Area Forecast Discussion
Issued by NWS Blacksburg, VA

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317 FXUS61 KRNK 141337 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 937 AM EDT Sat Oct 14 2017 .SYNOPSIS... High pressure was centered over the Carolinas this morning and will remain over the region through Sunday morning. Low pressure developing in the central Rockies tonight will track northeast and push a strong cold front through the area Sunday night. High pressure follows the front for the rest of the week. && .NEAR TERM /THROUGH TONIGHT/...
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As of 937 AM EDT Saturday... Made some minor adjustments in temperatures and dew points with surface obs, trends and leaned towards GLAMP for late morning into this afternoon. Low clouds and fog slowly lifting this morning. The wedge should erode this afternoon. Because cloud cover will make a big difference in high temperatures this afternoon, additional modifications in temperatures will be made later this morning. As of 300 AM EDT Saturday... Strong wedge is in place that evening soundings indicated was close to 3000 feet AGL deep. The western edge of the clouds curved from western Greenbrier County to Bland County to the North Carolina/Tennessee border. Models indicated light northwest 850MB winds for part of the day and show the wedge eroding between 16Z/noon and 20Z/4PM. The longer it takes to clear out the cloud cover the cooler the highs will be for the day. Could easily see a 10 degree difference in high temperatures between locations depending on cloud cover. Until then, the highest elevations will be in the clouds and valleys west of the Blue Ridge will have fog. Moisture becomes shallow overnight. NAMNest and some ensemble guidance suggest a layer of status will develop in the foothills and piedmont late tonight with fog in the valley to the west. Have increased cloud cover and fog after midnight to trend in this direction. May lower minimum temperatures in the western valleys with little cloud cover expected. Otherwise MET/MAV guidance look reasonable for lows tonight.
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&& .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... As of 340 AM EDT Saturday... Low pressure moving into the Great Lakes region will push a cold front into the area late on Sunday, with the front making slow progress across the region Sunday night. Guidance is trending a bit wetter with the front so will nudge POPs up a bit to good chance/low likely for the majority of the region. Also expect breezy conditions as circulation around the low amplifies the low level wind field late Sunday into Sunday night. The front will be in no great hurry to exit Monday so some lingering showers east of the Blue Ridge especially out toward Southside Monday morning. A large area of high pressure will build in behind the front with noticeably cooler and drier air surging in on a northerly breeze later on Monday. The high will then take up residence over the region and bring pleasant fall weather through Tuesday. Conditions both Monday and Tuesday night look conducive to some patchy frost mainly west of the Blue Ridge. Sunday will feature one last day of temperatures well above normal with readings in the low/mid 80s east of the Blue Ridge and in the mid 70s/near 80 to the west. Behind the front temperatures will dip a bit below normal with highs in the middle 60s east to upper 50s/lower 60s west. Lows Monday night will be in the lower 40s east to mid 30s west, with some cooler readings in the valleys. Lows Tuesday night will be in the upper 30s/lower 40s east to lower/middle 30s west. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... As of 350 PM EDT Friday... High pressure at the surface and aloft will remain and build over the area through the entire period. Only the GFS hints at a possible upper-low pressure off the coast late in the period. Even if that occurs, the moisture will remain well east of our area. Otherwise, a very dry air mass with strong subsidence will prevail through the period. 850mb temperatures will slowly recover back into the +15C range by the end of the period allowing temperatures, below normal at the beginning, to be near to slightly above normal by the end of the period. Have kept pop values at 0% through the entire period. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... As of 730 AM EDT Saturday... Satellite pictures showing sharp western edge of clouds and wedge from KLWB to KMKJ to K0A9. Ceilings were IFR to MVFR and gradually lowering. Locations in the west that did not have cloud cover had IFR to LIFR fog, including at KBLF. Conditions will slowly improve through the late morning. By the early afternoon, all but only a few locations will be VFR conditions as the lee side wedge erodes. Confidence is medium that the wedge will erode between 16Z/noon and 20Z/4PM at the local TAF sites. Models again develop a shallow stratus layer overnight. MVFR to IFR ceilings are expected in the piedmont of Virginia and North Carolina. Valleys west of the Blue Ridge that are not under cloud cover will again have fog. Extended Aviation Discussion... VFR conditions expected Sunday after the stratus and fog dissipate. A cold front will arrive Sunday night to bring a chance of showers with accompanying MVFR/IFR ceilings and visibilities into Monday. The cold front should head offshore on Monday night, which will allow conditions to improve to VFR by Tuesday. High pressure will return to provide good flying weather through Wednesday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...AMS NEAR TERM...AMS/KK SHORT TERM...MBS LONG TERM...RAB AVIATION...AMS/DS is the U.S. government's official web portal to all federal, state and local government web resources and services.