Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 050605 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 105 AM EST Mon Dec 5 2016 .SYNOPSIS... A weak system is crossing the area overnight. A low pressure system crosses late Monday night and Tuesday. Briefly milder in its wake mid week. Colder after a cold front passes Thursday. && .NEAR TERM /THROUGH TODAY/... As of 1 AM Monday... Trimmed the western edge of the PoPs overnight but added drizzle as the rain diminishes. Forecast otherwise on track. As of 900 PM Sunday... Increased PoPs as upper level short waves transits area. Radar and obs showing widespread rain over the area. Weak front passes in the early morning hours of Monday. Not expecting a lot of QPF, but what does fall in the mountains may fall as freezing rain as a tongue of warm layer aloft slides into the region, so maintaining winter storm advisory there. Slick roads are the main concern. As of 230 PM Sunday... Warm air advection aloft and weak isentropic lift is bringing light rain to Southwest Virginia this afternoon. The rain has been confined mostly to our south with just mid and upper level clouds currently across the forecast region. Fairly dry air in the low levels has mostly kept precip at bay and seeing just mid level clouds across much of the region for now. Low level southeast flow this afternoon and into the evening will likely produce upslope clouds and an isolated shower in the Eastern Mountains but not expecting widespread PoPs to enter the region until later this evening with approaching short wave. The weak shortwave moves through late tonight into tomorrow morning. Dewpoints are mostly in the mid to upper 20s and as precip moves in this drier air at the surface will likely allow for some evaporational cooling. Although confidence is still fairly low at this time, there is certainly still some potential for a wintry mix, including periods freezing rain overnight, mostly across the parts of Randolph and Pocahontas counties. Not expecting significant impacts, but a trace to a couple of hundredths of ice accumulation could make for slick travel. Have decided to leave current winter weather advisory as is for now. High pressure builds back in for a brief period tomorrow and conditions should improve late morning into the early afternoon. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... As of 315 PM Sunday... No major changes to the short term forecast with decent model run to run consistency. Trickiest part of the forecast will be the cold air trapped in the far northern mountain valleys at the onset of precipitation, as this would likely translate to another marginal freezing rain issue in isolated areas. Will transition to rain eventually, and this will be more of a liquid precipitation event as opposed to the onset freezing rain potential. For the timing, isentropic lift on the 295K surface arrives after 06Z Tuesday over the Tug Fork Valley and will overspread the rest of the CWA fairly quickly. Frontogenetic forcing will also pass through quickly, while the center of low pressure passes and drags a cold front through into Tuesday night. Still looking at around an inch of liquid precipitation for the system. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... As of 325 AM Sunday... Cold front for Thursday is looking a bit weaker in latest model runs with the closed 500mb low not as deep as previous runs. Southward penetration of the 850mb thermal trough will be less as a result of the weaker system overall, but will still get near -16C down into the middle Ohio Valley for the end of the week. Post frontal/cold advection snow possible behind the front. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... As of 100 AM Monday.... The weather had dried out along and west of the Ohio River as of 1 AM, and light rain and drizzle will diminish east of the Ohio River from west to east overnight, as a weak cold front pushes east. Drizzle will linger in the mountains into Monday morning, but any overnight freezing rain or drizzle across higher terrain, above 3000 or 3500 feet, should be gone by daybreak Monday. Low MVFR to IFR stratus deck will persist into Monday, with IFR ceilings most prevalent and persistent in the mountains. MVFR visibilities in and near the mountains will tend to improve through early Monday morning, although higher ridges may be obscured by stratus. Drier air associated with high pressure crossing Monday afternoon will result in clearing and VFR conditions. High clouds will start to lower and thicken from the south Monday night, as the next low pressure system approaches. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing of MVFR VS IFR ceilings may vary overnight and Monday morning. May have the visibilities in TAFs too high into Monday morning. 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 MON 12/05/16 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 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 M M M M L H H L L H M EKN CONSISTENCY H H M L M M L L L M M L PKB CONSISTENCY M 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 06Z TUESDAY... IFR possible in rain on Tuesday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Winter Weather Advisory until 6 AM EST early this morning for WVZ523-524-526. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/JW/MPK/26 NEAR TERM...TRM/JW/MPK 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.