textproduct: Omaha/Valley

KEY MESSAGES

- Showers and storms overnight through Wednesday morning (60-90% chance). A few overnight could produce quarter-size hail, strong winds, and localized flash flooding.

- Milder temperatures through Thursday warming back up going into the weekend. Seasonably warm weather expected over the weekend.

- Wildfire smoke continues to drift in from the north. A small amount may be found at the surface. Most will be elevated and may produce some hazy skies.

DISCUSSION

Issued at 956 PM CDT Tue Aug 4 2026

We have a lull in storm activity this evening. Looking at the surface analysis, the cold front has stalled south of the Kansas state line as high pressure has spread across eastern Nebraska. Over the next few hours we'll see the nocturnal low- level jet ramp up triggering more showers and storms north of the surface front in a region with moderate elevated instability and 40-50 kt of shear through the cloud layer. This could lead to some more organized storm development capable of producing quarter-size hail and strong to damaging winds in addition to locally heavy rainfall. While the severe threat still seems fairly marginal, it will greatly depend on the amount of elevated instability can be generated as the LLJ advects warmer air just above the frontal boundary while the Canadian High pulls cooler air south.

Expect storms to start to redevelop around 11pm along a corridor near and just south of I-80, rapidly expanding in coverage and tracking east into Iowa overnight. Storm motions parallel to the front would support some training of storms overnight which could lead to localized flash flooding, especially over our southwest Iowa counties into Wednesday morning. Once the first round clears around 7am, CAMs show a potential second wave that will move in shortly after, bringing a more scattered chance for mostly showers at this point. The nocturnal low-level jet should be waning, decreasing any elevated instability we have left that isn't chewed through by the overnight storms. Rain chances should taper off through the afternoon.

Taking a step back and looking at the upper-level pattern, we're seeing a trough in the jet stream pull this Canadian air mass south into the Central Plains, and these storms are developing on the southern edge of this air mass. Wednesday night into Thursday we'll start to see this Canadian surface high slide eastward, bringing back southerly low-level flow while the ridge over the Desert Southwest starts to expand eastward. This will start our warming trend going into the weekend. Temperatures will still be very pleasant on Thursday with highs in the low- to-mid 80s. Temperatures will get warmer each day going into the weekend with southerly flow only strengthening ahead of a developing area of low pressure on the lee-side of the Rockies. This will amplify the low-level jet Friday into Saturday helping push temperatures back into the upper 80s to low 90s for highs over the weekend.

With a strong nocturnal low-level jet in place as well as active and diffluent northwesterly flow at the jet level, we could see a chance for nocturnal storms return Saturday night into Sunday, and again with a more substantial shortwave Sunday night into Monday. The pattern going into next week looks to hold fairly steady, characterized by a ridge over the Desert Southwest and a broad trough over the Ohio River Valley. This should keep us in the transition zone under northwesterly flow aloft, giving us seasonably warm temperatures and more chances for showers and storms through the week. This is reflected in the CPC's 6-10 day outlook by a forecast leaning warmer and wetter.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1214 AM CDT Wed Aug 5 2026

A broken line of showers and storms is observed at KLNK and KOMA early this morning. Ceilings as a result have dropped to MVFR, with IFR expected to reach terminals within the next few hours. Storms could have strong winds and heavy rain, temporarily reducing visby to MVFR. Have kept -TSRA mentions in TAFs, with transition to -SHRA thereafter. IFR ceilings linger through mid to late morning before slowly rising to MVFR/VFR thereafter. Winds remain from the north northeast throughout the period under 12 kts.

OAX WATCHES/WARNINGS/ADVISORIES

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