Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 201, NWS Twin Cities, MN

July 30, 2011Anoka County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 30, 2011, 9:20 PM CDT for Anoka County, Minnesota. It was in force for 55 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 30, 2011, 9:20 PM CDT (02:20 UTC)
Expired: Jul 30, 2011, 10:15 PM CDT
In force: 55 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Anoka County, MN

The radar

The Minneapolis radar (KMPX), 57 km from the middle of the area, began a volume at 02:21 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 was reported inside it

Time	Report	Where	Remark
Jul 30, 9:33 PM CDT	TSTM WND DMG	5 Wnw East Bethel, MN	HALF DOZEN TREES DOWN. SOME UP TO A FOOT IN DIAMETER. TIME ESTIMATED FROM RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 30, 5:31 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 2.3 hours before the alert went out and 58 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: 2387 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 1239 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 176 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 8.4

Open this sounding in Storm Lab

The text

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

590 
WUUS53 KMPX 310220
SVRMPX
MNC003-310315-
/O.NEW.KMPX.SV.W.0201.110731T0220Z-110731T0315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
920 PM CDT SAT JUL 30 2011

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  ANOKA COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 1015 PM CDT

* AT 917 PM CDT...RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS...
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THESE STORMS WERE LOCATED ALONG A LINE EXTENDING FROM
  NORTH BRANCH TO ISANTI TO 6 MILES EAST OF ZIMMERMAN...AND MOVING
  SOUTHEAST AT 25 MPH.

LOCATIONS IN THE WARNING INCLUDE...
  ST FRANCIS...
  EAST BETHEL...
  RAMSEY...
  CEDAR...
  ANDOVER...
  HAM LAKE...
  ANOKA...
  COON RAPIDS...
  OAK PARK...
  CENTERVILLE...
  LINO LAKES...
  BLAINE...
  LEXINGTON...
  CIRCLE PINES...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN THE PATH OF THIS STORM...PREPARE IMMEDIATELY FOR
DAMAGING WINDS IN EXCESS OF 60 MPH AND LARGE HAIL. SEEK SHELTER NOW
INSIDE A STURDY STRUCTURE AND STAY AWAY FROM WINDOWS.

SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE
WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN A STURDY STRUCTURE
SUCH AS A BASEMENT OR SMALL INTERIOR ROOM IF A TORNADO IS SPOTTED.

&&

LAT...LON 4540 9302 4513 9302 4512 9324 4526 9350
      4530 9352 4541 9351 4542 9303
TIME...MOT...LOC 0220Z 325DEG 21KT 4546 9303 4541 9320
          4546 9346
WIND...HAIL 60MPH 1.00IN

$$

2 follow-up statements

401 
WWUS53 KMPX 310244
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
944 PM CDT SAT JUL 30 2011

MNC003-310315-
/O.CON.KMPX.SV.W.0201.000000T0000Z-110731T0315Z/
ANOKA MN-
944 PM CDT SAT JUL 30 2011

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR ANOKA COUNTY
UNTIL 1015 PM CDT...

AT 939 PM CDT...NATIONAL WEATHER SERVICE RADAR INDICATED A LINE OF
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
WINDS UP TO 70 MPH.  THESE STORMS WERE LOCATED ALONG A LINE EXTENDING
FROM STACY TO HAM LAKE TO CEDAR...MOVING SOUTHEAST AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...
  ANDOVER...ANOKA...COON RAPIDS...OAK PARK...LINO LAKES...BLAINE...
  CENTERVILLE...LEXINGTON AND CIRCLE PINES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM HAS A HISTORY OF PRODUCING DESTRUCTIVE WINDS AND LARGE
DAMAGING HAIL. SEEK SHELTER NOW INSIDE A STURDY STRUCTURE AND STAY
AWAY FROM WINDOWS!

