textproduct: Omaha/Valley

KEY MESSAGES

- Extreme to very high fire danger is forecast for northeast Nebraska on Wednesday afternoon.

- Shower and storm chances Wednesday night into Thursday (50-80%). Some storms on Thursday afternoon and evening may be severe (15% chance for any given storm.)

- Cooler temperatures going into next weekend with more chances for showers Saturday (30%) into Sunday (80%).

DISCUSSION

Issued at 1118 PM CDT Tue Apr 21 2026

Mostly clear skies tonight with temperatures still in the mid 60s to mid 70s across eastern Nebraska and southwestern Iowa. Weather stays quiet overnight as a ridge sits across the region. Meanwhile a trough sits over the PacNW bringing our next chances for rain starting tomorrow night.

Wednesday... Winds increase out of the southwest tomorrow ahead of the approaching trough, advecting in moisture as well has keeping temperatures in the mid 80s to near 90 tomorrow afternoon. Humidity during the afternoon will stay higher, only falling into the 35 to 45 percent range across southeast Nebraska and southwest Iowa. Areas in northeast Nebraska stay drier, however, with humidity dropping to 25 to 30 percent in the afternoon. Low humidity combined with winds 20 to 25 mph gusting to 35 mph will lead to very high to extreme fire conditions across northeast Nebraska through the afternoon. A Red Flag Warning will be in effect through this period.

Overnight, we see showers and storms move in associated with the first shortwave ejecting east out of the approaching trough. This shortwave interacts with the nocturnal amplification of the Low-Level Jet developing scattered elevated thunderstorms, mainly north initially along the nose of the LLJ. As the LLJ rotates eastward overnight we see showers and storms become more widespread across eastern Nebraska and western Iowa.

Thursday... Showers and storms through the morning will help to develop a fairly strong capping inversion that will remain in place into the afternoon, despite being well into the warm-sector of the approaching cold front. Models have trended slower over the last 24 hours with the frontal passage, keeping more of our area in the warm sector through the afternoon and evening for storm development. Strong lift will need to overcome the capping inversion in place, but this seems likely to occur around 4pm- ish with initially discrete storm development along and ahead of the cold front. Once the capping inversion gets overcome, expect the line to blow up fairly quickly, with only a short window for discrete supercells. Still, very large hail, damaging winds, and tornadoes potential will start with these discrete storms. Once the line develops, we'll transition into QLCS threats, primarily wind and brief tornadoes, though hail remains possible. 0-3km bulk shear vectors are oriented out of the southwest indicating the greatest potential for tornadoes will be in northwest to southeast-oriented segments of the QLCS. This line of storms should generally be off to the east by 10pm, though possibly as late as midnight.

Friday and beyond... A cooler Canadian air mass moves in starting Friday behind the cold front, with temperatures falling into the 40s Friday morning and only warming into the mid 60s during the afternoon. as northwesterly flow persists, cooler temperatures hold through the weekend.

Over the weekend we see a strong low-pressure system pass just to our south, wrapping moisture back into the region on the north and western side of the system. Saturday we start to see this moisture move back in while the developing warm front over northeast Kansas holds back the warmer temperatures. Isentropic upglide north of this developing front, however, will provide enough lift for a few scattered showers and thunderstorms across our area starting early Saturday and continuing through Saturday evening.

Models still are figuring out the exact track of this system, with newer guidance suggesting a more northerly track. This actually puts southeast Nebraska and southwest Iowa potentially back in the warm-sector with severe storm potential on Sunday. With a more southerly track, severe weather would be unlikely. Watch this period for another chance for severe storms for at least some of our area.

Zonal flow sets up over the Central Plains early next week as ridging pushes back north out of Mexico. This will bring a more uncertain precipitation forecast though temperatures stay around or slightly below normal.

AVIATION /06Z TAFS THROUGH 06Z THURSDAY/

Issued at 1209 AM CDT Wed Apr 22 2026

VFR conditions are expected through much of the forecast period. Southerly winds increase to around 14-19kts after sunrise with gusts as high as 30kts. Winds continue to increase around late morning/early afternoon, with a few gusts up to 35kts. There is a possibility of some stratus moving into southern Nebraska around 09Z. Ceilings may lower by 12Z at KLNK/KOMA, but are expected to remain VFR at this time. Confidence in how far north the stratus deck gets is still a little low.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Red Flag Warning from noon today to 8 PM CDT this evening for NEZ011-012-015>018-030>033-042. IA...None.