578
FXUS63 KLBF 162129
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
429 PM CDT Mon Sep 16 2024

.KEY MESSAGES...

- Windy conditions persist across central and western Nebraska
  tonight and especially through Tuesday. There is increasing
  potential for gusts at or above 45mph by late Tuesday
  afternoon.

- High confidence for thunderstorms with locally heavy rainfall
  to move out of the panhandle early Tuesday evening and
  continue moving across central Nebraska into early Tuesday
  night. Increasing potential for wind gusts at or above 60mph
  west of Hwy 83, and 75mph or higher from near Chappell thorugh
  Hyannis to near Merriman westward.

- While confidence still remains low, the potential for
  widespread rainfall this weekend is increasing across central
  and western Nebraska.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 425 PM CDT Mon Sep 16 2024

With central and western Nebraska remaining under largely the
same synoptic regime for the past several days, conditions
heading into tonight will be quite similar to the last few days.
There is a pool of unstable air across the region with CAPE
values around 2500J/kg generally west of I-80, though it is
difficult to realize this convective potential as a convective
cap remains in place. However a dry line just off to our west
will nudge eastward a bit to near Hwy 83 and as the low level
jet amplifies this should should provide enough lift to trigger
isolated/widely scattered thunderstorms this evening into
tonight. Streamlines currently show focused convergence to our
south from northeast CO into KS and meso guidance indicates
convection will initiate here and push up form the south this
evening. The best potential for thunderstorms will generally be
from Imperial through North Platte to Burwell and southward
though coverage will remain sparse. 0-6km bulk shear will be
sufficient to support some organization and there is sufficient
instability for an isolated storm to produce large hail. However
steep low level lapse rates and DCAPE values around 1400J/kg
will support efficient outflow production so expect strong
gusty winds from any convection. As the low level jet moves
eastward tonight it will take the convection with it and
eventually off to our east by daybreak.

Guidance has been quite consistent over the past few days
advertising a good signal for a hot windy day tomorrow.
Temperatures aloft into the 90th percentile will support
afternoon highs in the lower and middle 90s, while low level
winds are approaching the 99th percentile and EFI/ST guidance
maintains a signal supporting strong gusty winds across the
region. Given the strength of the low level flow in the mixed
layer evident in Bufkit, probabilistic guidance appears to be
underestimating gust potential as it caps the best probabilities
in the 35 to 40mph range. Expect a higher ceiling on gusts
tomorrow with gusts at or above 45mph by late Tuesday afternoon.
This will generate elevated to potentially near critical fire
weather conditions mainly west of Hwy 83 despite minimum
humidity values remaining above critical levels at 25 to 35
percent.

By late Tuesday, thunderstorms are expected to develop over the
high terrain to our west and move through the panhandle into the
western sandhills toward evening. The environment will remain
very favorable to support efficient wind production with steep
low level lapse rates and robust DCAPE values. Thunderstorms
will have potential to produce wind gusts at or above 75mph
mainly from near Chappell through Hyannis to near Merriman, with
potential for gusts at or above 60mph extending eastward to Hwy
83. Precipitable water values will also be rising into the 99th
percentile so storms are expected to produce widespread
rainfall with locally heavy downpours. The storms will be moving
rather quickly and look to be exiting the region to the east
shortly after Midnight.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 425 PM CDT Mon Sep 16 2024

Confidence remains high in the overall blocky pattern prohibiting
an initial deep trof moving in from the Pacific from making
eastward progress past the Rockies and forcing it northward
into Canada, followed by a second deep cutoff low that will have
more success moving across the mountains and into the Plains
this weekend. Ensemble guidance seems to be trending toward a
solution favoring the low to pass over or just south of Nebraska
this weekend, which is favorable for widespread precipitation
across the region. However there is still considerable spread in
QPF plumes so confidence remains low, and the exact track of
the surface low will determine if there is any threat for severe
storms. EFI/SoT guidance has a QPF signal which supports the
concept of a low confidence event with little agreement in
ensemble members, though any event may potentially be
significant with large positive departures from the internal
ensemble system mean. So after a brief break with mostly dry
conditions Wednesday and Thursday, expect a return to unsettled
conditions with potential for showers and thunderstorms Friday
and continuing through the weekend with potential for impactful
weather Saturday and Sunday. There is higher confidence in the
temperature regime with temperatures at or above normal through
the latter portion of next week, becoming cooler with readings
below normal for the weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1250 PM CDT Mon Sep 16 2024

An area of broken MVFR ceilings extends south to north along the
Hwy 83 corridor. These should gradually lift this afternoon.
Otherwise VFR conditions should prevail through tonight. Low
level wind shear will once again be a concern overnight tonight,
especially to the east of Hwy 83. Winds will also be gusty from
the south to southeast this afternoon through tonight and into
Tuesday.

&&

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

&&

$$

SHORT TERM...MBS
LONG TERM...MBS
AVIATION...Taylor