Nov 22, 2021 1300 UTC Day 1 Convective Outlook
Updated: Mon Nov 22 12:29:23 UTC 2021 (20211122 1300Z Day 1 shapefile | 20211122 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20211122 1300 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
20211122 1300 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
20211122 1300 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
20211122 1300 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 221229

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0629 AM CST Mon Nov 22 2021

   Valid 221300Z - 231200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Severe thunderstorms are not expected across the contiguous United
   States today.

   ...Synopsis/Discussion...
   A progressive, strongly amplified synoptic pattern will continue
   through the period.  Synoptic troughing currently extends from
   Hudson Bay to the northern Gulf Coast.  This will be reinforced by a
   shortwave trough developing from initially low-amplitude vorticity
   banners now over MB/ND -- and forecast to move quickly southeastward
   while strengthening greatly.  By 12Z tomorrow, a strong basal
   perturbation should result near, or just offshore from, the GA/SC/NC
   coastline.  

   To the west, moisture-channel imagery indicated a strong shortwave
   trough over the northeast Pacific, between 140W-150W and 50N-40N. 
   This feature should cross coastal WA/OR between 06-12Z.  Behind the
   associated low-level frontal band, cooling midlevels and steepening
   lapse rates are forecast atop the marine boundary layer.  Forecast
   soundings suggest 50-250 J/kg MUCAPE, with buoyancy occasionally
   extending into icing layers suitable for isolated lightning
   production.  A small general-thunder area accordingly has been
   introduced for the last several hours of the period (overnight).

   At the surface, a cold front was analyzed at 11Z from a low near CHO
   southwestward across northern GA, southern MS and the TX coastal
   shelf waters of the Gulf.  This boundary will move southeastward
   through the period, overtaking an older, weaker baroclinic zone now
   located over south FL.  Weak, veered/westerly surface winds ahead of
   the front(s) will limit lift, but MLCINH will be weak as well. 
   Despite some minor mid/upper drying that has occurred, per
   comparisons of 12Z RAOBS with those from previous days, a few
   thunderstorms may form atop a favorably moist/prefrontal boundary
   layer over southeastern FL today, supported by 1000-1500 J/kg
   MLCAPE.  Lack of both vertical shear and stronger lift will limit
   organization.

   ..Edwards/Jewell.. 11/22/2021

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z