 20" of snow through Sunday afternoon. A Winter Storm Warning remains in place. With some continued mid level westerly flow models are showing the greatest focus of showers through Sunday over the Cascades and Idaho Panhandle. Snow levels will gradually lower to 1500-2500 feet by Sunday afternoon but the bulk of the accumulations should stay in the mountains. Lookout Pass as well as the Blue Mountains will likely be impacted by several inches of snow so have issued a Winter Weather Advisory for these areas. One caveat to the idea of mainly mountain snow through Sunday is the last couple NAM model runs which show a band of moderate to heavy showers developing in a west- east convergence band around Wilbur to Spokane/Coeur d`Alene Sunday morning which could yield a surprise band of wet snow accumulations. But with other models weaker or non existent with idea this solution carries low confidence. Sunday Night into Monday an arctic front begins to sag south into the region. Typically arctic fronts from the northeast follow a slower timing as the Rocky Mountain Divide slows the forward progress of the front. The 12z ECMWF is one of the slower solutions and followed this idea, which is close to the timing of the morning HRRR runs. The arctic air is expected to reach the North Idaho Panhandle Sunday night, before tracking into the Spokane area and Upper Columbia Basin Monday morning and then down into southern WA/Lewiston area by late Monday afternoon. Models continue to show an unstable atmosphere along and ahead of the front. Frontal forcing may produce a band of accumulating snow with the front with the highest threat over the Idaho Panhandle and eastern third of WA per ensemble data. But can not rule out some light snow with the front for any given area. Given most areas will have a threat of light snow have trended up POP`s towards the SREF. Gusty northeast winds will develop behind the front with models continuing to show the highest winds through the Purcell Trench of North Idaho, and across the Upper Columbia Basin. JW Monday night through Saturday: The Inland Northwest will be in a much colder, but drier pattern this period. A broad trough and north to northeast flow will draw in the drier arctic early this week. The flow will keep some snow chances going near the Cascades and Blue Mountain Monday night. The more notable feature will be the breezy to windy conditions. A tight northeast to southwest pressure gradient will contribute to this through Tuesday before slackening Tuesday night onward. Right now winds are forecast to be in the 15-25 mph range outside of the sheltered mountain valleys, with gusts of 30 to 40 mph. The forecast highs and lows from Monday night to Wednesday will be around 20 degrees below normal, meaning lows in the single digits and lower teens and highs in the upper teens to 20s. Combined with the aforementioned winds, we could be looking at some dangerous wind chills Monday night into Tuesday morning. This includes the north Idaho and northeast WA valleys, the Spokane/C`dA area, Palouse and the Upper Columbia Basin, where wind chills of -10 to -20 F may be seen. From Wednesday to Saturday the winds slacken and temperatures slow begin to moderate with the cold trough slowly losing its influence. It is not until Saturday that highs come closer to seasonal normals, but not quite make it there. An upper disturbance passing in the northwest flow will have to be monitored for possible snow chances around Thursday, but right now the risk is too low to include in the forecast. A better chance arrives next Saturday as a system approaches from the west, but there are still model disagreements on how quick the flow turns southwest to carry that system inland. /Cote` && .AVIATION... 00Z TAFS: Breezy to locally windy conditions are expected through early this evening behind a cold front. Showers will develop through the evening and overnight hours for the ID Panhandle and eastern third of WA. Given the convective nature and a potential area of mid level convergence for added lift around Spokane/Coeur d`Alene there is quite a bit of model differences regarding the coverage and intensity of the showers. The highest focus per ensemble data is expected on the Palouse into the LC Valley and ID Panhandle. Snow levels will be around 2000-3000 feet late tonight possibly dropping to 1500-2500 feet Sunday AM. JW && .PRELIMINARY POINT TEMPS/POPS... Spokane 31 40 24 27 7 21 / 20 40 40 60 0 0 Coeur d`Alene 31 39 23 25 6 19 / 40 60 60 60 0 0 Pullman 33 39 26 31 9 22 / 40 60 50 70 0 0 Lewiston 39 47 31 38 19 28 / 20 60 40 60 10 0 Colville 25 41 26 29 3 22 / 30 30 30 30 10 0 Sandpoint 31 37 20 23 6 18 / 50 50 60 50 0 0 Kellogg 31 36 21 24 3 14 / 80 90 80 60 0 0 Moses Lake 31 47 29 35 13 27 / 0 10 10 30 0 0 Wenatchee 33 46 31 34 13 23 / 10 10 10 40 10 0 Omak 26 44 25 33 11 25 / 0 20 20 20 10 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Winter Weather Advisory from 10 PM this evening to 10 AM PST Monday for Central Panhandle Mountains. WA...Winter Storm Warning until 4 PM PST Sunday for Western Chelan County. Winter Weather Advisory from 10 PM this evening to 4 AM PST Monday for Northeast Blue Mountains. && $$
Area Forecast Discussion...RESENT
National Weather Service Pueblo CO
