spc ac 180733
day 3 convective outlook
nws storm prediction center norman ok
0233 am cdt tue jun 18 2019
valid 201200z - 211200z
...there is a slight risk of severe thunderstorms across
southeastern pa...central md...and northeast va...
isolated severe thunderstorms are possible from the northern
mid-atlantic states into portions of the southeast states thursday.
most likely locations for severe storms are southeast pennsylvania,
central maryland, and northeast virginia. isolated severe
thunderstorms are also possible across nebraska late thursday night
into early friday morning.
a shortwave trough will likely be moving through lower portions of
the oh valley early thursday morning. this shortwave is then
expected to continue eastward, extending from the lower great lakes
southwestward through the tn valley by 00z friday. while this
position currently appears to be the most likely scenario, the depth
of the shortwave trough as well as the speed of its eastward
progression will likely be modulated by the intensity and coverage
of thunderstorms in its proximity on wednesday, which is leading to
variance within the guidance.
strong flow aloft accompanying this shortwave will spread eastward
ahead of it into the mid-atlantic and eastern portions of the
southeast. the alignment of forcing for ascent, enhanced flow aloft,
and instability is expected across portions of northern mid-atlantic
including southeastern pa, central md, northeast va. negligible
height falls and warm temperatures aloft are expected to mitigate
thunderstorm coverage farther south across the piedmont and into the
southeast. any storms that do form could produce gusty downburst
winds but the limited coverage currently precludes higher than 5%
thunderstorms are expected to develop late thursday night/early
friday morning over nebraska as a strengthening nocturnal low-level
jet induces warm-air advection across the frontal zone. initial
storms will pose a risk for hail, with the potential for damaging
wind gusts becoming more likely if more linear organization begins
to occur near the end of the period.
click to get wuus03 ptsdy3 product
note: the next day 3 outlook is scheduled by 0730z