Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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430 FXUS61 KRLX 202353 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 753 PM EDT Fri Sep 20 2024 .SYNOPSIS... Mostly dry and warm under high pressure. A weak system passes through over the weekend, and may trigger a few showers over and near the mountains on Saturday. && .NEAR TERM /THROUGH SATURDAY/... As of 120 PM Friday... Mostly dry conditions expected tonight as a surface high pressure slides east of the Appalachians. Patchy dense fog will be possible once again, along the most protected river valleys. Any fog will quickly dissipate by 9 AM Saturday morning. A weak shortwave, evident at H700, will push a cold front Saturday morning with isolated light showers, as shown by a few of the deterministic models. Therefore, added low PoPs for the onset of precipitation Saturday morning across SE OH, spreading east across WV through the afternoon. Then, aided by afternoon heating, showers and thunderstorms should develop across the area into the evening hours. Moderate instability with CAPE reaching 1,800 J/kg and PWATs +2 standard deviation from the mean suggest storms may produce localized heavy downpours. In addition, dry air in the mid levels may allow for strong downburst capable to produce damaging winds. SPC has most of the area under general thunder, and a marginal risk for severe thunderstorms across the northeast mountains for Saturday. Tonight`s lows will range from the low to mid 60s lowlands, into the mid 50s northeast mountains. Highs on Saturday will reach the lower 90s across the lowlands, ranging into the lower 70s northeast mountains. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/... As of 952 AM Friday... An upper-level ridge will briefly move over the area Sunday with the return of dry, hot, and sunny weather areawide. Increased fire danger will return Sunday afternoon, especially in the lowlands, with afternoon minimum RH values expected to range from 30-40% across the central and northern WV lowlands and portions of southeast OH. High temperatures will reach the lower 90s across much of the lowlands during the afternoon. Rain chances will slowly increase from west to east Sunday night as 500-mb heights lower and the next low pressure system approaches. The best chance of showers Sunday night into Monday morning will be across southeast Ohio. && .LONG TERM /MONDAY THROUGH FRIDAY/... As of 952 AM Friday... A wave of low pressure will track into the Great Lakes Monday with a trailing cold front moving into the Ohio Valley. This will bring more moisture into the area with afternoon minimum RH only expected to drop to 50-60% across the WV lowlands and southeast OH. This should mitigate the fire threat. In addition, shower chances will return, with the greatest chances across northern WV and southeast OH. The rest of the week looks unsettled with chances of rain just about each day as waves of mid-level vorticity flow along the approaching trough. Given our drought situation, this is good news. Another cutoff upper-level low is expected to develop by the middle of next week, over the midwest or the Great Lakes, with not much movement expected through the end of next week. This should bring daily chances of showers for our region. Confidence is still low at this time, but there is potential for some beneficial rainfall. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... As of 740 PM Friday... VFR conditions should prevail overall through the period, though a weak disturbance could bring some isolated showers and a few thunderstorms to the area, particularly in/near the mountains. However, confidence in timing/location of any convection was too low to include in the TAFs at this time. Aside from any localized restrictions in thunderstorms, the only other aviation concern this period will be for some valley fog in a few spots. Only terminal with high enough confidence to put it in prevailing was EKN, but some fog in the Elk River valley could at least get close to CRW late at night. Winds remain light overnight, and will be SW-W`ly gentle breezes tomorrow afternoon. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing and extent of fog may vary from forecast. 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 SAT 09/21/24 UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11 EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07 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 L L M M M M 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 00Z SUNDAY... IFR conditions possible Sunday morning along the higher terrain from river valley fog. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...FK/ARJ/JMC NEAR TERM...ARJ SHORT TERM...JMC LONG TERM...JMC AVIATION...FK