Alert archive / Iowa / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 119, NWS Des Moines, IA

May 23, 1998Hamilton County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 23, 1998, 7:03 PM CDT for Hamilton County, Iowa. It was in force for 32 min. 1 report 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: May 23, 1998, 7:03 PM CDT (00:03 UTC)
Expired: May 23, 1998, 7:35 PM CDT
In force: 32 min
Issued by: NWS Des Moines, IA
Area: Whole counties

County Hamilton County, IA

The radar

The Des Moines radar (KDMX), 73 km from the middle of the area, began a volume at 00:08 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
May 23, 7:15 PM CDT	Hail 0.75	Stanhope, 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
May 23, 6:30 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 0.1 hours before the alert went out and 250 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: 2 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 542 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 87 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

122 
WUUS1 KDSM 240004 RRA
SVRDSM
IAC079-240035-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
703 PM CDT SAT MAY 23 1998

THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A

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

* UNTIL 735 PM CDT

* AT 659 PM CDT... DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 27
  MILES EAST SOUTHEAST OF FORT DODGE OR 10 MILES SOUTHWEST OF
  WILLIAMS MOVING NORTHEAST AT 25 MPH.

* THIS STORM CAN BE EXPECTED NEAR WILLIAMS BY 712 PM CDT

THIS IS A DANGEROUS STORM...STAY INDOORS AWAY FROM WINDOWS.

BS

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Local storm report, May 23, 4:36 PM CDT, 2 hours 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
436 PM CDT SAT MAY 23 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0358 PM    SHELL ROCK                IA   3 INCH HAIL
05/23/98   BUTLER

0402 PM    PARKERSBURG               IA   1.75 INCH HAIL
05/23/98   BUTLER                         REPORTED BY BUTLER COUNTY
                                          SHERIFF

Local storm report, May 23, 4:36 PM CDT, 2 hours 27 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DES MOINES IA
436 PM CDT SAT MAY 23 1998

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0358 PM    SHELL ROCK                IA   3 INCH HAIL
05/23/98   BUTLER

0402 PM    PARKERSBURG               IA   1.75 INCH HAIL
05/23/98   BUTLER                         REPORTED BY BUTLER COUNTY
                                          SHERIFF

Special weather statement, May 23, 5:49 PM CDT, 1 hour 14 minutes before

IAZ004>007-015>017-023>028-033>039-044>050-057>062-070>075-081>086-
092>097-241100-

CENTRAL IOWA THUNDERSTORM OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
549 PM CDT SAT MAY 23 1998

HAZARD--A LINE OF THUNDERSTORMS WITH HEAVY RAIN AND HAIL.  WIDESPREAD
SEVERE WEATHER IS NOT ANTICIPATED ALTHOUGH SOME STORMS COULD PRODUCE
HAIL TO ONE INCH.

AREA OF CONCERN--ALL OF CENTRAL IOWA.

TIMING DETAILS--FROM 6 PM TIL MIDNIGHT AND AGAIN TOWARDS MORNING.

METEOROLOGICAL COMMENTS--THUNDERSTORMS ARE DEVELOPING ACROSS WESTERN AND
NORTHERN IOWA ALONG OLD OUTFLOW BOUNDARIES AND AHEAD OF A TROUGH OF LOW
PRESSURE OVER NEBRASKA AND THE DAKOTAS.  THESE STORMS HAVE THE POTENTIAL
FOR HEAVY RAIN AND HAIL.  STORMS ARE ALSO BREAKING OUT ALONG A WARM
FRONT OVER CENTRAL MISSOURI AND THIS MAY SAVE IOWA FROM A WIDESPREAD
SEVERE WEATHER EVENT OVER IOWA.  HOWEVER...A FEW STORMS COULD PRODUCE
HAIL TO ONE INCH.  THE BIGGER THREAT WITH THESE STORMS WILL BE HEAVY
RAIN LEADING TO FLASH FLOODING OF ALREADY HIGH RIVERS.

AFTER MIDNIGHT...THE WARM FRONT OVER CENTRAL MISSOURI WILL BUCKLE AND
850 MB FLOW WILL INCREASE.  THE THETA-E RIDGE PUSHES INTO SOUTH CENTRAL
AND SOUTHEASTERN IOWA AND THIS WILL PRIME THE ENVIRONMENT FOR A POSSIBLE
MESOSCALE CONVECTIVE COMPLEX OF STORMS.  IF THIS DOES OCCUR IT WILL
AFFECT MAINLY THE SOUTHERN TWO TIERS OF COUNTIES OVER IOWA FROM ABOUT
CHARITON IOWA EASTWARD.

PRECAUTIONS -SPOTTER ACTIVATION MAY BE REQUIRED THIS EVENING OVER
WESTERN AND CENTRAL IOWA THIS EVENING AND OVER FAR SOUTHERN IOWA AFTER 3
AM.

FAB

The office that day

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

Issued	Product	Office	Counties	Lasted
May 23, 7:26 PM CDT	Severe Thunderstorm Warning	DMX	Webster	34 min
May 23, 7:31 PM CDT	Severe Thunderstorm Warning	DMX	Wapello	34 min
May 23, 8:19 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Monroe	31 min
May 23, 8:58 PM CDT	Severe Thunderstorm Warning	DMX	Davis	47 min
May 23, 8:59 PM CDT	Severe Thunderstorm Warning	DMX	Davis	46 min
May 23, 9:12 PM CDT	Severe Thunderstorm Warning	DMX	Wapello	33 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.