textproduct: Omaha/Valley

KEY MESSAGES

- A Heat Advisory remains in effect for the entire area until 10 PM. Expect afternoon heat index values of 105 to 110 with overnight heat indices remaining in the 70s.

- A few strong to severe storms will be possible this afternoon and evening (20-40% chance). Damaging winds will be the primary threat.

- Cooler weather returns by the middle of the week, with high temperatures falling back into the 80s and even some 70s Thursday. There will be increasing chances for showers and storms Wednesday through Friday.

- Warm weather looks to return by the weekend.

DISCUSSION

Issued at 1227 PM CDT Mon Jul 20 2026

Today and Tonight...

Excessively hot temperatures simmered over the forecast area this afternoon as a high pressure system dominated the western half of the CONUS. By noon, temperatures had reached the low 90s with dewpoints spanning the 70s. Heat indices ranged from 99 to 105.

But relief is in sight! Surface analysis indicates a cold front currently draped from north central Nebraska to southern Minnesota, associated with a midlevel low moving into the Great Lakes, will move southeast across eastern Nebraska and western Iowa this afternoon and evening. Instability will pool ahead of the boundary, setting the stage for deep moist convective updrafts to develop. However sustained strong storms may be limited by strongest shear vectors lingering just behind the front. While storms likely won't survive long enough to produce large hail, they could fall down in a hurry, creating the potential for strong, damaging wind gusts. This can be verified by noting the 1400-1600 J/kg of DCAPE building over northeast Nebraska.

In addition to thunderstorms, northerly winds behind the front could bring down some near-surface smoke from Canadian wild fires. While it's not expected to be nearly as impactful as it was near the Great Lakes recently, it may be noticeable, especially across the northern half of the CWA.

CAMs hint at another line of elevated showers and storms developing behind the surface front late tonight and into early Tuesday morning, as the LLJ ramps up. However these storms are even less likely to become strong or severe, as the front scours out remaining instability with it's passage.

Tuesday through Friday...

Storm coverage will gradually dissipate through the morning, Tuesday, as the line moves south. Temperatures will finally take it down a notch, behind the passing front Tuesday afternoon. Highs are expected to be within a few degrees of "normal", reaching the mid and upper 80s by the afternoon.

A much more noticeable change in temperatures arrives Wednesday and continues through Friday. Highs will generally reach the upper 70s and lower 80s Wednesday and Friday, with a few locations only topping out in the mid to upper 70s Thursday!

A pair of quick-hitting shortwaves will aide in the push of cooler air Tuesday night/Wednesday and Thursday/Friday morning. Not only will these bring cooler temperatures, but also some much needed wetting rains with showers and thunderstorms. WPC highlights southeast Nebraska and southwest Iowa with a Slight Risk for excessive rainfall Thursday, where deep moisture and training storms may be possible.

Saturday and Beyond...

Unfortunately, longer range models continue to hint at the potential for the ridge to rebound this weekend and into next week, bringing a resurgence of heat. A few shortwaves rippling around the ridge could bring some mild relief with cloud cover and low precip chances. But overall, CPC outlooks maintain above normal temperatures are likely to stick around through at least early August.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1227 PM CDT Mon Jul 20 2026

Primarily VFR conditions are expected to prevail through the period. A cold front will move through this afternoon and evening, bringing southwesterly winds around to the north. A few showers and storms are expected to develop near the front. Some could be strong to severe, capable of producing damaging winds. The best chance for storms near KOFK will be between 21-00Z, and near KOMA between 00-06Z. Chances are low (10-20%) that these storms will make it to KLNK. Another round of non-severe storms could develop around all 3 sites between 08-12Z Tuesday morning. However, uncertainty remains as to where exactly storms will develop and if they will actually impact any of the TAF sites. The frontal passage could also blow some wildfire smoke into the region this evening and Tuesday, temporarily reducing visibilities to as low as 6SM at times.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Heat Advisory until 10 PM CDT this evening for NEZ011-012- 015>018-030>034-042>045-050>053-065>068-078-088>093. IA...Heat Advisory until 10 PM CDT this evening for IAZ043-055-056- 069-079-080-090-091.