Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 251852 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 252 PM EDT SUN SEP 25 2016 .SYNOPSIS... High pressure shifts east tonight. A cold front will cross Monday with showers and thunderstorms. More autumn like temperatures arrive for the remainder of the week. && .NEAR TERM /THROUGH MONDAY/... As of 230 PM Sunday... Models are in good agreement with a cold front moving rapidly eastward across the area Monday. The front will reach the Ohio River by early afternoon and in the mountains by evening. Even with the speed of the system, models have a combination of decent dynamics and pooling of moisture to near 2 inches along the front. Thus, a band of showers and thunderstorms is expected to accompany the front. However, QPF amounts will only be on the order of a quarter to half an inch, thanks to the speed of the system. SPC continues to outline a marginal risk of severe weather, and will continue this in the Hazardous weather product. Models also have a prefrontal band of convection forming Monday afternoon along and east of the I79 corridor. Not too certain about an organized area of convection there, so will go with scattered convection there in the moist and unstable air; ahead of the frontal band of convection. Convection will then ramp down fairly quickly in the west behind the front by end of period...with even some sunshine by later afternoon. Milder tonight with increased moisture and southerly winds picking up late, especially in the west. Highs Monday will still reach into the 80s ahead of the front. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 430 AM Sunday... Strong cold front will move through the region on Monday...exiting to the east Monday night. Showers and thunderstorms...will develop across the area on Monday...particularly across WV and southwest VA based on frontal timing. There is the possibility that a few storms could be strong to severe on deep layer west- southwesterly winds increase to 40+kts. SPC has placed much of WV and SW VA counties in a marginal risk for Monday. Have added wording to the HWO to mention the strong-dmg wind threat for Monday. Frontal boundary will be to the east of the CWA Monday night...with gradual clearing taking place behind the front. Remainder of the short term period looks to be upper low/trough deepens across the eastern U.S. There could be periods of cloud or showers...particularly across the north at times before the low finally moves off the coast by late week...but much of the time should remain dry. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 340 PM Friday... While the operational models are at least consistent with a stout upper low bringing a cold front through in the short term portion of the forecast, the evolution of the upper low beyond that in the extended is where forecast spread comes into play. The ECMWF continues to bring the upper low south into the central Appalachians, with it oscillating around that general area through the end of the week. The GFS brings a similar track to an extent...but eventually has it become an open wave and exiting our area by Friday. This makes the grids challenging because of a GFS specific trough axis dropping in and creating more defined areas of potential precipitation while the ECMWF will be more involved with less specific forcing details. Crossing fingers for increased model run consistency in the coming days to sharpen up this part of the forecast. Will keep the cooler trend going through the period regardless with low end POPs. && .AVIATION /19Z SUNDAY THROUGH FRIDAY/... 18z Sunday thru 18Z Monday... Weak high pressure this afternoon and tonight will shift east by Monday morning, followed a cold front moving east across the area Monday. A VFR mostly clear afternoon on tap for the lowlands and west facing slopes of the WV and southwest VA mountains. On east facing slopes of the mountains, look for SCT-BKN stratocu 2500-3500 feet AGL this afternoon which will affect BKW. Light and variable winds this afternoon, except light easterly winds on east facing slopes. Tonight will feature a similar night to last night. Near calm winds in most of the lowlands, with just an increase in mid to high clouds late tonight, will result in generally MVFR to locally IFR river valley fog after 06z, affecting mainly CRW EKN. Winds will stir just enough to keep fog out of PKB and HTS. Light southeasterly winds in mountains will bring MVFR/IFR ceilings back to mainly east facing slopes of the mountains including BKW after 02z. After 12z, look for rapid dissipation of fog and mountain stratus as southerly winds increase ahead of the cold front. With moisture and instability increasing, there may be a pop up shower or storm anywhere during the afternoon ahead of the front. There will be a band of showers and thunderstorms, with generally MVFR to locally IFR conditions, with the cold front as it moves across the area. Look for the front to reach the Ohio river by 18Z and the mountains by 00Z. Southerly winds 5 to 10 KTS ahead of the front, turning westerly 8 to 12 kts behind the front. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY... FORECAST CONFIDENCE: Medium ALTERNATE SCENARIOS: Timing and height of fog and stratus reformation tonight may vary. Timing of band of convection with the front Monday may be a bit faster than 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 18 19 20 21 22 23 00 01 02 03 04 05 EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01 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 M H H H H H H M M M M L EKN CONSISTENCY H H H H H H H H H M M L 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 18Z MONDAY... Low stratus possible over the mountains Monday night. Morning valley fog possible Tuesday through Thursday mornings. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JMV NEAR TERM...JMV SHORT TERM...SL LONG TERM...26 AVIATION...JMV is the U.S. government's official web portal to all federal, state and local government web resources and services.