Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/22/18

Area Forecast Discussion
National Weather Service Albany NY
1040 PM EDT Wed Mar 21 2018 .SYNOPSIS... A coastal storm will bring some snow south and east of the Capital Region tonight. Generally fair but chilly conditions will return for Thursday into Friday, although a passing upper level disturbance could bring some snow showers for Friday. && .NEAR TERM /THROUGH THURSDAY NIGHT/... ...Winter Weather Advisory for Dutchess and Litchfield Counties until 8 AM Thursday... As of 1040 PM EDT...The latest radar and observational trends combined with the most recent 3-km HRRR and NAM nest guidance support dropping the advisories in Ulster, eastern Columbia, and southern Berkshire Counties. We also collaborated with WFO BOX and OKX about converting the Winter Storm Warning for Litchfield County to an advisory. The low-level dry air with the north to northeast flow from high pressure over Hudson Bay continues to keep the pcpn echoes suppressed south and east of the I-90 corridor. The 00Z KALY sounding continues to show a slow and gradual moistening of the column with clouds near H700 or about 10 kft AGL. The PWAT has only risen to 0.28". The column finally moistened between 9-10 pm for snow at KPOU. A few light snow amounts have come in in southern Litchfield County in the 1-2" range. Please see our latest PNS. An additional 2-5" is possible with the heaviest amounts from Poughkeepsie-Torrington south and east. Further north, a coating to a few inches is possible. Some retooling of the PoPs and temps was done based on observational trends. Portions of the Capital Region north and west will received a few flakes or no snow at all. Lows tonight mainly in the upper teens to mid 20s northern areas, and mid/upper 20s central and southern areas. North to northeast winds will remain brisk, esp across southern areas where some gusts up to 25 mph could occur. For Thursday, some lingering snow showers may be ongoing through the morning across the Taconics, Berkshires, Litchfield Hills, and even the Capital Region, before decreasing in the afternoon. Some breaks in the clouds are expected to develop in the afternoon. It will remain quite breezy, with northwest winds gusting up to 25-30 mph at times. Highs should reach the upper 30s to lower 40s in valleys, with mainly lower/mid 30s across higher terrain. Weak shortwave ridging should build across Thursday night, allowing for some clearing to occur. Temps may fall off more than currently forecast due to decoupling, with current forecast lows in the teens to mid/upper 20s, although again, may be quite a bit lower in some areas. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... An upper tropospheric shortwave trough will remain over the Northeast Friday through Sunday morning with multiple pieces of shortwave energy slipping southward over the region. Limited moisture and lift will inhibit precipitation beyond snow flurries or a few passing showers over the weekend. The Adirondacks and higher terrain in southern Vermont could see up to a few tenths of an inch of snow accumulation over the weekend. High temperatures on Friday and Saturday will be in the low 30s to low 40s with low temperatures in the upper teens to mid 20s. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... The mean longwave trough over the Northeast will begin to weaken by the end of the weekend, as a high amplitude ridge builds into the Northeast from the west/southwest with temperatures moderating closer to late March seasonal normal readings. Sunday...A large sfc Canadian anticyclone /1040 hPa/ attempts to ridge in from north-central Quebec, as an upper level trough moves across the region with some isolated rain and snow showers especially over the higher terrain south and east of the Capital Region. The cold pool with the upper low will focus some instability showers tied to the diurnal heating based on the latest 12Z GFS/ECMWF/GEFS/CMC. H850 temps will be in the -8C to -10C range. Highs will run below normal by 10 degrees or so with upper 30s to lower 40s in the valley areas, and upper 20s to mid 30s over the higher terrain. Sunday night into Monday Night...A high amplitude ridge builds in from the Southeast through the Great lakes Region and into eastern Canada. The H500 ridge folds over into the Northeast and the Canadian Maritimes early in the week with a big cutoff cyclone off the New England Coast. H500 heights increase to 570 decameters over southeast Ontario and southern Quebec. Fair and cold or cool weather will persist with lows in the teens and 20s, and highs on Monday getting into mid 30s to mid 40s. Tuesday will be the transition day where temperatures get closer to normal readings with the sfc anticyclone anchored over northern New England and the East Coast. A cold front will be approaching from the northern Plains and western Great Lakes Region. Highs reach the upper 40s to around 50F in the valleys with abundant sunshine, and upper 30s to mid 40s in the mtns. Tuesday night into Wednesday...Some differences with the medium range guidance and the ensembles on the timing of the break down of the ridge over the Northeast. A cold front, and a sfc low will be approaching from the Midwest and Great Lakes Region. We slowly increased a slight chance to chance of rain/snow showers late Tue night into Wednesday with seasonable temps for the forecast area. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... Coastal storm continues to spin offshore, sending snow bands north and west across southern New England and southern New York. Moisture associated with the storm is battling a stout feed of dry air from the north, and currently the dry air is winning out. Snow potential at KALB/KGFL is little to none with VFR conditions prevailing under a midlevel stratus deck. Snow potential remains uncertain at KPOU/KPSF. Current thinking is that the column will eventually saturate enough to support snowfall at KPOU, but the timing was pushed back a few hours. Once snowfall begins, visibility will likely deteriorate quickly to IFR within an hour or two. The timing of the onset of snowfall remains uncertain, making this a highly challenging forecast. Even less confidence for snow potential at KPSF, but enough evidence to maintain a mention of MVFR snow showers with a TEMPO for IFR. Conditions improve at KPSF/KPOU late tonight as the coastal storm pulls away, with drier air raising ceilings to VFR late tonight or early Thursday morning. Winds will remain mainly northerly tonight at around 10 kt. Winds will become north-northwesterly at around 10 to 15 kt late Thursday morning into the afternoon, with some gusts of 20 to 25 kt possible. Outlook... Thursday Night: No Operational Impact. NO SIG WX. Friday: Low Operational Impact. Slight Chance of SHRA...SHSN. Friday Night: No Operational Impact. NO SIG WX. Saturday: Slight Chance of SHRA. Saturday Night: Low Operational Impact. Slight Chance of SHSN. Sunday: No Operational Impact. NO SIG WX. Sunday Night: No Operational Impact. NO SIG WX. Monday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... The Fire Weather season has officially begun across eastern New York and western New England. Despite this, snow cover is in