SPC AC 141731

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1231 PM CDT Fri Aug 14 2020

   Valid 151200Z - 161200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE CENTRAL
   HIGH PLAINS...NORTHERN MINNESOTA...PARTS OF THE MIDWEST...AND THE
   MID ATLANTIC...

   ...SUMMARY...
   Marginally severe thunderstorms with strong wind gusts and hail will
   be possible Saturday afternoon and evening from parts of the Great
   Lakes southwestward into east-central Missouri, over the northern
   Minnesota vicinity, and over parts of the central and southern High
   Plains.  Locally gusty winds will also be possible across portions
   of the Carolinas and southern Virginia.

   ...Synopsis...
   A large upper ridge will exist over the West, with northwest flow
   from the northern Plains toward the Appalachians. The strongest
   winds aloft will remain over the Northern Plains/Upper MS Valley,
   with strong cooling aloft as the nose of a 100+ kt upper jet dives
   into ND and MN. Meanwhile, a leading wave will depart northeastward
   across Ontario, with a weak front moving across MI, IL, and MO.

   To the east, a weak midlevel trough will approach the Appalachians,
   with only 15-25 kt midlevel southwesterlies across the Mid Atlantic.
   Weak low pressure will develop over the Southeast, and heating will
   occur over GA and SC.

   At the surface, high pressure will exist over the central and
   northern Plains, but another front will affect northern MN during
   the afternoon, providing a focus for storms. The high will also
   provide easterly surface winds over parts of the central Plains, and
   this will maintain 50s F dewpoints into CO and NM, aiding diurnal
   storm potential.

   ...Northern MN...
   Deep-layer shear will be strong Saturday afternoon as the upper jet
   noses southeast. At least isolated storms are likely to form over
   northern MN during the late afternoon along the front. Forecast
   soundings show cool profiles aloft, as well as hodographs favorable
   for supercells capable of large hail. Instability will be sufficient
   for at least marginal hail, and severe coverage may depend on actual
   destabilization as antecedent boundary layer conditions will start
   the day dry. Evapotranspiration will play a role in boundary layer
   moisture quality.

   ...Carolinas vicinity...
   A moist air mass with high RH throughout the column will be in place
   Saturday morning, with scattered showers and thunderstorms over WV,
   VA, and NC. This will likely minimize heating and thus instability
   over much of the area. While low-level winds will have a large
   easterly component, they will be weak in magnitude, and only
   sporadic strong storms are expected where pockets of destabilization
   occur. A slightly greater chance at damaging downbursts may exist
   over southern parts of the area toward SC where heating will be
   better.

   ...From MI into IL and MO...
   Areas of moderate instability may develop ahead of a cold front,
   which will lose forward speed as the upper trough lifts across
   Ontario. While shear will be weak, MLCAPE over 2000 J/kg along with
   steep low-level lapse rates suggest clusters of storms may be
   capable of damaging downbursts or marginal hail.

   ...Central/Southern High Plains...
   Capping will exist for much of the day, but heating will eventually
   erode the cap, revealing a moderately unstable air mass as dewpoints
   remain in the 50s F with easterly surface winds. Storms will form
   from the Front Range southward into NM, and will spread
   east/southeast beneath modest northwest winds aloft. Hail and
   locally damaging wind gusts are expected.

   ..Jewell.. 08/14/2020

   CLICK TO GET WUUS02 PTSDY2 PRODUCT

   NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z