&&

LAT...LON 4540 9302 4513 9302 4512 9324 4526 9350
      4530 9352 4541 9351 4542 9303
TIME...MOT...LOC 0244Z 329DEG 30KT 4534 9301 4525 9314
          4526 9333
WIND...HAIL 70MPH 1.00IN

$$

463 
WWUS53 KMPX 310312
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1012 PM CDT SAT JUL 30 2011

MNC003-310327-
/O.EXP.KMPX.SV.W.0201.000000T0000Z-110731T0315Z/
ANOKA MN-
1012 PM CDT SAT JUL 30 2011

...THE SEVERE THUNDERSTORM WARNING FOR ANOKA COUNTY WILL EXPIRE AT
1015 PM CDT...

THE LINE OF STORMS WHICH PROMPTED THE WARNING HAVE WEAKENED BELOW
SEVERE LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR
PROPERTY...HOWEVER SMALL HAIL...GUSTY WINDS AND HEAVY RAIN ARE STILL
POSSIBLE WITH THESE THUNDERSTORMS.

IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A SEVERE
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 100 AM CDT.

LAT...LON 4540 9302 4513 9302 4512 9324 4526 9350
      4530 9352 4541 9351 4542 9303
TIME...MOT...LOC 0312Z 329DEG 30KT 4514 9284 4505 9297
          4506 9316

$$

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 30, 7:10 PM CDT	Tornado Warning	MPX	Todd	50 min
Jul 30, 7:15 PM CDT	Severe Thunderstorm Warning	MPX	Douglas	30 min
Jul 30, 7:28 PM CDT	Areal Flood Advisory	MPX	Todd	3 hr
Jul 30, 7:42 PM CDT	Severe Thunderstorm Warning	MPX	Todd	63 min
Jul 30, 7:45 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec	45 min
Jul 30, 8:01 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs	29 min
Jul 30, 8:15 PM CDT	Severe Thunderstorm Warning	MPX	Stearns	60 min
Jul 30, 8:18 PM CDT	Severe Thunderstorm Warning	MPX	Isanti, Kanabec, Mille Lacs	72 min
Jul 30, 8:22 PM CDT	Tornado Warning	MPX	Isanti, Kanabec, Mille Lacs	38 min
Jul 30, 8:50 PM CDT	Severe Thunderstorm Warning	MPX	Isanti	55 min
Jul 30, 8:53 PM CDT	Tornado Warning	MPX	Isanti	35 min
Jul 30, 8:56 PM CDT	Areal Flood Advisory	MPX	Anoka, Isanti, Kanabec, Mille Lacs, Sherburne	6 hr
Jul 30, 9:07 PM CDT	Severe Thunderstorm Warning	MPX	Kandiyohi, Meeker, Stearns	38 min
Jul 30, 9:48 PM CDT	Special Weather Statement	MPX	McLeod, Meeker	42 min
Jul 30, 9:50 PM CDT	Severe Thunderstorm Warning	MPX	Ramsey, Washington	55 min
Jul 30, 9:54 PM CDT	Areal Flood Advisory	MPX	Anoka, Dakota, Hennepin, Ramsey, Washington	6 hr
Jul 30, 10:21 PM CDT	Severe Thunderstorm Warning	MPX	Anoka	39 min
Jul 30, 11:20 PM CDT	Special Weather Statement	MPX	Le Sueur	40 min
Jul 30, 11:26 PM CDT	Severe Thunderstorm Warning	MPX	Le Sueur, Scott, Sibley	31 min
Jul 30, 11:32 PM CDT	Special Weather Statement	MPX	Goodhue	43 min
Jul 30, 11:55 PM CDT	Severe Thunderstorm Warning	MPX	Goodhue	35 min
Jul 31, 4:00 PM CDT	Heat Advisory	MPX	Anoka, Blue Earth, Brown, Carver, Chippewa, Dakota and 29 more	28 hr

Nearby

Severe Thunderstorm Warnings in Minnesota, 2011 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.