Alert archive / Indiana / Mesoscale Discussions in 2003

Mesoscale Discussion 1621

July 5, 20034 states

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2003, 5:43 AM CDT for 4 states. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Jul 5, 2003, 5:43 AM CDT (10:43 UTC)
Expired
Jul 5, 2003, 7:15 AM CDT
In force
92 min
Issued by
the Storm Prediction Center
All 40 counties

Cook County, IL, Kankakee County, IL, Lake County, IL, Will County, IL, Allen County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall 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, Whitley County, IN, Allegan County, MI, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Saint Joseph County, MI, Van Buren County, MI, Defiance County, OH, Paulding County, OH, Williams County, OH

The radar

The Northern Indiana radar (KIWX), 49 km from the middle of the area, began a volume at 10:45 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, 10.7 hours before the alert went out and 253 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 2003-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 604 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Detroit, MI at 00:00Z on 2003-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 50 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
604 J/kg
Mixed-layer CIN
-123 J/kg
Mixed-layer LCL
1326 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
50 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

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

458 
ACUS11 KWNS 051044
SWOMCD
SPC MCD 051043 
MIZ000-OHZ000-INZ000-ILZ000-WIZ000-051215-

MESOSCALE DISCUSSION 1621
NWS STORM PREDICTION CENTER NORMAN OK
0543 AM CDT SAT JUL 05 2003

AREAS AFFECTED...NE IL/S LOWER MI/N IND/NW OH

CONCERNING...SEVERE THUNDERSTORM WATCH 642...

VALID 051043Z - 051215Z

MCS MOVING EWD ACROSS NERN IL WILL CONTINUE TO HAVE A POTENTIAL FOR
DAMAGING WINDS AND/OR ISOLATED LARGE HAIL AS IT TRACKS EWD ACROSS
NRN IND/SRN LOWER MI. A NEW WW WILL BE ISSUED E OF WW 642 SHORTLY.

SEVERE CONVECTIVE CLUSTER WITH EMBEDDED BOW ECHOES IS CURRENTLY JUST
N OF AN AREA OF STRONG INSTABILITY WITH MLCAPE VALUES AROUND 2000
J/KG. A BAND OF STRONG MID-LEVEL WINDS EXISTS ACROSS NRN IL WITH
ABOUT 40 KT AT 500 MB. AS THE MCS INTERACTS WITH THE INSTABILITY AND
SHEAR...A POTENTIAL FOR DAMAGING WINDS AN/OR LARGE HAIL SHOULD
CONTINUE AS IT TRACKS EWD ACROSS NWRN-NCNTRL IND. HOWEVER...THE MCS
IS MOVING INTO DECREASING LOW-LEVEL MOISTURE WITH SFC DEWPOINTS IN
THE MID 60S F. A SHARP INSTABILITY GRADIENT EXISTED E OF THE CLUSTER
BECAUSE OF A LARGE COLD OUTFLOW REGION GENERATED BY CONVECTION OVER
IND. THIS WILL LIKELY CAUSE THE LINE TO WEAKEN AGAIN SOME AS IT
MOVES INTO NERN IND/OH LATER THIS MORNING. HOWEVER...AN ISOLATED
DAMAGING WIND GUST POTENTIAL SHOULD EXIST FOR THE NEXT FEW HOURS.

..BROYLES.. 07/05/2003

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

ATTN...WFO...DTX...IWX...GRR...LOT...MKX...

40788629 41028824 42668784 42838616 42568381 40938440

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 8:58 PM CDTMesoscale DiscussionSPCDuPage, Grundy, Iroquois, Kane, Kankakee, Kendall and 1 more62 min
Jul 4, 10:09 PM CDTMesoscale DiscussionSPCBrown, Cass, Champaign, DeWitt, Douglas, Ford and 20 more2 hr
Jul 4, 10:45 PM CDTMesoscale DiscussionSPCJo Daviess, Rock Island90 min
Jul 4, 11:25 PM CDTSevere Thunderstorm WatchSPCCarroll, Henderson, Henry, Jo Daviess, Knox, Mercer and 6 more7 hr
Jul 5, 2:31 AM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 27 more89 min
Jul 5, 3:40 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Cook, DeKalb, DuPage, Grundy and 11 more4 hr
Jul 5, 12:55 PM CDTMesoscale DiscussionSPCChampaign, Christian, Clark, Coles, Crawford, Cumberland and 14 more3 hr
Jul 5, 4:34 PM CDTMesoscale DiscussionSPCChampaign, Ford, Iroquois, Vermilion56 min
Jul 5, 5:18 PM CDTMesoscale DiscussionSPCCass, DeWitt, Fulton, Hancock, Henderson, Henry and 16 more57 min
Jul 5, 5:55 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, Champaign, Christian, Clark and 36 more6 hr
Jul 5, 6:00 AM CDTSevere Thunderstorm WatchSPCElkhart, LaGrange, LaPorte, Porter, Saint Joseph, Steuben3 hr
Jul 5, 7:12 AM CDTMesoscale DiscussionSPCAdams, Allen, DeKalb, Elkhart, Fulton, Huntington and 10 more93 min
Jul 5, 4:55 PM CDTSevere Thunderstorm WatchSPCBartholomew, Benton, Boone, Brown, Carroll, Clay and 35 more4 hr

Nearby

Mesoscale Discussions in Indiana, 2003Mesoscale Discussions in Michigan, 2003Mesoscale Discussions in Illinois, 2003Every mesoscale discussion in 2003

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.