Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 280759 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 359 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/... As of 310 AM EDT Tuesday... 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. && .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 /08Z TUESDAY THROUGH SATURDAY/... As of 113 AM EDT Tuesday... Expect a period of showers and isolated thunder in the BLF/LWB areas at the start of the taf period with area of showers moving into ROA/BCB by 08z, then DAN could see some as well by 09z, with LYH toward 11z. Attm will have VCTS in the tafs since instability has weakened. Showers will bring the cigs/vsbys to high end IFR at times especially BLF/LWB, otherwise should be VFR. A few gusts as well possible but too infrequent for tafs. Front is across southern OH into Wrn KY early this morning and should be moving across the mountains in the 12-18z time frame, exiting the piedmont by 21z. Most of the showers and thunderstorms will occur in pre-frontal trough ahead of it but some lingering showers are possible in the mountains this afternoon, namely BLF/LWB. Could see a brief gust to 20-25 kts after fropa. Any precip will be out of the CWA by dusk. Looking at period of MVFR cigs at BLF and possibly LWB after 00z into Wednesday morning. 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. && .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.