Area Forecast Discussion
Issued by NWS Blacksburg, VA

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127 FXUS61 KRNK 292358 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 758 PM EDT Mon Aug 29 2016 .SYNOPSIS... A weak frontal boundary to our north will slide southward tonight into Tuesday. Tropical depression Eight off the Outer Banks of North Carolina will move northwest tonight, then pivot north to northeast Tuesday into Wednesday. A stronger cold front will approach on wednesday and arrive on Thursday. Another tropical system emerging from the Gulf of Mexico on Thursday is expected to remain to our south and move offshore over the weekend. && .NEAR TERM /THROUGH TUESDAY/... As of 300 PM EDT Monday... Surface high pressure located over the Great Lakes and Ohio Valley this afternoon will move east tonight into Tuesday. A weak frontal boundary slides to the mid-Atlantic coast by Tuesday morning and push southeast into Tuesday afternoon. Tropical depression eight east of the Outer Banks will travel northwest until 8 am Tuesday, then be pushed out into the Atlantic ocean by cold front Tuesday afternoon into Wednesday. The combination of solar heating, instability and low level convergence will generate isolated to scattered showers and thunderstorms this afternoon into tonight. The best chance will be across Southeast WV and far Southwest Virginia. There is also a slight chance across the rest of the higher terrain including portions of the New River Valley. Any slow moving thunderstorm could produce locally heavy rains. Any convection that develops will subside this evening into tonight. Some models like the Hiresw-arw try to generate some showers tonight in the northeast, but looked overdone. Light winds and low level moisture will result in areas of low clouds and fog late tonight into Tuesday morning. Low temperatures tonight will range from around 60 degrees in the mountains to the upper 60s in the Piedmont. A weak frontal boundary will drop southward on Tuesday and stall by Wednesday. Several shortwave will rotate east across the region. The presence of the front will help be the focus for isolated to scattered showers and thunderstorms across the region. The Day two convective outlook places our area in general thunderstorms. High temperatures on Tuesday will range from the upper 70s in the northwest mountains to around 90 degrees in the Piedmont. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 345 PM EDT Monday... There will certainly be quite a bit of interest in the tropics this period with tropical lows along the Mid-Atlantic Coast and eastern Gulf of Mexico. Both features are progged to steer clear of our forecast area, but should be monitored never the less for changes (Please refer to WWW.NHC.NOAA.GOV for the latest information). For much of the central Appalachians and points north, the weather will be influenced by a deepening upper level trough which is forecast to amplify over the Great Lakes and New England by Thursday. A series of surface fronts will come through the forecast area, the first entering the area Tuesday night and stalling Wednesday. This front will be weak, but still become the focus for scattered afternoon and evening showers and thunderstorms Wednesday. The second front will be much stronger, this feature associated with the deepening upper level trough, and will signal a more robust airmass change. Models bring this front through the area during the day Thursday. Again, scattered showers and thunderstorms will be present along this front, but once the front passes Thursday night, both dewpoints and temperatures will take a tumble. Temperatures for mid week will remain seasonably warm. Until Thursdays frontal passage, dewpoints will remain elevated with humid conditions persisting. Actual air temperatures will average about five degrees above normal for Wednesday`s Tmax and close to ten degrees above normal for the lows. Thursday will be the transition day with temperatures returning to normal. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 400 PM EDT Monday... Model consensus is for long wave trough in the eastern CONUS to linger Friday and Saturday before upper ridging returns over the Labor Day Weekend. At the surface, a 1030 mb surface high is progged to pass across the Great Lakes and into New England, wedging down the east side of the Appalachians. If the tropical system in the eastern Gulf of Mexico tracks northeast into the western Atlantic as forecast then this will result in a very dry northeast wind Friday into Saturday between the building high from the north and the departing tropical low to our southeast. At some point (Sunday?) we should start to experience return flow on the back side of the high, the building heights resulting in moderating temperatures. With a dry airmass progged for Friday and Saturday, anticipate good radiational cooling at night. This should allow for surface temperatures to slip into the 50s for lows...and 70s to around 80 for highs. Sunday and Monday will feature warming temperatures with lows closer to 60 and highs in the 80s. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...
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As of 755 PM EDT Monday... Isolated showers and thunderstorms from southern West Virginia into central Kentucky will continue to drift southwest and dissipate after sunset. No impact is expected to local airports. Otherwise satellite pictures showed little cloud cover. VFR conditions are expected overnight in most locations. However, high confidence in VLIFR fog at KLWB after midnight. Fog will fill in the river valleys with MVFR at KBCB early Tuesday morning. Morning fog will burn off by 14Z with VFR expected at all sites through 17Z/1PM. Isolated diurnally driven MVFR thunderstorms will develop again Tuesday afternoon. Coverage will be limited in duration and area, thus holding off on mention at taf sites for now. Extended aviation discussion... Another front will move into the region Thursday with a better chance for MVFR/IFR showers/thunderstorms, followed by cooler and drier air for Friday and Saturday. Most of the period looks VFR at this point, outside of the usual late night/early morning fog/low clouds. At this time, it does not appear that any tropical systems will impact the county warning area.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...KK NEAR TERM...KK SHORT TERM...PM LONG TERM...PM AVIATION...AMS/KK is the U.S. government's official web portal to all federal, state and local government web resources and services.