Alert archive / Iowa / Tornado Warnings in 2004

Tornado Warning 117, NWS Des Moines, IA

September 5, 2004Hamilton County, Webster County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 5, 2004, 6:50 PM CDT for Hamilton County, Webster County, Iowa. It was in force for 25 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, 6:50 PM CDT (23:50 UTC)
Expired: Sep 5, 2004, 7:15 PM CDT
In force: 25 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

Counties Hamilton County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 75 km from the middle of the area, began a volume at 23:52 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.

Issued	Product	Office	Lasted
Sep 5, 3:00 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.8 hours before the alert went out and 232 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: 231 J/kg
Mixed-layer CIN: -106 J/kg
Mixed-layer LCL: 1212 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 127 m²/s²
0-3 km storm-relative helicity: 117 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

699 
WFUS53 KDMX 052350
TORDMX
IAC079-187-060015-
/X.NEW.KDMX.TO.W.0007.040905T2350Z-040906T0015Z/

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

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTHWESTERN HAMILTON COUNTY IN CENTRAL IOWA.
  SOUTHEASTERN WEBSTER COUNTY IN CENTRAL IOWA.

* UNTIL 715 PM CDT.

* AT 647 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 13 MILES SOUTHWEST OF WEBSTER CITY...OR 19 MILES
  SOUTHEAST OF FORT DODGE...AND MOVING NORTHEAST AT 40 MPH.

* THIS TORNADIC STORM WILL BE...
  NEAR WEBSTER CITY BY 705 PM CDT.

THE TOWNS OF STRATFORD AND WEBSTER CITY MUNICIPAL 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 4221 9416 4221 9394 4255 9369 4256 9388
      4256 9397

$$

BOKSA

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 5, 3:32 PM CDT	Tornado Warning	DMX	Crawford	43 min
Sep 5, 4:41 PM CDT	Severe Thunderstorm Warning	DMX	Cass	34 min
Sep 5, 5:02 PM CDT	Severe Thunderstorm Warning	DMX	Adair	43 min
Sep 5, 5:55 PM CDT	Severe Thunderstorm Warning	DMX	Webster	35 min
Sep 5, 6:04 PM CDT	Tornado Warning	DMX	Greene	26 min
Sep 5, 6:27 PM CDT	Tornado Warning	DMX	Boone, Story	33 min
Sep 5, 6:33 PM CDT	Tornado Warning	DMX	Greene, Webster	27 min
Sep 5, 6:37 PM CDT	Tornado Warning	DMX	Madison	38 min
Sep 5, 6:46 PM CDT	Tornado Warning	DMX	Union	29 min
Sep 5, 6:58 PM CDT	Tornado Warning	DMX	Story	32 min

Nearby

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