Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 377

April 4, 200331 counties in Illinois; 29 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2003, 3:10 PM CST for 31 counties in Illinois; 29 counties in Indiana. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 4, 2003, 3:10 PM CST (21:10 UTC)
Expired
Apr 4, 2003, 5:15 PM CST
In force
2 hr
Issued by
the Storm Prediction Center
All 60 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Greene County, IL, Iroquois County, IL, Jasper County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Vermilion County, IL, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clay County, IN, Clinton County, IN, Delaware County, IN, Fountain County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Madison County, IN, Marion County, IN, Miami County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, White County, IN

The radar

The Lincoln radar (KILX), 94 km from the middle of the area, began a volume at 21:13 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, 9.2 hours before the alert went out and 38 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 2003-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 60 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 2003-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 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
60 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
622 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
91 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

715 
ACUS11 KWNS 042110
SWOMCD
SPC MCD 042110 
INZ000-ILZ000-MOZ000-042315-

MESOSCALE DISCUSSION 0377
NWS STORM PREDICTION CENTER NORMAN OK
0310 PM CST FRI APR 04 2003

AREAS AFFECTED...ECNTRL MO...CNTRL/SRN IL AND CNTRL IND

CONCERNING...TORNADO WATCH 85...86...

VALID 042110Z - 042315Z

...TORNADO THREAT INCREASING ACROSS THE AREA...



SEVERAL DISCRETE SUPERCELLS CONTINUE TO MOVE ENEWD ACROSS THE MS
RVR NEAR STL INTO CNTRL/SRN IL WHILE POTENTIALLY TORNADIC
SUPERCELLS MOVE ACROSS CNTRL IL.  LATEST MESOANALYSIS HAS SHOWN A
TREND IN BACKING AND INCREASING LOW LEVEL FLOW ACROSS CNTRL IL
INVOF OF A WARM FRONT AND RECENT VWP FROM ILX SHOWS A RATHER LONG
AND LOOPY HODOGRAPH WITH LOW LEVEL SRH HAVING INCREASED TO ABOVE
160 M2/S2.  AIR MASS DOWNSTREAM CONTINUES TO BE SUPPORTIVE OF
TSTMS...AND GIVEN INCREASINGLY FAVORABLE KINEMATICS...SUPERCELLS
WITH VERY LARGE HAIL...TORNADOES AND DAMAGING WIND GUSTS WILL
CONTINUE TO DEVELOP.  THESE CELLS WILL BECOME ESPECIALLY CAPABLE
OF TORNADOES AS THEY MOVE NWD INTO BAROCLINIC ZONE SITUATED FROM
CMI-DNV-MIE.

..RACY.. 04/04/2003

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

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

39389078 40338990 40798883 40918692 40748531 39998501
39228701 38548995

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 4, 7:23 AM CSTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 55 more97 min
Apr 4, 9:47 AM CSTMesoscale DiscussionSPCClark, Coles, Crawford, Cumberland, Douglas, Edgar and 9 more58 min
Apr 4, 11:10 AM CSTMesoscale DiscussionSPCBond, Calhoun, Cass, Champaign, Christian, Clinton and 24 more95 min
Apr 4, 12:05 PM CSTTornado WatchSPCAdams, Brown, Calhoun, Cass, Greene, Jersey and 10 more5 hr
Apr 4, 1:12 PM CSTMesoscale DiscussionSPCBond, Brown, Calhoun, Cass, Champaign, Christian and 35 more93 min
Apr 4, 1:29 PM CSTMesoscale DiscussionSPCBureau, Cook, DeKalb, DuPage, Grundy, Kane and 8 more91 min
Apr 4, 2:35 PM CSTTornado WatchSPCBond, Champaign, Christian, Clark, Clay, Clinton and 26 more5 hr
Apr 4, 4:25 PM CSTTornado WatchSPCAlexander, Bond, Clay, Clinton, Edwards, Franklin and 24 more6 hr
Apr 4, 5:11 PM CSTMesoscale DiscussionSPCBond, Champaign, Christian, Clark, Clay, Clinton and 24 more2 hr

Nearby

Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Indiana, 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.