SPC MD 1543

MD 1543 CONCERNING SEVERE THUNDERSTORM WATCH 447... FOR PARTS OF SOUTHEASTERN MINNESOTA INTO WEST CENTRAL WISCONSIN

Mesoscale Discussion 1543
NWS Storm Prediction Center Norman OK
0954 PM CDT Fri Aug 21 2020

Areas affected...Parts of southeastern Minnesota into west central
Wisconsin

Concerning...Severe Thunderstorm Watch 447...

Valid 220254Z - 220500Z

The severe weather threat for Severe Thunderstorm Watch 447
continues.

SUMMARY...Strong, to perhaps locally severe, wind gusts will remain
possible across and southwest of the Greater Minneapolis
metropolitan area through 10-11 PM, before thunderstorms begin to
weaken more substantively.  It appears unlikely that a new watch
will be needed farther east.

DISCUSSION...A compact, but organized, mesoscale convective system
continues to approach the Minneapolis metro and areas to the
southwest.  The leading edge of the outflow surged out ahead of the
stronger leading line of storms, but the distance has been
maintained at about 5-10 miles for about the past hour or so.  The
stronger convection has largely maintained intensity, but peak
measured surface gusts to this point have generally only approached
severe limits.

Into the 03-04Z time frame, the gust front will overspread the
Minneapolis metro area.  However, it appears that the strongest
continuing thunderstorm development may tend to propagate near or
just southwest through south of the metropolitan area, aided by weak
warm advection along a residual low-level baroclinic zone.  Even
this activity seems likely to gradually diminish in intensity
shortly thereafter, as system inflow tends to become less unstable 
across far southeastern Minnesota and western Wisconsin.

..Kerr.. 08/22/2020

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DLH...ARX...MPX...

LAT...LON   45719370 45669231 45049157 44429185 43679295 43779403
            44239471 44849372 45719370 

Read more

from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1543.html