place across much of the region, which will mitigate any potential fire weather hazards for the time being. Additional snowfall is expected today into tonight for southeastern parts of the area which will continue to prevent issues in the near future as well. A coastal storm will brush far southeastern parts of the region with some snow for tonight. Generally fair but chilly conditions will return for Thursday into Friday, although a passing upper level disturbance could bring some snow showers for Friday. && .HYDROLOGY... No hydrologic issues are anticipated through the week. Although northern areas will stay dry today into tonight, areas south and east of the Capital Region will see some snow for tonight, with the heaviest amounts across Dutchess and Litchfield counties. Total liquid equivalent in these areas will be up to one half of an inch, although areas outside Dutchess and Litchfield Counties will generally see less than a quarter of an inch. This snowfall won`t have any immediate impact on area rivers and streams. Behind this storm system, mainly dry weather is then expected for the remainder of the week and into the weekend. There could be a few passing snow showers or flurries for Friday through Sunday, but this will produce little to no measurable precipitation. A slow diurnal snowmelt is expected over the next several days, with temperatures above freezing during the day, and below freezing at night. There will be little impact on the waterways with minimal, if any, rises. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory until 8 AM EDT Thursday for CTZ001-013. NY...Winter Weather Advisory until 8 AM EDT Thursday for NYZ065-066. MA...None. VT...None. && $$ SYNOPSIS...KL/Wasula NEAR TERM...KL/Wasula SHORT TERM...Cebulko LONG TERM...Wasula AVIATION...Thompson FIRE WEATHER...Frugis/KL HYDROLOGY...Frugis/KL
Area Forecast Discussion
National Weather Service Bismarck ND
955 PM CDT Wed Mar 21 2018 .UPDATE... Issued at 940 PM CDT Wed Mar 21 2018 For the late evening update the only significant change was to delay the onset of fog. Currently, there is an area of stratus/fog along the Canadian border from Columbus and Portal eat to Kenmare and then more patchy in nature from westhope to Rugby and Bottineau. Weather Cameras in this area do not show much in the way of reductions in visibility, with the exception of Kenmare. Also a quarter mile visibility at Estevan so there is likely some patchy dense fog along the Canadian border. Elsewhere dense fog has yet to form, but we do see some visibilities dropping down under 10SM. Too many factors pointing to fog to back off, but we did delay the onset most areas and limited fog to just patchy in nature over the southwest. UPDATE Issued at 646 PM CDT Wed Mar 21 2018 For the early evening update we lowered sky cover across the CWA this evening. Fog and stratus that lingered into the afternoon finally dissipated except for a few areas remaining over the north central and into the Turtle Mountains. Otherwise skies were clear. This will likely set the stage for another round of fog/stratus developing later this evening and overnight across northwest and central ND. && .SHORT TERM...(This evening through Thursday) Issued at 146 PM CDT Wed Mar 21 2018 Short term highlights include patchy fog overnight and the oncoming winter storm beginning Thursday night. Synoptically a ridge axis was centered over the northern Rockies with northwesterly flow over the northern Plains. A surface high remains in place under anticyclonic flow aloft. Light winds associated with the high pressure and continuing snowpack sublimation were enough to continue patchy fog in the forecast for tonight. Thursday mid-level winds turn southerly in response to an upstream trough approaching from the west. Warm air advection, focused to the southwest, will bring surface highs into the low to mid 40s across our west/southwest. .LONG TERM...(Thursday night through Wednesday) Issued at 146 PM CDT Wed Mar 21 2018 Overnight Thursday a potent shortwave ejects out of the deep Pacific trough. Strong mid-level southerly winds reaching 50 kts will amplify moisture transport ahead of the wave as NAEFS guidance has been consistent on anomalous precipitable water values reaching the 99th percentile with this system. Strong lift associated with deep frontogenesis under broad synoptic ascent above will create a swath of moderate to at times heavy precipitation across northwest to south-central and southeast ND. Precipitation type will be heavily dependent on the surface temperature and ice presence within the atmospheric profile. A thermal gradient oriented along the band of precipitation will cause rain to be the dominant precipitation in the southwest with a transition to snow towards the Missouri River and eastward. Uncertainty in accumulation totals along and west of the Missouri River through Lake Sakakawea exist with surface temperatures around or above freezing early Friday morning. The greatest snowfall accumulations continue to be favored across north central North Dakota through the James River Valley where thermal profiles will be coolest under the coupling of intense synoptic/mesoscale forcing. As this band of snow passes to our east late Friday the threat for freezing drizzle on the back end arises with ice loss aloft. The 12Z global model suite continues to indicate additional opportunities for accumulating snow Saturday night into early next week under an active southwesterly flow pattern, with uncertainty in intensity and exact location of precipitation. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 940 PM CDT Wed Mar 21 2018 VFR conditions to begin the 00Z TAF period. It appears KDIK will have the best chance of remaining VFR through the night, although some of the mesoscale models indicate KDIK could be near the low stratus/fog late tonight into Thursday morning. Otherwise KISN, KBIS and especially KMOT and KJMS are expected to develop fog/stratus late this evening or overnight. Once fog does develop IFR to LIFR ceilings and visibilities would be expected to linger through mid to late morning on Thursday, before slowly improving to MVFR Thursday afternoon. A light east to southeast flow is expected tonight and Thursday morning, with an increasing southeast flow Thursday afternoon. Looking at latest RAP BUFkit soundings and GFS lamp guidance there are some indications of more stratus than fog. Will continue to look over this for issuance of the 06 UTC TAFS. Latest mesoscale models continue to indicate low ceilings and visibilities expanding from north central and east central ND westward to areas mainly north and east of Lake Sakakawea and the Missouri River. Tough call, but they have backed off a bit on the expansion into the southwest, including KDIK. && .BIS WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from Friday morning through Saturday morning for NDZ002>005-010>013-021>023-025-035>037-047-048-050-051. && $$ UPDATE...TWH SHORT TERM...AE LONG TERM...AE AVIATION...TWH
Area Forecast Discussion
National Weather Service State College PA
