Alert archive / Minnesota / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 286, NWS Twin Cities, MN

July 20, 1998Blue Earth County, Nicollet County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 20, 1998, 11:35 AM CDT for Blue Earth County, Nicollet County, Minnesota. It was in force for 60 min. 10 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 20, 1998, 11:35 AM CDT (16:35 UTC)
Expired: Jul 20, 1998, 12:35 PM CDT
In force: 60 min
Issued by: NWS Twin Cities, MN
Area: Whole counties

Counties Blue Earth County, MN, Nicollet County, MN

The radar

The Minneapolis radar (KMPX), 87 km from the middle of the area, began a volume at 16:38 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
Jul 20, 11:50 AM CDT	Thunderstorm Wind 80	Courtland, MN	Grain elevator sustained extensive damage. Apartment building garage damaged. Firehall damaged. Trees down. Estimated windspeed
Jul 20, 11:50 AM CDT	Thunderstorm Wind 80	Courtland, MN	Extensive farm damage. Shed destroyed. Roof to chicken house blown off. Estimated windspeed.
Jul 20, 11:50 AM CDT	Thunderstorm Wind 80	Courtland, MN	Garages and barns destroyed. Estimated windspeed.
Jul 20, 11:51 AM CDT	Thunderstorm Wind 75	Courtland, MN	Roof torn off barn. Shed destroyed. Estimated windspeed.
Jul 20, 12:00 PM CDT	Thunderstorm Wind 80	Nicollet, MN	Roof torn off high school gymnasium resulting in water damage to floor. Garage walls blown down at pair of houses in northwestern part of town. High winds affected 100,000 to 115,000 acres across Nicollet county. 50,000 acres of crops severely damaged. Da
Jul 20, 12:00 PM CDT	Thunderstorm Wind 75	Nicollet, MN	Hog barn destroyed. 500 acres of corn flattened.
Jul 20, 12:04 PM CDT	Thunderstorm Wind 80	Nicollet, MN	Shingles off roof. Trees blown down. Estimated windspeed.
Jul 20, 12:05 PM CDT	Thunderstorm Wind 80	Nicollet, MN	Barns and sheds blown down. Estimated windspeed.
Jul 20, 12:05 PM CDT	Thunderstorm Wind 55	Lake Crystal, MN	Trees blown down. Estimated windspeed.
Jul 20, 12:10 PM CDT	Thunderstorm Wind 52	St Peter, MN	Trees blown down. New roof construction destroyed. Several homes and businesses had roof damage. Mobile homes damaged in Summit Park. Windows broken at Gustavus Adolphus College. Stronger wind gusts in surrounding areas.

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 nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 4.6 hours before the alert went out and 85 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2372 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 63 m²/s²
0-3 km storm-relative helicity: 103 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

873 
WUUS1 KMSP 201633 RRA
SVRMSP
MNC013-103-201735-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1135 AM CDT MON JUL 20 1998

THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES/CHANHASSEN HAS
ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN BLUE EARTH COUNTY IN SOUTH CENTRAL MINNESOTA
  NICOLLET COUNTY IN SOUTH CENTRAL MINNESOTA

* UNTIL 1235 PM CDT

* AT 1135 AM CDT...DOPPLER RADAR INDICATED A SEVERE STORM WITH LARGE
  HAIL AND DAMAGING WINDS NEAR SLEEPY EYE OR 8 MILES WEST OF NEW
  ULM.
  THE STORM WAS MOVING EAST AT 40 MPH .

* SOME LOCATIONS AFFECTED
    COURTLAND
    NICOLLET
    CAMBRIA
    JUDSON
    CRAY
    MANKATO

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

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 10:19 AM CDT	Severe Thunderstorm Warning	MPX	Redwood	56 min
Jul 20, 10:51 AM CDT	Severe Thunderstorm Warning	MPX	Brown	64 min
Jul 20, 11:43 AM CDT	Tornado Warning	MPX	Nicollet	32 min
Jul 20, 12:05 PM CDT	Severe Thunderstorm Warning	MPX	Le Sueur	40 min
Jul 20, 12:22 PM CDT	Severe Thunderstorm Warning	MPX	Rice	63 min
Jul 20, 12:51 PM CDT	Severe Thunderstorm Warning	MPX	Goodhue	64 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 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.