Bertrand, Nebraska Weather Forecast Discussion

493
FXUS63 KGID 181144
AFDGID
Area Forecast Discussion
National Weather Service Hastings NE
644 AM CDT Thu Sep 18 2025
.KEY MESSAGES...
- Cloudy and cool today with areas of scattered showers and weak
  thunderstorms today.
- Rain chances have trended higher for the daytime hours Friday
  with one last upper disturbance rotating around the departing
  trough.
- Off and on 20-30% rain chances continue over the weekend, but
  the main story will be return of above normal temperatures
  and highs in the 80s.
- Another upper trough arrives early next week and brings a
  modest cooldown and more organized chances for rain.
&&
.DISCUSSION...
Issued at 405 AM CDT Thu Sep 18 2025
Early morning water vapor imagery indicates a complex closed
upper trough spinning over the N Plains...with several embedded
vorticity lobes spinning around the parent low supporting areas
of showers and thunderstorms. Short terms models have remained
consistent in showing the current area of showers in SW Kansas
shifting/expanding E/NE this morning and clipping at least the
SE third/half of the forecast area. Some additional, probably
less expansive, activity could develop further NW of the main
band, as well. Bottom line...expect some light to moderate rain
for portions of the area this morning...and areas that manage to
remain dry will still be under copious mid to high clouds.
Another source of rain chances particularly this aftn into early
eve will be moisture wrapping around the primary upper low
center along the SD/NE border. This activity will be supported
by modest sfc heating that leads to steeper low to mid level
lapse rates and more "pop-up" type isolated convection. Areas
from around the Tri-Cities, N and W, will be most favored. Rain
amounts will remain spotty and light. W-NW flow and copious
cloud cover will keep temps cool in the 60s to low 70s.
Mainly dry conditions return for the overnight hours tonight.
The break in rain chances will be short-lived, however, as
models have trended towards better agreement in another batch of
rain on Friday with another lobe of mid/upper level vorticity.
Have coordinated with surrounding offices to increase PoPs above
the NBM as it seems too slow in capturing this potential. HRRR,
RAP, RRFS, and EC...for example...all depict the general
scenario of a NW to SE band of showers/weak convection rotating
through the daytime hours. Have gone with 20-40 PoPs, for now,
but given the increasing consistency, the day shift may very
well ramp this up further with the afternoon forecast package.
The broader upper trough axis will gradually shift E/NE into the
Upper MS Valley for the weekend...but latest 500mb vorticity
progs still indicate pervasively "dirty" zonal to NW upper flow
that will keep occasionally unsettled weather going through the
weekend. These weak perturbations are notoriously difficult to
pinpoint timing and location, so details on timing, coverage,
and placement of convection are still very uncertain. Just know
that the weekend is trending "less dry" than 24-48 hrs ago, but
it`s not going to be a washout, either. The broader sensible
weather impact will be the return of above normal temperatures
in the 80s. Still think favored warm spots SW of the Tri-Cities may
even make a run toward 90F on Sunday. Dew point progs in at
least the mid 60s suggest seasonably high humidity, as well.
Various deterministic models and ensembles have remained
consistent with the general idea of a new upper
trough/disturbance in the NW upper flow arriving sometime early
next week. This could result in a period, or two, of more
organized shower/thunderstorm potential, followed by a dip in
temperatures towards Tue-Wed. The temp drop looks to be modest,
though, as the source of the upper level energy is largely
Pacific-based and any significant infusions of polar airmass
appears unlikely. The 00Z EPS mean progs highs in the 70s and
lows in the 50s Tue through the end of next week...so likely a
pretty mild/pleasant week next week outside of any rain chances.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 640 AM CDT Thu Sep 18 2025
For KGRI/KEAR Airports:
Today: Mainly VFR, though can`t rule out some instances of MVFR
CIGs - esp. this aftn - and VSBYs with any heavier showers.
Shower activity is forecast to be mainly iso-scat coverage, with
best chances late AM through late aftn. Some of the aftn
activity could have some rumbles of thunder. Most of the day,
CIGs should be 4-6K ft, or higher. Winds will be SW to WNW at
5-10 kt. Confidence: Medium.
Tonight: Expect clearing skies during the evening and VFR
conditions to prevail overnight. Winds will be WNW to WSW and
light at only 4-7kt. The Wrly component to the wind should
preclude significant fog concerns. Confidence: High.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
DISCUSSION...Thies
AVIATION...Thies

NWS GID Office Area Forecast Discussion