Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 200024 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 824 PM EDT Thu Apr 19 2018 .SYNOPSIS... Upper level low with rain showers transitioning to upslope snow showers and lingering into early Friday. Dry weekend, next system arrives Monday night. && .NEAR TERM /THROUGH FRIDAY/... As of 530 PM Thursday... Refreshed hourly temps and dewpoints up to 12 hours. Cancelled wind advisory for the higher elevations. Rest of forecast remains representative. As of 130 PM Thursday... Gusty winds and rain/wintry mix/snow showers continue this afternoon under CAA behind a fast-moving cold front and upper trough. A Wind Advisory is currently posted across the mountain zones to cover stronger winds in higher elevations. A wintry mix ("white rain") has been reported in heavier showers across the lowlands, and a transition to snow showers has already taken place across higher elevations at this time. Shower activity across the lowlands is gradually tapering off from NW to SE with the passage of a 500 mb shortwave today, tapering entirely by sundown. NW flow and Lakes Huron/Erie moisture plumes keep upslope snow showers present in the mountains through early Friday morning with hires models indicating a boost of shower activity between roughly 00-06Z in the north/central mountains. Accumulations will be generally relegated to above 2500 ft, up to 1-3" are possible above 3500 ft. The surface pressure gradient relaxes behind the aforementioned 500 mb shortwave this evening, and gradually decreases winds through tonight, which may lead to an early expiration of the Wind Advisory. Winds will be generally out of the NW, turning northerly Friday. Low level moisture hangs around with widespread cloud cover for the rest of today. Then, high pressure builds tonight to clear and dry much of the lowlands. Calming winds and clearing skies indicate good potential for radiational cooling - this, continued CAA, and dew points dropping into the 20`s justify the currently posted Freeze Warning posted for all of our zones currently in the growing season including western WV, SE OH, and NE KY. Mostly clear conditions allow for a warm Friday in spite of CAA with lowlands highs in the upper 50`s, corresponding with minimum RH`s in the upper 20`s percent. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... As of 330 PM Thursday... The region becomes encompassed by surface high pressure this weekend, helping temperatures to rebound closer to seasonable levels for this time of year. Clear skies will trigger efficient radiational cooling overnight Friday, which may pose a need for frost advisories across the lowlands Saturday morning. As of the latest forecast, Sunday morning will feature slightly warmer temperatures that would keep the need for an advisory at bay. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 330 PM Thursday... High pressure migrates northeastward in response to an upper level disturbance making its way into the region from the central Plains. Next shot at seeing more of an active weather pattern returns Monday night into Tuesday as the low meanders over the lower Ohio Valley and becomes ingested by a stronger system moving down from Canada, which will ultimately push the next cold front through the area around midweek. Chose to go with a model blend for the end of the period due to discrepancies with models that far out. && .AVIATION /23Z THURSDAY THROUGH TUESDAY/...
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As of 740 PM Thursday... Sfc weather charts show pressure gradient loosen up, decreasing northerly gusty winds to northerly at 10 knots or less. Expect these winds to continue to subside towards 04Z when most places are expected to decouple overnight and experience light to calm flow under widespread VFR conditions. The exception could be at and nearby BKW that an MVFR ceiling could develop overnight under northerly flow. However, low level moisture might not be present as dewpoints are in the 20s over the central mountains preventing this deck to form. Boundary layer winds subside from 15 knots to 10 knots or less after 06-09Z, allowing radiational cooling and corresponding drop in temperatures. Despite of ideal conditions for dense fog development, temperatures will drop into the 20s to produce frost or freeze instead. Widespread VFR conditions expected Friday as a high pressure builds from the northwest. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SATURDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: IFR dense fog could develop along river valleys. 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 H H H H H H H H H M M HTS CONSISTENCY H H H H H H H H H H M M BKW CONSISTENCY H H H H H H H H H H M M EKN CONSISTENCY M L H L H H H H H H M M PKB CONSISTENCY H H H H H H H H H H M M CKB CONSISTENCY H H H H H H H H H H M M AFTER 00Z SATURDAY... No widespread IFR conditions expected.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...Freeze Warning from 2 AM to 10 AM EDT Friday for WVZ005>011- 013>020-024>031. OH...Freeze Warning from 2 AM to 10 AM EDT Friday for OHZ066-067- 075-076-083>087. KY...Freeze Warning from 2 AM to 10 AM EDT Friday for KYZ101>103- 105. VA...None. && $$ SYNOPSIS...KMC/MC NEAR TERM...ARJ/MC SHORT TERM... LONG TERM... AVIATION...ARJ is the U.S. government's official web portal to all federal, state and local government web resources and services.