597
FXUS63 KLBF 030829
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
329 AM CDT Sun Aug 3 2025

.KEY MESSAGES...

- Scattered thunderstorms including the threat for a few strong
  to severe storms are possible each day Sunday through
  Tuesday.

- Precipitation chances wane as heat builds by the middle of the week
  with upper 90s to near triple digits likely for Thursday and
  Friday.

- A frontal boundary will arrive by late week with cooler
  temperatures and greater chances for rain and thunderstorms.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 329 AM CDT Sun Aug 3 2025

This morning...an expansive shield of rain and thunderstorms
continues to slowly drift east across central and eastern Nebraska.
This activity was being driven by a stout low-level jet (LLJ) nosing
into eastern South Dakota. As of 0730z (230am CDT), precipitation
had largely cleared our north central Nebraska zones and so will
keep only low-end PoPs (< 25%) to account for any additional new
development further west. Believe this potential should quickly wane
by late morning.

This afternoon, a weak warm front stalled north to south across the
Nebraska Panhandle will settle east into portions of west central
Nebraska. Daytime highs will largely depend on placement of this
boundary with warmer values in the upper 80s to the west and upper
70s to lower 80s to the east. A weak circulation will form along
this baroclinic zone and lead to increasing low-level convergence
during the afternoon. With southerly flow across central Nebraska,
expect reinforcing moisture to advect in with dew points expected to
reach the middle 60s. Beneath steep mid-level lapse rates, moderate
destabilization will occur with MUCAPE values in the 2000-3000 j/kg
range. Weak mid-level flow will stunt deep layer shear but given the
magnitude of instability, still cannot rule out a few stronger to
briefly severe storms this afternoon. Initiation should favor the
low-level frontal boundary as convergence increases in the
afternoon. Storms should erupt in a southwest to northeast line.
Initial updrafts may support isolated severe hail up to 1.50" but as
storms collapse believe the threat will transition to damaging
winds. HREF probabilities show rapid increase in echo top heights
with just as quick a decrease this evening. This suggests a fairly
brief window for strong to severe storms. The Storm Prediction
Center (SPC) keeps a Marginal Risk (level 1 of 5) in place across
the whole of the forecast area. Precipitation should diminish
through the evening though isolated activity may persist into early
Monday morning.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 329 AM CDT Sun Aug 3 2025

Monday...daily threat for strong to severe thunderstorms continues
with moderating daytime temperatures as highs begin their steady
increase and rise to the 80s to lower 90s east to west. Southwestern
ridging will amplify heading towards the middle of the week.
Subsequent mid-level height rises and subsidence aloft should
largely quell precipitation chances across the area. The lone
exception to this will localized lift off topography that could
support at least isolated initiation as forecast soundings show the
cap eroding across the Sandhills with daytime heating. Believe
southeasterly flow at the surface should be enough to produce a few
storms off the higher terrain of the Pine Ridge and/or Black Hills
but given isolated nature will keep PoPs capped at Slight Chance (<
25%). As a mid-level disturbance rounds the ridge, flow aloft will
increase and coupled with the low-level southerly flow will promote
moderate deep-layer shear supportive of supercells. Damaging winds
and large hail will be the main concerns with NAM forecast soundings
showing numerous significant hail analogs. SPC keeps a Marginal Risk
in place stretching along the Nebraska/South Dakota border then
turning south to northeast Colorado. Am in general agreement with
this outlook for now. Will need to monitor the severe potential
closely going forward.

Tuesday...weak surface trough will extend south from the Black Hills
with strong southerly flow across much of west central Nebraska.
This will promote upper 60s to low 70s dew points and coupled with
daytime highs climbing into the middle 80s to middle 90s, strong
destabilization is likely to develop. Shear again appears supportive
of rotating updrafts. Once again believe large hail and damaging
wind gusts will be the primary concern, however, given relatively
low LCLs and increasing 0-3km SRH in the evening, will have to
closely monitor the potential for all hazards being in play. Similar
to Monday will be the uncertainty of storm initiation given
strengthening mid-level ridging and lack of greater forcing for
ascent. Deterministic solutions suggest little to no development
during the afternoon and similarly, ensemble guidance keeps low
probabilities of seeing > 0.10" for the day. Am in agreement with
SPC`s Marginal Risk given the background environment but uncertainty
in storm development. Again, will monitor closely going forward.

Wednesday and beyond...quieter weather arrives for the late week as
mid-level high pressure peaks across the southwest during this time.
By Wednesday evening, GEFS suggests h5 heights exceeding 2 standard
deviation across the Desert Southwest. Similarly, h7 temperatures
will exceed the 99th percentile across the region by Thursday. ECMWF
Extreme Forecast Index (EFI) highlights positive anomalies across
the Front Range extending east into the Nebraska Panhandle for
daytime highs Thursday and Friday. The latest forecast has portions
of the area exceeding 100F heat indices. Should this remain
unchanged in the coming days, heat headlines will likely be
necessary. After dry to mostly dry days Wednesday and Thursday,
increased rain and thunderstorm probabilities arrive late Friday as
the ridge breaks down and a stronger disturbance tracks out of the
Pacific Northwest. This will propel a frontal boundary south into
the area and lead to cooler temperatures for the weekend. Whether
those cooler temperatures initially arrive Saturday or Sunday
remains somewhat in question.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1227 AM CDT Sun Aug 3 2025

VFR conditions are expected to prevail across western and north
central Nebraska throughout the effective TAF period. A stationary
front tracks into the region tomorrow, and is expected to settle
around the KVTN terminal. This will create near variable winds
during the afternoon and evening at KVTN, but for now, tried to
catch the prevailing wind groups. Additional showers and
thunderstorms may develop along the front and across the Sandhills
in the afternoon and evening, however, confidence is low on impacts
to terminals, so will omit the thunder mention at this time.

&&

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

&&

$$

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