1147 PM EDT Wed Mar 21 2018 .SYNOPSIS... Long-duration, early spring snow storm will begin to finally loosen its grip on the region this evening. The rest of the week will feature cooler than average temperatures and occasional flurries. The weekend now looks to be dry as the next weather system passes to the south of PA. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... The snow is pretty much confined to about the SERN 1/3 of my CWA and the HRRR continues to show it melting away over the next several hours. There is good consensus that any measurable precip will be over by midnight with little more than a few lingering flurries into the wee hours. Final storm totals will range from 10 to 20 inches and will make this the biggest snow event for the 2017-18 winter season. A check of snowfall records at Harrisburg indicates a 2-day snowfall over 1 foot would crack the top-10 2-day March snowfalls, with the benchmark of course being the 1993 "superstorm." As temperatures fall overnight, slick spots could form on untreated roads, sidewalks and elevated surfaces as areas of slush and standing water from melted snow refreeze. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/... Models showing a trailing shortwave diving southeast across the region on Thursday. Upper level diffluence ahead of this feature should result in a fair amount of cirrus. Low PWATS and temps aloft not cold enough to generate moisture flux from the Grt Lks, so not anticipating anything more than scattered flurries across the Laurel Highlands. NBM/Superblend indicating max temps Thursday ranging from the low 30s over the highest terrain of the Alleghenies, to the low 40s in the Susq Valley. However, a tight pressure gradient west of coastal low will produce gusty winds, making it feel even chillier. Bukfit soundings support frequent gusts between 20-25kts. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... All models tracking closed upper level low southeast across Pa on Friday, likely supporting scattered, diurnally-driven snow showers and flurries, mainly over the northern and western mountains. After that, focus will shift toward low pressure lifting out of the Miss Valley next weekend. NAEFS/ECENS indicate this system will likely pass too far south to affect central Pa, but will maintain the slight chance for a period of snow. After that, all med range guidance is showing upper level ridging building into the region, supporting a high confidence forecast of fair weather and warming temperatures early next week. A dying cold front could approach the area late Tuesday, potentially spreading showers into the state. Temperatures should remain below seasonal normals through most of the long term forecast, as upper trough remains over the northeast conus. However, moderation is anticipated by Tue/Wed, as upper trough lifts out. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... Improving conditions to drop down from the north and work in from the west as storm pulls away with VFR conditions at most airfields save for the far southeast....KMDT and KLNS where a band of light to moderate snow continues. Increasing northerly flow should bring back ceiling restrictions in the higher elevations of the west and possibly parts of the southern mountains overnight. Outlook... Thu...No sig wx expected. Fri...Cig restrictions poss NW. Sat-Mon...No sig wx expected. && .CLIMATE... RECORD DAILY MAXIMUM SNOWFALL SET AT HARRISBURG PA... A RECORD SNOWFALL OF 8.1 INCH(ES) WAS SET AT HARRISBURG PA TODAY. THIS BREAKS THE OLD RECORD OF 7.5 SET IN 1964. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...La Corte SHORT TERM...Fitzgerald/RXR LONG TERM...RXR AVIATION...Gartner/RXR CLIMATE...
Area Forecast Discussion
National Weather Service Wilmington OH
939 PM EDT Wed Mar 21 2018 .SYNOPSIS... Low pressure is moving east tonight, allowing high pressure and a drier airmass to build into the region Thursday and Friday. Low pressure will bring a mix of rain and snow to the region for Saturday. High pressure and dry air are forecast to return Sunday and Monday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... Surface analysis suggests a surface trough is currently over the ILN CWA, extending from ESE-to-WNW, with a slight veering of winds behind the southward-moving axis. Precipitation has largely ended across the ILN CWA, with surface observations showing that clouds remaining over the area are generally in the mid-levels. The only exception, for the next hour or two, is the chance for some light flurries or freezing drizzle in southern Ohio / northeastern Kentucky, where a few pockets of low-level moisture still exist. RAP projections (mainly at 900mb and below) and a few light radar returns suggest this is the case, and also suggest that it will come to an end soon. A Special Weather Statement is in effect to highlight the potential for refreezing tonight, as any wet roads will become prone to becoming icy as temperatures fall into the 20s. The main change for this evening forecast update was to drop temperatures overnight, especially where the heaviest snow fell earlier -- mainly in the western half of the ILN forecast area. Temperatures were lowered by several degrees, especially as clearing is beginning to work into the region from the west. In fact, current HRRR/RAP runs suggest temperatures may fall even lower than even in this updated forecast -- possibly well into the teens. That is not out of the question given the aforementioned conditions. Previous discussion > Surface analysis shows low pressure to the east and high pressure to the west. ILN area is under a chilly northerly flow between these systems. Moisture and forcing associated with the low are diminishing and snow is ending. Still will see light snow for a few more hours especially in eastern locations, but little to no additional accumulation is expected. Clouds will linger this evening until clearing from the west arrives overnight with the high moving in. Temperatures will fall below guidance to the lower 20s, with these cold readings aided by snow cover. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Surface high pressure developing under a northwest upper flow will extend across the area Thursday and Thursday night. This will provide dry weather conditions and mostly clear skies through the period. Sunshine and modest warm advection will allow high temperatures in the low to mid 40s, still close to 10 degrees below normal. