Area Forecast Discussion
Issued by NWS Blacksburg, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 200920 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 420 AM EST Sat Jan 20 2018 .SYNOPSIS...
-- Changed Discussion --
High pressure aloft and at the surface will build over the region into early Monday. Temperatures will continue to moderate from the recent Arctic cold as this occurs. A strong system will move from the Midwest into the Ohio Valley through Monday, passing through our region Tuesday. Widespread showers and gusty winds are expected to accompany this weather system, followed by much colder temperatures and mountain snow showers into midweek.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
As of 415 AM EST Saturday... Quiet weather expected today and tonight with a continued warming trend. Primarily a cloud and temperature forecast. Remnant Arctic high that brought our most recent cold temperatures was drifting slowly east off the southeast U.S. coast. Return moisture was tracking from the Gulf through the Midsouth and into the Ohio Valley, including adjacent West Virginia, up the west side of the Alleghanys. Models generally hold most of these clouds to our west, but could see some creeping as far east as JFZ, BLF, and HLX at times. Eastern sections should remain mostly clear again today. 850mb temperatures average around +8C across the region today, warming toward +10C by Monday. Clouds may temper max temperatures in the west a bit, while remnant snow cover from 1-4 inches eastern sections should hold temperatures down a few degrees from what otherwise would be expected. Leaned toward the cooler GFS/ECMWF for temperatures and undercut eastern areas 2-3F degrees today and 1-2F degrees for min temps Monday. Otherwise, look for a nice day with high temperatures in the 40s and 50s and lows tonight around freezing to near 40 with mainly west to southwest winds 5-10 mph.
-- End Changed Discussion --
&& .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
As of 300 AM EST Saturday... The upper pattern will be in transition as a large closed low over the midwest opens up and moves into New England early next week. So aside from a slight chance of showers far west of the Blue Ridge for the first part of Sunday, the Appalachians and central mid Atlantic region will have fair but breezy conditions through the first part of Monday with temperatures well above normal. By Monday afternoon the chance for showers will be increasing in the mountains later in the day as a strong cold front approaches from the west. Guidance continues to advertise the front with a good deal of dynamic support, being driven by low pressure moving through the Great Lakes. The front is expected to be accompanied by widespread rainfall though lapse rates are not impressive and surface based instability is largely absent so chances for thunder look quite low. However, the low level wind field amplifies considerably and there is very healthy shear along the front so embedded convective elements may be able to mix down strong wind gusts without thunderstorms. While the likelihood of this is not great due to the lack of instability, the possibility can not be dismissed due to the energetic nature of the system. The front crosses the region Monday night with precipitation tapering off to lingering upslope showers west of the Blue Ridge on Tuesday. Winds behind the front will become quite gusty through Tuesday night and a wind advisory may be necessary. Also, with colder air moving in behind the front some wet snowflakes are possible at the higher elevations west of the Ridge. The lingering upslope snow showers will persist into Wednesday morning.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY THROUGH FRIDAY/...
-- Changed Discussion --
As of 200 PM EDT Friday... Overall airmass behind the cold front is not that cold as it has a Pacific origin, so not an arctic blast. Temperature start to rebound late in the week as we dry out with surface high building in from the TN Valley midweek, and off the VA coast by Friday.
-- End Changed Discussion --
&& && .AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... As of 1115 PM EST Friday... VFR SKC conditions projected for most of the TAFs through late tonight as high pressure continues to govern the region. Only significant aviation operational weather impact in this period will be from low-level wind shear w/ westerly low-level jet of 35-40 kts as winds decouple. This could lead to areas of turbulence especially along or west of the western mountains/Blue Ridge. Toward daybreak, the ceiling forecast becomes less certain along or west of the Blue Ridge. Current low cloud layer entering eastern TN may reach the far western sections very late tonight. Latest Nam continues to depict some of this cloud cover making it through the very dry air but iffy at this point. Thus will show ceilings lowering to at least a SCT deck by 12z/7am for KBLF/KBCB, then trend closer to BKN/OVC VFR/MVFR (025-040 bases) at KBLF during the morning. Confidence in ceilings lower than VFR is low to medium for these locations, but given recent trends expect there to be at least VFR strato-cu around. Would expect VFR SKC conditions elsewhere. Though west winds should increase to 10-20 kts, with gusts to 25-30 kts tomorrow, there may still be pockets of low-level wind shear at Bluefield and Blacksburg with low- level jet increasing to 40-45 kts. Extended Discussion... Generally VFR for the TAFs through Sunday, with exception being lingering SCT-BKN MVFR stratus Saturday night west of the Blue Ridge. Sub-VFR conditions will start to return to the area Sunday night into and through Tuesday night as a cold front and its associated precipitation moves through the region. Very gusty northwest winds return to the area Tuesday night into Wednesday on the backside of the departing system. Lingering sub-VFR conditions possible across SE WV thanks to strong upslope flow and residual low level moisture. && .EQUIPMENT... As of 325 PM EST Friday... NOAA Weather Radio, WXL60 (Roanoke Transmitter) which broadcasts at 162.475 MHz remains off the air. The phone company reported that the circuit line had been cut and will take until Monday January 22nd to fix it. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...RAB NEAR TERM...RAB SHORT TERM...MBS LONG TERM...MBS/WP AVIATION...DS/JH EQUIPMENT...WP

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.