SPC AC 170721

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0221 AM CDT Thu Apr 17 2025

   Valid 191200Z - 201200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL TEXAS
   INTO SOUTHERN MISSOURI...

   ...SUMMARY...
   Isolated to scattered severe thunderstorms are possible from central
   Texas into the Ohio Valley on Saturday.

   ...Southern Plains to southern MO...

   An upper shortwave trough over the Southwest will pivot east toward
   the southern Plains on Saturday/Saturday night. This will maintain
   strong southwesterly flow aloft from TX into the Midwest. At the
   surface, a front is expected to be draped from southern IL/MO into
   northwest TX during the morning, with a dryline extending southward
   across west-central TX in the vicinity of the Big Bend. Southerly
   low-level flow will maintain a moist airmass ahead of these surface
   boundaries, with dewpoints generally in the low/mid 60s F. Some
   convection could be ongoing during the morning in a warm advection
   regime prior to the low-level jet weakening modestly during the day.
   Stronger heating ahead of the surface boundary could allow for weak
   to moderate destabilization by afternoon, and additional convection
   is likely along the cold front/dryline as large-scale ascent
   increases with the approach of the upper shortwave trough. 

   Vertical wind profiles suggest supercell potential, but storm mode
   may quickly trend toward clusters/linear segments. Some risk for
   large hail and damaging gusts appears possible with this activity
   during the late afternoon into the nighttime hours, with initial
   convection developing over TX/OK and spreading into the Ozarks after
   00z. 

   ...Ohio Valley...

   An upper shortwave trough will migrate east across Ontario/Quebec
   and the Great Lakes on Saturday. This will bring a belt of strong
   deep-layer westerly flow across the Ohio Valley/Great
   Lakes/Northeast vicinity. A cold front and associated baroclinic
   zone will sag south/southeast across the Ohio Valley vicinity with a
   narrow corridor of modest boundary layer moisture forecast within
   this region. Severe potential will largely be modulated by ongoing
   convection Saturday morning and generally weak instability and lapse
   rates. Nevertheless, strong flow and sufficient instability may
   support strong gusts with thunderstorm clusters during the morning
   and afternoon hours.

   ..Leitman.. 04/17/2025

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1930Z