Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 656

May 1, 200324 counties in Illinois; 4 counties in Indiana; 7 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 1, 2003, 1:19 AM CDT for 24 counties in Illinois; 4 counties in Indiana; 7 counties in Missouri. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
May 1, 2003, 1:19 AM CDT (06:19 UTC)
Expired
May 1, 2003, 2:45 AM CDT
In force
86 min
Issued by
the Storm Prediction Center
All 35 counties

Adams County, IL, Brown County, IL, Cass County, IL, DeWitt County, IL, Ford County, IL, Fulton County, IL, Grundy County, IL, Iroquois County, IL, Kankakee County, IL, LaSalle County, IL, Livingston County, IL, Logan County, IL, Marshall County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Morgan County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Tazewell County, IL, Will County, IL, Woodford County, IL, Benton County, IN, Jasper County, IN, Lake County, IN, Newton County, IN, Audrain County, MO, Boone County, MO, Marion County, MO, Monroe County, MO, Pike County, MO, Ralls County, MO, Shelby County, MO

The radar

The Lincoln radar (KILX), 80 km from the middle of the area, began a volume at 06:21 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

Lincoln, IL (KILX), launched 00:00Z, 6.3 hours before the alert went out and 142 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 00:00Z on 2003-05-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1938 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 00:00Z on 2003-05-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 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
1938 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1356 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
215 m²/s²
Significant tornado parameter
0.8
Supercell composite
7.1

Open this sounding in Storm Lab

The text

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

196 
ACUS11 KWNS 010619
SWOMCD
SPC MCD 010619 
INZ000-ILZ000-MOZ000-010745-

MESOSCALE DISCUSSION 0656
NWS STORM PREDICTION CENTER NORMAN OK
0119 AM CDT THU MAY 01 2003

AREAS AFFECTED...NERN MO...NRN-CNTRL IL...NWRN IND

CONCERNING...SEVERE THUNDERSTORM WATCH 193...

VALID 010619Z - 010745Z

SERIES OF STRONG OUTFLOW BOUNDARIES CONTINUE MOVING ESEWD ACROSS ERN
PORTIONS OF WW 193 ATTM...FROM COMMA-HEAD LOW OVER SRN LAKE MICHIGAN
SWWD INTO CNTRL IL...WITH ANOTHER OUTFLOW EXTENDING FROM MESOLOW
OVER WRN TO A STRONG CELL NOW MOVING INTO SHELBY AND MONROE COUNTIES
OF ERN MO. AIRMASS FEEDING INTO AREAS OF STRONG LOW LEVEL
CONVERGENCE ALONG AND NORTH OF THE OUTFLOWS REMAINS UNSTABLE WITH AN
AXIS OF MLCAPE AROUND 1000 J/KG SITUATED FROM THE MS RIVER NEWD INTO
NRN IND. WHILE ISOLD CELLS COULD STILL POSE A HAIL/WIND
THREAT...ACTIVITY WILL CONTINUE TO MOVE SOUTH OF THE STRONGER
MIDLEVEL FLOW...AND DIURNAL COOLING WILL RESULT IN A SLOW DECREASE
IN INSTABILITY. THEREFORE...EXPECT CONVECTIVE INTENSITY ACROSS MUCH
OF WW 193 TO CONTINUE TO WANE. THIS SCENARIO IS ALSO SUPPORTED BY
LATEST SHORT-TERM MODEL GUIDANCE.

..CARBIN.. 05/01/2003

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

ATTN...WFO...IWX...IND...LOT...ILX...LSX...DVN...EAX...

39809231 40009124 40828954 41348917 41658714 40658701
39539008 38999153 38759243

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 30, 7:31 PM CDTMesoscale DiscussionSPCAdams, Bureau, Cook, DeKalb, DuPage, Grundy and 21 more119 min
Apr 30, 10:31 PM CDTMesoscale DiscussionSPCAdams, Bureau, Cook, DeKalb, DuPage, Grundy and 21 more89 min
Apr 30, 10:55 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Cass, DeWitt, Ford, Fulton and 22 more5 hr
May 1, 7:51 AM CDTMesoscale DiscussionSPCAlexander, Crawford, Edwards, Franklin, Gallatin, Hamilton and 14 more114 min
May 1, 9:35 AM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 9 more5 hr
May 1, 12:15 PM CDTSevere Thunderstorm WatchSPCGallatin, Hardin5 hr
May 1, 12:09 PM CDTMesoscale DiscussionSPCAdams, Allen, Blackford, Boone, Carroll, Cass and 26 more3 hr
May 1, 12:50 PM CDTSevere Thunderstorm WatchSPCAdams, Bartholomew, Blackford, Boone, Brown, Clay and 43 more5 hr
May 1, 3:10 PM CDTMesoscale DiscussionSPCAdams, Bartholomew, Blackford, Boone, Brown, Clay and 35 more95 min
Apr 30, 9:22 PM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Camden, Cass, Cedar and 19 more83 min
Apr 30, 9:30 PM CDTSevere Thunderstorm WatchSPCBarton, Bates, Benton, Camden, Carroll, Cass and 25 more6 hr
May 1, 12:00 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Camden, Carroll, Cass and 24 more90 min
May 1, 2:27 AM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Camden, Cedar and 17 more2 hr

Nearby

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