Area Forecast Discussion
Issued by NWS Charleston, WV

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502 FXUS61 KRLX 141116 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 616 AM EST Thu Dec 14 2017 .SYNOPSIS... Clipper system exits first thing this morning, then another passes north of the area Friday night. Weak system brings light rain Sunday and Monday. Another clipper crosses Tuesday. && .NEAR TERM /THROUGH TONIGHT/... As of 330 AM Thursday... Clipper system passing to our north this morning is dragging a cold front through the region. Temperatures have been quite warm overnight, but the cold air behind the front is going to waste no time rushing in. In fact, high temperatures have already been reached for the day and temperatures will continue to drop from here on out, but may level off for a period this afternoon if we can sneak in a little sunshine. With the tight thermal packing, we are seeing winds across the Lowlands gusting generally between 30 to 40 mph, but gusts in the mountains will likely exceed 50 mph early this morning when the tightest thermal packing nudges through around 12Z. Had to hoist up a wind advisory through noon today for our mountain zones. Cut back snowfall totals in the mountains, as moisture is limited and the best forcing is well to our north. However, upslope should still be able to squeeze out an inch or two across the western facing slopes of the mountains. There will be some lingering stratus behind the front, so mostly cloudy conditions will persist through the day with maybe some decreasing clouds late in the afternoon to early evening. Much colder night ahead as the arctic high drifts southeastward and settles overhead. && .SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/... As of 420 AM Thursday... Weak high pressure over the area Friday morning quickly gives way to the next, and the last in the series of, weak clipper systems of late. It will track even farther north than its predecessor, crossing this morning, which was tracking farther north than its predecessors, a sign of the breaking down of the eastern U.S. long wave trough pattern. Heights build and flatten as the long wave trough lifts out. Therefore, northern mountain snow amounts Friday night are limited, and the cold air pulls out quickly on Saturday. A southern stream short wave trough gets left behind over the southwestern states, as the eastern U.S trough lifts out. It then ejects east-northeastward, as another short wave trough digs into the southwestern states. This will bring milder air, along with some light rain, across the area Sunday and Sunday night. Central guidance temperatures looked good, other than slight non diurnal warming early Sunday morning. && .LONG TERM /MONDAY THROUGH WEDNESDAY/... As of 420 AM Thursday... Weak high pressure briefly visits Monday morning, but with low level moisture remaining in place, and weak warm advection as the high exits during the day on Monday, it will remain cloudy, with the chance for light rain, or drizzle, into Monday night. A northern stream trough digs into the eastern U.S. Monday and Tuesday, temporarily re-establishing the pattern that breaks down over the weekend. This brings the chance for rain showers on Tuesday, which could transition to snow showers Tuesday night in the mountains, while ending elsewhere. The period ends dry, but, after a modest cool down Wednesday, milder weather takes hold for Thursday, as surface high pressure over the area Wednesday, moves east on Thursday, and an upper ridge crosses. Central guidance temperatures accepted, other than to raise lows in the mountains a bit Monday night, to support an all liquid precipitation type. This reflects above normal temperatures, except close top normal on Wednesday. The latest MEX is higher still, although that may depend upon better mixing. && .AVIATION /11Z THURSDAY THROUGH MONDAY/...
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As of 615 AM Thursday... A strong cold front crossed the region during the early morning hours and much colder air is filtering in behind it. Upslope snow showers in the mountains will continue in the NW flow will continue for the next few hours, but moisture cuts off by late morning and by noon there should only be a few flurries around. Behind the front we can expect MVFR stratus just about everywhere through the day today, with improving conditions later this afternoon. Strong gusty winds with cold air advection will start to weaken later this morning. Gusts higher than 40 knots will still be likely in the mountains until about noon today. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing when snow showers in the mountains end may differ than currently forecast. Low stratus may persists longer at some sites this afternoon. 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. DATE THU 12/14/17 UTC 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21 EST 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16 CRW CONSISTENCY L M M H H M H M M M M L HTS CONSISTENCY H M M M M M H H H H M M BKW CONSISTENCY M L L H H M M M H M L L EKN CONSISTENCY L L L L L H H H M H L L PKB CONSISTENCY M H H H H H H H H H L L CKB CONSISTENCY L H H H H M H L H H L L AFTER 12Z FRIDAY... Another round of snow is expected across the northern portion of the area on Friday and Friday night, with IFR conditions possible in heavier snow showers.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...Wind Advisory until noon EST today for WVZ516-518-520-522>524- 526. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/MPK NEAR TERM...MPK SHORT TERM...TRM LONG TERM...TRM AVIATION...MPK is the U.S. government's official web portal to all federal, state and local government web resources and services.