179 
ACUS01 KWNS 260454
SWODY1
SPC AC 260452

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1152 PM CDT Sat Oct 25 2025

Valid 261200Z - 271200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TODAY THROUGH
TONIGHT ACROSS PARTS OF THE CENTRAL AND EASTERN GULF COASTAL
PLAIN...

...SUMMARY...
Strong thunderstorms may impact the north central into eastern Gulf
coastal vicinity this morning, then mainly this evening into early
Monday, accompanied by at least some risk for severe weather.

...Discussion...
Models indicate that strong, generally zonal mid/upper flow will be
maintained across the mid-latitude Pacific into western North
America through this period.  As one significant short wave trough
emerging from this regime progresses northeast of the Canadian
Prairies toward the northeastern Canadian Arctic latitudes, another
is rapidly pivoting across the northern U.S. Rockies toward the
Canadian Prairies.  

Downstream, amplification of mid/upper flow is already well
underway, including building ridging across parts of the Upper
Midwest through Ontario and the southern Hudson/James Bay vicinity,
and consolidating/digging troughing near the northern Atlantic
coast.  Models suggest that a closed cyclonic circulation may evolve
within the troughing offshore of the New England coast today through
tonight, while a short-lived anticyclonic circulation evolves within
the ridge across  the upper Great Lakes vicinity.  To the south of
the ridge, a low initially centered over the south central Great
Plains may slowly reform eastward across the Ozark Plateau/Mid
South, with broadly cyclonic flow to its south overspreading the
northern Gulf coast vicinity.

Beneath the confluent eastern North American regime, expansive cool
surface ridging is likely to persist, and maintain considerable
influence as far south and west as the Gulf Coast states into
southern Great Plains.  However, relatively lower surface pressure
may shift east of the southern Great Plains through the lower
Mississippi Valley, with perhaps a weak embedded low developing
across and east-southeastward offshore of the southeastern Louisiana
coastal plain later today through tonight.

...Northern Gulf coast...
In association with the evolving pattern, seasonably moist,
potentially unstable boundary-layer air is forecast to become
largely confined to areas near and offshore of coastal areas.  A
couple of strong storms may linger from the overnight into early
morning across parts of southern Mississippi and southeastern
Louisiana.  However, the latest convection allowing model output
suggests that vigorous thunderstorm development, with at least some
potential for evolving embedded mesoscale cyclonic circulations,
will mostly accompany the developing weak surface low.  The
environment most conducive to this may evolve this evening into
early Monday near and offshore of the southern Alabama and western
Florida Panhandle coast.

..Kerr/Wendt.. 10/26/2025

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20251026T0454.txt



690 
ACUS01 KWNS 260052
SWODY1
SPC AC 260051

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0751 PM CDT Sat Oct 25 2025

Valid 260100Z - 261200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TONIGHT ACROSS
PARTS OF SOUTHEAST TEXAS...CENTRAL AND SOUTHERN LOUISIANA AND
ADJACENT SOUTHWESTERN MISSISSIPPI...

...SUMMARY...
Potential for severe thunderstorms may still increase overnight
across parts of central and southern Louisiana, and perhaps as early
as late evening across parts of southeastern Texas coastal areas.

...01Z Update...
As a notable short wave perturbation pivots around the southern
through eastern periphery of a mid/upper low now centered over the
south central Great Plains, modest strengthening of initially weak
lower/mid-tropospheric wind fields are forecast across the northwest
Gulf coast through lower Mississippi Valley overnight.  It appears
that this may include south to southwesterly flow increasing in
excess of 30 kts in the 850-700 mb layer across the Louisiana coast
through southwestern Mississippi after 06Z.  As this occurs, forcing
for ascent, supported by at least modest low-level warm advection
beneath an increasingly divergent upper flow field overspreading the
region, may contribute to increasing thunderstorm development.  In
the presence of strong deep-layer shear and a moist low-level
environment characterized by CAPE on the order of 1000-2000+ J/kg,
organized convection, perhaps including supercells and an upscale
growing cluster or two, may be accompanied by a risk for severe
hail, potentially damaging wind gusts and a couple of tornadoes.

..Kerr.. 10/26/2025

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20251026T0052.txt



215 
ACUS01 KWNS 251242
SWODY1
SPC AC 251241

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0741 AM CDT Sat Oct 25 2025

Valid 251300Z - 261200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
TEXAS AND LOUISIANA...

...SUMMARY...
Scattered severe thunderstorms are possible today into tonight from
central Texas eastward into the lower Mississippi Valley.

...TX-LA...
Water-vapor imagery shows a mid- to upper-level low over the
southern High Plains and it is forecast to move east across much of
OK by early Sunday morning.  Strong cyclonic 500-mb flow (40-60 kt)
will move through the base of the larger scale trough over TX and
eventually moving into the lower MS Valley.  An ongoing MCS across
southwestern LA and the northwest Gulf of America will likely
progress eastward across southern LA through early afternoon.  An
isolated risk for damaging gusts (55-65 mph) and a brief tornado may
continue east but be increasingly confined to the coastal parishes
as the squall line's eastward movement outpaces appreciable inland
destabilization.  

High uncertainty is apparent farther west across central into east
and coastal portions of TX.  Earlier shower/thunderstorm activity
across much of the mid and upper coastal plain of TX has rendered
substantial convective overturning of the airmass from the coastal
plain northwestward towards the I-35 corridor north of a composite
outflow boundary.  Models vary regarding destabilization and this
signal in model data is congruent with forecaster experience in
placing low confidence in potential storm evolution later this
afternoon into the evening across central and east TX.  Nonetheless,
there will probably exist a window of opportunity for diurnal
destabilization arcing around the south and west portions of the
mesoscale surface high.  Some forecast soundings show moderate
instability in the presence of strong mid to high-level westerly
flow---supporting supercells and storm organization with
accompanying potential for damaging gusts.  

Have adjusted the northern bounds of tornado probabilities farther
south in closer proximity to richer moisture, and removed 15-percent
hail probabilities across southeast TX and LA where lapse rates will
likely remain stunted through early Sunday morning.  The tornado
risk correspondingly will tend to favor any supercell development in
proximity to richer moisture and mesovortex structures within parent
QLCSs, but low confidence exists regarding this forecast given
aforementioned convective-related concerns.  

...Pacific Northwest...
A mid-level trough, and an associated plume of moisture, will move
eastward into the Pacific Northwest today.  Strong large-scale
ascent will be favorable for thunderstorm development along the
coast of Washington and Oregon.  A brief tornado risk could develop
near the immediate coast and marginally severe wind gusts will be
possible as cells move inland.  Farther east into parts of southeast
Washington and far northeast Oregon, thunderstorm development will
be possible late this afternoon with perhaps isolated severe gusts
associated with the stronger thunderstorms.

..Smith/Weinman.. 10/25/2025

$$


File: /home/ldm/var/data/BY_SOURCE/KWNS/ACUS01/20251025T1242.txt