Area Forecast Discussion
Issued by NWS Wilmington, OH

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407 FXUS61 KILN 192047 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 347 PM EST Mon Feb 19 2018 .SYNOPSIS...
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Unseasonably warm air will continue to funnel northward into the Great Lakes and Ohio Valley through Tuesday. An unsettled weather pattern will then be in place through the upcoming weekend, allowing for multiple rounds of rain across the region.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/... A warm front will continue to lift north into the Great Lakes tonight. Unseasonably warm air on southerly winds will be place. Skies will range from mostly cloudy to partly cloudy. In a moist southwest flow aloft, the deepest moisture plume/pwats will shift to our north and west. However, it will still be skimming near our western/northwestern periphery to keep a threat of showers going there as weak embedded disturbances ripple through the southwest flow aloft. Lows will be very warm due to clouds and continued southerly/gusty winds. They will range from the upper 50s to the lower 60s. These temperatures are some 30-35 degrees above normal. Record high minimums will be broken. Please see the climate section of this AFD. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... Anomalous strong subtropical mid level ridge located off the southeast U.S. coast will keep main plume of moisture at bay to our west on Tuesday. Thus, much of the area will remain dry, except the far northwest where a shower can not be ruled out. A mix of cumulus clouds and cirrus clouds can be expected from mid morning to mid afternoon. Diurnal heating and a decent pressure gradient will result in gusty southerly winds in the upper 20s to lower 30 knots. Given the unseasonably warm air in place, along with filtered sunshine at times, highs will warm into the lower 70s northwest to near 80 southeast. Record highs look to be in jeopardy. Please see the climate section of this AFD. For Tuesday night, strong subtropical mid level ridge will become a little suppressed as mean 500 mb troughing pushes east into the Great Lakes and Ohio. This will allow deep moisture plume and associated cold front to slowly make in roads into our forecast area. As a result showers will be on the increase overnight from northwest to southeast. There may be enough instability for a rumble of thunder. Lows will range from the upper 40s northwest to the lower 60s east/south. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... The long term continues to be advertised as active with multiple rounds of precipitation and temperatures above normal for this time of year. The general idea for the long term will be a potent upper level ridge anchoring off the east coast of the United States with an upper level trough axis over the west coast. Between these two systems (or over our area) multiple rounds of precipitation will be possible. Wednesday morning a surface cold front will be approaching our northwestern zones with a line of showers and embedded thunder approaching. MUCAPE values decrease as the front heads southeast and forecast soundings on the GFS don`t look to great. Have kept the mention of thunder in though thanks to the proximity of the RRQ. During the day Wednesday the cold front will slowly sag southeast, but the precipitation will continue as low level southwest flow brings PVA across the area. At the same time the low level (850 MB) front will stall across central Ohio. The best upper level support from the RRQ will be located just off to our northwest, but still should be sufficiently close. Also at this time, PWATs are forecast to be around 1.3 to 1.4" (or near record values for this time of year). During the day Thursday, models continue to struggle on the evolution of the cold front that pushed through the area on Wednesday. Both the GFS and ECMWF have the front stalled south of the area Thursday, but the difference is in a low level shortwave that is pushing northeast around the subtropical ridge. The latest ECMWF has the wave moving across the forecast area while the GFS is more progressive. Given the forecast strength of the subtropical ridge (~595 DM) have leaned more towards the less progressive and more wet ECMWF, NAM and CMC. During the day Friday the cold front will wash out and head north as a warm front. As this happens PWATs surge back up to near 1.50". At the same time a surface low will surge northeast along the baroclinic zone. It should be noted that the deterministic runs of the GFS continue to run high compared to the ensemble mean. Still though heavy rain can be expected through this period. Late Friday into Saturday the pattern looks to finally change as the impressive ridge off the east coast begins to break down. As this happens the trough axis over the west coast will be free to progress east. This will allow for one more round of precipitation during the day Saturday. As the upper level low heads east it will open up with surface cyclogenesis occurring. The surface low will then head east and pass overhead. As of now it appears the ILN forecast area will reside close to the triple point. Sunday afternoon the low will pull east with surface high pressure and drier weather moving into the region. && .AVIATION /21Z MONDAY THROUGH SATURDAY/... A warm front will continue to lift north to the southern Great Lakes this afternoon. Widespread showers associated with the front should lift north of all terminals by mid to late afternoon. MVFR conditions should improve to VFR by this evening. Gusty winds from the south will diminish some by this evening. For tonight, warm, southerly flow will continue. There will be a slight increase in winds to bring gusts back in by 06Z. In addition, nocturnal low level jet over the top of the region will enhance, bringing the threat of non-convective LLWS around 2000 feet. Models indicate that in the low level moist flow, some MVFR ceilings may redevelop, especially for KDAY/KCMH/KLCK. On Tuesday, significant warm air advection and diurnal mixing will continue and increase southerly winds. Wind gusts by 17Z should range from the upper 20s to the lower 30s knots. Lingering MVFR ceilings at the northern terminals should lift to VFR during the morning. Precipitation in the form of showers will stay to the north and west of the terminals. OUTLOOK...MVFR/IFR ceilings and visbilities to return Tuesday night into Wednesday night. MVFR conditions possible at times Thursday through Saturday. && .CLIMATE... Record Maximum Temperatures for February 20... CVG...72 degrees...1891/2016 CMH...68 degrees...1891/2016 DAY...69 degrees...2016 Forecast Maximum Temperatures for February 20 2018... CVG...77 degrees CMH...75 degrees DAY...74 degrees Record High Minimum Temperatures for February 20... CVG...52 degrees...1994 CMH...49 degrees...1930 DAY...49 degrees...1930 Forecast Minimum Temperatures for February 20 2018... CVG...60 degrees CMH...59 degrees DAY...60 degrees && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Hickman NEAR TERM...Hickman SHORT TERM...Hickman LONG TERM...Haines AVIATION...Hickman CLIMATE...Hickman is the U.S. government's official web portal to all federal, state and local government web resources and services.