Severe Storm Outlook Narrative (AC)
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ACUS48 KWNS 170821
SPC AC 170820

Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0320 AM CDT Sat Mar 17 2018

Valid 201200Z - 251200Z

On Tuesday/D4, a shortwave trough will move rapidly across the
northern Gulf of Mexico, with a cyclonically curved 100 kt midlevel
speed max approaching FL by 00Z Wednesday. At the surface, low
pressure will exist over southern GA, and will deepen during the
evening as it shifts offshore. A cold front will move gradually
southward across FL throughout the day, veering low-level winds with
time. Mean wind speeds will be quite strong, with around 50 kt at
850 mb, and increasing speed shear with height. Forecast
thermodynamics support severe storms as well, with 700-500 mb lapse
rates in excess of 7 C/km and 1000-1500 J/kg MUCAPE. The
unidirectional wind profile will support bowing storms capable of
damaging winds, mainly over north-central FL prior to the low
shifting northeast of the area.

Beyond D4, the pattern becomes much less supportive of severe
weather, with a ridge over the Plains flanked by expansive regions
of cyclonic flow aloft over the east and west.

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