Onawa, IA Weather

Key Messages

- Winds gusting to around 40-45 mph this afternoon may result in isolated areas of high fire danger in northeast Nebraska, particularly across cropland areas.

- Expect another warm day today with highs in the upper 70s and low 80s.

- Shower and storm chances increase this weekend into next week (60-80%). Temperatures cool Sunday onward with highs reaching the 50s and 60s by Tuesday.

Short Term

18z RAP objective analysis depicts the H5 longwave trof over the western CONUS. Ahead of the wave, a shortwave and vort max is seen tracking toward the Panhandle/Dakotas area. Weak forcing from the feature should help increase cloud coverage this afternoon and evening. The longwave has already induced sfc cyclogenesis with the 998mb low centered over eastern Montana. As sfc high pressure remains firmly in place over the eastern CONUS, this sill places most of the Northern Plains and mid-Missouri River Valley area under a tight pressure gradient. Expect gusty southerly winds of 40 to 45 mph, particularly across northeast Nebraska while slightly lower speeds of 30 to 35 mph are expected for the remainder of the area. An H8 40 to 50 kt LLJ will overspread most of central and northeast Nebraska too, but approaching cloud cover could hamper how deep we're able to mix. Highs warm to the upper 70s to low 80s.

There is also some continued risk for fire danger over northeast Nebraska, primarily across remaining cropland areas which have had time to cure. How much we are able to dry/mix out will be dependent on the amount of cloud cover we see. Our current forecast shows minimum RH reaching the 35 to 45% range in northeast Nebraska where the strongest winds are, while the lowest RH remains over southeast Nebraska at 30 to 35%. Those working with farm equipment in cropland areas should remain aware of potential fire development and spread.

Late tonight into Saturday morning, a portion of the H5 longwave will break off and eject toward the North Dakota/Manitoba area. While the best forcing for ascent/height falls will be well north of the area, should still see some convergence along the approaching sfc front work with a stream of Gulf moisture to generate some scattered showers and perhaps a few storms, although instability will be somewhat limited at 100-200 J/kg. Have kept PoPs of 30 to 50% for northeast Nebraska from 06z to 14z Saturday.

Should see a brief reprieve from shower activity until around the noon hour as another H5 impulse approaches the forecast area from the southwest. Combined with the approaching front, should see more showers and storms develop, again across northeast Nebraska (50-70%) and lasting through the overnight hours. Highs will be a function of the frontal location, and will range from the 60s in northeast Nebraska to near 80 in our far southeast.

.LONG TERM /SUNDAY THROUGH THURSDAY/...

Sunday into Monday will see the remnants of the H5 longwave trof eject from the Four Corners area northeast toward the Central Plains. Increased mid-level forcing for ascent combined with southerly to southwesterly flow bringing in a stream of moisture should lead to more showers and storms. Northeast Nebraska looks to hit the jackpot, with 60 to 80% PoPs progged for most of Sunday and Monday. 13z NBM probabilities suggest areas along and west of a line from Columbus to Norfolk with a 50 to 70% chance at seeing an inch or more of rain by Monday evening. Probabilities for even a quarter of an inch taper off sharply with eastward extent, as Omaha and Lincoln see anywhere from a 20 to 30% chance for a quarter inch of rain.

Aviation

Issued at 1244 PM CDT Fri Oct 23 2026

VFR conditions prevail at all TAF sites for the duration of the cycle. Mid to high based cloud cover will gradually increase over the next few hours. Gusty 30 kt southerly winds remain in place this afternoon, but should decrease in speed at most sites late tonight into tomorrow morning, lingering a little longer at KOFK. Winds then turn northwesterly behind an approaching front toward the end of the TAF period. Low level wind shear overspreads terminals this evening, lasting through 13-14z. Models suggest a band of showers moving toward KOFK closer to 12z, but chances that the terminal will be impacted are less than 30%.

Oax Watches

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