SPC 1630Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1000 AM CST Mon Dec 01 2025

Valid 011630Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ARE POSSIBLE
LATE TONIGHT ACROSS COASTAL PORTIONS OF ALABAMA AND THE FLORIDA
PANHANDLE...

...SUMMARY...
Isolated severe storms are possible across coastal portions of
Alabama and the Florida Panhandle late tonight into early Tuesday
morning.

...Gulf Coast...

A large-scale upper trough oriented from the Upper Midwest to the
southern High Plains late this morning will continue eastward
through the period, becoming positioned from the Great Lakes to the
Lower MS Valley by Tuesday morning. Another weaker mid/upper
shortwave located over the northwest Gulf will lift northeast across
the central/eastern Gulf coast vicinity while merging with the
aforementioned synoptic-scale trough. As this occurs, a broad area
of stronger south/southwesterly low to midlevel flow will overspread
the Gulf coast/Southeast. This warm advection regime will allow low
to mid 60s F dewpoints to impinge on immediate coastal areas in AL
and the FL Panhandle ahead of an eastward advancing cold front late
tonight. 

Within the warm frontal zone, modest surface-based instability
should develop after 06z. Forecast soundings indicate supercell wind
profiles will be present. However, poor lapse rates and SBCAPE
generally less than 750 J/kg will limit updraft intensity. Storms
moving inland from the Gulf also will have limited area before
becoming elevated to the cool side of the warm front. Nevertheless,
transient supercells could produce a tornado or two, and/or
localized strong gusts, early Tuesday morning. The risk may continue
north and east into portions of northern FL on Tuesday morning at
the beginning of the Day 2 period (see Day 2 Convective Outlook for
more details).

Additional isolated elevated thunderstorms will be possible from the
TX coastal Plain into portions of the Lower MS Valley today. This
activity is occurring within persistent, broad large-scale ascent
and midlevel warm advection atop a cooler/drier boundary-layer.
Severe storms are not expected with this activity.

...Coastal Carolinas...

A prior cold frontal passage and cold air damming across the
Piedmont will generally keep 60s F dewpoints offshore through the
period. Some guidance does bring a sliver of better boundary layer
moisture along the immediate coast/Outer Banks vicinity the last
couple hours of the period. However, any appreciable instability and
stronger convection is expected to remain offshore through 12z
Tuesday.

..Leitman.. 12/01/2025

No watches are valid as of Mon Dec 1 16:05:02 UTC 2025.

MD 2242 CONCERNING WINTER MIXED PRECIPITATION FOR NORTHEAST OK...WESTERN/CENTRAL AR...FAR SOUTHWEST MO


Mesoscale Discussion 2242
NWS Storm Prediction Center Norman OK
0637 AM CST Mon Dec 01 2025

Areas affected...Northeast OK...western/central AR...far southwest
MO

Concerning...Winter mixed precipitation 

Valid 011237Z - 011700Z

SUMMARY...Freezing rain may increase across parts of central
Arkansas this morning, while light mixed precipitation will continue
to spread from northeast Oklahoma into northwest Arkansas and far
southwest Missouri.

DISCUSSION...Mixed precipitation (mainly in the form of shallow
convective showers) has been spreading east-northeastward across
central/eastern OK this morning. The 00Z OUN, 06Z LMN, and 12Z FWD
soundings, along with recent objective mesoanalyses, suggest that a
temperature inversion above 700 mb is limiting the depth of the
convective showers, while dryness below 800 mb initially limited
precipitation rates. However, the regenerative nature of this
precipitation has resulted in evaporative moistening and cooling of
the column, allowing for at least light accumulations of
precipitation at the ground. Some icing has been noted in the OKC
area, and light ice accretion and/or sleet accumulation may spread
east-northeastward from northeast OK into northwest AR and far
southwest MO. Some snow may mix with the precipitation in this area,
though with the primary ascent and saturation occurring generally
below the dendritic growth zone, a tendency toward sleet or freezing
rain may persist in these areas as well. 

