Alert archive / Michigan / Severe Thunderstorm Warnings in 1996

Severe Thunderstorm Warning 48, NWS Grand Rapids, MI

June 21, 1996Isabella County, Michigan

NWS Grand Rapids, MI issued this severe thunderstorm warning at Jun 21, 1996, 9:27 PM EDT for Isabella County, Michigan. It was in force for 48 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: Jun 21, 1996, 9:27 PM EDT (01:27 UTC)
Expired: Jun 21, 1996, 10:15 PM EDT
In force: 48 min
Issued by: NWS Grand Rapids, MI
Area: Whole counties

County Isabella County, MI

The radar

The Grand Rapids radar (KGRR), 100 km from the middle of the area, began a volume at 01:31 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

Detroit, MI (KDTX), launched 00:00Z, 1.5 hours before the alert went out and 154 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: 471 J/kg
Mixed-layer CIN: -70 J/kg
Mixed-layer LCL: 997 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 135 m²/s²
0-3 km storm-relative helicity: 223 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 3.1

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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.

NWS Grand Rapids, MI wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 1:20 PM EDT, 8 hours 7 minutes earlier.

Area forecast discussion, Jun 21, 1:20 PM EDT, 8 hours 7 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
125 PM EDT FRI JUN 21 1996

AFD WILL BE A LITTLE EARLY TODAY...TRYING TO KEEP UP ON SEVERE
WEATHER THREAT. IN THE SHORT TERM THE SFC RUC DATA SHOWS PRESSURE
FALLS, THETA ADVECTION AND MOISTURE CONVERGENCE OVER NRN IL/SRN WI.
CI/AC SHIELD HOLDING TEMPS DOWN A BIT...BUT HOLES ARE DEVELOPING
WEST OF LAKE MI.

12Z RUN INDICATES STRONG 850 MB JET MOVING INTO IL/WI AROUND 18Z.
AGEOSTROPHIC FLOW AROUND THE 250 MB JET PROVIDING SOME UPPER
LEVEL SUPPORT. THESE DYNAMICS ARE PROGGED TO MOVE EWD THROUGH THE
EVENING. 500 MB WINDS ARE RELATIVELY STRONG AND WITH E-W ORIENTATION
OF THE SFC BNDRY...DERECHO EVENT STILL A GOOD POSIBILITY. SFC HEATING
WILL BE KEY. THE MOST FAVORABLE DYNAMICS OCCUR OVER WESTERN MI NEAR
00Z. STRONG SFC MOISTURE CONVERGENCE ALONG WITH UPPER LEVEL DIVERGENCE
AND THE LOW LEVEL JET COMBINE OVER THE AREA. PCGRIDDS OVERLAY OF
CAPE AND HELICITY SHOW THE BEST AREAS FOR SVR WEATHER SHOULD BE
SOUTHWEST LOWER.

SFC COLD FRONT WILL MOVE INTO WRN MI AROUND 06Z. DYNAMICS SHOULD
BE EAST OF FCST AREA ATM. SHOWERS AND THUNDERSTORMS LIKELY FOR
TONIGHT IS A GOOD FORECAST. STORMS WILL DEFINTELY TAPER OFF AFTER
MIDNIGHT. FWC TEMPS LOOK REASONABLE.

GRR TB 068/083 1771
LAN TB 068/082 1771

END/GARNET

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 21, 9:57 PM EDT	Severe Thunderstorm Warning	GRR	Clare	48 min
Jun 21, 10:08 PM EDT	Flash Flood Warning	GRR	Clare, Osceola	3 hr
Jun 21, 10:18 PM EDT	Severe Thunderstorm Warning	GRR	Isabella	27 min
Jun 21, 10:39 PM EDT	Severe Thunderstorm Warning	GRR	Montcalm	51 min
Jun 22, 1:50 AM EDT	Severe Thunderstorm Warning	GRR	Mason	40 min

Nearby

Severe Thunderstorm Warnings in Michigan, 1996 Every severe thunderstorm warning in 1996

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.