SPC AC 121927

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0227 PM CDT Wed Mar 12 2025

   Valid 141200Z - 151200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER MUCH OF
   THE MIDDLE TO LOWER MISSISSIPPI VALLEY...OHIO AND TENNESSEE
   VALLEYS...

   ...SUMMARY...
   A regional outbreak of severe storms is expected across much of the
   Mississippi Valley, eastward to the Lower Ohio and Tennessee Valleys
   late Friday afternoon into Saturday morning. Widespread damaging
   winds, several tornadoes, and hail will all be possible.

   ...Synopsis...
   An upper low associated with a powerful shortwave trough will deepen
   through the period, moving from NM at 12Z Friday to WI by 12Z
   Saturday. An associated intense midlevel speed max will pivot from
   OK at midday into the mid MS Valley by 00Z, then will lose intensity
   late as it approaches MI. Large-scale ascent will be maximized north
   of the midlevel jet roughly from the Ozarks and Ohio Valley
   northward.

   At the surface, low pressure (sub 980 mb) will deepen from KS into
   IA through evening, with a large expanse of southerly winds across
   the warm sector aiding northward moisture advection.

   Behind the primary wave, another system will be dig into northern MX
   and TX Saturday morning. This should maintain gradual height falls
   over the southeastern states through the period, despite being south
   of the initial system.

   ...Most of the area from the mid MO Valley into the TN Valley...
   A classic, progressive deep-layer cyclone will interact with a
   increasingly unstable air mass to produce widespread wind damage
   beginning near the KS/MO and OK/AR borders during early afternoon,
   and expanding northeast across much of MO, IA, IL, IN, western KY
   and parts of western TN through evening. Not only will extreme wind
   field favor damaging winds, but profiles will also favor supercells
   capable of fast-moving tornadoes, whether a broken line or in QLCS
   fashion along surging outflows. The steep lapse rates and rapid
   changes overall will also support strong tornado potential
   interspersed with the damaging wind area.  Last, cells will also
   produce hail over northern areas where temperatures aloft are cold.
   ...MS/AL/TN Overnight...
   As the upper wave departs to the north, mid to perhaps upper 60s F
   dewpoints will surge north across MS, western AL and the western FL
   Panhandle during the evening and overnight. As mentioned, height
   falls will be maintained due to the secondary wave moving into TX.
   The result will be a persistent 50-60 kt low-level jet beneath 60 kt
   midlevel southwesterlies, and increasing boundary-layer moisture.
   This regime is likely to support scattered thunderstorms after 06Z,
   and the overall environment conditionally supports strong tornadoes.
   The severe risk will only increase into Saturday/D4. As such, have
   extended the Enhanced Risk farther south across MS and western AL.

   ..Jewell.. 03/12/2025

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z