Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 200433 AFDRNK Area Forecast Discussion...RESENT National Weather Service Blacksburg VA 1133 PM EST Sun Feb 19 2017 .SYNOPSIS... High pressure will build over the region tonight and control our weather pattern through at least Tuesday. A weak cold front will cross the area Tuesday night and exit the region on Wednesday. A warm front will move north through the region Thursday into Friday. && .NEAR TERM /THROUGH MONDAY/... As of 945 PM EST Sunday... Losing cloud cover over the western slopes of Southeast WV, but as we head through the overnight some of the high-res models start to feed some low lvl moisture back down toward southern WV. Will keep it less cloudy than the nam, but still should see some sct to bkn cloud cover at times early overnight. The forecast is pretty much on track with lows in the mid to upper 30s west to lower to mid 40s east. Previous valid discussion... Winds will be light and variable overnight. Low temperatures will range from the mid 30s to near 40 across the mountains with around 40 to lower 40s across the Piedmont. The highest ridge tops will be a little milder than their surrounding valleys thanks to warmer air working its way into the area aloft above the nocturnal inversion. On Washington`s Birthday, an upper ridge of high pressure will move eastward from the Tennessee Valley to over the western portion of the forecast area. At the surface, the southern axis of a ridge of high pressure will nose south along the lee of the Appalachians by the afternoon. With building heights, and at worse filtered sunshine through advancing thin cirrus clouds, temperatures will trend milder than those realized today, especially in the west where cloud cover will be significantly less. High temperatures will range from the mid 60 to near 70 across the mountains with lower 70s across the Piedmont. A couple locations may reach or be very close to setting record high temperature records tomorrow. Please see the CLIMATE portion of this discussion for details. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/... As of 235 PM EST Sunday... Models continue to advertise long wave upper ridge moving east and offshore with a weak short wave in the northern stream arriving in the eastern United States by Tuesday night. Jet support is not very impressive Tuesday and Tuesday night with much of the upper diffluence remaining over the Ohio Valley and north. Monday evening western valleys along with the foothills and piedmont will decouple early. Then as the surface and 850MB high moves of the coast wind pick up from the west-southwest so expecting temperatures to rise on the western ridges overnight. Axis of deeper moisture crosses the from West Virginia into North Carolina between 00Z/7pm Tuesday night and 12Z/7AM Wednesday morning. Will be slowing down arrival of precipitation based on this timing. Have also trimmed probability of precipitation behind the front on Wednesday. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 235 PM EST Saturday... Per WPC, not much weight put on the GFS, especially Friday through Sunday, as it is faster with most of the synoptic scale features than much of the other guidance. Timing of the cold frontal passage still similar with the front coming through Saturday morning. 00Z ECMWF had colder air behind the front just brushing through the Mid Atlantic region, which was not nearly as cold and as far a push south as previous runs. High temperatures will still drop about 10 degrees but coldest air will start moderating after Sunday morning. A low level jet and cold air advection will result in strong gusty winds behind the front into Sunday morning. && .AVIATION /06Z MONDAY THROUGH FRIDAY/...
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As of 1124 PM EST Sunday... Looking at potential fog and/or low cigs at BLF and at times LWB. As of 0420z, lower cigs were eroding to the northwest of LWB. However, models trying to infringe into BLF/LWB again by 09z some sct/bkn mvfr to ifr cigs. At the same time IFR vsbys had developed over BKW. Profile soundings suggest that fog will be possible at BLF/LWB but with lack of wet ground and greenup, confidence is not that high, but with models insisting on lower vsbys especially in BLF will keep a tempo there for the 10-12z time frame. Further east will be VFR. The low clouds/fog is expected to go away by 12-14z, with VFR expected through the end of this taf period. Low confidence in cigs/vsbys at LWB/BLF and high elsewhere, through 14z Monday, but high thereafter at all sites. Extended Aviation Discussion... VFR into Tuesday morning. Moderate to high confidence of patchy MVFR conditions across the mountains Tuesday afternoon into Wednesday with the passage of a cold front. East of the Blue Ridge, mainly VFR conditions will prevail. Thursday into Thursday night, moderate confidence of patchy light rain returning to the area, with ceiling and visibilities remaining mainly VFR. Some patchy MVFR is possible. Friday, moderate to high confidence of precipitation trending more showery, as low level jet increases in advance of a strong cold front. Expect a mix of MVFR and low end VFR ceilings and mainly VFR visibilities with isolated, brief sub-VFR visibilities under heavier showers. Surface wind gusts of 20 to 30 kts possible across the higher terrain. Showers may linger in the western mountains Saturday morning. Drier weather will prevail for much of the weekend.
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&& .CLIMATE... As of 315 PM EST Sunday... Record High Temperatures and Year of Occurrence Feb 20 Blacksburg, VA..68 in 1984 Bluefield, WV...67 in 1986 Danville, VA....74 in 1971 Lynchburg, VA...76 in 1930 Roanoke, VA.....75 in 1939 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...DS NEAR TERM...DS/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...DS/KK/WP CLIMATE...DS is the U.S. government's official web portal to all federal, state and local government web resources and services.