567 FXUS61 KILN 141040 AFDILN Area Forecast Discussion National Weather Service Wilmington OH 640 AM EDT Mon Apr 14 2025 .SYNOPSIS... A cold front will sweep east across the area this afternoon offering a chance of showers and thunderstorms. A secondary trough of low pressure will move through on Tuesday leading to a continued chance for showers. High pressure building in at midweek will provide dry weather. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Strong 80-90 kt mid level jet will move across the Central Plains toward the Ohio Valley as a positively tilted trof moves southeast across the Upper MS Valley today. This will result in height falls and favorable lift with exit region of the jet overspreading the Ohio Valley. Surface cold front to push southeastward through the region this afternoon. Ahead of this front, low-level moisture will advect northeastward with a ribbon of dewpoints in the upper 50s into the area. The degree of instability remains somewhat uncertain. A number of the CAM solutions develop moderate instability with mixed layer CAPE values approaching 1500 J/KG by 21Z into northern KY and south Central Ohio. This will support the development of deep convection with scattered thunderstorms developing ahead of the front this afternoon. Bulk shear (0-6km layer) looks to be between 55-60 kts which will support organized convection and a severe threat. A severe weather threat exists - generally southeast of I-71, with a time frame between 3 pm and 8 pm. Damaging winds and large hail are the main threats. In addition - supercells and a tornadic threat will exist. The best chance for tornadoes in ILN/s area is over northeast KY and South Central Ohio. Have continued to highlight this severe threat in the HWO and briefing products. High temperatures to range from the upper 60s northwest (where the front moves thru by mid afternoon) to the mid 70s southeast. Southwest winds 10 to 15 mph will gust to 25 to 30 mph before shifting to the west with the frontal passage. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Mid and upper level low centered north of the Great Lakes with a digging shortwave rotating southeast across the area overnight into Tuesday. At the surface - the cold front will clear the area by evening with a decrease in clouds until later in the night with the approach of the shortwave. Winds will be persistent through the night from the west at 10-15 mph gusting up to 25 mph at times. Temperatures drop to lows from the lower 40s northwest to the mid/upper 40s southeast. Mid level trof to sweep through the region on Tuesday. Cyclonic flow, CAA and moisture off the Great Lakes will keep skies mostly cloudy throughout the day. Scattered showers will likely develop during the daytime hours, with the best coverage over the northeast. High temperatures to range from the upper 40s to the lower/middle 50s. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... In the post-frontal atmosphere, increasing heights will be found through Friday night when an upper ridge axis rests over the region. The axis then flattens out until another ridge builds in on Sunday. In the evening, the ridge moves east and falling heights occur until a degrading s/w trough apex skims ne through srn LMich, with zonal sw flow following afterward. For the sensible weather occurring underneath this steering flow, a n-s surface ridge builds to the west on Wednesday, crosses the CWA overnight and is exiting eastern CWA by daybreak Thursday. Return flow sets up and an elevated warm front passes to the northeast overnight. Surface flow turns southwest during the day and increases, bringing in warmer air from the south. Upper level energy lifts northeast with the flattening/exiting upper ridge and sparks shower activity to the north. This activity is being wrung out along a cold front stretching sw from the parent low in WI. The parent low moves ne and a cold front passes south through the CWA on Saturday, along with showers and thunderstorms. As the parent low moves further ne, the trailing cold front stretches/thins into a stationary front oriented w-e somewhere along the Ohio River. Strong high pressure in the Great Lakes region crosses east overnight, builds east of the region and dissipates the surface front from e-w, and dissipates any ongoing convection during the evening. The next surface low in the Plains ejects ne into the Upper Midwest Sunday night, with a high probability of a cold front and convection moving e through the CWA on Monday. Temperatures will start in the mid-upper 50s Wednesday, warm to the mid 60s Thurs and top out in the mid 70s in the warm sector Friday. Sat and Sun will moderate with the stalled front to range from the mid 60s north to mid 70s south. Warm air then wins out with highs on Monday from 70 in the west to near 80 in the east. Lows will follow a similar trend, starting mid-upper 30s Tue and Wed nights and warm to the upper 50s Fri night. Sat night will fall to 40-50 n-s and moderate to the 50s Sun night. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... A low level jet will offer WAA and a scattered to broken mid level deck of clouds as a warm front lifts north thru the Ohio Valley this morning. Instability develops this afternoon ahead of the cold front with scattered showers and thunderstorms this afternoon. The best chance for pcpn will be mainly along and southeast of I-71, and will cover this with a prob30 group for a few hours at all of the TAF sites except KDAY. Pcpn chances taper off through late afternoon as the front moves through the area. Expect VFR conditions this evening with lower clouds developing into the northern TAF sites late. Have kept these clouds VFR but MVFR ceilings will be possible. A period of LLWS will be possible this morning as the low level jet overspreads the region. Ahead of the front, surface winds will become southwest through the day with gusts of 20 to 25 knots possible. The winds will shift to the west-northwest with the passage of the front. OUTLOOK...No significant weather expected. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...AR NEAR TERM...AR SHORT TERM...AR LONG TERM...Franks AVIATION...AR