264 FXUS63 KLBF 092317 AFDLBFArea Forecast Discussion National Weather Service North Platte NE 617 PM CDT Tue Sep 9 2025
.KEY MESSAGES...
- Strong to severe thunderstorms are possible this evening across southwest Nebraska and the Sandhills. Large hail and strong wind gusts will be the primary severe weather concerns.
- Temperatures remain warmer than average through the end of the week and into the weekend. A cold front this weekend brings seasonal temperatures for a day or two.
- The weekend cold front also brings our next best chances for appreciable rainfall across western and north central Nebraska.
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.SHORT TERM /THROUGH WEDNESDAY NIGHT/... Issued at 234 PM CDT Tue Sep 9 2025
A surface boundary is observed across central Nebraska this afternoon, with a corridor of ample moisture streaming across the Great Plains. The special 18z upper air flight at LBF shows a fairly shallow cap and over 3,000 surface based CAPE. While low level shear remains fairly meager, deep layer shear remains quite strong, supportive of discrete cells this afternoon and evening. As the cap erodes and storms form late this afternoon and evening, cells will be able to quickly grow, with the strongest storms posing a threat for large hail and gusty across the Sandhills and southwest Nebraska. With the supportive environment, a Marginal Risk (level 1 of 5) has been expanded into the Sandhills for this afternoon and evening. As we track further into the evening, the severe threat begins to dwindle, however, showers and thunderstorms will continue through the overnight hours across southwest Nebraska, mostly along and south of Interstate 80. Dewpoints remain high overnight, and given the generally calm surface winds, for development is likely tonight across most of southwest, central, and north central Nebraska. Along with the higher dewpoints, overnight lows remain in the upper 50s to lower 60s across the region.
Wednesday, an upper level high builds across central Texas, keeping the trough to the west and a ridge over western Nebraska. Cooler air trails in the wake of the surface boundary, keeping temperatures a bit cooler across portions of southwest and central Nebraska tomorrow, with highs expected in the low to mid 80s. To the northwest, slightly better daytime heating will allow for temperatures to climb into the mid to upper 80s. Dewpoints climb into the upper 50s to mid 60s across the region, keeping humidity values above 40 percent and limiting the fire weather concerns from the previous days. With the ridge in place, chances for showers and thunderstorms have decreased slightly, with a very localized slight chance of showers near Pine Ridge in the late afternoon and evening, driven mostly by daytime heating. With the robust dewpoints remaining in the region, overnight lows remain in the upper 50s to lower 60s.
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.LONG TERM /THURSDAY THROUGH TUESDAY/... Issued at 234 PM CDT Tue Sep 9 2025
Upper level ridging continues on Thursday and Friday, keeping our afternoon highs above seasonal averages. Widespread highs both days reach into the upper 80s across the region, with some areas breaking into the lower 90s. Upper level ridging and surface high pressure will limit precipitation chances through the afternoon hours both days. Dewpoints remain fairly robust across the region, with dewpoints remaining in the upper 50s to 60s. This will help keep our minimum humidity values above 30 percent throughout this slightly hotter period, again limiting fire weather concerns.
Late Friday into the weekend, the upper level trough tracks further east, bringing stronger winds aloft across the region. A cold front tracks through the region, bringing our next chances of appreciable rainfall. Ensemble guidance remains optimistic for wetting precipitation this weekend, bringing a 40 to 70 percent chance across northern Nebraska and the Sandhills, with around a 30 to 40 percent chance of wetting precipitation across southwest Nebraska. Will need to keep an eye on forecast trends through the week, as ample moisture and upper level flow this weekend may allow for some stronger thunderstorms to develop. Along with the rainfall, the cold front brings us back to near seasonal temperatures for at least Sunday, but depending on hwo quickly the front arrives, we could see more seasonal temperatures on Saturday as well.
As for early next week, guidance suggests we will be caught in between two upper level shortwaves. This does throw a little uncertainty into temperatures early week, with temperatures ranging from near normal to above normal. Much will depend on the timing of the second shortwave to the west. If it arrives later, could see some higher temperatures on Monday in particular. If it arrives ahead of what guidance suggests, we are more likely to remain near seasonal. Again, will need to keep an eye on the forecast trends over the next several days, as models and ensembles come into better agreement on the upper level pattern.
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.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/... Issued at 614 PM CDT Tue Sep 9 2025
VFR conditions are expected through the forecast period.
Main aviation concerns will be threat of ongoing convection moving in from the west followed by patchy fog early Wednesday morning. At this time, convection remains very slow moving and recent short-term guidance continues to paint little to no impacts at area terminals. Because of this, opted to omit mention at this time but LBF will be the greatest uncertainty so trends will be monitored. Late tonight, more patchy fog favoring central Nebraska appears probable. How far west this makes it and to what magnitude is somewhat in question. Have continued mention of low-end impacts at LBF though some potential for greater reductions in vsby and CIGs remains. Will monitor closely.
Thereafter, expecting a dry but blustery day Wednesday with southeast winds gusting around 25 knots during the afternoon.
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.LBF WATCHES/WARNINGS/ADVISORIES... None.
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SHORT TERM...Richie LONG TERM...Richie AVIATION...NMJ
NWS LBF Office Area Forecast Discussion