762 FXUS61 KILN 100608 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 208 AM EDT Wed Oct 10 2018 .SYNOPSIS... Unseasonable warmth/humidity will linger one more day before a cold front brings cooler and drier conditions back to the region for the second half of the week. High pressure will build in for the end of the week into the first part of the weekend before rain chances return Sunday into Monday. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Skies are mostly clear across our area this evening. In a developing moist southwesterly flow pattern, we will likely see some mid and high level clouds at times through the night, with an overall increase possible late tonight. Overnight lows will be mainly in the low to mid 60s. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/... By Wednesday morning, seasonably strong deep-layer flow will be advecting moisture north-northeastward into the Ohio Valley. This will occur coincident with weak embedded disturbances riding northeast within the mid-layer flow, yielding a rapid increase in both cloud cover and soon to follow scattered shower/storm activity. Although there will be some instby to work with, do not expect at this juncture that thunder will be very widespread even during the afternoon hours, so kept thunder to just a chance for now. Activity will initially be focused west/southwest of the local area before a gradual increase in coverage occurs in the Tri- State area and near and west of I-75 during the early afternoon hours. Scattered showers /with a few storms possible/ will move northeast during the afternoon hours, with best coverage expected to be focused just west/northwest of the ILN FA across central/northern Indiana and northwestern Ohio. There may be a brief break in pcpn, or at the very least a lull of some sort, during the late afternoon and early evening hours before pre-frontal and frontal clusters begin to move east toward the area by 00z. With the increased cloud cover Wednesday (opposed to the past several days), temperatures will be held mainly in the upper 70s (west) to the lower 80s (east). Parts of central Ohio will have more time to warm up in the early afternoon before increased clouds/pcpn brings temps back down during the late afternoon. After 00z Thursday, scattered showers with embedded thunder will again be on the increase from the west, although this may manifest itself in multiple broken lines/clusters opposed to a cohesive convective structure. Model guidance has remained consistent showing a weakening/shearing out of the upper level energy/support as the front progresses east toward the local area during the overnight period. Although the deep-layer shear/moisture profiles will be sufficient, midlevel lapse rates, as well as overall instby profiles, will remain rather poor. This, combined with a weakening of the upper level support should yield a weakening/decreasing trend/tendency as the most widespread activity moves into east-central Indiana and west- central Ohio towards and shortly after midnight. Although lack of instby often times does not have much bearing on severe potential in these circumstances, the weakening of forcing/upper level support lends some suspicion that any severe potential should remain on the low /but non-zero/ side of things. Cannot completely rule out some gustiness translating down to the ground with the strongest cores during the first part of the overnight period, but think that this would be the exception rather than the rule given the current setup/data. Current model data suggests that the front should be approximately bisecting the ILN FA from Delaware Ohio to Owenton KY at 06z Thursday, with the front clearing the CWA by 12z. Increasing moisture from the south will allow for more cohesive rain to briefly move into parts of northeastern KY and south- central Ohio between 09-12z before steady activity pushes east with the front. Overnight lows will vary considerably from west to east Wednesday night, ranging from the upper 50s to the upper 60s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Period will begin with cold front in the vicinity of the eastern counties, along with lingering chances of thunderstorms in the east. The front will continue to push quickly to the east and precipitation chances will come to an end during the morning. Temperatures on Thursday will be non-diurnal as they steady for much of the morning in the west, while dropping in the east. By afternoon, there should be enough sunshine for a little diurnal recovery into lower 60s in the west and the mid 60s in the east. A large area of high pressure will provide dry weather Thursday night into Saturday. Temperatures will recover into the mid 50s on Friday, before dropping down into the mid to upper 30s Friday night. Will add a mention of frost to the forecast and HWO. Saturday night into Sunday an upper level s/w swings out of the southern plains. A surface low develops in response and lifts rain north across the region. Models differ on exact timing of the features, but they linger pcpn chance into Monday, before another high pressure builds in for Tuesday. && .AVIATION /06Z WEDNESDAY THROUGH SUNDAY/... Moisture will increase in low level southerly flow with mid and high level clouds increasing this morning. These clouds and some wind should inhibit the development of widespread fog this morning. Have limited any mention of fog to brief MVFR vsby restriction at KLUK early prior to the thickening clouds. Clouds will be on the increase across the region through Wednesday morning in an increasingly moist, southerly flow pattern. Models continue to suggest an area of showers thru late morning into the aftn in a region of favorable isentropic lift. Have covered this chance with a mention of VCSH. A strong cold front will push east across the TAF sites tonight. Ahead of this, expect to see an increasing chance of showers with embedded thunderstorms. Have prevailing showers with a mention of VCTS at all TAF sites but the best chance of thunder will be over the west with weakening marginal instby. After the front pushes through expect to see the development of MVFR ceilings late tonight. OUTLOOK...MVFR ceilings possible Wednesday night into Thursday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...KC NEAR TERM...JGL SHORT TERM...KC LONG TERM...Sites AVIATION...JGL