Mar 13, 2021 0830 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat Mar 13 07:59:22 UTC 2021 (20210313 0830Z Day 3 shapefile | 20210313 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
20210313 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 130759

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0159 AM CST Sat Mar 13 2021

   Valid 151200Z - 161200Z


   Appreciable severe risk is not evident at this time across the U.S.
   on Monday.

   An upper low initially over the central Plains is forecast to lift
   northeastward with time, becoming increasingly weak/sheared through
   the period.  Farther west, a second low entering northern
   California/western Oregon early, is expected to pivot southeastward
   across the Great Basin toward the Desert Southwest with time.

   At the surface, a weak west-to-east baroclinic zone is forecast to
   evolve with time, from Oklahoma eastward into the Mid South.

   A band of generally weak convection should be crossing western
   portions of Tennessee and Kentucky/Mississippi/eastern Louisiana and
   vicinity early in the day, with some embedded/occasional lightning. 
   Though weak instability should limit convective intensity across
   most areas, through most of the period, a small window of
   opportunity for slightly more robust convection may evolve during
   the afternoon, in the west-central Alabama vicinity.  With shear
   expected to be plenty sufficient for organized/rotating storms,
   ample instability would yield potential for severe weather. 
   However, at this time, it appears that even through the afternoon,
   CAPE should remain minimal at best.  Therefore, though a stronger
   storm capable of gusty winds or even a brief tornado cannot be ruled
   out within a zone centered over the west-central Alabama area,
   potential appears too low to highlight with a risk area at this

   ..Goss.. 03/13/2021