Probability of a tornado within 25 miles of a point. Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
No Risk Areas Forecast
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.
Day 1 Wind Risk
Area (sq. mi.)
Area Pop.
Some Larger Population Centers in Risk Area
15 %
21,618
3,829,646
Minneapolis, MN...St. Paul, MN...Bloomington, MN...Plymouth, MN...Brooklyn Park, MN...
SPC AC 220106
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0806 PM CDT Fri Aug 21 2020
Valid 220100Z - 221200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER MISSISSIPPI VALLEY...
...SUMMARY...
Severe storms with large hail and damaging winds are possible this
evening across parts of southern Minnesota. A few strong storms may
also impact parts of northern Wisconsin and Upper Michigan.
...Upper Mississippi Valley/Western Great Lakes...
The latest water vapor imagery shows a west-northwest mid-level flow
pattern from the northern Plains into the Great Lakes with a subtle
shortwave trough over the upper Mississippi Valley. At the surface,
a moist airmass is in place from the eastern Dakotas into southern
Minnesota where dewpoints are in the 70s F. This is contributing to
strong instability with the RAP estimating MLCAPE in the 3000 to
4000 J/kg range from eastern South Dakota into western Minnesota. A
cluster of thunderstorms is located near a maximum of instability in
southwest Minnesota and is just ahead of the shortwave trough. In
addition, regional WSR-VWPs show 0-6 km shear in the 20 to 25 kt
range. The Minneapolis 00Z soundings has steep lapse rates in the
low to mid-levels. These conditions combined with the strong
instability will support a severe threat this evening. As the
cluster of storms moves east-southeastward across southern Minnesota
this evening, isolated large hail and wind damage can be expected
along the leading edge and within the more intense cores.
Further to the east, a line segment is ongoing in northern Wisconsin
and western Upper Michigan. This line is located near a maximum of
instability with the RAP estimating MLCAPE near 2000 J/kg. Although
deep-layer shear is estimated to be around 20 kt, the 00Z sounding
at Green Bay has a 7.3 C/km lapse rate from 0 to 3 km. This may be
enough for a few marginally severe wind gusts along the leading edge
of the line early this evening. Hail could also accompany the
stronger updrafts.
..Broyles.. 08/22/2020
CLICK TO GET WUUS01 PTSDY1 PRODUCT
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z
| 
)
