Alert archive / Michigan / Severe Thunderstorm Watches in 2004
Severe Thunderstorm Watch 421
The Storm Prediction Center issued this severe thunderstorm watch at Jun 9, 2004, 6:05 PM EDT for 29 counties in Michigan. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 9, 2004, 6:05 PM EDT (22:05 UTC)
- Expired
- Jun 10, 2004, 12:00 AM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 29 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, Lake County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oakland County, MI, Oceana County, MI, Osceola County, MI, Ottawa 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), 69 km from the middle of the area, began a volume at 22:07 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 |
|---|---|---|---|---|
| Jun 9, 6:24 PM EDT | Severe Thunderstorm Warning | DTX | Oakland | 81 min |
| Jun 9, 9:35 PM EDT | Severe Thunderstorm Warning | GRR | Clinton | 40 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 12:00Z, 10.1 hours before the alert went out and 145 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.
- Mixed-layer CAPE
- 1547 J/kg
- Mixed-layer CIN
- -41 J/kg
- Mixed-layer LCL
- 972 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -26 m²/s²
- 0-3 km storm-relative helicity
- 34 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 092204
SEL1
SPC WW 092205
MIZ000-LMZ000-LHZ000-100400-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 421
NWS STORM PREDICTION CENTER NORMAN OK
605 PM EDT WED JUN 9 2004
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
CENTRAL AND SOUTHERN LOWER MICHIGAN
LAKE MICHIGAN
LAKE HURON
EFFECTIVE THIS WEDNESDAY NIGHT FROM 605 PM UNTIL MIDNIGHT EDT.
HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 55 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 20 MILES WEST NORTHWEST OF MUSKEGON
MICHIGAN TO 35 MILES NORTH NORTHEAST OF MOUNT CLEMENS MICHIGAN.
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.
OTHER WATCH INFORMATION...THIS SEVERE THUNDERSTORM WATCH REPLACES
SEVERE THUNDERSTORM WATCH NUMBER 414. WATCH NUMBER 414 WILL NOT BE
IN EFFECT AFTER 605 PM EDT. CONTINUE...WW 417...WW 418...WW
419...WW 420...
DISCUSSION...THUNDERSTORMS...INCLUDING POSSIBLE ROTATING
STORMS...EXPECTED TO CONTINUE DEVELOPING IN ZONE OF STRONG
SURFACE-BASED INSTABILITY /MLCAPE TO 2000 J/KG/ ALONG AND S OF W/E
ORIENTED COLD FRONT.
AVIATION...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 500. MEAN STORM
MOTION VECTOR 26030.
...CORFIDI
440,0863 435,0823 421,0823 422,0863SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 9, 11:21 AM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Berrien, Branch, Calhoun, Cass and 27 more | 114 min |
| Jun 9, 12:35 PM EDT | Severe Thunderstorm Watch | SPC | Branch, Calhoun, Clinton, Eaton, Genesee, Gratiot and 20 more | 5 hr |
| Jun 9, 2:51 PM EDT | Mesoscale Discussion | SPC | Barry, Branch, Calhoun, Clinton, Eaton, Genesee and 22 more | 84 min |
| Jun 9, 5:27 PM EDT | Mesoscale Discussion | SPC | Bay, Branch, Calhoun, Clinton, Eaton, Genesee and 22 more | 63 min |
Nearby
Severe Thunderstorm Watches in Michigan, 2004Every severe thunderstorm watch in 2004
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.