Alert archive / Michigan / Tornado Warnings in 1991

Tornado Warning 4, NWS Grand Rapids, MI

July 7, 1991Calhoun County, Michigan

NWS Grand Rapids, MI issued this tornado warning at Jul 7, 1991, 8:13 PM EDT for Calhoun County, Michigan. It was in force for 17 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
Jul 7, 1991, 8:13 PM EDT (00:13 UTC)
Expired
Jul 7, 1991, 8:30 PM EDT
In force
17 min
Issued by
NWS Grand Rapids, MI
Area
Whole counties

County Calhoun County, MI

What was reported inside it

TimeReportWhereRemark
Jul 7, 8:15 PM EDTThunderstorm Wind 0Calhoun, 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 00:00Z, 0.2 hours before the alert went out and 140 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 00:00Z on 1991-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1102 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 00:00Z on 1991-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.193958Sfc1 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
1102 J/kg
Mixed-layer CIN
-12 J/kg
Mixed-layer LCL
1632 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KLAN 080015
TORLAN
MIC025-080030-
 
BULLETIN - EBS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE LANSING MI
813 PM EDT SUN JUL 7 1991
 
THE NATIONAL WEATHER SERVICE IN LANSING HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  830 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION...
 
IN SOUTH CENTRAL MICHIGAN
 
   ...EASTERN CALHOUN COUNTY
 
AT 750 PM EDT A POSSIBLE TORNADO WAS SIGHTED OVER THE CITY OF MARSHALL
IN CALHOUN COUNTY. THE STORM WAS MOVING TO THE EAST AT 45 MPH AND WILL
BE OUT OF CALHOUN COUNTY BY 830 PM EDT.
 
 
IF YOU ARE IN THE PATH OF A TORNADO...THE SAFEST PLACE IS A
BASEMENT.  GET UNDER A WORKBENCH OR PIECE OF STURDY FURNITURE.
IF NO BASEMENT IS AVAILABLE...SEEK SHELTER /IN AN INTERIOR ROOM
SUCH AS A CLOSET ON THE LOWEST FLOOR.  USE BLANKETS...PILLOWS...
OR CUSHIONS TO COVER YOUR BODY.  AVOID WINDOWS.

What forecasters said that day

The local office's own words before this tornado 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, Jul 7, 5:49 PM EDT, 2 hours 24 minutes before
MIZ013-004-016-015-003-010-009-002-072245-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
548 PM EDT THU JUL 4 1991

...TORNADO WATCH IN EFFECT UNTIL 1100 PM EDT...
...STRONG THUNDERSTORMS APPROACHING THE EAST SHORE OF LAKE MICHIGAN...

AT 543 PM EDT...WEATHER RADAR SHOWED A LINE OF STRONG THUNDERSTORMS
APPROACHING THE EAST SHORE OF LAKE MICHIGAN. THE LINE WAS JUST OFFSHORE
GRAND HAVEN...TO 15 MILES WEST OF ST. JOSEPH. THE LINE WAS MOVING TO THE
EAST AT 50 MPH AND WILL REACH THE CITIES OF COOPERSVILLE AND PAW PAW
BY 615 PM EDT. THESE STORMS HAVE A HISTORY OF PRODUCING VERY STRONG
WINDS...HAIL...AND TORNADOES.

PERSONS IN SOUTHWEST LOWER MICHIGAN SHOULD BE ON THE LOOKOUT FOR
POSSIBLE SEVERE WEATHER. IF SEVERE WEATHER IS SIGHTED IN YOUR AREA...
TAKE COVER IMMEDIATELY. AFTER THE WEATHER HAS PASSED...NOTIFY YOUR
NEAREST LAW ENFORCEMENT AGENCY.
MJK
Special weather statement, Jul 7, 6:26 PM EDT, 1 hour 47 minutes before
MIZ011-012-018-020-022-023-025-040-041-080100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LANSING MI
625 PM EDT SUN JUL 7 1991

...TORNADO WATCH IN EFFECT FOR SOUTH CENTRAL LOWER MICHIGAN UNTIL
1100 PM EDT...

AT 600 PM EDT...WEATHER RADAR SHOWED STRONG THUNDERSTORMS EXTENDING
ACROSS MUCH OF CENTRAL AND SOUTHERN LAKE MICHIGAN...JUST REACHING THE
SHORE NEAR MUSKEGON. THE LINE OF STORMS WAS MOVING TO THE EAST AT 45 TO
50 MPH.

AROUND SOUTH CENTRAL LOWER MICHIGAN...SKIES WERE MOSTLY SUNNY WITH
TEMPERATURES IN THE UPPER 80S TO NEAR 90. THE WIND WAS FROM THE SOUTH-
WEST AT 5 TO 15 MPH.

