Alert archive / Iowa / Tornado Warnings in 1998

Tornado Warning 53, NWS Omaha, NE

June 23, 1998Monona County, Iowa

NWS Omaha, NE issued this tornado warning at Jun 23, 1998, 8:17 PM CDT for Monona County, Iowa. It was in force for 33 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, 8:17 PM CDT (01:17 UTC)
Expired: Jun 23, 1998, 8:50 PM CDT
In force: 33 min
Issued by: NWS Omaha, NE
Area: Whole counties

County Monona County, IA

The radar

The Omaha radar (KOAX), 88 km from the middle of the area, began a volume at 01:18 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, 8:20 PM CDT	Tornado F0	Whiting, IA
Jun 23, 8:25 PM CDT	Thunderstorm Wind 61	Whiting, IA	Power lines downed.

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, 7:15 PM CDT	Tornado Watch	SPC	6 hr
Jun 23, 7:30 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Topeka, KS (KTOP), launched 00:00Z, 1.3 hours before the alert went out and 340 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: 2696 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 1678 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 319 m²/s²
Significant tornado parameter: 0.7
Supercell composite: 13.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KOMA 240117 RRA
TOROMA
IAC133-240150-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
817 PM CDT TUE JUN 23 1998

THE NATIONAL WEATHER SERVICE IN OMAHA HAS ISSUED A

* TORNADO WARNING FOR...
  MONONA COUNTY IN WEST CENTRAL IOWA

* UNTIL 850 PM CDT

* AT 816 PM CDT... NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A DEVELOPING TORNADO 22 MILES SOUTH SOUTHEAST OF SIOUX CITY OR 6
  MILES NORTHWEST OF WHITING MOVING EAST NORTHEAST AT 25 MPH.

* THE TORNADO IS EXPECTED TO BE NEAR...
  WHITING                      AT 825 PM CDT

IF YOU ARE IN THE WARNED AREA...TAKE SHELTER IN A BASEMENT IF ONE
IS AVAILABLE.  OTHERWISE GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLO\OR.  CARS AND MOBILE HOMES SHOULD BE ABANDONED.

MEAD

What forecasters said that day

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

In the hours before

Special weather statement, Jun 23, 5:05 PM CDT, 3 hours 12 minutes before

NEZ011-012-015>018-030>034-042>045-050>053-065>068-078-088>093-
IAZ043-055-056-069-079-080-090-091-241200-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
505 PM CDT TUE JUN 23 1998

...SEVERE WEATHER OUTLOOK FOR EASTERN NEBRASKA AND SOUTHWEST IOWA...

SPOTTER ACTION...
STORM SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT IN EASTERN NEBRASKA
AND SOUTHWEST IOWA.

DISCUSSION...
THERE IS A CHANCE FOR THUNDERSTORMS TONIGHT IN EASTERN NEBRASKA AND
SOUTHWEST IOWA AS VERY MOIST AND UNSTABLE AIR CONTINUES TO MOVE ACROSS
THE REGION AS A WARM FRONT FROM SOUTH CENTRAL NEBRASKA THROUGH NORTHEAST
KANSAS AND NORTH MISSOURI LIFTS NORTH.

DUE TO THE DEGREE OF INSTABILITY AND WIND SHEAR CONSIDERATIONS...SOME
OF THESE STORMS COULD TURN SEVERE WITH LARGE HAIL...DAMAGING WINDS AND
ISOLATED TORNADOES.

IN ADDITION TO THE THREAT OF SEVERE WEATHER...DUE TO THE VERY MOIST
NATURE OF THE ATMOSPHERE...THE THUNDERSTORMS MAY PRODUCE LOCALLY HEAVY
RAINS.

GW

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 23, 7:24 PM CDT	Tornado Warning	OAX	Monona	51 min
Jun 23, 8:57 PM CDT	Severe Thunderstorm Warning	OAX	Monona	48 min
Jun 23, 9:41 PM CDT	Severe Thunderstorm Warning	OAX	Monona	64 min
Jun 23, 10:21 PM CDT	Tornado Warning	OAX	Harrison, Monona	29 min
Jun 23, 11:12 PM CDT	Flash Flood Warning	OAX	Monona	7 hr

Nearby

Tornado Warnings in Iowa, 1998 Every tornado warning in 1998 Tornadoes 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.