Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 240052 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 852 PM EDT Sat Sep 23 2017 .SYNOPSIS... High pressure over the eastern United States will continue to bring mainly warm and dry weather to the region through the first part of next week, while Hurricane Maria stays just off the east coast. A cold front is forecast to cross through the area on Thursday. && .NEAR TERM /THROUGH SUNDAY/... As of 845 PM EDT Saturday... Other than for some high clouds mainly over the east and patchy fog out west, should be another mainly clear/quiet overnight under strong high pressure aloft. Latest dewpoints remain much lower than last night given deep easterly mixing from earlier. Thus thinking fog likely later to develop and primarily in the river valleys so only making slight adjusts to going coverage. Expect this combined with the drier air under mainly clear skies to allow temps to drop off a bit below mos with more 50s mountains to lower 60s east. Otherwise few changes. Previous discussion as of 255 PM EDT Saturday... No change in the general synoptic pattern as a large ridge of high pressure dominates the eastern US while tropical systems over the Atlantic remain far enough removed from the region influence our weather this weekend. Combination of diurnal instability, orographic effects, and some weak short wave energy will keep a chance/slight chance for a shower/thunderstorm in the forecast from the southern Blue Ridge into the mountains of NC. Any precipitation will fade quickly by early this evening with dry conditions for the overnight period. Expect another round of patchy fog/stratus development primarily west of the Blue Ridge. Any fog/low clouds will burn off early Sunday, followed by pleasant weather for to close out the weekend. Temperatures will be similar to previous days. Expect lows tonight in the lower 60s east of the Blue Ridge with mid 50s/around 60 to the west and some cooler readings in the valleys. Highs Sunday will be in the mid 80s/near 90 east to low/mid 80s west. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... As of 257 PM EDT Saturday... Dome of high pressure surface and aloft will reside over the mid- Atlantic Sunday night into Monday night keeping the region dry, though some east-northeast flow allows for some cloudiness to move in from time to time. Temperatures staying above normal. Tuesday, Hurricane Maria shift further north allowing a weakness in the ridge and smaller band of high moisture to head west into the piedmont during the afternoon. However, small threat of showers at this point with subsidence in place. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 147 PM EDT Saturday... Just minor changes to the previous forecast this period as we watch Hurricane Maria track northward off the east coast. An upper ridge over the northeast will slow Maria down some, and as it lifts northeast a slight heading to the northwest toward the Outer Banks looks likely before the stronger upstream 5h trough shifts Maria back east and out to the sea into Friday/Saturday. For our weather still looking fairly dry with warmer than normal temperatures Wed-Thu, then some cooling trend Friday-Saturday as front and upper trough shift across. However, the front lacks moisture so shower chances are very low, as we continue a drier than normal trend. Model trends beyond 7 days continues to paint us mainly dry, but temperatures should be a little closer to or below normal. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... As of 700 PM EDT Saturday... Similar to the past few evenings, seeing isolated convection over far southwest sections, basically well south of any of the TAF locations. Expect these showers to push farther to the southwest and finally dissipate with loss of heating so no mention in the terminals at this point. Thus, expect VFR flight conditions through the period with some nocturnal fog/stratus development primarily expected to affect locations west of the Blue Ridge. Guidance remains iffy on the degree of fog/stratus coverage late espcly given much drier air in place this evening per mixing/dry advection from earlier. However latest fog stability values support at least some dense valley fog very late when saturation occurs. Therefore will continue with earlier trends toward climatology and include brief IFR/LIFR at KLWB/KBCB and MVFR at KBLF/KDAN, while leaving out mention elsewhere for now. Any fog/stratus dissipates early Sunday morning with VFR conditions for the remainder of the period given lingering dry air in place. Extended Aviation Discussion... Overall persistence forecast into early next week as strong high pressure aloft builds in from the northwest keeping tropical moisture offshore. This should also maintain good flying conditions along with mostly dry weather, outside of any late night/early morning fog through Wednesday. An overall dry cold front crosses the region later Wednesday night into Thursday as Maria passes off the Outer Banks. These features likely to cause increasing northerly winds Wednesday into Thursday as the combination of the pressure gradient with Maria kicks in Wednesday, followed by cool advection behind the front on Thursday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...MBS NEAR TERM...JH/AMS/MBS SHORT TERM...JH/WP LONG TERM...WP AVIATION...AMS/JH/MBS is the U.S. government's official web portal to all federal, state and local government web resources and services.