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 210717 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 317 AM EDT Sat Oct 21 2017 .SYNOPSIS...
-- Changed Discussion --
High pressure continues through the weekend with mostly clear skies. A strong cold front and low pressure system crosses early next week, with much cooler weather midweek.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH TONIGHT/... As of 255 AM Saturday... Temperatures will be a bit warmer today than what we saw the last few days. High pressure slowly drifts eastward today and low level flow switches around to the SW...hence the warmer temps, but we will continue to see mostly clear skies, other than some cirrus passing through from the west. Also, looking at some warmer temps overnight with dew points coming up a bit with the warm moist SW flow. Tonight we will see the possibility for valley fog once again, but otherwise a nice night overall. && .SHORT TERM /SUNDAY THROUGH TUESDAY/...
-- Changed Discussion --
As of 315 AM Saturday... High pressure departing to the NE to start the period as a strong cold front approaches from the west. Slowed down POPs a bit on the front side...keeping the Sunday night period dry. Then have POPs rapidly increasing Monday afternoon with 80-90 POPs late Monday evening and Monday night. Models still struggling a bit with the location of the surface low and cold front, but both GFS and ECMWF pointing to a rainy night. The ECMWF has the front through the forecast area by 12Z Tuesday, while the GFS is a bit slower with the front still crossing the mountains around that time. This appears to be due to the GFS closing off a southern stream upper low over the lower Mississippi River Valley, while the ECMWF keeps it open and more progressive. No strong feeling either way at this point, so stayed close to the consensus blend.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
-- Changed Discussion --
As of 315 AM Saturday... With the cold front to the east to start the period, attention turns to the trailing upper level trough. The trough axis should be crossing the forecast area early Wednesday, so have lingered chance POPs through most of the day -- envisioning scattered showers as the cold air filters in. GFS continues to be colder than the ECMWF at 850mb -- and have included some snow flakes across the northern mountains both Tuesday night and Wednesday night. Surface temperatures much colder by mid week as well, with highs on Wednesday generally in the 40s and low-mid 50s.
-- End Changed Discussion --
&& .AVIATION /07Z SATURDAY THROUGH WEDNESDAY/... As of 145 AM Saturday... High pressure has pushed over the region and low level winds are weaker early this morning than they were last night. However, there remains a lot of uncertainty on how much valley fog will develop. Forecast model guidance is not interested in any fog until most recent runs pinning IFR fog at EKN around sunrise. Decided to use UPS Crossover technique for this mornings fog forecast, and although guidance is not indicating fog, EKN and HTS should at the very least hit their crossover temperatures, so have only included IFR conditions at those locations. CRW will be a bit tougher to fog so have left at MVFR for now. VFR conditions are expected through the day Saturday with dry high pressure remaining over the area. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: Medium overnight. ALTERNATE SCENARIOS: IFR or worse fog is still uncertain at this time. 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 10/21/17 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 H M L H H H H M HTS CONSISTENCY H H H H H H H H H H H M BKW CONSISTENCY H H H H H H H H H H H M EKN CONSISTENCY H H H L L L L M H H H M PKB CONSISTENCY H H H H H H H H H H H M CKB CONSISTENCY H H H H H H H H H H H M AFTER 06Z SUNDAY... Dense valley fog possible Sunday morning. Heavy rain at times early next week could also bring IFR conditions. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...MZ/MPK NEAR TERM...MPK SHORT TERM...MZ LONG TERM...MZ AVIATION...MPK

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