Alert archive / Michigan / Mesoscale Discussions in 2007

Mesoscale Discussion 1920

August 29, 20078 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Aug 29, 2007, 7:28 PM EDT for 8 counties in Michigan. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Aug 29, 2007, 7:28 PM EDT (23:28 UTC)
Expired
Aug 29, 2007, 9:00 PM EDT
In force
92 min
Issued by
the Storm Prediction Center

Counties Lapeer County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saint Clair County, MI, Sanilac County, MI, Washtenaw County, MI, Wayne County, MI

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 11.5 hours before the alert went out and 14 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, Detroit, MI at 12:00Z on 2007-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 227 joules per kilogram.LCLLFCEL10008507005003002001001 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, Detroit, MI at 12:00Z on 2007-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 square meters per square second.1939Sfc1 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
227 J/kg
Mixed-layer CIN
-187 J/kg
Mixed-layer LCL
1427 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 292328
SWOMCD
SPC MCD 292328 
MIZ000-300100-

MESOSCALE DISCUSSION 1920
NWS STORM PREDICTION CENTER NORMAN OK
0628 PM CDT WED AUG 29 2007

AREAS AFFECTED...SERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 662...

VALID 292328Z - 300100Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 662
CONTINUES.

SEVERE THREAT SLOWLY DIMINISHING ACROSS LOWER MI.

CLUSTER OF RELATIVELY FAST-MOVING STORMS CONTINUES CROSSING SERN
LOWER MI...INVOF COLD FRONT APPROACHING SRN ONTARIO/LK ERIE.  GIVEN
THE COMBINATION OF A LOSS OF DAYTIME HEATING/DESTABILIZATION AND THE
EWD PROGRESSION OF THE FRONT...EXPECT SEVERE THREAT TO END ACROSS WW
AREA AT OR BEFORE THE SCHEDULED 30/01Z EXPIRATION OF WW #662.

..GOSS.. 08/29/2007

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...DTX...

42688390 43568259 43028231 41718341 42028393

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 29, 2:23 PM EDTMesoscale DiscussionSPCBarry, Bay, Branch, Calhoun, Cass, Clinton and 21 more67 min
Aug 29, 3:02 PM EDTSevere Thunderstorm WatchSPCBarry, Calhoun, Clinton, Eaton, Genesee, Huron and 17 more5 hr

Nearby

Mesoscale Discussions in Michigan, 2007Every mesoscale discussion in 2007

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.