SPC MD 1145

MD 1145 CONCERNING SEVERE THUNDERSTORM WATCH 344... FOR CENTRAL MINNESOTA INTO NORTHEAST SOUTH DAKOTA.

Mesoscale Discussion 1145
NWS Storm Prediction Center Norman OK
0617 PM CDT Wed Jul 08 2020

Areas affected...central Minnesota into northeast South Dakota.

Concerning...Severe Thunderstorm Watch 344...

Valid 082317Z - 090115Z

The severe weather threat for Severe Thunderstorm Watch 344
continues.

SUMMARY...The severe threat will continue for WW 344 for the next
1-2 hours. Primary threats will be hail and strong winds, but a
localized tornado threat may persist for the near term.

DISCUSSION...A single supercell with multiple tornado reports has
been ongoing over the past hour across west-central MN. This
supercell has developed along a warm frontal zone where strong
veering between 925 to 700 mb has compensated for relatively weak
near-surface winds. Although this specific cell has shown recent
signs of weakening, it remains fairly isolated within an environment
supportive of severe convection (effective bulk wind shear between
25-30 knots and 3000-4000 J/kg MLCAPE). As such, a
re-intensification is possible. Attempts at additional convective
initiation to the east of this supercell have been noted, but have
failed so far. However, cumulus in this area continues to show
agitation, suggesting that additional attempts at CI are possible
within the next 1-2 hours. If this occurs, the tornado threat should
be relatively low due to decreasing ESRH with eastward extent, but
can not be ruled out entirely if an isolated discrete storm can
become rooted along the warm front. Regardless, a hail and wind
threat should accompany any storm developing within this region.

To the northeast of this area, isolated to scattered elevated
semi-discrete convection will continue to pose a threat for severe
hail and strong winds. Increasing shear over the next one to two
hours with the approach of stronger upper-level winds may lead to a
more robust, but possibly isolated, severe threat. Storm development
along a trailing surface trough/stationary boundary across northeast
South Dakota remains likely over the next few hours.

..Moore.. 07/08/2020

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

ATTN...WFO...DLH...MPX...FGF...FSD...ABR...

LAT...LON   46049654 46879611 47519467 48029279 47959141 46979053
            46509041 46049073 45609189 45079353 44949547 44619639
            44429722 44649747 45489688 46049654 

Read more

from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1145.html