textproduct: Omaha/Valley

KEY MESSAGES

- Strong to severe storms are possible tonight and again Tuesday night, with damaging wind gusts the primary hazard.

- Hot and humid conditions continue through Wednesday, with afternoon heat indices of 95 to 105 degrees.

- Widespread rain arrives Wednesday night (70-85% chance) and continue at times through Friday. Cooler weather follows, with highs in the mid 70s to mid 80s.

DISCUSSION

Issued at 117 PM CDT Mon Aug 10 2026

Tonight and Tonight...

Water vapor imagery and objective analysis this afternoon depict mid- level ridging centered over the Four Corners region and extending into the southern Plains. Along the northern periphery of the ridge, warm temperatures and near-daily thunderstorms chances will continue for the next few days as weak disturbances embedded traverse the region. High temperatures this afternoon are expected to peak in the upper 80s to lower 90s.

Thunderstorms chances return tonight as a shortwave disturbance tracks through central South Dakota towards northeast Nebraska. CAM guidance is in fairly good agreement on an MCS developing across central South Dakota this evening, followed by an east-southeastward track overnight. The primary uncertainty remains how far south this system progresses. A more northerly track would largely keep convection across South Dakota into northwest Iowa, while a farther southeastward track could bring a threat for strong to locally severe wind gusts (up to 60 mph) into far northeast Nebraska early Tuesday morning.

Additional thunderstorm development is expected across western Nebraska this evening, with convection pushing eastward during the late evening and early overnight hours. The main question will again be whether storms can remain organized long enough to reach eastern Nebraska. A strengthening low-level jet nosing into eastern Nebraska and far western Iowa overnight may provide enough support to sustain convection. As for both areas of concern, elevated instability will be sufficient, with shear likely the more limiting factor. Bulk shear values near 30 kts is generally expected across the area, with stronger values focused near and north of the NE/SD border. While an isolated pocket of hail (up to 1") can't be ruled out, damaging wind gusts will remain the primary concern for any storms that can remain sustained into the area.

Tuesday...

Any remnant cloud cover and convective debris should gradually dissipate or shift out of the area by late Tuesday morning, allowing temperatures to climb into the low to mid 90s. The warmest conditions are expected across southeast Nebraska and southwest Iowa, closer to the ridging. Continued evapotranspiration and low- level moisture transport will maintain dewpoints in the mid to upper 70s, resulting in heat index values of 100-107 degrees. The highest values are expected across southeast NE and southwest IA, where a Heat Advisory may be needed.

A spotty shower or thunderstorm cannot be ruled out Tuesday afternoon, though the better potential arrives Tuesday night into early Wednesday as another shortwave disturbance pivots across SD. CAM consistency within the 12Z guidance remains relatively low, as is often the case with weakly forced convective regimes. That said, another overnight MCS developing across central SD and tracking east- southeast towards northeast Nebraska appears plausible.

Elevated instability will again be plentiful, with bulk shear increasing to around 35 kts near the NE/SD border. Model soundings also depict relatively dry low-levels and DCAPE values near 1250 J/kg, supporting the potential for strong to severe wind gusts. As with tonight's system, the magnitude of the threat across our area will largely depend on how far south the MCS tracks into eastern NE and western IA.

Wednesday and Beyond...

Another hot and humid day is expected Wednesday, with highs in the upper 980s to low 90s. A pattern chance begins later Wednesday as a more potent shortwave disturbance ejects from the Front Range into the central Plains, helping to dampen the ridge while bringing cooler temperatures and more widespread precipitation chances to the region. Another period of strong to severe storms will again be possible on Wednesday evening.

PoPs increase Wednesday evening and peak in the 70-85% range overnight into Thursday morning. While precipitation chances decrease somewhat during the day Thursday, another shortwave disturbance is expected to bring a renewed round of 50-70% PoPs Thursday evening into early Friday. Persistent cloud cover and periods of rainfall should keep highs mainly in the mid 70s to mid 80s from Thursday into the weekend, with intermittent precipitation chances continuing through the period. The best rainfall potential exists Wednesday night into Thursday, with the NBM bringing a 40-70% probability of at least 1 inch of rainfall during this period, with the highest probabilities focused in a corridor across northeast Nebraska.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1133 AM CDT Mon Aug 10 2026

An area of fog and low-level stratus clouds over east-central is breaking up and improving late this morning. While patchy MVFR to IFR conditions are in place, primarily at KOFK, conditions are expected to improve to VFR across all terminals by 10/18-19Z. Expect generally light winds and scattered clouds at FL090 improving through the afternoon.

Widely scattered shower and thunderstorm chances move in overnight (after 11/06Z). Confidence in coverage remains low, with a 25% of showers at KOFK and 15% at KOMA and KLNK. Gusty winds (isolated up to 50 kts) and patchy MVFR conditions will be the primary hazard with any thunderstorms.

OAX WATCHES/WARNINGS/ADVISORIES

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