textproduct: Omaha/Valley

KEY MESSAGES

- 40-70% chance for storms continues through 4 AM across northeast Nebraska. A few storms could have some large hail or strong wind gusts.

- Widely scattered showers/storms redevelop late this morning and afternoon (15-25% chance). Otherwise, hot and humid today with heat index values in the low 100s across southeast Nebraska and southwest Iowa. A Heat Advisory remains in effect this afternoon through at least Thursday evening.

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

UPDATE

Issued at 1111 PM CDT Tue Sep 1 2026

Strong to severe storms persist across portions of northeast Nebraska late this evening along a sfc boundary. While this stronger activity is finally pushing off to the north and east, more activity is seen across central Nebraska tied to an H8 LLJ. A very unstable airmass still remains in place with SPC mesoanalysis showing 3,000-4,000 J/kg of MUCAPE, particularly across areas that didn't see convection earlier this evening. Large scale forcing for ascent tied to the H5 wave appears displaced more to the north though with the strongest activity, so there is some uncertainty on how activity tied to the LLJ will behave. That said, lingering sfc to 6 km bulk shear appears strong at 30 to 40 kts, so can't entirely rule out some strong storms with large hail or gusty winds over the next few hours.

More showers and storms redevelop by Wednesday morning and could last into the afternoon hours as continued WAA persists across the area. Otherwise, forecast largely remains on track with continued threat for hot and humid conditions. The Heat Advisory remains in effect for today through Thursday evening.

DISCUSSION

Issued at 1249 PM CDT Tue Sep 1 2026

A hot and humid day is ahead of us, one of many for the foreseeable. Looking at water vapor imagery, a shortwave trough over the central Rockies is beginning to approach the region. At the surface, a quasi-stationary boundary is noted near the Nebraska and South Dakota border. The remainder of this afternoon we can expect to see mostly sunny skies as temperatures climb well into the 90s with dewpoints in the 60s and 70s. Widespread heat index values in the upper 90s and low 100s will be a concern for the area.

As the aforementioned trough moves closer to the area this evening, storms are expected to develop over portions of north- central Nebraska and south-central South Dakota. A belt of enhanced mid-level winds will result in sufficient wind shear for strong to severe storms. Large hail, damaging winds, and a low chance of a tornado will all be possible. These storms are forecast to follow along the quasi-stationary boundary towards our area late this evening. As these storms approach, a gradual evolution into a complex of storms is anticipated. These storms are expected to move across portions of northeast Nebraska after 8 PM, before exiting shortly after midnight. With the complex of storms, damaging winds is the primary hazard, but large hail and an isolated tornado remains possible. Showers and storms may linger into early Wednesday morning, but these should not pose a severe weather threat. With cloud cover over much of the area and south winds, expect temperatures to struggle to cool into the 70s.

The heat slowly worsens on Wednesday. Temperatures are forecast to climb into the mid to upper 90s across most of the area. Across east-central and southeast Nebraska, the combination of limited relief from the heat at night, and afternoon heat index values in the low 100s is leading to cumulative heat stress. A Heat Advisory has been issued for these locations as a result of this. The Heat Advisory runs into Thursday with similar temperatures to Wednesday expected. The streak of overnight low temperatures well into the 70s and high temperatures well into the 90s closes out the week. With the heat not subsiding, an extension or expansion of the Heat Advisory is possible. Outside of the heat, there will continue to be a low chance (10-30%) of showers and thunderstorms most nights, but this remains largely confined to northeast Nebraska.

The heat continues into the weekend, but eases slightly. The worst of the heat could linger into Saturday, but Sunday onward sees a slow, but steady decrease in temperatures each day. Highs back in the 80s may be something to look forward to by Monday next week. Continued nightly showers and thunderstorm chances remain during this time. Above-normal temperatures hold into next week as the large-scale weather pattern remains stagnant.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 548 AM CDT Wed Sep 2 2026

VFR conditions this morning with a few lingering weak showers and storms over northeast Nebraska. Winds aloft continue to create low-level wind shear at KOMA and KLNK. This should clear up around 15Z as winds aloft weaken and surface winds start to increase. Mostly clear skies expected today with southerly winds gusting 20-22kt this afternoon. Winds will weaken around 00Z with winds aloft picking back up around 04-05Z tonight. Expect low-level wind shear to impact all the terminals overnight tonight with scattered showers and storms redeveloping after 06Z (20-30% chance).

OAX WATCHES/WARNINGS/ADVISORIES

NE...Heat Advisory from 1 PM this afternoon to 7 PM CDT Thursday for NEZ051>053-066>068-089>093. IA...Heat Advisory from 1 PM this afternoon to 7 PM CDT Thursday for IAZ069-079-080-090-091.