Alert archive / Michigan / Severe Thunderstorm Watches in 2002

Severe Thunderstorm Watch 116

April 18, 200247 counties in Michigan

The Storm Prediction Center issued this severe thunderstorm watch at Apr 18, 2002, 7:45 PM EDT for 47 counties in Michigan. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Apr 18, 2002, 7:45 PM EDT (23:45 UTC)
Expired
Apr 19, 2002, 1:00 AM EDT
In force
5 hr
Issued by
the Storm Prediction Center
All 47 counties

Allegan County, MI, Antrim County, MI, Arenac County, MI, Barry County, MI, Bay County, MI, Benzie County, MI, Calhoun County, MI, Charlevoix County, MI, Cheboygan County, MI, Clare County, MI, Clinton County, MI, Crawford County, MI, Eaton County, MI, Emmet County, MI, Gladwin County, MI, Grand Traverse County, MI, Gratiot County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Jackson County, MI, Kalamazoo County, MI, Kalkaska County, MI, Kent County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montcalm County, MI, Montmorency County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Ottawa County, MI, Presque Isle County, MI, Roscommon County, MI, Saginaw County, MI, Shiawassee County, MI, Van Buren County, MI, Wexford County, MI

The radar

The Grand Rapids radar (KGRR), 77 km from the middle of the area, began a volume at 23:44 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.

Warnings issued inside it

21 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 18, 8:08 PM EDTSevere Thunderstorm WarningAPXGrand Traverse, Leelanau, Wexford37 min
Apr 18, 8:14 PM EDTSevere Thunderstorm WarningGRRLake, Newaygo61 min
Apr 18, 8:36 PM EDTSevere Thunderstorm WarningAPXAntrim, Kalkaska39 min
Apr 18, 8:44 PM EDTSevere Thunderstorm WarningAPXWexford31 min
Apr 18, 8:47 PM EDTSevere Thunderstorm WarningGRRMuskegon, Oceana58 min
Apr 18, 9:14 PM EDTSevere Thunderstorm WarningAPXMissaukee, Roscommon61 min
Apr 18, 9:19 PM EDTSevere Thunderstorm WarningGRRLake, Newaygo41 min
Apr 18, 9:23 PM EDTSevere Thunderstorm WarningAPXCrawford22 min
Apr 18, 9:44 PM EDTSevere Thunderstorm WarningGRRMecosta, Montcalm46 min
Apr 18, 9:58 PM EDTSevere Thunderstorm WarningAPXOscoda32 min
Apr 18, 10:16 PM EDTSevere Thunderstorm WarningGRRClare, Isabella59 min
Apr 18, 10:27 PM EDTSevere Thunderstorm WarningAPXGladwin, Roscommon48 min
Apr 18, 10:33 PM EDTSevere Thunderstorm WarningDTXMidland57 min
Apr 18, 10:37 PM EDTSevere Thunderstorm WarningGRRMontcalm23 min
Apr 18, 10:40 PM EDTSevere Thunderstorm WarningGRRKent, Ottawa50 min
Apr 18, 10:58 PM EDTSevere Thunderstorm WarningAPXOgemaw32 min
Apr 18, 11:30 PM EDTSevere Thunderstorm WarningDTXMidland60 min
Apr 18, 11:44 PM EDTSevere Thunderstorm WarningGRRBarry, Clinton, Eaton, Gratiot, Ionia61 min
Apr 18, 11:52 PM EDTSevere Thunderstorm WarningGRRLake, Mason, Oceana38 min
Apr 19, 12:31 AM EDTSevere Thunderstorm WarningGRRMecosta, Muskegon, Newaygo, Osceola29 min
Apr 19, 12:48 AM EDTSevere Thunderstorm WarningGRRIngham42 min

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 12:00Z, 11.8 hours before the alert went out and 228 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 12:00Z on 2002-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Green Bay/Straub, WI at 12:00Z on 2002-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 460 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1774 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
460 m²/s²
0-3 km storm-relative helicity
766 m²/s²
Significant tornado parameter
0.0
Supercell composite
4.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 18, 6:00 PM EDTTornado WatchSPCAlger, Baraga, Delta, Dickinson, Iron, Marquette and 1 more5 hr

Nearby

Severe Thunderstorm Watches in Michigan, 2002Every severe thunderstorm watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.