textproduct: Omaha/Valley

KEY MESSAGES

- Strong to severe thunderstorms are expected tonight into early Tuesday afternoon. Large hail, damaging winds, heavy rain, and an isolated tornado are potential hazards. - Cooler temperatures arrive behind a cold front on Tuesday and Wednesday. Lingering showers and thunderstorms are anticipated with a low chance of a strong to severe thunderstorms.

- A warming trend begins on Thursday with temperatures gradually increasing into the 80s. Periodic rain chances remain in the forecast.

UPDATE

Issued at 837 PM CDT Mon Aug 17 2026

A severe thunderstorm watch has been issued for portions of northeast Nebraska. A few severe thunderstorms have developed in a weak area of convergence between O'Neal and Ord. In the short-term, these thunderstorms may spread east with a large hail, damaging wind, and isolated tornado threat. These thunderstorms may struggle to persist as the environment becomes less favorable across our area. A separate severe weather hazard is anticiapted later tonight with additional thunderstorms from farther west.

DISCUSSION

Issued at 1250 AM CDT Tue Aug 18 2026

Widespread strong to severe thunderstorms have developed across western South Dakota and Nebraska. Closer to our area, a few relatively isolated severe thunderstorms have formed in a weak confluence zone over northeast Nebraska. All this activity is expected to spread east through the remainder of the evening into at least early Tuesday afternoon as multiple rounds of thunderstorms. This broad area of strong to severe weather is associated with a weak upper-level trough moving across the northern Plains and a weak cold front draped over the region. These features are helping to initiate widespread activity over a seasonably unstable airmass. In addition, stronger westerly and northwesterly upper-level winds have begun to overspread the area helping to increase effective wind shear to between 40-50 kts. The combination of all these factors is resulting in a combined threat of large hail, damaging winds, heavy rain, and perhaps a tornado or two.

Heading into Tuesday, a combination of the cold front and outflow behind late morning and early afternoon thunderstorms should limit the amount of additional thunderstorms later Tuesday afternoon. That said, areas of far southeast Nebraska nearest the cold front may see additional afternoon thunderstorms by afternoon. At least some risk of severe weather is expected with this activity. Further to the north, a cooler and more stable airmass should limit additional thunderstorm development. A few showers and thunderstorms may linger despite this. The severe weather threat with this activity will be comparatively lower. Otherwise, cooler temperatures begin to filter into the region behind the front, bringing afternoon highs in the 70s for many.

Wednesday sees temperatures in the 70s once again. Our next weather system begins to push into the northern Plains by Wednesday afternoon. Initial thunderstorms development is expected to the west of the region, but this is forecast to spread east into our area by Wednesday evening into the overnight hours. Severe weather may again be a potential hazard with this activity, but this threat is low currently.

Heading into Thursday and beyond, a gradual warming trend begins. Afternoon high temperatures return to the 80s. The broad pattern across the northern Plains does not change substantially during this time, This will result in continued periodic rain chances for the region with steady temperatures.

AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/

Issued at 1250 AM CDT Tue Aug 18 2026

Showers and storms will continue to push through the area early in the period, with another round still on in the 10-15Z window. That said, still some questions on exact timing and strength of storms at a given TAF site, though trends are toward keeping the second round southeast of OFK. Strongest storms will be capable of 40-50 kt winds out of the west/northwest and some hail along with heavy rain and MVFR to IFR visibility. Outside of storms, expect high MVFR to VFR conditions with lingering clouds around 2500 to 5000 ft agl through the afternoon. Winds will be somewhat erratic between rounds of storms, but should generally remain under 10 kts and eventually become northwesterly to northerly in the afternoon.

OAX WATCHES/WARNINGS/ADVISORIES

NE...None. IA...None.