SPC 2000Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0142 PM CST Fri Nov 21 2025

Valid 212000Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
MS/AL/TN/KY...

...SUMMARY...
Isolated strong to severe storms are possible today and tonight
across parts of Mississippi and Tennessee into western and northern
Alabama and possibly southern Kentucky.

...20Z Update...
The Marginal Risk was trimmed slightly in northern/central MS, where
a combination of relatively weaker large-scale forcing for ascent
and poor deep-layer lapse rates/modest buoyancy (see SHV 18Z
sounding) should limit the severe-risk compared to areas farther
north tonight. Elsewhere, widely scattered thunderstorms are
evolving along a southeastward-moving cold front in southeast TX.
PBL destabilization ahead of the front has yielded moderate
surface-based buoyancy (per CRP 18Z sounding). While several warm
layers aloft and modest deep-layer shear (around 30 kt of effective
shear) should limit updraft intensity, a strong storm or two capable
of producing gusty winds cannot be entirely ruled out into this
evening.

..Weinman.. 11/21/2025

.PREV DISCUSSION... /ISSUED 1029 AM CST Fri Nov 21 2025/

...MS/AL/TN/KY...
A strengthening of deep-layer flow will occur regionally in tandem
with the eastward progression of a low-amplitude shortwave trough
from the Lower Missouri Valley toward the Lower Ohio River Valley
tonight, with height falls remaining limited south of the Tennessee
Valley.

The more organized/sustained scattered thunderstorms this afternoon
will probably remain focused within the warm conveyor from
south-central Mississippi into Alabama. On the south-southwest
periphery of these storms, there will be a gradual northeastward
expansion of the effective warm sector while destabilization will
still remain weaker with eastward extent. Mid-level lapse rates are
weak, suggesting most updrafts will struggle to intensify. However,
strong deep-layer shear and moderately strong low-level shear/SRH,
particularly within the aforementioned corridor, could support a
couple of rotating storms capable of a tornado or damaging wind.

The primary surface cold front will move into this region tonight,
with another round of showers and thunderstorms expected to uptick
this evening across the Mid-South including western Tennessee and
northern Mississippi. Low-level winds are expected to veer by this
time, reducing low-level shear/SRH. Nevertheless, a low risk of a
tornado and/or gusty winds will exist.

No watches are valid as of Fri Nov 21 19:47:01 UTC 2025.

No Mesoscale Discussions are in effect as of Fri Nov 21 19:47:01 UTC 2025.

SPC Day 2 Fire Weather Outlook

Day 2 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
0134 PM CST Fri Nov 21 2025

Valid 221200Z - 231200Z

...NO CRITICAL AREAS...

No changes are needed for the Day 2 Fire Weather Outlook. Broader
fire weather concerns remain absent across the contiguous U.S. as
recent rainfall, cooler temperatures and lack of alignment of
dry/breezy conditions with receptive fuels have mitigated overall
fire danger.

..Williams.. 11/21/2025

.PREV DISCUSSION... /ISSUED 1251 AM CST Fri Nov 21 2025/

...Synopsis...
No fire-weather concerns are anticipated Saturday. Much of the
Continental U.S. will experience surface high pressure, cooler
temperatures, and weak surface winds, combined with recent wetting
rainfall that has dampened remaining fuels.

...Please see www.spc.noaa.gov/fire for graphic product...

SPC 1930Z Day 3 Outlook

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0128 PM CST Fri Nov 21 2025

Valid 231200Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
WESTERN INTO CENTRAL TEXAS...

...SUMMARY...
Isolated severe thunderstorms are possible across portions of
northern Texas to the Rio Grande on Sunday. Large hail is the
primary threat.

...Synopsis...
A progressive upper pattern will prevail over the CONUS on Day
3/Sunday as multiple mid-level troughs progress across the
Northeast, the Plains states, and the Pacific Northwest,
respectively. At the surface, high pressure and static stability
will become established east of the MS River to the East Coast, and
over much of the Interior West, limiting thunderstorm potential over
these regions. However, the amplification of the central U.S.
mid-level trough will encourage surface lee troughing and subsequent
southerly moisture return across portions of the central and
southern Plains, where isolated to scattered thunderstorms are
likely. Strong flow aloft over TX will overspread a moist axis,
where adequate coinciding buoyancy and vertical wind shear will
support an isolated severe threat. Otherwise, a few lightning
flashes are possible along the Pacific Northwest coastline with the
passage of a mid-level trough and accompanying cooler temperatures
aloft.

...Portions of southwestern into central TX...
As the mid-level trough overspreads TX through the period, a
southerly low-level jet will develop, particularly after 00Z, when
850 mb southerly flow will exceed 35 kts. A relatively stable
boundary layer will remain in place Sunday through Sunday night.
However, atop this layer, seasonably rich moisture around 850 mb,
beneath 6.5-7.5 C/km mid-level lapse rates, will yield 1000-1500
J/kg of MUCAPE, which is adequate for supporting strong but elevated
thunderstorms. From late afternoon into the overnight hours,
increased isentropic lift above the stable boundary layer, driven by
the approaching mid-level trough, will promote an increase in
thunderstorms through the evening over western and central TX. The
southerly 35 kt low-level jet, overspread by 50-70 kt mid-level
southwesterlies from the upper trough, will yield elongated
hodographs and up to 50 kts of effective bulk shear. This shear, and
aforementioned MUCAPE, will support the potential for elevated
supercells late Sunday afternoon and overnight, with severe hail
possible.

