Storm Prediction Center Mesoscale Discussion 2121

   Mesoscale Discussion 2121
   NWS Storm Prediction Center Norman OK
   0602 PM CDT Thu Sep 26 2024

   Areas affected...Much of the Florida Peninsula and far southern
   Georgia

   Concerning...Tornado Watch 683...685...

   Valid 262302Z - 270030Z

   The severe weather threat for Tornado Watch 683, 685 continues.

   SUMMARY...The tornado threat across much of the Florida Peninsula
   and southern Georgia will continue well into the evening hours. A
   replacement tornado watch will be needed soon.

   DISCUSSION...The latest satellite, lightning, and radar imagery
   associated with Helene, and its extrapolation, continue to suggest
   the potential for several more bands of low-topped thunderstorms
   extending over much of the FL Peninsula and far southern GA through
   tonight. Increasing low-level flow associated with Helene remains
   apparent on the TBW VWP, with a slow increase of around 5-10 kt of
   shear observed in the lowest 1 km over the past hour. Although
   buoyancy will slowly decrease overnight, the aforementioned shear
   will yield 0-1 km SRH around 400-700 m2/s2 for several hours within
   all eastern quadrants of Helene. Brief tornadoes are expected within
   this zone of substantial, increasing low-level shear as far north as
   the eastern FL Panhandle. A new tornado watch will likely be issued
   within the next hour.

   ..Barnes/Gleason.. 09/26/2024

   ...Please see www.spc.noaa.gov for graphic product...

   ATTN...WFO...MFL...MLB...TBW...JAX...TAE...

   LAT...LON   26358186 26408217 27508271 28008289 28828268 29228296
               29878364 30308469 30998466 31658321 31648210 31198152
               29758092 27218083 26358186