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... In a northwest flow aloft, our region will be between weak systems to our northeast and southwest on Friday. Surface high pressure will remain in place, and with sunshine, temperatures will warm into the 40s. Focus then turns to a low pressure system forecast to pass southeast through the lower Ohio Valley and the Tennessee Valley Friday night into Saturday night. Strong ascent in the form of a moist low level jet will spread precipitation east/northeast into the region Friday night into Saturday. There is an increasing signal for an accumulating snow event, perhaps significant, for locations along and north of the Ohio River. Many factors will play in how much snow will fall such as surface temperatures, thermal profiles, time of day, exact track of the low, and whether some locations along and north of the Ohio never mix with or change over to rain. We currently have a mix developing north of the Ohio with rain/snow changing to rain south of the Ohio. However, strong lift/dynamic cooling, along with a prolonged easterly flow in the low levels, may keep sounding profiles saturated near or below the 0 degree isotherm for points along and north of the Ohio River. Also, the strong vertical motion will likely occur in the favorable dendritic growth zone which will result in aggregate snowflakes. These types of snowflakes can result in heavy snow with rapid accumulation. So, until confidence increases in ptype and duration, have initially went with conservative in amounts, with the caveats mentioned above that could result in a heavier, more significant snow. This has been placed in the HWO. By Saturday night, the low pressure system will be pulling away to the southeast, allowing surface high pressure to build back into the region for Sunday. After lows between 25 and 30, highs will warm back into the 40s on Sunday. High pressure at the surface and aloft will remain over the region on Monday. Temperatures will continue to moderate with highs in the upper 40s to the lower 50s. For the remainder of the extended, an increasing moist, southwesterly flow will develop around the mid level ridge axis passing to the east. This will bring clouds and the potential for showers as we head into Tuesday. A frontal boundary will try to make inroads into the area by mid week, keeping the threat for rain in the forecast. Temperatures will continue to warm with 50s and perhaps 60s possible by next Wednesday. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... With any remaining light snow departing the area early this evening, VFR conditions are expected through the rest of the TAF period. Ceilings have shifted to VFR, mainly with mid-level clouds, which should persist into the overnight hours before clearing out entirely. Clouds tomorrow will generally just be cirrus and some fair weather cumulus -- remaining VFR through the day. Winds will remain out of the northwest through the period, diminishing some this evening, but increasing to around 8-12 knots tomorrow afternoon. OUTLOOK...MVFR/IFR ceilings and visibilities are possible Saturday and Saturday night. MVFR ceilings are possible again on Monday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Coniglio NEAR TERM...Coniglio/Hatzos SHORT TERM...Coniglio LONG TERM...Hickman AVIATION...Hatzos
National Weather Service Jackson KY
858 PM EDT Wed Mar 21 2018 .UPDATE... Issued at 845 PM EDT WED MAR 21 2018 Snow showers generally continue to become lighter and more scattered in nature. Since around 5 PM, we picked up about 0.3" here at WFO JKL so several higher elevation locations near the VA border will likely pick up more over the next few hours. The snow showers should gradually diminish to flurries with loss of daytime heating and as the upper level low gradually pulls further away. The upslope flow will hang on for a couple more hours near the VA border in the higher elevations and with some accumulating snow still possible there over the next couple of hours. With that in mind, we have transitioned over to an SPS for most of the area, though the Winter Weather Advisory has been extended through 11 PM for the VA border counties. Since 8 PM, an NWS employee reported an icy overpass at MM 43 on the Mtn Parkway. As temperatures cool into an through the 20s tonight, more black ice is anticipated. The above mentioned SPS was initially ran through around 8 AM. && .SHORT TERM...(This evening through Thursday night) Issued at 350 PM EDT WED MAR 21 2018 19z sfc analysis shows deep low pressure exiting the area with healthy cyclonic flow continuing through eastern Kentucky. These winds are upslope and as a result are helping to sustaining snow shower activity even as the low`s center is in the process of jumping to the East Coast. Visibilities with these showers remain between 1 and 2 miles - still impacting the area and likely accumulating a bit. Currently brisk northwest winds are running at 10 to 15 mph with gusts to 25 mph. The CAA on those winds, along with overcast conditions and snow showers, have kept temperatures from climbing too far out of the lower 30s across the area today. Meanwhile, dewpoints are similar to temperatures - generally in the upper 20s to lower 30s. Wrap around snow showers associated with the now coastal low are being enhanced by the upslope flow in the far east supporting some light accumulations this afternoon. Accordingly, will keep the WSWs running through 00z for the entire area, though we may be able to clear the southwest before too long. The models are in good agreement aloft through the short term portion of the forecast. They all depict the deep trough that will run up the East Coast tonight. Trailing energy will exit Kentucky in northwest flow by Thursday morning. Height rises will follow as strong ridging starts to work east out of the Rockies and into the Plains. However, before this can influence the weather over Kentucky much, another short wave will ride southeast out of the northern Great Lakes region and brush by the area to the northeast early Friday morning - maintaining the strong northwest flow at mid levels. Given the good model agreement have favored a general blend with a lean toward the higher resolution HRRR and NAM12 for specifics. Sensible weather will feature snow showers gradually winding down this evening from west to east with accumulating snow expected to be done toward 00z when the WSWs will likely be allowed to drop. Following the snow showers dissipating, clouds will break up from west to east late. CAA and radiative cooling tonight should send readings down into the lower and mid 20s by dawn Thursday. Any left over wet patches or slush on the roads tonight will likely refreeze and create localized black ice conditions. Have messaged this in the HWO and will make sure it is highlighted in the evening weather story, as well. Sunshine and high pressure will bring warmer temperatures to the area on Thursday drying us out and taking care of most of the snow on the ground. For Thursday night, the high will shift far enough east to allow some lower clouds to return to the southwest parts of the area in the form of a developing warm front. Otherwise, expect mostly clear skies to also support a decent ridge to valley temp split overnight outside of the Cumberland Valley. Did make minor adjustments to temperatures tonight to go colder in the places that have deeper snow cover and also due to CAA affects on terrain. Likewise, adjusted temperatures Thursday night for relative elevation differences away from the southwest parts of the area. As for PoPs, lingered them a bit longer and higher in magnitude through the evening and into the early overnight hours in the east. .LONG TERM...