National Weather Service United States Department of Commerce
News Headlines

Overview

An unseasonably strong upper-level disturbance interacted with a warm, moist airmass to spark scattered thunderstorms across Southeast Michigan between 3 and 8 pm July 8. These storms became severe across the Saginaw Valley and Thumb regions, with hail up to golf ball size, scattered wind damage, and localized rainfall amounts near 3 inches.  An EF0 tornado occurred near Pinconning.  The storms weakened upon spreading southward, but re-intensified over the western suburbs of Detroit. A concentrated swath of wind damage occurred from western Wayne County through the Downriver area, with numerous reports of trees down.

Radar:

 

Radar Image Radar Image Radar Image
Composite radar loop 2:30 pm to 8:30 pm courtesy Iowa Environmental Mesonet KDTX radar at 3:17 pm during the tornado. 0.5 degree storm-relative velocity (left) and reflectivity (right). Tornado touchdown location shown by red dot. KDTX radar at 7:25 pm during a period of damaging winds. 0.5 degree base velocity (left) and reflectivity (right).

Storm Reports

Image courtesy of Iowa Environmental Mesonet (IEM).  Yellow boxes are severe thunderstorm warnings, red box is a tornado warning, and purple boxes are special marine warnings.  Local Storm Reports (LSR) are also shown plotted on the map. 

 

 

Power outage map from DTE Energy. Up to 70,000 customers lost power.

 

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1011 AM EDT SAT JUL 09 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0300 PM     HAIL             1 NE BENTLEY            43.96N 84.12W 
07/08/2016  E1.75 INCH       BAY                MI   PUBLIC          

0330 PM     TSTM WND DMG     4 N SANFORD             43.73N 84.39W 
07/08/2016                   MIDLAND            MI   911 CALL CENTER 

            TREES DOWN

0338 PM     HAIL             PINCONNING              43.86N 83.96W 
07/08/2016  M0.88 INCH       BAY                MI   TRAINED SPOTTER 

            HEAVY RAIN. BREEZY. HAIL.

0342 PM     TSTM WND DMG     3 NE PINCONNING         43.89N 83.92W 
07/08/2016                   BAY                MI   TRAINED SPOTTER 

            ROOF PEELED OFF, TREES SNAPPED, AND WINDOWS BLOWN OUT

0342 PM     TSTM WND GST     2 ENE PINCONNING        43.87N 83.92W 
07/08/2016  M64.00 MPH       BAY                MI   TRAINED SPOTTER 

            SEVERE WIND AND NICKLE SIZE HAIL

0342 PM     HAIL             S PINCONNING            43.85N 83.97W 
07/08/2016  E1.75 INCH       BAY                MI   PUBLIC          

            MARATHON GAS STATION

0358 PM     HEAVY RAIN       PINCONNING              43.86N 83.96W 
07/08/2016  M1.10 INCH       BAY                MI   PUBLIC          

            OVER AN INCH OF RAIN IN LESS THAN AN HOUR. 

0410 PM     MARINE TSTM WIND 12 NNW BAY PARK         43.81N 83.72W 
07/08/2016  M49.00 MPH       LHZ422             MI   BUOY            

            AT SAGINAW BAY LIGHT 1

0429 PM     HAIL             2 SSE BAY CITY          43.57N 83.87W 
07/08/2016  M1.00 INCH       BAY                MI   PUBLIC          

            VIA FACEBOOK PHOTO

0440 PM     HAIL             BAY CITY                43.59N 83.89W 
07/08/2016  M1.00 INCH       BAY                MI   TRAINED SPOTTER 

0441 PM     TSTM WND DMG     SEBEWAING               43.73N 83.45W 
07/08/2016                   HURON              MI   EMERGENCY MNGR  

            BIG TREES DOWN AND NUMEROUS WIRES DOWN SEBEWAING TO BAY 
            PORT. VIA DISPATCH.

0444 PM     HAIL             BAY CITY                43.59N 83.89W 
07/08/2016  M1.00 INCH       BAY                MI   TRAINED SPOTTER 

0444 PM     TSTM WND DMG     PIGEON                  43.83N 83.27W 
07/08/2016                   HURON              MI   TRAINED SPOTTER 

            LARGE BRANCHES DOWN. WIND GUST ESTIMATED AROUND 50 MPH.

0457 PM     TSTM WND DMG     ARGYLE                  43.56N 82.94W 
07/08/2016                   SANILAC            MI   EMERGENCY MNGR  

            LARGE TREES DOWN BLOCKING ROADS...NUMEROUS POWER LINES 
            DOWN ACROSS N. SANILAC COUNTY.

