Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 271034 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 634 AM EDT Thu Jun 27 2019 .SYNOPSIS... Weak high pressure remains today, but a hotter and more humid day lends to a slight chance of storms. Somewhat higher chances for afternoon and evening storms return Friday into next week. && .NEAR TERM /THROUGH TONIGHT/... As of 630 AM Thursday... No changes made to the forecast at this time; satellite shows widespread river valley fog across southern and interior West Virginia, southwest VA, and in some portions of the Tristate of KY/WV/OH. As of 315 AM Thursday... Same general weather set up today as yesterday, with weak high pressure centered over southern Appalachia. Temperatures reach upwards of 90 for portions of the Ohio Valley and western lowlands with muggy dew points near 70. The caveat to high pressure today is that with warmth and moisture continuing to trend upward, corresponding with increased ridging into the Plains, instability grows, paving the way for scattered convection in spite of weak shear and dynamic fields. A disturbance in the NW flow separating us from the growing ridge offers a bit of surface convergence in the Ohio Valley, which would serve as the focus for any convection this afternoon and evening, along with the elevated heat source of the mountains to some extent. Weak winds through the column don`t leave much in the way of storm motion or organization, strong instability in the neighborhood of 3000 J/kg MLCAPE will lead to explosive development, and PWAT around 1.5" will lead to at least localized heavy downpours where low level convergence is maximized. Overall, expecting isolated to scattered, slow-moving, short-lived convection. While wind profiles don`t support significant hail growth, heavy rain and DCAPE exceeding 1000 J/kg supports at least isolated gusty winds under cells. Tonight, enough moisture may pool near the weak wave over the Ohio Valley to create some low-level stratus, otherwise expecting another humid night with at least patchy fog except where low- level clouds form. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... As of 249 AM Thursday... Little change to previous forecast reasoning. Height fields are prog to be the highest on Friday with a hot, humid, and stagnant air type of day. Heat indices may briefly flirt with advisory levels in the immediate downtown urban areas, but most areas in general should remain below Heat Advisory thresholds. If temps warm enough, then isolated diurnally driven afternoon/early evening convection may occur. Height fields lower slightly on Saturday and moisture depth in the atmospheric column is prog to be slightly greater. Thus, slightly higher convective coverage may occur in the afternoon, especially in near the mountains...with hot and humid conditions prevailing again across the region. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... As of 257 AM Thursday... CWA becomes located on the northern edge of mid level ridging for much of the Long Term period with several vort maxes advecting across/near the region during this time frame. Combination of these disturbances and daily high heat/humidity should result in convective chances nearly every afternoon and evening. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... As of 640 AM Thursday... A couple leftover fog restrictions this morning will lift in the coming hour or so, yielding to prevailing VFR conditions through today. Light and variable winds this morning will increase to 5-10 kts from the west southwest by the afternoon, more westerly at BKW. There is a slight chance for storms this afternoon mainly in the Ohio Valley including HTS/PKB, and to a lesser extent EKN with mountain-based storms possible. At this time only have it included for the Ohio Valley. Tonight, winds go light and variable by 00Z and calm shortly after sunset. Look for another night of river valley fog perhaps impacting TAF sites should it be deep enough; guidance also hints at the development of low-level stratus across the Ohio Valley. At any rate, another night of restrictions is possible. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: High for VFR prevailing during the day Thursday. Medium for restrictions tonight. ALTERNATE SCENARIOS: Timing and duration of fog/low stratus tonight may vary. A non-zero threat for storms exists at every site, and storms would produce brief drops in visibility and gusty winds. 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 10 11 12 13 14 15 16 17 18 19 20 21 EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY L M L L H H H H H H H H HTS CONSISTENCY M M L L H H H H H H H H BKW CONSISTENCY H H H H H H H H H H H H EKN CONSISTENCY M M L M H H H H H H H H PKB CONSISTENCY L M L M H H H H H H H H CKB CONSISTENCY L L L H H H H H H H H H AFTER 12Z FRIDAY... IFR possible in afternoon and evening storms Friday into the next week. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RH/MC NEAR TERM...MC SHORT TERM...RH LONG TERM...RH AVIATION...MC

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