Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 393, NWS Twin Cities, MN

September 21, 2007Anoka County, Isanti County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 21, 2007, 6:13 AM CDT for Anoka County, Isanti County, Minnesota. It was in force for 22 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 21, 2007, 6:13 AM CDT (11:13 UTC)
Expired
Sep 21, 2007, 6:35 AM CDT
In force
22 min
Issued by
NWS Twin Cities, MN
Area
Counties, with a storm outline in the text

Counties Anoka County, MN, Isanti County, MN

The radar

The Minneapolis radar (KMPX), 80 km from the middle of the area, began a volume at 11:12 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.

The watch it was issued in

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

IssuedProductOfficeLasted
Sep 21, 6:04 AM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 11.2 hours before the alert went out and 81 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 2007-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1394 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2007-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 192 square meters per square second.19395878Sfc1 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
1394 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
838 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
192 m²/s²
0-3 km storm-relative helicity
567 m²/s²
Significant tornado parameter
0.0
Supercell composite
24.8

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KMPX 211113
SVRMPX
MNC003-059-211200-
/O.NEW.KMPX.SV.W.0393.070921T1113Z-070921T1200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
613 AM CDT FRI SEP 21 2007

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

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

* UNTIL 700 AM CDT

* AT 612 AM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM...
  CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS STORM WAS LOCATED 10
  MILES SOUTHWEST OF ISANTI...OR ABOUT 13 MILES SOUTHEAST OF
  PRINCETON...AND MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  ISANTI...
  CAMBRIDGE...
  SAINT FRANCIS...

STAY INDOORS...AND AWAY FROM WINDOWS.

LAT...LON 4566 9314 4556 9314 4555 9303 4536 9303
      4534 9351 4553 9351
TIME...MOT...LOC 1113Z 244DEG 43KT 4543 9341

$$

KAT
2 follow-up statements
000 
WWUS53 KMPX 211126
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
627 AM CDT FRI SEP 21 2007

MNC003-211137-
/O.CAN.KMPX.SV.W.0393.000000T0000Z-070921T1200Z/
ANOKA MN-
627 AM CDT FRI SEP 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR ANOKA COUNTY IS CANCELLED...

THE STORM THAT PROMPTED THE WARNING HAS MOVED NORTH OF THE COUNTY. 
REMAIN ALERT FOR FUTURE STATEMENTS AND ADDITIONAL WARNINGS AS STORMS 
WERE CONTINUING TO DEVELOP SOUTH AND WEST OF THE AREA.

LAT...LON 4566 9314 4556 9314 4555 9303 4542 9303
      4542 9345 4554 9342
TIME...MOT...LOC 1127Z 242DEG 46KT 4560 9313

$$

MNC059-211200-
/O.CON.KMPX.SV.W.0393.000000T0000Z-070921T1200Z/
ISANTI MN-
627 AM CDT FRI SEP 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 AM CDT
FOR ISANTI COUNTY...

AT 621 AM CDT...DOPPLER RADAR CONTINUED TO INDICATE A SEVERE
THUNDERSTORM...CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS STORM WAS
LOCATED NEAR CAMBRIDGE...OR ABOUT OVER ISANTI...AND MOVING NORTHEAST
AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE GRANDY...BODUM...ATHENS...
ISANTI AND CAMBRIDGE.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

LAT...LON 4566 9314 4556 9314 4555 9303 4542 9303
      4542 9345 4554 9342
TIME...MOT...LOC 1127Z 242DEG 46KT 4560 9313

$$

KAT
000 
WWUS53 KMPX 211135
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
635 AM CDT FRI SEP 21 2007

MNC059-211145-
/O.CAN.KMPX.SV.W.0393.000000T0000Z-070921T1200Z/
ISANTI MN-
635 AM CDT FRI SEP 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR ISANTI COUNTY IS CANCELLED...

RADAR INDICATED THAT THE SEVERE THUNDERSTORM HAD MOVED OUT OF THE
WARNED AREA. THUS THE WARNING HAS BEEN CANCELLED.

ADDITIONAL THUNDERSTORMS WILL APPROACH ISANTI COUNTY FROM THE SOUTH 
AND WEST THIS MORNING. REMAIN ALERT FOR FUTURE STATEMENTS AND 
POSSIBLE WARNINGS.

LAT...LON 4566 9314 4556 9314 4555 9303 4542 9303
      4542 9345 4554 9342
TIME...MOT...LOC 1135Z 242DEG 46KT 4564 9300

$$

KAT

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 7:29 PM CDTSevere Thunderstorm WarningMPXAnoka, Washington34 min
Sep 20, 7:56 PM CDTSevere Thunderstorm WarningMPXIsanti38 min
Sep 21, 1:06 AM CDTSevere Thunderstorm WarningMPXDouglas38 min
Sep 21, 1:36 AM CDTSevere Thunderstorm WarningMPXTodd54 min
Sep 21, 4:30 AM CDTWind AdvisoryMPXBenton, Brown, Chippewa, Douglas, Kandiyohi, Lac qui Parle and 15 more10 hr
Sep 21, 5:31 AM CDTSevere Thunderstorm WarningMPXWright44 min
Sep 21, 5:36 AM CDTSevere Thunderstorm WarningMPXChisago, Isanti25 min
Sep 21, 5:45 AM CDTSevere Thunderstorm WarningMPXBenton18 min
Sep 21, 5:59 AM CDTSevere Thunderstorm WarningMPXSherburne17 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2007Every severe thunderstorm warning 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.