Milwaukee, WI...Madison, WI...Sioux Falls, SD...Green Bay, WI...Duluth, MN...
Probabilistic Damaging Wind Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
SPC AC 171739
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1239 PM CDT Fri Jul 17 2020
Valid 181200Z - 191200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER A PORTION OF
THE UPPER MIDWEST AND GREAT LAKES REGION...
...SUMMARY...
Scattered severe storms should occur Saturday across portions of the
Upper Midwest and Great Lakes vicinity. Damaging winds and large
hail appear to be the main hazards with these storms, some of which
could be significant. A few tornadoes are also possible.
...Upper Midwest through Great Lakes areas...
An MCS will likely be ongoing over a portion of the Great Lakes
region, most likely from upper MI into WI, with trailing outflow
boundary extending farther southwest into southern MN. Meanwhile,
farther upstream, a progressive shortwave trough will reside over
the northern Plains with accompanying cold front likely extending
from eastern ND southwestward through western SD. This front will
continue east and likely extend from northern MN through eastern SD,
central NE into northeast CO by early afternoon. The atmosphere in
vicinity of and south of the outflow boundary and east of the cold
front will likely once again become very unstable with 3000-4000
J/kg MLCAPE supported by rich low-level moisture and steep lapse
rates. Initial thunderstorms will most likely develop near
intersection of the cold front and remnant outflow boundary from
southeast SD into southwest MN. This region will reside within belt
of stronger mid-level winds supporting 35-40 kt effective bulk
shear. Discrete supercells will be likely with a threat for large to
very large hail and a few tornadoes possible as well. Eventually
storms should evolve into an organized MCS with an increasing threat
for damaging wind, some of which could be significant.
Considerable uncertainty still exists regarding where tonight's MCS
and outflow boundary will have the most impact on Saturday's
pre-storm environment. Will therefore leave as SLGT risk for now.
However, an upgrade to enhanced will probably be needed for a
portion of this region in upcoming day 1 outlooks.
..Dial.. 07/17/2020
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z
| 
)
