Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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461 FXUS61 KRLX 170759 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 359 AM EDT Thu Sep 17 2026 .WHAT HAS CHANGED... Minor adjustments to shower and storm chances through the weekend, but otherwise, the forecast remains on track. In addition, a 06Z Aviation Discussion was issued. && .KEY MESSAGES... 1) A meandering frontal boundary will provide daily shower and storm chances into next week. Storms could be heavy at times, with the main concerns being the potential for localized flash flooding and isolated strong wind gusts. 2) Hot conditions continue today across the lowlands, albeit not as widespread as yesterday. A bit of a reprieve occurs on Friday, with a gradual warming trend for the weekend. && .DISCUSSION... KEY MESSAGE 1... A quasi-stationary frontal boundary continues to meander north of the region this morning across the northern Ohio Valley, resulting in another mainly clear and quiet morning across the forecast area, albeit 5-10 degrees warmer than that of yesterday. A WSW to W low-level feed continues to funnel warm/moist air from the Gulf into the area, pivoting around an upper ridge centered to our southwest across the western Tennessee Valley. This continued moisture return has facilitated slightly more widespread river valley fog this morning, once again primarily south of the Ohio River where BL flow is weaker. A gradual expansion in coverage may continue to occur until dawn, with dense fog possible in the usual areas. The aforementioned frontal boundary will begin to creep southward today as a cold front, gradually crossing through the CWA beginning tonight through midday on Friday. The front is then progged to stall southwest of the area late Friday into Saturday, then quickly buckle back north as a warm front late Saturday and Saturday night, then once again become quasi- stationary just north or across the forecast area into early next week. This all translates into a generally active pattern across the CWA, with daily rain chances amid warm/humid conditions, into at least early next week. The primary concerns with this pattern will continue to be the potential for localized flash flooding and isolated strong diurnal storms at times. A more robust shortwave may eventually help clear the area out from showers/storms sometime mid to late next week. Rain chances will be highly correlated to the position of the frontal boundary, and enhanced by diurnal heating or at times weak crossing upper-level perturbations atop the aforementioned ridge. Given the overall recent wet pattern we`ve been in over the last week or two, and the return of a very moist (Gulf influenced) airmass with progged PWATs pushing 1.7-2.1" at times (00Z ILN RAOB - 2.04"), the concern for flash flooding will return. The period of greatest concern in the near term is later today into tonight with the potential for heavy shower and thunderstorm activity via diurnal heating and a weak crossing upper wave. One hour FFG remains relatively low across most northern zones at less than 1.5", with just slightly higher values further south. CAMs however continue to depict significant spread in progged rainfall amounts, with confidence in placement of any heavier rainfall corridors remaining relatively low. For example, 00Z HREF probabilities of 1.5"/hr in a 25-mile radius are generally less than 10%. While this doesn`t rule out the potential for isolated instances of flash flooding today/tonight, it does result in confidence that is too low for a Flood Watch at this time. WPC has maintained a Marginal Risk for excessive rainfall across much of the area today into tonight. A general reprieve is expected on Friday, with isolated to scattered shower/storm chances across the south and mountains. A mainly dry day is expected on Saturday, with increasing shower/storm chances Saturday night through Sunday as the front lifts back north across the area, with localized flash flooding once again being possible. The other aspect of this pattern will be the potential for isolated strong diurnal thunderstorms at times, once again hinging on the position of the frontal boundary. The general setup will feature modest shear (15-25 kts / 0-6km) and modest buoyancy (750-1,500 Mixed-layer CAPE) amid rather saturated profiles. A few isolated strong storms remain possible this afternoon/evening, main hazard being strong wind gusts via wet downbursts. Additional strong diurnal storm potential could return Sunday or early next week given slightly more favorable progged kinematics, but will once again hinge on the front`s position in relation to the CWA. KEY MESSAGE 2... Oppressive heat and humidity will continue today across portions of the area in advance of the aforementioned cold front across the northern Ohio Valley. Increased cloud cover and rain chances this afternoon/evening will temper the overall coverage of oppressive conditions across the lowlands from that of yesterday, existing today more so across our central/southern zones, where highs will once again reach the upper 80s to low 90s, while mid 80s are expected across the northern lowlands. Have once again lowered dew points from central guidance this afternoon/evening, generally expecting values in the low 70s. The combination of aforementioned temperatures and dew points will result in heat indices this afternoon and early evening reaching the mid 90s to 100 across the central/southern lowlands, with an SPS potentially being issued later to highlight this. Be sure to take frequent breaks if outside during peak heating hours today. Some relief is expected on Friday as the aforementioned cold front gradually slides south through the area, bringing a return to near seasonable values - low/mid 80s across the lowlands. Warmer and more humid conditions, albeit not as bad as today, return over the weekend as the front buckles back north of the CWA. Highs are progged for the mid 80s to near 90 across the lowlands. && .AVIATION /06Z THURSDAY THROUGH MONDAY/... River valley fog continues to slowly expand northward this morning south of the Ohio River. At present, restrictions are progged for CRW/EKN w/ fog, but cannot entirely be ruled out at CKB/PKB. Fog will lift / scatter out from ~ 1130-1300Z this morning. Mainly VFR conditions are expected during the day on Thursday amid a FEW/SCT (030-050) Cu field late morning through the afternoon in some areas. ISOLD to SCT showers/storms are expected as we go through the day, bringing the potential for brief MVFR/IFR VSBY restrictions. Confidence in timing/placement remains low. Given such, have just coded PROB30 groups into the TAFs for the time being during the afternoon/evening. Coverage of showers and storms should lessen some after sunset, although at least some ISOLD activity will continue to be possible. Some patchy valley fog development is possible towards 6Z, especially in areas that receive rain and then some clearing. Calm to light and variable flow is expected for the remainder of the overnight. Light flow is expected on Thursday, generally ranging from WSW to NW. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Fog coverage, timing, and associated restrictions this morning may vary from the forecast. Timing and location of showers and thunderstorms during the day on Thursday will vary from the forecast, with brief MVFR/IFR restrictions possible in showers/storms. 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 THU 09/17/26 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H L L L L L L H H H H H HTS CONSISTENCY H H H L L L H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY L L M M M M M M H H H H PKB CONSISTENCY H H M M L L M H H H H H CKB CONSISTENCY H H L L M H H H H H H H AFTER 06Z FRIDAY... Patchy IFR conditions are possible with river valley fog and/or stratus each morning through the weekend, most likely in and near the higher terrain. Brief IFR conditions could also occur at times into early next week within showers/storms. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ DISCUSSION...GW AVIATION...GW