ACUS01 KWNS 250601

SWODY1

SPC AC 250600



Day 1 Convective Outlook  

NWS Storm Prediction Center Norman OK

0100 AM CDT Sat Oct 25 2025



Valid 251200Z - 261200Z



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

TEXAS AND LOUISIANA...



...SUMMARY...

Scattered severe thunderstorms with a tornado threat, large hail and

severe wind gusts are possible this afternoon and evening from

central Texas eastward into the lower Mississippi Valley. Very large

hail will be possible across parts of the middle Texas Coastal

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

over parts of the Pacific Northwest.



...Western Gulf States...

A mid-level low will move eastward into the southern Plains today,

as an associated jet streak translates eastward through the base of

the system. Ahead of the system, diffluent southwesterly mid-level

flow will be in place over much of the western Gulf Coast states. A

linear MCS will be ongoing at the start of the period across

southeast Texas. A tornado and wind-damage threat will exist with

the more intense segments of the line. The severe threat will

continue to move eastward across central and southern Louisiana this

morning, reaching the New Orleans area by early afternoon.



Although the line will stabilize the airmass over much of Louisiana,

moderate instability is expected to redevelop in its wake over the

Texas Coastal Plain, where MLCAPE is forecast to reach the 1500 to

2500 J/kg range by afternoon. Along the western edge of the stronger

instability, low-level convergence will aid scattered convective

initiation this afternoon across eastern parts of the Texas Hill

Country and over the middle Texas Coastal Plain. RAP forecast

soundings late this afternoon from San Antonio to Houston have 0-6

km shear around 50 knots with 700-500 mb lapse rates near 7 C/km.

This should support supercells with large hail. The more intense

supercells could produce hailstones greater than 2 inches in

diameter.



In addition, 0-3 km storm relative-helicity is forecast to be in the

200 to 250 m2/s2 range over the middle Texas Coastal Plain

suggesting that a few tornadoes will be possible. A potential will

exist for a strong tornado, although this remains uncertain. The

storms are expected to congeal into a linear convective system by

early evening. A potential for damaging wind gusts will exist along

the leading edge of the line, with the threat continuing into the

early overnight period, along and near the coast of southern

Louisiana.



...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 and marginally severe wind

gusts will be possible as cells move inland near the coast. Further

east into parts of southeast Washington and far northeast Oregon,

thunderstorm development will be possible late this afternoon as a

low-level jet streak moves across the region. In this area, lapse

rates will be steep and flow will be strong suggesting that an

isolated wind-damage threat will be possible.



..Broyles/Wendt.. 10/25/2025



$$