802
ACUS03 KWNS 190722
SWODY3
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

$$