Valid 141630Z – 151200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Severe thunderstorms are not expected across the contiguous U.S.
today and tonight.
…Southern Plains through lower Mississippi Valley…
Scattered showers with embedded widely scattered thunderstorms will
persist from TX into the lower MS valley region in association with
modest isentropic ascent north of a warm front. Sufficient low-level
shear may exist to support weak/transient updraft rotation with any
surface-based storm developing along the warm front across southeast
TX, but any severe threat should remain very marginal. Greater
coverage of thunderstorms might occur later tonight over the
Ark-La-Tex region as destabilization resulting from low-level
theta-e advection increases north of the warm front.
…Middle Mississippi Valley region…
At least weak destabilization will occur in this region overnight as
a strengthening southwesterly low-level jet transports modifying
continental-polar air northward beneath eastward-advecting plume of
steeper lapse rates. Increasing forcing for ascent within this zone
of isentropic ascent downstream from an approaching northern-stream
shortwave trough should contribute to initiation of a few elevated
thunderstorms from MO into IL and WI later tonight.