Alert archive / Iowa / Tornado Warnings in 2001

Tornado Warning 58, NWS Des Moines, IA

July 24, 2001Polk County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 24, 2001, 4:38 PM CDT for Polk County, Iowa. It was in force for 32 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Jul 24, 2001, 4:38 PM CDT (21:38 UTC)
Expired
Jul 24, 2001, 5:10 PM CDT
In force
32 min
Issued by
NWS Des Moines, IA
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Polk County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 9.6 hours before the alert went out and 235 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 2001-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2087 joules per kilogram.LCLLFCEL10008507005003002001001 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 2001-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.193958Sfc1 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
2087 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
710 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
-13 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

998 
WFUS53 KDMX 242138
TORDSM
IAC153-242210-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
438 PM CDT TUE JUL 24 2001

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL POLK COUNTY IN CENTRAL IOWA
  THIS INCLUDES THE CITY OF DES MOINES

* UNTIL 510 PM CDT

* AT 436 PM...WEATHER SPOTTERS REPORTED A TORNADO 5 MILES SOUTHWEST
  OF DES MOINES...MOVING EAST AT 15 MPH.

* THE TORNADO WILL BE...
  NEAR DES MOINES NOW
  NEAR PLEASANT HILL AROUND 500 PM

THIS REPLACES THE SEVERE THUNDERSTORM WARNING FOR POLK COUNTY. 

IF YOU ARE CAUGHT OUTSIDE...GO TO A NEARBY REINFORCED BUILDING. AS A
LAST RESORT...GET IN A CULVERT OR DITCH AND COVER YOUR HEAD WITH YOUR
HANDS.

LAT...LON 4162 9369 4150 9367 4150 9341 4165 9340

MYERS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 4:09 PM CDTSevere Thunderstorm WarningDMXStory41 min
Jul 24, 4:12 PM CDTSevere Thunderstorm WarningDMXBlack Hawk23 min
Jul 24, 4:18 PM CDTSevere Thunderstorm WarningDMXPolk47 min
Jul 24, 5:24 PM CDTSevere Thunderstorm WarningDMXWarren31 min

Nearby

Tornado Warnings in Iowa, 2001Every tornado warning in 2001Tornadoes in 2001

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.