textproduct: Paducah

KEY MESSAGES

- Another Heat Wave begins this week with daily heat index values of 100+ degrees. There is a 70-90% chance of meeting Heat Advisory criteria Tuesday-Friday. Major heat impacts are expected due to the long duration.

- Dry conditions will persist until Friday into Saturday when there is a 20-30% chance of isolated showers and thunderstorms. Rain chances will bring limited relief over next weekend.

DISCUSSION

Issued at 1220 AM CDT Sun Aug 30 2026

The heat and humidity will begin to ramp up with the start of another heat wave through all of this week as a 594 dm ridge of high pressure builds over the FA today. Despite an increase in southerly return flow, moisture advection will lag for another day as dewpoints will once again mix down into the lower 60s this afternoon. Given 850 mb WAA and deep layer mixing, nudged NBM maxTs up today into the mid 90s. By Monday, the stout ridge will be parked over the FA, with dewpoints ranging from the upper 60s to lower 70s. Due to the modest increase in moisture, temps are less likely to overachieve heading into the middle of the week. The NBM distribution is pretty tight through Thursday, falling in line with the 2m temps on the AI GFS/EC for daily highs in the mid to upper 90s. This translates to daily heat index values of 100+ degrees.

After collaborating with our WFO neighbors, have decided to hold off on issuing any heat headlines as Monday looks to be pretty borderline compared to Tuesday-Friday when the LREF supports a 70- 90% chance of needing a Heat Advisory. Unlike the previous heat wave, dewpoints really struggle to rise above 70 degrees making it difficult for heat index values to reach extreme levels. In fact, the LREF only supports a 15-30% chance of values exceeding 105 degrees as it would take maxTs trending higher into the triple digits to achieve these levels. The Heat Risk product may also be running a bit "hot" compared to the impacts that are likely as it does not factor in the previous long duration heat waves that occurred well into this summer with much higher dewpoints and similar temperatures. Overall, major heat impacts from the long duration can be expected as a Heat Advisory will be needed by early next week for what will be a much drier heat.

Limited relief begins to arrive by next weekend, but the GFS and ECMWF differ on how quickly the ridge breaks down. NBM PoPs have now increased to a 20-30% chance for isolated showers and thunderstorms on Friday and Saturday as a frontal boundary stalls south of the Great Lakes region. Some of the model ensembles suggest there is still room for rain chances to trend a bit higher, especially over northeast portions of the region. Timing is uncertain as it is contingent on how quickly the ridge breaks down.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 534 AM CDT Sun Aug 30 2026

Lingering shallow ground fog will quickly scatter out with sunrise; otherwise, VFR conditions are expected today with FEW cu around 6 kft AGL developing late morning. South winds between 7-11 kts are expected, while isolated gusts around 15-17 kts cannot be ruled out due to dry air aloft.

PAH WATCHES/WARNINGS/ADVISORIES

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