Alert archive / Iowa / Tornado Warnings in 2004

Tornado Warning 124, NWS Des Moines, IA

September 5, 2004Story County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 5, 2004, 8:17 PM CDT for Story County, Iowa. It was in force for 43 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 5, 2004, 8:17 PM CDT (01:17 UTC)
Expired
Sep 5, 2004, 9:00 PM CDT
In force
43 min
Issued by
NWS Des Moines, IA
Area
Counties, with a storm outline in the text

County Story County, IA

The radar

The Des Moines radar (KDMX), 34 km from the middle of the area, began a volume at 01:17 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 5, 3:00 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.3 hours before the alert went out and 246 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 00:00Z on 2004-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 joules per kilogram.LCLLFCEL10008507005003002001001 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, Omaha, NE at 00:00Z on 2004-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
8 J/kg
Mixed-layer CIN
-124 J/kg
Mixed-layer LCL
1414 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

221 
WFUS53 KDMX 060117
TORDMX
IAC169-060200-
/X.NEW.KDMX.TO.W.0014.040906T0117Z-040906T0200Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
817 PM CDT SUN SEP 5 2004

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

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

* UNTIL 900 PM CDT.

* AT 813 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED NEAR HUXLEY...OR 22 MILES NORTH OF DES MOINES...
  AND MOVING NORTH AT 25 MPH.

* THIS TORNADIC STORM WILL BE...
  NEAR AMES BY 830 PM CDT.
  6 MILES WEST OF NEVADA BY 835 PM CDT.
  6 MILES SOUTHEAST OF STORY CITY BY 855 PM CDT.

THE TOWNS OF SLATER...CAMBRIDGE...KELLEY...AMES MUNICIPAL AIRPORT...
GILBERT...ROLAND AND MCCALLSBURG ARE ALSO IN THE PATH OF THIS
TORNADIC STORM.

WHEN A TORNADO WARNING IS ISSUED BASED ON DOPPLER RADAR...IT MEANS
THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY
ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. IF YOU
ARE IN THE PATH OF THIS DANGEROUS STORM...MOVE INDOORS AND TO THE
LOWEST LEVEL OF THE BUILDING. STAY AWAY FROM WINDOWS. IF DRIVING...DO
NOT SEEK SHELTER UNDER A HIGHWAY OVERPASS.

LAT...LON 4187 9370 4187 9333 4221 9334 4221 9371

$$

BOKSA

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 5, 7:15 PM CDTTornado WarningDMXHamilton, Wright30 min
Sep 5, 7:16 PM CDTTornado WarningDMXMadison29 min
Sep 5, 7:28 PM CDTTornado WarningDMXHardin, Story47 min
Sep 5, 7:39 PM CDTTornado WarningDMXWarren36 min
Sep 5, 7:56 PM CDTTornado WarningDMXPolk49 min
Sep 5, 8:44 PM CDTTornado WarningDMXLucas, Warren31 min
Sep 5, 8:48 PM CDTTornado WarningDMXJasper, Polk27 min
Sep 5, 9:03 PM CDTTornado WarningDMXMarshall, Story42 min

Nearby

Tornado Warnings in Iowa, 2004Every tornado warning in 2004Tornadoes in 2004

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.