Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 2413

September 26, 200323 counties in Illinois; 14 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Sep 26, 2003, 6:59 PM CDT for 23 counties in Illinois; 14 counties in Indiana. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Sep 26, 2003, 6:59 PM CDT (23:59 UTC)
Expired
Sep 26, 2003, 8:30 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
All 37 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Jasper County, IL, Logan County, IL, Macon County, IL, Menard County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Sangamon County, IL, Shelby County, IL, Vermilion County, IL, Boone County, IN, Clay County, IN, Fountain County, IN, Greene County, IN, Hendricks County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Sullivan County, IN, Vermillion County, IN, Vigo County, IN

The radar

The Lincoln radar (KILX), 118 km from the middle of the area, began a volume at 00:03 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, 12.0 hours before the alert went out and 83 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 2003-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2003-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 210 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2018 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
210 m²/s²
0-3 km storm-relative helicity
246 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.

424 
ACUS11 KWNS 262359
SWOMCD
SPC MCD 262359 
INZ000-ILZ000-270130-

MESOSCALE DISCUSSION 2413
NWS STORM PREDICTION CENTER NORMAN OK
0659 PM CDT FRI SEP 26 2003

AREAS AFFECTED...CNTRL AND ERN IL INTO WRN IND

CONCERNING...TORNADO WATCH 930...

VALID 262359Z - 270130Z

THE THREAT OF ISOLATED TORNADOES WILL CONTINUE ACROSS CNTRL AND SRN
PORTIONS OF WW AREA THROUGH 01 OR 02Z.

23Z MESOANALYSIS INDICATED A SURFACE LOW NEAR MTO WITH AN ATTENDANT
WARM FRONT THAT EXTENDED SEWD INTO SRN IND /N OF SDF/. ASSOCIATED
COLD FRONT THEN STRETCHED NWD FROM THE LOW THROUGH THE CHI METRO
AREA WITH THE TRAILING PORTION OF THIS FEATURE EXTENDING SWWD
THROUGH CNTRL MO. LOCALIZED PRESSURE FALL CENTER / I.E. 3-4MB/3HRS /
HAS NOW MOVED EWD INTO CNTRL IL WHICH SUGGESTS THAT WARM FRONT
SHOULD CONTINUE TO LIFT NWD ACROSS SRN IND.

THE GREATEST TORNADO THREAT FOR THE NEXT HOUR OR SO WILL EXIST FROM
NEAR THE SURFACE LOW CENTER OVER W-CNTRL IND SWD AND EVENTUALLY SEWD
AS ONGOING CONVECTIVE LINE BEGINS TO INTERACT WITH RETREATING WARM
FRONT. HERE LOW-LEVEL WIND FIELDS REMAIN VERY FAVORABLE WITH 0-1KM
SHEAR/SRH VALUES OF 20-25KTS AND 150-250 M2/S2...RESPECTIVELY.

..MEAD.. 09/26/2003

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

ATTN...WFO...IND...ILX...LSX...

38828988 40078991 40288960 40348668 40118635 39008634
38808664 38668961

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 26, 12:21 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Christian, DeWitt and 23 more114 min
Sep 26, 1:20 PM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 26 more6 hr
Sep 26, 4:32 PM CDTMesoscale DiscussionSPCChampaign, Christian, Clark, Clay, Coles, Crawford and 19 more88 min
Sep 26, 4:50 PM CDTTornado WatchSPCBond, Champaign, Christian, Clark, Clay, Coles and 18 more5 hr
Sep 26, 5:06 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 26 more84 min
Sep 26, 6:10 PM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more7 hr
Sep 26, 5:45 PM CDTMesoscale DiscussionSPCBartholomew, Blackford, Brown, Dearborn, Decatur, Delaware and 22 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.