textproduct: Omaha/Valley

KEY MESSAGES

- Warm conditions continue through the week, with highs mainly in the 80s, although we could see a few 90s by late week.

- A cool front on Tuesday will bring gusty northwest winds, morning sprinkles, and afternoon dry air, leading to extreme fire danger in parts of northeast Nebraska.

- Fire danger will be elevated once again on Thursday with strong southerly winds.

- There are several thunderstorm chances, focused mainly late Thursday, Saturday afternoon and evening, and perhaps again on Sunday.

DISCUSSION

Issued at 1225 PM CDT Mon May 11 2026

On Monday afternoon, surface low pressure in southern Canada was drawing warm air north, but is also bringing a cool front through eastern Montana. Closer to home, a warm front extended from near Niobrara to Nebraska City and was lifting northeast. To the west of this front, southwesterly winds were a bit gusty up to 25-30 mph, and temperatures a bit warmer. This warm southwesterly flow will overspread the entire area this afternoon with gusty winds and warm temperatures continuing through the night as the surface low moves well to our north. The air is quite dry today with RH dropping to 20% or lower, and while winds are gusty, they are just less than Red Flag criteria for today. Winds will keep tonight's low temps around 60 degrees.

On Tuesday, the cool front currently over eastern MT will push through all of eastern NE and western IA between sunrise and noon. The airmass behind the front is still quite dry, and not especially cold...particularly given ample sunshine and deep mixing. So highs will once again be in the 70s to lower 80s. The difference tomorrow is that these northwest winds will be stronger, and northeast NE into west central IA could have some gusts greater than 35 mph at times in the afternoon. This is driven by strong, deep unidirectional wind fields, dry air, and deep dry adiabatic lapse rates off the surface. Fuels are still quite dry in northeast Nebraska despite some green-up, and have thus issued a Fire Weather Watch for areas where the drier fuels and higher end wind overlap the dry RH conditions on Tuesday. Could also see a few sprinkles, particularly in the early morning hours, which may also lead to localized wind enhancements.

Wednesday will be quite pleasant, with light winds early and a breeze out of the south as the day progresses. A short wavelength upper ridge builds overhead and shifts east on Thursday while a short wave trough with negative tilt moves into eastern Montana. This will bring a strong pressure gradient and strong southerly winds probably gusting to 45 mph or so at times on Thursday. There is a small chance of an early day shower or storm to the east of an advancing warm front, but the main focus will be later in the day as the short wave trough moves out with a front/dryline. Forcing will be strong and shear profiles impressive, but boundary layer moisture will be lacking so overall instability profiles are fairly weak. Regardless, late Thursday is a period to watch for a few strong storms, but with significant uncertainty regarding convective initiation and instability.

The intensity of the frontal passage late on Thursday plays a significant role in hazardous weather potential and thunderstorm potential as we go into Friday/Saturday/Sunday. Guidance is rather variable in strength of the front in that some guidance blasts the stable post-frontal air clear through KS/MO, while others stall the front and lift it back north well into NE/IA by Friday night. Wherever the front sets up, do expect moisture pooling along it with a northerly lift over time. Substantial instability will develop near/south of the boundary with periods of rather favorable-for-severe-weather shear profiles (and other periods of less impressive wind fields). All of this to say that we'll need to be weather-aware this weekend for severe thunderstorm hazards, but it's far from a guarantee and the eventual outcome will be highly dependent on frontal positioning and timing of moisture return within the daily heating/convective cycle.

AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/

Issued at 558 PM CDT Mon May 11 2026

VFR conditions prevail at the terminals through the forecast challenge. Expect southerly winds to remain gusty through shortly before sunrise, turning to the west by 10Z at KOFK and 14Z at KOMA/KLNK. Low-level wind shear is expected to develop around 04-05Z, continuing through 10-12Z at KOFK and 13-15Z at KLNK and KOMA. A cold front will push south into the region tomorrow morning, switching winds to the northwest.

OAX WATCHES/WARNINGS/ADVISORIES

NE...Fire Weather Watch from Tuesday afternoon through Tuesday evening for NEZ011-012-016>018. IA...None.