textproduct: Hastings

KEY MESSAGES

- Scattered thunderstorms are expected Sunday afternoon into Sunday evening. A few storms could become strong to severe with gusts near 60 MPH and hail up to the size of golf balls.

- There is a low chance for a few thunderstorms again Monday evening. Chances for thunderstorms then increase Wednesday through Friday. Some severe storms cannot be ruled out, but widespread or significant severe weather appears unlikely at this time.

DISCUSSION

Issued at 137 PM CDT Sat May 23 2026

Diurnally-driven cumulus is bubbling over the western 2/3rds of Nebraska and down into NW Kansas. This is expected to continue to develop this afternoon and move across the area this evening as high-based showers and thunderstorms. Currently, shear is pretty lackluster, but is expected to increase into the evening hours, which will potentially allow storms to coalesce into one or more line segments. Instability falls off quickly into central Nebraska/Kansas, therefore severe weather remains unlikely. Nevertheless, these high-based showers/storms could produce some gusty winds this evening (evidenced on HRRR gust output) and perhaps some small hail in the strongest updrafts.

Sunday will trend noticably warmer than today as the upper trough moves out of the northern Plains and we see stronger southerly winds at the surface. Widespread highs in the 80s are expected, with some locations in southwest parts of the area making a run at 90 degrees. Thunderstorms are again expected to develop and move west-east across the area in the late afternoon and evening. But, unlike today, convective parameters are more favorable for a few storms to become severe. MLCAPE on the order of 1500-2000 J/kg combined with deep-layer shear of 30-35kt would support a severe hail threat, and possibly a few severe wind gusts as well. Nearly the entire area is now in a "Marginal" (level 1 of 5) severe risk area.

Overall, Monday is expected to be similar to Sunday, but the thunderstorm potential is more uncertain and likely to be more isolated. Therefore, SPC has not introduced a severe outlook.

A deep upper low is forecast to move into the western CONUS, which will eventually bring more widespread rain/thunderstorm chances to the area Wednesday-Saturday. Unfortunately, the evolution of this system is rather uncertain and therefore details on timing are hard to pin down at the moment. At this time, the overall severe risk doesn't look particularly concerning, especially for late May The GEFS CSU-MLP severe probs remain less than 5% each day through Saturday.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 109 AM CDT Sun May 24 2026

For KGRI/KEAR Airports: High confidence in VFR ceiling throughout the period and high confidence in VFR visibility through at least the vast majority of it. Except for perhaps during a brief period of passing thunderstorms Sunday afternoon-early evening, any ceiling should remain well above 5K ft. AGL.

The primary concerns of the period (in chronological order) are: - 1) Right away these first several hours (through around 13Z), modest low level wind shear (LLWS) will occur, as southwesterly winds increase to 30-35KT within the lowest 1-2 K ft. AGL. However, overall magnitude of LLWS should peak closer to 25KT than 30+KT...so it continues to be omitted from TAFs.

- 2) A 2-3 hour "window of opportunity" for thunderstorms Sunday afternoon-early evening...currently included in lower- confidence PROB30 groups 21-24Z KEAR/22-01Z KGRI. In all reality these 3-hour windows is likely plenty generous, but it can hopefully be fine-tuned as it nears. IF a thunderstorm happens to directly impact KGRI/KEAR, severe winds (58+KT) and/or hail (1+" diameter) cannot be totally ruled out. Again though, this is not considered a high probability scenario.

- 3) In the wake of the aforementioned thunderstorms, moderately-strong low level wind shear (LLWS) should develop later Sunday evening into early Monday AM (currently assigned 03-06Z), as southerly winds within the lowest 1,500 ft. AGL accelerate to at least 45KT..resulting in 30+KT of total LLWS magnitude.

Surface wind details (aside from any possible thunderstorm- related outflow): The lightest speeds of the period will be right away through around 14Z this morning (mainly under 10KT from the south). However, south-southwesterly speeds will ramp up through the late-morning and especially afternoon hours, with sustained speeds commonly 15-20KT/gusts 25-30KT. Speeds will back off slightly Sunday evening-early Monday AM, but gusts of 20-25KT will remain common.

GID WATCHES/WARNINGS/ADVISORIES

NE...None. KS...None.