Area Forecast Discussion
Issued by NWS Blacksburg, VA

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 222028 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 328 PM EST Thu Feb 22 2018 .SYNOPSIS... High pressure will remain off the Southeast coast into Friday, promoting above normal temperatures. A weak backdoor cold front will drop south tonight, then return north as a warm front late Friday. A stronger front will move through the region from the Ohio Valley this weekend. && .NEAR TERM /THROUGH FRIDAY/... As of 328 PM EST Thursday... A strong subtropical ridge of high pressure will remain anchored off the Southeast Coast tonight into Friday. Record warm temperatures this afternoon will remind everyone of Summer. A weak disturbance tracking around the northwest side of the upper ridge and an approaching back door front from the northeast may generate some showers across the northwest portion of forecast area mainly the Greenbrier Valley. Backdoor cold front will drop south this evening into tonight. This will introduce a cool wedge to areas east of the Appalachians. Have concerns this afternoon that the southern edge of low clouds have been eroding and lifting as it moves slowly south. The frontal boundary is expected to drop south and push down the Blue Ridge mountains. Then, the front will retreat northward Friday. For weather, initially started with convective showers then transition weather type to rain, drizzle and fog. Utilized a blend of the Conshort and NAM to capture the drop of temperatures with the frontal boundary. Low temperatures will range from the mid 40s deeper into the cool air to the mid 50s along the southern Blue ridge. Friday begins with areas of rain, drizzle and fog in the morning, then becomes scattered showers in the afternoon. Temperatures remain a challenge for Friday with a sharp gradient. How far south the front travels will be a key. High temperatures Friday will vary greatly from the lower to mid 70s outside the wedge especially in the western mountains and southwest mountains to the lower to mid 50s in the northeast deep in the relatively cooler air. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... As of 245 PM EST Thursday... Wedge of cool air should slowly weaken Friday night as a surface warm front lifts back northeast through the region before sliding well to the north on Saturday. May still see some spotty drizzle/fog linger in the northeast where the CAD typically holds longer espcly at night, otherwise mainly cloudy with steadying or rising temps in the 40s/50s overnight. Some small shower chance also far northwest as moisture spills over from the front west of the mountains but iffy at this point. Area slides back into the warm sector Saturday behind the exiting warm front and ahead of the main cold front that will approach from the west by Saturday night. This should set the stage for another breezy and very mild day with highs upper 60s to mid 70s under some sunny breaks. Again models attempt to generate scattered showers but likely overdone given slight height rises and focus of better lift well west of the mountains. Therefore lowered pops back to mainly chance far west/southwest and isolated elsewhere which may be generous. Cold front arrives from the west late Saturday night before slowly crossing the region in weakening fashion on Sunday. Appears a pre- frontal lobe of showers may reach the western sections late Saturday night but moreso Sunday morning with this swath of rainfall sliding east across the rest of the area Sunday. However models remain slower with potential for some splitting of the showers over the west with a jump to the piedmont later in the day where some instability will reside. Cant rule out isolated thunder far southeast so will leave in mention with high pops elsewhere for now, but with QPF of only a quarter to one half inch possible. Should be the last of the really warm days espcly if the boundary is slower so bumped up highs well into the 70s east, and 65-70 west similar to most extended guidance Mos. Front likely slow to exit the southeast Sunday night but degree of leftover deep moisture in question given a more progressive scenario off the GFS and brief drying seen on the latest ECMWF. However latest ensembles suggest that a few shower bands may hang on into the overnight espcly south and east until the actual 850 mb boundary crosses which wont happen until very late. This supports keeping in a 20/30 type pop across the region as the cool advection regime steadily increases overnight pushing lows back into the 40s most spots. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 300 PM EST Thursday... Upper flow will transition to a more zonal trajectory by early next week with weak shortwave ridging giving rise to a brief drier period early on before moisture returns by the end of the period. Could see some lingering showers espcly eastern/southern sections Monday in the wake of the exiting front from the weekend, as some solutions including the 12z ECMWF/CMC bring another weak wave up the front across the Carolinas. Therefore despite a lot of uncertainty will keep low pops mainly Monday morning along/southeast of the Blue Ridge before tapering from west to east in the afternoon. Otherwise models show high pressure building in by late Monday while remaining overhead Monday night before sliding to the coast on Tuesday. This should bring somewhat cooler and drier weather into Tuesday night with highs in the 50s/low 60s, which remains a good 10 degrees or so above normal. Fast west/southwest flow aloft looks to bring pieces of upper energy out of the southwest states by Wednesday with a couple waves ahead of a parent mid level system that will eject out into the upper Midwest by Thursday. This should result in an axis of deeper moisture lifting back north through the TN valley by early Wednesday and into our region Wednesday afternoon/night as a warm front edges north. Moisture remains in place well ahead of the trailing cold front that will approach Thursday with at least added showers around. Thus running with decent chance to low likely pops for mid week at this point. Highs again mostly 50s/60s with cooler values mountains Wednesday, and warmer readings possible Thursday east well ahead of the cold front. && .AVIATION /21Z THURSDAY THROUGH TUESDAY/... As of 1240 PM EST Thursday... Scattered to broken MVFR Clouds this afternoon will become MVFR CIGs by this evening. A backdoor cold front in northern Virginia will slow drop south this evening into tonight. In its wake, a northeasterly wind will develop with CIGS/VSBYs expected to drop into the IFR Category tonight with areas of drizzle and fog. Conditions will likely be IFR to start the day Friday and likely remain IFR to MVFR throughout the day. Winds in advance of the backdoor cool front will be S-SW 5-15 mph with gusts to around 25 mph will become northeast behind the front at 5 to 10 mph tonight. Medium confidence in ceilings, visibilities and winds through the TAF valid period. Extended Aviation Discussion... IFR and MVFR will continue into Friday afternoon. The backdoor cold front will stall along the Virginia and North Carolina line and retreat northward as a warm front toward Friday evening. VFR conditions should return for most locations during Friday night and Saturday aside from any typical low clouds along the Blue Ridge on Saturday morning. By Saturday afternoon, shower coverage should increase as a cold front arrives from the west that could bring MVFR/IFR conditions toward Sunday. Better flying weather should return later on Monday and Tuesday. && .CLIMATE... As of 400 AM EST Thursday... Several record high maximum temperatures were set Wednesday. These include 77 degrees at Roanoke, 79 degrees at Danville, 76 degrees at Lynchburg, 73 degrees at Blacksburg, and 74 degrees at Bluefield. Bluefield also set its warmest ever high minimum temperature for February! Records today. Thursday 2/22/2018 Site MaxT/Year HiMin/Year BLF 67/1992 52/1980 DAN 73/1976 51/1981 LYH 73/1930 54/1913 ROA 76/1980 51/1955 RNK 65/1980 44/2017 Friday 02/23/2018 Site MaxT Year HiMin Year KBLF 74 1975 51 1975 KDAN 73 2017 50 1981 KLYH 74 1943 52 1925 KROA 76 1943 54 1925 KRNK 69 1980 46 1990 Below are the all-time warmest minimum temperatures recorded during the month of February, for our five climate sites with long-established periods of record: Warmest HiMin - February: Site HiMin Date BLF 58 Feb 21 2018 - Broke old record of 57 from Feb 5 2008 DAN 60 Feb 18 2008 LYH 59 Feb 20 1939 ROA 57 Feb 12 1932 RNK 52 Feb 16 1990 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK/PM NEAR TERM...KK SHORT TERM...JH LONG TERM...JH AVIATION...KK/PM CLIMATE...PM/KK

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.