Alert archive / Michigan / Severe Thunderstorm Watches in 2012
Severe Thunderstorm Watch 522
The Storm Prediction Center issued this severe thunderstorm watch at Jul 25, 2012, 9:47 PM EDT for 15 counties in Michigan. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 25, 2012, 9:47 PM EDT (01:47 UTC)
- Expired
- Jul 26, 2012, 3:51 AM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
Counties Bay County, MI, Genesee County, MI, Huron County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Midland 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), 72 km from the middle of the area, began a volume at 01:49 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
- 20%
- One or more EF2 to EF5 tornadoes
- 5%
- Ten or more severe wind reports
- 80%
- One or more gusts of 65 knots or more
- 70%
- 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
- 95%
Warnings issued inside it
8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 25, 10:25 PM EDT | Severe Thunderstorm Warning | DTX | Bay, Midland | 40 min |
| Jul 25, 11:12 PM EDT | Severe Thunderstorm Warning | DTX | Huron, Sanilac, Tuscola | 93 min |
| Jul 25, 11:55 PM EDT | Severe Thunderstorm Warning | DTX | Bay, Midland, Saginaw | 95 min |
| Jul 26, 12:13 AM EDT | Severe Thunderstorm Warning | DTX | Sanilac, Tuscola | 62 min |
| Jul 26, 12:31 AM EDT | Severe Thunderstorm Warning | DTX | Huron, Tuscola | 54 min |
| Jul 26, 12:48 AM EDT | Severe Thunderstorm Warning | DTX | Lapeer, Saint Clair, Sanilac | 72 min |
| Jul 26, 1:00 AM EDT | Severe Thunderstorm Warning | DTX | Genesee, Lapeer, Shiawassee | 62 min |
| Jul 26, 1:37 AM EDT | Severe Thunderstorm Warning | DTX | Macomb, Oakland, Saint Clair | 47 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, 1.8 hours before the alert went out and 71 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1843 m above ground
- 0-6 km bulk shear
- 46 kt
- 0-1 km storm-relative helicity
- 226 m²/s²
- 0-3 km storm-relative helicity
- 373 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted, in the capitals the NWS used until 2016.
702
WWUS20 KWNS 260148
SEL2
SPC WW 260148
MIZ000-LHZ000-260900-
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 522
NWS STORM PREDICTION CENTER NORMAN OK
950 PM EDT WED JUL 25 2012
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
EASTERN LOWER MICHIGAN
LAKE HURON
EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 950 PM
UNTIL 500 AM 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 APPROXIMATELY ALONG AND 60
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHWEST OF
BAD AXE MICHIGAN TO 15 MILES SOUTHEAST OF ANN ARBOR MICHIGAN.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).
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...CONTINUE...WW 518...WW 519...WW 520...
DISCUSSION...COMPLEX MCS EVOLUTION IS ONGOING TONIGHT ACROSS
PORTIONS OF LAKE MI INTO NWRN LOWER MI. AHEAD OF THIS ACTIVITY...A
STRENGTHENING NOCTURNAL LOW-LEVEL WIND MAXIMUM WILL ENHANCE THE EWD
ADVECTION OF THERMODYNAMIC ENVIRONMENT SAMPLED BY 00Z GRB SOUNDING
INTO THE REGION. AT THE SAME TIME...DEEP WLY/WNWLY FLOW WILL
STRENGTHEN WITH SETUP BECOMING INCREASINGLY SUPPORTIVE OF A
WIDESPREAD DAMAGING WIND EVENT.
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 29040.
...MEADSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 25, 9:28 PM EDT | Mesoscale Discussion | SPC | Arenac, Bay, Clare, Clinton, Eaton, Genesee and 34 more | 92 min |
| Jul 26, 12:09 AM EDT | Mesoscale Discussion | SPC | Arenac, Bay, Clare, Clinton, Genesee, Gladwin and 26 more | 96 min |
| Jul 26, 2:40 AM EDT | Mesoscale Discussion | SPC | Allegan, Barry, Bay, Berrien, Branch, Calhoun and 41 more | 65 min |
Nearby
Severe Thunderstorm Watches in Michigan, 2012Every severe thunderstorm watch in 2012
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.