Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 191936 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 336 PM EDT Mon Sep 19 2016 .SYNOPSIS...
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An upper low will remain just to our south through most of the week, with a trof of low pressure along the coast locking us into a moist northeasterly flow of air. This will keep unsettled conditions across our region, with just a chance for showers mainly east of the Blue Ridge, through the end of the workweek.
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&& .NEAR TERM /THROUGH TUESDAY/...
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As of 330 PM EDT Monday... The upper trof moving in from the west will be closing off just to our south and lingering for a while. This will allow the remnant surface low off the Carolina coast to spin in place and develop moist northeast flow across the Appalachians and central mid Atlantic. There is no change in airmass behind the frontal boundary that moved through today and this will keep some residual diurnally driven instability in place through tomorrow. However, a good discrete forcing mechanism is not apparent and model guidance seems a bit too robust with POPs. Thus, after lingering shower activity tapers off this evening, the best chance for precipitation overnight and through Tuesday will be across Southside VA and eastern sections of the NC/VA piedmont, tapering to slight chance west of the Blue Ridge and generally dry for southeast WV. Expect temperatures to remain mild tonight with upper 60s east of the Ridge and generally lower 60s to the west. Highs tomorrow will be seasonable with readings around 80 east to mid/upper 70s west.
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&& .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
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As of 330 PM EDT Monday... A shortwave trough traveling towards the southern Appalachians will amplify and close off over the Southeast and during the process will absorb the remnants of post tropical cyclone Julia east of the Carolina. A weak frontal zone across the Mid Atlantic coastal plain along with low pressure wave will remain near the coast during the period. The forecast challenge is how far west the richest moisture or heavier rain pushes. The WPC Day 2 and Day 3 excessive indicate that the marginal to slight chances will be located to our south and east. With a northeast flow transporting Atlantic moisture into our region, increased pops and cloud cover for Tuesday night. Low temperatures Tuesday night will range from the mid 50s in the mountains to the mid 60s in the Piedmont. Increased cloud cover and pops for Wednesday into Wednesday night. Shaped cloud cover towards ConsAll with its gradient from northwest to southeast. Allowed for scattered showers across the southern and eastern portions of the forecast area Wednesday into Wednesday night. High temperatures on Wednesday will vary from the lower 70s in the mountains to around 80 degrees in the Piedmont. Low temperatures Wednesday night will generally be from the mid 50s in the west to the mid 60s in the east. Isolated to scattered showers will continue east of the Blue Ridge Thursday into Thursday night. With the richer cloud cover lowered high temperatures on Thursday to the lower 70s in the mountains to near 80 degrees in the Piedmont. A few showers may linger Thursday night in the southeast portion of the forecast area. Low temperatures Thursday night into Friday morning will feature readings from the mid 50s in the west to the mid 60s in the east.
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&& .LONG TERM /FRIDAY THROUGH TUESDAY/...
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As of 330 PM EDT Monday... The weak closed 500mb low opens to become absorbed in the general west to east flow which gradually takes the clouds and rain east and off the Atlantic coast Friday night. Upper ridge strengthens by Saturday morning but remains undercut by low level southeast flow Saturday ahead of a shallow backdoor front that may slide south into the area by Sunday. This supports isolated diurnal pops Saturday before deeper upstream moisture ahead of a stronger Midwest cold front works east along the backdoor boundary resulting in perhaps more widespread showers by early next week. Leaned temperatures towards Superblend with cooler readings especially for Sunday and Monday with moderating High temperatures for Tuesday.
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&& .AVIATION /19Z MONDAY THROUGH SATURDAY/... As of 245 PM EDT Monday... The frontal boundary has largely washed out across the eastern portion of the region, with TAF sites trending toward MVFR/VFR from earlier IFR conditions. However, there is essentially no change in airmass and residual instability behind the front will keep a chance of showers/isolated thunder around into this evening, though will not mention in TAFs some coverage is expected to be so sparse. Will amend as needed is precipitation approaches TAf sites. By early tonight north to northeast winds will become established around the remnant circulation off the Carolina coast. This will bring additional low level moisture into the region and help saturate the boundary layer, resulting in IFR/LIFR cigs for TAF sites, along with some fog at KBCB and KLWB. Conditions will be slow to improve Tuesday morning so expect sub VFR conditions through the latter portion of the valid period. Guidance appears overly enthusiastic with precipitation chances for Tuesday so will continue with dry TAFs through some showers will be around. Winds will become generally northeasterly at all sites and KLYH/KDAN will see winds over 10kts for the latter portions of the valid period. Extended aviation discussion... Tuesday night through Friday, outside of late night/early morning fog/low clouds, expect mainly VFR conditions with the caveat to this being any lingering effects from Julia per GFS/EC, mainly affecting areas east of the Blue Ridge. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...MBS NEAR TERM...MBS SHORT TERM...KK LONG TERM...KK AVIATION...MBS/RAB

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