Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 201438 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 1038 AM EDT Thu Oct 20 2016 .SYNOPSIS... Stalled boundary over Central Ohio heads east as cold front this evening, exiting mountains late tonight. Precipitation lingers Friday, possibly Saturday. Moisture starved cold front Sunday Night. && .NEAR TERM /THROUGH TONIGHT/...
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As of 1030 AM Thursday... Tightened up the POP gradient as more near term, hi-res guidance becomes available. Models still generally showing decent agreement of thunderstorms entering the CWA from the SW late morning into this afternoon. This pre-frontal band of convection will move east across the forecast area into this evening. Projected CAPE is not overly impressive, however a good shear max moves through SE Ohio and north central WV this afternoon and evening which should allow some organization of storms. This matches well with SPC upgrade to slight for the Upper Ohio River Valley. Damaging winds are the most likely threat as best low level shear will remain north of CWA closer to the warm front/stationary boundary. As of 200 AM Thursday... The frontal boundary as of 02Z was generally just north of the OH River. Examining IR satellite imagery shows several organized areas of convection along this boundary, extending back into MO. Surface analysis shows a surface wave located in far southwest KY, and it is this feature that we will be tracking today as it traverses along the boundary. With a good model consensus on little to no activity this morning...elected to go with a drier forecast areawide thru the late morning hours, but still holding on to a low pop across SE OH. By this afternoon the surface wave will have moved off to the north. This should allow the boundary to slip back to the south some into southern OH. With daytime heating and increasing upper level jet dynamics with the approaching s/w trof...expect scattered showers and storms to develop across southern OH and central KY...moving into WV by late afternoon. Some of the storms could be on the strong side as the winds aloft increase. Some modest instability will be realized across the WV lowlands given higher dewpoints and heating. This combined with increasing winds aloft, will support the potential for some strong to perhaps severe storms in fast moving segments, primarily across the southern and central Lowlands late this afternoon. The primary threat would marginally severe wind/hail. Further north, closer to the warm front, better shear will be present so that any instability that is realized could support some rotating updrafts. By this evening, the surface wave will have moved into PA with the trailing front finally pushing thru. As this occurs, the upper trof will be catching up to the surface feature and attempting to go negative tilt. The end result is a widespread area of moderate to occasionally heavy rains developing over the region tonight which may end up being on the cool side of the surface front which will be east of the area after midnight. Thankfully, the area as a whole is still really dry, so no widespread flooding issues are anticipated. QPF looks to run 1 to 2 inches areawide, so a much welcome rain for many.
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&& .SHORT TERM /FRIDAY THROUGH SATURDAY/... As of 245 AM Thursday... Models in agreement with a precipitation band lingering behind the cold front on Friday. For Friday night into Saturday, lingering low level moisture and a northwest wind flow may continue to squeeze out some light rain or drizzle...more likely in the mountains. Any remaining precipitation should end late Saturday as cold air advection shuts off. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... As of 245 AM Thursday... Models show a moisture starved reinforcing front moving through late Sunday or early Monday. Considerable differences between the models with this feature. Will keep some slight chance pops. High pressure then builds in and remains into mid week. Another cold front approaches later in the week. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... As of 645 AM Thursday... VFR conditions thru at least the early afternoon hours. By that time a surface wave will have traversed along or north of the OH River. Showers and storms will develop as it does so, affecting non mountain terminals, primarily KHTS/KCRW. Given a lower confidence, elected to stick to VCTS with shra after 20Z. Some of the storms could be strong to perhaps severe. Widespread rains develops tonight as the front moves through, with cigs and vsby lowering into IFR. Light and variable surface flow will become south today, as a front stalled over the area pushes north first this morning. Light south to southwest flow aloft will become moderate by dawn Thursday and remain so throughout the day Thursday. A noticeable wind shift with frontal passage tonight. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Fog in sheltered valley locations could vary thur 12Z depending on whether flow fully decouples, and on clouds. Thunderstorms may also impact TAF sites Thursday afternoon and 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 10 11 12 13 14 15 16 17 18 19 20 21 EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 CRW CONSISTENCY M L M H H H H H H H M M HTS CONSISTENCY H H H H H H H H H H M M BKW CONSISTENCY H H H H H H H H H H M M EKN CONSISTENCY L L L L H H H H H H M M PKB CONSISTENCY L L M M H H H H H H M M CKB CONSISTENCY M M M M H H H H H H M M AFTER 12Z FRIDAY... IFR possible in rain after 06Z...with low ceilings and some showers lingering into early Friday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...RPY/30 NEAR TERM...MZ/30 SHORT TERM...RPY LONG TERM...RPY AVIATION...30 is the U.S. government's official web portal to all federal, state and local government web resources and services.