SPC AC 090553

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1253 AM CDT Fri Apr 09 2021

   Valid 101200Z - 111200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   THE CENTRAL GULF COAST INTO WESTERN GA...

   ...SUMMARY...
   Scattered severe thunderstorms are expected from southeast Louisiana
   eastward to the Florida Panhandle, and northward across much of
   Alabama and western Georgia on Saturday.

   ...Synopsis...

   A compact upper low over the central Plains/mid-MO Valley and its
   attendant trough will pivot northeast toward the Great Lakes through
   the period. A secondary shortwave impulse located over the lower MS
   Valley will quickly lift northeast toward the southern/central
   Appalachians by 00z, while becoming increasingly absorbed by the
   main upper low/trough. A surface low is forecast over the mid-MS
   Valley Saturday morning, with a cold front trailing toward the
   southwest from near St. Louis to the Arklatex vicinity and arcing
   toward the Edwards Plateau. Ahead of the front, a mature and likely
   severe QLCS will likely be ongoing across parts of the lower MS
   Valley/central Gulf Coast states. Severe storms are expected to
   continue through the morning and into the afternoon with the QLCS as
   it shifts east/southeast across parts of LA/MS/AL/GA/FL. Further
   north, isolated severe thunderstorms are possible closer to the
   surface low, ahead of the eastward-surging cold front across parts
   of the lower Ohio Valley toward Lake Erie.

   ...Central Coast States/western GA...

   Uncertainty still exists regarding the extent of the severe threat
   on Saturday. This will mainly be driven by how for east/southeast
   the ongoing QLCS progresses during the Day 1 period. As such, the
   western and northern margins of the Slight risk area could still
   change in forthcoming outlooks. Nevertheless, the bulk of severe
   potential is expected from southeast LA into southern MS/AL and the
   western FL Panhandle. Moderate instability and weak inhibition will
   exist downstream of the ongoing QLCS Saturday morning, with a 40-50
   kt southerly low level jet being maintained through at least midday.
   Forecast soundings indicate potential for strong, damaging gusts,
   some possibly greater than 65 kt, given the strength of deep-layer
   flow and the mature nature of the ongoing convective system.
   Additionally, large, curved low level hodographs will exist closer
   to the Gulf coast, and a few mesovortex tornadoes also will be
   possible. The severe threat should gradually diminish with eastward
   extent during the afternoon as the line of convection tracks toward
   eastern GA/northern FL as stronger wind profiles will pivot
   northeast of the region and the thermodynamic environment becomes
   less favorable.

   ...Ohio Valley/Great Lakes vicinity...

   Strong southerly low level flow will transport mid 50s to near 60s F
   dewpoints into the Lower OH Valley region ahead of the
   eastward-advancing cold front and surface low. While midlevel lapse
   rates will remain modest, this should be sufficient for around 500
   J/kg MLCAPE. Additionally, strong heating will allow temperatures to
   climb into the mid/upper 70s, resulting in steepening low level
   lapse rates. Given strong deep layer winds, fast moving
   clusters/bowing segments could result in isolated damaging gusts.

   ..Leitman.. 04/09/2021

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   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 1730Z