Alert archive / Indiana / Mesoscale Discussions in 2003

Mesoscale Discussion 1682

July 7, 20034 counties in Illinois; 50 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Jul 7, 2003, 4:34 PM CDT for 4 counties in Illinois; 50 counties in Indiana. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Jul 7, 2003, 4:34 PM CDT (21:34 UTC)
Expired
Jul 7, 2003, 5:30 PM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 54 counties

Iroquois County, IL, Kankakee County, IL, Vermilion County, IL, Will County, IL, Allen County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Franklin County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Johnson County, IN, Kosciusko County, IN, Lake County, IN, LaPorte County, IN, Madison County, IN, Marion County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Parke County, IN, Porter County, IN, Pulaski County, IN, Putnam County, IN, Randolph County, IN, Rush County, IN, Saint Joseph County, IN, Shelby County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Union County, IN, Vermillion County, IN, Wabash County, IN, Warren County, IN, Wayne County, IN, Wells County, IN, White County, IN, Whitley County, IN

The radar

The Indianapolis radar (KIND), 100 km from the middle of the area, began a volume at 21:37 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

Lincoln, IL (KILX), launched 12:00Z, 9.6 hours before the alert went out and 165 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 2003-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1626 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 2003-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
1626 J/kg
Mixed-layer CIN
-70 J/kg
Mixed-layer LCL
1135 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
113 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.

686 
ACUS11 KWNS 072134
SWOMCD
SPC MCD 072134 
OHZ000-INZ000-ILZ000-072230-

MESOSCALE DISCUSSION 1682
NWS STORM PREDICTION CENTER NORMAN OK
0434 PM CDT MON JUL 07 2003

AREAS AFFECTED...NRN IN / NCNTRL IN / ERN IL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 072134Z - 072230Z

EXPECT A CONTINUATION OF RECENT BACKBUILDING TRENDS FROM PARTS OF
ECNTRL IN WWD INTO PART OF NRN/NCNTRL IN...POSSIBLY BACK INTO
ERN/NERN IL OVER THE NEXT FEW HOURS. A WW ISSUANCE IS POSSIBLE.

RECENT VISIBLE IMAGERY SHOWS BACKBUILDING ACTIVITY BEGINNING TO
INTENSIFY IN ECNTRL/NCNTRL IN AMIDST A VERY UNSTABLE ATMOSPHERE
RECOVERING FROM PREVIOUS MCS FEATURE PRESENTLY IN ERN/SERN OH.
STORMS APPEARS TO BE INITIATING ON RATHER SUBTLE REMNANT OUTFLOW
BOUNDARY ORIENTED FROM THE SSE TO NNW FROM AROUND MUNCIE TO SOUTH OF
THE SOUTH BEND AREA. ANOTHER BOUNDARY IS SEMI DISCERNABLE FROM NEAR
COVINGTON OHIO NWWD TO AROUND LAF IN WRN/NWRN IN WHERE WIDESPREAD
CUMULUS CONTINUE TO ORGANIZE.

STORMS SHOULD CONTINUE TO STRENGTHEN IN THESE AREAS INITIALLY IN THE
VICINITIES OF THESE BOUNDARIES GIVEN A VERY/EXTREMELY UNSTABLE
BOUNDARY LAYER. WITH 500MB FLOW MORE NWLY AND SSWLY SURFACE LAYER
WINDS...0-6KM WIND SHEAR VALUES HAVE INCREASED TO BETWEEN 40-45
KTS...WITH OBJECTIVE ANALYSES INDICATING AROUND 150 SRH VALUES FOR
THESE AREAS. GIVEN THE DEGREE OF INSTABILITY AND INCREASING WIND
SHEAR IN THESE AREAS IT APPEARS AS IF A TORNADO THREAT IS POSSIBLE 
INTO THE EARLY EVENING HOURS. OTHERWISE...A LARGE HAIL AND DAMAGING
WIND THREAT WITH AREAS OF VERY HEAVY RAINFALL ARE LIKELY FOR SOME OF
THESE AREAS AS STORMS WILL CONTINUE EXHIBITING BACKBUILDING
CHARACTERISTICS.

..NADEN.. 07/07/2003

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

ATTN...WFO...ILN...IWX...IND...LOT...ILX...

39548706 39958803 40998816 41398805 41778777 41718626
41138508 40058473 39378497

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 6, 8:46 PM CDTMesoscale DiscussionSPCBoone, Cook, DeKalb, DuPage, Ford, Grundy and 10 more59 min
Jul 7, 1:25 AM CDTMesoscale DiscussionSPCJo Daviess, Stephenson, Winnebago95 min
Jul 7, 2:40 AM CDTSevere Thunderstorm WatchSPCJo Daviess4 hr
Jul 7, 4:22 AM CDTMesoscale DiscussionSPCJo Daviess, Stephenson83 min
Jul 7, 6:23 AM CDTMesoscale DiscussionSPCBureau, Carroll, DeKalb, Grundy, Henry, Kendall and 9 more97 min
Jul 7, 8:30 AM CDTMesoscale DiscussionSPCChampaign, DeWitt, Douglas, Ford, Grundy, Iroquois and 13 more60 min
Jul 7, 8:45 AM CDTSevere Thunderstorm WatchSPCChampaign, Cook, DeWitt, Ford, Grundy, Iroquois and 6 more4 hr
Jul 7, 10:14 AM CDTMesoscale DiscussionSPCChampaign, DeWitt, Ford, Iroquois, McLean, Piatt and 1 more61 min
Jul 7, 12:14 PM CDTMesoscale DiscussionSPCBond, Brown, Cass, Champaign, Christian, Clark and 42 more61 min
Jul 7, 2:35 PM CDTMesoscale DiscussionSPCBoone, Jo Daviess, McHenry, Stephenson, Winnebago115 min
Jul 7, 3:35 PM CDTSevere Thunderstorm WatchSPCRock Island5 hr
Jul 6, 11:10 PM CDTSevere Thunderstorm WatchSPCBartholomew, Boone, Brown, Clinton, Dearborn, Decatur and 21 more3 hr
Jul 6, 11:51 PM CDTMesoscale DiscussionSPCBartholomew, Boone, Brown, Clinton, Dearborn, Decatur and 21 more114 min
Jul 7, 11:30 AM CDTSevere Thunderstorm WatchSPCFayette, Henry, Jay, Randolph, Rush, Union and 1 more6 hr
Jul 7, 5:30 PM CDTTornado WatchSPCAdams, Allen, Blackford, Carroll, Cass, Clinton and 28 more6 hr

Nearby

Mesoscale Discussions in Indiana, 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.