803
FXUS63 KLBF 011707
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
1207 PM CDT Fri Aug 1 2025

.KEY MESSAGES...

- Severe weather concerns continue with Slight Risks (level 2 of
  5) each day Friday and Saturday for portions of far western
  Nebraska.

- Temperatures remain below normal through the weekend before returning
  to upper 80s and low 90s early next week.

- Precipitation chances look to decrease towards the middle of
  next week as broad upper ridging builds across the central and
  southern Rockies.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 325 AM CDT Fri Aug 1 2025

Main forecast concern in the short term revolves around the threat
of severe thunderstorms this afternoon and evening. The Storm
Prediction Center (SPC) has issued a Slight Risk (level 2 of 5) for
west of Highway 61 with a Marginal Risk (level 1) extending east to
approximately Highway 83.

This morning, isolated to widely scattered thunderstorms extend
south out of southern South Dakota. This activity was developing on
the western fringe of a modest LLJ where convergence was maximized.
Storms are failing to become overly robust as instability remains
relatively weak at or below 500 j/kg MUCAPE. Because of this, no
severe weather is expected. Expecting focus to remain greatest
across central South Dakota where the LLJ will point. Leaned heavily
on HRRR guidance for PoPs, which decreases coverage quickly around
sunrise and keeps only an isolated shower or weak thunderstorm in
the local area throughout the bulk of the daytime hours. Breezy
south winds will gust around 30 mph, perhaps approaching 35 mph in
the eastern Panhandle. These stronger winds will support sustained
low-level mugginess with dew points hovering in the low to middle
60s. Off the surface, moisture fetch should promote sustained
stratus for much of the day. This will hamper daytime heating and
allow for another below normal temperature day for western and
central Nebraska. NBM ensemble guidance paints expansive cloud cover
with even mostly cloudy to overcast conditions from the lower
percentile outputs. With the lack of insolation, expecting another
day in the 70s to perhaps a few locations reaching the low 80s in
southwest Nebraska. Leaned on statistical guidance plus a slight
boost from deterministic NAM output for today`s high temperatures. The
coolest values will favor the western Sandhills where low 70s are
forecast with our far southwest zones reaching 80F.

Even with the cooler temperatures, the environment will still be
supportive of a severe weather threat. Westerly flow aloft will
advect in an EML with steep mid-level lapse rates overspreading the
area. While it appears likely that any residual capping will be
unlikely to fully erode, southeasterly flow along the I-25 corridor
should allow convection to develop off the higher terrain. With
general westerly h5 flow, expect storms to push off the higher
terrain quickly and into western Nebraska as early as late afternoon
but more likely by the evening. Forecast soundings show nominal deep-
layer shear for storm organization. While forecast soundings show
fairly impressive hodographs, particularly this evening as the LLJ
ramps up, storm mode will likely favor a damaging wind threat with
DCAPE values climbing to around 1000 j/kg and 0-3km theta-e
differences approaching -25C. HRRR/NSSL WRF both show clusters and
bowing segments track through southeast Wyoming into northeast
Colorado/southern Nebraska Panhandle. This closely matches the
latest PoPs forecast which maxes around 50% in our southwest zones
and decreases closer to 30% north towards the South Dakota border.
Though the severe threat should wane later into the overnight
Friday/Saturday morning, another impressive LLJ should maintain
precipitation chances through daybreak Saturday for areas east of
Highway 83. Deterministic solutions vary on precise placement of
best rain/thunderstorm potential so will maintain Slight Chance (<
20%) for most locations until closer to daybreak.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 325 AM CDT Fri Aug 1 2025

Saturday/Sunday...active weather continues through the upcoming
weekend. Daytime highs should return to the 80s for our western
zones but remain cooler in the upper 70s across the east. Low
amplitude ridging remains in place across the southwest CONUS. High
pressure will settle east across the Great Lakes but southerly flow
will remain prevalent beneath high pressure aloft. A weak
perturbation within the mid-level flow will track east out of
Wyoming late Saturday. This will be coincident with peak heating
across the High Plains. Beneath steep mid-level lapse rates and
modest h5 flow around 20-30 knots, moderate instability will develop
with adequate deep-layer shear to support organized convection.
Storms appear likely to form off the Cheyenne Ridge and dive
southeast into a modest LLJ. The latest SPC Day 2 highlights a
Slight Risk (level 2 of 5) for areas along and south of the North
Platte River and west of Highway 25. Storm coverage appears to be
greatest in this area as low-level flow weakens further north.
Generally agree with SPC`s placement of the Slight Risk. Damaging
winds appear to be the greatest concern as forecast soundings show
deeply mixed boundary layers with weak flow within the lowest 3km.
While initially discrete storms may promote a greater hail threat,
believe this is maximized west of the local area and should largely
have ended prior to arriving in western/southwestern Nebraska due to
storm merger as cold pools merge. Storms will favor late afternoon
and the evening with the severe threat likely ending prior to
midnight as storms exit to the east. For Sunday, a weak surface
boundary will settle south out of South Dakota and stall around the
Nebraska/South Dakota border. Locally, low-level flow will remain
weaker and with increasing heights aloft, believe storm coverage
will be more limited. With weaker shear but moderate instability yet
again, believe a few stronger to brief severe storms are possible.
Latest SPC Day 3 outlook matches my thinking with only a Marginal
Risk (level 1 of 5) and this effectively summarizes the limited
confidence.


Monday and beyond...ridging across the Desert Southwest will amplify
through the early part of the week. Heights locally begin to climb
markedly by Tuesday with NAEFS guidance highlighting mid-level
values quickly exceeding the 90th percentile by Wednesday. This
coincides with an end to negative anomalies in daytime temperatures
as well as decreases probabilities of precipitation in various
ensemble solutions. The latest NBM solution shows steady climbs in
the 25th-75th range with deterministic solutions closely hugging the
higher end of the forecast envelope. The going forecast as a result
paints expansive 90s by Wednesday and even a few locations making a
run at the triple digits. Ridge breakdown appears probable to occur
during the latter half of the week, though more precise timing
appears low confidence at this time. Around late week, a frontal
boundary will settle south into the area and reintroduce greater
precipitation potential to the area. Temperatures as a result should
cool somewhat though they appear likely to remain near seasonal
norms.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1207 PM CDT Fri Aug 1 2025

Expect MVFR ceilings to persist at the KLBF terminal
through mid afternoon with ceilings lifting to 4500 FT AGL after
20z. MVFR ceilings will move back into southwestern Nebraska,
impacting the KLBF terminal after 03z this evening. Look for
lower ceilings to persist into mid morning Saturday before
lifting to around 2500 FT AGL by late morning. There will be a
threat for storms this evening with the main threat west and
southwest of the terminal. Given the low threat for storms, will
forgo mention with this forecast package.

For the KVTN terminal: Skies will remain mostly cloudy this
afternoon with MVFR ceilings rising to VFR ceilings after mid
afternoon. After broken ceilings of 3500 to 5000 FT AGL,
ceilings will fall to MVFR levels of 1500 FT AGL after 06z this
evening. Skies will remain mostly cloudy into Saturday morning
with ceilings reaching around 5000 FT AGL after mid morning.

&&

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

&&

$$

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