textproduct: North Platte

KEY MESSAGES

- Severe weather appears likely again Sunday with an Enhanced Risk (level 3 of 5) in place for much of north central Nebraska.

- Precipitation will continue into Monday, including some thunderstorm threat in the east and cooling temperatures in the west potentially leading to a brief rain/snow mix.

- Much of next week will be on the cooler side with highs in the 60s before warming up for late week into the following weekend.

SHORT TERM /THROUGH TONIGHT/

Issued at 308 AM CDT Sun May 17 2026

The main concern in the short term will be the convection overnight and again Sunday afternoon/evening. The strengthening LLJ tonight will become the focus for additional development overnight into early Sunday morning. Storms that develop will generally be elevated in nature overnight, and although most storms should remain below severe criteria, an isolated strong to severe thunderstorm can't be ruled out with strong winds and hail being the main concern. A few of the CAMs do suggest the potential for thunderstorms lingering into the mid-morning across the northern Sandhills, however confidence is low at this time in thunderstorms continuing in the morning after sunrise.

Attention turns to Sunday afternoon and early evening. There is some uncertainty on thunderstorm coverage and severity for Sunday, as it is dependent on where the front sets up tomorrow. Current thinking is the front will be situated on the eastern portion of the forecast warning area by afternoon, generally east of HWY 83. However exactly how far east will determine how much of the area will see the potential for sfc based thunderstorm development ahead of the front, however elevated convection will be possible behind the front. The latest CAMs have trended with a quicker eastern progression of the front with the greatest threat for sfc based storm development across far north central Nebraska, generally from a line from Butte to Dunning and eastward, where the main hazards will be strong damaging winds, large hail and even an isolated tornado can't be ruled out. Although there will still be the potential to see some elevated thunderstorms west of the line, where hail will be the main concern. Will need to continue to monitor as thunderstorm development is conditional upon the frontal setup, the environment will be favorable for supercell development as MU CAPE values will range from around 1500 to 2000 J/kg across western and north central Nebraska, with greater than 2000 J/kg generally east of HWY 83 in the afternoon. 0 to 6 km shear increases in the afternoon to around 50 kts or greater. Mid level lapse rates will remain steep through the afternoon into early evening. The greatest timeframe for strong to severe thunderstorms at this time would be early afternoon progressing eastward, with most of the severe threat for convection out of the forecast area by early evening.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 308 AM CDT Sun May 17 2026

Monday...parent upper-trough will begin to depart the Great Basin and cross the Central Rockies early in the day. Strong synoptic lift will promote lee cyclogenesis over southeast Colorado. This will draw a strong cold front south into western Kansas and promote cold air advection across much of western Nebraska. Daytime temperatures continue to fall with consecutive forecasts with highs only reaching the lower 40s to middle 50s now. Though squarely on the cooler side of the advancing cold front, steep lapse rates remain in place across portions of central Nebraska and this will promote elevated instability within a strongly sheared environment. This fails to close the door on any threat for a strong/severe thunderstorm in our eastern zones but does limit the threat considerably. The latest SPC Outlook keeps only general thunder in the area with a sharp gradient of Marginal to Slight to Enhanced Risk levels not far to the east. The NAM12 solution depicts rapid thunderstorm development within northerly flow of northeast Nebraska, not far from Garfield/Wheeler/Holt Counties. Folks should continue to monitor the forecast for the latest details regarding any thunderstorm threat late in the day. Further west across the Sandhills into the Panhandle, more persistent precipitation is likely to occur due to strong synoptics in the area, notable the previously mentioned height falls, increasing divergence aloft, and DCVA will lead to a broad shield of light to moderate precipitation. Temperatures at h85 will fall to around 0C with lows falling into the upper 20s to lower 30s. This will support some potential for a brief transition to snow. The duration of this should remain short enough to preclude greater impacts though. This is supported by < 10% potential for seeing measureable snow in the local area. Even so, late May snow is fairly uncommon and folks should continue to monitor the forecast, should this outlook remain consistent, for potential minor impacts.

Tuesday and beyond...trough axis will clear the region by late Monday with mid-level heights expected to build in fairly quick. Relative zonal flow will become established by midweek with low amplitude ridging upstream eventually supporting quasi-northwest flow. High pressure will work in towards Wednesday and will maintain cooler temperatures. Southerly flow on the backside of this feature will draw in some moisture and set the stage for some light precipitation potential. The late week setup will be fairly active with recurring Chance PoPs (up to 35%) for Thursday through the weekend. While PoPs suggest reasonable rain potential, moisture will likely be stymied by a surface front impeding some northerly moisture advection. This suggests light rain events, not any particularly wetting event, with lack of any real moisture source. Temperatures will moderate some, with a return to seasonable levels by Friday and slightly above normal temperatures by the following weekend.

AVIATION /12Z TAFS THROUGH 12Z MONDAY/

Issued at 640 AM CDT Sun May 17 2026

Degraded aviation operations are likely through much of the forecast period at area terminals due to expansive low stratus and the threat for rain/thunderstorms.

For LBF: Low stratus will likely persist with potential for further degradations including possible IFR/LIFR CIGs over the next few hours. A period of light showers appears possible around midday with breaks likely by mid-afternoon when VFR conditions may return. Late tonight, thunderstorms will approach from the southwest but most NWP guidance weakens activity before arriving into the airspace so confidence in the magnitude of impacts is low.

For VTN: ongoing showers and weak thunderstorms to the west of the terminal should remain largely to the west. Will carry a VCSH mention though as activity is moving southwest to northeast. Will add a prevailing -TSRA mention for the late morning and afternoon hours as HRRR guidance hints as fairly persistent isolated to widely scattered showers/t-storms in the area through the day and timing of breaks is low confidence. Dry conditions should return tonight and persist through the end of the period.

LBF WATCHES/WARNINGS/ADVISORIES

None.