Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 392, NWS Twin Cities, MN

September 21, 2007Sherburne County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 21, 2007, 5:59 AM CDT for Sherburne County, Minnesota. It was in force for 17 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, 5:59 AM CDT (10:59 UTC)
Expired
Sep 21, 2007, 6:16 AM CDT
In force
17 min
Issued by
NWS Twin Cities, MN
Area
Counties, with a storm outline in the text

County Sherburne County, MN

The radar

The Minneapolis radar (KMPX), 70 km from the middle of the area, began a volume at 10:58 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, 11.0 hours before the alert went out and 69 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 211059
SVRMPX
MNC141-211145-
/O.NEW.KMPX.SV.W.0392.070921T1059Z-070921T1145Z/

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

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SHERBURNE COUNTY IN CENTRAL MINNESOTA...

* UNTIL 645 AM CDT

* AT 554 AM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM...
  CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS STORM WAS LOCATED 6
  MILES EAST OF BECKER...OR ABOUT 18 MILES SOUTHWEST OF PRINCETON...
  AND MOVING NORTHEAST AT 50 MPH.

* LOCATIONS IMPACTED INCLUDE...
  ELK RIVER...
  ZIMMERMAN...

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 4555 9376 4556 9352 4530 9353 4538 9390
TIME...MOT...LOC 1059Z 241DEG 44KT 4537 9368

$$

KAT
1 follow-up statement
000 
WWUS53 KMPX 211116
SVSMPX

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

MNC141-211126-
/O.CAN.KMPX.SV.W.0392.000000T0000Z-070921T1145Z/
SHERBURNE MN-
616 AM CDT FRI SEP 21 2007

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

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

ADDITIONAL THUNDERSTORMS LOCATED TO THE SOUTH AND WEST OF SHERBURNE 
COUNTY ARE EXPECTED TO MOVE INTO THE AREA IN THE NEXT COUPLE OF 
HOURS. REMAIN ALERT FOR FUTURE STATEMENTS AND POSSIBLE WARNINGS.

LAT...LON 4555 9376 4556 9352 4530 9353 4538 9390
TIME...MOT...LOC 1116Z 241DEG 44KT 4547 9342

$$

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, 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.