SPC MD 1716

MD 1716 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF WISCONSIN INTO UPPER MICHIGAN

Mesoscale Discussion 1716
NWS Storm Prediction Center Norman OK
0307 PM CDT Sat Sep 26 2020

Areas affected...Portions of Wisconsin into upper Michigan

Concerning...Severe potential...Watch possible 

Valid 262007Z - 262130Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms will continue to increase in coverage across
portions of central Wisconsin with the potential for large to very
large hail with the strongest storms as they move into upper
Michigan into the evening. A Severe Thunderstorm Watch may be
needed.

DISCUSSION...Satellite, radar, and lightning trends over the past
hour have shown thunderstorms increasing in coverage/intensity over
portions of central Wisconsin where RAP mesoanalysis places the
leading edge of a northward-advancing instability axis. While the
evolution of this activity over the next few hours is somewhat
uncertain, owing in part to lack of recent model support and poor
instability (generally less than 500 j/kg) over the area due to
persistent cloud cover, very strong effective bulk shear (e.g., > 50
knots sampled by area VADs) suggests any storm that can become
organized could become supercellular with the large (to very large)
hail being the primary hazard due to the elevated nature of the
activity.

A Severe Thunderstorm Watch may be needed over the next hour or so
if storms can become well established/organized.

..Elliott/Grams.. 09/26/2020

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

ATTN...WFO...APX...MQT...GRB...DLH...ARX...MPX...

LAT...LON   45969009 46408774 46248614 45708574 44928604 44628721
            44268825 44088956 44599105 45449103 45969009 

Read more

from SPC Forecast Products http://www.spc.noaa.gov/products/md/md1716.html