Area Forecast Discussion

KEY MESSAGES

- Showers and thunderstorms are expected across the region tonight through Monday morning. Heavy rainfall will be possible across portions of western and northern Nebraska.

- With showers and thunderstorms, cannot rule out a risk for severe weather. The main threats would be strong, gusty winds with stronger thunderstorms, mainly across southwest Nebraska this evening and tomorrow afternoon.

- Expect cooler than seasonal temperatures through mid week, with daily highs mostly in the 60s. A return to more seasonal highs is expected late week.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 320 PM CDT Sat Sep 19 2026

An upper level low tracks across Wyoming today, with a trough extended to the Arizona-New Mexico border. At the surface, a low pressure system is observed over southeastern Montana this afternoon, with a cold front extended into Wyoming. This system is expected to slowly track eastward remaining just east of the main upper low, and will act as the catalyst for our rain chances over the next 24-48 hours. By this evening, expecting the cold front will track roughly into the Nebraska Panhandle. Ahead of the front, guidance continues to suggest convection developing across the Pine Ridge and expanding in a southwest to northeast oriented line. As this tracks east, expecting more widespread precipitation chances develop across western into north central Nebraska. As for severe potential, chances remain fairly limited, with the greatest potential during the early evening hours. As stratus lingered through most of the morning across western Nebraska, daytime heating has remained somewhat limited. In fact, as of 2 PM CDT, highs have only breached the lower 70s across western Nebraska, with relatively high dewpoints in the 60s. A quick examination of the KLBF sounding reveals that moisture remains abundant, especially aloft, with PWAT values exceeding 1.5 inches. However, the sounding also shows the somewhat limited instability, which mostly remains aloft. There is somewhat better deep layer shear, however, in alignment with the upper level flow ahead of the low. Guidance suggests a slight build up of higher instability values across eastern Colorado into portions of the Nebraska Panhandle this afternoon, generally aligning where the stratus deck has cleared out. With this narrow corridor of enhanced instability and supportive upper level flow, may see a few strong to severe storms fire along the boundary late afternoon into the evening across portions of eastern Colorado. Our main severe threat will be associated with these storms as they track into western and southwestern Nebraska. However, as they begin to encounter a more hostile environment, expecting that storms will struggle to maintain intensity. As these cells begin collapsing, expecting the main threat will be strong wind gusts, but cannot rule out a very brief threat for hail as well.

By late evening into the overnight hours, expecting that storms will mostly continue as rain showers across the region, though cannot rule out a few rumbles of thunder overnight. With the ample moisture available, these showers are expected to bring beneficial rainfall across most of western Nebraska, with heaviest rainfalls expected to remain west of Highway 83. In fact, with the anomalously high PWAT values, may even see some potential for heavy rainfall overnight, especially west of Highway 61. For what it is worth, the Weather Prediction Center has a SLight Risk Excessive Rainfall Outlook for areas around Pine Ridge, with a Marginal Risk remaining west of Highway 83.

With the system expected to continue to slowly track east throughout the day on Sunday, expect that showers and thunderstorms will continue across most of the region throughout the day, lasting into Monday morning. With the cold frontal passage, expect fairly cool temperatures across the region on Sunday, with highs remaining in the low to mid 60s. Again expecting abundant moisture aloft, supporting chances for beneficial rainfall across most of the region on Sunday and Sunday night. Heaviest rainfall appears most likely across northern portions of the region, remaining in closer vicinity to the upper level low. The entire region is covered by a Marginal Risk for Excessive Rainfall, with another Slight Risk remaining across portions of northwestern Nebraska. As for a severe weather risk, though portions of far southwest Nebraska are currently covered by a Marginal Risk, the risk is expected to be largely conditional on whether or not instability can develop across southwest Nebraska. With rain showers expected throughout the day and cooler than seasonal temperatures, expecting any instability that manages to develop will be very limited. However, if some greater instability can materialize, there may be a risk for strong wind gusts with the strongest cells.

Sunday night, rain showers are expected to continue across the region, with showers lasting into Monday morning, especially in northern Nebraska. A push of cooler air is also expected, with lows expected in the lower to mid 50s across most of the region. However, there is even potential for lows in the mid to upper 40s across western Nebraska into portions of the Sandhills. Potentially rainy conditions early morning Monday combined with cooler temperatures may bring a more fall-like feel to the morning commute.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 320 PM CDT Sat Sep 19 2026

As the upper level low tracks out of the region, will still see the deeper upper trough remaining across the western United States. This will help pull a cooler air mass south from Canada, keep temperatures on the cooler side to start the week. Based on current guidance, highs will struggle to get out of the 60s through at least Wednesday across most of the region. By Wednesday, may see some slightly warmer temperatures across the west, with highs pushing into the lower 70s. As mentioned, this is on the cooler side of our climatological highs across western Nebraska for late September. This is typically the week when we see average highs dropping from around 78 to 75 degrees. This will also bring cooler overnight lows, as well. In fact, Monday night into Tuesday morning, may see widespread lows in the mid to upper 40s across all of western and north central Nebraska.

Wednesday night, an upper level shortwave is expected to track north of the region, which may bring an additional chance of rain showers across the region. As this upper shortwave tracks out of the region by Thursday morning, expecting to see upper level ridging building in to close out the week. As there is a little uncertainty in the amplitude of the ridge, may still see some changes to the long range temperatures. For now, expecting a return to more seasonal highs, which again, would be around the mid 70s. However, if a stronger ridge can develop, may see highs push just a tad warmer into the upper 70s. Ensemble guidance remains in consensus that probabilities of exceeding 80 degrees remains less than a 10 percent chance to end the week, so even if we do get above seasonal, expect it would be very slightly above.

AVIATION /18Z TAFS THROUGH 18Z SUNDAY/

Issued at 1230 PM CDT Sat Sep 19 2026

Stratus is expected to remain across most of western and north central Nebraska through the TAF period, maintaining MVFR to IFR ceilings across portions of the region. Some clearing this afternoon is expected across western Nebraska, where VFR conditions may prevail, potentially extending into southwest Nebraska for a few hours. By this evening, another round of rain and thunderstorms is expected across most of the region, bringing IFR to LIFR conditions, driven by low ceilings and reduced visibility during periods of rain. These conditions are expected to last through the night into the morning and potentially early afternoon.

LBF WATCHES / WARNINGS / ADVISORIES

None.