Alert archive / Minnesota / Tornado Watches in 2011

Tornado Watch 496

June 17, 201114 counties in Minnesota

The Storm Prediction Center issued this tornado watch at Jun 17, 2011, 7:22 PM CDT for 14 counties in Minnesota. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Jun 17, 2011, 7:22 PM CDT (00:22 UTC)
Expired
Jun 18, 2011, 2:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Chippewa County, MN, Douglas County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, McLeod County, MN, Meeker County, MN, Pope County, MN, Redwood County, MN, Renville County, MN, Sibley County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Yellow Medicine County, MN

The radar

The Minneapolis radar (KMPX), 170 km from the middle of the area, began a volume at 00:23 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
20%
One or more gusts of 65 knots or more
5%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
50%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jun 17, 7:57 PM CDTSevere Thunderstorm WarningMPXKandiyohi33 min
Jun 17, 8:18 PM CDTSevere Thunderstorm WarningMPXKandiyohi27 min
Jun 17, 9:33 PM CDTSevere Thunderstorm WarningMPXChippewa, Lac qui Parle, Swift57 min
Jun 17, 9:55 PM CDTSevere Thunderstorm WarningMPXChippewa, Lac qui Parle, Yellow Medicine35 min
Jun 17, 10:09 PM CDTSevere Thunderstorm WarningMPXLe Sueur, Scott, Sibley66 min
Jun 17, 10:22 PM CDTSevere Thunderstorm WarningMPXChippewa, Kandiyohi, Renville, Swift, Yellow Medicine53 min
Jun 17, 10:42 PM CDTSevere Thunderstorm WarningMPXCarver, Scott, Sibley48 min
Jun 18, 12:21 AM CDTSevere Thunderstorm WarningMPXBenton, Morrison, Sherburne, Stearns54 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

Minneapolis, MN (KMPX), launched 00:00Z, 0.4 hours before the alert went out and 168 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, Minneapolis, MN at 00:00Z on 2011-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1159 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, Minneapolis, MN at 00:00Z on 2011-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 square meters per square second.1939Sfc1 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
1159 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1224 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
187 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.4

Open this sounding in Storm Lab

The text

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

994 
WWUS20 KWNS 180025
SEL6
SPC WW 180025
MNZ000-180700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 496
NWS STORM PREDICTION CENTER NORMAN OK
720 PM CDT FRI JUN 17 2011

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

       PARTS OF WESTERN AND SOUTH CENTRAL MINNESOTA

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 720 PM
UNTIL 200 AM CDT.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTHWEST OF
ALEXANDRIA MINNESOTA TO REDWOOD FALLS MINNESOTA.  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 492...WW 493...WW
494...WW 495...

DISCUSSION...TSTMS EXPECTED TO PERSIST THROUGH LATE EVE INVOF WEAK
WNW-ESE WARM FRONT LOCATED NEAR/A LITTLE N OF THE MN RVR.  OTHER
STORMS MAY MOVE INTO WRN PART OF WW AS FRONTAL CONVECTION MOVES
ENEWD. MODERATE LOW LVL DIRECTIONAL SHEAR...INCREASING LARGE SCALE
ASCENT WITH APPROACH OF ND SHORTWAVE IMPULSE...AND MOIST LOW TO MID
LVL ENVIRONMENT MAY SUPPORT A FEW WEAK SUPERCELLS WITH SUFFICIENT
LOW LVL ROTATION TO YIELD TORNADOES AND PERHAPS LOCALLY DMGG
WIND/MARGINALLY SVR HAIL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.
MEAN STORM MOTION VECTOR 25020.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 17, 7:09 PM CDTSevere Thunderstorm WatchSPCCottonwood, Jackson, Lincoln, Lyon, Murray, Nobles and 2 more3 hr
Jun 17, 9:01 PM CDTMesoscale DiscussionSPCBig Stone, Chippewa, Grant, Kandiyohi, Lac qui Parle, McLeod and 10 more59 min

Nearby

Tornado Watches in Minnesota, 2011Every tornado watch in 2011

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.