0510 PM     TSTM WND DMG     PERRY                   42.82N 84.23W 
07/08/2016                   SHIAWASSEE         MI   PUBLIC          

            LARGE BRANCHES AND POWERLINE DOWN

0514 PM     TSTM WND DMG     3 NNE CASS CITY         43.64N 83.16W 
07/08/2016                   TUSCOLA            MI   TRAINED SPOTTER 

            2 FT DIAMETER TREE DOWN AT SCHWEGLER AND DAUS...LIMB ON 
            WIRES AT FORESTVILLE RD AND VAN DYKE

0530 PM     HAIL             VASSAR                  43.37N 83.58W 
07/08/2016  M0.75 INCH       TUSCOLA            MI   PUBLIC          

0550 PM     MARINE TSTM WIND 1 SSE PORT SANILAC      43.42N 82.54W 
07/08/2016  M41.00 MPH       SANILAC            MI   C-MAN STATION   

0600 PM     TSTM WND DMG     KINGSTON                43.41N 83.19W 
07/08/2016                   TUSCOLA            MI   EMERGENCY MNGR  

            LARGE TREES DOWN BLOCKING ROADS. POWER LINES DOWN. VIA 
            TUSCOLA COUNTY DISPATCH. 

0700 PM     HEAVY RAIN       CASS CITY               43.60N 83.18W 
07/08/2016  M2.65 INCH       TUSCOLA            MI   CO-OP OBSERVER  

            2.5 HOUR TOTAL

0700 PM     TSTM WND DMG     SALEM                   42.41N 83.58W 
07/08/2016                   WASHTENAW          MI   LAW ENFORCEMENT 

            8 INCH DIAMETER TREE DOWN BLOCKING ROAD AT CHUBB AND 6 
            MILE.

0700 PM     HEAVY RAIN       VASSAR                  43.37N 83.58W 
07/08/2016  M1.09 INCH       TUSCOLA            MI   CO-OP OBSERVER  

            2.5 HOUR TOTAL

0702 PM     TSTM WND DMG     5 NNW CANTON            42.38N 83.53W 
07/08/2016                   WAYNE              MI   PUBLIC          

            NUMEROUS TREES AND LIMBS DOWN AT RIDGE AND N TERRITORIAL 
            IN PLYMOUTH TWP

0707 PM     TSTM WND GST     4 E YPSILANTI           42.24N 83.54W 
07/08/2016  M46.00 MPH       WAYNE              MI   ASOS            

            AT WILLOW RUN AIRPORT /KYIP/

0707 PM     HAIL             MANCHESTER              42.15N 84.04W 
07/08/2016  M0.75 INCH       WASHTENAW          MI   TRAINED SPOTTER 

            M52 AND BETHEL CHURCH

0708 PM     TSTM WND DMG     5 SSE CANTON            42.25N 83.45W 
07/08/2016                   WAYNE              MI   PUBLIC          

            LARGE DEAD BRANCHES DOWN AT HAGGERTY AND ECORSE IN VAN 
            BUREN TWP

0710 PM     HAIL             7 NW MANCHESTER         42.22N 84.13W 
07/08/2016  M0.50 INCH       JACKSON            MI   TRAINED SPOTTER 

            HALF INCH HAIL AND HEAVY DOWN POUR...CORNER OF JACOB AND 
            WALKER. 

0715 PM     TSTM WND DMG     WESTLAND                42.32N 83.38W 
07/08/2016                   WAYNE              MI   BROADCAST MEDIA 

            REPORTS OF NUMEROUS TREES DOWN

0715 PM     TSTM WND DMG     WESTLAND                42.32N 83.38W 
07/08/2016                   WAYNE              MI   TRAINED SPOTTER 

            LARGE TREE...APPROX. 17 INCH DIAMETER...UPROOTED

0715 PM     TSTM WND DMG     WESTLAND                42.32N 83.38W 
07/08/2016                   WAYNE              MI   AMATEUR RADIO   

            GAS STATION CANOPY COLLAPSED ON TOP OF CARS

0721 PM     TSTM WND GST     2 ENE ROMULUS           42.23N 83.33W 
07/08/2016  M56.00 MPH       WAYNE              MI   ASOS            

            AT DETROIT METRO AIRPORT /KDTW/

0725 PM     HEAVY RAIN       6 WNW SANDUSKY          43.46N 82.93W 
07/08/2016  M2.70 INCH       SANILAC            MI   TRAINED SPOTTER 

0726 PM     TSTM WND DMG     TAYLOR                  42.23N 83.27W 
07/08/2016                   WAYNE              MI   PUBLIC          

            TREES UP TO 1 FOOT DIAMETER SNAPPED. NUMEROUS MEDIUM TO 
            LARGE BRANCHES DOWN.

0727 PM     TSTM WND DMG     3 E TAYLOR              42.23N 83.22W 
07/08/2016                   WAYNE              MI   TRAINED SPOTTER 

            ALLEN PARK...REECK AND GODDARD...LARGE TREES DOWN OVER A 
            FOOT IN DIAMETER. POWER OUT. FOUR HOMES IN A ROW WITH 
            LARGE TREES DOWN. TREES BLOCKING ROAD.

0728 PM     TSTM WND DMG     2 ESE TAYLOR            42.21N 83.23W 
07/08/2016                   WAYNE              MI   PUBLIC          

            TREES SNAPPED AND UPROOTED

0730 PM     TSTM WND DMG     RIVERVIEW               42.17N 83.19W 
07/08/2016                   WAYNE              MI   PUBLIC          

            POWER LINES DOWN. POWER POLE DOWN ACROSS FORT STREET JUST
            SOUTH OF PENNSYLVANIA ROAD.

