RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1123 PM CST Fri Nov 14 2025
Valid 151200Z - 161200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...
...SUMMARY...
Showers and a few thunderstorms may be accompanied by strong wind
gusts across parts of the upper Ohio Valley late this afternoon and
evening.
...Ohio Valley...
Strong large-scale midlevel height falls will spread across the
Great Lakes/Ohio Valley later today in advance of a short-wave
trough that will dig into the Great Lakes by 16/00z. Associated cold
front will surge to a position from southern ON-northern OH-central
IN by late afternoon and this feature is expected to serve as the
focus for isolated thunderstorms. Latest model guidance is not
particularly aggressive in boundary-layer destabilization with
surface temperatures forecast to warm into the lower 60s along the
OH river into southern OH, with upper 50s expected downstream across
western PA. These temperatures would yield a few hundred J/kg
uncapped SBCAPE by late afternoon within a strongly sheared
environment. HREF guidance suggests weak frontal convection should
evolve between 16/00-02z across eastern OH/western PA. This activity
will spread downstream, but likely weaken fairly quickly in the
absence of meaningful buoyancy over central PA. Strong wind gusts
are the primary concern.
...Southern CA...
Strong 500mb speed max will translate through the base of the
offshore trough toward the northern Baja Peninsula by 18z, with
high-level diffluent flow forecast across southern CA/lower CO River
Valley. Latest guidance suggests the associated cold front will
surge inland after 18z-19z, and cooling post frontal profiles will
lead to a bit more instability that should favor lightning within
deeper convective updrafts. Pre frontal convection is expected to be
weakly buoyant and updrafts should reflect this poor instability air
mass. While post frontal destabilization may lead to more robust
updrafts, weaker shear does not appear particularly favorable for
severe wind, but some small hail could be noted. Will not introduce
severe probabilities for these reasons.
..Darrow/Moore.. 11/15/2025
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SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1112 PM CST Fri Nov 14 2025
Valid 161200Z - 171200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms are possible from the Lower Colorado River
Valley into the Four Corners states on Sunday. Additional isolated
thunderstorms may approach the central California coast early Monday
morning. Severe storms are not expected.
...Western U.S...
An upper low and attendant trough over the western Great Basin and
Southwest states will pivot east/northeast toward the Rockies and
adjacent High Plains on Sunday/Sunday night. Moderate southwesterly
deep-layer flow ahead of this feature will overlap with midlevel
moisture and cooling aloft to provide weak instability. Isolated
thunderstorms will be possible from the Lower CO Valley into the
Four Corners states through evening as the upper trough progresses
east/northeast. A cool boundary layer and MLCAPE less than 500 J/kg
will preclude severe potential.
Another upper low offshore the Pacific coast will develop southeast
toward the northern/central CA coast last Sunday/early Monday.
Cooling aloft will allow for development of weak instability near
the central CA coast as a weak surface low and Pacific front move
inland near around 08-12z Monday. Low-topped convection may produce
isolated lightning flashes while 25-35 kt southwesterly low-level
flow could foster locally gusty winds. Poor lapse rates and meager
instability will preclude severe thunderstorm potential.
..Leitman.. 11/15/2025
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SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0107 AM CST Sat Nov 15 2025
Valid 171200Z - 181200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Isolated thunderstorms may occur Monday evening into early Tuesday
morning across parts of the Ozarks and Middle Mississippi Valley.
Severe thunderstorm potential appears low.
...Ozarks/Mid-MS Valley vicinity...
An upper shortwave trough over the central Rockies vicinity will
develop east into the northern Plains on Monday/Monday night. This
system will suppress upper ridging over the southern Plains into the
Mid/Lower MS Valley vicinity, though moderate westerly flow will
overspread OK/KS into the Mid-South. Given a more northerly trend in
the track of the upper shortwave trough, large-scale ascent will
remain displaced from modest Gulf moisture return across OK/TX
toward the Ozark Plateau.
At the surface, a weak low will progress across OK/KS toward the
Ozarks. Warm temperatures in the 850-700 mb layer will preclude
surface-based instability. However, cool temperatures aloft will
support weak MUCAPE and isolated elevated convection is possible in
the vicinity of the Ozarks to the Mid-MS Valley, mainly after 00z.
Some forecast soundings suggest small hail could accompany any
stronger cells that develop, but concerns over storm coverage and
intensity preclude severe probabilities at this time.
..Leitman.. 11/15/2025
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0245 AM CST Sat Nov 15 2025
Valid 181200Z - 231200Z
...DISCUSSION...
Upper-level ridging over the Plains on Day 4/Tue will develop
eastward over the eastern third of the CONUS through Day 5/Wed as a
western upper trough slowly ejects over the Rockies and into the
Plains around Day 6/Thu. Gulf moisture will return northward across
the southern Plains and south-central states ahead of the ejecting
upper trough. Isolated strong to severe storms may be possible on
Wednesday across the southern Plains and Ozarks vicinity in a warm
advection regime ahead of the upper trough. By Day 6/Thu, the upper
trough should progress east across the Plains toward the Mississippi
Valley, with a surface cold front sweeping eastward as this occurs,
and some severe potential could accompany widespread thunderstorm
activity ahead of the front.
Confidence in coverage of severe storms Day 5-6/Wed-Thu is
uncertain. Large spread (and poor run-to-run consistency) exists
among forecast guidance. The GFS and ECMWF-AIFS are more similar
compared to the dynamical ECMWF, indicating a slower ejecting trough
and only modest surface cyclogenesis until late Thursday when the
low ejects northeast toward the Mid-MS Valley/Great Lakes.
Furthermore, while strong southwesterly flow will overspread
northward returning Gulf moisture across the Plains and
south-central states, forcing for ascent will be somewhat limited on
Wednesday as the trough ejects more slowly. As the trough ejects on
Thursday and a cold front becomes a focus for storm development,
boundary-parallel deep-layer flow and a northeastward ejecting
cyclone may favor a more anafrontal, training convection/heavy
rainfall scenario. While severe potential certainly is in play for
Days 5-6/Wed-Thu, these uncertainties preclude 15 percent
probabilities at this time.
Beyond Day 6/Thu, model disparity increases substantially and
predictability is low.
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