SPC MD 1421

MD 1421 CONCERNING SEVERE THUNDERSTORM WATCH 420... FOR EAST-CENTRAL MINNESOTA AND ADJACENT NORTHWESTERN WISCONSIN

Mesoscale Discussion 1421
NWS Storm Prediction Center Norman OK
1125 PM CDT Fri Aug 07 2020

Areas affected...east-central Minnesota and adjacent northwestern
Wisconsin

Concerning...Severe Thunderstorm Watch 420...

Valid 080425Z - 080600Z

The severe weather threat for Severe Thunderstorm Watch 420
continues.

SUMMARY...Local severe risk persists with one or two of the more
intense/remaining storms, but will continue to gradually diminish
over the next 1 to 2 hours.

DISCUSSION...Latest radar loop shows a small cluster of storms
persisting in conjunction with the continued eastward advance of a
well-defined mesoscale circulation/MCV, now approaching the
Arrowhead region of Minnesota.  Instability diminishes steadily
downstream from the ongoing storms into Wisconsin and western Lake
Superior, which suggests a continued decrease in convective
intensity.  The strongest storms remain now on the southern and
southwestern flanks of the MCV circulation, where greater
instability is combining with a southwesterly low-level-jet-induced
zone of warm advection to yield this favored zone of persistent
convective redevelopment.

With that said, as the system shifts eastward with time, and capping
continues to increase with respect to surface-based parcels, storms
will continue to weaken and trend toward becoming more elevated. 
This suggests that the notable decrease in convective intensity
which has occurred over the past hour will continue, and should
preclude any need for a new WW beyond the scheduled 06Z expiration
of WW 420.

..Goss.. 08/08/2020

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

ATTN...WFO...DLH...MPX...FGF...

LAT...LON   46909410 46739196 45469206 45159304 45309468 46399482
            46909410 

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