Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 180337 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 1137 PM EDT Sun Sep 17 2017 .SYNOPSIS...
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High pressure will remain over the region this week resulting in mainly dry and mild weather over the next few days. Jose should track north, off the east coast Monday and Tuesday, before sliding just east of New England on Wednesday.
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As of 1130 PM EDT Sunday... Isolated showers continue to fire up or linger from the Alleghanys south through the New River Valley and into the foothills of NC. High-res models continue this trend until about 3-4am then diminish it, but think showers fade a little sooner. Expect fog to be dependent on cloud cover overnight, with some clearing expected overnight. At the moment fog will be most likely in the New River to Greenbrier Valleys and patchy for the most part, except locally dense near rivers and where it rained this evening. No other changes to the forecast with lows in the mid to upper 50s west, to lower 60s east. Previous early evening discussion... No major changes needed with this update. Variable cloudiness early this evening with weak/relative surface high in place, cumulus cloudiness tending greatest toward the north and west. May see some decrease in cloudiness with loss of insolation toward mostly clear to partly cloudy skies. However some indication in some of the 18z solutions of a weak vort lobe aloft that may maintain or at least slow cloud burnoff. May even see some isolated nuisance showers until midnight in the southern Shenandoah and into the Roanoke Valleys, a trend reflected in the 21z HRRR/NAM-3km and the 12-km NAM. But these should be pretty harmless. Still looking at potential for patchy mist/fog overnight given radiation inversion with best chance in the Greenbrier and New River Valley. No changes to lows which appear on track. Previous near-term discussion issued at 300 PM follows... High pressure will remain in control of our weather this afternoon into Monday. An upper level shortwave will pass to our north this afternoon into tonight. NAM,RAP,Hiresw-arw-east,HRRR,GFS and ECMWF support the mention of isolated showers this afternoon into this evening across the north. The combinations of low level convergence and orographic lift may generate some isolated shallow convection this afternoon beneath dry air aloft. Kept pops trimmed below 30 percent, with the models generally overdoing pops and qpf recently. Hurricane Jose was at 31N and 71.9W at 15z and lift north in the Atlantic ocean. See latest NHC advisory. Any shallow convection will diminish quickly this evening with the loss of solar heating. Residual late day clouds will spread out into a leftover trapped strato-cu layer this evening into tonight, then clearing expected overnight. Light winds and low level moisture will create patchy fog especially in the western valleys. Low temperatures tonight will range from the mid 50s in the mountains to the lower 60s in the piedmont. The Eastern U.S. ridge will continue Monday with a subtle influence from Hurricane Jose as it moves northward just off the coast. Circulation around Jose may push some low level moisture into the region on northeasterly winds Monday, with enhanced convergence and orographic affects from the Blue Ridge westward yielding Isolated to widely scattered showers. High temperatures Monday will vary from the upper 60s in the west to the lower 80s in the east.
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&& .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM EDT Sunday... Upper pattern amplifies over this time frame with a deep long wave trof developing over the western United States and ridging over the east. Future track of Hurricane Jose is very uncertain after Wednesday, with diverging solutions in the models. Monday night into Tuesday night winds will increase over the Virginia and North Carolina Piedmont, from the northeast then gradually from the northwest, in response to Hurricane Jose. This will result in downsloping in the foothills and Piedmont. Will trend toward warmer guidance for afternoon highs On Tuesday. Think high clouds from showers and thunderstorms upstream in the Plains and Mississippi Valley will only extend to the axis of the upper ridge axis and not get this far east. Will be left with low and mid level moisture trapped under the subsidence inversion. Cloud cover and any chance of precipitation will be especially limited on Tuesday when subsidence may be enhanced as this will be the time when Hurricane Jose is the closest to the region. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 1230 PM EDT Sunday... 500MB heights rise and upper ridge continues to build over the east through Friday. Seeing a small probability of precipitation on Monday along the southern Blue Ridge and foothills where there will be weak easterly upslope winds. No organized synoptic scale for precipitation through Sunday. Temperatures will remain at or just above normal. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... As of 725 PM EDT Sunday... Initial VFR conditions through midnight; some potential for VFR/unrestricted showers near Roanoke and Lewisburg between 02-04z. As skies begin to clear after midnight, should see areas of MVFR to IFR mist at Danville, Lynchburg with IFR to tempo LIFR fog at Lewisburg and Blacksburg. Less certainty on full cloud clearing lends a little more uncertainty in how low visibilities may become. May need to watch for potential for MVFR stratus in the eastern Piedmont, though unclear attm if this will extend as far west as Lynchburg or Danville. Winds generally light and variable - tending light easterly in the Piedmont to Roanoke to light east to northeast in the mountain airports. Any morning fog should erode between 13-14z Monday toward VFR conditions. May see some isolated afternoon showers develop along the eastern side of the Blue Ridge and Appalachians. Left out of the TAFs attm due to low confidence on impact. Winds light east to northeasterly. High confidence on ceilings and winds during the taf period. Medium to high confidence on visibilities during the taf period. Extended Aviation Discussion... Overall persistence forecast to prevail for much of next week with strengthening high pressure remaining in place between Jose offshore and weak cold fronts approaching from the west. This should maintain good flying weather outside of early morning fog/stratus through late next week, with only isolated diurnal showers possible each afternoon. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/WP NEAR TERM...AL/KK/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...AL/KK is the U.S. government's official web portal to all federal, state and local government web resources and services.