Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 220619 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 219 AM EDT Sat Jul 22 2017 .SYNOPSIS... Strong to severe thunderstorms possible this weekend. Frontal system passes early next week. Cooler high pressure crosses midweek. && .NEAR TERM /THROUGH TODAY/... As of 200 AM Saturday... Cluster of thunderstorms has moved southeast from southern OH to CRW vicinity and updated grids accordingly. HRRR has shown a steady weakening trend but storms have been more persistent. Recent radar and IR satellite trends have indicated a weakening in intensity/warming tops as outflow runs out ahead of the storm cluster. That said, there has been a slight uptick in coverage to the north/east of CRW with some hints of new cells forming to the south of CRW along the outflow boundary. If showers developing along southern flank of outflow can hold together they may approach BKW area by 08z, but pcpn probs are higher to the north across Clay-Nicholas counties. Once this area of precip exits the CWA, high res models keep things mainly dry through the morning. Main concern would then be fog which is already locally dense in some spots. There remains some uncertainty regarding timing of convection later today. Ongoing storms across northern IL/IN are fcst by the CAMs to move east-southeast across OH thru 18z into PA thru 00z Sun. This would put the northern 1/2 to 1/3 of the CWA at greatest risk for severe storms as westerly flow increases aloft. Any outflow from the more organized activity could trigger additional diurnally drive storms further to the south into the WV lowlands. SPC has maintained a SLGT risk across all but the far southern portion of RLX CWA. High PWs along with increasing westerly flow suggests damaging winds as the primary severe threat. && .SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... As of 330 PM Friday... Models differ on timing of a low pressure system moving through the Great Lakes Saturday night through Sunday night. Leaned toward the NAM solution for this period as it seems to have a handle on current features. Upper level system tracks to our north Saturday night into Sunday. As it passes, trailing cold front will push southward across the CWA. With soupy airmass in place, Any showers or Thunderstorms with the front could produce heavy downpours with PWs near 2 inches over much of the area. Low pressure over the plains will finally lift and cross the Great lakes Sunday night Through Monday night. Left over frontal boundary over the region will lift north as a warm front and trailing cold front will push approach the area Sunday Night and exit Monday evening. SPC has us in a slight risk for severe wx Sunday with afternoon heating and lifting frontal boundary along with increasing instability throughout the day. Airmass stays rather soupy and water concerns are defiantly possibility Saturday night through Monday night. WPC has a slight risk of excessive rain for Saturday night and Marginal risk through Monday. && .LONG TERM /TUESDAY THROUGH FRIDAY/... As of 330 PM Friday... Cooler and drier air associated with high pressure that builds across the region on Tuesday and lasts through Thursday. This will bring a welcome relief from the heat and humidity. Another system or complex may approaches from west Thursday night into Friday. This will bring showers and thunderstorms back into the forecast. && .AVIATION /06Z SATURDAY THROUGH WEDNESDAY/... As of 200 AM Saturday... Cluster of Tstorms impacting CRW vcnty at 06z should move away from the terminal by 07z. Expect isolated convection to persist moving east-southeast from CRW through 09z. Odds are BKW will be spared but did include VCSH to account for any showers that may form along leading outflow. Abundant low level moisture and partial clearing skies and light/calm surface winds should result in dense river valley fog. For the most part maintained continuity from previous 22/00-03z TAFS with IFR/LIFR conditions at most sites through 12z. For Saturday, more unstable conditions compared with this afternoon are expected with the stationary frontal boundary to our north. Therefore, expect scattered to numerous showers and thunderstorms to produce brief periods of IFR/LIFR due to heavy rain along their patch particularly after 16Z. Strong gusty winds, along with small hail will be possible with any storms. More storms on Sunday. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Additional convection could develop early this morning. Widespread fog may not form overnight into early Saturday morning. 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 07/22/17 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 M M M M M M M H H H H M HTS CONSISTENCY M M M M M M M H H H H M BKW CONSISTENCY M M M M M M M H H H H M EKN CONSISTENCY M L L M L L L M M M H M PKB CONSISTENCY L L L L L L L M M H L L CKB CONSISTENCY L L L L L L L M M M M M AFTER 06Z SUNDAY... IFR possible Saturday night and Sunday in heavy showers and thunderstorms. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...None. OH...None. KY...None. VA...None. && $$ SYNOPSIS...JS/SL/99 NEAR TERM...99 SHORT TERM...JS LONG TERM...JS AVIATION...99 is the U.S. government's official web portal to all federal, state and local government web resources and services.