Alert archive / Minnesota / Tornado Warnings in 2004

Tornado Warning 29, NWS Twin Cities, MN

August 8, 2004Anoka County, Isanti County, Sherburne County, Minnesota

NWS Twin Cities, MN issued this tornado warning at Aug 8, 2004, 5:42 PM CDT for Anoka County, Isanti County, Sherburne County, Minnesota. It was in force for 63 min. 2 reports 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: Aug 8, 2004, 5:42 PM CDT (22:42 UTC)
Expired: Aug 8, 2004, 6:45 PM CDT
In force: 63 min
Issued by: NWS Twin Cities, MN
Area: Counties, with a storm outline in the text

Counties Anoka County, MN, Isanti County, MN, Sherburne County, MN

The radar

The Minneapolis radar (KMPX), 74 km from the middle of the area, began a volume at 22:43 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
Aug 8, 6:02 PM CDT	HAIL 0.75	5 Se Isanti, MN
Aug 8, 6:02 PM CDT	HAIL 0.75	5 Se Isanti, MN

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
Aug 8, 5:20 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.7 hours before the alert went out and 74 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: 362 J/kg
Mixed-layer CIN: -202 J/kg
Mixed-layer LCL: 1170 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 123 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KMPX 082242
TORMPX
MNC003-059-141-082345-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
541 PM CDT SUN AUG 8 2004

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  ISANTI COUNTY IN EAST CENTRAL MINNESOTA
  EASTERN SHERBURNE COUNTY IN CENTRAL MINNESOTA
  ANOKA COUNTY IN EAST CENTRAL MINNESOTA

* UNTIL 645 PM CDT

* AT 539 PM CDT...TRAINED WEATHER SPOTTERS REPORTED A BRIEF TORNADO  
  TOUCHDOWN 3 MILES EAST OF ZIMMERMAN AT 535 PM.  THE AREA OF THE    
  THUNDERSTORM THAT PRODUCED THE TORNADO CONTINUED TO ROTATE...AND   
  THERE REMAINS A THREAT FOR MORE TORNADO TOUCHDOWNS IN THE AREA.
  THE THUNDERSTORM IS MOVING TO THE EAST AT 25 MPH.

* LOCATIONS IMPACTED INCLUDE...
  CAMBRIDGE.
  ZIMMERMAN.
  ST. FRANCIS.
  CROWN.
  ISANTI.

LAT...LON 4559 9351 4537 9359 4539 9328 4540 9307
      4563 9320

$$

MBK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 8, 3:05 PM CDT	Severe Thunderstorm Warning	MPX	Faribault	40 min
Aug 8, 5:35 PM CDT	Severe Thunderstorm Warning	MPX	Isanti, Sherburne	55 min
Aug 8, 6:22 PM CDT	Severe Thunderstorm Warning	MPX	Chisago	53 min

Nearby

Tornado Warnings in Minnesota, 2004 Every tornado warning in 2004 Tornadoes in 2004

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.