Alert archive / Minnesota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 14, NWS Twin Cities, MN

June 20, 1997Hennepin County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jun 20, 1997, 3:55 PM CDT for Hennepin County, Minnesota. It was in force for 35 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
Jun 20, 1997, 3:55 PM CDT (20:55 UTC)
Expired
Jun 20, 1997, 4:30 PM CDT
In force
35 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Hennepin County, MN

The radar

The Minneapolis radar (KMPX), 19 km from the middle of the area, began a volume at 20:55 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

TimeReportWhereRemark
Jun 20, 4:11 PM CDTThunderstorm Wind 50Wayzata, MNLarge tree branches down. Estimated windspeed.

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, 8.9 hours before the alert went out and 20 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-pSkew-T log-p diagram, Minneapolis, MN at 12:00Z on 1997-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 286 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 12:00Z on 1997-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
286 J/kg
Mixed-layer CIN
-231 J/kg
Mixed-layer LCL
1136 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
144 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSP 202056 RRA
SVRMSP
MNC053-202130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
355 PM CDT FRI JUN 20 1997

* SEVERE THUNDERSTORM WARNING FOR
  HENNEPIN COUNTY - EAST CENTRAL MINNESOTA

* UNTIL 430 PM CDT
 
* SOME LOCATIONS AFFECTED
    MOUND
    LAKE MINNETONKA
    EXCELSIOR
    DEEPHAVEN

* AT 352 PM...CDT DOPPLER RADAR INDICATED A SEVERE STORM WITH LARGE
  HAIL AND DAMAGING WINDS JU|ST WEST OF LAKE MINNETONKA...OR ABOUT
  20 MILES WEST OF MINNEAPOLIS.  THE STORM WAS MOVING EAST AT 30
  MPH.


MILLER

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 19, 11:11 PM CDTSevere Thunderstorm WarningMPXStevens, Swift49 min
Jun 19, 11:45 PM CDTSevere Thunderstorm WarningMPXPope45 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1997Every severe thunderstorm warning 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.