Mesoscale Discussion 1644
Issued: · Valid: –
Summary
A cluster of thunderstorms moving into northern Lower Michigan over the next few hours may produce damaging wind gusts and isolated severe hail.
Product Text
000 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