Valid 121200Z – 131200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Isolated to scattered thunderstorms are expected mainly this evening
and tonight across the Southeast States. Isolated thunderstorms are
also possible along the Pacific Northwest Coast today. No severe
weather is expected.
Southerly 900-850 mb winds will increase over the Southeast States
later today and tonight in association with a progressive shortwave
trough currently moving through the central and southern Plains.
While richer low-level moisture will remain confined to south of a
warm front that will move northward through FL and the northern
Gulf, moisture transport above the cool surface layer will result in
destabilization across the southeast States with MUCAPE from 200-400
J/kg in cool sector and 500-1000 J/kg across the central and
southern FL warm sector. Primary focus for thunderstorms will likely
be this evening into tonight in cool sector as isentropic ascent and
destabilization increase across the Southeast States.
…Pacific Northwest Coast…
Cold temperature aloft with steep lapse rates and embedded vorticity
maxima north of a strong upper jet core will maintain the threat for
isolated thunderstorms within a broader area of showers. The
greatest coverage of thunderstorms are expected along the Pacific
Northwest coast where the influence of the marine layer will
contribute to greater instability. However, a few lightning flashes
are also possible farther inland across parts of eastern OR into ID.