textproduct: Omaha/Valley

KEY MESSAGES

- Heavy rain and flash flooding will be the main concern Saturday afternoon into early Sunday, though a few strong to severe storms could produce large hail and damaging winds.

- Cooler temperatures settle in Sunday into early next week, with highs mainly in the 70s and periodic chances for showers and storms.

DISCUSSION

Issued at 958 PM CDT Fri Jun 19 2026

Water vapor satellite imagery shows a longwave trough across much of the central and eastern CONUS this evening, with ridging over the West Coast. A shortwave disturbance led to the broad area of showers with a few embedded thunderstorms that moved through earlier. That is exiting to the southeast this evening. Showers and cloud cover led to temperatures not warming quite as much as expected today, with cooler temperatures expected overnight tonight. A great night to crack your windows open and get some fresh air. Winds become calm overnight with clearing skies which could lead to some patchy fog developing. Guidance suggests best potential for this is along a corridor from the Platte River north to Cuming and Burt counties east into Monona, Harrison, and Shelby counties in Iowa.

Saturday we see a more substantial upper-level wave moving into the area. This will bring a decently strong surface low into the Central Plains tracking from northwest Nebraska through northwest Missouri. As this low deepens to our west, we see increasing southerly flow lifting a warm front north out of Kansas into southeast Nebraska.

With the disturbance arriving closer to 00-03Z Saturday night, the more substantial rainfall is expected through the evening and overnight hours, but CAM guidance has been trending upward in coverage of showers and storms Saturday afternoon due to an antecedent upper-level disturbance tapping into the moist, unstable environment ahead of the main Low. Isentropic upglide will lead to a modestly unstable elevated layer north of the warm front with strong moisture advection and pooling along the elevated warm-front. With only a modest amount of shear, we're not expecting much in the way of severe weather with these afternoon storms north, but closer to the Kansas state line we do get a little more unstable. If we can get any clearing at all, low-level shear south is much better with 61kt of effective bulk shear, and 0-3km SRH of around 300. Don't think this will be a significantly large hail event, but we could see some quarters with stronger storms. Significant moisture in the environment will make large hail difficult. Instead, heavy rainfall and damaging winds will be the bigger threats from these storms.

Meanwhile, during the afternoon/evening hours on Saturday we'll see the beginnings of an MCS develop over northwest KS/southwest Nebraska. The track of this system overnight will greatly depend on where the thermal gradient sets up south of the extent of storms over eastern Nebraska. If the latest HRRR runs are true, this system will track more into northeast Kansas than southeast Nebraska, keeping the wind threat south. The greater threat overnight will be a second disturbance bringing another wave of showers and storms into eastern Nebraska, leading to additional heavy rain into Sunday morning, not clearing out until 8-10AM.

Saturday afternoon through Sunday morning we're expecting a significant amount of rainfall. HREF LPMM shows widespread amounts of 1-2 inches with locally higher amounts, generally in southeast Nebraska upwards of 8 inches in a few locations. For this reason, we have a Flood Watch issued for Saturday night into early Sunday across southeast Nebraska and far southwest Iowa.

Rest of Sunday and Beyond...

Once this system clears Sunday morning, we see quasi-zonal flow set up across the CONUS with ridging over northwest Mexico being kept south by a trough moving out of western Canada. With the polar jet more active and farther south than usual later in June, it's no surprise we'll have a cooler air mass settle in from Canada behind this Saturday system. Highs on Sunday again will only be in the low-to-mid 70s. Through the week next week we see the quasi-zonal flow transition as the ridge over NW Mexico builds northward into the Four Corners region. This will bring back more moderate northwesterly flow keeping temperature more mild despite a gradual warming trend into midweek. Shortwaves riding down the northwesterly flow out of western Canada will bring additional periodic chances for showers and storms.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/

Issued at 1249 AM CDT Sat Jun 20 2026

Expect light and somewhat variable winds overnight, though what wind there is is favored to be out of the south. Expect some fog development toward sunrise with most likely impacts at OMA, but can't rule it out at LNK and OFK. Visibility could drop below 1 mile in some spots, but kept it to 1 1/2 SM at OMA for now. Prevailing winds should then become southeasterly through the remainder of the period with some gusts of 18-20 kts at times. However, showers and storms are expected to move in by early to mid afternoon and linger through most of the period which could lead to some erratic winds along with MVFR to IFR conditions at times. There is potential for an extended period of TSRA, but for now tried to highlight the most likely timeframe at LNK and OFK, with some potential that most TS stays west of OMA.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Flood Watch from this evening through Sunday morning for NEZ065>068-078-088>093. IA...Flood Watch from this evening through Sunday morning for IAZ090-091.