textproduct: Omaha/Valley

KEY MESSAGES

- Fog development is expected tonight into Thursday morning. Patchy dense fog is possible, especially in areas that have received recent heavy rain.

- There is a low chance (15-30%) of thunderstorms across northeast Nebraska Thursday afternoon and evening. Severe weather, including large hail and damaging winds will be possible with the strongest thunderstorms.

- Temperatures fluctuate between the 70s and 80s with periodic thunderstorm chances through the remainder of the forecast period. Severe weather may continue to be possible with thunderstorms.

DISCUSSION

Issued at 1109 PM CDT Wed Aug 19 2026

A powerful MCS moved through the region earlier this afternoon. In it's wake a cooler and more stable airmass has filled in. Surface high pressure and clear skies further contribute to a quiet and quiescent night. These factors on top of recent significant rainfall should support widespread fog development across the area. Patchy dense fog may eventually develop, especially in areas that have received the most rainfall. Trends will be monitored for a potential dense fog advisory for Thursday morning. Otherwise, temperatures fall into the 60s by sunrise.

The quiet weather begins the day on Thursday, but a weak frontal boundary will nose into northeast Nebraska by mid- afternoon. This boundary and a passing disturbance may be enough to initiate a few thunderstorms. While thunderstorm coverage will be limited, any thunderstorms that form will have a potent environment to work with. Long, straight hodographs and steep mid-level lapse rates are expected to support supercells. Any supercells would be capable of producing large hail and damaging winds. Any thunderstorms are not anticipated to persist much into the evening before dissipating. Outside of any thunderstorms, most will not see any weather and can expect a quiet afternoon with high temperatures in the lower 80s.

Friday sees temperatures a touch warmer than Thursday as upper- level ridging builds to our southwest. A passing disturbance may once again result in afternoon thunderstorms across the area, but these chances are low (15-30%) at this time. The better chance for thunderstorms arrives this weekend as another cold front sags into the area. Temperatures are forecast to cool into the 70s due to increased cloud cover and periodic thunderstorm chances. Severe weather continues to be something to monitor as seasonably strong mid- to upper-level winds support thunderstorm organization. Heading into next week, the pattern changes little. A gradual ebb and flow between slightly warmer temperatures in the 80s with less clouds and thunderstorms to slightly cooler temperatures in the 70s with increased clouds and thunderstorms remains the main story. This pattern looks to further erase any long-standing rainfall deficits and further add to areas with a surplus across the region.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/

Issued at 532 AM CDT Thu Aug 20 2026

Expect visibility of 1 mile or less in fog this morning, before it dissipates toward 15Z. Then VFR conditions are favored for much/all of the period with FEW to SCT clouds around 3000-5000 ft agl. There's a 20% chance of storms in northeast Nebraska this afternoon, with OFK seeing the highest threat from 21-01Z, but guidance remains very spotty with any development and keeps storms out of OMA and LNK completely. Otherwise, winds should remain under 10 kts become southerly to southwesterly through the day.

OAX WATCHES/WARNINGS/ADVISORIES

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