332
FXUS63 KLBF 172110
AFDLBF
Area Forecast Discussion
National Weather Service North Platte NE
410 PM CDT Mon Aug 17 2026
.KEY MESSAGES...
- Isolated to widely scattered severe thunderstorms will be
possible tonight.
- A cold front will tend to focus the severe potential more
across Kansas Tuesday
- Strong to severe thunderstorms are possible again Wednesday.
Locally heavy rainfall will also be possible given the moist
environment.
- Warmer and drier conditions return Friday into the weekend as
an upper-level ridge strengthens across the region.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 339 PM CDT Mon Aug 17 2026
Appears to be a residual outflow boundary from earlier convection
that has settled across the southern Sandhills this afternoon. This
will be one area to watch for possible convective initiation late
this afternoon. The other area to watch will be development across
southwest into south central South Dakota. CAMs have been more
aggressive with this activity, and move it into northern Nebraska
this evening (mainly east of Highway 183). This would be round one,
with another potential late night round tracking virtually across
the same area of north central Nebraska. If two rounds do indeed
occur across the same area will have to monitor for some locally
heavy rain potential. As far as severe, deep layer shear is more
than adequate for storm organization. A couple of initial supercells
could emerge out of a deepening CU field late this afternoon into
this evening near the aforementioned outflow boundary. CAMs have
struggled with the evolution of this scenario. The storm
organization across southern South Dakota is more certain, with
multiple runs of the HRRR showing at least a couple of rounds of
potential intense convection. The main risks would be from damaging
winds and large hail. The overall tornado risk is low.
A cold front will sag southward into Kansas Tuesday. Although some
isolated shower and thunderstorm activity will be possible during
the day, the better focus for afternoon development would be south
of the area nearer the cold front across Kansas. Other storms may
move off the higher terrain into northwest Nebraska during the
evening...and these could continue eastward overnight. At this time,
this activity doesn`t look like it will be overly strong, with the
better focus remaining to the south overnight.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 339 PM CDT Mon Aug 17 2026
Wednesday, an upper-level longwave trough will become established
across the Great Lakes and Hudson Bay region, resulting in northwest
flow aloft across the area. Along the southwestern periphery of this
trough, a weak disturbance will move through the region. Surface dew
points in the mid to upper 60s, combined with sufficient mid and
upper-level forcing, will support shower and thunderstorm
development across portions of the area. In terms of severe weather,
MUCAPE values of 2000 to 3000 J/kg combined with 40 to 45 knots of
deep-layer shear should support organized convection, with large
hail and damaging winds the primary threats. The SPC currently has
much of the forecast area in a Marginal Risk for severe weather
Wednesday, and this period will continue to be monitored closely
over the next several forecast cycles. Moisture profiles will also
remain quite impressive, supporting efficient rainfall processes and
the potential for locally heavy rainfall with stronger
thunderstorms. Temperatures Wednesday will remain on the cooler
side, with highs generally in the mid to upper 70s across much of
the area.
Thursday, the longwave trough across the Hudson Bay region will
continue to shift east as an upper-level ridge builds across the
western United States, maintaining northwest flow aloft across the
region. Warm air advection will begin to increase as the western
ridge amplifies, with 850-mb temperatures returning to the 20 to 25C
range. This will support warmer surface temperatures, with highs
returning to the mid 80s across much of the area. Another weak
disturbance is forecast to move southeast through the northwest flow
on the backside of the departing longwave trough, potentially
providing sufficient lift for scattered showers and thunderstorms
Thursday afternoon and evening. Severe weather may again be possible
given sufficient instability and deep-layer shear. However,
strengthening 850-mb warm air advection may result in a stronger
cap, potentially limiting convective initiation. This period will
continue to be monitored over the next several forecast cycles.
Friday into the weekend, the upper-level ridge across the western
United States will amplify and gradually shift east toward the
region. Increasing subsidence associated with the amplifying ridge
should favor drier conditions, while the stronger upper-level flow
and better forcing remain north and east of the area. Temperatures
will also trend warmer, with highs returning to the lower to middle
90s across western portions of the forecast area through Monday,
while north-central Nebraska remains somewhat cooler with highs
generally in the lower to middle 80s. By early next week, the upper-
level ridge is forecast to begin flattening, resulting in a
transition toward more zonal flow and potentially allowing stronger
upper-level flow to return to the region.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1258 PM CDT Mon Aug 17 2026
VFR conditions will prevail across all of western and north
central Nebraska through tonight and into Tuesday morning. There
is a signal for some lower MVFR ceilings to develop west of
departing thunderstorms across central and portions of north
central Nebraska early Tuesday morning. Otherwise scattered
thunderstorms should develop this evening, and as mentioned,
depart the area later tonight.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Taylor
LONG TERM...Labenz
AVIATION...Taylor
NWS LBF Office Area Forecast Discussion