Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 141033 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 633 AM EDT Wed Mar 14 2018 .SYNOPSIS... Cold upslope flow through Thursday, with upper level disturbances, the strongest crossing early this morning. Modest warming this weekend with a weakening upper low. && .NEAR TERM /THROUGH TONIGHT/...
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As of 630 AM Wednesday... Forecast on track, with enough snow showers to warrant keeping winter storm warnings and weather advisories going. Got a report from Spencer, WV, at 615 AM of two inches since 430 Am, under northwest to southeast oriented band from there to about Summersville. As of 420 AM Wednesday... After a brief overnight lull, snow showers filled in again across central WV and all along the mountains, with embedded narrow heavier bands amongst lighter snow showers and flurries. This was in response to a deep upper level short wave trough over the area. With the vort max tracking close to the southern end of the forecast area, much of the area is on the cyclonic shear side of the jet, with lift coincident with the developing snow showers. Opted to leave the winter weather warnings and advisories in place until the short wave goes by, given roads are most likely to be impacted by the lower early morning temperatures under cover of darkness. However, this may need re-assessed for early cancellation west prior to end of shift. The remainder of the day will bring upslope snow showers in the wake of the exiting system. The advisories and warnings end lastly in the mountains, early this afternoon, as accumulations diminish and become more localized. Farther west, a mid level cap develops this afternoon as heights rise, and the mixing layer deepens. This should limit the chance to stand something up, and the HWO is now clean for the middle Ohio Valley. There will be a lull even in the upslope snow showers tonight, as low level flow backs. Another cold front will approach toward dawn Thursday. A mid deck will cross in warm advection ahead of it. With little moisture available to this system, precipitation is not likely out of the middeck, although we may be able to squeeze out snow showers in and near the mountains by dawn Thursday, as the cold front approaches. Temperatures were raised a bit early this morning per current trends, and near term and MOS guidance, which otherwise were supportive of the ongoing forecast. Tonight will not be quite as cold as early this morning, given warm advection flow that will be strong enough in the low levels to maintain mixing.
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&& .SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/... As of 245 AM Wednesday... Upslope snow ends with the exit of the broad upper low to the east, followed by height and temperature rebounds. Upper level low tracking from the west still exhibiting filling tendencies in operational models with warm air advection occurring on the front end of the system. This will give snow in the low chance period late Friday night as surface temperatures will not likely be subject to the warm air advection yet. Will stay with rain/snow as opposed to ice for this issuance as operational long term models are hitting way too hard at freezing rain. Temperatures recover into the 40s Saturday, making this a rain event as the highest POPs occur. && .LONG TERM /SUNDAY THROUGH TUESDAY/... As of 245 AM Wednesday... Another upper level low moves in for the long term, deepening in the process with the next rain event for the region. Front end warm advection brings lowlands into the 50s, before the heights and low level temperatures fall in the wake of the low as it deepens towards the mid Atlantic coast. This could spur another snow producing period into the middle of next week as the upper low departs. && .AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
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As of 630 AM Wednesday... Upslope snow showers continue through morning, before tapering off this afternoon. While MVFR stratocu will exist much of the time through this morning, visibility will be highly variable, going from VFR to IFR quickly in heavier snow showers and squalls. For the lowlands, snow showers are most likely at CRW early this morning, as an upper level disturbance crosses. This disturbance will make BKW the best candidate for a heavier snow squall early this morning. Any snow squall can bring a brief but quick onset of IFR to VLIFR conditions, along with stronger wind gusts. PKB and CKB will be in sort of a dry slot much of the time, with VFR, save for MVFR morning stratocu. VFR conditions should dominate throughout the area this afternoon and tonight, although mountainous areas will be slower to improve, with snow showers still possible this afternoon. Westerly surface flow will be a bit gusty at times, especially during today, and also in heavier snow showers or snow squalls. Light to moderate northwest flow aloft will become light to moderate west this afternoon, and then moderate west to northwest tonight. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: Low to medium. ALTERNATE SCENARIOS: Timing of snow showers and associated flight category may vary from forecast, with frequent changes possible. Timing of improvement to VFR on today may also vary from forecast. 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 10 11 12 13 14 15 16 17 18 19 20 21 EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY H H H H H H L L H H M M HTS CONSISTENCY M H H M M M M L H H M M BKW CONSISTENCY L M M L L L L L L M M L EKN CONSISTENCY L L M M H M L L L L L L PKB CONSISTENCY H H M H H H H H H H M M CKB CONSISTENCY H H M M H H H H H M M M AFTER 12Z THURSDAY... IFR conditions possible in snow showers Thursday morning in the mountains.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...Winter Weather Advisory until 2 PM EDT this afternoon for WVZ521-525. Winter Storm Warning until 2 PM EDT this afternoon for WVZ516- 518-520-522-523-526. Winter Weather Advisory until 11 AM EDT this morning for WVZ015-016-018-024>034-039-040-515-517-519. OH...None. KY...None. VA...Winter Weather Advisory until 11 AM EDT this morning for VAZ003-004. && $$ SYNOPSIS...TRM/26 NEAR TERM...TRM SHORT TERM...26 LONG TERM...26 AVIATION...TRM is the U.S. government's official web portal to all federal, state and local government web resources and services.