Area Forecast Discussion
Issued by NWS Wilmington, OH

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000 FXUS61 KILN 230613 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 113 AM EST Fri Feb 23 2018 .SYNOPSIS... Copious moisture will combine with multiple weather disturbances riding along a slow moving front to produce heavy rainfall and flooding tonight through Saturday. Dry weather is expected with the arrival of high pressure Sunday through Tuesday. Above normal temperatures are forecast to persist through the period. && .NEAR TERM /THROUGH TODAY/... Our region remains in a relative precipitation lull this evening. Have added areas of drizzle occurring in saturated shallow moisture, a precursor to rain arriving later tonight. An embedded s/wv in a very moist southwest flow aloft will interact with a northward moving warm front overnight. A decent LLJ will develop to our southwest, and this will impinge on the warm front, producing substantial moisture convergence. As a result, showers will develop and increase from our southwest late. Models are also showing at least elevated instability, so a chance of thunderstorms is also mentioned. With PWATs forecast to approach 1.50 inches (which is typical of July and about 3 sigma values above climo) the potential for moderate to heavy rainfall exists. Points along and south of the Ohio River have already received 1 to 3 inches of rain today. Thus, any additional rainfall will likely go directly into runoff due to saturated soils, resulting in continued or renewed flooding. Based on model QPF foot prints, the threat for moderate to heavy rain may affect locations along the I-70 corridor as well. This rainfall combined with future rainfall this weekend has prompted an expansion of the flood watch in these locations. Temperatures will not change that much this evening, but then rise, especially south, as the warm front lifts north. && .SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/... Showers and embedded thunderstorms should be ongoing over much of the region Friday morning. A cold front is forecast to move into the region from the west during the day. This boundary will intersect the northeast advancing warm front. Precipitation should taper off behind cold frontal passage while continuing near the cold front and warm fronts. Additional moderate to heavy rainfall is expected. High temperatures will range from the mid 50s northwest to the lower 70s southeast. For Friday night, the cold front will slip south of the Ohio River where it will eventually stall. There should be a lull in the precipitation threat across the north, with chances continuing along and south of the Ohio River. The cold frontal boundary will begin moving back northward as a warm front late as more s/wv energy in the midlevel ripples once again into the region. Thus, have PoPs ramping up late. Lows will range from the lower 40s northwest to the upper 50s southeast. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Anomalously strong sub tropical ridge over the southeast with a moist southwesterly flow focused into the Ohio Valley to begin the long term forecast period. An active wet weather pattern to continue into Sunday leading to a continued flood threat. Mid level shortwave and deepening surface low to eject northeast from the central plains into the Great Lakes Saturday night/Sunday. Strong low level jet of 70-80 kts will provide anomalous moisture into the area and marginal instby across the area. Moisture will pool ahead of a front moving into the area late Saturday night/early Sunday with precipitable water values approaching 1.5 inches, which is a record value for this time of year. Will continue with categorical pops Saturday night. High shear low cape severe weather setup showing a signal with Sherb 0-3km parameter Saturday night. In tightening pressure gradient will have winds gust up to 35 mph. With the front expected to sweep east through the area early Sunday a drying trend to develop. Surface high pressure will build across the Great Lakes offering dry weather from Sunday into the middle of next week. Expect early highs on Sunday with temperatures falling into the 40s and lower 50s in the afternoon. Temperatures to turn cooler but still above normal with highs Monday from the upper 40s north to the mid 50s south. Temperatures Tuesday look to be around 10 degrees above normal, with highs from the lower 50s north to the upper 50s south. Model solution differences develop at mid week regarding how fast moisture returns on the backside of retreating surface high pressure. Will limit pops low chance Wednesday afternoon south and then across the entire FA Thursday. Mild temperatures to continue with highs in the 50s Wednesday and Thursday. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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IFR cigs/vsbys will be found over much of the region for the next few hours. A shot of rain will work in from the southwest before daybreak and last for a few hours. This is associated with the passage of a low level jet towards daybreak. A brief inclusion of LLWS may be necessary at CVG/LUK as it passes but the highest wind speeds will be above the 2kft threshold. Likewise, given the strong dynamics present there may be significant slant-wise convection to produce thunder. Will be monitoring both of these potentials upstream and amend if they present themselves. Rain will be an early shot and see some passing showers through the early afternoon. Focus for showers then shifts southeast and away from the TAF sites, but the proximity of the axis of good rainfall is too close to not include VCSH for the bulk of the daylight hours today. Later in the evening, models are hinting that cigs may improve if the lower thousand feet could lose its broken characteristic. A large dry area noted above 1kft would bring VFR conditions if the low stratus scatters out. CVG should see a return to IFR late in their 30 hour TAF as the next batch of rain overspreads the region in the predawn hours Saturday. OUTLOOK...MVFR/IFR ceilings and visibilities are likely into Saturday night. MVFR ceilings may linger Sunday.
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&& .ILN WATCHES/WARNINGS/ADVISORIES... OH...Flood Watch through Sunday morning for OHZ053>056-060>065- 070>074-077>082-088. KY...Flood Watch through Sunday morning for KYZ089>100. IN...Flood Watch through Sunday morning for INZ050-058-059-066- 073>075-080. && $$ SYNOPSIS...Coniglio NEAR TERM...Coniglio/Hickman SHORT TERM...Hickman LONG TERM...AR AVIATION...Franks is the U.S. government's official web portal to all federal, state and local government web resources and services.