652 FXUS61 KRLX 061513 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 1113 AM EDT Wed Apr 6 2022 .SYNOPSIS... Showers and isolated thunderstorms this afternoon and evening, are followed by a strong cold front and rain tonight. A large upper level trough crosses Friday through Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 1115 AM Wednesday... No changes were needed as the current forecast remains on track. As of 715 AM Wednesday... Forecast on track notwithstanding a potpourri of fog and stratus around early this morning. Most morning commuters are likely to encounter some visibility restriction. The surface low has scooted to the middle Atlantic seaboard. As of 400 AM Wednesday... Fog and stratus in the wake of low pressure early this morning will break up later this morning, allowing for some sunshine that will help fuel storms later via daytime heating, depending upon how long the fog and especially stratus persist in the light flow this morning. The light low level flow will eventually give way to strengthening southerly flow this afternoon, ahead of a strong cold front approaching from the west. This cold front is associated with a large, stacked low pressure system over the upper midwest, and crosses the area tonight. A mid level ripple associated with the convection that developed over northern Arkansas overnight crosses the middle Ohio Valley this afternoon. This can close the window of sunshine there is the fog and stratus persist through mid morning, with its clouds and residual elevated convection. A low level warm advection regime today will limit surface based instability to wedge into southern portions of the forecast area, as the cold front occludes a warm front farther north. A high shear/modest CAPE environment will support strong thunderstorms ahead of the occluding cold front, but the best chance for damaging wind will be south of the occlusion. Strong, veering low level flow will lead to storm relative helicity over 500 m2s-2 and over 50s kts 1-3 km bulk shear, for which SPC depicts a 2 percent tornado threat along the Tug Fork, near the warm front and developing triple point low. Much if not all of the convection farther north and east will be elevated, and SPC depicts a marginal risk in the transition area between the greater slight risk threat to the southwest, and the lesser threat to the north and east where the convection is most elevated. The thunderstorm and then shower threat will end from west to east tonight as the front crosses, with stratus and some mist forming in the deadening low level flow in its wake overnight. Central guidance reflects highest temperatures south and east outside elevation effects today, and the modest cooling and drying behind the front tonight. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 245 AM Wednesday... No significant changes to the short term period. Heavier precipitation will be tapering off across the area Thursday morning as the frontal boundary pushes east, but showery weather will take hold for the remainder of the short term period, as an upper trough, and series of shortwaves affect the area. There even could be a rumble of thunder on Friday with the upper low overhead. Much cooler weather taking hold for Friday, with highs only expected to reach the lower 50s. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 250 AM Wednesday... Upper low/trough will continue to linger across the area in the long term period, with showery conditions. Additional shortwave will move through the region on Saturday, ushering in a shot of cooler air, and resulting in light accumulating snowfall across the mountains. Even a few lowland locations could see flakes mix in at times. Low/trough will move off to the east late Saturday night into Sunday, with a few lingering upslope showers continuing across the higher terrain. Drier, and warmer weather takes hold for next week with high pressure building in. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... As of 715 AM Wednesday... A potpourri of stratus and fog makes for a low certainty forecast this morning, will bring ceilings and visibility down to IFR, with VLIFR possible toward dawn. Visibility restrictions should improve to VFR 14Z-16Z, while the ceilings improve to MVFR 14Z-16Z, and VFR 16Z-18Z, generally. A cold front will bring showers to the area later this afternoon and tonight, along with thunderstorms south, which could be strong, The timing has been moved up /sooner/ to the 21Z-00Z time frame late this afternoon/evening. Otherwise, the showers and storms are likely to bring MVFR conditions. The front will cross the middle Ohio Valley 00Z-03Z and the central Appalchians 03Z-06Z, this timing has also been moved up. Light west to southwest surface flow early this morning will become light and variable later this morning, and then strengthen a bit from the south to southeast ahead of the front this afternoon, and then shift to the west behind the cold front tonight Winds ahead of and right behind the front may be a bit gusty. Light to moderate west to northwest flow aloft early this morning will become light west to southwest later this morning, and then moderate to strong south to southwest ahead of the front this afternoon into tonight, before switching to light west to northwest behind the front tonight. The strong south flow up across eastern WV tonight makes low level wind shear a possibility for CKB and EKN, depending inversely on whether surface gusts occur. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z THURSDAY... FORECAST CONFIDENCE: Low. ALTERNATE SCENARIOS: Timing and intensity of restrictions in ceilings and visibilities could vary early this morning, as may timing of improvement later this 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. UTC 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02 EDT 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22 CRW CONSISTENCY H H H H H H H H H H M M HTS CONSISTENCY H M H H H H M H M M H H BKW CONSISTENCY H M H H H H H H H H H H EKN CONSISTENCY M M M H H H H H H H M H PKB CONSISTENCY H H H H H H M H H H M H CKB CONSISTENCY H H H H H H H H H H H H AFTER 12Z THURSDAY... IFR in fog and stratus into Thursday morning. Brief IFR in rain and showers across the higher terrain Friday, becoming possible across the low terrain by Saturday morning. IFR continuing in the mountains in snow showers through Sunday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/SL NEAR TERM...KH/TRM SHORT TERM...SL LONG TERM...SL AVIATION...TRM