Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 281837 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 237 PM EDT Sun May 28 2017 .SYNOPSIS... Showers and thunderstorms through tonight. Cold front tonight, with drying into Monday. Cold fronts cross Tuesday and Wednesday. Unsettled again next weekend. && .NEAR TERM /THROUGH MONDAY/... As of 230 PM Sunday... Added the flash flood watch to the northern counties, but convection proving slow to fire today with a few weak cells here and there. High res models have been consistent on increasing coverage over the next few hours, and have followed this thinking with the POPs. Flash flood guidance across the northern tier is low since the activity last night. Cold front enters the area ofter 04Z with the next batch of showers and storms, fading as it moves to the east and its surface low racing northeastward. Next upper trough will be quick to follow into the Great Lakes, so not expecting any extended periods of high pressure heading into the short term. && .SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 530 AM Sunday... Upper level low drifts from Lake Superior to near James Bay, Canada, this period, establishing a long wave trough position over the eastern United States. This allows a series of cold fronts to drive progressively drier, cooler and more stable air into the area so that, by Thursday morning, high pressure sits over the area with clear, calm conditions and valley fog. The last of the showers with the initial cold crossing first thing Monday morning, mainly in the mountains, will be gone by midday, save for perhaps southwest Virginia, where there may be a brief opportunity for an early afternoon thunderstorm. The next cold front approaches Tuesday morning and slowly crosses Tuesday. This will limit the chance for radiative cooling and fog Monday night, as clouds and the gradient flow increase, along with the slight chance for showers in the middle Ohio Valley and northern WV. The front crosses slowly enough to allow the chance for afternoon thunderstorms Tuesday, but limited moisture and instability should limit thunderstorm strength and intensity, even with sufficient shear. The same should hold, even to a greater degree, for afternoon thunderstorms with yet another cold front crossing Wednesday. High pressure following the Wednesday cold front builds in late, so the chance for showers goes well into Wednesday night, with very late clearing toward dawn Thursday. No changes to central guidance temperatures, which trend slowly downward through the period, except cooler still in the valleys at the last minute Thursday morning. && .LONG TERM /THURSDAY THROUGH SUNDAY/... As of 530 AM Sunday... Another upper level low, dumbelling around the first near James Bay, Canada early on, sails southeastward, and then eastward across south central and then southeast Canada this period, maintaining the long wave trough position in the east. The period starts dry, with a warming trend ahead of a surface system associated with the upper level low. That system is progged to bring showers and thunderstorms back into the area on Friday. Models diverge in details after that, but generally concur on another upper level low or short wave trough keeping the baroclinic zone in or near the area, with another surface wave crossing. This keeps the weather unsettled again next weekend. Central guidance temperatures excepted, which show highs remaining near normal and lows inching above normal, although the MEX is higher on highs, getting into the lower to mid 80s in the lowlands, Friday and Saturday. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... As of 130 PM Sunday... More convection expected today, with the greatest coverage over the eastern two thirds of the area. Formation occurring over the southern mountains which could affect the BKW area over the next couple of hours. As typical, TSRA can bring IFR visibilities to the terminals. Add TSRA to the northern terminals tonight with frontal passage. Ceilings to IFR late tonight in the wake of the frontal passage, slowly improving Monday. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z MONDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing and development of convection this afternoon may vary from forecast. Development of IFR or worse conditions late tonight somewhat uncertain. 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 H H H H M H H H H H M L EKN CONSISTENCY H H H H H H H H H H H L PKB CONSISTENCY H H H H H H H H H H M L CKB CONSISTENCY H H H H H H H H H H M L AFTER 18Z MONDAY... IFR possible in isolated TSRA Tuesday and Wednesday.. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Flash Flood Watch through Monday morning for WVZ005>008- 013>020-024>034-039-040-515>526. OH...None. KY...Flash Flood Watch through Monday morning for KYZ102-103-105. VA...Flash Flood Watch through Monday morning for VAZ003-004. && $$ SYNOPSIS...TRM/26 NEAR TERM...26 SHORT TERM...TRM LONG TERM...TRM AVIATION...26 is the U.S. government's official web portal to all federal, state and local government web resources and services.