Nov 11, 2021 2000 UTC Day 1 Convective Outlook
Updated: Thu Nov 11 19:53:02 UTC 2021 (20211111 2000Z Day 1 shapefile | 20211111 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20211111 2000 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
20211111 2000 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
20211111 2000 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
20211111 2000 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 111953

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0153 PM CST Thu Nov 11 2021

   Valid 112000Z - 121200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Organized severe thunderstorms are not expected today.

   ...20Z Update...

   ...AL...
   Overall forecast reasoning outlined in the previous outlook
   (appended below) remains unchanged. Updrafts have been relatively
   transient thus far, but a few more robust updrafts have recently
   developed. Instability continues to be limited by warm temperatures
   aloft, which should keep coverage and duration of any strong to
   severe storm low. Even so, steep low-level lapse rates could still
   result in a few damaging wind gusts.  

   ...VA/MD/PA...
   Consolidation/organization of a strongly forced, shallow convective
   line is expected to begin early tomorrow morning (9Z to 12Z) across
   eastern PA, central/eastern MD, and southeastern VA. At this time,
   it still looks like the main risk will occur after 12Z, with any
   strong gusts remaining too localized to introduce any wind
   probabilities with this outlook.

   ..Mosier.. 11/11/2021

   .PREV DISCUSSION... /ISSUED 1029 AM CST Thu Nov 11 2021/

   A broad upper trough is moving across the MS Valley, with an
   embedded shortwave trough rotating into LA/MS/AL.  Scattered
   thunderstorms are possible today and tonight ahead of the associated
   cold front as it moves across the Gulf Coast and TN Valley regions,
   and eventually into the Mid-Atlantic late tonight.

   ...AL...
   The one area of some concern for more robust convection will be over
   parts of AL this afternoon.  Visible satellite imagery shows partial
   sun and moderate heating occurring.  Low-level moisture is not
   particularly high and CAM solutions suggest that convection along
   the front will fail to become well-organized.  However,
   southwesterly low-level winds will be rather strong in this region,
   supporting a risk of gusty thunderstorm winds if a cell or two can
   develop bowing structures.  This area will continue to be monitored
   for an upgrade to MRGL in the afternoon update.

   ...VA/MD/PA...
   Very strong wind fields and strong frontogenesis may help to
   increase the risk of gusty winds as the front moves into the
   Mid-Atlantic region late tonight.  Present indications are that the
   main risk will begin around 12z, so will not include severe wind
   probabilities for this area at this time.

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   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z