Severe Weather September 11, 2013

A cold front, interacting with unseasonably warm and moist air, triggered a round of showers and thunderstorms across southeast Michigan during the afternoon and evening hours of September 11.  Temperatures were in the upper 80s and low 90s ahead of the front.  The warm temperatures, combined with relatively high dewpoints, gave the storms plenty of instability to work with.  A Severe Thunderstorm Watch was issued at 4:40 PM EDT.  Storms moved into the DTX County Warning Area around 5:00 PM, and the first Severe Thunderstorm Warning was issued at 5:20 PM.  The storms continued across southeast Michigan before weakening and exiting by around 8:00 PM.  Damaging winds were the main threat with the storms.

Radar (courtesy of Iowa Environmental Mesonet)

Local Storm Reports (courtesy of Iowa Environmental Mesonet)

 PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
926 PM EDT WED SEP 11 2013

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

0530 PM     TSTM WND DMG     2 SSE GRAND BLANC       42.90N 83.60W 
09/11/2013                   GENESEE            MI   TRAINED SPOTTER 

            12 INCH DIAMETER TREE DOWN. ALSO DIME-SIZED HAIL. TIME 
            ESTIMATED FROM RADAR.

0605 PM     TSTM WND DMG     4 SSE OXFORD            42.77N 83.21W 
09/11/2013                   OAKLAND            MI   911 CALL CENTER 

            TREES DOWN. TIME ESTIMATED FROM RADAR

0605 PM     TSTM WND DMG     PONTIAC                 42.65N 83.29W 
09/11/2013                   OAKLAND            MI   911 CALL CENTER 

            UTILITY POLE DOWN AT WOODWARD AND RAPID. CORRECTED FOR 
            TIME.

0605 PM     TSTM WND DMG     5 NE STOCKBRIDGE        42.50N 84.11W 
09/11/2013                   LIVINGSTON         MI   911 CALL CENTER 

            TREES DOWN. TIME ESTIMATED FROM RADAR.

0611 PM     TSTM WND DMG     3 SSE LAKEVILLE         42.78N 83.14W 
09/11/2013                   OAKLAND            MI   911 CALL CENTER 

            TREES DOWN. TIME ESTIMATED FROM RADAR.

0615 PM     TSTM WND DMG     PINCKNEY                42.45N 83.95W 
09/11/2013                   LIVINGSTON         MI   911 CALL CENTER 

            TREES DOWN BETWEEN UNADILLA AND HAMBURG. TIME ESTIMATED 
            FROM RADAR.

0615 PM     TSTM WND DMG     6 E OXFORD              42.83N 83.14W 
09/11/2013                   OAKLAND            MI   911 CALL CENTER 

            TREE DOWN AT ROCHESTER AND LAKEVILLE SOUTH OF LEONARD. 
            TIME ESTIMATED FROM RADAR.

0623 PM     TSTM WND DMG     2 E ROCHESTER           42.68N 83.08W 
09/11/2013                   MACOMB             MI   TRAINED SPOTTER 

            12 INCH DIAMETER TREE LIMBS DOWN ON 24 MILE BETWEEN 
            SHELBY AND DEQUINDRE ROADS. RADAR ESTIMATED TIME.

0630 PM     TSTM WND DMG     HOWELL                  42.61N 83.94W 
09/11/2013                   LIVINGSTON         MI   911 CALL CENTER 

            TREES DOWN AT CHILSON AND GRAND RIVER. TIME ESTIMATED 
            FROM RADAR.

0630 PM     TSTM WND DMG     2 N COMMERCE            42.62N 83.49W 
09/11/2013                   OAKLAND            MI   AMATEUR RADIO   

            3 INCH DIAMETER TREE DOWN/ HEAVY RAIN...1 INCH. TIME IS 
            RADAR INDICATED.

0630 PM     TSTM WND DMG     COMMERCE                42.59N 83.49W 
09/11/2013                   OAKLAND            MI   911 CALL CENTER 

            TREES AND WIRES DOWN IN COMMERCE TOWNSHIP - TIME 
            ESTIMATED BY RADAR.

0644 PM     MARINE TSTM WIND 2 ENE MOUNT CLEMENS     42.61N 82.84W 
09/11/2013  M41.00 MPH       MACOMB             MI   ASOS            

            KMTC ASOS.

0653 PM     TSTM WND DMG     1 E NORTHVILLE          42.44N 83.47W 
09/11/2013                   WAYNE              MI   TRAINED SPOTTER 

            TREES UPROOTED AND NUMEROUS LARGE LIMBS DOWN.

0654 PM     TSTM WND DMG     2 SE ROYAL OAK          42.49N 83.13W 
09/11/2013                   OAKLAND            MI   TRAINED SPOTTER 

            BRANCH 10 INCHES IN DIAMETER AND 20 FEET LONG BLOCKING 
            ROAD. TIME ESTIMATED BY RADAR.

0655 PM     TSTM WND DMG     5 WNW LIVONIA           42.43N 83.47W 
09/11/2013                   WAYNE              MI   TRAINED SPOTTER 

            POWERLINES DOWN

0700 PM     TSTM WND DMG     FARMINGTON              42.46N 83.38W 
09/11/2013                   OAKLAND            MI   TRAINED SPOTTER 

            BILLBOARD REPORTED DOWN

0700 PM     TSTM WND DMG     1 N LIVONIA             42.41N 83.37W 
09/11/2013                   WAYNE              MI   TRAINED SPOTTER 

            TREES DOWN DAMAGING A CAR. TREES ALSO DOWN ON WIRES.

0709 PM     MARINE TSTM WIND 2 ENE MOUNT CLEMENS     42.61N 82.84W 
09/11/2013  M60.00 MPH       MACOMB             MI   ASOS            

            KMTC ASOS GUSTED ABOVE 39 MPH FROM 701 PM THROUGH 717 PM.


0709 PM     TSTM WND GST     2 ENE MOUNT CLEMENS     42.61N 82.84W 
09/11/2013  M60.00 MPH       MACOMB             MI   ASOS            

            KMTC OBSERVATION GUSTED THROUGH 713 PM.
  
0724 PM     TSTM WND DMG     1 NW GROSSE ILE         42.14N 83.16W 
09/11/2013                   WAYNE              MI   LAW ENFORCEMENT 

            TREE DOWN AT THE INTERSECTION OF LOWRIE AND MARQUETTE DR.
            RADAR ESTIMATED TIME.

0730 PM     TSTM WND DMG     ALGONAC                 42.62N 82.53W 
09/11/2013                   ST. CLAIR          MI   911 CALL CENTER 

            DISPATCH REPORTS TREES AND WIRES DOWN. BRANCHES DOWN ON 
            CAR. TIME ESTIMATED FROM RADAR.

0830 PM     HEAVY RAIN       WATERFORD               42.66N 83.39W 
09/11/2013  M1.50 INCH       OAKLAND            MI   TRAINED SPOTTER 

            3 HOUR TOTAL


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