Valid 241200Z – 251200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Isolated thunderstorms may occur across parts of the Northeast
today. Severe thunderstorms are not expected.
A shortwave trough initially over the Mid-Atlantic will progress
northeastward across New England today, eventually reaching the
Canadian maritime provinces by the end of the period. A related
surface low will develop northeastward across coastal New England
and adjacent Atlantic waters. Strong ascent associated with a
low-level warm advection regime east of the surface low may
encourage isolated thunderstorm development this morning through
afternoon from southern NY into mainly coastal New England. Even
though strong flow will be present above a near-surface stable
layer, MUCAPE is expected to remain below 500 J/kg due to modest
mid-level lapse rates.
A cold front will continue southward across the southern FL
Peninsula today. Above the front, large-scale forcing for ascent
will remain minimal. Although shallow convection may develop along
the front this afternoon, very poor mid-level lapse rates will
likely limit the opportunity for lightning.
Mid-level lapse rates are forecast to steepen as a shortwave trough
moves across the Pacific Northwest late tonight. This should support
weak instability and some showers. While an occasional instance of
lightning cannot be completely ruled out along coastal WA/OR
tonight, coverage is currently expected to remain less than 10%.