Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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277 FXUS61 KRLX 021033 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 633 AM EDT Thu May 2 2024 .SYNOPSIS... High pressure brings dry weather with a warming trend today into Friday. A cold front brings showers and storms as it washes out over the area this weekend. Active next week. && .NEAR TERM /THROUGH TONIGHT/... As of 630 AM Thursday... The few areas of fog then developed across portions of the area this morning should dissipate in the next couple of hours this morning. The near term forecast generally remains on track, with no significant changes needed at this time. As of 130 AM Thursday... An upper level ridge remains over the area today while a frontal boundary - initially located near the northwest fringe of the CWA - is lifted further north as a low moves out of the Central Plains and approaches the Great Lakes later today. Dry low-level air should allow dry conditions to persist across the area today, though some mid to high level clouds may continue to drift overhead. Ridging begins to slide east tonight as a cold front slowly approaches from the west. While quiet weather should linger through the night, a gradual increase in cloud cover is expected to occur ahead of the front. After a mild morning, daytime highs are expected to climb into the upper 80s in the lowlands and 70s to 80s along the mountains. Tonight will be mild again with lows likely to be in the 50s to 60s. && .SHORT TERM /FRIDAY THROUGH SUNDAY/... As of 340 AM Thursday... Sustained periods of dry periods are elusive in both the short and long term periods. The short term does start dry, with mid-upper level ridging exiting ahead of a southern stream short wave trough and surface cold front approaching from the west. There are some model differences in whether these features roll into the area Friday midday through evening, or Friday afternoon and night. The latter would allow more dry time and daytime heating Friday, while the former brings clouds, showers and thunderstorms in earlier. The forecast sticks with the later timing. Even so, some increase in cloud during the morning and midday, and modest dew points of around 60 or even lower, will likely contribute to modest instability Friday afternoon, with CAPE less than a KJ/kg. Given modest low to mid level flow/shear, thunderstorms are not expected to be especially strong, but they can produce heavy downpours and gusty winds in the middle Ohio Valley by late in the day. As the system lifts northeastward through the area, the surface cold front washes out, stranding the area in southerly flow of very warm and increasingly humid air amid additional short wave ripples in the mid-upper level southwest flow. Showers and thunderstorms are likely Friday night through Saturday, and even into Sunday. The nearly saturated atmosphere will not be that unstable, but PW values could climb to 1.5 inches or higher, so heavy downpours are a good possibility. However, the growing vegetation and recent dry weather should minimize the potential for high water. By later in the day Sunday, the short wave trough exits, giving way to ridging, lessening shower and thunderstorm coverage Sunday afternoon, compared with Saturday afternoon, at least across the middle Ohio Valley. Unseasonably warm conditions continue Friday as mid-upper level ridging slowly works east of the area. While central guidance highs Friday are 10 to nearly 15 degrees above normal for early May, they are still comfortably below record highs for the date. After a rain-cooled Saturday, perhaps not too unlike Tuesday, highs moderate a bit on Sunday given decreasing shower and thunderstorm coverage. Nights remain unseasonably mild for this time of year. && .LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/... As of 410 AM Thursday... The weather pattern remains active in the long term, but with increasing model uncertainty, particularly with timing. While short wave ridging amd loss of heating will result at least a decrease in shower and thunderstorm coverage Sunday night, another southern stream short wave trough undercutting a larger ridge migrating from the midwest to the Great Lakes arrives first thing Monday morning. This, with what is left of the cold front that washes out this weekend gaining new life as a warm front, showers become likely again Monday afternoon, along with the chance for thunderstorms. Its exit, amd loss of heating, will result at least a decrease in shower and thunderstorm coverage again Monday night, A large mid-upper level low migrates from the northern plains to the Great Lakes next week while becoming elongated west- southwest to east-northeast. Intense surface low pressure over the northern plains Tuesday fills in favor of another center forming over the Great Lakes Wednesday. All this serves to drag the cold front associated with the system closer to the area, keeping the possibility for showers and thunderstorms going. With the pattern a bit more amplified by this time, there may be increased instability ahead of the cold front, giving rise to stronger afternoon and evening thunderstorms, and more opportunity for heavy downpours. In the warm and humid environment heading toward mid May, coverage will be greatest and storms strongest during the afternoon and evening, with the overnight and morning minimum. Southwest mid-upper level flow associated with the elongated low gradually veers to west-southwest through Thursday, gradually nudging a weakening initial cold front into the area, keeping the unsettled weather going. Central guidances reflects a gradual moderation in temperatures next week, getting further above normal and more typical of mid summer than early May. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... As of 630 AM Thursday... The few areas of fog that developed this morning will dissipate in the next couple of hours, then VFR conditions are expected across the area for the rest of the day. While VFR is expected to persist overnight, cloud cover should begin to increase out ahead of a slowly approaching front. Light and variable winds are expected through the majority of the TAF period. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: None. 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 05/02/24 UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20 EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16 CRW CONSISTENCY H M M H H H H H H H H H HTS CONSISTENCY M M 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 12Z FRIDAY... IFR possible in rain and storms Friday night through Saturday, and in stratus and fog Sunday morning. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...TRM/JLB NEAR TERM...JLB SHORT TERM...TRM LONG TERM...TRM AVIATION...JLB