Alert archive / Minnesota / Severe Thunderstorm Warnings in 2007

Severe Thunderstorm Warning 13, NWS Twin Cities, MN

April 21, 2007Chisago County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Apr 21, 2007, 12:16 PM CDT for Chisago County, Minnesota. It was in force for 44 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
Apr 21, 2007, 12:16 PM CDT (17:16 UTC)
Expired
Apr 21, 2007, 1:00 PM CDT
In force
44 min
Issued by
NWS Twin Cities, MN
Area
Counties, with a storm outline in the text

County Chisago County, MN

The radar

The Minneapolis radar (KMPX), 96 km from the middle of the area, began a volume at 17:19 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
Apr 21, 12:48 PM CDTHAIL 0.754 W Rush City, 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 12:00Z, 5.3 hours before the alert went out and 97 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 2007-04-21Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 2007-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 341 square meters per square second.193958Sfc1 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
1697 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
341 m²/s²
0-3 km storm-relative helicity
335 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 211716
SVRMPX
MNC025-211800-
/O.NEW.KMPX.SV.W.0013.070421T1716Z-070421T1800Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1216 PM CDT SAT APR 21 2007

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A

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

* UNTIL 100 PM CDT

* AT 1215 PM CDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM...
  CAPABLE OF PRODUCING   THIS STORM WAS LOCATED 5 MILES NORTHWEST OF
  NORTH BRANCH...OR ABOUT 8 MILES EAST OF CAMBRIDGE...AND MOVING
  NORTHEAST AT 45 MPH.

* LOCATIONS IMPACTED INCLUDE...
  NORTH BRANCH...
  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.

LAT...LON 4561 9308 4544 9305 4559 9286 4572 9288
      4573 9312

$$
RJN
1 follow-up statement
000 
WWUS53 KMPX 211756
SVSMPX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1255 PM CDT SAT APR 21 2007

MNC025-211815-
/O.EXP.KMPX.SV.W.0013.000000T0000Z-070421T1800Z/
CHISAGO MN-
1255 PM CDT SAT APR 21 2007

...THE SEVERE THUNDERSTORM WARNING FOR CHISAGO COUNTY EXPIRES AT 100
PM CDT...

SEVERE STORMS HAVE BEGUN WEAKENING...AND ARE MOVING NORTHEAST OUT OF 
CHISAGO COUNTY. ONLY PEA SIZE HAIL IS EXPECTED WITH THE REMAINING 
STORMS THROUGH 115 PM.

LAT...LON 4561 9308 4544 9305 4559 9286 4572 9288
      4573 9312

$$
RJN

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 21, 3:46 AM CDTWind AdvisoryMPXBlue Earth, Brown, Faribault, Freeborn, Martin, Redwood and 4 more16 hr
Apr 21, 6:12 AM CDTSevere Thunderstorm WarningMPXStearns40 min
Apr 21, 9:47 AM CDTSevere Thunderstorm WarningMPXMcLeod, Meeker, Renville, Sibley, Wright58 min
Apr 21, 11:31 AM CDTSevere Thunderstorm WarningMPXSherburne29 min
Apr 21, 11:57 AM CDTSevere Thunderstorm WarningMPXIsanti33 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.