Area Forecast Discussion
Issued by NWS Charleston, WV

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486 FXUS61 KRLX 251617 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 1217 PM EDT Sat May 25 2024 .SYNOPSIS... Cold front arrives this evening, and stalls across our north through Sunday. This will keep showers and storms through Memorial Day weekend. Damaging wind gusts, hail, and locally heavy downpours will be possible. && .NEAR TERM /THROUGH TONIGHT/... As of 1031 AM Saturday... Freshened up temperatures this morning, running a few degrees cooler than anticipated, and sky conditions to reflect passing cirrus as far east as the mountains. Awaiting more hi-res 12Z guidance to aid in preparing this afternoon`s forecast package that will encompass the end of the weekend severe weather concern. As of 208 AM Saturday... Low level south to southwest flow develops ahead of an approaching cold front today. Moisture advection and afternoon heating will destabilize the atmosphere with surface CAPE values reaching 3500 J/Kg under a low to none shear. Local soundings show a dry column within a tall skinny CAPE signature. With PWATs about 1.5 inches, this environment could lead to isolated to scattered slow-moving showers and thunderstorms some with heavy rain and associated localized water issues. WPC has most of the area under a marginal risk for excessive rainfall. In addition, SPC has a marginal risk for strong to severe thunderstorms to develop this afternoon and evening. The main threat will be strong gusty winds and large hail. Allowed chance PoPs for afternoon convection, tapering off by midnight. The aforementioned cold front arrives to the Middle Ohio valley this evening, stalling across our northern sections tonight into Sunday morning. Upper level flow becomes diffluent with no noticeable shortwaves passing tonight. However, cannot ruled out convection activity along the stationary front tonight, but the lack of forcing and heating should keep confidence low. Abundant low level moisture, calm flow and breaks in the sky will allow for radiational cooling and associated dense fog mainly along river valleys late tonight into Sunday morning. Under plenty of sunshine, afternoon temperatures warm up into the mid-80s across the lowlands and the 70s for the higher terrain. Lows tonight will generally be in the low to mid 60s lowlands, ranging into the mid 50s higher elevations. && .SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/... As of 1150 AM Saturday... Showers and thunderstorms remain likely Sunday night and into Monday morning with waves of shortwave energy approaching from the west. The strength and timing of any thunderstorms overnight still remains questionable. Most models show storms weakening as they approach West Virginia from the west, likely due to a lack of instability. Some thunderstorms may be capable of bringing damaging winds and hail, particularly across northeast Kentucky and far southern Ohio, where instability will be a little more favorable. Severe potential is more questionable across West Virgina. Nonetheless, the atmosphere will still have plenty of moisture with PWAT values likely to be anywhere from 1.25-1.75 inches late Sunday night and into Monday morning. Therefore, we are concerned about the threat of flooding, especially in training showers/thunderstorms and locations where the ground has been saturated from previous activity. The Weather Prediction Center places much of the region in a slight risk of excessive rainfall through 12Z Monday morning, which increases our concern for potential high water issues. A cold front will sweep through from the west Monday afternoon. Ahead of the front will be scattered showers and thunderstorms. Therefore, the potential for flooding will continue into Monday. The Memorial Day holiday shouldn`t be a complete washout, but it will be a good idea to keep an eye to the sky and stay up to date with the latest forecast. Mid-level drier air will funnel in from the west behind the cold front Monday evening, which should help curb the flooding threat. Isolated showers and thunderstorms will remain possible Tuesday as an upper-level low spins over the Northeast. The flooding threat for Tuesday and Wednesday looks low at this time. && .LONG TERM /WEDNESDAY THROUGH FRIDAY/... As of 1150 AM Saturday... Showers will remain in the forecast Wednesday, but drier weather should build into the area from Thursday onward as high pressure expands into the middle Ohio Valley. Temperatures Wednesday and Thursday will be much cooler than what we have seen recently. Highs will only be in the upper 60s in the mountains to the 70s in the lowlands. Temperatures should gradually warm back into the 80s again by next weekend as high pressure slides to the east and a southerly flow returns. && .AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
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As of 1215 PM Saturday... Afternoon cumulus field has sprouted across parts of the forecast area at the time of writing, with the bulk of radar activity still outside of our airfields. Mid-level flow will direct showers and storms that attempt to form today to the northeast, so it will require development to the southwest of a TAF site in order for rain and/or thunder to be observed. This remains fairly driven by daytime heating today, so anything that does form will quickly fade off after sunset. Will handle the forecast with VCTS for now with note of potential future AMDs to include tempo groups for brief vsby drops in the event a storm moves overhead. For tonight, there is a strong signal on forecast soundings for fog development early Sunday morning. Light flow through the profile, coupled with increasing low level moisture, will generate widespread fog, locally dense in some spots, for the early morning timeframe. Outside of lower confidence at BKW, opted to carry IFR or worse at all other sites. Fog gradually lifts and erodes after daybreak. Another round of showers and storms will be present on Sunday as an advancing cold front drifts closer to the area. There will be a stronger emphasis on severe weather for the afternoon and evening, so VCTS will be most likely included in future TAF issuances to highlight this potential. Light winds prevail through the period. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Onset timing of fog and its intensity may vary for late tonight into Sunday 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 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 SUNDAY... IFR possible at times in showers and storms through early next week.
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&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...ARJ/JMC NEAR TERM...ARJ/MEK SHORT TERM...JMC LONG TERM...JMC AVIATION...MEK