Alert archive / Indiana / Mesoscale Discussions in 2004

Mesoscale Discussion 2129

August 27, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2004, 6:33 AM CDT for 4 states. It was in force for 27 min.

The area

The outline as issued.

The facts

Issued
Aug 27, 2004, 6:33 AM CDT (11:33 UTC)
Expired
Aug 27, 2004, 7:00 AM CDT
In force
27 min
Issued by
the Storm Prediction Center
All 65 counties

Champaign County, IL, DeWitt County, IL, Ford County, IL, Iroquois County, IL, Mason County, IL, McLean County, IL, Peoria County, IL, Tazewell County, IL, Vermilion County, IL, Woodford County, IL, Allen County, IN, Benton County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Elkhart County, IN, Fountain County, IN, Fulton County, IN, Grant County, IN, Howard County, IN, Huntington County, IN, Kosciusko County, IN, LaGrange County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Noble County, IN, Pulaski County, IN, Steuben County, IN, Tippecanoe County, IN, Tipton County, IN, Wabash County, IN, Warren County, IN, Wells County, IN, White County, IN, Whitley County, IN, Arenac County, MI, Bay County, MI, Branch County, MI, Calhoun County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Hillsdale County, MI, Huron County, MI, Ingham County, MI, Jackson County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI, Defiance County, OH, Fulton County, OH, Paulding County, OH, Williams County, OH

The radar

The Northern Indiana radar (KIWX), 52 km from the middle of the area, began a volume at 11:34 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 11.6 hours before the alert went out and 232 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 00:00Z on 2004-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 636 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 00:00Z on 2004-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 square meters per square second.193958Sfc1 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
636 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
918 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
157 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

897 
ACUS11 KWNS 271135
SWOMCD
SPC MCD 271133 
MIZ000-OHZ000-INZ000-ILZ000-271200-

MESOSCALE DISCUSSION 2129
NWS STORM PREDICTION CENTER NORMAN OK
0633 AM CDT FRI AUG 27 2004

AREAS AFFECTED...NRN IL / NWRN IN / ERN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 790...

VALID 271133Z - 271200Z

STORMS HAVE WEAKENED AND CONTINUE TO MOVE OUT OF WW.  WATCH WILL BE
ALLOWED TO EXPIRE AS SCHEDULED AT 27/12Z.

BROKEN LINE OF STORMS HAS WEAKENED OVER THE PAST HOUR...AND IS NOW
MOVING E OF WW ACROSS ERN LOWER MI / NRN IN.  DESPITE SUFFICIENT
INSTABILITY AND FAVORABLE WIND FIELD...STORMS ARE LIKELY ELEVATED
ABOVE STABLE BOUNDARY LAYER.  THEREFORE...EXPECT ANY REMAINING
SEVERE THREAT TO CONTINUE DIMINISHING THROUGH THE REMAINDER OF THE
MORNING.

..GOSS.. 08/27/2004

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

ATTN...WFO...CLE...DTX...APX...IWX...GRR...IND...LOT...ILX...

44078378 44068284 43078252 41418398 39918629 40098785
40169042 40898969 40688807 41118670 41888545

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 26, 9:13 PM CDTMesoscale DiscussionSPCCarroll, Jo Daviess, Rock Island, Stephenson62 min
Aug 26, 9:45 PM CDTSevere Thunderstorm WatchSPCBoone, Carroll, Henderson, Henry, Jo Daviess, Mercer and 5 more6 hr
Aug 26, 11:53 PM CDTMesoscale DiscussionSPCBureau, Cook, DeKalb, DuPage, Grundy, Kane and 8 more97 min
Aug 27, 1:25 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Cook, DeKalb, DeWitt, DuPage and 25 more6 hr
Aug 27, 1:49 AM CDTMesoscale DiscussionSPCHenderson, Henry, Mercer, Ogle, Rock Island, Whiteside and 1 more56 min
Aug 27, 4:36 AM CDTMesoscale DiscussionSPCCook, DeWitt, Ford, Fulton, Grundy, Hancock and 11 more84 min
Aug 27, 9:24 AM CDTMesoscale DiscussionSPCCalhoun, Greene, Jersey, Macoupin, Madison, Morgan and 2 more96 min
Aug 27, 9:40 AM CDTSevere Thunderstorm WatchSPCBrown, Calhoun, Cass, Greene, Jersey, Macoupin and 7 more5 hr
Aug 27, 1:07 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Greene, Jersey and 6 more113 min
Aug 27, 2:45 PM CDTSevere Thunderstorm WatchSPCCalhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more6 hr
Aug 27, 3:49 PM CDTMesoscale DiscussionSPCCalhoun, Cass, Greene, Jersey, Morgan, Pike and 1 more86 min
Aug 27, 4:10 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Fulton, Hancock, Henderson and 14 more2 hr
Aug 27, 12:10 PM CDTMesoscale DiscussionSPCAdams, Allen, Blackford, Carroll, Cass, DeKalb and 8 more3 hr
Aug 27, 1:39 AM CDTMesoscale DiscussionSPCAntrim, Arenac, Benzie, Cheboygan, Clare, Crawford and 15 more66 min
Aug 27, 12:39 PM CDTMesoscale DiscussionSPCBarry, Bay, Calhoun, Clinton, Eaton, Genesee and 23 more2 hr

Nearby

Mesoscale Discussions in Indiana, 2004Mesoscale Discussions in Michigan, 2004Mesoscale Discussions in Illinois, 2004Every mesoscale discussion in 2004

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.