Alert archive / Illinois / Mesoscale Discussions in 2003

Mesoscale Discussion 928

May 10, 200314 counties in Illinois; 14 counties in Iowa; 7 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at May 10, 2003, 8:18 PM CDT for 14 counties in Illinois; 14 counties in Iowa; 7 counties in Wisconsin. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
May 10, 2003, 8:18 PM CDT (01:18 UTC)
Expired
May 10, 2003, 10:15 PM CDT
In force
117 min
Issued by
the Storm Prediction Center
All 35 counties

Cedar County, IA, Clayton County, IA, Clinton County, IA, Delaware County, IA, Des Moines County, IA, Dubuque County, IA, Henry County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Louisa County, IA, Muscatine County, IA, Scott County, IA, Bureau County, IL, Carroll County, IL, Henderson County, IL, Henry County, IL, Jo Daviess County, IL, Knox County, IL, Mercer County, IL, Ogle County, IL, Peoria County, IL, Rock Island County, IL, Stark County, IL, Stephenson County, IL, Warren County, IL, Whiteside County, IL, Crawford County, WI, Dane County, WI, Grant County, WI, Green County, WI, Iowa County, WI, Lafayette County, WI, Richland County, WI

The radar

The Quad Cities radar (KDVN), 46 km from the middle of the area, began a volume at 01:19 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

Davenport, (KDVN), launched 00:00Z, 1.3 hours before the alert went out and 41 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 00:00Z on 2003-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1566 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, Davenport, at 00:00Z on 2003-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 234 square meters per square second.1939587897Sfc1 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
1566 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
910 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
234 m²/s²
0-3 km storm-relative helicity
259 m²/s²
Significant tornado parameter
2.8
Supercell composite
12.7

Open this sounding in Storm Lab

The text

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

414 
ACUS11 KWNS 110119
SWOMCD
SPC MCD 110118 
WIZ000-ILZ000-IAZ000-110315-

MESOSCALE DISCUSSION 0928
NWS STORM PREDICTION CENTER NORMAN OK
0818 PM CDT SAT MAY 10 2003

AREAS AFFECTED...ERN IA THROUGH SRN/CNTRL WI 

CONCERNING...TORNADO WATCH 346...347...

VALID 110118Z - 110315Z

TORNADO THREAT IS EXPECTED TO REMAIN HIGH ESPECIALLY ACROSS PARTS OF
ERN IA NRN IL AND SRN WI NEXT FEW HOURS AS SUPERCELLS CONTINUE
DEVELOPING NEWD.

SURFACE LOW CONTINUES TO DEEPEN ACROSS ERN IA WITH PRESSURE FALLS
FROM ERN IA THROUGH SRN WI AND NWRN IL. LOW LEVEL FLOW CONTINUES TO
STRENGTHEN AND THE ATMOSPHERE IS DESTABILIZING NWD WITH TIME ALONG
AND S OF THE WARM FRONT THAT EXTENDS EWD FROM THE LOW THROUGH SRN
WI. IN RESPONSE TO THE DEEPENING SURFACE LOW...THE BOUNDARY LAYER
FLOW HAS ACCELERATED AND BACKED...RESULTING IN VERY FAVORABLE
HODOGRAPHS FOR TORNADIC SUPERCELLS. 


..DIAL.. 05/11/2003

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

ATTN...WFO...LOT...ILX...MKX...DVN...ARX...

40618957 40759165 42789184 43529041 43168923 42058928

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 10, 7:06 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Hardin, Jackson, Johnson, Massac and 7 more54 min
May 10, 8:05 PM CDTTornado WatchSPCBoone, Cook, DeKalb, DuPage, Ford, Grundy and 12 more6 hr
May 10, 8:41 PM CDTMesoscale DiscussionSPCCrawford, Lawrence, Richland, Wabash2 hr
May 10, 8:45 PM CDTTornado WatchSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 10 more5 hr
May 10, 9:10 PM CDTTornado WatchSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 45 more5 hr
May 10, 9:35 PM CDTTornado WatchSPCBureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 11 more3 hr
May 10, 10:56 PM CDTMesoscale DiscussionSPCBoone, Bureau, Cook, DeKalb, DuPage, Ford and 19 more94 min
May 11, 1:46 AM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 42 more89 min

Nearby

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