Alert archive / Michigan / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 41, NWS Gaylord, MI

July 21, 2002Mackinac County, Michigan

NWS Gaylord, MI issued this severe thunderstorm warning at Jul 21, 2002, 7:39 PM EDT for Mackinac County, Michigan. It was in force for 51 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jul 21, 2002, 7:39 PM EDT (23:39 UTC)
Expired: Jul 21, 2002, 8:30 PM EDT
In force: 51 min
Issued by: NWS Gaylord, MI
Area: Counties, with a storm outline in the text

County Mackinac County, MI

The radar

The NCL Michigan radar (KAPX), 138 km from the middle of the area, began a volume at 23:39 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

Time	Report	Where	Remark
Jul 21, 7:55 PM EDT	Thunderstorm Wind 50 E	Curtis, MI	Numerous trees down.

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
Jul 21, 7:25 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Alpena, MI (KAPX), launched 12:00Z, 11.7 hours before the alert went out and 250 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: 2407 J/kg
Mixed-layer CIN: -69 J/kg
Mixed-layer LCL: 821 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 307 m²/s²
0-3 km storm-relative helicity: 327 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 9.1

Open this sounding in Storm Lab

The text

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

595 
WUUS53 KAPX 212339
SVRAPN
MIC097-220030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GAYLORD MI
738 PM EDT SUN JUL 21 2002

THE NATIONAL WEATHER SERVICE IN GAYLORD HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MACKINAC COUNTY IN EASTERN UPPER MICHIGAN

* UNTIL 830 PM EDT

* AT 738 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A LINE OF SEVERE THUNDERSTORMS FROM 9 MILES SOUTHEAST OF GRAND
  MARAIS TO 13 MILES SOUTH OF MANISTIQUE...MOVING EAST AT 50 MPH.

* THE SEVERE THUNDERSTORMS WILL REACH...
  CURTIS AROUND 755 PM EDT
  GOULD CITY AROUND 800 PM EDT
  ENGADINE AROUND 805 PM EDT
  NAUBINWAY AROUND 815 PM EDT
  GARNET AROUND 820 PM EDT
  EPOUFETTE AROUND 825 PM EDT

REMAIN INDOORS AND AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED. THIS
STORM IS CAPABLE OF PRODUCING WIND GUSTS BETWEEN 60 AND 80 MPH ALONG
WITH DIME SIZED OR LARGER HAIL. WINDS THIS HIGH CAN DOWN TREES AND
POWER LINES.

LAT...LON 4615 8481 4591 8489 4602 8502 4604 8520
          4609 8532 4610 8552 4597 8566 4598 8585
          4624 8585 4624 8512 4615 8511

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 6:00 AM EDT	Special Marine Warning	APX		90 min
Jul 21, 6:00 AM EDT	Special Marine Warning	APX		90 min
Jul 21, 6:00 AM EDT	Special Marine Warning	APX		90 min
Jul 21, 6:29 AM EDT	Severe Thunderstorm Warning	APX	Antrim, Charlevoix, Leelanau	31 min
Jul 21, 7:54 AM EDT	Severe Thunderstorm Warning	APX	Kalkaska	51 min
Jul 21, 8:55 AM EDT	Special Marine Warning	APX		65 min
Jul 21, 8:55 AM EDT	Special Marine Warning	APX		65 min
Jul 21, 12:58 PM EDT	Special Marine Warning	APX		22 min
Jul 21, 3:11 PM EDT	Severe Thunderstorm Warning	APX	Alpena	34 min
Jul 21, 7:33 PM EDT	Special Marine Warning	APX		87 min
Jul 21, 7:33 PM EDT	Special Marine Warning	APX		87 min

Nearby

Severe Thunderstorm Warnings in Michigan, 2002 Every severe thunderstorm warning in 2002

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.