Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 325, NWS Twin Cities, MN

August 21, 2007Freeborn County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 21, 2007, 8:08 PM CDT for Freeborn County, Minnesota. It was in force for 67 min. 1 report 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 21, 2007, 8:08 PM CDT (01:08 UTC)
Expired
Aug 21, 2007, 9:15 PM CDT
In force
67 min
Issued by
NWS Twin Cities, MN
Area
Counties, with a storm outline in the text

County Freeborn County, MN

The radar

The Minneapolis radar (KMPX), 147 km from the middle of the area, began a volume at 01:09 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

TimeReportWhereRemark
Aug 21, 8:40 PM CDTHAIL 1Glenville, MN

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.1 hours before the alert went out and 148 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 2007-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2007-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1298 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
453 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 220108
SVRMPX
MNC047-220215-
/O.NEW.KMPX.SV.W.0325.070822T0108Z-070822T0215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
808 PM CDT TUE AUG 21 2007

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN FREEBORN COUNTY IN SOUTH CENTRAL MINNESOTA...

* UNTIL 915 PM CDT

* AT 806 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM...
  CAPABLE OF PRODUCING NICKEL SIZE HAIL.  THIS STORM WAS LOCATED 30
  MILES SOUTHWEST OF GLENVILLE...OR ABOUT 26 MILES SOUTHEAST OF BLUE
  EARTH...AND MOVING EAST AT 30 MPH.

* LOCATIONS IMPACTED INCLUDE...
  GLENVILLE...

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.

LAT...LON 4356 9364 4337 9380 4351 9304 4364 9303

$$
4 follow-up statements
000 
WWUS53 KMPX 220120
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
818 PM CDT TUE AUG 21 2007

MNC047-220215-
/O.CON.KMPX.SV.W.0325.000000T0000Z-070822T0215Z/
FREEBORN MN-
818 PM CDT TUE AUG 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT 
FOR SOUTHERN FREEBORN COUNTY...

AT 817 PM CDT...DOPPLER RADAR CONTINUED TO INDICATE A SEVERE 
THUNDERSTORM...CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS STORM 
WAS LOCATED 4 MILES EAST OF EMMONS IOWA...OR ABOUT 8 MILES SOUTHWEST 
OF GLENVILLE...AND MOVING NORTHEAST AT 45 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE LONDON...TWIN 
LAKES...MYRTLE...HAYWARD...GLENVILLE...EMMONS...CONGER...AND 
INTERSTATE 35 SOUTH OF ALBERT LEA.

VERY HEAVY RAIN IS EXPECTED WITH THIS STORM. BE ALERT FOR POSSIBLE 
FLOODING.

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 4359 9359 4351 9366 4350 9305 4368 9304
      4364 9342

$$
000 
WWUS53 KMPX 220136
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
832 PM CDT TUE AUG 21 2007

MNC047-220215-
/O.CON.KMPX.SV.W.0325.000000T0000Z-070822T0215Z/
FREEBORN MN-
832 PM CDT TUE AUG 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT 
FOR SOUTHERN FREEBORN COUNTY...

AT 830 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 
CAPABLE OF PRODUCING HALF DOLLAR SIZE HAIL.  THIS STORM WAS LOCATED 
ABOUT OVER GLENVILLE...AND MOVING EAST NORTHEAST AT 40 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE LONDON...TWIN 
LAKES...MYRTLE...HAYWARD...AND INTERSTATE 35 SOUTH OF ALBERT LEA.

VERY HEAVY RAIN IS EXPECTED WITH THIS STORM. BE ALERT FOR POSSIBLE 
FLOODING.

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM. 
WHILE THE ENVIRONMENT IS NOT FAVORABLE FOR A TORNADO...ONE MAY STILL 
DEVELOP. IF A TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE 
OF SAFETY IN A STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL 
INTERIOR ROOM.

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 4358 9356 4351 9362 4350 9305 4374 9305
      4370 9317 4364 9342

$$
000 
WWUS53 KMPX 220159
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
857 PM CDT TUE AUG 21 2007

MNC047-220215-
/O.CON.KMPX.SV.W.0325.000000T0000Z-070822T0215Z/
FREEBORN MN-
857 PM CDT TUE AUG 21 2007

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM CDT 
FOR SOUTHERN FREEBORN COUNTY...

AT 855 PM CDT...DOPPLER RADAR INDICATED THE INITIAL SEVERE 
THUNDERSTORM HAS MOVED EAST OUT OF FREEBORN COUNTY. 
HOWEVER...ANOTHER INTENSIFYING THUNDERSTORM WAS MOVING EAST 
NORTHEAST FROM WORTH COUNTY IOWA AND WILL BE CAPABLE OF PRODUCING 
PENNY SIZE HAIL AS IT MOVES ACROSS FAR SOUTHEAST FREEBORN COUNTY.  
THIS STORM WAS LOCATED 12 MILES SOUTH OF GLENVILLE...OR ABOUT 7 
MILES WEST OF NORTHWOOD IOWA...AND MOVING EAST NORTHEAST AT 50 MPH.

OTHER LOCATIONS IN THE WARNING INCLUDE LONDON...MYRTLE AND GLENVILLE.

LAT...LON 4364 9322 4350 9342 4350 9305 4371 9305

$$
000 
WWUS53 KMPX 220214
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
912 PM CDT TUE AUG 21 2007

MNC047-220222-
/O.EXP.KMPX.SV.W.0325.000000T0000Z-070822T0215Z/
FREEBORN MN-
912 PM CDT TUE AUG 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN FREEBORN COUNTY 
EXPIRES AT 915 PM CDT...

AT 912 PM CDT...DOPPLER RADAR INDICATED THAT SEVERE THUNDERSTORMS 
HAD MOVED OUT OF THE COUNTY. HOWEVER...MORE THUNDERSTORMS WERE 
DEVELOPING IN THE AREA...REMAIN ALERT FOR POSSIBLE ADDITIONAL 
WARNINGS. ALSO...FLOODING WILL REMAIN A CONCERN THROUGH THE REST OF 
THE EVENING AS THUNDERSTORMS TRACK OVER THE SATURATED GROUND.

AT 840 PM CDT...HAIL OF QUARTER SIZE WAS REPORTED JUST SOUTH OF 
GLENVILLE WITH THE STORM. REPORT ANY SEVERE WEATHER TO YOUR LOCAL 
LAW ENFORCEMENT FOR RELAY TO THE NATIONAL WEATHER SERVICE.

LAT...LON 4364 9322 4350 9342 4350 9305 4371 9305

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 7:06 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Le Sueur, Rice, Waseca37 min
Aug 21, 8:42 PM CDTFlash Flood WarningMPXFaribault, Freeborn3 hr
Aug 22, 3:21 AM CDTFlash Flood WatchMPXBlue Earth, Brown, Faribault, Freeborn, Goodhue, Le Sueur and 6 more33 hr
Aug 22, 3:25 AM CDTDense Fog AdvisoryMPXAnoka, Benton, Blue Earth, Brown, Carver, Chippewa and 36 more7 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.