SPC AC 200819
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0219 AM CST Tue Nov 20 2018
Valid 221200Z - 231200Z
...NO THUNDERSTORM AREAS FORECAST...
Severe thunderstorms are not expected on Thursday.
...Synopsis and Discussion...
A progressive shortwave trough is expected to move eastward from its
early period position over the western Great Basin to the
central/southern Plains by 12Z Friday. Lee cyclogenesis is
anticipated ahead of this shortwave across the central High Plains,
with the resulting surface low likely located near the western KS/OK
by the end of the period. Enhanced surface pressure gradient between
this low and its associated troughing across the Plains and high
pressure over the Northeast will result in southerly wind across the
southern Plains throughout much the period. Even so, winds across
the Gulf will remain predominately easterly until after 00Z Friday,
limiting moisture return and keeping the air mass stable.
Consequently, thunderstorm development is not anticipated during the
period across the southern Plains.
The best chance for thunderstorms appears to be off of the northeast
FL/southeast GA coast where a low-amplitude shortwave will interact
with moist and marginally unstable air mass. Highest coverage will
be offshore with inland areas having thunderstorm probabilities of
less than 10%.
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z