Alert archive / Iowa / Tornado Warnings in 1997

Tornado Warning 4, NWS La Crosse, WI

July 1, 1997Allamakee County, Winneshiek County, Iowa

NWS La Crosse, WI issued this tornado warning at Jul 1, 1997, 9:24 PM CDT for Allamakee County, Winneshiek County, Iowa. It was in force for 31 min. 4 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: Jul 1, 1997, 9:24 PM CDT (02:24 UTC)
Expired: Jul 1, 1997, 9:55 PM CDT
In force: 31 min
Issued by: NWS La Crosse, WI
Area: Whole counties

Counties Allamakee County, IA, Winneshiek County, IA

The radar

The La Crosse radar (KARX), 68 km from the middle of the area, began a volume at 02:25 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
Jul 1, 9:40 PM CDT	Hail 1.75	Decorah, IA
Jul 1, 9:45 PM CDT	Hail 1.75	Hanover, IA
Jul 1, 9:55 PM CDT	Hail 1.75	Hanover, IA
Jul 1, 10:00 PM CDT	Thunderstorm Wind 55	Waukon, 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
Jul 1, 8:45 PM CDT	Tornado Watch	SPC	5 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 2.4 hours before the alert went out and 207 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: 1089 J/kg
Mixed-layer CIN: -144 J/kg
Mixed-layer LCL: 1458 m above ground
0-6 km bulk shear: 51 kt
0-1 km storm-relative helicity: 40 m²/s²
0-3 km storm-relative helicity: 236 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KLSE 020225 RRA
TORLSE
IAC005-191-020255-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE LA CROSSE WI
924 PM CDT TUE JUL 1 1997

* TORNADO WARNING FOR
    NORTHERN WINNESHIEK COUNTY - NORTHEASTERN IOWA
    NORTHERN ALLAMAKEE COUNTY - NORTHEASTERN IOWA

* UNTIL 955 PM CDT
 
* SOME LOCATIONS AFFECTED
    BURR OAK
    DECORAH
    HIGHLANDVILLE
    LOCUST

* AT 923 PM NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO 5 MILES NORTH OF DECORAH. THE STORM WAS MOVING NORTHEAST
  AT 15 MPH.

* THE STORM WILL BE NEAR LOCUST BY 930 AND NEAR HIGHLANDVILLE BY
  935 PM..

THIS REPLACES THE PRIOR WARNING ISSUED FOR WINNESHIEK COUNTY

IF YOU ARE NEAR THIS DANGEROUS STORM...TAKE COVER IMMEDIATELY IN
THE LOWEST FLOOR AND INNER MOST ROOM OF A BUILDING.

KING

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 1, 8:56 PM CDT	Severe Thunderstorm Warning	ARX	Winneshiek	64 min
Jul 1, 9:53 PM CDT	Tornado Warning	ARX	Allamakee	37 min
Jul 1, 10:29 PM CDT	Tornado Warning	ARX	Allamakee	31 min
Jul 1, 11:03 PM CDT	Severe Thunderstorm Warning	ARX	Clayton	57 min
Jul 1, 11:25 PM CDT	Tornado Warning	ARX	Clayton	45 min

Nearby

Tornado Warnings in Iowa, 1997 Every tornado warning in 1997 Tornadoes in 1997

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.