..Squitieri.. 11/21/2025

SPC 1730Z Day 2 Outlook

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1127 AM CST Fri Nov 21 2025

Valid 221200Z - 231200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Isolated thunderstorms are possible from the Southwest into the
southern Plains and Southeast tomorrow (Saturday), though severe
thunderstorm potential appears low.

...Synopsis...
A broad mid-level trough, with multiple embedded impulses, will
progress across the eastern U.S. as upper ridging builds over the
Plains, and an upper low overspreads the Southwest tomorrow
(Saturday). With the evolution of this upper pattern, surface high
pressure and accompanying cooler, stable air will overspread most of
the central and northern CONUS, limiting thunderstorm potential.
From southeast TX to the coastal Carolinas, widely scattered
thunderstorm development is possible ahead of a surface cold front,
which will be ushered southeast by the aforementioned mid-level
trough, toward a seasonably moist low-level airmass. Thunderstorms
will also be possible across portions of the Desert Southwest into
western TX, beneath the progression of the upper low, which may
evolve into an upper wave through Saturday. Cooler temperatures
aloft will promote buoyancy (albeit scant) for thunderstorm
development.

...Southeast VA into central and eastern NC...
In roughly the 18-00Z period, isolated to widespread scattered
thunderstorm development is possible ahead of the cold front, aided
further by upper support with an overspreading embedded mid-level
impulse. Overlapping 60-70 kt 500 mb westerly flow atop 25+ kt
west-southwesterly 850 mb winds will yield elongated, straight
hodographs and 40+ kts of effective bulk shear. Through the day,
diurnal heating will support upper 60s/mid 70s F surface
temperatures amid 60+ F dewpoints. These low-level thermodynamic
conditions should yield around 500 J/kg MLCAPE via tall/thin
buoyancy profiles given modest tropospheric lapse rates. While gusty
conditions and perhaps some hail may accompany the stronger storms,
organized severe wind/hail seems unlikely, with severe probabilities
withheld for now.  

...Southern and central AZ into southwestern NM...
A nearly vertically stacked upper low (from roughly 850 mb on up)
will overspread AZ and NM through the period. A belt of stronger,
mostly unidirectional flow in the 850-500 mb layer will pivot around
the low and overspread portions of southern into central AZ and
southwestern NM in the 00-12Z time frame. This flow, resulting in
elongated hodographs (and 35-45 kts of effective bulk shear) will
coincide with 7.5-8 C/km mid-level lapse rates, supporting
multicells capable of at least small hail. Since these favorable
conditions will be overspreading an overnight (potentially stable)
boundary layer, MUCAPE should be thin, and only reach a few hundred
J/kg. As such, the current thinking is that buoyancy may be too
limited to support severe probabilities.

..Squitieri.. 11/21/2025

SPC Day 1 Fire Weather Outlook

Day 1 Fire Weather Outlook  
NWS Storm Prediction Center Norman OK
1033 AM CST Fri Nov 21 2025

Valid 211700Z - 221200Z

...NO CRITICAL AREAS...

No changes for the Day 1 Update as fire weather concerns remain low
across the CONUS. See previous forecast discussion for additional
information.

..Williams.. 11/21/2025

.PREV DISCUSSION... /ISSUED 1251 AM CST Fri Nov 21 2025/

...Synopsis...
No fire-weather concerns are anticipated on Friday. Cooler
temperatures and weak surface winds, along with recent wetting
rainfall across much of the U.S. that has dampened remaining dry
fuels, will serve to mitigate any risk of wildfire ignition and
spread.

...Please see www.spc.noaa.gov/fire for graphic product...

SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1029 AM CST Fri Nov 21 2025

Valid 211630Z - 221200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
MS/AL/TN/KY...

...SUMMARY...
Isolated strong to severe storms are possible today and tonight
across parts of Mississippi and Tennessee into western and northern
Alabama and possibly southern Kentucky.

...MS/AL/TN/KY...
A strengthening of deep-layer flow will occur regionally in tandem
with the eastward progression of a low-amplitude shortwave trough
from the Lower Missouri Valley toward the Lower Ohio River Valley
tonight, with height falls remaining limited south of the Tennessee
Valley.

The more organized/sustained scattered thunderstorms this afternoon
will probably remain focused within the warm conveyor from
south-central Mississippi into Alabama. On the south-southwest
periphery of these storms, there will be a gradual northeastward
expansion of the effective warm sector while destabilization will
still remain weaker with eastward extent. Mid-level lapse rates are
weak, suggesting most updrafts will struggle to intensify. However,
strong deep-layer shear and moderately strong low-level shear/SRH,
particularly within the aforementioned corridor, could support a
couple of rotating storms capable of a tornado or damaging wind.

The primary surface cold front will move into this region tonight,
with another round of showers and thunderstorms expected to uptick
this evening across the Mid-South including western Tennessee and
northern Mississippi. Low-level winds are expected to veer by this
time, reducing low-level shear/SRH. Nevertheless, a low risk of a
tornado and/or gusty winds will exist.

..Guyer/Kerr.. 11/21/2025