textproduct: Omaha/Valley

KEY MESSAGES

- Strong to severe storm chances expected for the afternoon (30%) and evening hours, with more storms possible in the late evening and overnight (70-90%).

- Continued threat for severe storms Sunday and Monday with all hazards possible.

- Temperatures cool down for Tuesday through Thursday in the 50s and 60s, warming back up toward the end of the week.

DISCUSSION

Issued at 138 PM CDT Sat May 16 2026

Satellite gives a good idea of where the upper-level warm front is located this afternoon, with partly cloudy skies along and north of the boundary from Lincoln to Plattsmouth. Skies to the south are mostly clear. We have the surface front to the south, closer to the Kansas-Nebraska state line. We're going to be watching this surface front push north into southeast Nebraska over the next few hours, with an isolated storm or two possibly developing later this afternoon. The upper-level shortwave pushes into north-central Kansas around 7pm this evening, kicking off storms in northeastern Kansas. A line of these storms will move north into southeast Nebraska around 8-9pm getting into Lincoln/Omaha around 10-11pm. This line of storms will lift into northeast Nebraska after midnight. The second round of storms develop near the Nebraska Panhandle this evening and develop into a bowing line that will push into our area around 1-2AM. Significant wind threat with this line of storms, with potential for 70+ mph winds.

Sunday will start off with lingering cooler and cloudy conditions from the overnight storms. It's going to take some time for our environment to recover, with clouds maybe not burning off until early afternoon. The developing surface low has trended farther north, deepening which will strengthen the surface pressure gradient across our area. Because of this we'll see stronger winds develop out of the south, with gusts 35 to 45 mph expected starting mid-morning through the afternoon. The first storms will develop either over northeast Nebraska or southeast South Dakota around 6pm. CAPE values of around 3500 J/kg pooling along the warm front as well as 0-6km bulk shear values of 35-40 kt should support discrete supercells initially. Later in the evening closer to 9pm the low-level jet intensifies, bringing stronger winds at 850mb into southeast Nebraska. This should light up storms all along the cold front from around Red Cloud northeast through Columbus and Thurston. 500-mb winds show steering flow pushing these storms east off the frontal boundary. the best low-level shear will be over northeast Nebraska into southeast South Dakota and northwest Iowa Sunday evening, lending to the greatest potential for embedded supercells and strong tornadoes in this area. However, there will still be enough shear for a few supercells farther south along the line of storms after 9pm for a tornado or two to develop as far south as I-80. This line of strong to severe storms clears east of our area by around 3-4am.

While the storms moved off to the east, the front does not follow, staying put across our area into Monday acting as a focus for more strong-to-severe storms on Monday. There are differences in the CAMs on where exactly the front will be Monday morning, with the HRRR keeping it just north of the Omaha-Lincoln metros. Other hi-res models have it farther south, closer to Nebraska City. It's location will greatly influence the areas with severe weather potential on Monday. Storms are expected to develop initially over north-central Kansas potentially during the early afternoon, moving into southeast Nebraska mid-afternoon into the early evening. All modes of severe weather will again be possible, with tornadoes, large hail, damaging winds, and flash flooding. These storms should clear out of our area by 10-11pm.

Tuesday and beyond we finally get a break! The front shifts south pushing the severe threat south and east of our area and bringing in a cooler Canadian air mass for mid-week next week. Tuesday will be much cooler with highs in the mid 50s to mid 60s across our area, with highs moderating back up to solidly in the mid 60s on Wednesday. Our next chances for rain hold off until later next week with temperatures warming back up toward next weekend.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 537 PM CDT Sat May 16 2026

Storms have developed in southwest Iowa and central Nebraska. Watching for this line to potentially fill in impacting KLNK, but confidence in timing is low (30%). Better chance for storms to impact KLNK and KOMA later this evening starting with a surge of development northward into these two terminals around 03-04Z. This line of storms will hang over the the terminals until a north-south line of storms moves in from the west around 06-07Z. KOFK remains north of the warm front and may not see any storms until the north-south line arrives closer to 07Z (only a 60% chance storms impact KOFK). Once the storms clear east, MVFR cigs appear likely to develop over northeast Nebraska impacting KOFK primarily. A 40% chance low stratus makes it as far south as KOMA. Clouds will be slow to clear Sunday, clearing around 17-18Z. Additional storms likely starting Sunday afternoon, but may only see an isolated storm or two until chances increase around 00Z.

Winds will remain out of the east this evening, shifting to the southeast Sunday morning, then more southerly toward the afternoon. Expect strong winds on Sunday (not generated by storms) with gusts 25-35kt. A few gusts 40kt+ possible.

OAX WATCHES/WARNINGS/ADVISORIES

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