Alert archive / Wisconsin / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 157, NWS Twin Cities, MN

July 17, 1997Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 17, 1997, 2:55 AM CDT for Saint Croix County, Wisconsin. It was in force for 65 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 17, 1997, 2:55 AM CDT (07:55 UTC)
Expired
Jul 17, 1997, 4:00 AM CDT
In force
65 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 90 km from the middle of the area, began a volume at 07:58 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.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 17, 1:30 AM CDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 7.9 hours before the alert went out and 93 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 00:00Z on 1997-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2132 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 00:00Z on 1997-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 square meters per square second.193958Sfc1 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
2132 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1981 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
127 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 170759 RRA
SVRMSP
MNC037-049-WIC093-109-170900-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
255 AM CDT THU JUL 17 1997

* SEVERE THUNDERSTORM WARNING FOR
  DAKOTA COUNTY - EAST CENTRAL MINNESOTA
  GOODHUE COUNTY - SOUTHEASTERN MINNESOTA
  PIERCE COUNTY - WEST CENTRAL WISCONSIN
  ST CROIX COUNTY - WEST CENTRAL WISCONSIN

* UNTIL 400 AM CDT
 
* SOME LOCATIONS AFFECTED
    HASTINGS
    RIVER FALLS
    RED WING
    HUDSON

* AT 255 AM CDT DOPPLER RADAR INDICATED SEVERE STORMS JUST EAST OF
  ELKO...OR ABOUT 25 MILES SOUTH OF MINNEAPOLIS.  THE STORM WAS
  MOVING EAST AT 30 MPH.  OTHER STORMS WERE ON THE EAST SIDE OF
  ST PAUL AND bEXTENDED TOWARD FARMINGTON.  70 MPH WINDS WERE
  REPORTED IN FARMINGTON AT 253 AM.

THESE ARE DANGEROUS STORMS.  STAY INDOORS AWAY FROM WINDOWS.


TDK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 16, 11:33 PM CDTSevere Thunderstorm WarningMPXPierce57 min
Jul 17, 12:23 AM CDTSevere Thunderstorm WarningMPXPepin, Pierce67 min
Jul 17, 2:55 AM CDTSevere Thunderstorm WarningMPXPierce65 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.