Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 281126 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 726 AM EDT Tue Mar 28 2017 .SYNOPSIS... Expect a cold front to move across the area today exiting the piedmont by late afternoon. High pressure works in from the north into Thursday. Friday, another storm system moves in from the southwest with showers and storms. && .NEAR TERM /THROUGH TONIGHT/...
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As of 710 AM EDT Tuesday... Made adjustments to morning forecast based on radar trends, and shifting higher pops more over the piedmont of VA into the Alleghanys with less in the NC foothills. Deeper moisture evidenced on IR and WV satellite has shifted to the piedmont. Upper low/trough over WV works eastward through early afternoon. Where it is during peak heating to determine best coverage. At the moment should be along and east of the Blue Ridge, but even that should be mainly scattered. Previous discussion from early morning... Area of thunderstorms over the NC foothills/piedmont shifting northeast toward southside VA picked up somewhat by high-res models but as usual, the high-res models are too slow by an hour or 2. Still should see higher pops in the piedmont this morning with this batch, with another concentrated area ahead of the front over WV into the Alleghanys. Most support for convection in the east this morning, subsides west, then as we head toward early afternoon, with the front, another band of convection forms from Amherst to South Boston, per RAP, with isolated/scattered showers lingering post frontal in the west. SPC showing marginal risk in the piedmonts today, mainly for this morning into early afternoon. Stabilization per rainfall/clouds will inhibit a good chance of strong to severe storms, but a little bit of sunshine per some of the models this afternoon could enhance the updraft enough to produce a strong/severe cell or two. Appears will see this threat mainly east of a line from Lynchburg to Danbury NC. Expect decreasing trend in pops by dusk with lingering upslope rain showers over WV til midnight. High today will be dependent on sky cover/areal coverage of showers, but leaned a little cooler than MOS. Still expect highs from the mid to upper 60s west, to mid 70s east. Tonight, should be cooler than this morning, but still about 10-15 degrees above normal, with lows in the mid to upper 40s mountains, to lower to mid 50s elsewhere.
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&& .SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/... As of 350 AM EDT Tuesday... High pressure will move out of the upper midwest and wedge down the east side of the Appalachians for the latter portion of the workweek. By Friday, an upper level trof will drive an area of low pressure into the region to do battle with the wedge. Abundant moisture coupled with good dynamic forcing and isentropic lift will make for an increasing chance of precipitation Thursday night and Friday looks to be quite wet. There are indications in the latest guidance that the wedge will hold firm until the cold front passes and this will be a substantial limiting factor in severe weather potential. However, if the wedge retreats and allows warmer unstable air to move in from the south and west there will be strong dynamics in play to support severe weather. It is still a bit too far out to resolve the many details of this nuanced forecast and possible severe threat so later model runs will be watched closely. Will be above normal on Wednesday, but once the wedge becomes established readings on Thursday will be quite cool with most locations in the 50s. Temperatures on Friday will be largely dependent on the ability of the wedge to remain entrenched and look to remain below normal. && .LONG TERM /SATURDAY THROUGH MONDAY/... As of 350 AM EDT Tuesday... An upper level ridge will build over the region behind the departing low pressure system. This will allow high pressure to build at the surface and once again wedge down east of the Appalachians this weekend. Overall precipitation chances will be low with some lingering upslope showers west of the Blue Ridge early in the period, followed by a few sprinkles with the building wedge. Temperatures will continue to be well above normal into the first part of next week. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/...
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As of 713 AM EDT Tuesday... Dealing with mainly VFR cigs this morning, though where showers area, IFR cigs/vsbys likely, but more in a tempo or less time frame. Also some lower cigs across the higher ridges this morning, but not at the taf sites. Front at 11z was located from PIT-HTS-TYS, and should be east of the LYH/DAN area by 22z. Overall think thunder threat will be low, but could still see some out toward LYH/DAN in the early afternoon as upper trough axis moves overhead. Otherwise VFR with clearing this evening. Some MVFR bkn cigs seem likely at times mainly BLF this evening into overnight with wsw upslope helping this. Extended Aviation Discussion... High pressure builds in from the north Wednesday into Thursday with next storm system moving in the Mississippi Valley. A threat for sub-VFR cigs appears likely as the high wedges southwest Wed night into Thursday for most sites. The highest probability of rain will be on Friday along with sub-VFR cigs/vsbys with the showers. Post-frontal northwest flow sub-VFR into Saturday with gusty winds possible.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK/WP NEAR TERM...WP SHORT TERM...MBS LONG TERM...MBS/RCS AVIATION...AMS/WP is the U.S. government's official web portal to all federal, state and local government web resources and services.