SPC AC 200555

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1255 AM CDT Mon Aug 20 2018

   Valid 211200Z - 221200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE
   NORTH-CENTRAL APPALACHIANS/MID-ATLANTIC STATES AND THE SOUTH-CENTRAL
   HIGH PLAINS...

   ...SUMMARY...
   Severe thunderstorms will be possible on Tuesday, especially during
   the afternoon and evening across portions of the
   Appalachians/Mid-Atlantic States as well as the south-central High
   Plains.

   ...Appalachians/Upper Ohio River Valley and Mid-Atlantic States...
   Although the primary surface cyclogenesis will be focused north of
   the International border, a semi-amplified belt of seasonally
   strong/cyclonically curved westerlies will overspread much of the
   region on Tuesday coincident with an eastward-moving cold front.
   Relatively widespread early-day convection and lingering cloud cover
   limits confidence in appreciable destabilization and may somewhat
   curb the overall magnitude of Tuesday's severe risk.

   However, relatively strong low-level shear and upwards of 35-40 kt
   effective shear suggests the potential for sustained multicells and
   some supercells where adequate (even modest) diurnally enhanced
   destabilization occurs Tuesday afternoon. This currently appears
   most probable across far eastern Ohio/western Pennsylvania southward
   into parts of Maryland/Virginia. Elsewhere, at least isolated severe
   storms may occur as far south as the Carolinas/southern Appalachians
   under a more modestly strong flow regime.

   ...South-Central High Plains...
   Moist low-level upslope flow will be focused on Tuesday to the north
   of a southern High Plains surface low. This will be in  conjunction
   with a moderately strong (25-30 kt at 500 mb) belt of westerlies to
   the north of the southern High Plains-centered upper-level ridge.
   While initial storm development Tuesday afternoon is expected over
   the Front Range/foothills vicinities, it appears a sub-regional area
   of more favorable deep-layer shear and buoyancy coincident with
   probable storm development will exist across far southeast Colorado
   and neighboring areas including far southwest Kansas and the western
   Oklahoma Panhandle. Both severe-caliber wind gusts and hail will be
   possible across the region.

   ...MAXIMUM RISK BY HAZARD...
   Tornado:   5%     - Slight
   Wind:     15%     - Slight
   Hail:     15%     - Slight

   ..Guyer.. 08/20/2018

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