SKIES WILL BECOME MOSTLY CLOUDY EARLY THIS EVENING ACROSS SOUTH CENTRAL
LOWER MICHIGAN. THE FAST MOVING THUNDERSTORMS ALONG THE LAKESHORE WILL
MOVE THROUGH THE AREA BETWEEN 730 AND 830 PM. TEMPERATURES WILL REMAIN
IN THE UPPER 80S EARLY...AND THEN FALL INTO THE MID 70S AFTER THE STORMS
MOVE THROUGH. WINDS WILL BE VARIABLE AT 5 TO 15 MPH AND THEN BECOME
WEST.

SOME OF THESE THUNDERSTORMS MAY BE SEVERE WITH STRONG WINDS... LARGE
HAIL... AND HEAVY RAIN. TORNADOES ARE ALSO POSSIBLE WITH THESE STORMS
IN SOUTH CENTRAL LOWER MICHIGAN. STAY TUNED TO NATIONAL WEATHER SERVICE
WEATHER RADIO FOR TH]E LATEST STATEMENTS AND UPDATES ON THIS DANGEROUS
WEATHER SITUATION.

SHEETS
Special weather statement, Jul 7, 7:01 PM EDT, 1 hour 12 minutes before
MIZ011-012-018-020-022-023-025-040-041-080100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LANSING MI
800 PM EDT SUN JUL 7 1991

...TORNADO WATCH IN EFFECT FOR SOUTH CENTRAL LOWER MICHIGAN UNTIL
1100 PM EDT...
...STRONG THUNDERSTORMS APPROACHING SOUTH CENTRAL LOWER MICHIGAN...

AT 700 PM EDT WEATHER RADAR INDICATED STRONG THUNDERSTORMS WERE
BEGINNING TO APPROACH SOUTH CENTRAL LOWER MICHIGAN. A LINE OF STORMS
EXTENDED FROM NEAR GRAND RAPIDS SOUTHWEST TO GRAND HAVEN...WITH
ANOTHER AREA IN BERRY COUNTY. THESE STORMS ARE MOVING TO THE EAST
BETWEEN 45 AND 50 MPH WITH THE LEADING STORM ENTERING EATON COUNTY
BY 720 PM EDT.

PERSONS IN THE PATH OF THESE STORMS SHOULD BE ON THE LOOKOUT FOR
STRONG GUSTY WINDS...POSSIBLE TORNADOES...FREQUENT DEADLY LIGHTNING
AND HEAVY RAINS.
.
STAY TUNED TO NATIONAL WEATHER SERVICE RADIO FOR THE LATEST STATEMENTS
AND UPDATES ON THE POTENTIALLY DANGEROUS WEATHER SITUATION.

P.LEWIS
Special weather statement, Jul 7, 7:05 PM EDT, 1 hour 8 minutes before
MIZ011-012-018-020-022-023-025-040-041-080100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LANSING MI
700 PM EDT SUN JUL 7 1991

...TORNADO WATCH IN EFFECT FOR SOUTH CENTRAL LOWER MICHIGAN UNTIL
1100 PM EDT...
...STRONG THUNDERSTORMS APPROACHING SOUTH CENTRAL LOWER MICHIGAN...

AT 700 PM EDT WEATHER RADAR INDICATED STRONG THUNDERSTORMS WERE
BEGINNING TO APPROACH SOUTH CENTRAL LOWER MICHIGAN. A LINE OF STORMS
EXTENDED FROM NEAR GRAND RAPIDS SOUTHWEST TO GRAND HAVEN...WITH
ANOTHER AREA IN BERRY COUNTY. THESE STORMS ARE MOVING TO THE EAST
BETWEEN 45 AND 50 MPH WITH THE LEADING STORM ENTERING EATON COUNTY
BY 720 PM EDT.

PERSONS IN THE PATH OF THESE STORMS SHOULD BE ON THE LOOKOUT FOR
STRONG GUSTY WINDS...POSSIBLE TORNADOES...FREQUENT DEADLY LIGHTNING
AND HEAVY RAINS.
.
STAY TUNED TO NATIONAL WEATHER SERVICE RADIO FOR THE LATEST STATEMENTS
AND UPDATES ON THE POTENTIALLY DANGEROUS WEATHER SITUATION.

P.LEWIS

...CORRECTION TO TIME IN HEADER...

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 8:15 PM EDTSevere Thunderstorm WarningGRRJackson60 min
Jul 7, 8:21 PM EDTSevere Thunderstorm WarningGRRHillsdale69 min

Nearby

Tornado Warnings in Michigan, 1991Every tornado warning in 1991Tornadoes 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.