textproduct: Omaha/Valley

KEY MESSAGES

- Warmer weather returns on today with highs in the upper 80s to low 90s. More storms are possible Monday night for northeast Nebraska (40-60% chance).

- High temperatures soar into the mid to upper 90s across southeast NE and southwest IA Tuesday before a cold front brings showers and storms (60-80% chance).

- Cooler weather arrives Wednesday and beyond, with highs in the upper 70s to mid 80s. More rain chances next weekend.

DISCUSSION

Issued at 1245 PM CDT Mon Sep 7 2026

Clearing skies this morning will pave the way for another warm day with highs mostly in the upper 80s to mid 90s this afternoon. Ridging remains in place over the Central Plains with a strong low-level jet advecting in warm-moist air. This is leading to an axis of moisture oriented up the Missouri River across eastern Nebraska and western Iowa. Subsidence from ridging aloft and strong winds will help to mix down warmer temperatures leading to a net drying effect in the sounding profile. This should inhibit shower and storm development this afternoon. We're watching the front currently in Wyoming for it to cross north into the Dakotas and drop south into NE Nebraska tonight, triggering shower and storm chances for NE Nebraska overnight into Tuesday morning. While we do have a Marginal Risk (level 1 of 5) for severe storms, it looks like the better chance for stronger storms should stay north in SE South Dakota. Even that isn't looking as good as it did in earlier runs of the CAMs. Still, that's where the better shear is found. Best window for our area is probably midnight-2am, with some potential as early as 9pm. Greatest hazards will be damaging winds and large hail.

Tuesday we'll have the frontal boundary, stalled across northeast Nebraska through the morning. Looking at the upper- level flow, the front appears to stall along the dampened ridge, flattened by a series of troughs ejecting out of Washington and British Columbia. The second trough finally kicks the crest of the ridge east, allowing the front to drop south across the rest of our area Tuesday afternoon and evening. With this, expect a line of showers and storms to develop along the I-80 corridor and shift southeast across the rest of southeast Nebraska and southwest Iowa Tuesday evening and overnight. While we will be plenty unstable, shear is limited along and ahead of the front making for only another Marginal Risk (level 1 of 5) for severe storms.

We're also monitoring the heat tomorrow along and south of the stalled frontal boundary. With moisture pooling along the frontal boundary and temperatures forecast to reach into the mid-to-upper 90s, heat indices are forecast to hit 103-107 across much of southeast Nebraska and southwest Iowa. Lower confidence right along the front from Lincoln through Omaha eastward as shower and storm development may be occurring right as we hit peak heating. This leads to a very short window of opportunity for heat indices to hit Heat Advisory criteria of 105, while areas south have a better chance. Have issued a Heat Advisory for areas with the best chance of hitting this criteria.

Showers and storms will linger across far southeast Nebraska and southwest Iowa into Wednesday morning, mostly clearing out by the afternoon. Temperatures will be milder behind the front with highs near normal for this time of year, in the upper 70s to low 80s. We stay dry and mild through Thursday as zonal flow maintains across the region aloft and a cooler Canadian high sits in place near the surface. Our next chance for showers and storms looks to be Friday when a trough brings another front through the region. The warm front lifting north in the morning will bring temperatures back up into the mid-to-upper 80s Friday afternoon with showers and storms expected to develop along and ahead of the cold front Friday afternoon and evening.

Behind this next system, expect another Canadian High to maintain seasonably mild temperatures with highs in the upper 70s to low 80s into the weekend. More rain expected Sunday into Monday with broad troughing in place aloft helping to reinforce northwesterly flow and CAA across our area.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1245 PM CDT Mon Sep 7 2026

Low clouds have cleared from KOFK this morning with mostly clear skies expected across eastern Nebraska and southwest Iowa today. Winds are out of the southeast gusting 20 to 30 kt this afternoon. These will weaken this evening as winds off the surface increase, bringing back a concern for low-level wind shear. Winds around FL017 will increase to around 45kt out of the south-southwest, while winds at the surface remain around 10-15kt out of the southeast. We do see some potential for storms to move into NE Nebraska overnight tonight, with greatest chances (40-60%) staying northwest of KOFK overnight. Best chances for showers at KOFK appear to start around 12Z (40%), with lower chances of thunderstorms (15%) until closer to 18Z.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Heat Advisory from 1 PM to 7 PM CDT Tuesday for NEZ066>068-078- 088>093. IA...Heat Advisory from 1 PM to 7 PM CDT Tuesday for IAZ079-080-090- 091.