RSS Mesoscale Discussions from Storm Prediction Center
SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0203 AM CST Thu Nov 20 2025
Valid 221200Z - 231200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms are possible from the Southwest into the
southern Plains and Southeast, though severe thunderstorm potential
appears low.
...Synopsis...
An upper low and attendant trough will overspread the Southwest on
Saturday while shortwave upper ridging develops over the
southern/central Plains. At the surface, a cold front will develop
southeast across the TX coast and much of the Southeast U.S.
Isolated thunderstorms will be possible along the front amid a
modestly unstable and moist boundary layer. Severe storms are not
expected given limited instability and weak vertical shear.
Additional thunderstorms are possible across portions of the
Southwest where cold temperatures aloft will support meager but
sufficient MUCAPE.
Model spread increases late in the period regarding the ejection of
the Southwest upper trough. Some guidance suggests a low-level jet
will strengthen across the southern High Plains vicinity as the
upper trough approaches the vicinity toward Sunday morning.
Increasing midlevel moisture within deep-layer southwesterly flow,
and modestly steepening midlevel lapse rates could generate enough
elevated instability for isolated thunderstorm development across
the southern High Plains overnight, though severe storms are not
expected.
..Leitman.. 11/20/2025
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0309 AM CST Thu Nov 20 2025
Valid 231200Z - 281200Z
...DISCUSSION...
...Days 4-6/Sun-Tue -- Southern Plains to the TN Valley...
An upper low and attendant trough over the Southwest/northern Mexico
will eject east into the Plains by early Day 5/Monday. Gulf
moisture will spread northward across portions of TX into the Lower
MS Valley through early Tuesday. This moisture return will occur
ahead of the ejecting trough/increasing deep-layer southwesterly
flow, and a cold front sweeping across the region. Warm advection
will support thunderstorm development by late Sunday as the upper
trough and cold front begin to march across TX, and some hail risk
could accompany this activity. However, storm mode could preclude a
greater risk, and storm coverage/intensity is uncertain given
overnight timing.
As this system continues east across the ArkLaTex into the Lower MS
Valley on Monday, some severe potential could persist into these
areas. However, uncertainty regarding moisture return and degree of
destabilization due to potentially ongoing and widespread training
precipitation precludes severe probabilities at this time. Some risk
could continue across parts of the TN Valley/Southeast into Tuesday.
However, the upper trough is expected to be weakening and lifting
well north of the region by this time.
...Days 7-8/Wed-Thu...
The surface front will move offshore on Day 7/Wed and strong surface
high pressure will build across much of the CONUS. This will result
in dry and colder conditions, leading to a stable airmass. Severe
potential appears low mid to late in the week.
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