SPC AC 120520

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1220 AM CDT Sat Aug 12 2017

   Valid 131200Z - 141200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL
   AND SOUTHERN HIGH PLAINS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST
   NM TO NORTHEAST WY...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF MAINE...

   ...SUMMARY...
   Scattered thunderstorms, a few severe, are expected to develop
   across the central and southern High Plains Sunday. A few strong
   storms may also develop across portions of Maine.

   ...Central/Southern High Plains...

   Northern High Plains short-wave trough will translate to a position
   from the eastern Dakotas into the central Plains at daybreak Sunday.
   In the wake of this feature modest northwesterly mid-level flow will
   extend along a corridor from the High Plains into the base of the
   trough over the mid MS Valley region. While short-wave troughing
   will shift east of the SLGT risk region early, considerable amount
   of convection is once again expected to develop over the higher
   terrain of WY, south into NM. Some of this activity may drift into
   an axis of considerable more buoyancy across the plains where shear
   profiles are expected to support organized convection. Additionally,
   strong surface heating near the lee trough, from southeast WY into
   eastern NM, should result in thunderstorm development over the
   plains after 22z. Veering/increasing wind profiles with height
   suggest a few supercells are possible.

   ...Maine...

   Seasonally strong mid-level height falls will spread across northern
   New England during the day2 period ahead of a significant short-wave
   trough that will advance to a position from southeast QC to MA by
   18z. Latest short-range guidance suggests a narrow corridor of
   strong pre-frontal heating will be noted from MA into northern ME.
   While deep-layer flow veers ahead of the cold front this will allow
   air mass to destabilize sufficiently for potential isolated
   thunderstorm development along the front, possibly by 17z. Forecast
   shear profiles would support organized updrafts and isolated
   supercells may develop, especially across Downeast ME in closer
   proximity to mid-level jet. Will maintain 5% severe across this
   region due to the uncertainty of storm coverage; however, forecast
   shear/buoyancy across Downeast ME supports the potential for
   organized convection.

   ..Darrow.. 08/12/2017

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