Valid 101630Z – 111200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
SOUTHERN CALIFORNIA THIS AFTERNOON…AND OVER PARTS OF THE CENTRAL
PLAINS STATES TONIGHT….
Isolated severe thunderstorms are possible this afternoon over parts
of southern California, and tonight from parts of Kansas to the
Ozarks. Strong winds with fast-moving showers also may affect
portions of the Mid-Atlantic.
A relatively deep upper low is slowly approaching southern CA.
Satellite and radar imagery show multiple bands of showers that will
move/develop inland this afternoon. Relatively widespread cloud
cover will limit destabilization, but cooling midlevel temperatures
and significant large-scale forcing associated with an approaching
80 knot midlevel jet max will foster the development of a few
thunderstorms across portions of Los Angeles and Ventura counties
CA. This activity is forecast to rotate into Kern county later this
afternoon, with recent CAM solutions suggesting one or two storms
becoming organized with a risk of gusty winds or small hail. The
overall risk of severe storms appears marginal.
Strengthening low-level southwesterly flow across parts of the
central Plains will promote scattered thunderstorm development
tonight (after midnight) across central KS. Forecast soundings
suggest the potential for elevated CAPE values of 500-800 J/kg,
along with sufficient cloud-layer shear for a few strong storms.
The initial storms may produce hail, but a general evolution toward
bowing segments is expected through the late-night period. A stable
layer near the ground will limit the risk of severe wind gusts, but
some gusty winds are possible.