Alert archive / Michigan / Tornado Watches in 2001

Tornado Watch 138

April 11, 200121 counties in Michigan

The Storm Prediction Center issued this tornado watch at Apr 11, 2001, 7:15 PM EDT for 21 counties in Michigan. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Apr 11, 2001, 7:15 PM EDT (23:15 UTC)
Expired: Apr 12, 2001, 12:00 AM EDT
In force: 5 hr
Issued by: the Storm Prediction Center

All 21 counties

Allegan County, MI, Barry County, MI, Calhoun County, MI, Clare County, MI, Clinton County, MI, Eaton County, MI, Gratiot County, MI, Ionia County, MI, Isabella County, MI, Kalamazoo County, MI, Kent County, MI, Lake County, MI, Mason County, MI, Mecosta County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Osceola County, MI, Ottawa County, MI, Van Buren County, MI

Warnings issued inside it

11 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Apr 11, 7:27 PM EDT	Severe Thunderstorm Warning	GRR	Muskegon, Ottawa	48 min
Apr 11, 7:35 PM EDT	Tornado Warning	GRR	Ottawa	40 min
Apr 11, 7:51 PM EDT	Tornado Warning	GRR	Muskegon	24 min
Apr 11, 7:53 PM EDT	Flash Flood Warning	GRR	Muskegon, Newaygo, Oceana, Osceola	112 min
Apr 11, 8:06 PM EDT	Tornado Warning	GRR	Kent	29 min
Apr 11, 8:36 PM EDT	Severe Thunderstorm Warning	GRR	Mecosta, Montcalm	39 min
Apr 11, 9:51 PM EDT	Flash Flood Warning	GRR	Muskegon	3 hr
Apr 11, 11:21 PM EDT	Severe Thunderstorm Warning	GRR	Muskegon, Ottawa	39 min
Apr 11, 11:36 PM EDT	Severe Thunderstorm Warning	GRR	Newaygo	24 min
Apr 11, 11:45 PM EDT	Tornado Warning	GRR	Newaygo	30 min
Apr 11, 11:58 PM EDT	Tornado Warning	GRR	Muskegon	17 min

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 11.3 hours before the alert went out and 173 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 849 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 250 m²/s²
0-3 km storm-relative helicity: 293 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 
WWUS9 KMKC 112306
SEL8  

SEL8  
MKC WW 112300
MIZ000-120400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 138
STORM PREDICTION CENTER NORMAN OK
700 PM EDT WED APR 11 2001

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   WESTERN LOWER MICHIGAN                           
   EASTERN LAKE MICHIGAN 

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 715 PM
UNTIL MIDNIGHT EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 60 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 50 STATUTE MILES EAST AND WEST
OF A LINE FROM 75 MILES NORTH NORTHEAST OF MUSKEGON MICHIGAN TO 10
MILES SOUTH SOUTHEAST OF KALAMAZOO MICHIGAN.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 135...WW 136...WW 137...

DISCUSSION...SLIGHTLY ELEVATED BAND OF THUNDERSTORMS FORMING ATTM
IN DIFFLUENT CORRIDOR OF WARM CONVEYOR BELT EXPECTED TO INTENSIFY 
THIS EVENING AND BECOME SURFACE-BASED AS SRN MI WARM FRONT
CONTINUES NWD.  VERY STRONG /70+ KT/ DEEP LAYER SHEAR WILL REMAIN
SUPPORTIVE OF SUPERCELLS...WITH LOW LEVEL HELICITY ENHANCED INVOF
WARM FRONT/STORM OUTFLOW BOUNDARIES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 50 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. 
MEAN STORM MOTION VECTOR 24035.


...CORFIDI

;441,0843 420,0843 420,0862 441,0863;

Nearby

Tornado Watches in Michigan, 2001 Every tornado watch in 2001

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.