textproduct: Omaha/Valley

KEY MESSAGES

- Hot and humid again Thursday with heat index values in the low 100s across southeast Nebraska and southwest Iowa. A Heat Advisory remains in effect through at least Friday.

- Hot and humid weather continues across the region into the weekend and into next week along with some small chances (10-30%) for nightly storms. Warm lows in the 70s will provide little relief.

DISCUSSION

Issued at 1131 PM CDT Wed Sep 2 2026

Tonight and Tomorrow:

Water vapor imagery this evening shows a compact shortwave trough ejecting NNE from Montana into Canada, with a belt of ascent overspreading Wyoming/western Nebraska into the Dakotas. A recent surface analysis shows a stationary front linking up with the surface low associated with the compact shortwave, extending from Montana through South Dakota and along the IA/MN border. We shower and storm activity has been exiting the area, pushing into northwest Iowa after developing on the nose of the low-level jet. As for any further storm or shower development, we'll be waiting through the night until westerly 700 mb winds increase convergence over eastern Nebraska and western Iowa with scattered weak showers and a rumble or two of thunder anticipated after 5 AM, lasting through much of the morning.

Aside from those rain chances, temperatures are slated to only fall into the 70s this evening, limiting the relief from the heat that has fully settled in for the next 7 days. Already, a Heat Advisory is in place for Butler to Pottawattamie Counties and points southward for heat indices that reached into the 100-107 range, and are salted to reach similar values tomorrow despite initial showers. Clearing skies by noon will allow for plenty of time for the area to heat up. Shower and storm potential heading into the overnight will be limited once again as the main forcing mechanisms remain west along the High Plains and north of the forecast area where better LLJ convergence is anticipated to occur.

Friday and Beyond:

By Friday, the shortwave mentioned above will have shed off through the flow to the east of the persistent mid/upper low parked over the Pacific Northwest, with little effect in terms of the day-to-day weather pattern. Stout ridging continues to hold over the area with most of the convective action initiating up the High Plains or along the quasi-stationary front over the Dakotas pointed southeast. We'll rely on established areas of convection to drift in from the west (carried by the weak southwesterly flow), or for storms to push into the instability gradient from the north. Regardless, ensemble members paint a bleak picture for those needing meaningful rainfall through the next 7 days.

High confidence continues to hold for heat stress across the area, with high temperatures in the 90s remaining for much of the forecast area through Tuesday underneath the continued ridging aloft. Are these temperatures the hottest we see compared to the summer months? Well not really, but the cumulative effect of highs 10-15 degrees above normal for 7 days in a row and overnight lows failing to fall below 75 degrees for areas of southeast Nebraska into Iowa spell for Major to Extreme Heat Risk. With a holiday weekend, fall sports, and other school-related activities back in full swing heading into the weekend, this last gasp of summer will catch many off- guard. As far as Heat Advisories go, this is about as late as we have ever issued one/had one take effect, further highlighting just how abnormal this is. Those waiting for a pattern break will look towards the middle of next week where the main mid/upper low translates across the northern CONUS, dragging a front through the area to knock temps back down into the 80s. From there, models are split as to the presence of another ridge building to the west, or if additional rain chances keep the heat at bay towards the end of the week.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 531 AM CDT Thu Sep 3 2026

Scattered showers and storms this morning across southeast Nebraska and southwest Iowa this morning. This continues through the morning tapering off around 16-18Z. Otherwise, the other primary concern is low-level wind shear which will diminish around 14-16Z as surface winds start to increase and winds aloft weaken. Winds will remain out of the south today gusting to 20-25kt. Skies will become mostly clear this afternoon holding overnight tonight. Low-level wind shear is expected to return starting around 03-04Z as winds aloft increase to around 45kt at FL017 out of the southwest, while surface winds remain more southerly around 10-15kt. No storms expected overnight tonight.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Heat Advisory until 7 PM CDT Friday for NEZ050>053-065>068-078- 088>093. IA...Heat Advisory until 7 PM CDT Friday for IAZ069-079-080-090-091.