ACUS01 KWNS 221231
SWODY1
SPC AC 221230

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0630 AM CST Sat Feb 22 2025

Valid 221300Z - 231200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Scattered thunderstorms remain possible from the middle and upper
Texas Coast toward the Sabine Valley late today and overnight. A few
storms could produce some small hail.

...Synopsis...
Recent satellite imagery shows a pair of shortwave troughs
progressing through the southern stream, with the lead wave moving
through the Ozark Plateau and the second wave dropping through AZ
towards northern Mexico. The lead wave is forecast to continue
eastward, moving quickly through the TN Valley and central
Appalachians before moving off the Carolina coast. The second
shortwave is expected to pivot more eastward as it moves along the
US/Mexico border before continuing across the southern High Plains
and reaching central TX by early Sunday morning.

Farther northwest, a shortwave trough and attendant strong mid-level
flow will likely reach the Pacific Northwest coast late
tonight/early tomorrow. Some deeper convective cores are possible
within the frontal band preceding this shortwave, a few of which
could be deep enough to produce occasional lightning flashes.

...Upper TX Coast into Southwest LA...
Recent surface analysis shows that the cold and dry airmass remains
firmly in place across the southern Plains, with surface ridging
anchored over AR maintaining offshore flow. This airmass is expected
to remain largely in place, with only modest modification throughout
the day. Much of the guidance keeps surface temperatures in the 40s
along the TX and LA coasts throughout the period.

Low to mid-level southwesterly flow is expected to increase as the
second shortwave trough mentioned in the synopsis approaches the
region. Cold mid-level temperatures will accompany this shortwave as
well. As a result, despite persistent surface stability, some
elevated buoyancy is expected, with showers and embedded
thunderstorms anticipated from the early afternoon through Sunday
morning. The general expectation is for thunderstorm coverage to
maximize after 06Z Sunday as the shortwave moves through TX, with an
associated increase in large-scale ascent and decrease of the
mid-level temperatures. Fairly strong shear within the cloud-bearing
layer will overlap this modest thermodynamic environment, resulting
in the potential for a few strong, more persistent, and organized
updrafts embedded within the large precipitation shield. Some of
these storms may become strong enough to produce hail, but most
should be sub-severe (i.e. less than 1" in diameter), and the
overall severe coverage is still expected to be below 5%.

..Mosier/Grams.. 02/22/2025

$$
--- SBBSecho 3.20-Linux
 * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (618:250/1)