textproduct: Omaha/Valley

KEY MESSAGES

- There is 20-40% chance of storms this evening and overnight. A few could be strong to severe, with damaging winds and quarter-size hail being the main threats.

- Wet pattern continues with more storm chances this weekend into much of next week. Some storms could be severe at times, with Monday having the highest potential. Repeated rounds of storms will lead to an increasing flooding threat.

- Highs in the 70s with a few 60s this weekend, followed by 80s to low 90s Monday, and then 60s and 70s the rest of the week.

DISCUSSION

Issued at 740 PM CDT Fri Sep 11 2026

This evening we're watching a cold front moving into our area bringing potential for strong to severe storms, mainly in NE Nebraska. Looking at satellite, we've been watching storms go up in eastern SD with growing cu trailing south along the frontal boundary toward O'Neill. Cu has struggled south of Hutchinson County so far, likely due to more dry air they need to overcome farther south from the surface low. We do note cu development in Boyd and NE Holt counties, though. If any of them can get going, expect a fairly solid line of storms to light up as it moves into NE Nebraska. Still only a 20-40% chance of storms though.

If storms do develop, the environment will support a few stronger storms with potential for 50-60+ mph winds and up to quarter-size hail. As they continue southeast, though, they will only encounter more and more dry air with a strengthening warm nose aloft. What will more likely occur is if a line of storms develop, they go up around western Knox/Antelope Counties, peak just east near Norfolk to Albion before falling apart as they move through Columbus-Wisner.

Winds shift to northerly behind the front bringing in cooler air for the weekend. We'll see another shortwave trigger storms on an elevated boundary along the leading edge of the Canadian High Saturday mid-morning, continuing southeast through SE Nebraska and SW Iowa through the afternoon. Coverage of storms will greatly depend on the amount of elevated instability the environment can produce with warmer air in place in the lower levels and cooling temperatures aloft as the High moves in. If we hold onto cloud cover into Saturday, this may help to hold warmer air in the low levels increasing elevated instability, while if we clear out we may not get the needed steep lapse rates. Bulk shear (0-6km) of 45 to 55kt could support some bowing convective clusters with potential for damaging winds and large hail. With bases up around 9000 ft there is almost no tornado threat. High pressure remains in place through the rest of the evening clearing skies behind the storms.

The active pattern continues as another shortwave develops a surface low over the Texas Panhandle pushing the remnant frontal boundary (from today) back north of the kansas state line Saturday night into early Sunday. This brings showers and storms back to southeast Nebraska/southwest Iowa overnight into Sunday ahead of and along the advancing warm front. Expect Sunday to be a fairly rainy day with a transition from more stratiform rain overnight with increasing convective development Sunday morning.

We see a more substantial warm conveyor belt develop across the Plains from Oklahoma to Manitoba Sunday night into Monday ahead of a stronger upper-level trough moving across central Canada and the northern Plains. This will wrap into a developing surface tracking from eastern Colorado into south-central Nebraska on Monday. This is a good set up for enhanced low-level shear and instability, potentially bringing a fairly decent all-hazards severe weather threat Monday evening to eastern Nebraska and much of Iowa.

Going into next week, the active pattern appears likely to continue with southwesterly flow bringing a clash of southerly flow advecting moisture into the region while cooler air keeps trying to push south along a series of shortwave troughs moving through. This will continue to bring periodic chances for showers and storms with fairly seasonable temperatures.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 646 PM CDT Fri Sep 11 2026

VFR conditions this evening with winds out of the south. Winds have been gusting 25-35kt, but these are weakening going into the evening. A cold front is forecast to move through later this evening and overnight bringing a shift to northerly winds and potentially some storms. Storms have already developed along this front in South Dakota with satellite showing cloud growth along the boundary leading south toward the Nebraska state line. This increases confidence in storm potential for KOFK around 03Z this evening. Model guidance doesn't have this line of storms holding together to make it to KOMA or KLNK, but bkn cigs around 15000ft will move in ahead of the frontal boundary. Northerly winds hold overnight into Saturday with another shortwave bringing additional showers and storms to the area mid-morning into the afternoon. Confidence is low on timing and coverage of showers and storms, so have left them out of the TAFs for now. Best estimate is we see some development around 14-16Z in east- central Nebraska moving into or just south of KOFK, continuing into KLNK-KOMA around 17-18Z. Whether or not terminals see storms, northerly winds hold through Saturday with VFR conditions prevailing (outside of any storm activity).

OAX WATCHES/WARNINGS/ADVISORIES

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