Alert archive / Missouri / Mesoscale Discussions in 2005

Mesoscale Discussion 645

April 21, 20056 counties in Illinois; 44 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2005, 10:25 PM CDT for 6 counties in Illinois; 44 counties in Missouri. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Apr 21, 2005, 10:25 PM CDT (03:25 UTC)
Expired
Apr 21, 2005, 11:30 PM CDT
In force
65 min
Issued by
the Storm Prediction Center
All 50 counties

Calhoun County, IL, Jersey County, IL, Madison County, IL, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Audrain County, MO, Bollinger County, MO, Butler County, MO, Callaway County, MO, Camden County, MO, Carter County, MO, Christian County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Montgomery County, MO, Oregon County, MO, Osage County, MO, Perry County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Ralls County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shannon County, MO, Stone County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO

The radar

The St Louis radar (KLSX), 133 km from the middle of the area, began a volume at 03:27 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

Springfield, MO (KSGF), launched 00:00Z, 3.4 hours before the alert went out and 222 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, Springfield, MO at 00:00Z on 2005-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1218 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, Springfield, MO at 00:00Z on 2005-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 81 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
1218 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
1229 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
81 m²/s²
0-3 km storm-relative helicity
150 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.4

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 8:03 PM CDTMesoscale DiscussionSPCBond, Calhoun, Clinton, Franklin, Hamilton, Jefferson and 10 more87 min
Apr 21, 8:19 PM CDTMesoscale DiscussionSPCAlexander, Johnson, Massac, Pope, Pulaski, Saline and 1 more86 min
Apr 21, 11:50 PM CDTSevere Thunderstorm WatchSPCClinton, Edwards, Franklin, Hamilton, Jackson, Jefferson and 9 more6 hr
Apr 22, 3:09 AM CDTMesoscale DiscussionSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more66 min
Apr 22, 10:56 AM CDTMesoscale DiscussionSPCChristian, Clark, Clay, Coles, Crawford, Cumberland and 15 more94 min
Apr 22, 1:30 PM CDTSevere Thunderstorm WatchSPCChampaign, Clark, Clay, Coles, Crawford, Cumberland and 19 more8 hr
Apr 21, 7:47 PM CDTMesoscale DiscussionSPCBarry, Barton, Camden, Cedar, Christian, Dade and 22 more88 min
Apr 21, 9:50 PM CDTMesoscale DiscussionSPCCaldwell, Carroll, Cass, Clay, Clinton, Daviess and 8 more55 min

Nearby

Mesoscale Discussions in Missouri, 2005Mesoscale Discussions in Illinois, 2005Every mesoscale discussion in 2005

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.