Alert archive / Minnesota / Tornado Watches in 2012

Tornado Watch 465

July 4, 201215 counties in Minnesota; 6 counties in Wisconsin

The Storm Prediction Center issued this tornado watch at Jul 4, 2012, 8:59 PM CDT for 15 counties in Minnesota; 6 counties in Wisconsin. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jul 4, 2012, 8:59 PM CDT (01:59 UTC)
Expired: Jul 5, 2012, 1:51 AM CDT
In force: 5 hr
Issued by: the Storm Prediction Center
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 21 counties

Aitkin County, MN, Benton County, MN, Cass County, MN, Chisago County, MN, Crow Wing County, MN, Hubbard County, MN, Isanti County, MN, Kanabec County, MN, Mille Lacs County, MN, Morrison County, MN, Pine County, MN, Sherburne County, MN, Stearns County, MN, Todd County, MN, Wadena County, MN, Barron County, WI, Burnett County, WI, Polk County, WI, Rusk County, WI, Sawyer County, WI, Washburn County, WI

The radar

The Duluth radar (KDLH), 123 km from the middle of the area, began a volume at 02:01 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: 30%
One or more EF2 to EF5 tornadoes: 20%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 10%
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

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

Issued	Product	Office	Counties	Lasted
Jul 4, 9:02 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Crow Wing	43 min
Jul 4, 9:23 PM CDT	Tornado Warning	DLH	Cass	52 min
Jul 4, 9:44 PM CDT	Tornado Warning	MPX	Morrison, Todd	31 min
Jul 4, 9:53 PM CDT	Tornado Warning	DLH	Cass, Crow Wing	22 min
Jul 4, 9:54 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Crow Wing	51 min
Jul 4, 10:09 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Crow Wing	36 min
Jul 4, 10:14 PM CDT	Tornado Warning	DLH	Cass, Crow Wing	34 min
Jul 4, 10:15 PM CDT	Severe Thunderstorm Warning	MPX	Morrison	15 min
Jul 4, 10:28 PM CDT	Tornado Warning	DLH	Cass, Crow Wing	23 min
Jul 4, 10:45 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton	45 min
Jul 5, 12:04 AM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs	41 min
Jul 5, 12:12 AM CDT	Severe Thunderstorm Warning	DLH	Burnett, Douglas, Washburn	48 min
Jul 5, 12:34 AM CDT	Severe Thunderstorm Warning	MPX	Chisago, Isanti, Kanabec, Mille Lacs	41 min
Jul 5, 1:11 AM CDT	Severe Thunderstorm Warning	MPX	Chisago	16 min

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.0 hours before the alert went out and 141 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: 2542 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 1972 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 163 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 5.8

Open this sounding in Storm Lab

The text

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

278 
WWUS20 KWNS 050158
SEL5
SPC WW 050158
MNZ000-WIZ000-050800-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 465
NWS STORM PREDICTION CENTER NORMAN OK
900 PM CDT WED JUL 4 2012

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

       CENTRAL MINNESOTA
       NORTHWEST WISCONSIN

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 900 PM
UNTIL 300 AM CDT.

TORNADOES...HAIL TO 2 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 35 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 50 MILES WEST OF BRAINERD
MINNESOTA TO 175 MILES EAST SOUTHEAST OF BRAINERD MINNESOTA.  FOR
A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).

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 461...WW 464...

DISCUSSION...PER DISCUSSION IN SVR TSTMS WATCH # 464...CONDITIONS
APPEAR SOMEWHAT SUPPORT OF TORNADOES IN A NARROW WNW-ESE CORRIDOR
THROUGH CNTRL MN...ALONG AND JUST N OF STALLED OUTFLOW BOUNDARY FROM
EARLIER STORMS.  GREATEST RISK WOULD BE FROM ANY SUSTAINED STORMS
WITH STRONGLY DEVIANT /SEWD/ MOTION.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 29025.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 4, 7:31 PM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Becker, Beltrami, Carlton, Cass, Clearwater and 12 more	5 hr
Jul 4, 10:54 PM CDT	Mesoscale Discussion	SPC	Adams, Calumet, Columbia, Dodge, Fond du Lac, Green Lake and 13 more	96 min

Nearby

Tornado Watches in Minnesota, 2012 Tornado Watches in Wisconsin, 2012 Every tornado 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.