Mesoscale Discussion 1951
NWS Storm Prediction Center Norman OK
0400 PM CDT Fri Aug 11 2023
Areas affected…southeastern MN and western WI
Concerning…Severe Thunderstorm Watch 627…
Valid 112100Z – 112300Z
The severe weather threat for Severe Thunderstorm Watch 627
SUMMARY…The severe weather threat is increasing across WW 627.
Damaging wind gusts and large hail are possible.
DISCUSSION…Multiple strong/severe thunderstorms are ongoing across
the northern periphery of WW 627. Several wind events have been
reported — including a measured 76 mph gust at in Kanabec County
(KJMR) — as well as hailstones up to 2″ in diameter. These storms
have evolved along/just ahead of a cold front and maintained
semi-discrete/supercellular structures for the last couple of hours.
Additional convection initiation is now underway to the southwest of
these damaging storms. The downstream environment is characterized
by MLCAPE around 1500 J/kg and bulk shear around 50 kts. With long
and straight northwesterly hodographs (currently observed at KMPX),
this environment will be favorable for splitting supercell
structures capable of producing severe hail and wind gusts. Both of
these risks should maximize over the Twin Cities metro and the
southeastern vicinity this afternoon. Thereafter, a gradual
transition to a primarily wind threat is expected this evening as
the system congeals along the cold front.
…Please see www.spc.noaa.gov for graphic product…
LAT…LON 44309484 44759493 45279453 45919376 46089292 46009220
45519129 44449075 43419079 43059142 43249268 43729398