Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 397, NWS Twin Cities, MN

September 24, 2007Chisago County, Isanti County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 24, 2007, 5:22 PM CDT for Chisago County, Isanti County, Minnesota. It was in force for 38 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 24, 2007, 5:22 PM CDT (22:22 UTC)
Expired
Sep 24, 2007, 6:00 PM CDT
In force
38 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), 87 km from the middle of the area, began a volume at 22:22 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 24, 4:57 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.4 hours before the alert went out and 88 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 12:00Z on 2007-09-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 176 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 12:00Z on 2007-09-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 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
176 J/kg
Mixed-layer CIN
-72 J/kg
Mixed-layer LCL
899 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
90 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 
WUUS53 KMPX 242222
SVRMPX
MNC025-059-242300-
/O.NEW.KMPX.SV.W.0397.070924T2222Z-070924T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
522 PM CDT MON SEP 24 2007

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

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

* UNTIL 600 PM CDT

* AT 518 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM...
  CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 65 MPH.  THIS
  STORM WAS LOCATED 5 MILES SOUTH OF ISANTI...OR ABOUT 10 MILES SOUTH
  OF CAMBRIDGE...AND MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  CAMBRIDGE...
  NORTH BRANCH...
  BRAHAM...
  RUSH CITY...
  ISANTI...
  HARRIS...

STAY INDOORS...AND AWAY FROM WINDOWS.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT
TUESDAY MORNING FOR SOUTHEASTERN MINNESOTA AND NORTHWESTERN
WISCONSIN.

LAT...LON 4542 9295 4542 9338 4573 9319 4573 9285
TIME...MOT...LOC 2222Z 221DEG 46KT 4546 9318

$$
1 follow-up statement
000 
WWUS53 KMPX 242248
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
549 PM CDT MON SEP 24 2007

MNC025-242300-
/O.CON.KMPX.SV.W.0397.000000T0000Z-070924T2300Z/
CHISAGO MN-
549 PM CDT MON SEP 24 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM CDT
FOR CHISAGO COUNTY...

AT 544 PM CDT...DOPPLER RADAR CONTINUED TO INDICATE A SEVERE
THUNDERSTORM...CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 65
MPH.  THIS STORM WAS LOCATED 4 MILES SOUTHEAST OF HARRIS...OR ABOUT 5
MILES NORTHEAST OF NORTH BRANCH...AND MOVING NORTHEAST AT 45 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE RUSH CITY...NORTH BRANCH...
HARRIS AND BRANCH.

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 4564 9287 4564 9289 4558 9289 4557 9291
      4553 9291 4543 9294 4542 9300 4572 9303
      4573 9285
TIME...MOT...LOC 2249Z 225DEG 41KT 4562 9287

$$

RAH

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 24, 4:28 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Le Sueur, Nicollet47 min
Sep 24, 4:35 PM CDTSevere Thunderstorm WarningMPXMcLeod25 min
Sep 24, 5:03 PM CDTSevere Thunderstorm WarningMPXScott42 min
Sep 24, 5:33 PM CDTSevere Thunderstorm WarningMPXDakota42 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.