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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRNK 131925 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 225 PM EST Sat Jan 13 2018 .SYNOPSIS...
-- Changed Discussion --
High pressure will build in from the northwest tonight through Sunday and remain north of the region into Monday. A second surge of Arctic air comes in behind a cold front that passes through the area Monday night and Tuesday.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH SUNDAY/...
-- Changed Discussion --
As of 225 PM EST Saturday... Wind chill advisory has been posted for western Greenbrier county until 10 am Sunday where the combination of wind and temperatures will create very cold wind chills. The NAM, GFS and HiresW-arw-East were slower to diminish moisture and taper off snow showers. A lingering fetch of low level moisture from Lakes Huron and Erie may keep light snow going into tonight. As a result decided to increase pops in the west and extend the chance for snow showers and snow flurries in the west longer into this evening. Any accumulating snow will be less than an inch and will remain confined over the far west with the limited upslope. High pressure to our northwest will build eastward tonight into Sunday. The upper trough will pivot across from the west overnight with another shortwave travel east. This may result in additional upslope clouds in the west. Low temperatures tonight will range from the single digits in the mountains to the lower 20s in the Piedmont. High pressure moves into Pennsylvania on Sunday, providing mostly sunny and dry conditions. High temperatures Sunday will vary from the upper teens in northwest Greenbrier county in West Virginia to the mid 30s in the piedmont.
-- End Changed Discussion --
&& .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
-- Changed Discussion --
As of 200 PM EST Saturday... A ridge of surface high pressure will still be centered across the eastern sections of the region heading into Sunday night. As we progress through Monday evening, the center of this high will be displaced eastward in response to the approach of a cold front from the west. Precipitation-free conditions are forecast during this time period, with temperatures continuing to average about ten to fifteen degrees below normal. By late Monday night, the leading snow showers in association with the cold front are expected to reach a few parts of southeast West Virginia. During the day Tuesday, model guidance varies as to the degree and speed the front and associated precipitation make their way into the region. The bulk of the guidance suggest Tuesday night is a more likely candidate for the actual frontal passage. Isolated to scattered snow showers will be forecast to reach as far east as the crest of the Blue Ridge by Tuesday afternoon, with the best concentration across southeast West Virginia. Snowfall totals, even for most of this higher concentration area, are expected to be less than one inch.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
As of 1100 AM EST Saturday... The Tuesday night and Wednesday time frame of this part of the forecast will be highlighted by a sharply amplified longwave trough that will pass into and across the region. Guidance varies to the degree which moisture will accompany this systems associated surface cold front as it crosses the area. However, was is consistent is that some degree of moisture will. This should leade to at least isolated to scattered snow showers across the forecast area during this time frame. In the wake of the front, northwest flow across western sections of the area should allow for a continuation of isolated to scattered snow showers across parts of southeast West Virginia Wednesday night. We will need to keep an eye on the trend of the forecast wind chills. The latest numbers suggest the region may be close to reaching Wind Chill Advisory thresholds. Heading into Thursday and Thursday night, an already tight pressure gradient may trend even tigher, than thus yield even gustier winds across the area. A lot will depend upon how much offshore development there is a of a coastal low on the tail end of the departing upper trough. Guidance still varies on this potential as well. Late Thursday night into Friday, and continuing in Saturday, look for the synoptic pattern to trend zonal across the area with some upper level ridging across the Gulf Coast states. Anticipate a warming trend heading into the weekend, with little if any precipitation. The only very small chance currently offered would be on Saturday just along the eastward side of the crest of Appalachians. Guidance suggests that slightly higher moisture content air may get lifted upslope in a narrow region, especially the area of the North Carolina Foothills. Temperatures may be cold enough at the onset for an hour or two of very light freezing rain before temperatures rise above freezing for the remainder of the day. Temperatures during this portion of the forecast will start about ten to fifteen degrees below normal Tuesday night into Wednesday. From Thursday into the start of next weekend, anticipate a warming trend that will bring readings to values around five degrees above normal by Saturday.
-- End Changed Discussion --
&& .AVIATION /19Z SATURDAY THROUGH THURSDAY/... As of 1252 PM EST Saturday... VFR conditions will continue east of the Blue Ridge mountains this afternoon into Sunday. MVFR to OCNL IFR in snow showers will continue this afternoon into this evening across the mountains in the northwest flow. Snow showers and snow flurries should taper off this afternoon into tonight. VFR conditions will return to the west by Sunday as high pressure builds in. Northwest winds will remain strong this afternoon with gusts perhaps reaching 30-35 kts espcly along the KBLF-KROA corridor with overall 15-25 kts elsewhere including eastern locations. Any residual clouds should fade tonight as northwest winds slowly diminish ahead of high pressure building in from the northwest. Light winds are expected on Sunday across the region. High confidence in ceilings,visibilities and winds during the taf period. Extended Discussion... VFR expected across the region Sunday night and Monday under high pressure. MVFR snow showers are possible Tuesday and Wednesday from a clipper system. This will lead to another surge of Arctic air. Drier weather is anticipated for Thursday and Friday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...Wind Chill Advisory until 10 AM EST Sunday for WVZ508. && $$ SYNOPSIS...KK NEAR TERM...KK SHORT TERM...DS LONG TERM...DS AVIATION...JH/KK

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