Alert archive / Minnesota / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 227, NWS Twin Cities, MN

September 18, 1997Mille Lacs County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Sep 18, 1997, 5:53 PM CDT for Mille Lacs County, Minnesota. It was in force for 67 min. 6 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: Sep 18, 1997, 5:53 PM CDT (22:53 UTC)
Expired: Sep 18, 1997, 7:00 PM CDT
In force: 67 min
Issued by: NWS Twin Cities, MN
Area: Whole counties

County Mille Lacs County, MN

What was reported inside it

Time	Report	Where	Remark
Sep 18, 6:22 PM CDT	Hail 1	Onamia, MN
Sep 18, 6:25 PM CDT	Tornado F3	Onamia, MN	Several buildings destroyed and numerous other buildings damaged. Hundreds of trees down. A number of cattle killed in barn collapse. Damage estimate included in entry for Morrison county. Total path length from 1 NE of Lastup to Onamia was 17 miles.
Sep 18, 6:48 PM CDT	Tornado F1	Wahkon, MN
Sep 18, 6:48 PM CDT	Hail 2	Wahkon, MN
Sep 18, 6:50 PM CDT	Hail 1.75	Wahkon, MN
Sep 18, 7:10 PM CDT	Hail 1.75	Isle, MN

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 watch it was issued in

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

Issued	Product	Office	Lasted
Sep 18, 5:30 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.9 hours before the alert went out and 121 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: 228 J/kg
Mixed-layer CIN: -404 J/kg
Mixed-layer LCL: 1391 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 477 m²/s²
0-3 km storm-relative helicity: 490 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.3

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMSP 182254 RRA
SVRMSP
MNC095-190000-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
553 PM CDT THU SEP 18 1997


* SEVERE THUNDERSTORM WARNING FOR
  NORTHERN MILLE LACS COUNTY - CENTRAL MINNESOTA

* UNTIL 700 PM CDT

* SOME LOCATIONS AFFECTED
    SOUTHERN MILLE LACS LAKE
    MILLE LACS LAKE INDIAN RESERVATION
    ONAMIA
    WAHKON/ISLE

* AT 552 PM CDT DOPPLER RADAR INDICATED A SEVERE STORM WITH LARGE
  HAIL AND DAMAGING WINDS FROM 10 MILES NORTH OF LITTLE FALLS TO
  20 MILES NORTHEAST OF  LITTLE FALLS.  THE STORMS WERE MOVING
  EAST AT 30 MPH.

THIS IS A DANGEROUS STORM.  STAY INDOORS AWAY FROM WINDOWS.
A TORNADO WATCH IS IN EFFELCT.  SEVERE THUNDERSTORMS CAN PRODUCE
TORNADOES.

TDK

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Local storm report, Sep 18, 5:45 PM CDT, 8 minutes before

PRELIMINARY LOCAL STORM REPORT...ADDITION INFORMATION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MINNESOTA
545 PM CDT THU SEP 18 1997

TIME(CDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0525 PM    CAMP RIPLEY JCT           MN   TORNADO  F0
09/18/97   MORRISON                       PATH 1/2 MILE  100 YARD
                                                          WIDE
0615 PM    1NE LASTRUP               MN   TORNADO  STRONG F3
09/18/97   MORRISON                       *** 2 INJ ***
                                          SEVERAL BUILDINGS DAMAGED
                                          TORNADO TRACK EAST FOR
                                          ABOUT 17 MILES.  1/4 TO 1/3
                                          WIDE.

09/18/97   4NNE ROYALTON             MN   TORNADO  STRONG F2
           MORRISON                       PATH LENGTH 8 MI 300 YARD
                                          WIDE
0648 PM    WAHKON                    MN   2.20 INCH HAIL
09/18/97   MILLE LACS

0620 PM    5N HILLMAN                MN   3.00 INCH HAIL
09/18/97   MORRISON

THESE REPORTS WERE REPORTED BY NATIONAL WEATHER SERVICE FIELD
REPRESENTATIVE THIS EVENING AFTER REVIEWING STORM DAMAGE.  THIS
REPORT IS NOT COMPLETE. WE HOPE TO HAVE ADDITIONAL INFORMATION ON
SURVEY DAMAGE FROM THURSDAY EVENING STORMS.

JVM

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 18, 5:13 PM CDT	Severe Thunderstorm Warning	MPX	Morrison	32 min
Sep 18, 5:24 PM CDT	Tornado Warning	MPX	Morrison	51 min
Sep 18, 6:04 PM CDT	Tornado Warning	MPX	Douglas, Todd	26 min
Sep 18, 6:08 PM CDT	Tornado Warning	MPX	Mille Lacs, Morrison	52 min
Sep 18, 6:24 PM CDT	Severe Thunderstorm Warning	MPX	Kanabec	66 min
Sep 18, 6:30 PM CDT	Tornado Warning	MPX	Kanabec	60 min
Sep 18, 6:34 PM CDT	Tornado Warning	MPX	Morrison, Todd	41 min
Sep 18, 6:57 PM CDT	Tornado Warning	MPX	Mille Lacs	33 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 1997 Every 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.