textproduct: Omaha/Valley

KEY MESSAGES

- Showers chances this afternoon, with a severe storm or two possible this afternoon and overnight across southern Nebraska and Iowa.

- Additional chances for a few strong storms return Monday and Tuesday.

- Temperatures remain cool for this time of year through much of the upcoming week.

DISCUSSION

Issued at 154 PM CDT Sat Aug 15 2026

Today and Tomorrow:

Mid/upper ridging continues to hold over the eastern half of the CONUS, with its center over the western Great Lakes while southwesterly flow in place over the western third. Drilling down to the local area, a recent surface analysis shows a complex environment, headlined by an incoming cold front to the northwest, a surface low moving to farther east into central Iowa, and another quasi-stationary front across northeastern Kansas into central Iowa. Though we are to the north of the aforementioned stationary front, a hole in the cirrus overhead is leading to increasing destabilization and warming across southeastern Nebraska amidst modest lift in the lower 300 mb of the vertical column. An area of agitated clouds near KHSI/KGRI is likely what short-term CAM guidance is hinting at, where a small swath of scattered showers and storms is forecast to develop and move eastward over the course of the afternoon/evening. Bulk shear values of near 20 kts and decreasing instability as surface moisture is mixed out will likely limit the potential of any storms that do form, but a gust to 60 mph or a quarter-size hail stone are not out of the question. The competing lift/subsidence of nearby shortwaves/MCVs will also limit the coverage of storms as well, with the most likely timing being 5 PM to 9 PM across southeast Nebraska into far southwest Iowa.

Heading into the overnight hours, another area of showers and storms will become possible as a MCV-driven cluster of scattered storms moves across northern Kansas after 2 AM. We'll be on the side of the boundary that will be more hostile to storm the cluster, but it won't take much wavering in the MCV's eventual path to graze southern Nebraska where marginally severe hail/wind are possible. To the north of those chances, fog formation is possible and currently favors northeast Nebraska into western Iowa for some patchy visibility reductions. Northwesterly winds will make it hard for widespread dense fog to settle in, but its patchy nature could surprise some motorists getting up early tomorrow morning.

For the rest of tomorrow, we'll be squarely behind of the main cold front with a refreshingly cool day with plenty of sun as highs top out in the upper 70s to low 80s. Any precipitation should stay just to the west across the western half of Nebraska, with a good breeze of 10-15 mph.

Monday and Beyond:

Monday and Tuesday see the return of strong to severe storms to the forecast, where post-frontal air is shunted back north and east and dewpoints recover back into the upper 60s to low 70s. The mid/upper pattern will have returned to modest zonal flow, helping to increase effective shear values to around 30 kts. Monday's chances still look to reside in a shortwave incoming from the northwest with activity trending into late evening/overnight hours. That boundary layer moisture only increases Tuesday ahead of the stronger cold front that will push through the area during the afternoon/evening hours. Out of the two days, Tuesday seems to have a higher ceiling based on the available convective ingredients amidst strong forcing associated with the cold front, with ML guidance suggesting as such.

Strong signals for severe weather taper off Wednesday through the rest of the forecast period as we find ourselves on the eastern fringe of the high-apmplitude ridge that develops to the west. Temperatures currently look to stay quite comfortable in the lower 80s through this period, with some minor rain chances as weak shortwaves or remnants of High Plains activity waft in from the northwest.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1240 PM CDT Sat Aug 15 2026

Pesky MVFR conditions have remained into the afternoon near and at KLNK/KOMA, with short-term models suggesting that we see ceilings improve over the next few hours. Winds are becoming northwesterly across the area, staying light into the overnight hours. Before we get to that point, a few isolated showers and storms are possible after 20z this afternoon, primarily near KOMA and KLNK while KOFK stays to the northwest of the activity. Initial signals for overnight suggest that we may get an area of fog north of KOMA reaching west to KOFK, with not enough confidence to include in the forecast at this time.

OAX WATCHES/WARNINGS/ADVISORIES

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