306 PM MST Sat Feb 19 2022 .SHORT TERM...(This evening through Sunday) Issued at 304 PM MST Sat Feb 19 2022 Key Messages: 1)Warm and quiet the rest of today. 2)Critical Fire Weather conditions possible along southern I-25 tomorrow afternoon. Currently... Clear skies and warm temperatures continue across the CWA this afternoon. A few areas are seeing gusty winds, including some of our mountain passes and the far southeast plains, with SPD gusting to around 40 knots. Even so, conditions are still not quite meeting thresholds for fire weather highlights. Rest of Today-Tomorrow... Winds will die off a bit this evening as flow aloft turns more westerly. Low temperatures tonight will be slightly warmer than last night, with mid-high 20s over the plains, while the higher terrain and mountain valleys will still be seeing single digits. Skies are also expected to remain mostly clear. The warming trend from the previous several days will continue into Sunday, with high-40s to low-50s over the valleys, and high-60s to potentially low-70s possible over the plains, with the warmest temps expected closer to the KS border. RH will be a bit lower across the area than today, with values in most areas over the plains dipping below critical thresholds. When looking at the fire weather concerns for tomorrow, the limiting factor will be the wind. Most guidance kept sustained winds near or below 10 knots or so, with a few gusty areas appearing sporadically throughout the afternoon. However, a few of the models, including the latest HRRR and the NBM, pick up on some potential gap flow just east of the mountains over I-25. In accordance with these possible conditions, have hoisted a Fire Weather Watch over the southern I-25 corridor. Have left everything north of Pueblo County out of it for now, as gusty conditions appear spotty and inconsistent. These potential conditions will persist well into the afternoon and early evening, after which winds are expected to die off while RH recovers. .LONG TERM...(Sunday night through Saturday) Issued at 304 PM MST Sat Feb 19 2022 Key Messages: 1) Above normal warmth continues on Monday ahead of approaching cold front. 2) Critical fire weather conditions will be possible across the southeast plains Monday. 3) A return to winter-like weather early next week, with impactful mountain snows and much colder weather expected across southern Colorado. Will begin to see the next system to impact the region moving into the western CONUS early Monday, with a digging trough and southward moving cold air approaching the region. Associated cold front will be diving south during the day on Monday, though much of the plains now look to remain in the warmer air longer. Given the strength of the air mass dropping south during this time, would anticipate the front to quickly push south. However, it is appearing that some mid level energy will eject overhead on Monday and help with a developing low over the eastern plains. This will likely help keep the front to the north slightly longer, along with supporting a strengthening wind field. While not quite as warm as Sunday, another day of above normal warmth is expected over the eastern plains, along with continued fire weather concerns. It`s now appearing that falling dew points and RH values and increasing west southwest winds will support critical fire weather conditions over portions of the southeast plains Monday afternoon and could see the need for fire weather headlines with later forecasts. By late in the day Monday and especially Monday night, upper trough will continue to shift east and while cold front pushes south across the plains. This will shift focus towards the expected colder conditions next week, along with increasing snow chances over much of southern Colorado. Some potential for some stronger gusts with the FROPA Monday evening with some guidance hinting at the potential for these stronger gusts. At this time though, any gusts don`t appear to be overly strong or widespread. Snow will likely be ongoing across the Continental Divide Monday night, with some potential for snow along the Palmer Divide. Additionally, forecast sounding across the eastern plains do indicate some increasing low level moisture and low level omega post fropa. With a briefly lingering warm nose and lacking deep moisture, there would be some concern for light freezing drizzle over the eastern plains. Low confidence on this scenario, but will continue to keep a close eye on it. While still some uncertainty with the system`s evolution, there are features that continue to stand out. One is with the rather cold air mass that is anticipated to settle in, with guidance showing really cold 700mb temps in place through the middle part of next week. This will support well below normal temps over the CWA during that time, and possibly persisting through the end of the work week. Several nights during this time frame are anticipated to observe low temps near or below zero over much of southern Colorado. Also during this time, really low wind chills will be a concern and given how the system may unfold, it`s possible that some locations may see a longer period of values well below zero. Still continue to see signals for impactful snow over the higher terrain, especially across the southwest mountains, among varying guidance. Southwest flow really sets up out ahead of this initial main upper trough and then looks to continue out ahead of another approaching trough. While this setup will favor higher snow across the southwest mountains, other locations along the Continental Divide as well as the eastern mountains look to periodically observe favorable flow and synoptic support. Confidence with snow across the lower terrain is low, though still remains a distinct possibility. While accumulating snow will be possible across the lower terrain next week, it`s still too early to know exact amounts, impacts, and location at this time. Will continue to keep a close eye on this potential though, as some guidance is showing the possibility for multiple periods of travel impacts over the I-25 corridor and other main highways. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 304 PM MST Sat Feb 19 2022 VFR conditions are expected at KALS, KCOS, and KPUB over the next 24 hours. South to southwest winds gusting up to 30 knots will be possible later this afternoon over the far southeast corner of the state. && .PUB WATCHES/WARNINGS/ADVISORIES... Fire Weather Watch from Sunday morning through Sunday afternoon for COZ228>230. && $$ SHORT TERM...GARBEROGLIO LONG TERM...RODRIGUEZ AVIATION...GARBEROGLIO