Alert archive / Minnesota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 158, NWS Twin Cities, MN

July 18, 1997Yellow Medicine County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 18, 1997, 4:49 AM CDT for Yellow Medicine County, Minnesota. It was in force for 61 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 18, 1997, 4:49 AM CDT (09:49 UTC)
Expired
Jul 18, 1997, 5:50 AM CDT
In force
61 min
Issued by
NWS Twin Cities, MN
Area
Whole counties

County Yellow Medicine County, MN

The radar

The Sioux Falls radar (KFSD), 143 km from the middle of the area, began a volume at 09:53 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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 9.8 hours before the alert went out and 180 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 1997-07-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2108 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 1997-07-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
2108 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1253 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
-0.2
Supercell composite
-1.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSP 180952 RRA
SVRMSP
MNC173-181050-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
449 AM CDT FRI JUL 18 1997

* SEVERE THUNDERSTORM WARNING FOR
  YELLOW MEDICINE COUNTY - SOUTHWESTERN MINNESOTA

* UNTIL 550 AM CDT
 
* SOME LOCATIONS AFFECTED
    PORTER
    CANBY
    ST. LEO
    HANLEY FALLS

* AT 450 AM DOPPLER RADAR INDICATED A SEVERE STORM WITH LARGE HAIL
  NEAR PORTER OR ABOUT 23 MILES NORTHWEST OF MARSHALL.  THE STORM
  WAS MOVING NORTHEAST AT 25 MPH.

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


MBK

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 5:05 AM CDTSevere Thunderstorm WarningMPXLac qui Parle60 min
Jul 18, 7:53 AM CDTSevere Thunderstorm WarningMPXBlue Earth47 min
Jul 18, 8:03 AM CDTSevere Thunderstorm WarningMPXWaseca32 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.