Alert archive / Iowa / Tornado Warnings in 2007

Tornado Warning 48, NWS Des Moines, IA

September 30, 2007Sac County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 30, 2007, 6:03 PM CDT for Sac County, Iowa. It was in force for 15 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, 6:03 PM CDT (23:03 UTC)
Expired
Sep 30, 2007, 6:18 PM CDT
In force
15 min
Issued by
NWS Des Moines, IA
Area
Counties, with a storm outline in the text

County Sac County, IA

The radar

The Des Moines radar (KDMX), 158 km from the middle of the area, began a volume at 23:03 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 30, 1:02 PM CDTTornado WatchSPC7 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.1 hours before the alert went out and 160 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, Omaha, NE at 12:00Z on 2007-09-30Temperature 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, Omaha, NE at 12:00Z on 2007-09-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 450 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
1296 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
450 m²/s²
0-3 km storm-relative helicity
472 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 302302
TORDMX
IAC161-302330-
/O.NEW.KDMX.TO.W.0048.070930T2303Z-070930T2330Z/

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

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN SAC COUNTY IN WEST CENTRAL IOWA...

* UNTIL 630 PM CDT.

* AT 559 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR SCHALLER...
  OR ABOUT 12 MILES SOUTHWEST OF STORM LAKE...MOVING NORTH AT 40 MPH.

* THE TORNADO WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE
  INDICATED COUNTY.

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.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM CDT SUNDAY EVENING FOR
WESTERN IOWA.

LAT...LON 4257 9539 4256 9519 4246 9517 4248 9533
      4248 9540
TIME...MOT...LOC 2303Z 173DEG 35KT 4253 9531

$$
1 follow-up statement
000 
WWUS53 KDMX 302318
SVSDMX

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

IAC161-302328-
/O.CAN.KDMX.TO.W.0048.000000T0000Z-070930T2330Z/
SAC IA-
618 PM CDT SUN SEP 30 2007

...THE TORNADO WARNING FOR NORTHWESTERN SAC COUNTY IS CANCELLED...

AT 616 PM CDT...WEATHER SERVICE DOPPLER RADAR INDICATED THAT THE 
THUNDERSTORMS WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA 
AND NO LONGER POSE AN IMMEDIATE THREAT TO LIFE OR PROPERTY. 
THEREFORE...THE TORNADO WARNING HAS BEEN CANCELLED.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 800 PM CDT SUNDAY EVENING FOR
WESTERN IOWA.

LAT...LON 4257 9539 4256 9519 4246 9517 4248 9533
      4248 9540
TIME...MOT...LOC 2318Z 173DEG 35KT 4267 9533

$$

DONAVON

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 30, 4:29 PM CDTSevere Thunderstorm WarningDMXRinggold31 min
Sep 30, 4:38 PM CDTSevere Thunderstorm WarningDMXUnion27 min
Sep 30, 4:43 PM CDTHigh Wind WarningDMXAdair, Adams, Audubon, Carroll, Cass, Clarke and 8 more3 hr
Sep 30, 4:49 PM CDTSevere Thunderstorm WarningDMXClarke, Madison, Warren56 min
Sep 30, 5:21 PM CDTSevere Thunderstorm WarningDMXClarke, Lucas24 min
Sep 30, 5:23 PM CDTTornado WarningDMXClarke, Lucas24 min
Sep 30, 5:25 PM CDTSevere Thunderstorm WarningDMXSac50 min
Sep 30, 5:33 PM CDTTornado WarningDMXMarion, Warren42 min
Sep 30, 6:03 PM CDTSevere Thunderstorm WarningDMXJasper57 min
Sep 30, 6:17 PM CDTSevere Thunderstorm WarningDMXCalhoun, Pocahontas, Sac43 min
Sep 30, 6:18 PM CDTSevere Thunderstorm WarningDMXMahaska, Marion, Poweshiek42 min
Sep 30, 6:21 PM CDTTornado WarningDMXCalhoun, Pocahontas, Sac24 min
Sep 30, 6:21 PM CDTTornado WarningDMXJasper, Mahaska, Marion, Poweshiek39 min
Sep 30, 6:37 PM CDTTornado WarningDMXPoweshiek38 min
Sep 30, 6:47 PM CDTTornado WarningDMXCalhoun, Pocahontas15 min
Sep 30, 6:54 PM CDTTornado WarningDMXJasper, Mahaska, Marion, Poweshiek26 min

Nearby

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