Alert archive / Michigan / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 21, NWS Marquette, MI

July 17, 1997Houghton County, Keweenaw County, Michigan

NWS Marquette, MI issued this severe thunderstorm warning at Jul 17, 1997, 2:56 AM EDT for Houghton County, Keweenaw County, Michigan. It was in force for 44 min. 2 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
Jul 17, 1997, 2:56 AM EDT (06:56 UTC)
Expired
Jul 17, 1997, 3:40 AM EDT
In force
44 min
Issued by
NWS Marquette, MI
Area
Whole counties

Counties Houghton County, MI, Keweenaw County, MI

The radar

The Marquette radar (KMQT), 95 km from the middle of the area, began a volume at 06:55 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
Jul 17, 3:15 AM EDTThunderstorm Wind 55Lake Linden, MISeveral trees and power lines downed.
Jul 17, 3:20 AM EDTThunderstorm Wind 55Calumet, MISeveral trees downed up to 12 inches in diameter.

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

Green Bay/Straub, WI (KGRB), launched 00:00Z, 6.9 hours before the alert went out and 297 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, Green Bay/Straub, WI at 00:00Z on 1997-07-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 536 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 00:00Z on 1997-07-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.19395878Sfc1 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
536 J/kg
Mixed-layer CIN
-290 J/kg
Mixed-layer LCL
2104 m above ground
0-6 km bulk shear
72 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
171 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMQT 170655 RRA
SVRMQT
MIC061-083-170740-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MARQUETTE MI
256 AM EDT THU JUL 17 1997

* SEVERE THUNDERSTORM WARNING FOR
  KEWEENAW COUNTY - NORTHWESTERN UPPER MICHIGAN
  NORTHERN HOUGHTON COUNTY - NORTHWESTERN UPPER MICHIGAN

* UNTIL 340 AM EDT
 
* SOME LOCATIONS AFFECTED
  HOUGHTON/HANCOCK
  CALUMET
  EAGLE RIVER
  LAKE LINDEN

* AT 253 AM EDT DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM OVER
  LAKE SUPERIOR 15 MILES NORTHWEST AT CALUMET. THE STORM WAS MOVING
  SOUTHEAST AT 50 MPH. LARGE HAIL AND DAMAGING WINDS IN EXCESS OF
  60 MPH ARE LIKELY WITH THIS STORM.

* THE STORM WILL BE NEAR CALUMET AT 305 AM.

STAY *INDOORS AND AWAY FROM WINDOWS. IF YOU ARE CAUGHT OUTSIDE...
SEEK SHELTER IN A STRONG BUILDING.


DERNER

The office that day

Everything else NWS Marquette, MI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 17, 3:51 AM EDTSevere Thunderstorm WarningMQTBaraga59 min
Jul 17, 4:08 AM EDTSevere Thunderstorm WarningMQTMarquette62 min
Jul 17, 5:18 AM EDTSevere Thunderstorm WarningMQTAlger47 min

Nearby

Severe Thunderstorm Warnings in Michigan, 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.