(Friday through Wednesday) Issued at 305 PM EDT WED MAR 21 2018 The extended period will feature a mix of rain and snow to start things off, as a couple of low pressure systems move across the region over the weekend. The better chance of accumulating snow at this time looks to be for the period Friday night into Saturday morning. The latest model data indicates that the best chances for accumulating snow will occur north of Highway 80. The second chance for any snow will be Saturday night into Sunday morning, although this shot of snow looks like it will be marginal at best with little if any accumulations expected. Once the second weather system departs the area late Sunday, we should see a period of dry weather to begin the new work week. A ridge of high pressure should keep precipitation associated out of most of the area until Tuesday night. The ridge is then forecast to break down just enough to allow an area of low pressure and its surface front to move across the area on Wednesday. This system could potentially bring a good soaking rain to eastern Kentucky. Temperatures around the area should start off below normal, with highs in the 40s and 50s expected Friday through Sunday. We should see a return to normal temperatures on Monday, with highs that day expected to max out in the mid to upper 50s. Next Tuesday and Wednesday could see a return to well above normal temperatures, with highs on both those days possibly topping out in the 60s. Nightly lows should start off near or slightly above normal Friday and Saturday nights, with above normal nightly lows on tap after that. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 835 PM EDT WED MAR 21 2018 Generally MVFR ceilings with MVFR and some areas of IFR vis in snow showers was occurring across the region. Snow showers should continue gradually diminishing to flurries and ending from northwest to southeast over the next 6 hours or so. As drier air moves into the region, improvement to VFR is expected at the TAF sites through around 6Z. MVFR may hang on for a few hours after that in far southeast KY. Once improvements to VFR occur, VFR should persist through the end of the period as high pressure builds into the area. Winds will average out of the west to northwest at generally 10KT or less through 15Z and then become more northwest at near 10KT. && .JKL WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 11 PM EDT this evening for KYZ087- 088-118-120. && $$ UPDATE...JP SHORT TERM...GREIF LONG TERM...AR AVIATION...JP
Area Forecast Discussion
National Weather Service Spokane WA
442 PM PDT Wed Mar 21 2018 .SYNOPSIS... A change in the weather is expected as a deep upper level low digs offshore tonight. This will pool moisture into the region from the south resulting in an increasing chance of precipitation beginning this evening and continuing at times through Thursday. Most of this precipitation will fall as rain however snow will be possible over the higher mountains. A cold front late Thursday will bring gusty winds and deliver significantly cooler conditions from Friday through the weekend with the threat of rain and snow showers each day. && .DISCUSSION... Tonight and Thursday: The warm front will continue to move north across the Inland northwest this afternoon and evening. It will provide some light rain across the region. The last several runs of the HRRR has shown heavier periods of rain moving up the Okanogan Valley, and across the Palouse early this evening. That is a result of the precip that is currently occurring down in Portland and along the WA/OR border. The upper level trough moving out of the Gulf of Alaska will push south through the night and pick up the moisture that is streaming into California. Our heavier stratiform precipitation will move into the Cascades between 10pm and midnight and then spread east through the night across eastern WA and north ID. The models have been consistent for days of the heaviest precipitation occurring overnight into early Thur morning across the eastern Cascades. There is a period in the morning when precipitation intensity will decrease, and then models show heavy precip again in the afternoon as the cold front begins to push over the Cascades. The heaviest precip in the afternoon will be across the eastern Cascades and stretch across the northern tier of WA. Liquid Precipitation Amounts: Precip amounts will vary. The highest accumulations will be in the northern Cascades north of Lake Chelan where they could see an inch to an inch and a half in the mountains. They valleys will see over three quarters of an inch. The Columbia Basin will see the least precip with a few hundredths up to a quarter of an inch possible. Most of the Basin will see about a tenth of an inch. All other locations will see 0.30 to 0.50 in the valleys with 0.50 to 0.75 in the mountains. The Okanogan Highlands higher terrain could see up to an inch. Snow Levels: Snow levels tonight will be above 5k ft. It isn`t until Thursday afternoon that snow levels will start to fall as the cold front pushes over the Cascades. The heaviest precipitation will occur while snow levels are high. By late Thur afternoon snow levels in the Cascades will drop down to about 3k ft. Snow Amounts: In the Cascades above 5k ft will see the heaviest snow amounts. 7 to 14 inches is possible with amounts 20-22 inches possible as you approach the Canadian border. In the 3-5k ft range they could see a dusting up to 3 or 4 inches, locally up to 5 along the Canadian border. No snow is expected down to the valley floors in the Methow, Lake Chelan, Leavenworth areas. North Id Panhandle will also see some snow accumulation in the mountains...about 1-3 inches, which would fall either early Thur morning, or Thur evening. Winds: Winds will increase ahead of the cold front Thursday morning across the Palouse and into the Columbia Basin. In the afternoon the winds will push into the Spokane area. Southeast winds 10 to 15 mph in the morning becoming southwest 15 to 25 with gusts up to 30 mph. As the front goes through after 3pm, there could be local gusts up to 40 mph. Thunder: Both the GFS and NAM are showing some instability in the afternoon across the Columbia Basin (north and east of Moses Lake) and moving north and east through the afternoon ahead of the cold front. Have added a slight chance of thunder to these locations. /Nisbet Thursday night through Sunday...A vigorous cold front will move from west to east Thursday night and drag an upper level low into the region. The upper level low will dominate the weather through the weekend. The result will be cool and unstable conditions which will support isolated to scattered rain and snow showers across the region from Thursday afternoon through Sunday. One thing in our favor is that model guidance is very similar in showing very dry air moving into the region behind the front. This would mean localized brief moderate rain and snow showers, but overall not widespread moderate to heavy precipitation. Snow levels will drop down to near valley floors Friday then rebound slightly Friday and Saturday to 2000-3000 feet. Some of the higher terrain in the mountains could see some decent accumulations through Friday. The passes will see measurable snow with Sherman Pass and Lookout Pass getting 4-8 inches Friday and Saturday. This will likely come in the form of brief heavy snow showers. The northern valleys down towards the Spokane-Coeur D`Alene metro and south to Pullman-Moscow could see localized heavy snow/graupel showers that could result in a quick quarter to half inch of snow. Both of these will have the potential to make driving conditions quite dicey in a short period of time. Temperatures will drop 7-10 degrees on Friday behind the front and another 3-5 degrees Saturday dropping temperatures in the mid to upper 40s, before rebounding a little Sunday. Gusty winds will continue through early Friday with gusts through the Basin, Pa;louse and ridges 30-40 mph. Monday through Wednesday...High pressure will build into the region Sunday night with a flat ridge over the region that will slowly strengthen through the week. This will bring a drying trend with temperatures warming back to normal through the week with spring like conditions. Tobin && .AVIATION... 