Alert archive / Michigan / Tornado Watches in 2001

Tornado Watch 266

May 21, 200123 counties in Michigan

The Storm Prediction Center issued this tornado watch at May 21, 2001, 3:00 PM EDT for 23 counties in Michigan. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: May 21, 2001, 3:00 PM EDT (19:00 UTC)
Expired: May 21, 2001, 7:00 PM EDT
In force: 4 hr
Issued by: the Storm Prediction Center

All 23 counties

Barry County, MI, Bay County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Kent County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Newaygo County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI

The radar

The Grand Rapids radar (KGRR), 93 km from the middle of the area, began a volume at 19:04 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
May 21, 3:02 PM EDT	Tornado Warning	GRR	Clinton	28 min
May 21, 3:21 PM EDT	Tornado Warning	GRR	Eaton, Ionia	39 min
May 21, 3:30 PM EDT	Tornado Warning	GRR	Kent	45 min
May 21, 3:37 PM EDT	Tornado Warning	GRR	Gratiot	23 min
May 21, 3:57 PM EDT	Tornado Warning	GRR	Gratiot	18 min
May 21, 4:14 PM EDT	Tornado Warning	GRR	Gratiot, Isabella	31 min
May 21, 4:45 PM EDT	Tornado Warning	GRR	Isabella	30 min
May 21, 4:52 PM EDT	Tornado Warning	DTX	Genesee, Lapeer	38 min
May 21, 4:57 PM EDT	Tornado Warning	GRR	Gratiot	18 min
May 21, 5:15 PM EDT	Tornado Warning	GRR	Clare, Isabella	30 min

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 7.0 hours before the alert went out and 107 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: 293 J/kg
Mixed-layer CIN: -53 J/kg
Mixed-layer LCL: 630 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 134 m²/s²
0-3 km storm-relative helicity: 164 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.9

Open this sounding in Storm Lab

The text

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

000 
WWUS9 KMKC 211848
SEL6  

SEL6  
MKC WW 211841
MIZ000-212300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 266
STORM PREDICTION CENTER NORMAN OK
141 PM CDT MON MAY 21 2001

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

   CENTRAL LOWER MICHIGAN                           

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 200 PM UNTIL 600
PM CDT.

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 40 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 25 MILES NORTHWEST OF GRAND RAPIDS MICHIGAN TO
65 MILES EAST NORTHEAST OF FLINT 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 264...WW 265...

DISCUSSION...CLUSTER OF LOW-TOPPED SUPERCELL STORMS CONTINUES TO
AFFECT PARTS OF CENTRAL LOWER MI.  THESE STORMS ARE IN VICINITY OF
NORTHWARD MOVING WARM FRONT...WHERE ENHANCED LOW LEVEL SHEAR
PROFILES ARE AIDING FORMATION OF BRIEF TORNADOES.  RELATIVELY WEAK
INSTABILITY SHOULD LIMIT AREAL/TEMPORAL COVERAGE OF SEVERE THREAT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND A`LOFT TO 1 INCH...EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. 
MEAN STORM MOTION VECTOR 18030.

...HART

;434,0855 435,0823 424,0823 423,0855;

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; radar from the NEXRAD Level II archive.