3DVAR indicates thunderstorm strengthening

The 3DVAR products indicated strengthening of this thunderstorm with both the updraft helicity and maximum updraft values spiking on the 2140z image. This thunderstorm had previously caused wind damage (downed power poles) across southern FIllmore county. The values at 2140z were higher than those previously (as shown by underlaid history tracks) so a severe thunderstorm warning was issued for the potential for strong damaging winds.

UPDATE: Emergency managers reported widespread tree damage within the community of Winona, in the northern portion of the warned area, a lead time of 17 minutes. Dime sized hail was also reported within the warned area in southeastern Winona County.