140 
ACUS01 KWNS 011232
SWODY1
SPC AC 011230

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0630 AM CST Sun Mar 01 2026

Valid 011300Z - 021200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTH FLORIDA AND OKLAHOMA...

...SUMMARY...
Isolated severe thunderstorms capable of producing occasional large
hail and damaging winds may occur this afternoon and evening across
parts of south Florida and Oklahoma.

...South Florida...
Recent water vapor satellite imagery shows a weak/low-amplitude
mid-level shortwave trough over the northeast Gulf. This feature
will track east-southeastward today over the FL Peninsula. Modest
ascent associated with the shortwave trough should aid in isolated
to widely scattered thunderstorms developing this afternoon across
parts of south FL in the vicinity of a decaying front, and along the
Atlantic Coast sea breeze. Around 1000-1500 J/kg of MLCAPE may
develop across this region by peak afternoon heating, with
seasonably cool mid-level temperatures present (around -12 to -13C
at 500 mb). While low-level winds are expected to remain weak, some
enhancement to the west-northwesterly mid-level flow attendant to
the approaching shortwave trough should provide marginal deep-layer
shear to foster modest thunderstorm organization. Consensus of
recent high-resolution guidance suggests that at least isolated
thunderstorms may form by 18-22Z south of the front and along
various sea breezes while posing some threat for severe hail and
occasional damaging winds. Have therefore included a Marginal Risk
for parts of south FL with this update.

...Oklahoma...
With large-scale upper troughing persisting over the eastern CONUS
today, a weak shortwave trough will advance east-southeastward from
the central High Plains this morning towards OK by early evening. A
surface cold front is progged to decelerate and eventually stall
along the I-40 corridor in OK, with modest boundary layer moisture
present to its south. A narrow corridor of around 500-1000 J/kg of
MUCAPE should develop by late afternoon/early evening along/near the
front, aided by daytime heating and modestly steepened mid-level
lapse rates. There is still a fair amount of uncertainty regarding
convective initiation and overall thunderstorm coverage later today
across OK, mainly owing to only weak large-scale ascent attendant to
the low-amplitude shortwave trough and somewhat modest low-level
moisture. Even so, the presence of elongated/nearly straight
hodographs at mid/upper levels and related strong deep-layer shear
suggest some potential for large hail and locally damaging winds if
any robust updrafts can form and be sustained near the front late
this afternoon and continuing into the evening. A focused Marginal
Risk has been introduced this update where the best chance for
isolated/sustained convection is apparent.

...Northern California...
Large-scale ascent will overspread northern CA and vicinity ahead of
an upper low that will approach the CA Coast by this evening.
Gradually cooling mid-level temperatures and filtered diurnal
heating of a modestly moist low-level airmass should support the
development of weak instability across this region through the
afternoon and evening. Isolated thunderstorms should develop, with
the more robust updrafts possibly capable of producing small hail
and gusty winds. This activity is expected to remain below severe
levels owing to the weak instability forecast.

..Gleason/Bentley.. 03/01/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260301T1232.txt



660 
ACUS01 KWNS 010537
SWODY1
SPC AC 010536

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1136 PM CST Sat Feb 28 2026

Valid 011200Z - 021200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms will be possible across parts of south Florida, the
southern and central Plains, and in northern California region this
afternoon and evening.

...Discussion...

South Florida: Large-scale pattern will not change appreciably
during the upcoming day1 period as broad upper troughing holds
across the eastern CONUS with ridging expected over the Great Basin.
Cool midlevel temperatures will overspread the FL Peninsula such
that modest boundary-layer heating will contribute to sufficient
instability for deep convection. Weak height rises and easterly
component to low-level flow are not particularly favorable for
severe thunderstorms, though a few robust updrafts could generate
gusty winds or small hail across the southeastern FL Peninsula.

