Slight risk Friday! Awt
...Northeast...
An upper-level trough is forecast to move eastward into the
Northeast on Friday, as a cold front moves southeastward across the
region. Surface dewpoints ahead of the front are forecast to be in
the mid 60s F, which will result in a narrow corridor of instability
in the central and northern Appalachians. As surface temperatures
warm, thunderstorms will likely form in the higher terrain around
midday, with several small clusters moving eastward into the lower
elevations during the afternoon.
There is some disagreement concerning how much instability will
develop across the northeast on Friday. More aggressive solutions
suggest that moderate instability could be in place ahead of the
front by mid afternoon. Forecast soundings that show moderate
instability, have veered winds and steep lapse rates at low-levels,
and moderate to strong deep-layer shear. These soundings would
support a severe threat with either large hail or wind damage
possible. The severe threat would be concentrated near and after
peak heating as instability maximizes during the late afternoon.