384
FXUS63 KLBF 181933
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
233 PM CDT Thu Sep 18 2025

.KEY MESSAGES...

- Scattered showers with a few thunderstorms remain possible
  through Thursday evening, mainly for northern Nebraska.

- Two rounds of showers and thunderstorms are probable on
  Friday, with some threat for severe weather during the late
  afternoon and evening.

- Temperatures warm this weekend into next week with a return to
  widespread 70s and a few instances of low 80s.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 233 PM CDT Thu Sep 18 2025

This afternoon, broad circulation focused over south central South
Dakota continues to drive local weather conditions. Northerly winds
on the backside of this feature will prolong CAA and keep
temperatures on the cooler side. Coupled with clearing skies and
decreasing winds, we should see one of the cooler nights set up
tonight with lows ranging from the middle 40s west to low 50s east.
Will insert a mention of patchy fog across our western zones where
HREF/SREF probabilities suggest one mile visibilities are possible.
Short term guidance, particularly the HRRR, suggests fog could be
particularly dense requiring headlines however confidence at this
time is limited so will forgo any headlines at this time.

Friday...a particularly active day with the potential for not one
but two rounds of thunderstorms to monitor. As the upper-level low
continues to spin across eastern South Dakota, a secondary PV
anomaly will rotate south on the backside of this feature. As the
main vort lobe tracks south-southeast from the Northern Plains,
isolated to scattered showers and a few thunderstorms should
accompany it out of southwest South Dakota. Timing appears to be
around sunrise through early afternoon with most if not all impacts
limited to areas northeast of an Ellsworth to Curtis line. While
shear will be adequate, instability will be limited with MUCAPE
generally < 1000 j/kg. This should preclude any threat for severe
early in the day. Later on, in response to a modest low-pressure
forming over eastern Colorado, a warm front will lift north into
southwest Nebraska boosting daytime highs into the middle 70s south
(low 60s north). Low-level convergence within modest moisture
pooling on the south side of this feature should increase enough to
yield a storm or two in our southwest zones. The Storm Prediction
Center has introduced a Marginal Risk (level 1 of 5) as a result.
Any storm that forms will do so in a narrow ribbon of ~1000 j/kg and
30-40 knots 0-6km BWD. This suggests a threat for severe hail and
damaging wind gusts. Any threat should be relatively short lived for
the local area with activity departing to the east-southeast by mid-
evening. Dry conditions resume by late evening into early Saturday
morning. Lows will be similar to the night previous with values in
the 40s to low 50s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 233 PM CDT Thu Sep 18 2025

This weekend...shortwave ridging will build in from the west behind
departing Northern Plains trough. Temperatures will slowly climb
with widespread 70s and a few locations making a run at 80F Saturday
before all locations climb to the 80s for Sunday. A warm front will
lift north late Saturday into early Sunday and may support some low-
end rain/thunderstorm potential. Ensembles remain fairly pessimistic
on this potential though some limited signals exist in probabilistic
output. The NBM initialized forecast included Slight Chance/Chance
(< 30%) PoPs. Believe this is adequate for now and will monitor need
to increase this with later forecasts. This activity would likely
include the potential for thunderstorms and given proximity to
stronger mid-level flow, will need to be mindful for the potential
of strong thunderstorms.

Next week...upper-level pattern becomes messy early next week. Upper-
level trough will linger near International Falls but should slowly
track east over the Great Lakes. Meanwhile, further west, the next
disturbance will exit British Columbia and dive east-southeast
across the central/northern Rockies sometime Monday/Tuesday.
Evolution of this system varies between deterministic guidance but
ensembles continue to point to late Monday into Tuesday with the
best potential for precipitation across much of the region. ECMWF
Extreme Forecast Index (EFI) suggests a small signal for an
anomalous rainfall event though this tends to favor west central
South Dakota. Ensemble higher percentile output, particularly the
GEFS, suggests fairly expansive wetting rains (0.25"+) though NBM
probabilities of the same remain limited to around 10-20%. Will need
to monitor this potential going forward. Overall, temperatures
appear set to be around (within 5F) of climatological values. It`s
worth nothing though that there is a right skew in the data
suggesting it`s more likely to see subsequent forecasts exhibit a
warming trend. With the populated temperatures remaining below the
median value, believe this will likely occur and some potential
exists to return to well above normal values for at least brief
periods in the time frame. This matches latest Climate Prediction
Center outlooks for the 6-10 and 8-14 day periods where above normal
temperatures are favored.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1239 PM CDT Thu Sep 18 2025

Lingering low-stratus will hamper aviation operations through
the forecast period.

Widespread MVFR with isolated IFR conditions persist across much
of western Nebraska. Increasing cloud breaks are visible on
satellite and these may lead to improving conditions this
afternoon at LBF while VTN, in closer proximity to the main
upper-level disturbance, is unlikely to see much if any
improvement. Tonight, winds diminish and with clearing upper-
level skies believe adequate radiational cooling will yield
expansive fog in our west. LBF appears set to remain on the far
eastern periphery of this fog deck so uncertainty remains,
however, will include a mention of IFR conditions to cover the
potential.

Conditions may improve some late morning at both terminals, but
confidence in timing is low so adjustments with later forecasts
will likely be necessary.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...NMJ
LONG TERM...NMJ
AVIATION...NMJ

NWS LBF Office Area Forecast Discussion