607 FXUS61 KRLX 260839 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 439 AM EDT Sat May 26 2018 .SYNOPSIS... Strong upper level trough crosses today into Sunday. Dry with high pressure for Memorial Day. Unsettled weather should return by mid week. && .NEAR TERM /THROUGH TONIGHT/... As of 255 AM Saturday... Upper trough approaches the region from the west today. Expect an increase in showers and thunderstorms through the day as low level moisture increases and heights drop with the approaching trough. Instability is looking fairly weak today, with maybe some area topping out with about 800 J/Kg of CAPE. PWATs are slightly anomalous over the region, and with low FFG values across the Northern Forecast Area, we will have to watch for isolated water issues today and tonight. Generally, this system should have minimal impacts to the area, but cell movement will be quite slow with the weak winds aloft. Areal coverage of any one shower or storm will be quite small though, but where they do hit, short bursts of high rainfall rates have the potential to cause flash flooding in the lower FFG areas. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... As of 420 AM Saturday... Models show an upper level wave in H500 vorticity charts passing slowly south Sunday night into Monday. Abundant moisture will continue over the area under generally weak flow. The combination of parameters, together with the afternoon heating will promote shower and storm development more numerous during the afternoon and evening hours. There should be a lull in pcpn activity Monday night as a drier airmass moves over. Therefore, coded chance PoPs with thunder for these conditions during the afternoon and evening hours. Went with the blend of all models for temperatures through the period. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 420 AM Saturday... Bufkit soundings show a saturated column with limited bouyancy and about 20 knots of deep layered shear for Tuesday. Kept PoPs to the extreme southern portions of our CWA for now, and dry conditions across the northern two thirds of the area. These conditions arise as a back door cold front approaches from the northeast, while the remnants of what became the sub-tropical storm Alberto begin to move north out of the Gulf of Mexico. Consistency among run-to-run model provides some confidence that if the remnants of Alberto track our way, it will spread an area of stratiform rainfall with embedded showers due to limited instability despite high moisture presence Wednesday through Thursday. Otherwise, tropical moisture could move south and east of the area. Continued with showers and storms possible Friday with an upper level system somewhere in the Great Lakes region. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... As of 145 AM Saturday... Possible IFR fog tonight at EKN and PKB and possible MVFR fog elsewhere except BKW. EKN is most likely area to see LIFR fog, due to a few light showers that have primed the ground with added moisture. At PKB, confidence is much lower and low level flow may be just strong enough to keep visibility in the MVFR range. A strong upper level disturbance, to more numerous showers and thunderstorms today. Any showers or storms could bring brief IFR conditions if there were to pass overhead, but confidence is too low at this time to say which sites may be impacted. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: Medium ALTERNATE SCENARIOS: IFR fog overnight and early Saturday morning may not develop at PKB and timing of onset may differ at EKN. May need to add TSRA and flight restrictions for numerous cells on Saturday. 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 FRI 05/25/18 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 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 H H H H H H H L EKN CONSISTENCY H H H H H H H H H H H M PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY H H H H H H H H H H H M AFTER 06Z SUNDAY... No widespread IFR expected. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...ARJ/MPK NEAR TERM...MPK SHORT TERM...ARJ LONG TERM...ARJ AVIATION...MPK