Alert archive / Michigan / Tornado Watches in 2008

Tornado Watch 256

May 2, 200821 counties in Indiana; 34 counties in Michigan

The Storm Prediction Center issued this tornado watch at May 2, 2008, 9:13 PM EDT for 21 counties in Indiana; 34 counties in Michigan. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
May 2, 2008, 9:13 PM EDT (01:13 UTC)
Expired
May 3, 2008, 12:13 AM EDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 55 counties

Adams County, IN, Allen County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Huntington County, IN, Kosciusko County, IN, LaGrange County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Noble County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, White County, IN, Whitley County, IN, Allegan County, MI, Arenac County, MI, Barry County, MI, Bay County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clare County, MI, Clinton County, MI, Eaton County, MI, Gladwin County, MI, Gratiot County, MI, Hillsdale County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Jackson County, MI, Kalamazoo County, MI, Kent County, MI, Lake County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Osceola County, MI, Ottawa County, MI, Saginaw County, MI, Saint Joseph County, MI, Shiawassee County, MI, Van Buren County, MI

The radar

The Grand Rapids radar (KGRR), 15 km from the middle of the area, began a volume at 01:17 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 2, 9:19 PM EDTSevere Thunderstorm WarningIWXLaPorte, Marshall, Pulaski, Saint Joseph, Starke56 min
May 2, 9:56 PM EDTSevere Thunderstorm WarningGRRAllegan, Muskegon, Newaygo, Oceana, Ottawa, Van Buren49 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 1.2 hours before the alert went out and 178 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 2008-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 38 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 2008-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 348 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
38 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
562 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
348 m²/s²
0-3 km storm-relative helicity
425 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 030113
SEL6  
SPC WW 030113
INZ000-MIZ000-LMZ000-030600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 256
NWS STORM PREDICTION CENTER NORMAN OK
915 PM EDT FRI MAY 2 2008

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

       MUCH OF NORTHERN INDIANA
       LARGE PART OF LOWER MICHIGAN
       LAKE MICHIGAN

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 915 PM
UNTIL 200 AM EDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHEAST OF ROBEN
HOOD MICHIGAN TO 45 MILES WEST SOUTHWEST OF FORT WAYNE INDIANA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU6).

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 253...WW 254...WW 255...

DISCUSSION...THUNDERSTORMS ARE INCREASING ALONG COLD FRONT EXTENDING
SWD THRU SRN LM INTO NWRN IND.  WITH STRONG SHEAR IN PLACE AND
ADEQUATE INSTABILITY...POTENTIAL FOR EMBEDDED LOW TOPPED SUPERCELLS
WITHIN LINE OF STORMS ALONG FRONT.  TORNADOS ALONG WITH DAMAGING
WINDS ARE POSSIBLE WITH THE SUPERCELLS THAT DEVELOP.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
400. MEAN STORM MOTION VECTOR 23035.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 8:50 PM EDTMesoscale DiscussionSPCBenton, Boone, Carroll, Cass, Clinton, Elkhart and 29 more85 min

Nearby

Tornado Watches in Michigan, 2008Tornado Watches in Indiana, 2008Every tornado watch in 2008

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.