SPC AC 190722

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0222 AM CDT Wed Jun 19 2024

   Valid 211200Z - 221200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER A SMALL
   PART OF THE NORTHEAST...AND ACROSS THE NORTHERN PLAINS...

   ...SUMMARY...
   Scattered strong to severe storms will be possible over the northern
   Plains to upper Mississippi Valley on Friday, with a few strong
   storms over parts of the Northeast.

   ...Synopsis...
   On Friday, a strong upper ridge will remain over the eastern CONUS,
   but will begin to retrograde toward the MS Valley and southern
   Plains late in the period. Meanwhile, the upper trough over the
   Great Basin will eject northeastward across the northern Rockies
   during the day, with cooling aloft and 40 kt midlevel winds over MT
   through 00Z. This wave will continue across the northern Plains and
   toward the upper MS Valley into Saturday morning, with increasing
   winds aloft north of the upper ridge. Moderate west/northwest flow
   aloft will develop across New England, as the eastern Canada trough
   rounds the upper ridge.

   At the surface, high pressure will exist over the Southeast and into
   the southern Plains, with a warm front lifting north across the
   upper MS Valley. Weak low pressure will exist from WY into NE during
   the day, moving in to MN overnight with a front/wind shift across
   the Dakotas. The warm sector there will favor strong storms as
   instability develops ahead of the upper wave. To the east, a weak
   front will drop south across southern New England into PA, providing
   a focus for daytime thunderstorms as the air mass remains unstable.

   ...Upper MS Valley...
   Daytime heating and moisture advection will result in
   destabilization across the northern Plains south of the warm front.
   Southerly winds will increase during the day over NE and SD near the
   surface low, with strengthening convergence as the cold front
   arrives from the west overnight. A few strong elevated storms could
   produce marginal hail over northern MN north of the warm front, but
   the greatest severe potential will develop during the late afternoon
    from western NE into SD. Shear will not be particularly strong but
   it will be sufficient to support a few cells capable of hail, with
   increasing wind damage potential through the evening as the trough
   continues east. A Slight Risk may be needed in later updates as
   predictability increases.

   ...Northeast...
   A moist and unstable air mass will remain across the area south of a
   front, which may be reinforced by residual outflow or early-day
   showers/thunderstorms. Gradual height falls will occur during the
   day over the region as the upper ridge shifts west, with strong
   heating expected across OH and PA. Shear will again be weak but
   diurnal storms may produce locally strong or damaging gusts from
   portions of PA eastward into southern New England.

   ..Jewell.. 06/19/2024

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z