Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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028 FXUS61 KRLX 031634 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 1234 PM EDT Wed Jul 3 2024 .SYNOPSIS... High pressure brings dry weather through this afternoon. Chance of rain arrives late this afternoon and tonight. More active weather is expected July 4th and Friday with cold fronts. && .NEAR TERM /THROUGH TONIGHT/... As of 948 AM Wednesday... Minimal updates were made in this morning`s update. Remember, a Heat Advisory will be in effect for parts of NE KY, SE OH and portions of WV from noon through 8 PM this evening. Keep heat safety in mind, and remember to drink plenty of hydrating fluids today. As of 307 AM Wednesday... Key Points: * Heat Advisory in effect for portions of NE KY, SE OH and central, northern southern and western WV from noon through 8 PM this evening. * There is a marginal risk for severe weather over SE OH through tonight. * There is a marginal risk for excessive rainfall over SE OH through tonight. Today, dry weather conditions remains under the influence of a high pressure located off the Mid Atlantic coast. South to southwest flow will bring warm and moist air advection, destabilizing the atmosphere ahead of an approaching cold front. This cold front stalls just to our west, keeping the area under the warm sector. Dewpoints are expected to rise into the lower 70s. With afternoon temperatures reaching the mid 90s across the lowlands, heat index values may exceed 100 this afternoon over NE KY, SE OH and portions of the WV lowlands. Therefore, a heat advisory has been issued for portions of NE KY, SE OH, and central, northern, southern and western WV through this evening. A passing upper level short wave will provide the necessary forcing to trigger convection late this afternoon and evening. Under an environment of SB CAPE values of 1,500 to 2,200 J/Kg, deep layered shear from 20 to 30 knots, and PWATs increasing from 1.5 to 2.22 inches, expect strong to severe convection developing mainly during the late afternoon and evening hours. Local soundings show tall/skinny CAPE signatures. Together with PWATs exceeding 2 inches, thunderstorms will be capable to produce very heavy downpours along their path. WPC has outlooked SE OH under a marginal risk for excessive rainfall through tonight. Hi-res CAMs suggest strong convection reaching the Mid OH valley around by 21Z or 00Z Thursday, spreading east across WV while dissipating. Consequently, SPC has placed SE Ohio in a marginal risk of severe thunderstorms for this timeframe. A more stable atmosphere will remains in WV, northeast KY, and southwest VA suppressing any convection that manage to survive over these areas later tonight. The south-southwesterly wind will make it a hotter day with temperatures reaching the lower 90s in the lowlands. A muggy night is anticipated with temperatures and dewpoints from the mid 60s mountains, into the lower 70s lowlands. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... As of 200 AM Wednesday... Key Points: * Rounds of showers and thunderstorms Thursday with cold front. * Some storms could be strong or severe. * There is a marginal risk for severe weather Thursday. * There is a marginal risk for excessive rainfall on Thursday. Stationary front across Ohio gains some steam and slowly moves eastward across the area Thursday. Showers and storms will overspread the area as through out the day as it makes its eastward journey. Some storms will be strong or severe with damaging winds and maybe some hail. SPC has the entire forecast area outlooked for a marginal risk of severe weather. NAM shows some fairly impressive CAPE (SB,ML and MU) profiles between 1,000-3,000 J/Kg across the area Thursday during peak heating. Values greater than 3,000 J/Kg could exist in a CAPE bulge across the southern coalfields in the afternoon and this could be an area to watch for higher risk of severe thunderstorms. Some uncertainty exists with whether these values will come to fruition as cloud cover could exist throughout the day preventing temperatures from being too hot and creating a cap for any strong convection. Regardless, temperatures look to be in the mid to high 80s across the lowlands with the mountains ranging between the mid 70s and mid 80s. These temperatures will be dependent on the amount of clearing that occurs. Surface to 500MB bulk shear looks to remain confined across our SE Ohio counties and along the Ohio River until later in the afternoon as the front and surface low push through. Values are forecasted to be between 30-45kts across this area, which is decent enough to maintain storm longevity and provide at least a minuscule tornado threat depending on the positioning of a surface low or vort max; the main threats remain to be damaging winds and small hail though. Heavy rainfall will be the main concern with this system as it is slow moving and precipitable water will be around 2.00" inches across the bulk of the area, which is a decent amount of water. As a result, LCLs look to be fairly low (500 to 1,000 meters)resulting in lower cloud bases. Localized to isolated flash flooding issues will be on the table, especially for areas that receive a lot of rain Wednesday night. WPC has the entire area outlooked for a marginal risk of excessive rainfall on Thursday. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 1230 PM Wednesday... With a cold front off to the east Saturday morning, any lingering precipitation over eastern West Virignia and southwestern Virginia will tapper off. A high pressure system will then build over the area, providing seasonable temperatures for Saturday afternoon. The high will provide dry weather for Sunday, with temperatures increasing slightly. As the high shifts off to the east on Monday, some southerly moisture will allow for a chance of showers and thunderstorms, along with above normal temperatures. Models diverge some for Tuesday, with some showing a cold front Tuesday or Tuesday night, while others keep the front to our north. Either way, moisture over the area should allow for a decent chance of showers and thunderstorms. && .AVIATION /16Z WEDNESDAY THROUGH SUNDAY/... As of 601 AM Wednesday... Widespread VFR conditions will prevail at all terminals through at least 21Z or 00Z Thursday. Most of the area will remain dry through the afternoon hours. Then, convection will fire up ahead of an approaching cold front across SE OH by late afternoon into the evening hours. Any strong shower or thunderstorms will produce brief periods of IFR/LIFR conditions along their path. Terminals most likely to be affected will be PKB, HTS and CRW around 00Z and thereafter. Thunderstorms will weaken to just showers as they move into a more stable environment over the eastern terminals. With the frontal boundary stalled west of the area, showers and storms, and associated brief IFR conditions, may still be possible tonight, as a series of upper level shortwaves pass by. Winds will be light southwest with occasional gusts in the teens possible after 15Z. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z THURSDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Convection may develop around 21Z bringing restrictions at least to PKB before 00Z this evening. 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 THURSDAY... Brief IFR possible in showers and thunderstorms Thursday and Friday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Heat Advisory until 8 PM EDT this evening for WVZ005>009- 013>015-017-025-026. OH...Heat Advisory until 8 PM EDT this evening for OHZ066-067-075- 076-083>087. KY...Heat Advisory until 8 PM EDT this evening for KYZ101>103. VA...None. && $$ SYNOPSIS...RPY/ARJ/LTC/JMC NEAR TERM...ARJ/JMC SHORT TERM...LTC LONG TERM...RPY AVIATION...ARJ