Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 200244 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 944 PM EST Sun Feb 19 2017 .SYNOPSIS... Unseasonably warm through the work week with another weak system late Tuesday into Wednesday. A more organized system drifts this way for Friday. && .NEAR TERM /THROUGH MONDAY/... As of 930 PM Sunday... Clearing has worked southeastward into central WV as weak low level troughing brings in some drier air from OH, while clear skies continue over the southern sections of WV and sw VA. Clouds expected to get hung up, or redevelop along and east of the I79 corridor later tonight. So have adjusted clouds overnight to basically keep them or redevelop east of the I79 corridor. In any event, looks like patchy dense fog, especially in river valleys, will develop between midnight and 3 AM, with clear areas developing faster. As of 705 PM Sunday... Tricky forecast overnight as to what happens to clouds, and in turn, what happens with fog, as weak high pressure and near calm winds develop. Looks like clouds will erode somewhat from the northwest and south, but leaving an east to west band across the central sections where low level inversion is strongest. However, with wet ground and near calm winds, will go with patchy dense fog most areas overnight, just later where clouds hold on. Any clouds and fog will dissipate during Monday morning as mixing of very dry air aloft occurs, leaving at least a mostly sunny afternoon. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 245 PM Sunday... Anomalously warm pattern continues next week. A weak system looks to cross Tuesday night with scattered showers. Improving conditions on Wednesday. No cold air behind this system, so expect the very warm air to hold. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 250 PM Sunday... The very warm pattern to end the work week. showers and perhaps a few storms may fire along a developing warm front Thursday. Temps may soar well into the 70s on Friday in the warm sector, ahead of a potent cold front set to cross Friday night. I have continued the idea of thunder with the front. A significant cool down is expected over the weekend with high pressure building overhead, though still running above normal in the temperature department. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... As of 930 PM Sunday... Adjusted MVFR ceilings overnight to keep them mostly along and east of the I79 corridor. LIFR fog still for on tap for the major TAF sites between 06Z and 13Z, developing faster under where skies are clear. AS OF 710 PM SUNDAY... Weak high pressure building in overnight with near calm winds. One issue is what happens to extensive MVFR ceilings 1000-2000 feet, especially across central sections of the area where a low level inversion is greatest. Hi res models are trending to erode clouds from the northwest somewhat as a weak 925 mb trough with dry air behind it enters SE OHIO and NW WV, and turns winds more to the northwest, while keeping southern coal fields mostly clear to begin with. However, even where MVFR clouds hold, we expect at least patchy LIFR fog to develop overnight due to wet ground and near calm winds, especially in the river valleys. The big question is timing of the fog which will affect the major TAF sites; the more clouds hold at a TAF site the later the LIFR fog. We expect the time of this fog issue to be between 06Z and 14Z depending on cloud erosion. Thereafter, mixing will improve conditions to VFR mostly clear by 16Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY... FORECAST CONFIDENCE: Low. ALTERNATE SCENARIOS: Clouds may erode more than forecast and LIFR fog become even more of an issue overnight. 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 02/20/17 UTC 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14 EST 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09 CRW CONSISTENCY M M M M L L L L L L L L HTS CONSISTENCY M M M M L M H H H H L L BKW CONSISTENCY M L M L H M M L M L L L EKN CONSISTENCY H H H M L L L L L L L L PKB CONSISTENCY M M M L L H L M M M L L CKB CONSISTENCY H H H H H H M M M L L L AFTER 00Z TUESDAY... WIDESPREAD IFR NOT EXPECTED. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RPY/JMV/30 NEAR TERM...RPY/JMV SHORT TERM...30 LONG TERM...30 AVIATION...JMV is the U.S. government's official web portal to all federal, state and local government web resources and services.