textproduct: Paducah

KEY MESSAGES

- An Extreme Heat Warning remains in effect through Saturday for a prolonged dangerous heatwave with daily heat index values ranging from 103-110 degrees. There is a 30-90% chance of triple digit heat index values continuing into Sunday over southeast Missouri, the Purchase Area of Kentucky, and adjacent portions of southern Illinois.

- Near record high temperatures in the upper 90s to around 100 degrees and near record warm overnight low temperatures in the mid to upper 70s are expected to continue through at least Saturday. These high and low temperatures are 10-15 degrees above normal, and will elevate heat impacts to an extreme level even more through the start of the holiday weekend. - An isolated shower or thunderstorm cannot be ruled out over much of the region this afternoon, and widely scattered showers and storms will be possible mainly over the Evansville Tri State and the Pennyrile region of west Kentucky Saturday afternoon. Little relief from the heat is expected, with only a 10-25% chance of rainfall exceeding a tenth of an inch where isolated showers and thunderstorms occur.

- Labor Day will be the choice day of the weekend, with highs mostly in the lower 90s, much less humidity, and a light northeast wind. The relative cool down will be short-lived, as triple digit heat indices return for much of the Quad State Tuesday through Thursday.

DISCUSSION

Issued at 255 AM CDT Fri Sep 4 2026

The Extreme Heat Warning continues unchanged through Saturday. Despite the upper ridge weakening some heading into the weekend, it remains firmly entrenched over the region and high temperatures will continue to reach the upper 90s and triple digits. In addition, dewpoints are expected to trend a degree or two higher for today and Saturday, which should keep heat indices over most of the Quad State in the 105-110 range. The increased dewpoints should allow low temperatures to hold up more into the middle and possibly upper 70s over most of the region this morning and tonight, so there will be little relief from the heat even at night.

The NBM and LREF continue to indicate that there is at least a 50% chance of triple digit heat indices over the southwestern half of the Quad State Sunday, but the chance of 105+ is 30% or less even over Carter and Ripley counties. A Heat Advisory will most likely be needed over southeast Missouri where heat indices 100-104 are expected Sunday. However, there are signs of increased convective activity Saturday afternoon and evening and a healthy northeast fetch Sunday, which cast some doubt on the thermodynamic conditions. The bottom line is that forecast confidence is not high enough to issue any heat headlines for Sunday at this time.

With the somewhat weakening upper ridge overhead and increased low-level moisture expected today, much of the most recent CAM data develops isolated convection over much of the Quad State this afternoon. At this time, it looks like southwest Indiana and the I-64 corridor in southern Illinois will remain dry, but elsewhere a brief downpour and a few stray lightning strikes will be possible. Locally gusty winds will also be possible with any thunderstorms this afternoon.

With similar thermodynamics expected Saturday, and the approach of the backdoor cold front and further weakening of the upper ridge over the Quad State, it would seem like at least scattered thunderstorms would be a good bet over much of the region. The RRFS indicates moderate to strong instability over much of the region, with 0-6km shear over 40kts over the Tri State area. It generates some fairly robust convection over the northern half of the region in the mid to late afternoon. The thunderstorms will move southeast and should dissipate by sunset. The RRFS even develops some isolated storms over the Ozark Foothills of southeast Missouri. Much of southwest Indiana is in a Marginal Risk of severe storms Saturday afternoon and evening, due to the increased shear. Damaging winds would be the primary severe concern. It certainly would not be surprising to see more coverage of thunderstorms throughout the Quad State Saturday. We will keep an eye on the forecast trends.

The preponderance of evidence supports a dry forecast for Sunday and Labor Day, with less hot conditions and a more marked decrease in humidity. Dewpoints Monday will be in the upper 50s to lower 60s over most of the region, making the holiday the choice day of the weekend.

The upper ridge pops right back over the area through the middle of next week, and as south winds bring increasing low-level moisture back north across the region beginning Tuesday, highs in the middle 90s and some triple digit heat indices will return. Wednesday may require another Heat Advisory for the entire region. There is considerable uncertainty for the end of the week in regards to the strength of the upper ridge and potential for northwest flow aloft to return to the Quad State. It is possible that we could see a cold front and decent chance of convection at some point Thursday into Friday, but given the persistence of this upper ridge it might be difficult to kill.

AVIATION /12Z TAFS THROUGH 12Z SATURDAY/

Issued at 617 AM CDT Fri Sep 4 2026

Isolated showers and thunderstorms will be possible over much of the region this afternoon. The best chance of impacting a terminal will be at KPAH. Some fog formation seems a bit more likely late tonight due to higher dewpoints expected. Added some prevailing MVFR fog at KCGI, but won't be surprised if it goes lower. KPAH could also be impacted, but confidence is too low to mention at this time.

PAH WATCHES/WARNINGS/ADVISORIES

IL...Extreme Heat Warning until 8 PM CDT Saturday for ILZ075>078- 080>094. MO...Extreme Heat Warning until 8 PM CDT Saturday for MOZ076-086- 087-100-107>112-114. IN...Extreme Heat Warning until 8 PM CDT /9 PM EDT/ Saturday for INZ081-082-085>088. KY...Extreme Heat Warning until 8 PM CDT Saturday for KYZ001>022.