Oct 21, 2018 0600 UTC Day 1 Convective Outlook
Updated: Sun Oct 21 05:08:49 UTC 2018 (20181021 1200Z Day 1 shapefile | 20181021 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20181021 1200 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
20181021 1200 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
20181021 1200 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
20181021 1200 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 210508

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1208 AM CDT Sun Oct 21 2018

   Valid 211200Z - 221200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Thunderstorms will be possible across the southwestern U.S. today.
   Severe weather is not expected across the continental United States
   today or tonight.

   ...DISCUSSION...
   An upper-level trough will move eastward away from the East Coast
   today as surface high pressure settles in across the eastern third
   of the nation. Another upper-level trough will approach Baja
   California. Moisture advection ahead of the trough will increase
   surface dewpoints across parts of the southwestern U.S. In response,
   enough instability should be in place by afternoon for thunderstorm
   development from Arizona northward into Utah and westward into parts
   of Nevada and California. In spite of this, instability and shear is
   not expected to be sufficient for a severe threat.

   ..Broyles/Cook.. 10/21/2018

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z