SPC AC 221727

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1127 AM CST Tue Jan 22 2019

   Valid 231200Z - 241200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY
   AFTERNOON INTO WEDNESDAY NIGHT NEAR NORTHEASTERN GULF COASTAL
   AREAS...

   ...SUMMARY...
   Strong storms may impact northeastern Gulf coastal areas Wednesday
   afternoon through Wednesday night, perhaps accompanied by at least
   some risk for severe weather.

   ...Synopsis...
   Downstream of large-scale mid/upper ridging, which is forecast to
   continue to build within the mid-latitude westerlies over the
   eastern Pacific, models indicate that large-scale troughing will
   continue to evolve over interior North America through this period. 
   This latter regime will include at least one impulse of Arctic
   origins digging toward the central Canadian/U.S. border area, and
   another of mid-latitude Pacific origins digging inland of the
   Pacific Northwest coast into the Rockies.

   Preceding these features, a pair of short waves (comprising
   significant troughing now crossing portions of the central Plains
   and southern Rockies) will remain progressive, turning northeastward
   and eastward, across the Great Lakes into Quebec, and across the
   lower Rio Grande Valley toward the Appalachians.  The northern
   impulse may be accompanied by appreciable deepening of the primary
   associated surface cyclone, while the southern impulse supports
   secondary surface frontal wave development to the lee of the
   southern Appalachians late Wednesday through Wednesday night.

   Within the evolving pre-frontal warm sector across the eastern Gulf
   Coast states into the southern Mid Atlantic, southward through the
   eastern Gulf of Mexico and Florida Peninsula, considerable
   intensification of south to southwesterly lower/mid tropospheric
   flow is forecast, including speeds on the order of 40-70+ kt at 850
   mb.

   ...Southeast...
   With the mid-level thermal trough forecast to generally lag to the
   west/northwest of the warm sector through the period, relatively
   warm layers aloft, coupled with rather modest low-level moisture
   return off a still modifying Gulf boundary layer, appears likely to
   confine any appreciable boundary layer destabilization to the
   eastern/northeastern Gulf of Mexico.  However, guidance indicates
   that surface dew point increases to the lower/mid 60s, accompanied
   by weak boundary layer destabilization, is at least possible into at
   least portions of northeastern Gulf coastal areas.  There remains
   some spread among the various model output concerning where, perhaps
   as far west as southeastern Louisiana coastal areas by midday
   Wednesday, and perhaps as far east as the Tampa Bay area by 09-12Z
   Thursday.

   Given at least weak boundary layer destabilization near/inland of
   coastal areas, in the presence of strong low-level and deep layer
   shear, the environment probably will become conducive to organized
   severe weather potential, generally associated with convection
   spreading inland off the Gulf of Mexico.  This may include an
   evolving pre-frontal squall line, perhaps preceded by isolated
   discrete supercell development, accompanied by a risk for a tornado
   or two, in addition to potentially damaging wind gusts.

   ...MAXIMUM RISK BY HAZARD...
   Tornado:   2%     - Marginal
   Wind:      5%     - Marginal
   Hail:     <5%     - None

   ..Kerr.. 01/22/2019

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0700Z