Dec 18, 2017 0830 UTC Day 3 Severe Thunderstorm Outlook
Updated: Mon Dec 18 07:41:27 UTC 2017 (20171218 0830Z Day 3 shapefile | 20171218 0830Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20171218 0830 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 41,585 7,796,998 Atlanta, GA...Birmingham, AL...Sandy Springs, GA...Macon, GA...Tuscaloosa, AL...
Probabilistic Graphic
20171218 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
5 % 41,810 7,807,988 Atlanta, GA...Birmingham, AL...Sandy Springs, GA...Macon, GA...Tuscaloosa, AL...
   SPC AC 180741

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0141 AM CST Mon Dec 18 2017

   Valid 201200Z - 211200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   MISSISSIPPI...ALABAMA AND GEORGIA...

   ...SUMMARY...
   Scattered thunderstorms are forecast to move eastward from central
   Mississippi into north-central Georgia on Wednesday. The convection
   may be accompanied by a marginal tornado and strong wind-gust
   threat.

   ...Mississippi/Alabama/Georgia...
   An upper-level trough will move eastward from the Arklatex across
   Mississippi and Alabama on Wednesday. At the surface, a cold front
   is forecast to advance eastward from the lower Mississippi Valley
   into the central Gulf Coast States. Ahead of the front, a moist
   airmass will be in place with surface dewpoints in the 60s F.
   Scattered convection is forecast to be ongoing at 12Z on Wednesday
   in central Mississippi along the western edge of a 40 to 50 kt
   low-level jet. This convection is forecast to move into
   north-central Alabama by midday and into north-central Georgia in
   the afternoon. Forecast soundings along this corridor from late
   morning into the afternoon show MLCAPE values in the 250 to 500 J/kg
   range with 0-6 km shear of 60 to 70 kt. This should be enough for a
   marginal severe threat. Forecast soundings also show 0-1 km shear at
   or above 30 kt which should be sufficient for a marginal tornado
   threat. A potential may also exist for strong wind gusts.

   ..Broyles.. 12/18/2017

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z