Alert archive / Missouri / Mesoscale Discussions in 2004

Mesoscale Discussion 1931

August 9, 20046 counties in Illinois; 16 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Aug 9, 2004, 1:29 PM CDT for 6 counties in Illinois; 16 counties in Missouri. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Aug 9, 2004, 1:29 PM CDT (18:29 UTC)
Expired
Aug 9, 2004, 3:00 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
All 22 counties

Adams County, IL, Brown County, IL, Cass County, IL, Pike County, IL, Schuyler County, IL, Scott County, IL, Audrain County, MO, Boone County, MO, Chariton County, MO, Cooper County, MO, Howard County, MO, Johnson County, MO, Lafayette County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Pettis County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saline County, MO, Shelby County, MO

The radar

The St Louis radar (KLSX), 150 km from the middle of the area, began a volume at 18:28 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 12:00Z, 6.5 hours before the alert went out and 307 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 2004-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 2004-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
6 J/kg
Mixed-layer CIN
-253 J/kg
Mixed-layer LCL
1257 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
75 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.

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Nearby

Mesoscale Discussions in Missouri, 2004Mesoscale Discussions in Illinois, 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.