textproduct: Paducah

KEY MESSAGES

- Record-breaking high temperatures and elevated humidity will bring heat index values in the 90s to low 100s on Tuesday.

- Widespread showers and thunderstorms with coverage of 70 to 100% are forecast Wednesday into Thursday morning.

- Lingering shower and thunderstorms chances with 50 to 70% coverage are forecast Thursday across northern parts of southeast Missouri, southern Illinois, and Evansville Tri- State region.

- A strong cold front will pass Thursday night, bringing a return of dry and seasonably cool autumn weather for the weekend.

DISCUSSION

Issued at 134 PM CDT Mon Oct 12 2026

As of 18z, water vapor imagery and H5 objective analysis shows an expanding mid-level ridge across the south-central and southeast CONUS, with deep troughing extending south from northwest Canada into the Four Corners region. At the surface, sprawling high pressure across the southeast CONUS is keeping conditions dry and very warm across the local area.

As the H5 ridging and southwest surface flow intensify tonight into Tuesday, tropical moisture from both the eastern Pacific (specifically Hurricane Simon) and the western Gulf/Bay of Campeche, will be advected north and east to the region. Under the ridge, 850 mb temperatures will rise to 18-20C (near or exceeding climatological values for mid-October), yielding high temperatures in the lower to middle 90s (also near or exceeding record highs).

Additionally, the infusion of tropical moisture will bring dew point temperatures into the upper 60s to lower 70s. Putting it all together, extremely anomalous heat index values in the upper 90s and low 100s are expected over the western half of the region. These heat index will also approach or exceed monthly record high values for October. While short of Heat Advisory criteria, we will be issuing a Special Weather Statement for southeast Missouri, the KY Purchase, and southwest Illinois for heat impacts on Tuesday afternoon.

Wednesday and Thursday, the H5 ridge will become suppressed slightly as a baroclinic zone develops just north and west of the area. Weak shortwaves within this flow will lead to the development of scattered to numerous showers and thunderstorms Wednesday into Thursday morning across most of the area. Moisture will pool along and south of the baroclinic zone, and PWAT values will be as high as 300-350% of normal. So while clouds and rain will keep temperatures down slightly, dew point temperatures will be near record high values for October, in the middle to upper 70s!

At this time, the potential for severe weather looks pretty minimal. Per the REFS, only a small part of the area in southeast Missouri and southwest Illinois has more than a 10% chance having SBCAPE over 500 J/kg and over 30 kts of 0-6 km shear present. However, locally heavy rainfall is possible with the elevated PWAT values. Right now, most of the area is forecast to see about 0.25 to 0.75" of rain by Thursday evening, from southeast to northwest, respectively. We may see a bit of a lull in activity Thursday afternoon as the ridge briefly expands before a deep H5 trough ushers a strong cold front through the area Thursday night into Friday morning.

Following the passage of the cold front, breezy and much cooler conditions are forecast Friday through next weekend. High pressure will build south from the northern Great Plains, bringing dry and seasonably cool temperatures for this weekend. Forecast low temperatures in the middle to upper 30s Sunday morning could even bring our first widespread frost of the season.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1159 AM CDT Mon Oct 12 2026

The TAFs are VFR. High pressure centered southeast of the region will bring steady W-SW winds around 5-10 kts under clear skies.

PAH WATCHES/WARNINGS/ADVISORIES

IL...None. MO...None. IN...None. KY...None.