Dec 10, 2019 0830 UTC Day 3 Severe Thunderstorm Outlook
Updated: Tue Dec 10 07:11:58 UTC 2019 (20191210 0830Z Day 3 shapefile | 20191210 0830Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0830 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Graphic
20191210 0830 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 100711

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0111 AM CST Tue Dec 10 2019

   Valid 121200Z - 131200Z


   Isolated to scattered thunderstorms are expected across portions of
   the Deep South and central Gulf Coast eastward to the Florida

   Broad, cyclonically curved mid-level flow will encompass much of the
   Lower 48 from the central Plains through the East Coast.  A
   shortwave trough will migrate through this flow from the central
   Plains to the Mid-Mississippi Valley.  The approaching mid-level
   trough will induce modest cyclogenesis across the northern Gulf of
   Mexico, with increasing low-level flow atop a shallow cool boundary
   layer across the Southeast encouraging development of showers and a
   few thunderstorms across the Lower Mississippi Valley in the
   afternoon - spreading eastward toward the southern Appalachians
   through the night.  Isolated thunderstorms will also develop across
   the Florida Peninsula during the afternoon as well, and very cold
   air aloft may result in a couple lightning flashes across western
   Washington State.

   ...Coastal areas of southeast Louisiana through Alabama...
   The combination of surface cyclogenesis across the north-central
   Gulf of Mexico and increasing low-level flow across the region will
   result in eventual northward evolution of a moist low-level airmass
   characterized by near 70s F dewpoints.  The northward progression of
   this airmass will likely demarcate the northern limit of any
   potential for surface-based convection, and most models suggest that
   this risk of surface-based activity should hold off over land areas
   until after 12Z Friday.  A faster northward progression of this
   airmass may result in a brief window for supercellular development
   near coastal areas, however, given vertically veering wind profiles
   and modest buoyancy.  Pending evolution of this airmass, low severe
   probabilities may be needed in later outlooks.

   ..Cook.. 12/10/2019