SPC Jul 16, 2020 0730 UTC Day 3 Severe Thunderstorm Outlook

SPC 0730Z Day 3 Outlook

Day 3 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0236 AM CDT Thu Jul 16 2020

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN
MN...NORTHERN/CENTRAL WI AND PORTIONS OF THE UPPER PENINSULA OF
MI...

CORRECTED FOR TEXT IN FIRST PARAGRAPH

...SUMMARY...
Strong to severe storms are possible on Saturday across portions of
the Upper Midwest and Great Lakes vicinity. Damaging wind gusts
appear to be the main hazard with these storms.

...Upper Midwest/Great Lakes...

Convection will likely be ongoing across portions of northern MN/WI
and the Upper Peninsula of MI at the beginning of the period as an
MCS from the Day 2 period shifts east/northeast in tandem with a
compact shortwave impulse. A larger-scale upper trough over the
northern Rockies early Saturday will progress eastward across the
northern Plains to the upper MS Valley by Sunday morning. At the
surface, low pressure near the Manitoba/Ontario border will develop
eastward, and a cold front will shift east/southeast across the
northern Plains, extending from the MN/WI border southwestward to
the NE/KS border by Sunday morning. 

While some uncertainty exists due to aforementioned convection on
Day 2 continuing into the early Day 3 period, most guidance suggest
a very moist and unstable airmass will reside to the south of
whatever outflow reside across northern MN/WI. As ascent increases
across the region with the approach of the main upper trough,
thunderstorms are expected to develop near the cold front and
residual outflow. Strong instability, steep lapse rates, and a
modest low level jet should support at least widely scattered,
organized severe thunderstorms tracking east/southeast along a
strong instability gradient across the upper MS Valley and Great
Lakes vicinity. Damaging wind appears to be the main threat with
this activity, but hail and a couple tornadoes would also be
possible with any discrete cells.

..Leitman.. 07/16/2020

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from SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day3otlk_0730.html