438
FXUS63 KLBF 070859
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
359 AM CDT Mon Jul 7 2025

.KEY MESSAGES...

- An Enhanced Risk (level 3 of 5) is in place Monday across much
  of western and central Nebraska with a threat for significant
  severe weather possible.

- Strong to severe thunderstorms are possible again Wednesday
  and Thursday, though precise details remain uncertain.

- Following a brief heat wave around the middle of the week,
  temperatures fall to below normal values for the start of the
  weekend.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 359 AM CDT Mon Jul 7 2025

The main concern in the short term will again focus on the threat
for severe weather including potential significant severe weather
(2"+ hail, 75+ mph gusts, a tornado or two.

This morning, anvil blowoff from storms across Colorado and western
Kansas continue to overspread the area. The clearing line is
arriving into our northwest zones. Upstream, convection is tracking
east across far western South Dakota. This is being driven by a weak
shortwave trough and associated WAA. Morning high resolution
guidance is failing to resolve this activity very well. The
background environment shows a modest LLJ across our western zones
but this feature is pointed into southwest South Dakota. Through
time, this belt of stronger flow should weaken through sunrise and
winds veer. Though shear vectors point into our northern zones,
weaker instability and stronger inhibition should prevent a repeat
of Sunday morning and keep activity north across South Dakota.

Today/tonight...as mentioned, strong to severe thunderstorms are
likely today for much of the region. The SPC has maintained the
Enhanced Risk (level 3 of 5), suggesting higher confidence in
coverage and occurrence. Modest ridging remains in place immediately
west of the Continental Divide as the next trough begins to move
onshore the California Coast. Closer to home, a northern stream
disturbance will track east across Montana and into the Dakotas. As
this disturbance moves east, a frontal boundary reinforced by
surface high pressure will settle south into South Dakota. Southerly
flow ahead of this boundary will reinforce a moisture rich
environment. As afternoon highs climb into the 80s to near 90F
beneath a strong EML with steepening mid-level lapse rates nearing
8.5 C/km, ample instability will develop to the tune of 2500-3500
j/kg MLCAPE. Storms should initiate in two areas by early afternoon:
over western South Dakota along this boundary and along the
Front Range to the west. With h5 flow nearing 30-40 knots and
southerly surface flow, a moderately sheared environment will be
in place across the warm sector. Forecast soundings show decent
low-level curvature with long/straight profiles above 1km. This
would suggest splitting supercells. The combination of steep
mid-level lapse rates, strong low-level inflow, LI values
nearing -10C, and CAPE distribution with much of it above the
freezing level supports the risk of very large hail. This would
be maximized with any discrete supercell. As the LLJ increases
later in the day, hodographs will enlarge with improving low-
level helicity particularly over north central Nebraska with
progged values to exceed 100 j/kg by early evening. Adding to
this, QLCS tornadoes appear possible later in the evening with
0-3km shear vectors showing ~30 knots line normal shear to any
potential MCS. This suggests the tornado potential could persist
even beyond the window for discrete convection. Upscale growth
appears likely as cold pools merge and progress quickly to the
south and east. Though hail and tornado threat should continue
through the evening, a transition to primarily a damaging wind
threat appears likely. SPC shows damaging wind potential as main
motivator for the Enhanced Risk and am in agreement on this.
Various CAMs showcase expansive severe wind gusts and pockets of
significant magnitudes (75+ mph). Believe this will carry
through the evening as one, possibly two mature MCSs track
through the area. Leaned heavily on NSSL WRF for PoPs which has
two distinct areas of 50%+ merging together this evening. Recent
HRRR runs have begun to advertise a similar evolution of storms
today, adding to the confidence in the PoPs forecast. As seen in
recent days, moisture availability remains at a premium.
Precipitable water values remain high, roughly 100-125% of
seasonable norms. This suggests the threat for heavy rain again.
HREF neighborhood probabilities of seeing > 0.75/hour rain rates
near 50% across north central Nebraska and various deterministic
solutions suggest expansive 0.25" rainfall with pockets of
heavier amounts potentially approaching 2.00". Feel this is
fairly representative of what is expected. While this shouldn`t
lead to widespread hydro concerns, localized flooding is
possible, especially in typical problem spots. Convection
appears set to depart the area by early morning Tuesday. Lows
tonight should fall into the 50s as cooler air works in from the
north.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 359 AM CDT Mon Jul 7 2025

Tuesday and beyond...upper ridging to the southwest will amplify
towards the middle of the week. The local area will reside on the
northeast periphery of the upper-level high pressure, leading to
general northwesterly flow aloft. Dry conditions are likely Tuesday,
siting subsidence aloft and increasing mid-level heights.
Temperatures may see a slight bump, but should be comparable to
Monday`s values. By Wednesday, a shortwave disturbance will begin to
impinge on the ridge which will foster height falls across the area
through the day. High temperatures should peak on Wednesday with
values in the middle to upper 90s. Do believe some heat concerns
will come into play as dew points appear set to climb into the
middle 60s. At this time, no Heat Advisory criteria is in the
forecast but subsequent forecasts will need to closely monitor this
period going forward. The increased moisture will also foster
greater potential for rain and thunderstorms. At this time, will
need to monitor the threat for severe both Wednesday and Thursday.
For now, confidence in occurrence is highest on Thursday where the
SPC paints a 15% from central Nebraska up through North Dakota. A
secondary trough will arrive by late week and should effectively
shunt the dome of high pressure aloft south. This will lead to
cooler temperatures with ECMWF Extreme Forecast Index (EFI)
suggesting a flip from positive anomalies on Wednesday/Thursday to
negative anomalies by Saturday. This is most apparent on Saturday
morning where EFI values fall to around -0.8 with non-zero shift of
tails. The going forecast for both LBF/VTN suggests daytime
temperatures falling to around the 10th percentile in their recorded
history so it`ll certainly be on the cooler side for July.
Temperatures should moderate quickly with a return to above normal
values by the following week. Latest forecast values inherited from
the model blend hugs the lower end of the forecast envelope so there
remains potential for further increases in the coming days.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1051 PM CDT Sun Jul 6 2025

Expect some broken high cloudiness to persist into the overnight
hours before scattering out around daybreak Monday. For most of
the day Monday, skies will be mostly clear with a few to
scattered high cloudiness around 25000 FT AGL. The threat for
thunderstorms will increase mid afternoon Monday and will
persist through Monday evening. There will be a decent threat
for severe storms with gusty winds, moderate to heavy rainfall
and visibilities down to 2 to 4 miles. The main threat will be
from 21z to 03z for the KVTN terminal and from 22z to 04z for
the KLBF terminal.

&&

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

&&

$$

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