SHORT TERM /THROUGH SATURDAY/
Issued at 342 PM EDT Fri Jul 26 2024

Sfc front is currently very near the Kentucky/Tennessee border, and starting to show signs of wavering back to the north as a warm front, especially out toward western Kentucky. Sfc high pressure over Lake Huron is funneling a drying NE wind which has pushed upper 50s/lower 60s dewpoints into southern Indiana and north-central Kentucky, but moisture pooling near the front has kept dewpoints in the lower 70s in south central Kentucky. The front and increased moisture, coinciding with a saddle point in the upper ridge, will support a few isolated/scattered showers or thunderstorms during the next few hrs over south central Kentucky. Weak wind fields will not allow any storms to move anywhere fast, but with PWATs barely at 1.5 inches even the flooding threat is limited today.

Convection will die out an hour or two after sunset, with some breaks in the cirrus ceilings overnight. Light winds and decreasing cloud cover will support decent radiational cooling, but not ideal, so mins will be generally in the 60s.

By Saturday the upper ridge starts to retreat toward eastern Kentucky, with a weak southerly component through a deep layer. Best moisture feed will run up the Mississippi Valley, so POPs will increase from the south and west. Look for a 20-30 percent chance focused mainly SW of Interstate 165 and south of the Cumberland Parkway. Storms on Sat afternoon will again be slow movers, with a bit more heavy rain potential as PWATs creep up toward 2 inches. No severe threat otherwise given the lacking wind fields.

LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/
Issued at 342 PM EDT Fri Jul 26 2024

Heading into Saturday night and Sunday, the relatively narrow upper ridge over the Ohio Valley will begin to get pushed out of the way by a strong shortwave associated with an upper trough, and while this is going on, moisture at all levels will be flowing northward across the CWA Precipitable water values will climb to above 2" all the way up into the Great Lakes region, and when PWATs get over 2" in our region, it's time to dig a little deeper into the data due to heavy rainfall and flooding concerns.

Model soundings show deep layer saturation and "long skinny" CAPE.
Deep layer (0-6 km) shear is fairly weak around 25 knots where it has remained for most of this past week. Storm motion looks to be around 15 knots, and with temperatures expected to be in the 80s which should make for a deep warm layer. All of this supports a risk of showers and thunderstorms that could produce heavy rainfall and localized flooding, so in coordination with WPC and surrounding forecast offices, WPC is placing most of the CWA in the Slight risk area of their Excessive Rainfall Outlook for Sunday.

Looking past Sunday, an upper high parks over Texas and will stretch over most of the southern US, setting up an ugly northwest flow type pattern from the Northern Plains into the Lower Ohio Valley.
Multiple shortwaves will work towards the CWA along this flow. Some of these waves will push their own moisture which will meet up with moisture already over the CWA, causing precipitable water values over the CWA to bounce between 1.5" to just over 2" through the end of the workweek. Nothing looks severe as the typical summer time shear remains weak, but isolated to scattered showers and thunderstorms will continue. High temperatures are expected to increase a little each day until reaching into the low to mid 90s on Thursday.

Beyond Thursday, the GFS has a cold front moving through on Friday, but the Euro parks a surface low nearby, continuing rain chances.
So, confidence remains low for the late week period.

AVIATION /12Z TAFS THROUGH 18Z SATURDAY/
Issued at 1255 PM EDT Fri Jul 26 2024

Mid/high ceilings and light NE winds will be the overall theme this afternoon, though moisture pooling over south central Kentucky could support isolated-scattered convection late. Will include a PROB30 for TS in BWG focused on the 21Z-00Z time frame.

Winds go light/variable with sct-bkn cirrus ceilings overnight. BWG could see some MVFR fog, which we may need to be more aggressive with if they get substantial rain this afternoon/evening. Otherwise will keep it VFR. Winds take on more of an easterly component Saturday morning, but speeds remain aob 5 kt.

LMK WATCHES/WARNINGS/ADVISORIES
KY...None.
IN...None.