Area Forecast Discussion
Issued by NWS Charleston, WV

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000 FXUS61 KRLX 232335 AFDRLX Area Forecast Discussion National Weather Service Charleston WV 635 PM EST Fri Feb 23 2018 .SYNOPSIS... Nearly stationary front meanders about the area into Sunday, as surface waves pass. Areas of significant rainfall possible into the weekend. The front finally charges through on Sunday. && .NEAR TERM /THROUGH SATURDAY/... As of 250 PM Friday... The front that has been oscillating about the area the past few days, surged northward, as a warm front, today. In the warm unstable air, quick-standing convection has fired up, with brief heavy downpours and gusty winds, taking advantage of 45 kts deep layer bulk shear, and nearly a kj/kg CAPE. The convective nature of the precipitation should wane this evening. However, the front sags southward tonight, ahead of several waves that will moves northeastward across the area tonight through Saturday. These frontogenetic waves increase low level convergence along the front overnight tonight, the front and associated convergence then moving back north Saturday, This will bring increasing area coverage of rain, which could be heavy because of elevated convection in strong moisture transport that increases PW values toward 1.25 inches, near the climatological max. Convection may become closer to surface based Saturday, south of the front, with up to 60 kts deep layer bulk shear at times, so strong heavy thunderstorms are possible. Temperatures continue to reflect the baroclinic zone, with daytime insolation south of the front increasing the contrast during the peak heating hours. Guidance was having a somewhat difficult time with this. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... As of 322 PM Friday... east-west oriented stationary front at the beginning of the period should push north of the area Saturday night with a cold front then expected to sweep east on Sunday. As the cold front pushes east, precipitation chances should end from the west. Until the front pushes east, models indicate precipitation chances will remain high with the highest QPF still expected across the southeast Ohio counties as well as the West Virginia counties adjacent to the Ohio River. Current thoughts are that QPF values between 0.75 to 1.25 inches along and northwest of the Ohio River with amounts near 0.50 inches elsewhere. This heavy rain, coupled with the precipitation expected on Saturday, should result in some main stem rivers experiencing flooding on Sunday night and Monday. This is especially true for the Ohio River, where major flooding is forecast along many of our official forecast points. The current forecast levels compare closely to Ivan in 2004, which produced significant flooding along the Mighty Ohio. An area of low pressure is then expected to move northeast along the front, which may be located just to our southeast. This will result in some scattered showers Sunday night into Monday. Temperatures will remain very warm on Sunday, with slightly cooler temperatures Monday. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... As of 322 PM Friday... High pressure will then take control of the weather with dry weather anticipated Monday night into Tuesday night. A warm front will then approach the region on Wednesday resulting in increasing chances for showers. An associated area of low pressure will push east on Thursday dragging a cold front across the area. Most areas should see wet weather Wednesday night and Thursday with decreasing chance of showers by late Thursday. Airmass could become cold enough for some of the precipitation to change over to snow across the highest elevations Thursday night. Went with a model blend for temps. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... As of 115 PM Friday... Radar and satellite images show isolated rain showers over KY and some exiting northeast from WV. However, a large area of scattered to numerous showers along a cold front is evident across central OH. Models suggest this feature will move slowly east to affect portions of southeast OH and WV tonight into early Sunday. With near saturated soils from previous rain, and the slow motion of the cold front, expect this rainfall activity to move over our area to produce IFR/LIFR conditions along with the heavier showers overnight into Saturday. Low level stratus could continue into mid morning Saturday. Then, the cold front will push further south to bring the shower activity over our sites. It is uncertain about the timing of the associated IFR/LIFR conditions at this point. Will code MVFR conditions over the extended part of TAF, coding more details as possible during the first 6 hours of the period. Light and variable wind tonight, will remain light or calm for the most part on Saturday. Moderate to strong southwest flow is expected once again Saturday afternoon. FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY... FORECAST CONFIDENCE: Medium. ALTERNATE SCENARIOS: Timing and degree of lower flight categories may vary with timing of rain, and with possible fog and stratus overnight tonight into Saturday. 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 22 23 00 01 02 03 04 05 06 07 08 09 EST 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04 CRW CONSISTENCY H H H H H H H H H M L L HTS CONSISTENCY H H H H H M H M M H L L BKW CONSISTENCY M M M M M M M M M M L L EKN CONSISTENCY H H H H M L H H H H M L PKB CONSISTENCY M M M M M H H H M H L L CKB CONSISTENCY H H H H M M M M M H L L AFTER 00Z SUNDAY... IFR possible at times in showers Saturday night into Sunday. && .RLX WATCHES/WARNINGS/ADVISORIES... WV...Flood Watch through Sunday afternoon for WVZ005>011. OH...Flood Watch through Sunday afternoon for OHZ066-067-075-076- 083>087. KY...Flood Watch through Sunday afternoon for KYZ101>103-105. VA...None. && $$ SYNOPSIS...TRM/RPY/30 NEAR TERM...TRM SHORT TERM...JSH LONG TERM...JSH AVIATION...ARJ is the U.S. government's official web portal to all federal, state and local government web resources and services.