Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 220001 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 801 PM EDT Sat Oct 21 2017 .SYNOPSIS... High pressure continues through Sunday. A strong cold front and low pressure system crosses early next week, with much cooler weather midweek. && .NEAR TERM /THROUGH SUNDAY/... As of 200 PM Saturday... Intervals of cirrus through Sunday as high pressure shifts to the east. Patchy dense river valley fog overnight, but thinking the combination of cirrus and boundary layer winds will keep much of it confined to the mountain valleys. The smoke plume from the large industrial site fire in Parkersburg should back more toward the north overnight and perhaps into the city of Parkersburg. Should more decoupling occur than forecast, poor ventilation rates and lack of dispersion overnight could result in reductions in visibility. Having said that, this is a low confidence scenario, especially considering the uncertainty regarding how much smoldering will exist overnight. Overnight lows were hedged a few degrees below guidance with highs tomorrow on the warm side of the guidance envelope. && .SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/... As of 235 PM Saturday... Models showing an upper level low pulling moisture into the region on Monday. Still some timing differences in the timing of the rain bands with this system, but the overall pattern is in fairly good agreement. Cold front should push through late Monday/Monday evening. Some models showing rainfall amounts from 0.75 to 1.50 inches, while others show 0.75 to 2.50 inches. With the area being dry recently, flash flood guidance is generally in the 2.25 to 3 inch range in 6 hours, so should be able to handle the rainfall. Will keep an eye on this however. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 235 PM Saturday... Cooler air will move into the area behind the cold front Tuesday and Wednesday as an upper level trough moves over the area. This trough will also provide some moisture and lift, allowing for a chance of showers. With colder air aloft, could see some snow flakes in the higher elevations of the northern WV mountains. High pressure will build over the area for Thursday and Friday. Another strong cold front can then be expected over the weekend. && .AVIATION /00Z SUNDAY THROUGH THURSDAY/... 00Z Sunday thru 00Z Monday... As of PM Saturday... Generally, VFR amid passing cirrus tonight. Smoke plume from fire just south of PKB had shifted east of the terminal and lifted late Saturday afternoon as winds had become southwesterly and mixing occurred. The plume will likely shift back northwestward and lower across the area tonight as winds turn very light southeasterly. Should this occur, vsby and/or cig restrictions may be realized given the lowering ventilation rate and developing low level inversion. So, for now, will just touch on light VFR smoke for PKB overnight due to very low confidence on impact of and duration of this plume. Otherwise, boundary layer winds overnight should keep dense fog out of the taf sites, save of course for KEKN 10Z-13Z where LIFR fog is expected under the inversion. VFR conditions on Sunday with passing cirrus and sw winds 5 to 10 kts. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY... FORECAST CONFIDENCE: High except at PKB. ALTERNATE SCENARIOS: Smoke may restrict vsby and/or cigs more than forecast at PKB tonight. 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 SUN 10/22/17 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 CRW CONSISTENCY H H H H H H H H H H H M HTS CONSISTENCY H H H H H H H H H H H M BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H H H H H H H H H M L M PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY H H H H H H H H H H H M AFTER 00Z MONDAY... Heavy rain at times Monday and Monday night could bring IFR conditions. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RPY/JMV/30 NEAR TERM...30 SHORT TERM...RPY LONG TERM...RPY AVIATION...JMV is the U.S. government's official web portal to all federal, state and local government web resources and services.