0730 PM     TSTM WND GST     4 ENE ROMULUS           42.25N 83.29W 
07/08/2016  E65.00 MPH       WAYNE              MI   TRAINED SPOTTER 

            WIND SPEED ESTIMATED AT 65 MPH...HAIL ESTIMATED AT 1 
            INCH.

0730 PM     TSTM WND DMG     DEARBORN                42.31N 83.21W 
07/08/2016                   WAYNE              MI   TRAINED SPOTTER 

            TOP OF LARGE TREE...18 INCH DIAMETER...BLOWN OFF IN 
            STRONG WIND....ON MORLEY.

0730 PM     TSTM WND DMG     RIVERVIEW               42.17N 83.19W 
07/08/2016                   WAYNE              MI   PUBLIC          

            POWER LINES DOWN ON RIVERVIEW STREET AND WEST JEFFERSON

0730 PM     TSTM WND DMG     WYANDOTTE               42.21N 83.16W 
07/08/2016                   WAYNE              MI   PUBLIC          

            LARGE TREE LIMBS DOWN AT 16TH AND PINE STREETS...ALSO 
            SEVERAL TREES DOWN AT 17TH AND ORCHARD STREETS. 

0734 PM     HAIL             SOUTHGATE               42.20N 83.21W 
07/08/2016  E0.75 INCH       WAYNE              MI   TRAINED SPOTTER 

            WIND ESTIMATED AT 60 MPH...LAMP POSTS WAVERING. 
            INTERSECTION OF EUREKA AND CLINTON RD. 

0735 PM     TSTM WND DMG     3 SE TAYLOR             42.20N 83.23W 
07/08/2016                   WAYNE              MI   TRAINED SPOTTER 

            LARGE LIMBS DOWN...DOWNED POWER LINES...MAJOR PONDING ON 
            ROADWAYS...ALLEN RD AND EUREKA RD

0736 PM     HAIL             RIVERVIEW               42.17N 83.19W 
07/08/2016  E1.75 INCH       WAYNE              MI   TRAINED SPOTTER 

            HAIL EST. WIND EST. AT 60 MPH. TORRENTIAL DOWNPOUR. 
            INTERSECTION OF HALE AND FORT RD.

0800 PM     HEAVY RAIN       DECKERVILLE             43.53N 82.74W 
07/08/2016  M2.25 INCH       SANILAC            MI   TRAINED SPOTTER 

            3 HOUR TOTAL

 


Rain Reports

Radar estimated precipitation

 

Public Information Statement...Storm Totals
National Weather Service Detroit/Pontiac MI
1011 AM EDT Sat Jul 9 2016


STORM TOTAL HEAVY RAIN REPORTS

Location                   Precip      Duration
                          (Inches)      (Hours)        Lat       Lon

...Bay County...
   Pinconning              M  1.10            M     43.86N    83.96W

...Sanilac County...
   Deckerville             M  2.25            3     43.53N    82.74W
   6 WNW Sandusky          M  2.70            M     43.46N    82.93W


M = Measured
E = Estimated

Environment

A warm and moist airmass was in place over Southeast Michigan on July 8, as temperatures warmed into the upper 80s with dewpoints near 70.  At upper levels, an unseasonably strong upper low moved across Lake Superior during the day (Figs. 1 and 2).  Storms were triggered along a surface cold front that moved eastward across Michigan (Fig. 3), with upward motion enhanced as upper-level height falls worked into the region.
 
The 18Z DTX sounding sampled an environment that was favorable for severe weather (Fig. 4).  Strong flow at 500 mb around the southern periphery of the upper low resulted in effective bulk shear values near 50 knots (Fig. 5), favorable for organized thunderstorms.  This shear, along with adequate CAPE in the hail growth zone, moderately steep mid-level lapse rates, and dry air in the mid levels, supported hail production.  Lengthy hodographs supported rotating cells, especially over the Saginaw Valley early in the event.  Backed surface winds in the area also contributed to rotating updrafts.  The atmosphere was less favorable for hail southward toward Metro Detroit further from the upper low, but instability with MLCAPE approaching 2500 J/kg supported strong updrafts which were favorable for severe winds as cold pools developed.  DCAPE values of up to 1400 J/kg illustrated the potential for negative buoyancy (Fig. 6).  One aspect of the 18Z sounding that was less favorable for severe weather was the layer of warm air between roughly 850 and 750 mb.  While not a stout cap, this layer may have been just deep enough to impede updrafts and allow for a more limited severe weather threat south of I-69.

 

Environment Environment Environment Environment
Figure 1: SPC mesoanalysis of 500 mb heights and winds valid 18Z Figure 2: Water vapor imagery valid 18Z (courtesy NCAR) Figure 3: Surface observations and WPC analysis valid 19Z Figure 4. 18Z DTX sounding

 

Environment Environment
Figure 5: SPC mesoanalysis of MUCAPE and effective bulk shear valid 19Z Figure 6: SPC mesoanalysis of DCAPE 20Z

nws logo Media use of NWS Web News Stories is encouraged!
Please acknowledge the NWS as the source of any news information accessed from this site.
nws logo