Area Forecast Discussion
Issued by NWS Charleston, WV

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232 FXUS61 KRLX 292324 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 724 PM EDT THU SEP 29 2016 .SYNOPSIS... A large upper level low will bring unsettled wet weather through Friday. It pulls away in time to bring dry weather for much of the weekend. High pressure continues the dry weather early next week. && .NEAR TERM /THROUGH FRIDAY/...
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As of 725 PM Thursday... Thunder coverage on the wane overall. Watching training activity over the northeast zones. No major changes to the forecast grids however as chances for convection are still on the high side...with the highest values across the northeast zones. As of 235 PM Thursday... Deep upper low pressure has settled southward and now remains nearly stationary oscillating over Northern Kentucky. Low level moisture is fairly low across the region with dew points in the upper 50s and this should be a limiting factor for instability. However, visible imagery is showing some breaks in the cloud cover across parts of our Eastern forecast area and CAPE values in these areas could approach 1000 J/Kg. With very cold temperatures aloft, lapse rates near 7C/km and with strong 0-6km bulk shear near 60kts shear, there is potential for rotating updrafts that could support marginal to severe hail and even a weak tornado could be possible. SPC continues to keep the region in a marginal risk...with southern/eastern WV zones in a 2 percent for tornadoes. The next threat that we are concerned with this afternoon is for training of convection across Northeast West Virginia counties this afternoon and this evening. Convection is starting to line up across Northern Virginia and should be moving into Pocahontas and Webster Counties in the next 2 hours. Although flash flood guidance is relatively high, if training were to persist over the same area then flash flooding could become an issue. However, confidence is still too low at this time to issue a Flash Flood Watch, so for now I will just mention in the HWO. Weather will remain unsettled tomorrow with the upper level low still in our vicinity. Expect more showers to develop, mostly across the Northern Half of the Forecast Area. However, there will be much more cloud cover so not expecting the diabatic warming we saw today, so storms will not be strong. Showers will end from south to north as we head into Friday evening.
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&& .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... As of 1222 PM Thursday... Large upper level low over the lower Ohio Valley will move to northern Indiana by Saturday afternoon and then to the eastern Great Lakes late. Showers will be most numerous across northeast portions of the area early Friday night. However, coverage should quickly decrease by early Saturday with much of the area getting into the dry slot. There could still be a few showers in the northern mountains as well as portions of northeast Ohio early Saturday night. However, expect Sunday should be dry across the area. Used a blend of guidance for lows and highs. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 1205 PM Thursday... Period will begin with pesky upper low moving away from the region. Upper level ridge will build in as an upper level trof approaches from the west. Models differ on the track of Tropical Storm Matthew. GFS has the system moving along the North Carolina coast while the ECMWF has it well to the south. Current thinking is to follow WPC timing which is close to that of the GFS. End result should be dry weather Sunday night through Tuesday before the flow around Matthew begins to push some moisture westward into the mountains. This increasing moisture could result in some afternoon/evening showers and storms in the northern mountains Wednesday and Thursday. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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As of 725 PM Thursday... Messy aviation forecast this evening with terminals in and out of SHRA/TSRA, but coverage of the thunder will continue to diminish over the next few hours. Going to play the low stratus card tonight...and have terminals down below 1kft after 03Z. Shower activity will likely raise the ceilings for an intermittent time. Slow improvement of the ceilings after 12Z with the shower activity on the increase again. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY... FORECAST CONFIDENCE: Low to Medium. ALTERNATE SCENARIOS: Coverage and timing of showers and storms tonight and resultant MVFR/IFR restrictions may vary from forecast. Amendments likely. EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY OF WFO FORECAST TO AVAILABLE MODEL INFORMATION: H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS. L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL. UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 EDT 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05 CRW CONSISTENCY H M L L L L L M M L L M HTS CONSISTENCY M M H M M M M M L L L M BKW CONSISTENCY L M M M M M L L L L L L EKN CONSISTENCY H M H H H L H H M H H H PKB CONSISTENCY M M L M M L M M H H L L CKB CONSISTENCY H H H H H H H H H H H H AFTER 00Z SATURDAY... Areas of IFR possible in showers and thunderstorms through Saturday, and in dense fog Sunday and Monday mornings.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...MPK NEAR TERM...MPK/26 SHORT TERM...JSH/30 LONG TERM...JSH/30 AVIATION...26 is the U.S. government's official web portal to all federal, state and local government web resources and services.