Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 280005 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 805 PM EDT Sat Aug 27 2016 .SYNOPSIS... High pressure will be the dominant weather feature into the first part of next week with just a chance for an afternoon shower or thunderstorm west of the Blue Ridge. A weak cold front will then approach from the west and bring an increasing chance for more showers and storms for the middle of next week, mainly west of the Ridge. && .NEAR TERM /THROUGH SUNDAY/... As of 330 PM EDT Saturday... The weak backdoor front being pushed along by the wedge of high pressure building down form the northeast is generating some scattered showers/storms mainly across Southside VA and into NC. DCAPE values are quite high and will allow for some storms to have gusty winds, but overall dynamic support is lacking so the threat for any severe weather is low. Expect the storms to continue migrating into the NC mountains before dissipating this evening. Behind this boundary direr air will work in from the northeast so do not expect to see extensive fog development unless the pool of warm and moist air gets hung up west of the Blue Ridge. Much more pleasant conditions will settle over the region for Sunday with less humidity and temperatures just slightly above normal. Lows tonight will generally be in the upper 60s to around 70 degrees east of the Ridge, with middle 60s to the west. Highs on Sunday will be in the upper 80s./near 90 east to generally mid 80s west. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... As of 400 PM EDT Saturday... Models are in relative agreement with a broad area of high pressure persisting from the Mid-Atlantic westward into the central CONUS early in the week. Wind flow during this period will be from the northeast with models indicating relatively stable air east of the Blue Ridge. A surface frontal boundary is forecast to approach from the northwest Monday night into Tuesday, albeit weak. For Monday, can`t rule out an isolated shower or thunderstorm west of the Blue Ridge, but support for anything greater in terms of coverage appears lacking. Surface front drifting in from the north should permit a bit more coverage Tuesday. Temperatures through early week will remain quite warm with highs in the 80s to near 90. Overnight will generally be in the 60s. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 400 PM EDT Saturday... General model consensus for the second half of the week is for the upper ridge to give way to some weak upper level troughing over the eastern CONUS, progressive flow across the northern tier states gradually whittling away at the eastern ridge. This should allow for another front to come through from the northwest during the period, although model uncertainty is high with respect to timing per unresolved solutions ongoing in the tropics. As such will keep the forecast pretty close to persistence with respect to precip probabilities, but shave a degree or two off the temperature per potential for drier air to infiltrate from the north later in the week, temperature trending closer to normal. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/...
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As of 800 PM EDT Saturday... Weak backdoor front associated with wedge of high pressure building down from the northeast was generating some scattered thunderstorms from southwest Virginia into southern North Carolina. Cluster of thunderstorms crossing west through the mountains at 00Z/8PM will push a gust front through the KBLF airport before 01Z/9PM. The general trend will be for the storms to weaken and dissipate before midnight with no impact to area airport after 10PM. Behind this boundary direr air will work in from the northeast which will limit the potential for fog/stratus development overnight. TAF sites west of the Blue Ridge may be lingering in the moist air long enough to generate some degree of low clouds and fog, but based on predictors in the meso models believe the most likely scenario is for the drier air to move in fast enough to prohibit the need to mention fog or low clouds. KDAN had rain Saturday afternoon and the dew point depression at 00Z/8pm was only 2 degrees so will be watching for fog formation at that airport. It is possible that fog will develop shortly after sunset then dissipate overnight as lower dew points arrive and the surface winds increase from the northeast. This is not a high confidence forecast and the potential for below VFR conditions will be reevaluated with later model runs. With the dry wedge in place for tomorrow, VFR flying conditions are expected at all sites through the end of the TAF period. Extended aviation discussion... A weak west-east oriented front will drift south through the forecast area Sun-Mon. Isolated diurnally driven convection will be possible along the front, mainly north of I-64 Sun, toward the I-64 corridor Mon, then toward the NC/SC border by Tue. Coverage will be limited in duration and area on all days and have minimal impact on the TAF sites. Late night/early morning fog/low clouds are possible, but not a certainty. At this time, it does not appear that any tropical systems will impact the CWA.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...MBS NEAR TERM...MBS SHORT TERM...PM LONG TERM...PM AVIATION...AMS/MBS is the U.S. government's official web portal to all federal, state and local government web resources and services.