Alert archive / Indiana / Mesoscale Discussions in 2004

Mesoscale Discussion 1749

July 21, 20044 states

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2004, 10:18 AM CDT for 4 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Jul 21, 2004, 10:18 AM CDT (15:18 UTC)
Expired
Jul 21, 2004, 11:45 AM CDT
In force
87 min
Issued by
the Storm Prediction Center
All 82 counties

Bureau County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Livingston County, IL, Marshall County, IL, Ogle County, IL, Putnam County, IL, Stark County, IL, Will County, IL, Woodford County, IL, Adams County, IN, Allen County, IN, Benton County, IN, Blackford County, IN, Carroll County, IN, Cass County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Grant County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Miami County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, White County, IN, Whitley County, IN, Allegan County, MI, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Livingston County, MI, Monroe County, MI, Oakland County, MI, Saint Joseph County, MI, Shiawassee County, MI, Van Buren County, MI, Washtenaw County, MI, Wayne County, MI, Defiance County, OH, Fulton County, OH, Henry County, OH, Lucas County, OH, Mercer County, OH, Paulding County, OH, Putnam County, OH, Van Wert County, OH, Williams County, OH, Wood County, OH

The radar

The Northern Indiana radar (KIWX), 82 km from the middle of the area, began a volume at 15:18 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

Lincoln, IL (KILX), launched 12:00Z, 3.3 hours before the alert went out and 235 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, Lincoln, IL at 12:00Z on 2004-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1988 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, Lincoln, IL at 12:00Z on 2004-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
1988 J/kg
Mixed-layer CIN
-181 J/kg
Mixed-layer LCL
825 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
158 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.

707 
ACUS11 KWNS 211518
SWOMCD
SPC MCD 211518 
OHZ000-MIZ000-INZ000-ILZ000-211645-

MESOSCALE DISCUSSION 1749
NWS STORM PREDICTION CENTER NORMAN OK
1018 AM CDT WED JUL 21 2004

AREAS AFFECTED...NERN/ECNTRL IL...NRN THIRD OF IND...NWRN OH AND SRN
LOWER MI

CONCERNING...OUTLOOK UPGRADE 

VALID 211518Z - 211645Z

PARTS OF NERN/ECNTRL IL...THE NRN THIRD OF IND...NWRN OH AND SRN
LOWER MI WILL BE UPGRADED TO A MODERATE RISK ON THE 1630Z DAY 1
UPDATE.  18Z SOUNDINGS HAVE BEEN REQUESTED AT ILX/APX/DTX.  

WELL-DEFINED MCV CONTINUES TO MOVE ACROSS SRN IA AND PROFILERS/VWP
SHOW 30-40 KT MIDLEVEL FLOW ASSOCIATED WITH THE FEATURE.  TSTMS HAVE
ALREADY DEVELOPED ACROSS PARTS OF CNTRL/SRN IA AND NRN IL AND WILL
LIKELY INCREASE AS BOUNDARY LAYER HEATING CONTINUES.  THESE TSTMS
WILL BE EMBEDDED IN INCREASING WLY FLOW REGIME AS THE MCV TRACKS EWD
THIS AFTERNOON.  THUS...THERE WILL BE A POTENTIAL FOR ONE OR MORE
BOW ECHOES TO EVOLVE ACROSS THE CNTRL GREAT LAKES AND UPPER MIDWEST.
 HIGHEST WIND DAMAGE POTENTIAL...WITH SOME GUSTS EXCEEDING 70
KTS...WILL BE ACROSS THE MODERATE RISK AREA.

..RACY.. 07/21/2004

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

ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...LOT...ILX...DVN...

42038970 43088445 42568305 41538319 40508444 40348846
41048991

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 7:53 AM CDTMesoscale DiscussionSPCBoone, DuPage, Kane, Lake, McHenry, Stephenson and 1 more2 hr
Jul 21, 9:03 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Champaign, Cook, DeKalb and 37 more117 min
Jul 21, 9:35 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 26 more5 hr
Jul 21, 1:01 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 25 more89 min
Jul 21, 2:35 PM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Cook, DeKalb, DeWitt, DuPage and 20 more6 hr
Jul 21, 5:09 PM CDTMesoscale DiscussionSPCBureau, DeWitt, Ford, Grundy, Iroquois, Kankakee and 13 more36 min
Jul 21, 6:20 PM CDTMesoscale DiscussionSPCClark, Coles, Edgar, Vermilion25 min
Jul 21, 6:35 PM CDTSevere Thunderstorm WatchSPCAdams, Allen, Benton, Blackford, Boone, Carroll and 30 more5 hr
Jul 21, 11:10 AM CDTMesoscale DiscussionSPCAlpena, Antrim, Arenac, Bay, Benzie, Cheboygan and 24 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.