Area Forecast Discussion
Issued by NWS Charleston, WV

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KRLX 190647 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 247 AM EDT Wed Jul 19 2017 .SYNOPSIS...
-- Changed Discussion --
Upper ridge over the Ohio Valley weakens today, with increasing heat and humidity, and mainly scattered afternoon mountain storms. Convective activity on the increase into the weekend.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TODAY/... As of 1045 PM Tuesday... The last of the showers across far eastern WV and VA are finally diminishing this evening. Expecting close to a repeat performance of last night, with mild and muggy conditions persisting. Fog is likely in river valleys again with clear to mostly clear skies and calm winds. The latest surface observations indicate misty haze starting to develop along the Ohio River and in the Clarksburg vicinity. For Wednesday, an upper ridge will build in with temps once again climbing into the lower 90s and heat indices reaching for the mid to upper 90s under scattered cumulus. Some of the 00Z hi- res guidance is hinting at a small upper impulse approaching the area by tomorrow afternoon/evening and, given the abundant heating, supporting isolated storms. While not out of the question, confidence is low enough as of now to exclude increasing PoPs tomorrow. Regardless, most areas will stay dry and hot with little relief in the humid air tomorrow night. && .SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
As of 235 AM Wednesday... As the 500mb gradient in northwesterly flow drops ever so slowly southward into the CWA, NAM is giving hints of layer moisture pooling along a frontal boundary that will be sagging south simultaneously. While these values can be over exaggerated by this model, the increase in the values is what is significant, putting the CWA back in the cross hairs for heavy rain in convection Thursday night through Friday night. However, the convection will favor the northern two thirds of the CWA, and cap the POPs at chance as the forcing is on the weak side, and the flow really cuts back from Thursday night to Friday. The flow Thursday night will be enough to warrant marginal/slight to dip into the northwest corner of the CWA. Expecting low 70s dewpoints and low to mid 90s highs.
-- End Changed Discussion --
&& .LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
As of 235 AM Wednesday... Upper ridge retreats back to the west as gradual height falls into the Great Lakes will bring an increase in convective activity warranting higher POPs for Saturday through Monday. The ECMWF has had difficulties maintaining any run to run consistency on both the strength and southward extent of the incoming trough aloft as well has the timing of the cold front and its potential passage. Both operational models keep the flow aloft zonal for the weekend. Going with a Monday night frontal passage for now, but figure this detail will meander a bit in coming forecasts. Airmass in its wake could provide a little temporary relief from the current heat wave.
-- End Changed Discussion --
&& .AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
06Z Wednesday thru 06Z Thursday... As of 150 AM Wednesday... Pattern slowly changing today as upper ridge weakens over the Ohio Valley, and weak upper trough over the mountains shifts east. This allows a bit more moisture to spread over the low lands from the west today while there will be a decrease over the mountains as we lose the better moist low level southeast flow. This will lead to some decrease in afternoon convection over the mountains, while the remainder of the area still looks to be stable enough to suppress afternoon convection in spite of the increased moisture. Will basically have lower chance pops in the northern and central mountains this afternoon. Elsewhere, although cannot rule out an isolated afternoon shower with the increasing moisture, it looks like most areas, if not all, will remain precip free. Expect MVFR/IFR river valley fog til around 12Z at most major TAF sites except BKW. Best chance for IFR fog will be at PKB, EKN and CKB. By 13Z all fog has dissipated, leaving the remainder of the day with afternoon SCT CU 4500-6000 feet AGL. Will again include a VCTS for only EKN and BKW this afternoon. Near calm winds early this morning becoming westerly 5 to 8 KTS this afternoon. For tonight, winds go near calm again with dissipation of clouds and any showers early with loss of heating. Any river valley fog would be after 06Z Thursday. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY... FORECAST CONFIDENCE: Medium for fog early this morning. Medium for afternoon convection. ALTERNATE SCENARIOS: Fog timing and extent will likely vary early this morning. May be a bit more afternoon convection over southeast Ohio than 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 WED 07/19/17 UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17 EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13 CRW CONSISTENCY H H H H L M M H H H H M HTS CONSISTENCY H M M M L M M H H H H M BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H M M L L L M H H H H M PKB CONSISTENCY M L L L L L L M H H H M CKB CONSISTENCY H M M M L L M H H H H M AFTER 06Z THURSDAY... Patchy IFR river valley fog is possible Thursday and Friday mornings.
-- End Changed Discussion --
&& .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JMV/26 NEAR TERM...DTC SHORT TERM...26 LONG TERM...26 AVIATION...JMV

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.