Southern/Central Plains: Sharp cold front will settle south across
OK/TX Panhandle during the day as the center of the surface
anticyclone shifts into the Great Lakes. Modest boundary-layer
heating will be noted ahead of this wind shift across the TX South
Plains into southwestern OK which will result in convective
temperatures being breached by 22z as temperatures rise into the
lower 80s. PW values are not that moist across the southern Plains,
but weak low-level warm advection is expected atop the cold boundary
layer north of the front. Elevated convection should develop across
this region but weak buoyancy does not appear adequate for severe
hail with the strongest updrafts.

Northern California region: Modest midlevel height falls will spread
across northern CA ahead of a notable upper low that will approach
the coast by 02/00z. Left-exit region of 500mb jet is expected to
aid ascent across northern CA, and more than adequate instability
should materialize for thunderstorm development. Forecast soundings
exhibit around 500 J/kg MLCAPE with cool midlevel temperatures and
steep lapse rates. The most robust updrafts could generate small
hail, but this activity is expected to remain below severe levels.

..Darrow/Lyons.. 03/01/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260301T0537.txt



001 
ACUS01 KWNS 010042
SWODY1
SPC AC 010041

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0641 PM CST Sat Feb 28 2026

Valid 010100Z - 011200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorms are not forecast tonight.

...01z Update...

Weak surface front is gradually advancing south across the southern
FL Peninsula early this evening. Scattered convection continues near
the south FL Atlantic coast, as deep westerly flow has shunted
better low-level convergence into this portion of the peninsula. 00z
sounding from MFL exhibited substantial instability, but latest
radar/lightning trends suggest updrafts have weakened considerably.
Primary threat for thunderstorms appears to have shifted offshore,
especially as boundary layer continues to cool over the next few
hours.

00z sounding from OUN exhibited around 500 J/kg MLCAPE with a deep
boundary layer and only modest PW. Scattered weak convection is
mostly concentrated over the Ozark region, and this activity only
has isolated lightning noted with it. Given the weak 850mb flow it
appears the risk for thunderstorms will continue to wane this
evening.

Scattered thunderstorms have developed ahead of a short-wave trough
approaching northern CA. This feature will deamplify as it ejects
into the northern Great Basin later this evening. Lightning may
accompany the stronger updrafts given the large-scale support.

..Darrow.. 03/01/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260301T0042.txt



563 
ACUS01 KWNS 281947
SWODY1
SPC AC 281945

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0145 PM CST Sat Feb 28 2026

Valid 282000Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
CENTRAL AND SOUTH FLORIDA...

...SUMMARY...
Isolated strong to severe thunderstorms may occur across parts of
the central/southern Florida Peninsula this afternoon and evening.

...20Z Update...
Only minor changes to the general thunderstorm forecast in North
Florida were made base on current observations. Mid-level ascent is
entering the northeastern Gulf per visible/water-vapor satellite.
This should continue to promote potential for additional
thunderstorms within the central and southern Florida Peninsula. See
the previous discussion for additional details.

..Wendt.. 02/28/2026

.PREV DISCUSSION... /ISSUED 1012 AM CST Sat Feb 28 2026/

...Central/Southern Florida Peninsula...
Late morning surface analysis places a cold front near the I-4
corridor across the central portion of the Peninsula, with upper 60s
to lower 70s dewpoints south of the boundary.  A mid-level vorticity
maximum over MS/AL this morning is forecast to continue
east-southeastward through the base of a larger-scale eastern US
trough and eventually reach the Gulf Stream east of GA and
southwestward to the southern 1/3 of the Peninsula by early Sunday
morning.  As this impulse progresses towards the region, the
aforementioned front will slowly move south.  This boundary, a
residual outflow boundary, and an east-coast sea breeze will help
focus thunderstorm development and a potential severe risk this
afternoon.  Ample heating of the moist boundary layer beneath a weak
cap, which will continue to erode by early to mid afternoon, will
result in 1500-2000 J/kg MLCAPE.  Low-level flow will likely remain
veered and relatively weak, but 30+ kt shear in the 700-300 mb layer
will support some updraft organization.  Scattered thunderstorms are
forecast to develop in the 18-20z period with a some of the stronger
storms potentially being capable of 55-65 mph gusts and 1 to 1.75
inch diameter hail.  Short-term CAM guidance suggests the most
concentrated corridor for severe may extend from the north side of
Lake Okeechobee, where an agitated cumulus field is developing along
the diffuse outflow boundary, southward into Broward/Palm Beach
counties.  Convection is forecast to eventually move east into the
Atlantic this evening with the severe risk diminishing.

