Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 199, NWS Des Moines, IA

June 23, 1998Cerro Gordo County, Franklin County, Worth County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at Jun 23, 1998, 11:34 PM CDT for Cerro Gordo County, Franklin County, Worth County, Iowa. It was in force for 31 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jun 23, 1998, 11:34 PM CDT (04:34 UTC)
Expired: Jun 24, 1998, 12:05 AM CDT
In force: 31 min
Issued by: NWS Des Moines, IA
Area: Whole counties

Counties Cerro Gordo County, IA, Franklin County, IA, Worth County, IA

The radar

The Des Moines radar (KDMX), 153 km from the middle of the area, began a volume at 04:38 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.

What was reported inside it

Time	Report	Where	Remark
Jun 23, 11:36 PM CDT	Thunderstorm Wind 63	Mason City, IA
Jun 23, 11:50 PM CDT	Thunderstorm Wind 69	Clear Lake, IA

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jun 23, 7:30 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 4.6 hours before the alert went out and 200 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: 901 J/kg
Mixed-layer CIN: -26 J/kg
Mixed-layer LCL: 1105 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 212 m²/s²
0-3 km storm-relative helicity: 335 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 8.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 240434 RRA
SVRDSM
IAC033-069-195-240505-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
1134 PM CDT TUE JUN 23 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CERRO GORDO COUNTY IN NORTH CENTRAL IOWA
  FRANKLIN COUNTY IN NORTH CENTRAL IOWA
  WORTH COUNTY IN NORTH CENTRAL IOWA

* UNTIL 1205 AM CDT

* AT 1132 PM CDT... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 10
  MILES SOUTHWEST OF MASON CITY OR 8 MILES WEST NORTHWEST OF
  ROCKWELL MOVING EAST NORTHEAST AT 40 MPH.

* THIS STORM CAN BE EXPECTED NEAR...
   NORTHWOOD          BY 1135 PM CDT
   MASON CITY         BY 1135 PM CDT
   HAMPTON            BY 1141 PM CDT
   PLYMOUTH           BY 1144 PM CDT
   ROCK FALLS         BY 1145 PM CDT

GO INSIDE A STURDY BUILDING AND STAY AWAY FROM WINDOWS! A TORNADO
WATCH IS IN EFFECT. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO
PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING.

BRF

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 23, 8:59 PM CDT	Severe Thunderstorm Warning	DMX	Sac	46 min
Jun 23, 9:25 PM CDT	Severe Thunderstorm Warning	DMX	Crawford	30 min
Jun 23, 9:47 PM CDT	Tornado Warning	DMX	Sac	33 min
Jun 23, 9:52 PM CDT	Tornado Warning	DMX	Calhoun	33 min
Jun 23, 10:08 PM CDT	Severe Thunderstorm Warning	DMX	Calhoun, Carroll	47 min
Jun 23, 10:17 PM CDT	Severe Thunderstorm Warning	DMX	Webster	33 min
Jun 23, 10:19 PM CDT	Flash Flood Warning	DMX	Palo Alto	3 hr
Jun 23, 10:38 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	32 min
Jun 23, 10:41 PM CDT	Flash Flood Warning	DMX	Kossuth	4 hr
Jun 23, 10:41 PM CDT	Flash Flood Warning	DMX	Sac	4 hr
Jun 23, 10:54 PM CDT	Flash Flood Warning	DMX	Pocahontas	4 hr
Jun 23, 11:20 PM CDT	Flash Flood Warning	DMX	Crawford	4 hr
Jun 23, 11:31 PM CDT	Flash Flood Warning	DMX	Winnebago	4 hr
Jun 23, 11:53 PM CDT	Flash Flood Warning	DMX	Calhoun	4 hr
Jun 23, 11:56 PM CDT	Severe Thunderstorm Warning	DMX	Butler	34 min
Jun 24, 12:34 AM CDT	Flash Flood Warning	DMX	Hamilton, Webster	4 hr
Jun 24, 2:35 AM CDT	Flash Flood Warning	DMX	Sac	4 hr
Jun 24, 2:50 AM CDT	Flash Flood Warning	DMX	Crawford	4 hr

Nearby

Severe Thunderstorm Warnings in Iowa, 1998 Every severe thunderstorm warning in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.