Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 51, NWS Des Moines, IA

September 30, 2007Poweshiek County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 30, 2007, 6:37 PM CDT for Poweshiek County, Iowa. It was in force for 38 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: Sep 30, 2007, 6:37 PM CDT (23:37 UTC)
Expired: Sep 30, 2007, 7:15 PM CDT
In force: 38 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

County Poweshiek County, IA

The radar

The Des Moines radar (KDMX), 85 km from the middle of the area, began a volume at 23:38 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

Time	Report	Where	Remark
Sep 30, 6:51 PM CDT	TORNADO	3 Nnw Malcom, IA	EXTENSIVE DAMAGE TO FARMSTED...AT LEAST 3 BARNS DESTROYED...3 TO 4 EMPTY GRAIN BINS...AND SEVERAL 1 TO 2 FOOT DIAMETER TREES SNAPPED IN HALF. DIMENSIONS OF BARNS WERE 20 BY 30 FOOT...20 BY 40 FOOT...AND A MACHINE SHED WITH DIMENSIONS OF 60 BY 100 FEET WERE ALL

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

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.6 hours before the alert went out and 183 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: 1947 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 154 m²/s²
0-3 km storm-relative helicity: 128 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 302336
TORDMX
IAC157-010015-
/O.NEW.KDMX.TO.W.0051.070930T2337Z-071001T0015Z/

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

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

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

* UNTIL 715 PM CDT.

* AT 633 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 11 MILES SOUTH
  OF GRINNELL...OR ABOUT 34 MILES NORTHWEST OF SIGOURNEY...MOVING
  NORTHEAST AT 40 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  GRINNELL AIRPORT.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 181 AND 184.

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.

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 4166 9277 4172 9277 4173 9277 4175 9277
      4176 9277 4186 9268 4186 9230
TIME...MOT...LOC 2337Z 217DEG 38KT 4162 9272

$$

SMALL

1 follow-up statement

000 
WWUS53 KDMX 010007
SVSDMX

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

IAC157-010016-
/O.EXP.KDMX.TO.W.0051.000000T0000Z-071001T0015Z/
POWESHIEK IA-
706 PM CDT SUN SEP 30 2007

...THE TORNADO WARNING FOR NORTHERN POWESHIEK COUNTY EXPIRES AT 715
PM CDT...

AT 703 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE
THUNDERSTORMS WHICH PROMPTED THE WARNING HAVE MOVED OUT OF THE AREA.
THEREFORE...THE TORNADO WARNING HAS BEEN ALLOWED TO EXPIRE.

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 4166 9277 4172 9277 4173 9277 4175 9277
      4176 9277 4186 9268 4186 9230
TIME...MOT...LOC 0006Z 217DEG 38KT 4186 9247

$$

SMALL

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 30, 4:29 PM CDT	Severe Thunderstorm Warning	DMX	Ringgold	31 min
Sep 30, 4:38 PM CDT	Severe Thunderstorm Warning	DMX	Union	27 min
Sep 30, 4:43 PM CDT	High Wind Warning	DMX	Adair, Adams, Audubon, Carroll, Cass, Clarke and 8 more	3 hr
Sep 30, 4:49 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Madison, Warren	56 min
Sep 30, 5:21 PM CDT	Severe Thunderstorm Warning	DMX	Clarke, Lucas	24 min
Sep 30, 5:23 PM CDT	Tornado Warning	DMX	Clarke, Lucas	24 min
Sep 30, 5:25 PM CDT	Severe Thunderstorm Warning	DMX	Sac	50 min
Sep 30, 5:33 PM CDT	Tornado Warning	DMX	Marion, Warren	42 min
Sep 30, 6:03 PM CDT	Severe Thunderstorm Warning	DMX	Jasper	57 min
Sep 30, 6:03 PM CDT	Tornado Warning	DMX	Sac	15 min
Sep 30, 6:17 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Pocahontas, Sac	43 min
Sep 30, 6:18 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Marion, Poweshiek	42 min
Sep 30, 6:21 PM CDT	Tornado Warning	DMX	Calhoun, Pocahontas, Sac	24 min
Sep 30, 6:21 PM CDT	Tornado Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	39 min
Sep 30, 6:47 PM CDT	Tornado Warning	DMX	Calhoun, Pocahontas	15 min
Sep 30, 6:54 PM CDT	Tornado Warning	DMX	Jasper, Mahaska, Marion, Poweshiek	26 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.