103 FXUS61 KILN 092341 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 741 PM EDT Tue Oct 9 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 /THROUGH WEDNESDAY/... It has been yet another day of astounding warmth and humidity in the local area, with many locations reaching again into the mid and upper 80s with dewpoints in the mid 60s. However, today will certainly be the final day of /very/ warm temperatures, although the cooler air won't completely arrive until Thursday. This is due, in part, to buckling of the midlevel ridge east of the Ohio Valley and the eastward progression of decently deep troughing that has been centered across the central Plains for the past several days. For this afternoon, expect a decreasing trend in diurnally- driven Cu towards sunset, with a fairly tranquil overnight period to follow. Although deep-layer moisture will be on the increase towards sunrise Wednesday morning, conditions should remain dry through daybreak for the entire ILN FA. There will be one more warm night on tap -- with lows bottoming out in the mid/upper 60s amidst light winds and partly cloudy skies (with just a few patches of cirrus). && .SHORT TERM /WEDNESDAY NIGHT/... 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 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 /00Z WEDNESDAY THROUGH SUNDAY/... Skies are mostly clear across much of the area early this evening, but we could see some mid and high level clouds from time to time through the night. The combination of a few clouds and the winds staying up a bit, may help to limit the river valley fog somewhat more tonight than what we have seen the past several nights. As a result will just allow for a period of some IFR vsbys at KLUK later tonight into early Wednesday morning. Clouds will be on the increase across the region through Wednesday morning in an increasingly moist, southerly flow pattern. Models are suggesting an area of showers and perhaps a few embedded thunderstorms developing through late morning into early afternoon across Indiana and possibly pushing into far western Ohio. The western TAF sites will likely be on the eastern edge of this so will cover the threat with a tempo shra group. A cold front will approach from the west Wednesday night. Ahead of this, expect to see an increasing chance of showers with embedded thunderstorms toward the tail end of the TAF period. OUTLOOK...MVFR ceilings possible Wednesday night into Thursday. && .CLIMATE... Anomalous upper level ridge centered over the eastern conus will offer summer like temperatures. Below is a table of records for today through Wednesday 10/10. CVG Record highs and year Highest Minimum Temperature and year 10/9 90 in 1939 10/9 70 in 1982 10/10 89 in 1913 10/10 69 in 1883 DAY Record highs and year Highest Minimum Temperature and year 10/9 86 in 1939 10/9 69 in 1939 10/10 86 in 2010 10/10 66 in 1904 CMH Record highs and year Highest Minimum Temperature and year 10/9 88 in 1939 10/9 69 in 1879 10/10 87 in 2010 10/10 66 in 1879 && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...KC NEAR TERM...KC SHORT TERM...KC LONG TERM...Sites AVIATION...JGL CLIMATE...