Mount Gay-Shamrock, WV Weather

What Has Changed

No significant changes have been made to the forecast for the work week, but rain chances return late this weekend.

Key Messages

1) Dry and warm weather is expected through Halloween, with rain chances returning late this weekend.

Discussion

KEY MESSAGE 1...

High pressure remains large-and-in-charge this week as the Omega Block situated across the U.S. continues to collapse. The center of the subtropical ridge, objectively analyzed at 591 dam per the 12Z UA charts, was centered over the Deep South, with its apex eclipsing the CWA. Farther north, a shortwave trough was digging into far eastern Canada; and the synoptic cold front associated with this system will weaken as it moves into the region Tuesday. Westerly winds today will transition towards the northeast post-FROPA, with the front expected to stall near or along the I-64 corridor. By the middle of the week, the Omega Block will have completely collapsed, which will allow an attenuating shortwave trough to eject over the OH River Valley and into the eastern Great Lakes region.

As this shortwave trough approaches to the west of the CWA, the backdoor cold front that stalled across the region the previous day will undergo warm-frontogenesis and lift northeastward beneath a thickening cirroform overcast. The net result of this should result in some slight improvements to moisture within the boundary-layer due to the restrictions of full insolation and the presence of the modified return flow. Full sunshine is set to return Thursday, as the previous shortwave trough will have quickly become absorbed into a large-scale, cyclonic gyre-like pattern over the northern latitudes of North America. High temperatures will then warm into the middle-upper 70s by the end of the work week as geopotential height tendencies remain slightly positive from the subtropical ridging to the south of the region.

Broadly cyclonic flow is forecast to encompass the CWA this weekend, with slightly cooler, but still mild, temperatures and a thickening overcast for Halloween. Rain chances are appearing to arrive late Saturday night and into Sunday, but it is too soon to iron out the exact timing of PoPs. By the time Halloween arrives, this will be the longest stretch of dry weather observed for the Charleston area since the Fall of 2017, when there was no precipitation for 23 days in a row, with this stretch being 14 days come Halloween.

Aviation

VFR will continue into early Tuesday morning, with river valley fog returning to KEKN, KPKB, and possibly KCRW for a brief period. Winds will remain light for the next 24 hours and transition towards the northeast late Tuesday morning as a weakening cold front moves into the region and stalls.

FORECAST CONFIDENCE: High.

ALTERNATE SCENARIOS: The coverage and timing of fog tonight may vary from the 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 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 H H H H H H 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 18Z TUESDAY... River valley fog will return to at least KEKN and KPKB each morning this week, but confidence is lower for the other terminals. Rain chances return late this weekend.