Alert archive / Michigan / Tornado Watches in 2007
Tornado Watch 727
The Storm Prediction Center issued this tornado watch at Oct 18, 2007, 11:52 PM EDT for 21 counties in Michigan. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 18, 2007, 11:52 PM EDT (03:52 UTC)
- Expired
- Oct 19, 2007, 3:55 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 21 counties
Bay County, MI, Calhoun County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Huron County, MI, Ingham County, MI, Jackson County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI
The radar
The Detroit radar (KDTX), 36 km from the middle of the area, began a volume at 03:55 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
- 30%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
7 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 18, 11:52 PM EDT | Tornado Warning | GRR | Ingham, Jackson | 23 min |
| Oct 19, 12:02 AM EDT | Severe Thunderstorm Warning | DTX | Livingston, Shiawassee | 58 min |
| Oct 19, 12:07 AM EDT | Severe Thunderstorm Warning | GRR | Ingham | 38 min |
| Oct 19, 12:20 AM EDT | Tornado Warning | GRR | Ingham | 25 min |
| Oct 19, 12:32 AM EDT | Severe Thunderstorm Warning | DTX | Genesee | 73 min |
| Oct 19, 1:00 AM EDT | Severe Thunderstorm Warning | DTX | Lapeer, Tuscola | 65 min |
| Oct 19, 1:15 AM EDT | Tornado Warning | DTX | Tuscola | 38 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, 3.9 hours before the alert went out and 34 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
- 504 J/kg
- Mixed-layer CIN
- -26 J/kg
- Mixed-layer LCL
- 1038 m above ground
- 0-6 km bulk shear
- 77 kt
- 0-1 km storm-relative helicity
- 354 m²/s²
- 0-3 km storm-relative helicity
- 339 m²/s²
- Significant tornado parameter
- 1.2
- Supercell composite
- 4.4
The text
As transmitted, in the capitals the NWS used until 2016.
000
WWUS20 KWNS 190346
SEL7
SPC WW 190346
MIZ000-LEZ000-LHZ000-191000-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 727
NWS STORM PREDICTION CENTER NORMAN OK
1150 PM EDT THU OCT 18 2007
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
EASTERN LOWER MICHIGAN
LAKE ERIE
LAKE HURON
EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1150 PM
UNTIL 600 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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES EAST NORTHEAST OF BAD
AXE MICHIGAN TO 40 MILES SOUTH SOUTHEAST OF JACKSON MICHIGAN.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU7).
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 722...WW 724...WW
725...WW 726...
DISCUSSION...SUPERCELL STORMS CONTINUE TO AFFECT PARTS OF EASTERN
LOWER MI. THESE STORMS WILL PERSIST FOR SEVERAL MORE HOURS...IN
REGION OF VERY FAVORABLE VERTICAL SHEAR AND SUFFICIENT INSTABILITY.
DAMAGING WINDS AND ISOLATED TORNADOES WILL REMAIN A RISK THROUGH THE
EARLY MORNING HOURS.
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
500. MEAN STORM MOTION VECTOR 24035.
...HARTSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 18, 10:57 PM EDT | Mesoscale Discussion | SPC | Arenac, Barry, Bay, Branch, Calhoun, Cass and 29 more | 93 min |
Nearby
Tornado Watches in Michigan, 2007Every tornado watch in 2007
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.