Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 134, NWS Des Moines, IA

May 28, 1998Grundy County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 28, 1998, 6:01 PM CDT for Grundy County, Iowa. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 28, 1998, 6:01 PM CDT (23:01 UTC)
Expired: May 28, 1998, 6:35 PM CDT
In force: 34 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Grundy County, IA

The radar

The Des Moines radar (KDMX), 107 km from the middle of the area, began a volume at 23:02 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 28, 3:00 PM CDT	Severe Thunderstorm Watch	SPC	5 hr
May 28, 4:00 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.0 hours before the alert went out and 208 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: 530 J/kg
Mixed-layer CIN: -213 J/kg
Mixed-layer LCL: 961 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 173 m²/s²
0-3 km storm-relative helicity: 197 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.8

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KDSM 282301 RRA
SVRDSM
IAC075-282335-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
601 PM CDT THU MAY 28 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  GRUNDY COUNTY IN CENTRAL IOWA

* UNTIL 635 PM CDT

* AT 600 PM CDT... LOCAL LAW ENFORCEMENT REPORTED A SEVERE
  THUNDERSTORM 19 MILES WEST SOUTHWEST OF WATERLOO OR 3 MILES
  NORTHWEST OF MORRISON MOVING EAST AT 15 MPH.

* THIS STORM CAN BE EXPECTED NEAR...
   GRUNDY CENTER      BY 605 PM CDT
   MORRISON           BY 606 PM CDT
   DIKE               BY 611 PM CDT
   REINBECK           BY 616 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.

STARK

The office that day

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

Issued	Product	Office	Counties	Lasted
May 28, 3:14 PM CDT	Tornado Warning	DMX	Pocahontas	36 min
May 28, 3:26 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto	34 min
May 28, 3:49 PM CDT	Tornado Warning	DMX	Pocahontas	31 min
May 28, 4:08 PM CDT	Severe Thunderstorm Warning	DMX	Webster	37 min
May 28, 4:10 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt	30 min
May 28, 4:25 PM CDT	Severe Thunderstorm Warning	DMX	Wright	20 min
May 28, 4:28 PM CDT	Severe Thunderstorm Warning	DMX	Hamilton	32 min
May 28, 4:44 PM CDT	Tornado Warning	DMX	Wright	21 min
May 28, 4:59 PM CDT	Severe Thunderstorm Warning	DMX	Hardin	31 min
May 28, 5:26 PM CDT	Severe Thunderstorm Warning	DMX	Hardin	34 min
May 28, 5:56 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Webster	34 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.