Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 162315 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 715 PM EDT Sat Sep 16 2017 .SYNOPSIS... High pressure will remain over the region into early next 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. && .NEAR TERM /THROUGH SUNDAY/...
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As of 715 PM EDT Saturday...Only nuanced changes early this evening compared to yesterday. Aside from slightly higher dewpoints compared to yesterday essentially is a persistence forecast. Still contending with scattered to overcast stratocumulus deck that blankets a large portion of the forecast area at this point. Even a few rogue light showers being detected by KFCX Doppler radar across Charlotte and extreme northeast Halifax Counties in VA but these are more the exception. Clouds/couple showers are driven by shallow instability generally below 700 mb. Did increase sky cover areawide to reflect current conditions and expected trends. However as was the case last evening, these should begin to thin out appreciably by before midnight. Still expect patchy fog beginning to develop shortly after midnight in the favored river valleys given similar synoptic and local- scale conditions to yesterday. Higher moisture/dewpoints compared to yesterday may afford a larger coverage than prior nights as well. May see locally dense fog in scattered patchy spots by early morning in the New River and Greenbrier Valleys but not anticipating coverage great enough to warrant any fog headlines attm. With good radiational cooling overnight, lows in the upper 50s to lower 60s look on track, with values as low as the low 50s in the sheltered deeper valleys in the western Appalachians. Previous near-term discussion issued at 220 PM Saturday follows... Very little change in the weather pattern aloft and at the surface tonight and Sunday. No change in air mass and fog again overnight into Sunday morning until the surface based inversion breaks. Will keep probability of precipitation low due to the lack of any organized lift. Cooler MET guidance looks reasonable for lows tonight based on trends the past few mornings. Highs on Sunday will be a degree or two warmer than on Saturday.
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&& .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/... As of 230 PM EDT Saturday... Hurricane Jose will tour the east coast through the period. Best chance for rain will come from a weak boundary stalling across the mountains Monday afternoon. On Monday, Jose is at an equal latitude with VA/NC with outer rain bands moving over the coast and possibly over the coastal piedmont to include Southside VA. Confidence on rain bands this far inland is low, especially with low level dry air entrainment and subsidence over the region. If Jose`s track is closer to the coast, then the chances for these rain bands will increase in the vicinity of hwy 29. For now, we will keep PoPs low in the 20% range. Some mountain showers are also possible as a weak boundary stalls across the south- central Appalachains Monday afternoon. Again, confidence is low (30%) on rain chances across the mountains with Jose`s subsidence and/or upper level ridge edging eastward from the Ohio and Tennessee Valleys limiting coverage. If any mountain showers develop, they should fade with loss of heating. On Tuesday, Jose continues to track northward toward the New England coast. Subsidence and/or upper level ridging should keep most of the area dry, but can not rule out a stray showers with the increase in humidity and diurnal heating. Like Monday, showers should fade with loss of heating in the evening. Despite dry northerly flow through the period, the combination of warm air advecting around Jose and subsidence, temperatures will warm above normal both Monday and Tuesday afternoon. Highs will range from the mid 70s to lower 80s each afternoon. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 250 PM EDT Saturday... Hurricane Jose is expected to pick up speed and track out into the Atlantic on Wednesday. Following Jose, a weak back door front will move over the region Wednesday afternoon and evening. Some light rain showers will accompany this frontal passage. An upper level trough will then move over the east coast states Thursday and Thursday night. Underneath this trough is a weak surface high that is expected to wedge south into the Carolinas Thursday night and stay through next weekend. Warm air gliding over this wedge and increasing isentropic lift may keep the skies overcast with light rain or drizzle falling through the day Friday. An upper level ridge moves over the wedge by Saturday which will help remove moisture and lift over the area. This upper level ridge will likely play a role in the track of the next tropical system approaching the southeast US. Temperatures will remain warmer than normal through the workweek. Temperatures fall back towards normal over the weekend. Normals for late September range from the mid 70s to lower 80s. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/...
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As of 715 PM EDT Saturday... Current SCT-OVC VFR stratocu ceilings (bases 060-080) will begin to thin with sunset. Overall persistence forecast to yesterday, and current observations and recent shorter-range cig/visby guidance continue to suggest development of patchy fog at Lewisburg and Blacksburg after 06z. Highest confidence of overnight IFR to TEMPO dense fog/VLIFR conditions at those two sites. A little less certain elsewhere, though I did indicated 2SM BR at Danville and Lynchburg given higher dewpoints which may allow for additional/greater development into the Piedmont. Any fog should thin out and erode by 14z Sunday to VFR fair weather cumulus for Sunday. Winds are light and variable/calm for much of the 00z TAF period. Increasing easterly gradient flow may allow for a light northeasterly component to the wind by afternoon at Danville and the NC Piedmont, with speeds less than 6 kts. Extended Aviation Discussion... Monday there will be enough low level convergence for diurnal isolated to scattered showers and thunderstorms. Tuesday and Wednesday may feature some isolated MVFR showers in the mountains. Otherwise expecting good flying conditions through the middle of next week outside of early morning fog, as ridging remains anchored between Jose offshore, and the next upstream cold front that looks to fade upon arrival next week.
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&& .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...AMS NEAR TERM...AL/AMS SHORT TERM...RCS LONG TERM...RCS AVIATION...AL/AMS

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