textproduct: North Platte

KEY MESSAGES

- A cool, raw day is in store for western Nebraska Monday as daytime highs remain 20-30F below normal and light rain crosses the area.

- Cooler overnight lows Monday and Tuesday night may lead to the potential for at least patchy frost/freeze conditions west of Highway 83.

- Periodic light precipitation potential will persist through the upcoming week as daytime highs climb to seasonable and then above normal values by the late weekend.

SHORT TERM /THROUGH TUESDAY NIGHT/

Issued at 206 AM CDT Mon May 18 2026

Early this morning, scattered showers were lifting north and east across the Sandhills and portions of the Nebraska Panhandle. This was associated with a weak impulse located around h7 ejecting ahead of the parent trough situated across the Great Basin. Light rain is possible beneath this activity as low level humidity remains fairly high within a post frontal airmass. Temperatures largely sit in the upper 40s to lower 50s with breezy north winds. Cloud cover should keep temperatures from falling too significantly though morning lows will still reach 5-10F below normal for late May.

Monday/Monday Night...northerly low-level flow will persist through the daytime across western Nebraska. The frontal inversion will support cloudy to mostly cloudy conditions for the bulk of the daytime and combined with persistent cold air advection, should keep temperatures in check across the region. Afternoon highs will likely only reach the lower 40s in the northwest to near 50F in our far south and east. These values will approach 30F below normal for mid- May and when factoring in steady north winds gusting 20 to 30 mph, feels like temperatures will struggle to climb out of the lower 30s for portions of the area. Main upper trough will begin to pivot by midday as it crosses the central Rockies to the west. This will lead to a fairly expansive area of thunderstorms along a stalled frontal boundary and associated baroclinic zone draped in southeast Nebraska. It is here where the Storm Prediction Center has maintained a Moderate Risk (Level 4 of 5) extending south into Kansas and folks with interests in these locations should check for local information regarding this threat from reliable sources. Further west in the local area, the cooler temperatures will all be prevent the threat for severe weather. While MUCAPE may approach 500 j/kg, perhaps enough for a rumble of thunder across central Nebraska, severe weather is not anticipated west or north of the Tri- Cities. Lift via increasing height falls, cyclonic vorticity advection, and frontal forcing should lead to expanding precipitation primarily for the Panhandle into portions of north central Nebraska. PoPs should gradually increase this afternoon with the highest probabilities arriving by early evening. Even with the cooler temperatures, precipitation is expected to fall as rain with colder air waiting to filter in until precipitation has departed. Rates should be slow and steady given primarily synoptic lift and limited if any instability. The result is showery activity overtop the widespread stratus. HREF probability matched mean (PMM) output suggests most locations see < 0.10" outside the Panhandle and our far northern counties. The going forecast matches this well with most locations seeing < 0.05" save for the Pine Ridge vicinity where closer to 0.20" seems plausible. Precipitation exits the area shortly after Midnight tonight with temperatures then falling to the upper 20s in the west to middle 30s east. The going forecast lows of 32F and 33F at North Platte and Valentine respectively fall into the lowest 10% of observed values for the May 19 date. Will defer to later forecasts for potential Frost/Freeze headlines but believe these will be necessary given recent updates of susceptible vegetation.

Tuesday/Tuesday Night...behind departing trough, mid-level heights will begin to build quickly across the region. Surface high pressure will nose in from the west and support steady northwesterly winds. Increasing h85 temperatures and downsloping flow should produce a warmer day as temperatures look to return to the upper 50s to lower 60s. Subsidence aloft will allow for eroding clouds and dry conditions. High pressure will settle to the east and return southerly flow should become established by late evening. Cloud cover should increase as a result with subtle moisture advection over the High Plains. Forecast lows remain on par with Monday night's forecast values so additional Frost headlines may need to be considered if the current forecast holds.

LONG TERM /WEDNESDAY THROUGH SUNDAY/

Issued at 206 AM CDT Mon May 18 2026

The extended pattern will generally favor warming temperatures with periodic rain and thunderstorm potential. Southwesterly flow should return by mid week as modest troughing forms west of the Continental Divide. Moisture should increase across the area and set the stage for low-end PoPs periodically. Temperatures should moderate steadily with NBM median MaxT and MinT values showing 4-6F day-over-day climbs. Given the expected daytime temperatures returning to seasonable and then abnormally warm values, believe any precipitation potential will likely come in the form of thunderstorms. Generally weak mid-level flow will likely limit the threat for any widespread severe weather event at this time. An approaching trough on Friday may pose the greatest potential for western Nebraska as a cool front moves out of the Northern Plains. NBM matches this timeframe with 10-20% potential for seeing > 0.25" precipitation but greater probabilities are apparent east of the local area. Beyond Friday, drier conditions appear likely as precipitable water values fall off and upper-level ridging builds across the Western CONUS. NBM probabilities for exceeding 90F climbs by late weekend, with probabilities reaching 20-40% by Sunday and 40- 70% by Monday. Higher percentile outputs suggest mid to upper 90s for these days, but inner-quartile spreads remain reasonably large so certainty is low at this time.

AVIATION /18Z TAFS THROUGH 18Z TUESDAY/

Issued at 1237 PM CDT Mon May 18 2026

Mostly MVFR with local IFR ceilings will continue through the afternoon into most of tonight across western and north central Nebraska. Scatttered showers will be possible through this evening. Conditions will improve after 12Z Tuesday morning with skies becoming clear. Surface winds will be north at 10-20 kts through this evening then decreasing after 06Z Tuesday.

LBF WATCHES/WARNINGS/ADVISORIES

None.