Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 241733 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 133 PM EDT Sun Jul 24 2016 .SYNOPSIS... Strong high pressure aloft will continue to bring increasing heat and humidity today through Monday. A series of weak surface cold fronts approaching from the northwest should gradually bring an increasing threat for showers and storms by the middle of next week. && .NEAR TERM /THROUGH TONIGHT/...
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As of 130 PM EDT Sunday... Fair weather cumulus clouds beginning to develop over the mountains but none are threatening to produce rain. Delayed the timing of diurnal thunderstorms and lowered chances by 10%. Storms that do manage to form will not last long into the evening. As of 211 AM EDT Sunday... Upper level ridge will continue to shift east today with the core of the highest heights about overhead this afternoon. This should bring the warmest air aloft into the region with 850 mb temps of around +24C later on. After a warm start, expect the hottest temps so far to occur this afternoon with most spots outside of the higher elevations topping 90 degrees, with 95-100 along/east of the Blue Ridge. This may chase record highs in spots, espcly BCB/BLF per climate section below. In addition, heat indices will likely reach 101-104, espcly east of Highway 29, but moreso in parts of Southside Va where could see brief 105 advisory criteria. However since trends have been for dewpoints to mix out more while guidance has been too hot, wont hoist a headline for just a couple counties, mainly Charlotte/Halifax at this point. Otherwise expecting mainly sunny skies with convection quite limited given little support aloft and warm mid level temps. Still appears some weak low level convergence across the western ridges could combine with heating/instability to pop isolated slow moving storms far west by mid/late afternoon. This mainly along/west of the Interstate 77 corridor where moisture may be slightly deeper and the cap weaker. Thus keeping a 20/30 pop espcly west of the Blue Ridge as still expecting the core of the upstream MCS to stay north for the most part. Guidance suggesting any evening storms to fade by midnight if not sooner with the ridge hanging on while more organized convection stays to the north/west. This should again allow for mainly clear skies outside of debris clouds overnight, with patchy fog valleys and muggy lows, mid/upper 60s west to 70-75 east.
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&& .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... As of 330 AM EDT Sunday... We will remain in quasi zonal flow on the warm side of the jet stream through the middle of the week. A shallow trof will drive a surface low through the Great Lakes/southern Canada and help push a weak front into the region on Monday. However with zonal flow there will be little forcing to nudge the front clear of the region, which will allow it to wash out over the area. The old boundary combined with warm and unstable air will enhance our coverage of showers and thunderstorms through the first part of next week. The synoptic environment over our area does not favor organized severe convection, but will have to watch for pulse storms with some clustering. With a typically vague summertime pattern will structure POP girds with the usual diurnal bias for a peak in the later afternoon/evening, then tapering off during the overnight hours. Will wait for convection to declare its intentions before getting more specific with the grids. High temperatures will continue to run a few degrees above normal with a slight cooling trend through midweek. Expect highs to be in the low/mid 90s east of the Blue Ridge with readings generally in the mid/upper 80s to the west. Lows will be 70 to 75 east, 60s west. && .LONG TERM /THURSDAY THROUGH SATURDAY/... As of 315 PM EDT Saturday... Little change in the overall pattern will mean a persistent chance each day of afternoon and evening showers and thunderstorms. Northern stream upper trof will bring some lift into the region Friday. Temperatures will be close to normal through the period. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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As of 128 PM EDT Sunday... LWB observation have returned as of 17Z Sunday. Outside of a very isolated diurnal thunderstorm, overall VFR conditions expected to continue for most of the period with high pressure aloft in place. Will again see some patchy fog in the valleys early Monday morning under thin high clouds. Extended aviation discussion... Strong high pressure aloft looks to remain in place on Monday with continued VFR outside of developing convection Monday afternoon/evening. However coverage of storms on Monday again looks rather isolated until late and mainly confined to mostly the western mountains at this point. Ridge will finally weaken through mid week as an initial cold front sinks toward the area from the northwest. This should bring about an increase in daily convective coverage Tuesday into Thursday with periodic MVFR/IFR possible. Late night and early morning fog will likely occur at the usual valley locations, and those chances increase across the entire region if any rain occurs during the afternoon or evening at any site.
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&& .CLIMATE... Record high temperatures for today (7/24) Roanoke.....100 in 1933 Lynchburg...100 in 2010 Danville....101 in 2010 Blacksburg...92 in 1991 Bluefield....91 in 1987 Record high temperatures for Monday (7/25) Roanoke.....100 in 1934 Lynchburg...102 in 1934 Danville....102 in 2010 Blacksburg...92 in 1987 Bluefield....90 in 1987 && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH/RCS NEAR TERM...JH SHORT TERM...MBS LONG TERM...MBS AVIATION...RCS CLIMATE...JH is the U.S. government's official web portal to all federal, state and local government web resources and services.