Severe Storm Outlook Narrative (AC)
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ACUS02 KWNS 220445
SPC AC 220444

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1044 PM CST Tue Nov 21 2017

Valid 231200Z - 241200Z


A few general thunderstorms are expected across the Florida
Peninsula on Thursday.

...FL Peninsula...
The main impetus and focus for thunderstorm development Thursday and
Thursday night will be a slow-moving upper-level trough over the
Gulf of Mexico.  A weak area of low pressure will gradually develop
from the central into the eastern Gulf with moist low-level
trajectories emanating from the northwest Caribbean into the FL
Peninsula vicinity.  Buoyancy is forecast to lessen with northward
extent away from the Gulf Stream/FL Straits.  The latest NAM
(22/00Z) showed a slightly stronger PV anomaly encroaching on the FL
Gulf Coast during the overnight hours.  Concurrent with this
feature, stronger low-level mass response was depicted.  However,
time-lagged versions of the GFS, ECMWF, CMC, and UKMET all show a
weaker low-level response.  It seems plausible based on the NAM and
a few convection-allowing models with NAM input that some risk for a
strong thunderstorm or two would be possible over the Keys,
Everglades, and perhaps along the immediate Gulf Coast south of
Tampa Bay.  Yet, this scenario seems unlikely given the model
variability/consensus.  For these reasons, will maintain a less than
5-percent severe risk for this outlook update.

..Smith.. 11/22/2017

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