Area Forecast Discussion

KEY MESSAGES

* Cool and dry weather is expected across the region today. Patchy frost will be possible over southeast Indiana and into the Bluegrass region of central Kentucky.

* Warming trend will begin on Tuesday and continue through the remainder of the week.

* A chance of showers is possible across the northern Bluegrass on Wednesday. The next weather system that will bring significant precipitation to the region will arrive late Friday and into Saturday.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 257 AM EDT Mon Apr 20 2026

Morning satellite imagery shows a band of mid-high clouds across southern Indiana and the northern half of Kentucky. Mostly clear skies were noted across southern Kentucky. The clouds are associated with a weak/dry cold front dropping thorugh the region. The cloud cover has kept temperatures up this morning with readings generally in the mid-upper 40s under the clouds. Across southern KY, the KY Mesonet shows a ridge/valley split with the protected valleys in the mid-upper 30s with lower-mid 40s on the ridges.

For the remainder of the overnight period, expect the front to slowly drop southward through Kentucky. Current thinking is that ongoing cloud cover will likely inhibit good radiational cooling, so the threat of frost appears to be looking less likely. However, there is a chance that some clearing could take place toward sunrise and we could get a quick cool down in temps that may produce some frost. For now, will keep the frost advisory intact, but if clouds linger too long, will need to yank the advisory.

For today, we'll start off with partly/mostly cloudy skies across southern IN and the northern half of Kentucky with the ongoing front dropping south. These clouds should mix out during the day leading to mostly sunny conditions. Temperatures will remain on the cool side with upper 50s over southeast Indiana and into the Bluegrass region of central Kentucky. Elsewhere, low-mid 60s are expected with upper 60s down in the Bowling Green area.

For tonight, mostly clear skies are expected. Overnight, we'll see winds veer around to the south which will keep temps a bit warmer. We'll likely see a gradient of temperature across the region. Lows will be in the upper 30s across the Bluegrass region, with lower-mid 40s in the I-65 corridor and points west.

Tuesday will feature sunny skies with warming temperatures as we get back into a return flow pattern. Highs look to warm into the 73-78 degree range with overnight lows dropping into the upper 40s/lower 50s in the valleys with mid-upper 50s on the ridges and in urban areas.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 257 AM EDT Mon Apr 20 2026

Wednesday through Thursday Night...

Upper level pattern will feature a trough in the Pacific northwest with a ridge centered in the Plains and a northwest flow over the Ohio Valley. A subtle mid-level perturbation will drop southeast during the day with a weak frontal boundary reflected at the surface. This looks to bring a chance of showers to southeastern Indiana and the Bluegrass region on Wednesday. Highs will be above normal with readings in the 75-80 degree range with overnight lows in the mid 50s. As the trough axis moves from the Pacific NW into the northern Plains, downstream ridging will move from the eastern Plains into the Ohio Valley. This will result in a dry and warm Thursday. Highs look to top out in the upper 70s and lower 80s with overnight lows mid-upper 50s to the lower 60s.

Friday through Sunday...

By late in the week, the aforementioned Plains upper trough axis will continue to deep and eventually cut off across southern Canada. A large frontal occlusion is likely to take place with a large arcing cold front extending from the western Great Lakes southward into the Mid-MO Valley. This occlusion looks to stall the front from getting here on Friday, so the forecast will be trended slightly drier, but will keep at least chance PoPs in the forecast. Highs will again be above normal with upper 70s and lower 80s expected.

The front looks to push through the region late Friday and into Saturday. PWATs look to rise above an inch here, so at least some appreciable rainfall seems reasonable. Model soundings on Saturday are not impressive in terms of deep convection. However, with the front in the vicinity, at least scattered showers seem reasonable here even into Sunday. Highs on Saturday will be a little cooler, with readings in the mid-upper 70s with similar readings on Sunday.

AVIATION /06Z TAFS THROUGH 12Z TUESDAY/

Issued at 105 AM EDT Mon Apr 20 2026

For the remainder of the overnight period, VFR conditions are expected at the terminals with light/variable winds. Weak frontal boundary will continue to shift southward with a band of high clouds passing through the terminals. Winds will shift to the northeast toward dawn and then veer to the northwest during the afternoon hours.

LMK WATCHES / WARNINGS / ADVISORIES

KY...Frost Advisory until 9 AM EDT this morning for KYZ031>033-036- 037-042-043. IN...Frost Advisory until 9 AM EDT this morning for INZ076>079-092.