Area Forecast Discussion
Issued by NWS Charleston, WV

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621 FXUS61 KRLX 270534 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 134 AM EDT Sat May 27 2017 .SYNOPSIS... Weakening MCS moves into the area early Saturday. Storms Saturday with a frontal boundary and high instability. Another Thunderstorm complex on Sunday followed by a cold front Sunday night into Monday. && .NEAR TERM /THROUGH TODAY/... As of 1000 PM Friday... Upped PoPs and QPF overnight as radar indicates a better line of storms (MCS) moving through eastern Indiana and western Ohio and expect those to make it to our forecast area though should weaken before arriving. Speeds suggest arrival into our forecast area by 1 am. SPC MCS maintenance parameter suggests best air south of line which may act to pull the MCS further south than previously forecast...perhaps into the Huntington/Charleston metro areas though not confident in this. As of 800 PM Friday... Not much change, severe threat for tomorrow doesn`t look as good as the water threat, but still bears watching closely. As of 225 PM Friday... Synoptically, flow aloft will turn zonal tonight, while a warm front pushes northward. Awaiting a cold front dropping back southward through the CWA Saturday as a result of a surface wave passage. High res and synoptic models remain keen on the development of a MCS in northern Illinois/Indiana later this afternoon and evening, tracking into middle/upper Ohio Valley. Biggest question here is the exact track with the high res models taking the southern extent closer to the I-64 corridor, despite steering flow suggesting that it should stay a bit further north. Concentrating those POPs tonight along US 50, but this complex will likely be on the wane as it enters the CWA, or shortly after. Atmosphere should have plenty of time to recover after dawn in the warm sector. CAPE values are in line with the frontal position as expected, and with the cold front sinking southward through the afternoon, this should be a southern two thirds of the CWA severe/water event. Will need to carry slight to low chance however north of the boundary. Decent 0-6km flow around 40kts and instability warranting the slight risk for the area south of the front, with the enhanced area closer to our area from the latest SPC issuance. Water cannot be ignored either. Very saturated in terms of surface conditions and creek/stream levels, and any sort of repetitive activity will cause problems. Flash flood guidance values are quite low given the recent wet trend. Convective activity Saturday will largely dictate the weather heading into Saturday night and Sunday. && .SHORT TERM /TONIGHT THROUGH MONDAY/... As of 245 PM Friday... Models still showing a disturbance moving through the area early Sunday. Depending on the timing of the system, could see enough recovery for afternoon thunderstorms. A cold front then pushes through Sunday night into Monday. With the ground so saturated, still concerned with the potential for flash flooding. Will highlight heavy rain in the forecast wording. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 245 PM Friday... An upper level trough will dominate the weather for Monday night through Thursday. This will provide relatively cool weather. A reinforcing cold front moves through on Tuesday, followed by another front Wednesday into Thursday. Models have quite a bit of variability in the timing of the later front. Some showers are possible with both these systems. Model differences become even greater by Friday, leading to considerable uncertainty in the forecast. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
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As of 125 AM Saturday... weakening convection across southeast Ohio and northern WV through 10Z. Expect brief MVFR conditions, and gusty winds up to 30 kts with passage, affecting sites KPKB and KCKB, possibly KEKN if able to hold together. Otherwise, VFR conditions initially, although convection will develop once again, particularly after 18Z, with MVFR and IFR conditions, heavy rain, and strong-damaging winds in vicinity of storms. Bulk of convection will diminish after 03Z Sunday, however, widespread MVFR and IFR conditions are possible in post rain stratus or fog. ALTERNATE SCENARIOS: Timing and location of convection today may be different from current 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. DATE FRI 05/26/17 UTC 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16 EDT 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12 CRW CONSISTENCY H M H M H H M M H H H H HTS CONSISTENCY M H H M H H H H H H H H BKW CONSISTENCY L M L M M L M M H M M L EKN CONSISTENCY M L M L L L L M H H H L PKB CONSISTENCY H M H H H H H H H H H H CKB CONSISTENCY H M L M L H M L H H H M AFTER 06Z SUNDAY... IFR likely in storms Sunday and Monday.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RPY/JW/SL NEAR TERM...JW/26 SHORT TERM...RPY LONG TERM...RPY AVIATION...SL is the U.S. government's official web portal to all federal, state and local government web resources and services.