Farther south, stronger buoyancy (as observed in the 12Z FWD
sounding with MUCAPE above 100 J/kg) may support somewhat heavier
precipitation rates from southwest into central AR later this
morning, within a persistent low-level warm-advection regime. While
low-level temperatures are more marginal compared to areas farther
north, evaporative cooling and relatively dry/cold surface
trajectories from the northeast may allow for some ice accretion,
especially on elevated surfaces. A transition to primarily rain may
occur from southwest to northeast by late morning, due to continued
warm advection and muted diurnal heating.

..Dean.. 12/01/2025

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

ATTN...WFO...LZK...SGF...SHV...TSA...

LAT...LON   35399566 35989597 36629598 36859458 36509267 35449188
            34449201 33789247 33749316 34059431 34529443 35189452
            35399566

SPC 1300Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0645 AM CST Mon Dec 01 2025

Valid 011300Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS COASTAL
PORTIONS OF ALABAMA AND THE FLORIDA PANHANDLE...

...SUMMARY...
Isolated severe storms are possible across coastal portions of
Alabama and the Florida Panhandle late tonight into early Tuesday
morning.

...Synopsis...
Early-morning satellite imagery shows a well-defined shortwave
trough moving eastward through the Four Corners vicinity, within the
base of a larger upper trough that extends from the Upper MS Valley
through AZ. This shortwave is forecast to pivot eastward and then
northeastward throughout the period, moving across the
southern/central High Plains, OK/KS, and the Mid-South before ending
the period over the upper OH Valley. A strong mid-level jetlet (i.e.
90 kt at 500-mb) is anticipated within the base of this shortwave,
with a more expansive strengthening of the mid-level southwesterly
flow anticipated across much of area preceding the wave (i.e. from
the mid/lower MS Valley into much of the eastern CONUS). 

Even with the strengthening wind fields aloft and large-scale ascent
attendant to this deepening wave, the limited time since the
previous frontal intrusion will keep any low-level moisture return
confined largely to the immediate Gulf Coast. Even so, a few
elevated thunderstorms are possible from this morning into the
afternoon across the TX Gulf Coast, with much of this activity
supported by ascent and warm-air advection attendant to a more
subtle, lower-amplitude shortwave currently moving into south TX.
Phasing of this lower-amplitude shortwave with the stronger
shortwave farther north will support a more expansive strengthening
of the low-level south-southwesterly flow late in the period. This
phasing will also contribute to a deepening of a surface low
progressing northeastward along a warm front moving northward into
the FL Panhandle. Some severe potential is possible late tonight
into early tomorrow as this surface low interacts with an
increasingly moist and buoyant airmass over the FL Panhandle.  

...Coastal AL and FL Panhandle...
Most guidance brings mid 60s dewpoints into immediate coastal region
of AL and the FL Panhandle during the last 4 hours of the period
(08Z-12Z Tuesday), just ahead of the surface low. This increasing
low-level moisture should erode any low-level convective inhibition
and result in an airmass supportive of surface-based thunderstorms.
Buoyancy will be modest, but still sufficient, for deep updrafts,
amid veering low-level wind profiles and robust mid-level flow. As a
result, a few supercells could be maintained or develop as the warm
sector convection moves ashore from coastal AL across the FL
Panhandle. Primary risks with these storms are a brief tornado
and/or localized damaging gusts over the immediate coast. This
threat will continue past 12Z Tuesday into northern FL, which is
discussed in the Day 2 Convective Outlook.

...Coastal Carolinas...
Strengthening low-level flow will contribute to increasing warm-air
advection showers and thunderstorms late Monday through early
Tuesday. Consensus within the guidance keeps the higher low-level
moisture just offshore, and the majority of this activity will be
elevated atop a strong low-level inversion. This should temper the
overall severe potential. Immediate coastal regions south of MHX may
see higher dewpoints right at the end of the period, but any
stronger storms are still expected to remain offshore.

..Mosier/Dean.. 12/01/2025