Current SPC Activity Chart

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SPC Activity Chart
Hazard Fri (11/22) Sat (11/23) Sun (11/24) Mon (11/25) Tue (11/26) Wed (11/27) Thu (11/28) Fri (11/29)
Severe Marginal No Severe No Thunder No Area No Area No Area No Area No Area
Fire No Critical No Critical No Area No Area No Area No Area No Area No Area

Forecast Discussion - Convective Outlook

   SPC AC 221950

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0150 PM CST Fri Nov 22 2019

   Valid 222000Z - 231200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF THE UPPER TEXAS COAST INTO CENTRAL MS THROUGH THIS EVENING....

   ...SUMMARY...
   Strong to briefly severe thunderstorms are possible from southeast
   Texas to central Mississippi through tonight.

   ...20z Update - East TX to Central MS...

   The previous outlook remains on track and no changes have been made
   to severe probabilities.  The 10% General Thunder line has been
   modified across parts of eastern TX to western KY to account for
   latest trends in radar/lightning data. The surface cold front
   extends from northeast MS southwestward into northern LA, then
   south/southwest toward the Middle and Upper Texas Coast. Some
   pockets of broken cloudiness have resulted in weak instability (less
   than 1000 J/kg MLCAPE) across western LA and deeper convection was
   developing along the cold front per latest visible imagery.
   Prefrontal showers and thunderstorms will limit downstream
   thermodynamic environment despite favorable deep layer shear for
   organized storms. A couple of short-lived strong storms could
   produce some strong wind gusts. Given the depth of the moist
   boundary layer and backed low level flow ahead of the front, a
   brief/weak tornado cannot be ruled out.

   ..Leitman.. 11/22/2019

   .PREV DISCUSSION... /ISSUED 1022 AM CST Fri Nov 22 2019/

   ...Lower MS/TN Valley regions through early Saturday...
   A lead shortwave trough over OK this morning will eject
   east-northeastward and weaken in confluent flow regime aloft, while
   an upstream speed max over the southern Rockies progresses eastward
   to the Ark-La-Tex by 23/12z.  At the surface, a cold front will move
   slowly southeastward across the Ark-La-Miss and southeast TX today. 
   A weak surface cyclone is expected to develop along the front
   tonight across the lower MS Valley and then move northeastward to
   the TN Valley by Saturday morning.  The warm sector south of the
   front is characterized by boundary-layer dewpoints ranging from the
   mid 60s in west central MS to the lower 70s along the upper TX
   coast, with weak-moderate buoyancy (MLCAPE 500-1000 J/kg).  The
   relatively larger buoyancy will likely be confined to along and
   south of a pre-frontal convective band from extreme southeast TX
   into central LA today, where the highest dewpoints will reside and
   some surface heating will occur in cloud breaks. 

   Since little in the way of cyclogenesis is expected today, low-level
   shear is likely near peak this morning and should weaken some this
   afternoon in the warm sector.  This leaves an environment with
   modest low-level shear and sufficient deep-layer shear/buoyancy for
   some embedded supercells with a low-end damaging wind and/or tornado
   threat.  Convection will persist through tonight and spread into
   northern AL, though lingering static stability near the ground
   should limit any threat for strong/severe storms this far northeast.

    

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