Dec 21, 2017 0100 UTC Day 1 Convective Outlook
Updated: Thu Dec 21 01:00:34 UTC 2017 (20171221 0100Z Day 1 shapefile | 20171221 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20171221 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Tornado Graphic
20171221 0100 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20171221 0100 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
Probabilistic Large Hail Graphic
20171221 0100 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
No Risk Areas Forecast
   SPC AC 210100

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0700 PM CST Wed Dec 20 2017

   Valid 210100Z - 211200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Severe thunderstorms are not expected the remainder of the period.

   ...Discussion...
   A short-wave trough embedded within westerly mid-level flow
   continues moving quickly east across the southeast U.S. at this
   time, with associated ascent to move offshore after midnight. 
   Onshore lightning has already dissipated, with only a small band of
   low-topped showers moving quickly across Georgia at this time.  With
   the rapid eastward translation of the convection and associated
   ascent aloft, and continued diurnal cooling/stabilization, little
   onshore lightning and no severe weather can be expected the rest of
   the period across this area.

   Elsewhere over the U.S., thunderstorms are not anticipated.

   ..Goss.. 12/21/2017

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z