Alert archive / Iowa / Mesoscale Discussions in 2003

Mesoscale Discussion 871

May 8, 20036 counties in Illinois; 30 counties in Iowa; 15 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 8, 2003, 11:50 PM CDT for 6 counties in Illinois; 30 counties in Iowa; 15 counties in Missouri. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
May 8, 2003, 11:50 PM CDT (04:50 UTC)
Expired
May 9, 2003, 12:45 AM CDT
In force
55 min
Issued by
the Storm Prediction Center
All 51 counties

Appanoose County, IA, Benton County, IA, Black Hawk County, IA, Buchanan County, IA, Davis County, IA, Des Moines County, IA, Grundy County, IA, Henry County, IA, Iowa County, IA, Jasper County, IA, Jefferson County, IA, Johnson County, IA, Keokuk County, IA, Lee County, IA, Linn County, IA, Louisa County, IA, Lucas County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Monroe County, IA, Muscatine County, IA, Polk County, IA, Poweshiek County, IA, Tama County, IA, Van Buren County, IA, Wapello County, IA, Warren County, IA, Washington County, IA, Wayne County, IA, Adams County, IL, Brown County, IL, Hancock County, IL, Henderson County, IL, Pike County, IL, Scott County, IL, Adair County, MO, Chariton County, MO, Clark County, MO, Knox County, MO, Lewis County, MO, Linn County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Putnam County, MO, Ralls County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO

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, 4.8 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 00:00Z on 2003-05-09Temperature 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, Davenport, at 00:00Z on 2003-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 213 square meters per square second.1939587897117Sfc1 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
1197 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
483 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.

771 
ACUS11 KWNS 090450
SWOMCD
SPC MCD 090450 
ILZ000-MOZ000-IAZ000-090545-

MESOSCALE DISCUSSION 0871
NWS STORM PREDICTION CENTER NORMAN OK
1150 PM CDT THU MAY 08 2003

AREAS AFFECTED...SRN-ERN IA/NERN MO/FAR WEST CENTRAL IL

CONCERNING...SEVERE THUNDERSTORM WATCH 312...

VALID 090450Z - 090545Z

A FEW STORMS WILL CONTINUE TO POSE A SEVERE THREAT OVER SRN-ERN IA/
NERN MO AND INTO FAR WEST CENTRAL IL DURING THE NEXT 1-2 HOURS...
WITH THE GREATEST THREAT OVER NERN MO INTO FAR WEST CENTRAL IL.

REGIONAL RADARS SHOW A STRONG STORM OVER THE CENTRAL MO COUNTIES OF
BOONE AND AUDRAIN MOVING TO THE NE AT 45 KT.  CURRENT RADAR TRENDS
INDICATE THIS STORM WILL MOVE INTO THE SERN PORTION OF WW 312
BETWEEN 0530-0630Z...WITH A CONTINUED THREAT OF HAIL/DAMAGING WINDS
AND AN ISOLATED TORNADO.  A FEW STRONG/SEVERE STORMS REMAIN POSSIBLE
FURTHER NORTH INTO IA.	HOWEVER...GIVEN THE TRACK OF THE CENTRAL MO
STORM AND AN EXPECTED DIMINISHING TREND IN THE OVERALL SEVERE
THREAT...WW 312 WILL BE ALLOWED TO EXPIRE AT 06Z.

..PETERS.. 05/09/2003

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

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

41639401 41969335 42729258 42719149 39499041 39469315

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 8, 7:06 PM CDTMesoscale DiscussionSPCHamilton, White54 min
May 8, 7:55 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Hancock, Henderson, Pike, Scott5 hr
May 8, 9:10 PM CDTSevere Thunderstorm WatchSPCBureau, Carroll, Cass, Champaign, DeKalb, DeWitt and 32 more6 hr
May 8, 9:27 PM CDTMesoscale DiscussionSPCAdams, Brown, Bureau, Carroll, Cass, Champaign and 40 more93 min
May 9, 12:05 AM CDTSevere Thunderstorm WatchSPCBond, Brown, Calhoun, Cass, Champaign, Christian and 28 more6 hr
May 9, 2:02 PM CDTMesoscale DiscussionSPCEdwards, Lawrence, Wabash, Wayne, White2 hr
May 9, 2:48 PM CDTMesoscale DiscussionSPCClinton, Edwards, Franklin, Gallatin, Hamilton, Hardin and 15 more117 min
May 9, 4:17 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 21 more28 min
May 9, 4:45 PM CDTTornado WatchSPCCalhoun, Greene, Morgan, Pike, Scott6 hr
May 9, 5:44 PM CDTMesoscale DiscussionSPCChampaign, Christian, Clark, Coles, Cumberland, DeWitt and 15 more31 min
May 9, 6:05 PM CDTTornado WatchSPCBond, Champaign, Christian, Clark, Clinton, Coles and 13 more5 hr
May 8, 7:13 PM CDTMesoscale DiscussionSPCAndrew, Barton, Bates, Buchanan, Caldwell, Carroll and 23 more2 hr
May 8, 9:00 PM CDTTornado WatchSPCAudrain, Benton, Boone, Callaway, Camden, Cole and 26 more5 hr

Nearby

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