Alert archive / Indiana / Mesoscale Discussions in 2004

Mesoscale Discussion 2039

August 18, 20045 states

The Storm Prediction Center issued this mesoscale discussion at Aug 18, 2004, 5:17 PM CDT for 5 states. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
Aug 18, 2004, 5:17 PM CDT (22:17 UTC)
Expired
Aug 18, 2004, 6:45 PM CDT
In force
88 min
Issued by
the Storm Prediction Center
All 142 counties

Lee County, IA, Adams County, IL, Bond County, IL, Brown County, IL, Cass 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, Edwards County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Henderson County, IL, Iroquois County, IL, Jasper County, IL, Knox County, IL, Lawrence County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Marion County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Putnam County, IL, Richland County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Vermilion County, IL, Wabash County, IL, Warren County, IL, Woodford County, IL, Bartholomew County, IN, Benton County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Clark County, IN, Clay County, IN, Clinton County, IN, Crawford County, IN, Daviess County, IN, Dearborn County, IN, Decatur County, IN, Delaware County, IN, Dubois County, IN, Fayette County, IN, Floyd County, IN, Fountain County, IN, Franklin County, IN, Gibson County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Harrison County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Ohio County, IN, Orange County, IN, Owen County, IN, Parke County, IN, Perry County, IN, Pike County, IN, Putnam County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Spencer County, IN, Sullivan County, IN, Switzerland County, IN, Tippecanoe County, IN, Tipton County, IN, Union County, IN, Vermillion County, IN, Vigo County, IN, Warren County, IN, Warrick County, IN, Washington County, IN, Wayne County, IN, Anderson County, KY, Boone County, KY, Bracken County, KY, Bullitt County, KY, Campbell County, KY, Carroll County, KY, Franklin County, KY, Gallatin County, KY, Grant County, KY, Harrison County, KY, Henry County, KY, Jefferson County, KY, Kenton County, KY, Meade County, KY, Oldham County, KY, Owen County, KY, Pendleton County, KY, Scott County, KY, Shelby County, KY, Spencer County, KY, Trimble County, KY, Woodford County, KY, Butler County, OH, Clermont County, OH, Hamilton County, OH, Preble County, OH

The radar

The Indianapolis radar (KIND), 59 km from the middle of the area, began a volume at 22:20 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, 10.3 hours before the alert went out and 161 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 2004-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 648 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 2004-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 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
648 J/kg
Mixed-layer CIN
-86 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
50 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.

679 
ACUS11 KWNS 182218
SWOMCD
SPC MCD 182217 
OHZ000-KYZ000-INZ000-ILZ000-MOZ000-IAZ000-182345-

MESOSCALE DISCUSSION 2039
NWS STORM PREDICTION CENTER NORMAN OK
0517 PM CDT WED AUG 18 2004

AREAS AFFECTED...CENTRAL AND SERN IL / SRN IN / NRN KY

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 182217Z - 182345Z

STORMS CONTINUE TO DEVELOP IN AN AXIS FROM CENTRAL IL SEWD INTO SRN
IND WHERE FAVORABLE ENVIRONMENT FOR SEVERE STORMS EXISTS.  WW WILL
LIKELY BE ISSUED FOR THIS REGION.

AXIS OF NEAR 70 DEWPOINTS ACROSS SRN IL / SRN IND / NRN OH COMBINED
WITH TEMPERATURES AROUND 90 HAS RESULTED IN A MODERATELY UNSTABLE
AIRMASS ACROSS THIS REGION /MEAN-LAYER CAPE 2000 TO 2500 J/KG/.

WITH WEAK MID-LEVEL FEATURE MOVING ACROSS NERN IL / NWRN IND ATTM
AND AXIS OF FAVORABLE INSTABILITY...EXPECT STORMS TO CONTINUE ACROSS
THIS AREA FOR THE NEXT SEVERAL HOURS.  WITH AREA VWPS INDICATING
WIND FIELD SUPPORTIVE OF SUPERCELLS -- INCLUDING ILX /CENTRAL IL/
WHERE WINDS INCREASE WITH HEIGHT TO 40 KTS AT 3 KM...STORMS CAPABLE
OF PRODUCING LARGE HAIL AND DAMAGING WINDS CAN BE EXPECTED.

..GOSS.. 08/18/2004

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

ATTN...WFO...ILN...LMK...IWX...IND...PAH...LOT...ILX...LSX...DVN...

40128499 39038382 38098447 37908542 37898676 39419116
40599165 41308964 40548623

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 17, 7:48 PM CDTMesoscale DiscussionSPCFord, Grundy, Iroquois, Kankakee, Livingston, Will117 min
Aug 18, 1:39 PM CDTMesoscale DiscussionSPCAdams, Brown, Cass, Champaign, Christian, Clark and 28 more96 min
Aug 18, 4:17 PM CDTMesoscale DiscussionSPCHancock, Henderson, Mercer, Rock Island, Warren118 min
Aug 18, 5:35 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, Champaign, Christian, Clark and 28 more5 hr
Aug 18, 12:27 PM CDTMesoscale DiscussionSPCAllamakee, Howard, Winneshiek63 min
Aug 18, 1:10 PM CDTSevere Thunderstorm WatchSPCAllamakee, Bremer, Chickasaw, Clayton, Fayette, Floyd and 2 more7 hr
Aug 18, 3:46 PM CDTMesoscale DiscussionSPCAllamakee, Bremer, Butler, Chickasaw, Clayton, Fayette and 3 more59 min
Aug 18, 4:50 PM CDTSevere Thunderstorm WatchSPCAppanoose, Davis, Decatur, Henry, Jefferson, Lee and 7 more6 hr
Aug 18, 5:52 PM CDTMesoscale DiscussionSPCClayton, Fayette113 min
Aug 18, 3:03 PM CDTMesoscale DiscussionSPCAllen, Ashland, Auglaize, Champaign, Crawford, Cuyahoga and 22 more57 min
Aug 18, 5:01 PM CDTMesoscale DiscussionSPCAdams, Ashland, Ashtabula, Athens, Carroll, Clinton and 40 more89 min

Nearby

Mesoscale Discussions in Indiana, 2004Mesoscale Discussions in Illinois, 2004Mesoscale Discussions in Kentucky, 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.