Valid 221300Z – 231200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
SOUTH-CENTRAL CALIFORNIA COAST…
…SUMMARY…
Isolated strong storms may produce gusty winds over parts of coastal
central/southern California this afternoon and evening.
…Coastal central/southern California…
An upper low centered around 300 miles west of the SoCal coast this
morning will continue eastward in conjunction with a mid-level speed
max. Mid-level temperatures will cool to near -24C by evening, with
moderate heating/cloud breaks allowing for surface-based parcels to
become modestly unstable this afternoon. Strengthening winds through
a deep layer may support semi-organized convection, with the most
probable time frame for any stronger storms between 21Z-03Z. Gusty
winds are the primary threat with this activity.
…Mid/Deep South and Tennessee Valley…
A shortwave trough will continue east-northeastward today and
gradually weaken as it spreads over the Tennessee Valley toward the
southern Appalachians/Carolinas, leaving the strongest mid-level
flow well north of appreciable instability. Forecast data suggests
60 F surface dew points will advance northward across much of east
Texas/Louisiana and southern portions of Mississippi/Alabama in
tandem with a northward-shifting warm front. However, overall
buoyancy will remain weak aside from limited low-level convergence
as shortwave ridging occurs today. Severe thunderstorms appear
unlikely.
…Central Plains…
Near a surface trough/front, weak buoyancy will develop across the
central Plains as surface temperatures warm into the 50s F from
western Kansas into central Nebraska. Most convection will struggle
to produce lightning, but a few flashes are possible with the
strongest updrafts.
..Guyer.. 03/22/2020
$$