00Z TAFs: A storm system will move into the region tonight and linger over the region for several days. Several waves of moisture will move from south to north through the night. Timing these waves out past a few hours will be tough, but expect that cigs will lower and rain chances will increase with each successful wave. Precipitaiton will be stratiform and moderate at times. A cold front will move across the Cascades after 18z Thursday, move quickly through the area and be along the ID/MT border by 00-03z. This period...18-00z will be when the area will receive the heaviest rain and also gusty winds to 25 kts. VFR conditions can be expected through 18z, followed by VFR/MVFR conditons 18-00z. Tobin && .PRELIMINARY POINT TEMPS/POPS... Spokane 43 52 31 46 30 41 / 50 90 80 30 50 60 Coeur d`Alene 41 51 30 44 29 39 / 50 90 90 40 50 60 Pullman 45 52 32 45 31 42 / 50 90 80 40 60 60 Lewiston 47 59 36 53 36 48 / 30 70 60 30 40 50 Colville 41 53 31 47 28 45 / 70 100 100 50 50 60 Sandpoint 38 47 31 43 29 39 / 70 90 100 40 50 70 Kellogg 38 49 29 42 28 38 / 60 80 100 50 50 70 Moses Lake 43 56 31 53 29 51 / 50 60 10 20 30 30 Wenatchee 39 49 31 48 29 50 / 90 80 0 40 20 20 Omak 42 51 31 48 28 48 / 90 100 20 60 30 40 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...Flood Watch from 8 PM PDT this evening through Thursday evening for Northern Panhandle. WA...Flood Watch from 8 PM PDT this evening through Thursday evening for East Slopes Northern Cascades-Northeast Mountains- Okanogan Highlands-Okanogan Valley-Wenatchee Area. && $$
Area Forecast Discussion
National Weather Service Charleston WV
1106 PM EDT Wed Mar 21 2018 .SYNOPSIS... Upper low departs and snow gradually ends. High pressure takes control late week, followed by another low pressure system next weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 11 PM Wednesday...Allowed the remainder of winter headlines to expire. As of 555 PM Wednesday... Updated package to cancel winter weather advisory for the lowlands including southeast OH. Radar and sfc obs indicate that the wet snowfall has became light and not sticking on the ground. Winter weather advisory remains in effect for the western slopes and a Winter storm warning remains in effect for the higher elevations. Rest of forecast remains on track. As of 215 PM Wednesday... Temperatures across the lowlands are largely at or just above freezing, so accumulating snow from anything falling after the early morning hours have been difficult to come by in this particular area. In the mountains, however, snow continues to accumulate, and have this continuing well into the evening. HRRR and RAP are showing a gradual dissipation of coverage and intensity going forward as the upper level closed low accelerates up the Atlantic Coast. High pressure moves in later tonight, scouring out the mountain low level moisture, but hold low end POPs until the thermal trough shows signs of degradation. 850mb temperatures will not recover very much during the day on Thursday. Skies clear southwest to northeast. && .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 320 PM Wednesday... The period begins dry and cold under the influence of broad troughing across the eastern CONUS and surface high pressure. The resulting temperatures will be around 10 degrees below normal for mid-late March. Ridging in the central Plains is interrupted by a rather wound-up short wave aloft ejecting out of the Rockies with lee-cyclogenesis occurring on the surface by Friday afternoon. As the low tracks across toward our area, it will intensify as it enters the right entrance region of a Great Lakes jet aloft. Precipitation along the system`s warm front will enter the Tug Fork/Big Sandy basin by Saturday morning. Depending on the timing of onset relative to solar insulation, snow will fall upon precipitation onset with a brief period of sleet and freezing rain before a switch to all-rain with warm air advection Saturday. Models agree that the center of low pressure will pass to the south of us, limiting convective potential and thus heavy rainfall potential with PWAT barely reaching 0.75" in the Tristate area. As the system exits and cold air advection kicks in with trough passage, temperatures will again drop and switch rain back to a wintry mix/snow overnight. Snowfall accumulations look to be up to 2 inches in the lowlands with widespread amounts generally under an inch. The mountains will likely see more as 850 temperatures begin to drop and support accumulation, especially as the system exits Saturday night into early Sunday, on the order of 2-4" and locally up to 6" total. A light coating of ice is also possible upon onset in the coal fields and sheltered valleys with a warm nose aloft. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 350 PM Wednesday... High pressure and ridging returns Sunday night through early Tuesday with southwest flow finally bringing some much-deserved warmer temperatures into the region. Look for Tuesday high temperatures near 60 in the lowlands with deep southerly flow and strong warm air advection. Positively tilted troughing over the central Plains approaches mid-week, placing us at the end of the fire house yet again - looking a another wet pattern to set up with PoPs rising in the Mid-Ohio Valley Tuesday into Wednesday. Did not deviate much from a consensus blend through the long term. && .AVIATION /03Z THURSDAY THROUGH MONDAY/... As of 145 PM Wednesday... A saturated atmosphere continues over the area. IFR ceilings and visibilities will continue at least through 04Z at HTS and BKW, and through 06Z or beyond at CRW, EKN under IFR/LIFR conditions. PKB must be in the back edge of pcpn with very light snow but MVFR conditions as well as CKB. Snowfall will gradually diminish in intensity and coverage by midnight. Upslope snow showers will be possible to last through Thursday morning along the eastern mountains with IFR conditions. Conditions should begin to improve to MVFR and then ultimately VFR by mid morning Thursday. Upper level storm system will make its exit, with the lower level moisture eroding west to east. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z FRIDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of improvement late tonight may vary from forecast. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. DATE THU 03/22/18 UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 EDT 1HRLY 23 00 01 02 03 04 05 06 07 08 09 10 CRW CONSISTENCY L L M M M M M M M M M L HTS CONSISTENCY M M M M M M H H H H H M BKW CONSISTENCY L L L L L L L L L M M L EKN CONSISTENCY L L L M L L L L M M L L PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY M H M M M M M M M M M L AFTER 00Z FRIDAY... IFR in precipitation with the next system on Saturday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...26/MC NEAR TERM...ARJ/26 SHORT TERM...MC LONG TERM...MC AVIATION...ARJ
