010
ACUS11 KWNS 180151
SWOMCD
SPC MCD 180151
MIZ000-180415-

Mesoscale Discussion 1644
NWS Storm Prediction Center Norman OK
0851 PM CDT Fri Jul 17 2026

Areas affected...Northern Lower Michigan

Concerning...Severe potential...Watch unlikely

Valid 180151Z - 180415Z

Probability of Watch Issuance...20 percent

SUMMARY...An approaching thunderstorm cluster will pose a risk of
damaging wind gusts as it moves into northern Lower Michigan over
the next couple of hours.

DISCUSSION...The latest radar data from KAPX shows a loosely
organized thunderstorm cluster tracking southeastward from eastern
Upper MI and northern Lake MI, with additional cells developing
along the southern and western flanks. Over the next couple of
hours, this activity should continue tracking southeastward along a
buoyancy gradient extending into northern Lower MI. Here, the APX
00Z sounding sampled an elongated hodograph (around 45 kt of
effective shear) with modest low-level hodograph curvature (210
m2/s2 effective SRH) and around 800 J/kg MLCAPE. Given the
established cold pool and continued upscale growth, this downstream
environment should support the maintenance of this thunderstorm
cluster into northern Lower MI. The primary concern will be damaging
wind gusts, though isolated severe hail will also be possible. Given
the localized nature of the risk, a watch is not expected.

..Weinman/Hart.. 07/18/2026

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

ATTN...WFO...APX...

LAT...LON   45658524 45818502 45848462 45758395 45478353 45178337
            44778358 44608394 44588454 44778513 45288544 45658524

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN