423 FXUS61 KRLX 160624 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 224 AM EDT Sun Oct 16 2022 .SYNOPSIS... Showers/thunderstorms spread from south Sunday. Cold front Sunday night ushers in the coldest air of the season so far for early next week. && .NEAR TERM /THROUGH TONIGHT/... As of 220 AM Sunday... High pressure exits early this morning, giving way to a mid level flat wave approaching from the southwest, and an initially dry cold front approaching from the northwest. Moisture increases on low to mid level west to southwest flow today, which still remains a bit strong ahead of the flat wave. Now nearer the event, central guidance PoPs have tightened the probability of rain gradient across central portions of the area, with rain showers moving into southeast portions of the forecast area early this afternoon, and then shifting off to the east overnight tonight, as the wave exits. However, showers may develop over the northern mountains overnight tonight, as the cold front crosses, and upslope west to northwest flow develops in its wake. Southeast portions of the area will also be in an overlap of the southwestern extent of bulk shear and the northeastern extent of surface based instability. The strong flow atop the deep mixing layer backing and slackening off beneath may be enough for strong thunderstorm wind gusts, prompting SPC to upgrade to a marginal risk for severe thunderstorm wind gusts across southeastern portions of the area, about as far north and west as a Williamson to Beckley line. With the clouds and rain across southeast portions of the area today, central guidance has flattened the northwest to southeast temperature gradient seen across the area Saturday as a cold front crossed, but still a bit above normal overall. The cold front starts to re-establish the gradient tonight, with lows straddling normals across the gradient. && .SHORT TERM /MONDAY THROUGH MONDAY NIGHT/... As of 216 PM Saturday... Models suggest front will linger to our southeast before pushing away by Monday. Weak high pressure will then build in Monday night bringing precipitation chances to an end. Temperatures should be well below normal for much of the period. In fact, much of the region should see readings at or below freezing Monday night. This could bring an end to the growing season and frost/freeze program. && .LONG TERM /TUESDAY THROUGH SATURDAY/... As of 102 PM Saturday... At the beginning of the period, an upper low will be located over southeastern Ontario with a trough extending southwest across Ohio into central Kentucky. The trough will slowly move southeast across the central Appalachians and middle Ohio Valley Tuesday night. Precipitation should begin to develop across northern portions of the region late Tuesday morning. Precipitation chances should then diminish early Wednesday. The airmass will initially be quite dry which should limit the southern extent of the precipitation during this event. The moisture across the north will diminish on Wednesday as the trough and resultant forcing move away. The airmass will be cold enough for some of the precipitation to begin as snow across far northern West Virginia and the higher elevations before the precipitation changes to rain by late Tuesday morning across the northern lowlands. The precipitation will change back to snow Tuesday night before ending on Wednesday. Any snow accumulations should be light and limited to the northern mountains. High pressure should then begin to build into the area on Wednesday before a weak cold front pushes east Thursday night into Friday. Once again, moisture will be limited and currently think the front will only bring some clouds to the area. High pressure will then take control for Saturday. Outside of the possibility of some snow during this period, overnight lows will be quite cold with temperatures generally in the 30s. Current thinking is that most areas will see a killing frost or freeze Tuesday night or Wednesday night. && .AVIATION /06Z SUNDAY THROUGH THURSDAY/... As of 220 AM Sunday... Increasing high and mid cloud out ahead of a flat wave approaching from the southwest should by and large preclude river valley fog, with the exception on the tygart Valley, where fog forming overnight may briefly become dense right before dawn. AMD NOT SKED continues at EKN with the visibility outage there. The flat wave will bring rain showers across southern portions of the area from late this morning through this evening, bringing MVFR conditions at least as far north and west as BKW late this afternoon through tonight, with a lingering stratocu deck and mist even as the rain ends. Light south to southwest/variable surface flow early this morning will become light southwest today, except possibly a bit gusty up at PKB this afternoon. Light to moderate west to southwest flow aloft this period may strengthen a bit from the southwest across southern WV this afternoon, coincident with steep low level lapse rates associated with daytime heating. This could lead to thunderstorms there that could then bring down strong wind gusts this afternoon, even into this evening. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Fog may not develop at EKN overnight if mid/high cloud arrive or form earlier than anticipated. A thunderstorm may impact BKW later this afternoon into this evening, with IFR or worse conditions, and possibly strong wind gusts. 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 10/16/22 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H H H H H H H H H HTS CONSISTENCY H H H H H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY H H M L L L L M H H H H PKB CONSISTENCY H H H H H H H H H H H H CKB CONSISTENCY H H H H H H H H H H H H AFTER 06Z MONDAY... IFR possible in snow showers in the higher mountainous terrain Tuesday night into Wednesday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JSH/TRM/JP NEAR TERM...TRM SHORT TERM...JSH LONG TERM...JSH AVIATION...TRM