Alert archive / Michigan / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 41, NWS Gaylord, MI

July 29, 1987Chippewa County, Mackinac County, Michigan

NWS Gaylord, MI issued this severe thunderstorm warning at Jul 29, 1987, 7:00 PM EDT for Chippewa County, Mackinac County, Michigan. It was in force for 90 min.

The area

The counties it named.

The facts

Issued
Jul 29, 1987, 7:00 PM EDT (23:00 UTC)
Expired
Jul 29, 1987, 8:30 PM EDT
In force
90 min
Issued by
NWS Gaylord, MI
Area
Whole counties

Counties Chippewa County, MI, Mackinac County, MI

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Sault Ste Marie, MI (KSSM), launched 12:00Z, 11.0 hours before the alert went out and 49 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, Sault Ste Marie, MI at 12:00Z on 1987-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Sault Ste Marie, MI at 12:00Z on 1987-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1137 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
123 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 KSSM 292309
SVRSSM
MIC033-097-300030-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE SAULT STE MARIE MI
700 PM EDT WED JUL 29 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A
SEVERE THUNDERSTORM WARNING AND SPECIAL MARINE WARNING
EFFECTIVE UNTIL  830 PM EDT FOR PEOPLE IN THE FOLLOWING COUNTIES...

IN NORTHERN MICHIGAN
          ...CHIPPEWA AND MACKINAC

AND ADJOINING COASTAL WATERS OF LAKES MICHIGAN AND HURON...

AT 7PM EDT AN AREA OF THUNDERSTORMS ...SOME NEARING SEVERE LEVELS...
WAS OVER CHIPPEWA COUNTY FROM ABOUT 30 MILES NORTHEAST OF THE STRAITS
OF MACKINAC BRIDGE TO ABOUT 50 MILES NORTHWEST OF THE STRAITS OF
MACKINAC.  THESE STORMS WERE IN AN EAST TO WEST LINE ABOUT 20 MILES
WIDE...AND WERE MOVING TO THE SOUTHEAST AT ABOUT 25 MPH.
 
THUNDERSTORMS ARE EXPECTED TO PASS NEAR THE TOWNS OF TROUT
LAKE...RUDYARD...KINROSS...PICKFORD...CEDARVILLE AND
DETOUR BY 830 PM EDT.  THESE THUNDERSTORMS MAY CONTAIN     
DAMAGING HAIL...STRONG THUNDERSTORM WINDS AND DANGEROUS
LIGHTNING.

IF THREATENING WEATHER APPROACHES YOU SHOULD GO TO A SAFE
PLACE IMMEDIATELY...AND YOU SHOULD ASK THE NEAREST LAW
ENFORCEMENT AGENCY TO RELAY YOUR SEVERE WEATHER REPORTS TO
THE NATIONAL WEATHER SERVICE.

SMALL CRAFT ON THE NORTH SHORE OF LAKE MICHIGAN...FROM PORT
INLAND TO ST IGNACE...  ON THE NORTH SHORE OF LAKE HURON...ST
IGNACE TO DRUMMOND ISLAND...  ON THE LOWER ST MARYS RIVER
SYSTEM...AND NEAR+ THE STRAITS OF MACKINAC SHOULD SEEK SAFE
HARBOR IMMEDIATELY.

LHW

Nearby

Severe Thunderstorm Warnings in Michigan, 1987Every severe thunderstorm warning in 1987

Sources

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