SPC AC 231947

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0247 PM CDT Tue May 23 2023

   Valid 232000Z - 241200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM NORTHEASTERN
   NEW MEXICO SOUTHEASTWARD INTO CENTRAL TEXAS...

   ...SUMMARY...
   Scattered severe thunderstorms will be possible across west to
   central Texas later this afternoon into tonight. A few intense
   storms are possible this evening. These will be capable of producing
   very large hail to around baseball size, severe wind gusts to around
   80 mph, and brief tornadoes.

   ...Discussion...
   Aside from minor adjustments to the thunder line in a few areas,
   substantial changes to the outlook do not appear necessary at this
   time, as the current forecast continues to reflect ongoing and
   anticipated convective evolution.

   The most substantial change to the severe risk areas at this time,
   is to extend the 5% hail probability area northwestward across
   Florida into the Panhandle, where a few storms have occasionally
   intensified to levels consistent with hail in excess of 1" in
   diameter.

   ..Goss.. 05/23/2023

   .PREV DISCUSSION... /ISSUED 1129 AM CDT Tue May 23 2023/

   ...Southern High Plains to central TX...
   With widespread upper 50s to mid 60s surface dew points established
   and steeper mid-level lapse rates (around 1 C/km greater) sampled in
   12Z MAF/AMA soundings compared to yesterday, larger MLCAPE from
   2000-3000 J/kg is anticipated at peak heating ahead of the dryline
   in west to central TX. This will aid in a broader swath of severe
   thunderstorm potential during the late afternoon and evening
   relative to yesterday.

   A trio of minor MCVs are evident in water vapor/radar imagery...over
   east TX, north-central OK, and northeast NM. The latter impulse in
   conjunction with terrain enhancement and weak convergence along the
   dryline should aid in scattered thunderstorms forming towards
   mid-afternoon from northeast NM to the South Plains, with isolated
   thunderstorms also over the Trans-Pecos. Despite weak SRH initially,
   30-35 kt effective bulk shear with relatively straight-line
   hodographs should foster outflow-dominated, splitting supercells
   with a primary threat of very large hail. Morning CAM guidance is
   varied in the duration of discrete supercell mode but the consensus
   appears to indicate a quicker transition to upscale growth relative
   to yesterday's event. The most likely area for MCS occurrence
   appears to be across the Big Country vicinity, with severe wind gust
   potential likely lingering longer tonight (wind reports yesterday
   ending around 02Z) and farther southeast into central TX, owing to
   the greater buoyancy today.

   ...FL...
   An MCV remains anchored over west-central AL with a low-amplitude
   trough extending south into the northern Gulf. Ahead of this,
   scattered thunderstorms are ongoing over the northeast Gulf and will
   also occur in a few hours along the sea breezes across the
   peninsula. Weak mid-level lapse rates sampled in 12Z soundings will
   continue to be a limiting factor to more substantial instability,
   but 20-30 kt effective bulk shear should support multicell
   clustering with a primary threat of sporadic downbursts producing
   locally damaging winds.

   ...Northeast NV/northwest UT and southeast ID...
   An upper trough with a series of embedded shortwave impulses will
   remain anchored from the Canadian Rockies south into northern CA.
   The fringe of enhanced mid-level south-southwesterlies should
   overlap a weak buoyancy plume characterized by MLCAPE from 250-750
   J/kg over the northern Great Basin this afternoon. Scattered
   multicell clusters are expected in this corridor, with the potential
   for isolated severe gusts and small hail.

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