Alert archive / Michigan / Tornado Watches in 2002

Tornado Watch 541

July 27, 200210 counties in Michigan; 4 counties in Ohio

The Storm Prediction Center issued this tornado watch at Jul 27, 2002, 10:30 PM EDT for 10 counties in Michigan; 4 counties in Ohio. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jul 27, 2002, 10:30 PM EDT (02:30 UTC)
Expired: Jul 28, 2002, 4:00 AM EDT
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Barry County, MI, Branch County, MI, Calhoun County, MI, Eaton County, MI, Hillsdale County, MI, Jackson County, MI, Lenawee County, MI, Monroe County, MI, Washtenaw County, MI, Wayne County, MI, Fulton County, OH, Lucas County, OH, Sandusky County, OH, Wood County, OH

The radar

The Detroit radar (KDTX), 104 km from the middle of the area, began a volume at 02:30 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

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

Issued	Product	Office	Counties	Lasted
Jul 28, 12:27 AM EDT	Severe Thunderstorm Warning	DTX	Lenawee	63 min
Jul 28, 12:37 AM EDT	Severe Thunderstorm Warning	DTX	Washtenaw	38 min

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 2.5 hours before the alert went out and 108 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: 269 J/kg
Mixed-layer CIN: -84 J/kg
Mixed-layer LCL: 1134 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 78 m²/s²
0-3 km storm-relative helicity: 217 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 2.9

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 280227
SEL1  
SPC WW 280230
MIZ000-OHZ000-LEZ000-280800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 541
STORM PREDICTION CENTER NORMAN OK
1030 PM EDT SAT JUL 27 2002

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

   SOUTHERN LOWER MICHIGAN                           
   NORTHWEST OHIO                               
   LAKE ERIE                          

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 1030 PM UNTIL
400 AM EDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 35 STATUTE MILES NORTH AND
SOUTH OF A LINE FROM 50 MILES WEST OF JACKSON MICHIGAN TO 35 MILES
SOUTH SOUTHEAST OF DETROIT 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 539...WW 540...

DISCUSSION...SEVERE THUNDERSTORMS HAVE DEVELOPED ALONG WARM FRONT
SRN MI.  WITH VERY UNSTABLE AIRMASS AND FAVORABLE SHEAR PROFILES 
SUPERCELLS LIKELY.  SUPERCELL CURRENTLY ALONG WARM FRONT N OF BTL
WILL CONTINUE TO BE A THREAT FOR TORNADOES AS IT TRACKS ESE.


AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 70 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 600. 
MEAN STORM MOTION VECTOR 28025.


...HALES

424,0852 421,0830 411,0830 414,0852

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 28, 2:50 PM EDT	Tornado Watch	SPC	Ashtabula, Geauga, Lake, Mahoning, Portage, Trumbull	5 hr

Nearby

Tornado Watches in Michigan, 2002 Tornado Watches in Ohio, 2002 Every tornado watch in 2002

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.