Alert archive / Minnesota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 191, NWS Twin Cities, MN

August 4, 1997Sherburne County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 4, 1997, 12:01 AM CDT for Sherburne County, Minnesota. It was in force for 34 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
Aug 4, 1997, 12:01 AM CDT (05:01 UTC)
Expired
Aug 4, 1997, 12:35 AM CDT
In force
34 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Sherburne County, MN

The radar

The Minneapolis radar (KMPX), 68 km from the middle of the area, began a volume at 05:05 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
Aug 4, 12:25 AM CDTHail 1Elk River, MNCrops damaged.

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 00:00Z, 5.0 hours before the alert went out and 67 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 1997-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1028 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 1997-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 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
1028 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
1282 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSP 040503 RRA
SVRMSP
MNC141-040535-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1201 AM CDT MON AUG 4 1997

* SEVERE THUNDERSTORM WARNING FOR
  SHERBURNE COUNTY - CENTRAL MINNESOTA

* UNTIL 1235 AM CDT
 
* SOME LOCATIONS AFFECTED
    SANTIAGO
    ORROCK
    ZIMMERMAN
    BIG LAKE

* AT 1201 AM CDT DOPPLER RADAR INDICATED A SEVERE STORM WITH LARGE
  HAIL NEAR SANTIAGO OR ABOUT 17 MILES EAST OF ST CLOUD.  THE STORM
  WAS MOVING SOUTH AT 35 MPH.

THIS IS A DANGEROUS STORM...WITH LARGE HAIL.  STAY INDOORS AWAY
FROM WINDOWS.

JJ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 9:36 PM CDTSevere Thunderstorm WarningMPXTodd64 min
Aug 3, 9:51 PM CDTSevere Thunderstorm WarningMPXKanabec59 min
Aug 3, 11:22 PM CDTSevere Thunderstorm WarningMPXStearns, Todd63 min
Aug 4, 12:34 AM CDTSevere Thunderstorm WarningMPXHennepin, Wright41 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.