Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 55, NWS Des Moines, IA

September 30, 2007Poweshiek County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 30, 2007, 7:14 PM CDT for Poweshiek County, Iowa. It was in force for 24 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 30, 2007, 7:14 PM CDT (00:14 UTC)
Expired: Sep 30, 2007, 7:38 PM CDT
In force: 24 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon

County Poweshiek County, IA

The radar

The Des Moines radar (KDMX), 91 km from the middle of the area, began a volume at 00:16 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 nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.2 hours before the alert went out and 177 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2149 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 116 m²/s²
0-3 km storm-relative helicity: 191 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 KDMX 010014
TORDMX
IAC157-010045-
/O.NEW.KDMX.TO.W.0055.071001T0014Z-071001T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
714 PM CDT SUN SEP 30 2007

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  POWESHIEK COUNTY IN CENTRAL IOWA...

* UNTIL 745 PM CDT.

* AT 712 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 10 MILES SOUTH
  OF GRINNELL...OR ABOUT 33 MILES NORTHWEST OF SIGOURNEY...MOVING
  NORTHEAST AT 50 MPH.

* THE TORNADO WILL BE NEAR...
  6 MILES SOUTHEAST OF GRINNELL BY 720 PM CDT...
  BROOKLYN BY 730 PM CDT...

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 181 AND 197.

SPOTTERS REPORTED ROTATION IN THE CLOUDS SOUTH OF LYNNVILLE AT 610 
PM CDT.

THIS IS A HAZARDOUS SITUATION. SEEK SHELTER IN A BASEMENT...OR IN AN
INTERIOR ROOM. STAY AWAY FROM WINDOWS. IF YOU ARE OUTSIDE OR IN A
CAR...SEEK SHELTER IN A REINFORCED BUILDING.

LAT...LON 4160 9276 4161 9277 4171 9277 4187 9259
      4186 9230 4180 9229 4151 9267 4152 9275
TIME...MOT...LOC 0014Z 222DEG 47KT 4162 9271

$$

SMALL

2 follow-up statements

000 
WWUS53 KDMX 010030
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
729 PM CDT SUN SEP 30 2007

IAC157-010045-
/O.CON.KDMX.TO.W.0055.000000T0000Z-071001T0045Z/
POWESHIEK IA-
729 PM CDT SUN SEP 30 2007

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR POWESHIEK
COUNTY...

AT 725 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A POSSIBLE TORNADO.  THIS STORM WAS LOCATED NEAR 
SEARSBORO...OR ABOUT 31 MILES NORTHWEST OF SIGOURNEY...MOVING 
NORTHEAST AT 30 MPH.

THE TORNADO WILL BE NEAR...
  7 MILES SOUTHEAST OF GRINNELL BY 735 PM CDT...
  MALCOM AND 6 MILES WEST OF BROOKLYN BY 745 PM CDT...

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 181 AND 198.

SEEK SHELTER IN A BASEMENT...OR IN AN INTERIOR ROOM. STAY AWAY FROM
WINDOWS. IF YOU ARE IN A CAR OR OUTSIDE...SEEK SHELTER IN A
REINFORCED BUILDING.

THIS STORM HAS WEAKENED SOME AND MAY END BEING CANCELLED EARLY.

REPORT TORNADOES...WIND IN EXCESS OF 50 MPH...HAIL LARGER THAN ONE
HALF INCH...OR STORM DAMAGE BY CALLING LOCAL LAW ENFORCEMENT AND
ASKING THEM TO RELAY THE REPORT TO THE NATIONAL WEATHER SERVICE.

LAT...LON 4160 9276 4161 9277 4171 9277 4187 9259
      4186 9230 4180 9229 4151 9267 4152 9275
TIME...MOT...LOC 0029Z 222DEG 26KT 4163 9266

$$

SMALL

000 
WWUS53 KDMX 010038
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
735 PM CDT SUN SEP 30 2007

IAC157-010045-
/O.CAN.KDMX.TO.W.0055.000000T0000Z-071001T0045Z/
POWESHIEK IA-
735 PM CDT SUN SEP 30 2007

...THE TORNADO WARNING FOR POWESHIEK COUNTY IS CANCELLED...

AT 733 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE 
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE EITHER WEAKENED...AND 
NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY. 
THEREFORE...THE TORNADO WARNING HAS BEEN CANCELLED.

LAT...LON 4160 9276 4161 9277 4171 9277 4187 9259
      4186 9230 4180 9229 4151 9267 4152 9275
TIME...MOT...LOC 0035Z 222DEG 26KT 4166 9262

$$

SMALL

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 30, 7:03 PM CDT	Tornado Warning	DMX	Tama	27 min
Sep 30, 7:33 PM CDT	Tornado Warning	DMX	Kossuth, Palo Alto	27 min

Nearby

Tornado Warnings in Iowa, 2007 Every tornado warning in 2007 Tornadoes 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.