Oct 28, 2020 2000 UTC Day 1 Convective Outlook
Updated: Wed Oct 28 19:58:01 UTC 2020 (20201028 2000Z Day 1 shapefile | 20201028 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20201028 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 39,527 3,613,455 New Orleans, LA...Mobile, AL...Metairie, LA...Gulfport, MS...Kenner, LA...
MARGINAL 49,928 9,142,346 Atlanta, GA...Montgomery, AL...Columbus, GA...Sandy Springs, GA...Roswell, GA...
Probabilistic Tornado Graphic
20201028 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
5 % 38,846 3,649,301 New Orleans, LA...Mobile, AL...Metairie, LA...Gulfport, MS...Kenner, LA...
2 % 49,890 9,044,671 Atlanta, GA...Birmingham, AL...Montgomery, AL...Columbus, GA...Sandy Springs, GA...
Probabilistic Damaging Wind Graphic
20201028 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
5 % 45,387 4,713,911 Montgomery, AL...Mobile, AL...Columbus, GA...Dothan, AL...Pensacola, FL...
Probabilistic Large Hail Graphic
20201028 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 281958

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0258 PM CDT Wed Oct 28 2020

   Valid 282000Z - 291200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THROUGH TONIGHT
   FROM SOUTHEAST LA/MS TO SOUTHERN AL/WESTERN FL PANHANDLE...

   ...SUMMARY...
   Hurricane Zeta may spawn a few tornadoes this afternoon through
   tonight from extreme southeast Louisiana/Mississippi into southern
   Alabama and the western Florida Panhandle.

   ...Southeast Louisiana...southern Alabama...Florida Panhandle...
   A tornado watch has been issued until 05Z in anticipation of
   increasing convection and shear associated with Hurricane Zeta.
   Low-level shear will continue to increase along and east of the
   center track later this afternoon and evening. MLCAPE 500-1000 J/kg
   is already in place well inland, which should maximize time for
   cells to attain rotation and pose a tornado threat.

   ..Jewell.. 10/28/2020

   .PREV DISCUSSION... /ISSUED 1115 AM CDT Wed Oct 28 2020/

   ...Southeast LA this afternoon to AL/GA through tonight...
   Hurricane Zeta is expected to make landfall late this afternoon
   along the LA coast to the south of New Orleans (please see latest
   NHC advisories for details).  The weakening remnants of Zeta will
   then accelerate northeastward through tonight across AL/GA, to the
   east of a deep midlevel low over the southern Plains.  An influx of
   tropical moisture and associated buoyancy will continue through the
   day along the north central and northeast Gulf coast as Zeta
   progresses north-northeastward.  

   Some more cellular convection has been observed this morning over
   the northern Gulf.  An increase in low-midlevel flow and vertical
   shear will occur as Zeta approaches the coast as the mid 70s
   boundary-layer dewpoints spread inland with muted daytime heating,
   which will increase the threat for supercells/tornadoes in the outer
   northeastern and eastern convective bands.  The more favorable
   phasing of buoyancy/vertical shear will occur this afternoon/evening
   from extreme southeast LA into southern AL/western FL Panhandle. 
   Poor lapse rates near the warm core center of Zeta and diurnal
   stabilization should gradually limit the threat farther inland
   overnight, though strong wind profiles and marginal CAPE rooted near
   the surface may still support an isolated tornado overnight into GA,
   to the southeast of the center.

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