...Oklahoma...
Weak MUCAPE should develop by this afternoon/early evening across
parts of OK near a surface trough.  A low-amplitude shortwave trough
embedded within broad cyclonic flow over the central/eastern CONUS
may support isolated thunderstorm development across this area in
tandem with peak afternoon heating. Instability should remain too
weak to support an organized severe threat with this activity,
although locally strong/gusty winds and small hail appear possible
given steepened low-level lapse rates and favorably strong
deep-layer shear.

...Northern California...
A mid-level shortwave trough will move east-northeastward today
across northern CA and vicinity. Cool temperatures aloft associated
with this shortwave trough combined with generally 40 to mid 50s
surface dewpoints and filtered daytime heating should promote around
500-750 J/kg of MUCAPE over this region by mid to late afternoon. 
While a couple of stronger thunderstorms may form across this area,
the overall severe threat should tend to be limited by the weak
instability.

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260228T1947.txt



328 
ACUS01 KWNS 281613
SWODY1
SPC AC 281612

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1012 AM CST Sat Feb 28 2026

Valid 281630Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS CROSS PARTS OF
THE CENTRAL/SOUTHERN FLORIDA PENINSULA...

...SUMMARY...
Isolated strong to severe thunderstorms may occur across parts of
the central/southern Florida Peninsula this afternoon and evening.

...Central/Southern Florida Peninsula...
Late morning surface analysis places a cold front near the I-4
corridor across the central portion of the Peninsula, with upper 60s
to lower 70s dewpoints south of the boundary.  A mid-level vorticity
maximum over MS/AL this morning is forecast to continue
east-southeastward through the base of a larger-scale eastern US
trough and eventually reach the Gulf Stream east of GA and
southwestward to the southern 1/3 of the Peninsula by early Sunday
morning.  As this impulse progresses towards the region, the
aforementioned front will slowly move south.  This boundary, a
residual outflow boundary, and an east-coast sea breeze will help
focus thunderstorm development and a potential severe risk this
afternoon.  Ample heating of the moist boundary layer beneath a weak
cap, which will continue to erode by early to mid afternoon, will
result in 1500-2000 J/kg MLCAPE.  Low-level flow will likely remain
veered and relatively weak, but 30+ kt shear in the 700-300 mb layer
will support some updraft organization.  Scattered thunderstorms are
forecast to develop in the 18-20z period with a some of the stronger
storms potentially being capable of 55-65 mph gusts and 1 to 1.75
inch diameter hail.  Short-term CAM guidance suggests the most
concentrated corridor for severe may extend from the north side of
Lake Okeechobee, where an agitated cumulus field is developing along
the diffuse outflow boundary, southward into Broward/Palm Beach
counties.  Convection is forecast to eventually move east into the
Atlantic this evening with the severe risk diminishing.

...Oklahoma...
Weak MUCAPE should develop by this afternoon/early evening across
parts of OK near a surface trough.  A low-amplitude shortwave trough
embedded within broad cyclonic flow over the central/eastern CONUS
may support isolated thunderstorm development across this area in
tandem with peak afternoon heating. Instability should remain too
weak to support an organized severe threat with this activity,
although locally strong/gusty winds and small hail appear possible
given steepened low-level lapse rates and favorably strong
deep-layer shear.

...Northern California...
A mid-level shortwave trough will move east-northeastward today
across northern CA and vicinity. Cool temperatures aloft associated
with this shortwave trough combined with generally 40 to mid 50s
surface dewpoints and filtered daytime heating should promote around
500-750 J/kg of MUCAPE over this region by mid to late afternoon. 
While a couple of stronger thunderstorms may form across this area,
the overall severe threat should tend to be limited by the weak
instability.

..Smith/Leitman.. 02/28/2026

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20260228T1613.txt