396  
ACUS11 KWNS 202215  
SWOMCD  
SPC MCD 202215  
MIZ000-WIZ000-210015-  
 
MESOSCALE DISCUSSION 1677  
NWS STORM PREDICTION CENTER NORMAN OK  
0515 PM CDT MON JUL 20 2026  
 
AREAS AFFECTED...WESTERN U.P. OF MICHIGAN  
 
CONCERNING...TORNADO WATCH 501...  
 
VALID 202215Z - 210015Z  
 
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 501 CONTINUES.  
 
SUMMARY...THE THREAT FOR A FEW TORNADOES APPEARS TO BE INCREASING  
ACROSS THE DISCUSSION AREA.  
 
DISCUSSION...OVER THE PAST HOUR, SEVERAL DISCRETE SUPERCELLS HAVE  
DEVELOPED OVER THE WESTERN U.P. OF MI WITHIN A MOIST AND MODERATE  
ENVIRONMENT WITH MLCAPE AS HIGH AS 2500-3000 J/KG, PER LATEST  
OBJECTIVE ANALYSIS. THE KMQT VWP CURRENTLY RESIDES WITHIN THE  
EASTERN FRINGE OF STRONGER INSTABILITY, WHERE LOCALLY BACKED  
NEAR-SURFACE WINDS ARE RESULTING IN RELATIVELY STRONG LOW-LEVEL AND  
DEEP-LAYER SHEAR WITH 0-1 KM SRH OF OVER 200 M2/S2 AND 0-6 KM SHEAR  
OF 50 KT, RESPECTIVELY.  
 
CURRENT RADAR OBSERVATIONS INDICATE THE SUPERCELLS MATURING NEAR THE  
EASTERN EDGE OF GREATER INSTABILITY (AROUND THE LONGITUDE OF  
MARQUETTE) AND WITHIN THE ZONE OF ENHANCED VERTICAL SHEAR.  
NON-HYDROSTATIC PRESSURE PERTURBATIONS EXISTING WITH THE ONGOING  
SUPERCELLS WILL SUSTAIN THE STORMS FARTHER EAST INTO THE CENTRAL  
U.P.; HOWEVER, THE TORNADO THREAT MAY BE MUTED BY THE HIGHER  
CONVECTIVE INHIBITION WITH EASTWARD EXTENT, AT LEAST IN THE SHORT  
TERM.  
 
AS OF 2205Z, THE BEST TORNADO POTENTIAL APPEARS TO EXIST WITH THE  
SUPERCELLS NEAR THE MI-WI STATE LINE, NORTHWEST OF IRON MOUNTAIN,  
AND OVER FAR NORTHEAST DICKINSON AND SOUTHEAST MARQUETTE COUNTIES.  
IN ADDITION TO THE TORNADO THREAT, THE POTENTIAL WILL EXIST FOR  
LARGE HAIL WITH THE STRONGEST SUPERCELLS.  
 
..MEAD.. 07/20/2026  
   
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT  
 
ATTN...WFO...MQT...GRB...  
 
LAT...LON 46108986 46498971 46738899 46718797 46608687 46208660  
45658678 45528777 45488871 45638936 45818975 46108986  
 
MOST PROBABLE PEAK TORNADO INTENSITY...120-145 MPH  
MOST PROBABLE PEAK WIND GUST...55-70 MPH  
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN  
CLICK HERE TO GO TO PREVIOUS BULLETINS.
The Nexlab SPC Page
Main Text Page