Area Forecast Discussion
National Weather Service Blacksburg VA
1134 PM EDT Wed Mar 21 2018 .SYNOPSIS... Low pressure will lift northeast to the New England coast Thursday. High pressure briefly returns to the region on Friday followed by another potential winter weather system over the weekend. && .NEAR TERM /THROUGH THURSDAY/... As of 1130 PM EDT Wednesday... Forecast updated to cancel winter storm warning in the mountains, as snow showers are abating and main support from upper levels has exited along with limited trajectory for upslope. Still should see a few snow showers/flurries early overnight especially in the NC mountains, but no more than an inch or less expected. For those areas that were in the winter storm warning, they have now been placed in a wind advisory for stronger winds gusting 35 to 50 mph. Namely, higher ridges and more concerned with any lingering snow on limbs/trees plus wet ground from the snow causing trees to fall. No other major adjustments were made to the forecast, and have a special weather statement out for black ice due to refreeze further east. Previous discussion from early evening... Adjustments made to PoPs to account for a snow squall currently moving through the New River Valley. While currently not producing any accumulating snow, rates are high enough to suggest that minor accumulations are possible, but not likely. Once this squall dissipates, should be on track that only significant PoPs will be in upslope areas. Also, adjusted overnight winds up slightly per short range HRRR and LAMP guidance. Adjusted current temps to obs but little to no low change required to overnight lows. As of 330 PM EDT Wednesday... 995 mb surface low centered well off the Delmarva coast trails an inverted surface trough westward from its center across central VA into the Alleghany Front. Most significant accumulating snow per radar trends and spotter reports has been mostly in southeast West Virginia. We`re steadily losing the influence of the synoptic-scale significant accumulating snowfall, and in some locations has already since ended. Current temperatures in the upper 20s to mid 30s across the Blacksburg forecast area. Wintry weather and wind will continue to be the focal point in terms of sensible weather. Have made several changes to headlines. The first was to remove the winter weather advisory areas and to clear out a large portion of the Winter Storm Warning. The winter storm warning remains in effect for western Greenbrier, Summers, Mercer, Tazewell, Smyth, Grayson into Alleghany, Ashe and Watauga Counties where the potential exists for significant upslope snow accumulations along with blowing snow. I`ve also issued a impact- based Wind Advisory from the New River Valley to the Blue Ridge, northeast into the southern Shenandoah Valley, Alleghany Mountains and eastern Greenbrier Counties. Though expected winds will likely be either marginal Advisory or sub-Advisory, significant amounts of snow have fallen across this area, and with an expectation of winds increasing tonight into Thursday, the potential for downed trees and powerlines in these areas is elevated. The Wind Advisory runs through noon Thursday. As mentioned, we are quickly losing influence of the primary winter storm. As such, significant snow accumulations in many areas may only linger until early evening at the latest and/or have largely ended. I`ve kept the winter storm warnings going for the upslope areas, as snowfall coverage and renewed intensity to light to at times moderate levels should result. Admittedly, portions of the winter storm warning have largely underwhelmed in terms of accumulations to this point, especially in Watauga and Ashe Counties in NC and into the Mountain Empire region. Did think about downgrading to Advisories for these areas, but after collaboration with surrounding offices, decided to opt for consistency and will maintain the warnings. Upslope snow should really occur this evening through about midnight, and snow will tend to taper from south to north thereafter. Still looking at an additional 2 to 4 inches, with as much as 5 inches along higher ridges in the winter storm warning area. Have also included mention of black ice in the HWO as temperatures cool into the 20s tonight. Specific to the winds, northwest winds will begin to increase tonight. Admittedly, northwest wind gusts peaking between midnight and mid-morning Thursday probably will be quite marginal. However, much of the Wind Advisory area has accumulated significant amounts of snow (between 4 and 10 inches, see public information statement). We had already heard of trees being downed in parts of Summers County due to the weight of snow in the Talcott area. That potential will be greater in the Wind Advisory area with snow-weighted trees and power lines. Threat may also exist in the winter storm warning area, but for now have mentioned potential for downed trees and power lines in the winter storm warning text statement. Peak northwest wind gusts should be between 35 and 50 mph. Clearing conditions expected on Thursday as high pressure builds back into the region. Northwest wind gusts will still be rather strong in the morning hours, but 850 mb wind max begins to decrease and pressure rises begin to drop as the coastal low continues to move away. Mostly sunny skies should also allow for some snowmelt to occur. Highs mid/upper 30s to the low 40s west of the Blue Ridge, into the 40s and near 50 across the Piedmont and Southside. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... As of 330 PM EDT Wednesday... High pressure in the Ohio Valley will build east across our region Thursday night. The upper trof along the East Coast will slide east into the Atlantic ocean. Low temperatures Thursday night will range from the upper teens in the mountains with snow pack to the lower 30s in the piedmont. Temperatures will moderate on Friday with the warm advection just in advance of the next upstream system that may bring back high clouds during the day. High temperatures on Friday will vary from around 30 degrees in the northwest mountains in Greenbrier county to the mid 50s in the Piedmont. Clouds will continue to increase and lower from northwest to southeast Friday night. Low pressure and its associated war front will lift north Friday into Friday night. Some spotty light rain or snow could also work in far western sections late. Low temperatures will generally be from the upper teens in the mountains to the lower 30s along the southern Blue ridge. