Alert archive / Michigan / Tornado Watches in 2001

Tornado Watch 139

April 12, 200132 counties in Michigan

The Storm Prediction Center issued this tornado watch at Apr 12, 2001, 12:00 AM EDT for 32 counties in Michigan. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 12, 2001, 12:00 AM EDT (04:00 UTC)
Expired
Apr 12, 2001, 5:00 AM EDT
In force
5 hr
Issued by
the Storm Prediction Center
All 32 counties

Allegan County, MI, Barry County, MI, Bay County, MI, Calhoun County, MI, Clare County, MI, Clinton County, MI, Crawford County, MI, Eaton County, MI, Gladwin County, MI, Grand Traverse County, MI, Gratiot County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Jackson County, MI, Kalamazoo County, MI, Kalkaska County, MI, Kent County, MI, Lake County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montcalm County, MI, Newaygo County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Roscommon County, MI, Saginaw County, MI, Shiawassee County, MI, Van Buren County, MI, Wexford County, MI

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 12, 12:09 AM EDTSevere Thunderstorm WarningGRRKent36 min
Apr 12, 12:10 AM EDTFlash Flood WarningAPXCrawford, Montmorency6 hr
Apr 12, 12:14 AM EDTSevere Thunderstorm WarningGRRMecosta, Montcalm31 min
Apr 12, 12:19 AM EDTTornado WarningGRRNewaygo26 min
Apr 12, 12:25 AM EDTSevere Thunderstorm WarningGRROsceola35 min
Apr 12, 12:29 AM EDTTornado WarningGRRMecosta31 min
Apr 12, 12:42 AM EDTSevere Thunderstorm WarningGRRClare, Isabella48 min
Apr 12, 12:45 AM EDTSevere Thunderstorm WarningAPXMissaukee45 min
Apr 12, 12:57 AM EDTTornado WarningGRRClare, Osceola33 min
Apr 12, 1:13 AM EDTSevere Thunderstorm WarningAPXRoscommon47 min

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 4.0 hours before the alert went out and 160 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 2001-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 156 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 2001-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 196 square meters per square second.19395878Sfc1 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
156 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
557 m above ground
0-6 km bulk shear
66 kt
0-1 km storm-relative helicity
196 m²/s²
0-3 km storm-relative helicity
233 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.6

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 120400
SEL9  

SEL9  
MKC WW 120355
MIZ000-120900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 139
STORM PREDICTION CENTER NORMAN OK
1155 PM EDT WED APR 11 2001

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

     LOWER MICHIGAN                           

EFFECTIVE THIS THURSDAY MORNING FROM MIDNIGHT EDT UNTIL 500 AM EDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO
70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 55 STATUTE MILES EAST AND WEST
OF A LINE FROM 15 MILES SOUTHEAST OF KALAMAZOO MICHIGAN TO 35 MILES
NORTH OF HOUGHTON LAKE 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...THIS TORNADO WATCH REPLACES TORNADO WATCH
NUMBER 138.  WATCH NUMBER 138 WILL NOT BE IN EFFECT AFTER MIDNIGHT
EDT.

DISCUSSION...THREAT FOR ISOLATED TORNADOES EXPECTED TO PERSIST OVER
WW REGION AS ZONE OF VERY STRONG /AOA 75 KTS/ DEEP LAYER SHEAR 
OVERSPREADS REGION FROM THE SW.  WHILE SHEAR IS LARGELY
UNIDIRECTIONAL...STRENGTH SUGGESTS POTENTIAL FOR EMBEDDED
SUPERCELLS WITH LEWP CREST TORNADOES. 

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS `WITH HAIL
SURFACE AND ALOFT TO 1 INCH...EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 22045.

...CORFIDI

;445,0833 420,0841 420,0862 445,0854;

Nearby

Tornado Watches in Michigan, 2001Every 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.