Mesoscale Discussion 1445
NWS Storm Prediction Center Norman OK
0458 PM CDT Fri Jul 12 2019
Areas affected...Portions of northern/central WI into western Upper
Concerning...Severe potential...Watch possible
Valid 122158Z - 122330Z
Probability of Watch Issuance...40 percent
SUMMARY...Isolated, marginally severe hail will continue to be
possible with storms this evening. Although watch issuance remains
possible, it is not immediately likely.
DISCUSSION...Convection that has developed along/ahead of a cold
front this afternoon across northern WI into western portions of
Upper MI has struggled to reach severe intensities. This may be
related to modest (6-6.5 C/km) mid-level lapse rates present over
this region per RAP forecast soundings, and some storms remaining
slightly elevated across northeastern WI and adjacent Upper MI.
Still, a favorable combination of 1000-1500 J/kg of MLCAPE and 40-45
kt of effective bulk shear will continue to support some updraft
organization, with marginally severe hail the main threat.
Instability quickly lessens with eastward extent into eastern WI and
central/eastern portions of Upper MI where dewpoints are only in the
mid 40s to upper 50s. Any storms that move eastward into this less
favorable environment should quickly weaken. At this point, watch
issuance remains possible late this afternoon/evening, but does not
appear immediately likely due to observed radar trends, small
spatial threat area, and modest lapse rates described previously.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 46399044 46278852 46148752 45958704 45758691 45388683
44728729 44398760 44378883 44628987 45079035 45599057