359
FXUS63 KLBF 201110
AFDLBF
Area Forecast Discussion
National Weather Service North Platte NE
610 AM CDT Thu Aug 20 2026
.KEY MESSAGES...
- Patchy dense fog is possible this morning across portions of
southwest and central Nebraska. Visibility may drop under one
mile at times.
- Strong to severe thunderstorms are possible this afternoon
and evening across portions of north central Nebraska, mainly
east of Highway 83. The main threats will be large hail and
potential for damaging wind gusts.
- Another round of severe weather is possible on Friday
afternoon and evening. The main threats remain large hail and
potential for damaging wind gusts.
&&
.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 330 AM CDT Thu Aug 20 2026
High pressure remains across most of the region this morning, with
forecast soundings indicating a strong inversion through the
overnight hours into the morning. Dewpoints are expected to remain
relatively high, in the upper 50s to lower 60s, providing ample low
level moisture underneath the inversion. In addition to all of this,
surface winds remain light and variable into the morning hours. All
of this increases the potential for patchy dense fog to develop,
remaining into the mid morning hours. While the signal for fog
development remains strong, there is still some question on how low
visibility will drop. The latest probabilistic guidance brings
around a 30 to 50 percent chance of visibility dropping less than
one mile, but also remains similar for visibility under one quarter
mile. Given the uncertainty in how dense the fog will get, have
opted to hold off on issuing a Dense Fog Advisory at this time, but
will continue to monitor through the night to determine whether one
is necessary. At the very least, expect to see some fog around dawn
and into the mid morning hours, with rapidly changing visibility
conditions expected. This will be especially true along river
valleys, low lying areas, and lakes.
The ample moisture is expected to stick around, and with highs
climbing into the upper 80s to lower 90s this afternoon, should see
strong instability again building across the region. Will need to
see how long fog and potential low stratus lingers this morning, as
that may limit some of the higher end amounts. However, by mid
afternoon, this should still result in around 3,000 to 4,000 J/kg of
surface based CAPE, with around 40 knots deep layer shear. A surface
cold front tracking south this afternoon is expected to be the
catalyst for storm development, with greatest chances for storm
development across north central Nebraska east of Highway 83. As the
environment will support supercells, expecting the main threat will
be large hail. However, cannot rule out the threat for damaging wind
gusts, as well.
Friday, another round of severe weather is expected across the
region. Very much like the previous few days, dewpoints remain in
the 60s, providing plenty of low level moisture for additional storm
development. Again, expecting temperatures to climb into the Upper
80s to lower 90s. This should again result in around 3,000 to 4,000
J/kg of surface based CAPE across the region. However, the main
difference on Friday will be the presence of a jet streak tracking
across portions of central and eastern Nebraska throughout the
afternoon and evening. This will enhance the deep layer shear across
the region, strongly supporting supercellular convection. With
supercells again in play, expect that the main threats will remain
large hail and damaging winds. However, latest forecast soundings
and hodographs do suggest some enhancement in the low level
helicity, so cannot completely rule out the possibility for a
tornado or two on Friday afternoon, either. At the very least, make
sure to have multiple ways to get weather updates and warnings on
Friday. If the forecast remains on track, it could be a very active
afternoon and evening across the region.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 330 AM CDT Thu Aug 20 2026
Upper ridging across the Rockies begins to slowly amplify into the
weekend, with the ridge axis beginning to move into the Plains by
Sunday night. This will lead to warmer temperatures both Sunday
and Monday, with highs in the lower 90s across western and
southwest Nebraska. The approach of this ridge axis will also
finally lead to weaker flow aloft, and lesser wind shear for at
least a couple of days across the area. This suggests a brief
reprieve from the recent daily threat for strong to severe
storms. That said, sub-severe thunderstorms cannot be ruled out
each day as we head into the weekend.
As we head into next week, the upper ridge begins to flatten out
across the southwestern US and brings a return of increasing
northwesterly flow aloft across the Plains. This could bring a
return of a threat for strong to severe storms, as wind shear
increases again in response to the strengthening northwest flow.
Mesoscale details will need to be resolved with respect to this
threat, though it appears the active pattern will continue across
the area as we head into next week.
&&
.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 615 AM CDT Thu Aug 20 2026
Low stratus and fog persists through late morning for terminals
along and east of HWY 83, with IFR/LIFR CIGs and visibilities
continuing. By late this morning, fog and stratus will quickly
erode and VFR conditions are expected to then prevail for all
terminals into tonight. Isolated thunderstorm development
remains possible east of HWY 83 this evening, with brief MVFR
visibilities and gusty, erratic winds possible.
Winds remain southerly today and tonight, at 5 to 10kts.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 10 AM CDT this morning for NEZ010-028-
029.
&&
$$
SHORT TERM...Richie
LONG TERM...Brown
AVIATION...Brown
NWS LBF Office Area Forecast Discussion