Area Forecast Discussion
Issued by NWS Blacksburg, VA

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000 FXUS61 KRNK 260216 AFDRNK Area Forecast Discussion National Weather Service Blacksburg VA 1016 PM EDT Wed Apr 25 2018 .SYNOPSIS... A closed upper level trough should move further away from the Mid Atlantic tonight. Another upper level trough could bring more rain during Thursday night into Friday. High pressure should arrive to provide drier conditions during the weekend. && .NEAR TERM /THROUGH THURSDAY/...
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As of 1015 PM EDT Wednesday... Upslope northwest flow is keeping low clouds and isolated light showers in the mountains. These showers will gradually dissipate after midnight as the upper trough moves further away from the Mid Atlantic region. However, the combination of light winds and residual surface moisture should result in more patchy fog by early Thursday morning. Temperatures should rise more quickly by midday once the fog and low clouds dissipate. However, the next upper level trough will approach from the southwest by the afternoon to reintroduce cloud cover and showers.
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&& .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/... As of 300 PM EDT Wednesday... An upper level closed low will begin to track (GFS) to the northeast along the western side of the south-central Appalachian Mountains Thursday night into Friday. The surface low, closely attached to the upper low is expected to track over the mountains and parallel to the Blue Ridge. This system will move north of the area by Friday afternoon. The current GFS track will have rainfall of one to three quarters of an inch for the area, possibly over an inch along the Blue Ridge. According to the ECM, rainfall amounts could be higher across the piedmont (up to an inch) as the low opens into a trough over the mountains with the surface low tracking east of the Blue Ridge. The ECM also develops a deformation zone north of the area which will lead to lower amounts (quarter of an inch) west of the Blue Ridge. The NAM is in between the GFS/ECM to where most of the rain falls along the Blue Ridge and over the piedmont and is similar to amounts. All models have this system exiting by Friday afternoon. Temperatures are expected to warm into the mid 60s west to the lower 70s east. Following the closed low/trough exit Friday afternoon, a couple of weak boundaries will slide across the region through Saturday. Both of these boundaries will usher in slightly drier air each time, but will not offer much in the way of cooler temperatures. The cooler air will come in following a cold front Saturday night. Some light showers along western slopes may accompany each boundary, with maybe a hundredth or two of rain. Since the cold air will not arrive until Saturday night, Saturday`s high temperatures will be close to normal with 60s west to the low to mid 70s east. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 300 PM EDT Wednesday... High pressure will move over the region starting Sunday. Cooler than normal temperatures are expected Sunday. The combination of dry air and abundant sunshine, temperatures will return to normal levels Monday then moderate above normal Tuesday and Wednesday. Tuesday`s and Wednesday`s temperatures could be around 10F warmer than normal with 70s west and 80s east. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... As of 739 PM EDT Wednesday... Stacked low pressure is pulling off to our east and allowing winds to become northwesterly. This will end any lingering showers east of the Blue Ridge early this evening with TAF sites trending to VFR and possibly some late night fog. A different story west of the Blue Ridge where light upslope flow will allow MVFR/IFR clouds and some showers to persist tonight. However any breaks in the clouds may be self defeating as enhanced cooling would generate fog and low stratus, so will include a tempo to IFR cigs/vsby to cover this possibility. All sites will be VFR by mid morning, but clouds will be increasing late in the period as the next system moves in our direction from the lower Mississippi valley. Winds may be a bit gusty very early in the period but expect winds to slacken notably after dark and generally remain light through the period. Extended Aviation Discussion... Unsettled weather conditions should continue for the remainder of this work week as another area of low pressure heads toward the Mid Atlantic. MVFR/IFR ceilings along with rain showers may take place during Thursday night and Friday. High pressure should build overhead to bring VFR conditions for all sites by Saturday afternoon. Good flying weather will persist through the remainder of this weekend and into Monday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...PW NEAR TERM...AMS/PW SHORT TERM...RCS LONG TERM...RCS AVIATION...MBS/PW is the U.S. government's official web portal to all federal, state and local government web resources and services.