Valid 041630Z – 051200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Severe thunderstorms are not expected today.
A sharp upper trough will continue moving across the eastern U.S.
today, as an associated cold frontal advance — comprised of two
successive wind shift/airmass changes — continues across the East
Coast states. These two wind shifts — one now off the middle and
southern Atlantic Coast and the second shifting east of the
Appalachian Crest — will gradually congeal into one, more cohesive
front, as it shifts eastward across Florida and eastward across the
western Atlantic through this evening.
Aloft, a lower-amplitude pattern will continue to spread across the
U.S. in the wake of the eastern trough as it continues progressing
off the middle and southern Atlantic Coasts tonight. Two
smaller-scale upstream short-wave troughs will shift through the
more westerly upstream flow regime — one crossing the Rockies and
reaching the Plains overnight, while the second reaches the Pacific
Northwest/northern and central California Coasts late.
Aside from a few lightning flashes which may occur near the end of
the period over the Pacific Northwest Coast area, showers and a
few/embedded thunderstorms will also continue to affect Florida
today. The convection is occurring primarily within a band that
extends from near Daytona to the Tampa area, along the initial
front/wind shift. This band will continue shifting southward in
conjunction with the frontal advance through this afternoon, before
moving offshore/south of the Keys this evening. With very weak
lapse rates across the area, yielding minimal CAPE, severe risk will