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... As of 330 PM EDT Wednesday... Low pressure tracks from Tennessee Saturday afternoon, across the Tennessee Valley and Carolinas to the western Atlantic by Sunday afternoon. All the energy will transfer to the coastal low by Sunday night which move northeast in the Atlantic ocean on Monday. Some differences in the guidance how far south this low will move, which in turn will impact where the winter weather will be on the northern side of the baroclinic zone. Timing has been fairly consistent, keeping the best probability of precipitation from Saturday afternoon into Sunday morning. The GFS is faster than ECMWF with spreading of the moisture east. The axis of the heaviest QPF is Variable depending on Model choice. Will mention winter storm potential in HWO. While too early to pin point exact details, looks like the heaviest snow potential will occur in the northwest mountains especially western Greenbrier. Surface high pressure wedges down the east slopes of the Appalachians Monday and Tuesday. Will hold on to isolated pops in case precipitation over the Tennessee and Ohio Valley spills east into the mountains. Another cold front approaches from the west Wednesday and drop south through our region Wednesday night into Thursday. Temperatures will remain below normal through the period, especially daytime highs. && .AVIATION /04Z THURSDAY THROUGH MONDAY/... As of 713 PM EDT Wednesday... Snow showers continue through the region and should begin to taper off in the next few hours in all but the typical upslope areas. Conditions have become VFR for areas east of the blue ridge and should remain as such outside of any remaining snow as the Low responsible for them continues to move away from the area. BLF and LWB will continue to see MVFR to IFR ceilings and vis under northwest flow. Expect snow in these upslope areas to begin to diminish during the overnight and early morning hours as high pressure begins to move in from the west. Conditions should improve to VFR for these locations if not before, then soon after sunrise. Gusty winds are expected during the TAF period as the pressure gradient between the approaching high and the strengthening Noreaster becomes stronger. Extended Aviation Discussion... Mainly VFR conditions are expected by Thursday night through Friday night under weak high pressure. Saturday into Sunday, a return to sub-VFR conditions is expected as our next potential winter weather system crosses the area. && .EQUIPMENT... As of 1021 AM EDT Wednesday... The Mount Jefferson NWR remains off the air. The radio unit needed to repair the system is expected to arrive tomorrow (Thursday). The earliest this system will again be operational will be Thursday afternoon. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...Wind Advisory until noon EDT Thursday for VAZ007-009>020- 022>024-035. NC...Wind Advisory until noon EDT Thursday for NCZ001-002-018. WV...Wind Advisory until noon EDT Thursday for WVZ042>044-507-508. && $$ SYNOPSIS...JH/WP NEAR TERM...AL/JR/WP SHORT TERM...KK LONG TERM...KK AVIATION...AL/JR EQUIPMENT...AL/AMS
Area Forecast Discussion
National Weather Service Sacramento CA
348 PM PDT Wed Mar 21 2018 .SYNOPSIS... Wet weather continues into the weekend. Snow will remain above pass levels through the evening, then lower with significant accumulations at the higher elevations into the weekend. && .DISCUSSION... Brief break in widespread precip early this afternoon with a few cloud breaks adding to increased instability. Breezy south winds have developed and will last into early Thursday with a few gusts to 40 mph. Short term mesoscale models including HRRR are indicating scattered thunderstorm development around 4 pm lasting to as late as midnight. A strong shear environment is in place with helicity values 300-400. Instability will be conditional and dependent on cloud breaks, but Bufkit shows values 200-600 j/kg. Dewpoints have soared into the lower 60`s over the srn Sacramento valley with plenty of fuel for destabilization. High shear environment could lead to rotation and a brief funnel cloud or isolated tornado in stronger cells, as outlined in latest SPC thunderstorm discussion. High freezing levels will likely lower the threat of hail except in the tallest/strongest storms. Decided to upgrade winter storm watch to warning, although snow level forecast remains a bit uncertain. NBM/Nam both bring snow levels down to 6800 feet around 11 pm tonight and down to 6000 feet by late Thursday afternoon. In this scenario just a 500 foot change in snow level could drastically change snow amounts along I80 from Soda Springs to Donner pass where current forecast is for 1 to 2 feet of snow through Thursday afternoon, as snow is forecast to just barely make it down to pass level. Thunderstorms with small hail will also be possible Thursday, as a very unstable airmass moves over NorCal. Additional valley rainfall amounts up to 1.50 inches are possible with mountain values 2.00-4.00 inches are possible during the next 24 hours. This will increase the threat for minor small stream and poor drainage area flooding. A brief break in the wet weather looks likely Late Thursday night and Friday morning, before a colder system brings potentially heavier and lower snow Friday night. Exact details of this system remain a bit uncertain, but decided to issue Winter storm watch for mountain areas above 3000 feet of the srn Cascades and Sierra including I80 and Highway 50. At this time the heaviest snow should move over the Sierra after 8 pm with 1 to 2 feet possible through Sunday morning. Timing and amounts with this system could still change, as confidence is just moderate. && .EXTENDED DISCUSSION (Sunday THROUGH Wednesday) Main upper trough shifts east of the state during the day on Sunday bringing the last of the precipitation for a while as upper ridging builds over the eastern Pacific. Precipitation chances will mainly be restricted to east of the central valley. Precipitation amounts will be quite light but snow levels will be abnormally low at around 1500 to 2500 feet. A few lingering showers may still be possible Sunday night but building high pressure will bring an end to any precipitation threat by Monday. Temperatures warm by several degrees on Monday but are still forecast to run slightly below normal. Upper level and surface gradients indicate breezy north winds which will help to start drying things out. Temperatures continue to warm on Tuesday as upper ridge pushes inland with highs expected to warm to several degrees above normal. Even more warming is expected on Wednesday with highs throughout the valley expected to reach the mid 70s in the northern Sacramento valley. Breezy north winds will continue through the period between an upper low over the southwest U.S and building high pressure over the eastern Pacific. && .AVIATION... Mainly MVFR/IFR conditions next 24 hours TAF sites as a Pacific storm system pushes through the region, with isolated thunderstorms through 06z in the Valley. Mainly IFR over mountains. Snow levels dropping from around 8000 feet this afternoon to around 6500 feet after 06z. Wind gusts 20-30 kt through this evening in the Valley, locally stronger in thunderstorms. Southerly winds into Thursday with gusts 20 to 30 knots northern in the Central Valley, 40-50 knots over the higher Sierra. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning from 11 PM this evening to 11 PM PDT Thursday for West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. Winter Storm Watch from Friday morning through late Saturday night for Burney Basin / Eastern Shasta County-Shasta Lake Area / Northern Shasta County-West Slope Northern Sierra Nevada- Western Plumas County/Lassen Park. && $$