textproduct: Paducah

KEY MESSAGES

- Extreme heat and humidity will continue through the weekend. The Heat Advisory has been upgraded to an Extreme Heat Warning Thursday through Sunday. High temperatures in the 95-100 degree range and heat index values in the 105-112 range are expected.

- A 20-50% chance of thunderstorm is forecast this afternoon, mainly for the Evansville Tri State area, where a few severe thunderstorms with damaging winds and tornadoes will be possible. Localized heavy rainfall will also be possible. A 20-30% chance of showers and thunderstorms will continue through most of the Quad State tonight.

- Somewhat less hot and humid conditions are expected the first half of next week, as small chances of showers and thunderstorms return.

DISCUSSION

Issued at 200 PM CDT Wed Aug 12 2026

Colliding outflow boundaries over southwest Indiana will be a focus for potentially severe thunderstorms this afternoon. One outflow boundary will continue to push south through the I-64 corridor, while another one extends south southeast from Gibson county through eastern Daviess county. This boundary may be more stationary or drift slightly to the east through the afternoon. With at least moderate instability and considerable downdraft CAPE, damaging winds will be the primary severe concern this afternoon. However, a tornado threat will exist near the intersection of the two boundaries which is approaching the White River. Severe Thunderstorm Watch 577 is in effect for most of the Evansville Tri State through 8 PM.

Farther southwest, a few showers have developed over southern portions of southeast Missouri. These showers are not expected to be terribly long-lived or intense, but a few lightning strikes will be possible.

More showers and thunderstorms will be possible overnight into early Thursday morning once again mainly over the Tri State. A few stronger storms cannot be ruled out, but severe weather is not expected.

The upper level ridge will gradually build over the Quad State through Saturday and linger into Sunday before dropping back to the south for early next week. Today is the 4th day of 105 heat indices over much of southeast Missouri and adjacent portions of southern Illinois and west Kentucky, and tomorrow will be the 4th day for the rest of the Quad State. Therefore, with 105+ heat indices expected Thursday through Sunday, we have upgraded the Advisory to a Warning beginning at 11 AM Thursday and have extended it through 8 PM Sunday.

Through Sunday, temperatures are expected to trend upward through the upper 90s, as dewpoints trend a bit lower each day. So, it is possible we see some triple digit temperatures over the weekend, while heat indices may struggle to climb above 105. Regardless, this will be at least a week long extreme heat event, so the Warning will be worthwhile even if a few locations don't quite reach 105 over the weekend.

The upper ridge retreats to the south early next week, but southern portions of the Quad State could still see high temperatures in the middle 90s and heat indices may reach the triple digits again Monday. Highs will remain above normal, albeit in the lower and middle 90s through Wednesday.

Precipitation chances will come in from the north late Sunday night and especially Monday afternoon. Intermittent 15% PoPs will then linger through Tuesday and into Wednesday. Confidence in coverage and timing of precipitation early next week is very low.

AVIATION /00Z TAFS THROUGH 00Z THURSDAY/

Issued at 621 PM CDT Wed Aug 12 2026

The TAF sites seem to be clear of the afternoon convection, but did leave a Prob30 at KEVV and KOWB for a little later this evening, just in case the current convection to their west sneaks in there. Convection has had a hard time building south toward KCGI all afternoon, and figure that will continue, but will have to monitor the cluster southwest of St Louis that is currently headed that way. Otherwise, the forecasts are dry. Kept a mention of MVFR fog at KMVN.

PAH WATCHES/WARNINGS/ADVISORIES

IL...Heat Advisory until 9 PM CDT this evening for ILZ075>078- 081>094. Extreme Heat Warning from 11 AM Thursday to 8 PM CDT Sunday for ILZ075>078-080>094. Extreme Heat Warning until 9 PM CDT this evening for ILZ080. MO...Heat Advisory until 9 PM CDT this evening for MOZ076-086-087- 100-107>112-114. Extreme Heat Warning from 11 AM Thursday to 8 PM CDT Sunday for MOZ076-086-087-100-107>112-114. IN...Heat Advisory until 9 PM CDT /10 PM EDT/ this evening for INZ081-082-085>088. Extreme Heat Warning from 11 AM CDT /noon EDT/ Thursday to 8 PM CDT /9 PM EDT/ Sunday for INZ081-082-085>088. KY...Heat Advisory until 9 PM CDT this evening for KYZ001>022. Extreme Heat Warning from 11 AM Thursday to 8 PM CDT Sunday for KYZ001>022.