Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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534 FXUS61 KRLX 031722 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 122 PM EDT Wed Jul 3 2024 .SYNOPSIS... High pressure brings hot weather 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 THURSDAY/... As of 120 PM Wednesday... A Heat Advisory remains in effect for portions of WV, southeast OH and northeast KY through this evening with heat index values reaching around 100 during the hottest part of the afternoon. Widely scattered thunderstorms will be possible late this afternoon and this evening in southeast Ohio ahead of a 500-mb shortwave. However, 0-6km shear will be weak (only 20-25 kts) and instability will be weak to marginal (MLCAPE 500-800 J/kg). Thunderstorms should lose intensity as they approach and track east of the Ohio River, where the instability will be even weaker. Severe weather potential will be a little greater Thursday with models showing MLCAPE reaching 1,000-1,200 J/kg in parts of WV and northeast KY. 0-6 km shear is still expected to be fairly weak (only around 25 kts in most spots). As ripples of 500-mb vorticity approaches from the west, a few severe thunderstorms will be possible during the day, with the main threat being damaging winds. With weak shear over most of the area, severe thunderstorms may have difficulty organizing, potentially causing them to be short lived. The SPC currently has a marginal risk of severe weather over the region for Thursday. In addition, there is a marginal risk of excessive rainfall. PWATs are projected to be anywhere from 1.8-2.2 inches across the region, which can lead to heavy downpours. We will have to watch for the potential for localized flooding if thunderstorms begin to train over the same areas. && .SHORT TERM /THURSDAY NIGHT 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 /17Z WEDNESDAY THROUGH SUNDAY/... As of 106 PM Wednesday... Conditions will remain mostly VFR into tonight. A stray thunderstorm is possible this evening, with the best chance at KPKB, can briefly reduce visibility to IFR in a heavy downpour. VFR should continue in most spots overnight, but IFR dense fog is expected in the sheltered mountain valleys after 06Z and before 12Z, particularly at KEKN. Scattered showers and thunderstorms will become more likely by mid-to-late morning Thursday. Winds can occasionally gust from the southwest this afternoon at 15-25 kts. Winds should gradually relax overnight. Expect west-southwest winds again Thursday. 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 17 18 19 20 21 22 23 00 01 02 03 04 EDT 1HRLY 13 14 15 16 17 18 19 20 21 22 23 00 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/JMC NEAR TERM...JMC SHORT TERM...LTC LONG TERM...RPY AVIATION...JMC