SPC AC 260819

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0219 AM CST Sun Dec 26 2021

   Valid 281200Z - 291200Z

   ...NO SEVERE THUNDERSTORM AREAS FORECAST...

   ...SUMMARY...
   Isolated to widely scattered thunderstorms will be possible from the
   ArkLaTex into the Ohio Valley on Tuesday.

   ...Synopsis...
   A mid-level shortwave trough will be located near the central High
   Plains at 12Z Tuesday. This trough will phase with the larger upper
   trough which will move through the northern Plains during the day. A
   strong surface low will be present across the central Plains on
   Tuesday morning, but this surface low will weaken as it moves
   northeast. A surface front will initially lift northward as a warm
   front, but will stall near the Ohio River by Tuesday evening as the
   surface low weakens. 

   ...Portions of the Mid-Mississippi Valley into the Ohio Valley...
   Strong isentropic ascent should lead to widespread precipitation
   north of the warm front during the day Tuesday as the low-level jet
   strengthens and advects moisture into the region. Forecast soundings
   show some weak instability, and therefore some lightning may be
   possible from this activity. Farther south, a lack of deeper
   moisture, and warm temperatures aloft from a remnant EML should
   limit storm coverage across much of the warm sector. By Tuesday
   night, better quality moisture will start to overspread much of the
   warm sector and the warmer mid-level temperatures will start to
   cool. Therefore, some storm activity is possible along the surface
   front late Tuesday night/early Wednesday morning, but large-scale
   forcing will be limited by this time, and the frontal circulation
   may not be strong enough to initiate convection. If any storms can
   develop Tuesday night/Wednesday morning along this frontal zone,
   they could become strong given the favorable shear and at least weak
   buoyancy. However, the uncertainties regarding storm coverage (if
   any) and the weak instability preclude the need for severe weather
   probabilities at this time.

   ..Bentley.. 12/26/2021

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   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0830Z