Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 389, NWS Twin Cities, MN

September 21, 2007Chisago County, Isanti County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 21, 2007, 5:36 AM CDT for Chisago County, Isanti County, Minnesota. It was in force for 25 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, 5:36 AM CDT (10:36 UTC)
Expired
Sep 21, 2007, 6:01 AM CDT
In force
25 min
Issued by
NWS Twin Cities, MN
Area
Counties, with a storm outline in the text

Counties Chisago County, MN, Isanti County, MN

The radar

The Minneapolis radar (KMPX), 92 km from the middle of the area, began a volume at 10:35 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, 12:00 AM CDTTornado WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 10.6 hours before the alert went out and 94 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 211036
SVRMPX
MNC025-059-211115-
/O.NEW.KMPX.SV.W.0389.070921T1036Z-070921T1115Z/

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

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN ISANTI COUNTY IN EAST CENTRAL MINNESOTA...
  CHISAGO COUNTY IN EAST CENTRAL MINNESOTA...

* UNTIL 615 AM CDT

* AT 531 AM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM...
  CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS STORM WAS LOCATED 7
  MILES SOUTHWEST OF NORTH BRANCH...OR ABOUT 10 MILES SOUTHEAST OF
  CAMBRIDGE...AND MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  NORTH BRANCH...
  INTERSTATE 35 FROM NORTH BRANCH TO RUSH CITY...

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.

STAY INDOORS...AND AWAY FROM WINDOWS.

LAT...LON 4573 9309 4556 9286 4556 9276 4547 9269
      4541 9302 4545 9318
TIME...MOT...LOC 1036Z 245DEG 47KT 4548 9300

$$

KAT
2 follow-up statements
000 
WWUS53 KMPX 211049
SVSMPX

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

MNC059-211058-
/O.CAN.KMPX.SV.W.0389.000000T0000Z-070921T1115Z/
ISANTI MN-
548 AM CDT FRI SEP 21 2007

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

THE STORM THAT PROMPTED THE WARNING HAS MOVED EASTWARD INTO CHISAGO 
COUNTY.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 700 AM CDT FRIDAY MORNING FOR
CENTRAL MINNESOTA.

LAT...LON 4547 9269 4546 9296 4559 9301 4558 9287
      4556 9287 4556 9286 4556 9276
TIME...MOT...LOC 1048Z 245DEG 47KT 4554 9279

$$

MNC025-211115-
/O.CON.KMPX.SV.W.0389.000000T0000Z-070921T1115Z/
CHISAGO MN-
548 AM CDT FRI SEP 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 AM CDT
FOR CHISAGO COUNTY...

AT 545 AM CDT...DOPPLER RADAR CONTINUED TO INDICATE A SEVERE
THUNDERSTORM...CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS STORM WAS
LOCATED 6 MILES EAST OF BRANCH...AND MOVING NORTHEAST AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE NORTH BRANCH...AND THE 
SECTION OF INTERSTATE 35 NEAR NORTH BRANCH.

LAT...LON 4547 9269 4546 9296 4559 9301 4558 9287
      4556 9287 4556 9286 4556 9276
TIME...MOT...LOC 1048Z 245DEG 47KT 4554 9279

$$

KAT
000 
WWUS53 KMPX 211101
SVSMPX

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

MNC025-211111-
/O.CAN.KMPX.SV.W.0389.000000T0000Z-070921T1115Z/
CHISAGO MN-
601 AM CDT FRI SEP 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR CHISAGO 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 BE APPROACHING CHISAGO COUNTY FROM THE 
WEST. REMAIN ALERT FOR FUTURE STATEMENTS AND POSSIBLE WARNINGS.

LAT...LON 4547 9269 4546 9296 4559 9301 4558 9287
      4556 9287 4556 9286 4556 9276
TIME...MOT...LOC 1101Z 245DEG 47KT 4561 9257

$$

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, 5:45 AM CDTSevere Thunderstorm WarningMPXBenton18 min
Sep 21, 5:59 AM CDTSevere Thunderstorm WarningMPXSherburne17 min
Sep 21, 6:13 AM CDTSevere Thunderstorm WarningMPXAnoka, Isanti22 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.