Area Forecast Discussion
Issued by NWS Charleston, WV
Issued by NWS Charleston, WV
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205 FXUS61 KRLX 061505 AFDRLX AREA FORECAST DISCUSSION National Weather Service Charleston WV 1105 AM EDT Thu Jun 6 2024 .SYNOPSIS... Cold front exits by late morning. Another cold frontal passage this late afternoon promoting isolated shower and thunderstorm activity. Cooler/drier Friday into Saturday. && .NEAR TERM /THROUGH TONIGHT/... As of 1100 AM Thursday... Radar imagery shows how mostly showers exit east of the Appalachians late this morning. Water vapor satellite imagery and local soundings reflect very dry air aloft, allowing skies to clear from west to east early this afternoon. However, diurnal heating and limited low level moisture will allow for an afternoon cu field to develop. Showers and storms still expected to develop ahead of an approaching cold front this evening. Any shower/storm that manage to develop will be rather weak and low topped. Therefore, Adjusted low PoPs, describing the isolated nature of convection. Rest of forecast remains on track. As of 145 AM Thursday... With frontal passage through the area by late morning chances of precipitation will taper off and become confined to and along the mountains. Clouds will clear out behind the front, but will fill back in slightly for the afternoon when a Cu deck is forecast to form although will have breaks in cloud coverage. Looking at soundings, modest shear will be available due to a relatively weak mid level jet, along with some instability from getting to the low 80`s across most of the area and along with breaks in cloud coverage, this all should be enough to develop and sustain shower activity during the afternoon and evening. However, thunderstorm activity will have low probability due to having mid level caps in the soundings along with dry air in the mid to upper levels. The feature that will help promote thunderstorm activity will be another weak frontal boundary parented by the upper level low just to our north. This boundary of convection will advect in from the west and drive east through the late afternoon and into the evening. This will provide enough moisture and lift to enhance shower activity to thunderstorms although will likely be isolated in nature and also will likely be low topped weak storms. This should be the last thing to affect us from the low to the north before it kicks out toward the east late tonight into Friday. Hi-res models support this solution so it was added into the forecast. Thereafter, clouds clear out nicely and although surface flow may stay slightly elevated enough to deter some fog formation, it will likely form along the mountains and may spill into parts of the lowlands, but not thinking anything dense as of now. One last thing to mention is the fact that PWATS are still high along with low level moisture and lapse rates and not to mention DCAPE which could help some showers become heavy at times so the single threat may be isolated flash flooding. This will be possible under heavy convection, especially under training conditions, across low lying or flood prone areas, but this would be very isolated in nature. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... As of 230 AM Thursday... Post frontal northwesterly flow will yield a somewhat breezy but dry day Friday as cooler and drier air filters into the region. A frontal inversion will keep any stratocumulus/cumulus tops no higher than around 8kft - couldn`t completely rule out a stray sprinkle out of these clouds - especially across the north closer to energy rotating around an upper low stationed over the Lower Great Lakes, but no accumulating precipitation is expected given the limited growth zone for hydrometeors. Surface flow shifts more westerly through the day Saturday in response to a relatively weak wave emerging from the Central Rockies. This will allow moisture to start to build back into the region Saturday afternoon into Saturday night. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 230 AM Thursday... Low pressure over the Lower Great Lakes finally kicks out Saturday night into Sunday dragging a cold front through the region during the day Sunday yielding some light showers. In the wake of this feature, drier air is expected into mid-week, with heat and humidity slowly returning toward the end of the week. This will yield slowly increasing chances for diurnally driven convection. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... As of 730 AM Thursday... By late morning into the early afternoon most activity will be confined along the mountains. All sites are forecast go to VFR by the late morning to the afternoon. One caveat is that another cold front, although weak, will pass through this late afternoon and into the evening promoting more shower and storm activity although will be isolated in nature. This may affect sites with temporarily MVFR conditions, but by the evening things will taper down and VFR will then dominate again. There will be possible fog development along the mountains Friday morning but not thinking it will be widespread enough to affect sites other than EKN at this time, however due to recent rainfall more sites may be affected, therefore placed fog into the TAFs at all sites except for BKW. Surface flow may be enough to suppress a lot of fog, but places where it decouples they will be greater chances for fog. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: High. ALTERNATE SCENARIOS: Restrictions will vary and temporarily bring down sites during frontal passage for the afternoon into the 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 M M H H H H H H H H H H HTS CONSISTENCY M H H H H H H H H H H H BKW CONSISTENCY H H H M H H H H H H H H EKN CONSISTENCY H H M H H H H H H H H H PKB CONSISTENCY M M H H H H H H H H H H CKB CONSISTENCY M M H H H H H H H H H H AFTER 12Z FRIDAY... No widespread IFR conditions are expected at this time. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JP/JZ NEAR TERM...ARJ/JZ SHORT TERM...JP LONG TERM...JP AVIATION...JZ