Alert archive / Michigan / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 21, NWS Detroit, MI

May 13, 1991Lenawee County, Monroe County, Washtenaw County, Michigan

NWS Detroit, MI issued this severe thunderstorm warning at May 13, 1991, 4:20 PM EDT for Lenawee County, Monroe County, Washtenaw County, Michigan. It was in force for 55 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
May 13, 1991, 4:20 PM EDT (20:20 UTC)
Expired
May 13, 1991, 5:15 PM EDT
In force
55 min
Issued by
NWS Detroit, MI
Area
Whole counties

Counties Lenawee County, MI, Monroe County, MI, Washtenaw County, MI

What was reported inside it

TimeReportWhereRemark
May 13, 4:30 PM EDTThunderstorm Wind 52Washtenaw, MI

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in. Storm Data before 1996 records only tornadoes, thunderstorm wind and hail.

The nearest sounding before it

Detroit, MI (KFNT), launched 12:00Z, 8.3 hours before the alert went out and 83 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Detroit, MI at 12:00Z on 1991-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 282 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 12:00Z on 1991-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
282 J/kg
Mixed-layer CIN
-126 J/kg
Mixed-layer LCL
1230 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
16 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KDTW 132020
SVRDTW
MIC161-091-115-132115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING 
NATIONAL WEATHER SERVICE DETROIT MI
420 PM EDT MON MAY 13 1991

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM 
WARNING EFFECTIVE UNTIL 515 PM EDT FOR PEOPLE IN THE FOLLOWING 
COUNTIES

   IN THE SOUTHEAST PART OF LOWER MICHIGAN
      WASHTENAW...LENAWEE...MONROE

AT 415 PM EST...RADAR INDICATED SEVERE THUNDERSTORMS...55 MILES
WEST TO 40 MILES SOUTHWEST OF DOWNTOWN DETROIT.  LENAWEE COUNTY
SHERIFFS DEPARTMENT REPORTED WINDS IN EXCESS OF 60 MILES AN HOUR
NEAR ADRIAN.  MOVEMENT WAS EAST AT 25 MILES AN HOUR.

PERSONS IN THE CITIES OF MANCHESTER...ADRIAN AND DUNDEE SHOULD
TAKE COVER NOW.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 55
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLO"OD ROADWAYS QUICKLY...
AVOID DRIVING INTO AREAS WHERE WATER COVERS THE ROAD.

 ZALESKI

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, May 13, 11:28 AM EDT, 4 hours 52 minutes before
MIZALL-132200-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANN ARBOR MI
1130 AM EDT MON MAY 13 1991

...SEVERE WEATHER POTENTIAL STATEMENT FOR MICHIGAN...

AT 1100 AM...SCATTERED THUNDERSTORMS WERE NEAR ALPENA AND OVER
NORTHERN LAKES MICHIGAN AND HURON THROUGH THE STRAITS AREA. THESE
STORMS WERE MOVING SOUTHEAST.

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON OVER
UPPER MICHIGAN. THERE IS A CHANCE THAT SOME OF THESE STORMS COULD
PRODUCE SEVERE WEATHER THIS AFTERNOON AND EVENING. WIND GUSTS OVER
50 MPH ARE POSSIBLE AS WELL AS HAIL TO ONE INCH IN DIAMETER.

SCATTERED THUNDERSTORMS ARE ALSO EXPECTED IN LOWER MICHIGAN LATE
THIS AFTERNOON...BUT THEY ARE NOT EXPECTED TO BE SEVERE. THERE IS A
CHANCE THAT SOME STORMS IN NORTH LOWER MICHIGAN COULD APPROACH
SEVERE LEVELS TONIGHT. IN ADDITION...THUNDERSTORMS THAT OCCUR IN THE
MOIST AIR OVER MICHIGAN THIS AFTERNOON AND TONIGHT MAY PRODUCE SOME
LOCALLY HEAVY DOWNPOURS.

IF FURTHER DEVELOPMENTS CONFIRM THIS SEVERE WEATHER OUTLOOK...
WATCHES...WARNINGS...AND STATEMENTS WILL BE ISSUED AS NECESSARY.

WH
Special weather statement, May 13, 3:49 PM EDT, 31 minutes before
MIZ019>035-131945-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DETROIT MI
345 PM EDT WED MAY 13 1991

...INTENSE THUNDERSTORMS HAVE RAPIDLY DEVELOPED OVER SOUTHEAST LOWER
   MICHIGAN...

AT 330 PM...AN AREA OF SCATTERED SHOWERS AND THUNDERSTORMS...120
MILES WIDE...PRODUCING VERY HEAVY RAIN...WAS OVER SOUTHWEST SOUTH
CENTRAL AND SOUTHEAST LOWER MICHIGAN...AND PARTS OF EXTREME NORTHWEST
OHIO.

THE HEAVIEST SHOWERS AND THUNDERSTORMS EXTENDED FROM 20 MILES
NORTHEAST OF JACKSON MICHIGAN SOUTHEAST TO TOLEDO OHIO.

MOVEMET WAS TO THE EAST NORTHEAST AT 25 MILES AN HOUR.

RPN

The office that day

Everything else NWS Detroit, MI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 13, 5:08 PM EDTSevere Thunderstorm WarningDTXMonroe, Wayne67 min

Nearby

Severe Thunderstorm Warnings in Michigan, 1991Every severe thunderstorm warning in 1991

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.