textproduct: North Platte

KEY MESSAGES

- Strong to severe thunderstorms expected through this evening across all of western and north central Nebraska, with thunderstorms likely through the overnight hours.

- Sunday afternoon and evening brings increasing chances of strong to severe thunderstorms over central Nebraska.

- Additional rain and thunderstorms are expected Monday, with some severe potential lingering across north central Nebraska. Cooler temperatures behind the system may allow for some wintry precipitation across portions of the Sandhills Monday night into Tuesday morning, though confidence in any impacts remains low.

- Drier and warmer conditions are expected to return by the middle to latter part of next week.

SHORT TERM /THROUGH MONDAY/

Issued at 342 PM CDT Sat May 16 2026

A large upper level trough is deepening across western CONUS, promoting strong southwesterly flow aloft. Surface analysis suggests that there are two lows developing, One in south far southwest KS and another developing along the border of northeast CO and southwest NE. A distinct shortwave is starting to develop over southeast Wyoming through central Kansas. This along with some modest instability has promoted some elevated convection over the Panhandle and southwest NE. These storms have generated frequent lightning pulses where confidence remains low of precipitation reaching the ground. As such, fire starts remain a concern late this afternoon.

The main concern will be later this evening through the overnight hours. Midlevel moisture is being advected from the Gulf with dewpoints hovering in the mid to upper 50s. Ensemble guidance suggests MUCAPE will increase to around 2000 to 2500 J/kg by late afternoon with the potential of reaching 3000 J/kg, primarily in southern NE. As such, southwest NE (along and south of I- 80) has increasing confidence for the potential of very large hail where there are steep lapse rates and 0-6 km wind shear reaching 40 to 50 kts. An isolated tornado threat remains, especially if any supercells remain through the evening hours to latch on to an incoming low-level jet to elongate low-level hodographs. While there is a bit of uncertainty over the exact placement, models still suggest an intense bowing cluster developing near the warm front along southern NE mid way through this evening. Main hazards tonight will be the possibility of large hail (2"+ diameter), damaging winds (80+ mph gusts), and an isolated tornado threat.

Convection potential should wane early Sunday morning but could again return to another active severe weather day later in the afternoon. This is with the added caveat of convection being largely dependent on how far a southeast moving synoptic cold front moves through the region. Forecast models have gone back and forth over how far east convection develops in Nebraska. As it stands today, the severe environment has shifted back more westward for central and northeast Nebraska. The environment will be similar to today's environment with steep lapse rates, MUCAPE values hovering around 2000+ J/kg and 0-6 km being 40-50 kts. Main hazards will again be similar to Saturday with strong, damaging winds, large hail, and an isolated tornado threat.

LONG TERM /MONDAY NIGHT THROUGH SATURDAY/

Issued at 342 PM CDT Sat May 16 2026

Monday, the longwave trough will settle across the central Rockies into the Four Corners region. Ahead of this system, a shortwave trough will move across western Nebraska during the daytime hours. Strong 700-850mb cold air advection will spread into western and north-central Nebraska through the afternoon, leading to the development of a sharp cold front and strong baroclinic zone across the area. Behind the front, highs will remain in the 40s across north-central Nebraska, with upper 50s to lower 60s farther south. As the surface low responds and ejects northeastward, increasing lift along the boundary will support rain and thunderstorm development. Strong warm air advection east of the boundary, combined with easterly to southeasterly 850mb flow, will support elevated instability, most likely east of Highway 83. With deep layer shear of 50 to 60 knots, some storms could become organized and produce large hail. However, another possible scenario is that the cold air advection becomes strong enough to push the cold front farther south and east more quickly, keeping the better thunderstorm potential to the southeast of the forecast area. Currently, this scenario appears more likely given the tendency for fronts to move faster and farther south than model guidance has indicated so far this spring. The SPC Day 3 outlook also supports this thinking, with the greatest severe threat focused across eastern Nebraska into Kansas. Behind the system, stronger synoptic lift will persist across western Nebraska into Monday evening. While severe weather is not expected on the cool side of the system, a steadier rain may develop across the western portions of the area. Across the Panhandle and near the Nebraska/South Dakota border, temperatures may become cold enough for some snow to mix in. In addition, the proximity of the deep surface low may support strong winds across these areas. While uncertainty remains, some travel impacts could become possible due to gusty winds and potential wintry precipitation.

Tuesday into midweek, the storm system will quickly shift east of the region. In its wake, mid-level heights will begin rising across the western United States. Another weaker disturbance may move through the area Wednesday afternoon into Wednesday evening. This system appears weaker than Monday's system, and limited low-level moisture should keep precipitation coverage fairly isolated and primarily in the form of showers. Beyond midweek, upper level ridging is expected to support warmer and drier conditions through the end of the week. Highs Tuesday and Wednesday will remain on the cooler side, generally ranging from the mid 50s north to the lower to mid 60s south. A warming trend is then expected late week, with highs climbing back into the mid 60s to mid 70s before temperatures potentially return to the 80s by Friday.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1254 AM CDT Sun May 17 2026

Scattered showers and thunderstorms continue to percolate across portions of western Nebraska

Brief impacts were noted at LBF but activity should remain north of the terminal from here on out. Low-stratus should develop at both terminals and maintain largely MVFR conditions for the bulk of the forecast period. IFR conditions, potentially LIFR, are possible towards daybreak before conditions should return to MVFR. Afternoon showers should favor northern Nebraska including the VTN airspace but the cooler temperatures should limit if not prevent any threat of TS. CIGs should slowly improve towards the end of the period with a return to VFR conditions forecast.

LBF WATCHES/WARNINGS/ADVISORIES

None.