textproduct: Omaha/Valley

KEY MESSAGES

- Dangerous heat continues Sunday, with peak heat index values of 110 to 118 degrees expected.

- Extreme heat remains possible Monday, especially across southeast Nebraska and southwest Iowa, where heat index values couch reach 110 to 115 degrees.

- A few strong storms may develop Sunday evening, mainly across northeast Nebraska, with damaging winds the primary threat. Additional storms are possible Monday evening.

DISCUSSION

Issued at 1036 PM CDT Sat Jul 25 2026

Tonight and Sunday...

Earlier this evening, an MCS tracked across southeast South Dakota, grazing extreme northeast Nebraska before gradually weakening and moving east-southeast into western Iowa. The decaying complex will leave a shield of mid- to upper-level cloud cover across much of the area overnight. We could also see some patchy fog overnight in southwest Iowa where RH values will be the highest. Temperatures and humidity exceeded most guidance today. Widespread highs reached the upper 90s to lower 100s, while dewpoints remained in the upper 70s to low 80s, higher than forecast by most guidance. This resulted in widespread heat index values of 115 to 120 degrees. Given this overperformance, the entire forecast area was upgraded to an Extreme Heat Warning this afternoon, which will remain in effect into Sunday evening.

Sunday is shaping up to be another dangerously hot day as the region remains beneath a mid- to upper-level ridge covering much of the central Plains. Lingering cloud cover is expected to diminish during the morning, allowing strong mixing into the warm air aloft. Temperatures may once again over perform guidance, with highs forecast in the upper 90s to low 100s and dewpoints remaining in the upper 70s to low 80s. Peak heat index values of 110 to 118 degrees are expected. Southerly winds will also increase during the afternoon, with gusts of 25 to 30 mph, though this will provide little relief from the extreme heat.

Another chance for storms will arrive Sunday evening near a surface trough. Strong instability will develop during the day, with MLCAPE values exceeding 2500 J/kg. However, deep-layer shear and large- scale forcing for ascent will remain modest, and CAM guidance continues to offer varying solutions regarding storm coverage and whether initiation will occur at all in the area. Should storms develop, the greatest chance will be across northeast Nebraska into western Iowa during the evening, where PoPs of 15-30% are in place. Activity would then gradually move southeastward and weaken. Damaging wind gusts will be the primary hazard, with DCAPE values of 1500-1800 J/kg supporting the potential for gusts up to 75 mph. Hail up to around 1 inch in diameter cannot be ruled out initially, though the very warm near surface air should limit hail from reaching the ground. Any lingering showers and cloud cover will shift southward into early Monday.

Monday...

Dangerous heat will continue into Monday, though confidence is lower regarding its overall extent. In addition to any lingering convective debris or cloud cover, a shortwave disturbance rounding the ridge across the northern Plains will push a cold front southward through the area. This will shift low-level winds from southerly to northeasterly and cut off moisture transport. The front will have only a limited effect on temperatures, with highs still expected in the mid 90s to low 100s, assuming residual cloud cover clears. However, it should lower dewpoints, particularly across northeast Nebraska where the frontal passage is expected before peak heating. This will produce a considerable dewpoint gradient, ranging from the upper 70s across southwest Iowa to the lower 60s across northeast Nebraska.

Peak heat index values may reach around 115 degrees across southeast Nebraska and southwest Iowa, decreasing to near 100 degrees across northeast Nebraska. Given the lower confidence in cloud cover and frontal timing, areas generally along and south of Interstate-80 remain split between a Heat Advisory and an Extreme Heat Watch with no headlines currently in place northward. A few evening storms could also develop along the front across the southern portion of the area, with a 15-30% chance currently in place. Model soundings indicate plenty of instability, yet again, with a profile supportive of strong wind gusts.

Tuesday and Beyond...

The aforementioned shortwave disturbance will weaken the ridge into the work week, with a somewhat more comfortable post-frontal air mass settling into the region. High temperatures should fall into the low to mid 90s for much of the work week, remaining slightly above seasonal norms.

Additional shortwave disturbances rounding the ridge will bring periodic precipitation chances through the period, with the greatest potential currently forecast Thursday into Friday, with PoPs of 40- 60% in place.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 526 PM CDT Sat Jul 25 2026

VFR conditions are favored through the period with generally calm southerly winds and mostly clear skies this evening. A decaying thunderstorm complex is expected to push into northeast Nebraska after 26/00Z. Confidence is low (20% chance) that this complex will reach KOFK, though patchy showers and gusty winds will be possible if the complex can hold together. Otherwise, expect increasing upper-level cloud cover overnight at FL250. After 26/18Z, southerly winds will increase to 12-15 kts and gusts up to 25 kts.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Extreme Heat Warning until 7 AM CDT Monday for NEZ011-012- 015>018-030>034-042>045. Extreme Heat Warning until 9 PM CDT Sunday for NEZ050>053- 065>068-078-088>093. Extreme Heat Watch from Sunday evening through Monday evening for NEZ052-053. Heat Advisory from 9 PM Sunday to 10 PM CDT Monday for NEZ050- 051-065>068-078-088>093. IA...Extreme Heat Warning until 7 AM CDT Monday for IAZ043. Extreme Heat Warning until 9 PM CDT Sunday for IAZ055-056-069- 079-080-090-091. Extreme Heat Watch from Sunday evening through Monday evening for IAZ055-056-069-079-080-090-091.