Alert archive / Iowa / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 64, NWS Des Moines, IA

May 5, 2002Palo Alto County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 5, 2002, 8:07 PM CDT for Palo Alto County, Iowa. It was in force for 38 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: May 5, 2002, 8:07 PM CDT (01:07 UTC)
Expired: May 5, 2002, 8:45 PM CDT
In force: 38 min
Issued by: NWS Des Moines, IA
Area: Counties, with a storm outline in the text

County Palo Alto County, IA

The radar

The Sioux Falls radar (KFSD), 169 km from the middle of the area, began a volume at 01:10 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
May 5, 4:30 PM CDT	Tornado Watch	SPC	7 hr
May 5, 8:00 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 1.1 hours before the alert went out and 241 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: 1550 J/kg
Mixed-layer CIN: -10 J/kg
Mixed-layer LCL: 1621 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 166 m²/s²
Significant tornado parameter: 0.4
Supercell composite: 5.0

Open this sounding in Storm Lab

The text

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

000 
WUUS53 KDMX 060107
SVRDSM
IAC147-060145-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
807 PM CDT SUN MAY 5 2002

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  PALO ALTO COUNTY IN NORTHWEST IOWA

* UNTIL 845 PM CDT

* AT 804 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 5 MILES SOUTH OF GRAETTINGER...OR ABOUT 19
  MILES EAST OF SPENCER...MOVING EAST AT 35 MPH.

* THE SEVERE THUNDERSTORM WILL BE...

  8 MILES NORTH OF CYLINDER AROUND 820 PM.

REMEMBER...SEVERE THUNDERSTORMS CAN PRODUCE TORNADOES WITH LITTLE OR
NO ADVANCE WARNING.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM SUNDAY EVENING FOR
NORTHWESTERN IOWA.

A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL MIDNIGHT MONDAY
MORNING FOR NORTHWESTERN IOWA. A SEVERE THUNDERSTORM WATCH ALSO
REMAINS IN EFFECT UNTIL 100 AM MONDAY MORNING FOR IOWA.

LAT...LON 4325 9492 4292 9490 4293 9448 4323 9449

JOHNSON

The office that day

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

Issued	Product	Office	Counties	Lasted
May 5, 7:15 PM CDT	Severe Thunderstorm Warning	DMX	Audubon	45 min
May 5, 7:28 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	47 min
May 5, 8:01 PM CDT	Severe Thunderstorm Warning	DMX	Sac	44 min
May 5, 8:06 PM CDT	Severe Thunderstorm Warning	DMX	Emmet	39 min
May 5, 8:14 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	46 min
May 5, 8:23 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth	52 min
May 5, 8:36 PM CDT	Severe Thunderstorm Warning	DMX	Greene	54 min
May 5, 8:41 PM CDT	Severe Thunderstorm Warning	DMX	Carroll	64 min
May 5, 8:47 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	28 min
May 5, 9:11 PM CDT	Severe Thunderstorm Warning	DMX	Sac	34 min
May 5, 9:33 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Pocahontas	42 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2002 Every severe thunderstorm warning in 2002

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.