Valid 212000Z – 221200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
TEXAS TO THE MIDDLE TEXAS COAST…
Isolated large hail will be possible this afternoon and evening from
central Texas toward the middle Texas coast.
Several elevated storms continue to form over central TX toward the
middle TX coast, where a developing southerly low-level jet ahead of
the upper wave will maintain lift through evening. Sufficiently cool
temperatures aloft, instability and effective shear will maintain a
threat of marginal hail today.
.PREV DISCUSSION… /ISSUED 1103 AM CDT Sat Mar 21 2020/
…Southern Plains through tonight…
Aside from the potential for isolated lightning flashes along a
slow-moving front near the southeast Atlantic coast, and sporadic
flashes from the southern Rockies to the northern Great Basin, the
primary thunderstorm threat area through tonight will be across the
southern Plains. In advance of a southern stream shortwave trough
now over the lower CO River Valley, a warm advection regime is
already underway across south central TX. This warm advection
regime will support an expansion of elevated convection northward
and northeastward through the day, with convection expected into OK
and east TX by tonight.
MUCAPE near 1000 J/kg (rooted above 850 mb) along the north edge of
the steeper midlevel lapse rates, and effective bulk shear near 50
kt with relatively straight hodographs, has supported splitting
supercells as of 15-16z across south central TX. Similar conditions
will persist into the afternoon, which suggests that isolated large
hail will be possible with the strongest storms. Please refer to
mesoscale discussion 0219 for additional information.