Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 1721

July 8, 200320 counties in Illinois; 8 counties in Iowa; 15 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Jul 8, 2003, 6:46 PM CDT for 20 counties in Illinois; 8 counties in Iowa; 15 counties in Missouri. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Jul 8, 2003, 6:46 PM CDT (23:46 UTC)
Expired
Jul 8, 2003, 9:45 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
All 43 counties

Appanoose County, IA, Davis County, IA, Decatur County, IA, Lee County, IA, Ringgold County, IA, Taylor County, IA, Van Buren County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Cass County, IL, Champaign County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Fulton County, IL, Hancock County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Sangamon County, IL, Schuyler County, IL, Tazewell County, IL, Adair County, MO, Clark County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Knox County, MO, Lewis County, MO, Marion County, MO, Mercer County, MO, Nodaway County, MO, Putnam County, MO, Schuyler County, MO, Scotland County, MO, Sullivan County, MO, Worth County, MO

The radar

The Quad Cities radar (KDVN), 182 km from the middle of the area, began a volume at 23:50 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 nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.8 hours before the alert went out and 186 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, Davenport, at 12:00Z on 2003-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 823 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2003-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 101 square meters per square second.193958Sfc1 km3 km6 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
823 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
796 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
101 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.6

Open this sounding in Storm Lab

The text

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

381 
ACUS11 KWNS 082346
SWOMCD
SPC MCD 082346 
ILZ000-IAZ000-MOZ000-090245-

MESOSCALE DISCUSSION 1721
NWS STORM PREDICTION CENTER NORMAN OK
0646 PM CDT TUE JUL 08 2003

AREAS AFFECTED...IA/MO BORDER REGION...PORTIONS NERN MO...CENTRAL IL

CONCERNING...HEAVY RAINFALL 

VALID 082346Z - 090245Z

HEAVY RAIN RATES -- COMMONLY 1.5-2.5 INCHES/HOUR BUT LOCALLY OVER 3
INCHES/HOUR -- WILL AFFECT MUCH OF CORRIDOR FROM NODAWAY/ANDREW
COUNTIES MO EWD TOWARD DAVIS COUNTY IA AND SCOTLAND COUNTY MO...THEN
ESEWD ACROSS IL TOWARD CMI AREA.  THIS INCLUDES IRK...UIN...SPI AND
EWD ALONG I-72 TO NEAR INDIANA BORDER. TRAINING/MERGING OF CELLS
WILL ENHANCE HAZARD.  THIS INCLUDES ADDITIONAL HEAVY RAIN PRODUCING
TSTMS THAT ARE FCST TO MOVE IN SERIES...ACROSS AREAS OF NERN MO
ALREADY UNDER FLASH FLOOD WARNINGS FROM PRIOR AND CURRENT ACTIVITY.

SFC ANALYSIS SHOWS OUTFLOW-MODIFIED...QUASISTATIONARY BAROCLINIC
ZONE FROM SWRN IA ESEWD ACROSS IRK AREA TO NEAR MTO.  MOST
CONVECTION WILL REMAIN ALONG AND N OF THIS BOUNDARY EXCEPT OVER NWRN
MO.  EXPECT ALREADY FAVORABLE SR INFLOW TO CONTINUE AND PERHAPS
INCREASE OVER NEXT FEW HOURS AS BOUNDARY LAYER DECOUPLES... FOCUSING
MOIST 30-35 KT LLJ INTO REGION.  INFLOW-LAYER AIR MASS WILL BE
CHARACTERIZED BY ROUGHLY 1.76 INCH PW AND 13-16 G/KG MEAN MIXING
RATIO...ALONG WITH MUCAPE 2000-3000 J/KG...FAVORING PROFUSE PRECIP
PRODUCTION.

REF SPC WW 687 FOR SEVERE TSTM POTENTIAL.

..EDWARDS.. 07/08/2003

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

ATTN...WFO...ILX...LSX...DVN...DMX...EAX...OAX...

40079493 40329515 40659513 41009436 41029338 40658966
40298810 39848762 39688768 39558934

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 7, 7:16 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, DeKalb, DuPage, Henry and 9 more3 hr
Jul 7, 7:40 PM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 20 more3 hr
Jul 7, 10:18 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 21 more57 min
Jul 7, 11:00 PM CDTSevere Thunderstorm WatchSPCCook, Iroquois, Kankakee, Lake, Vermilion5 hr
Jul 7, 11:50 PM CDTMesoscale DiscussionSPCIroquois, Vermilion85 min
Jul 8, 8:50 AM CDTMesoscale DiscussionSPCAdams, Brown, Hancock, Henderson, McDonough, Mercer and 2 more115 min
Jul 8, 9:50 AM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 28 more5 hr
Jul 8, 12:25 PM CDTMesoscale DiscussionSPCClark, Clay, Crawford, Cumberland, Edwards, Effingham and 4 more95 min
Jul 8, 12:59 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 28 more91 min
Jul 8, 1:21 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Champaign, Christian and 25 more24 min
Jul 8, 1:45 PM CDTTornado WatchSPCAdams, Brown, Bureau, Carroll, Cass, Champaign and 48 more5 hr
Jul 8, 3:40 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Cass, Champaign, Christian and 41 more95 min
Jul 8, 6:15 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, Champaign, Christian, Clark and 37 more5 hr
Jul 7, 10:15 PM CDTMesoscale DiscussionSPCCrawford, Harrison, Ida, Monona, Plymouth, Pottawattamie and 1 more3 hr
Jul 7, 10:20 PM CDTSevere Thunderstorm WatchSPCCherokee, Crawford, Fremont, Harrison, Ida, Mills and 4 more7 hr
Jul 7, 11:25 PM CDTMesoscale DiscussionSPCClay, Dickinson, Emmet, Kossuth, Lyon, O'Brien and 3 more2 hr
Jul 7, 11:40 PM CDTSevere Thunderstorm WatchSPCClay, Dickinson, Lyon, O'Brien, Osceola, Sioux5 hr
Jul 8, 1:34 AM CDTMesoscale DiscussionSPCCherokee, Crawford, Fremont, Harrison, Ida, Mills and 5 more116 min
Jul 8, 2:52 AM CDTMesoscale DiscussionSPCBenton, Black Hawk, Boone, Bremer, Buchanan, Buena Vista and 49 more113 min
Jul 8, 5:13 PM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Cass, Clarke and 19 more92 min

Nearby

Mesoscale Discussions in Illinois, 2003Mesoscale Discussions in Missouri, 2003Mesoscale Discussions in Iowa, 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.