ACUS02 KWNS 241727

SWODY2

SPC AC 241725



Day 2 Convective Outlook  

NWS Storm Prediction Center Norman OK

1225 PM CDT Fri Oct 24 2025



Valid 251200Z - 261200Z



...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF

CENTRAL TEXAS INTO THE SABINE RIVER VALLEY...



...SUMMARY...

Scattered severe thunderstorms are possible tomorrow (Saturday),

across Texas into the Sabine River Valley. All severe hazards are

possible. A couple of severe gusts or a brief tornado are also

possible over parts of the Pacific Northwest.



...Synopsis...

A mid-level trough will traverse the southern U.S., while an upper

troughs ejects into the Atlantic and a more pronounced, larger scale

upper trough impinges on the Interior West tomorrow (Saturday).

Ahead of the southern U.S. upper trough, low-level troughing will

encourage southerly return flow from the Gulf, resulting in airmass

modification amid a warm-air/moisture advection regime. As upper

support from the aforementioned trough encourages deep-layer ascent

amid this moist airmass, thunderstorms will continue to develop

and/or persist across Texas into the Sabine River Valley. Given

adequate vertical wind shear accompanying this moist low-level

airmass, multiple rounds of strong to potentially severe storms are

likely. Strong flow aloft and associated vertical wind shear will

overspread the Pacific Northwest, amid scant buoyancy, to support

low-topped but potentially strong storms.



...Portions of Texas into the Sabine River Valley...

Thunderstorms (perhaps in the form of an MCS), should be ongoing at

the start of the period across TX, remnant from the Day 1 period.

These storms will be preceded by a moist low-level airmass (i.e. at

least mid to upper 60s F dewpoints), yielding 1000-2000 J/kg MLCAPE

given modest mid-level lapse rates. A 35-45 kt southerly low-level

jet will already be in place over eastern TX toward the Sabine River

Valley, which will promote sizeable, curved low-level hodographs. As

such, multicells and/or supercells embedded within this MCS will

support all hazards during the morning hours, with the best chance

for isolated tornadoes being with supercells that can remain

discrete. These storms will approach the Gulf shoreline by around

Noon, and are poised to weaken in the process.



The progression of the earlier storms complicates severe potential

for the central TX into the Sabine River Valley later Saturday into

Saturday night. This is when the primary wave will overspread the

region, coincident with strengthening and some eastward shift of the

low-level jet. At least one additional, pronounced round of

thunderstorms is expected to develop across central TX during the

afternoon, and progress across LA during the evening/overnight

hours. Should adequate airmass destabilization occur behind the

preceding round of storms, deep-layer and low-level shear will be

adequate to support supercell structures and subsequent upscale

growth into a QLCS. In addition to large hail (especially over

central TX), sizeable and curved low-level hodographs will support

tornado potential. The best chance for tornadoes with the second

round of storms will be over LA late Saturday, when the storms

traverse the low-level jet axis.



...Portions of the Pacific Northwest...

As broad and pronounced mid-level trough overspreads the Pacific

Northwest through the morning to late afternoon hours tomorrow

(Saturday), 80-100 kts of westerly mid-level flow will overspread

the region. Some forecast soundings indicate 50 kt westerly flow

extending as low as 700 mb in altitude, suggesting that little

mechanical downward momentum transport is needed to support strong

to potentially severe wind gusts. Strong deep-layer ascent, amid

scant but possibly adequate buoyancy, will encourage the development

of at least one (possibly multiple) low-topped convective bands.

These bands (regardless of lightning potential) may produce a couple

of severe gusts, especially over higher terrain, warranting the

introduction of Category 1/Marginal risk probabilities. Low-end

tornado probabilities have also been added to the OR coastline,

where a few low-topped supercells may promote a landfalling brief

tornado.



..Squitieri.. 10/24/2025



$$