Alert archive / Missouri / Mesoscale Discussions in 2005

Mesoscale Discussion 631

April 21, 2005Adams County, Monroe County, Pike County, Illinois; 20 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2005, 3:28 PM CDT for Adams County, Monroe County, Pike County, Illinois; 20 counties in Missouri. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Apr 21, 2005, 3:28 PM CDT (20:28 UTC)
Expired
Apr 21, 2005, 5:00 PM CDT
In force
92 min
Issued by
the Storm Prediction Center
All 23 counties

Adams County, IL, Monroe County, IL, Pike County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Lincoln County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 77 km from the middle of the area, began a volume at 20:29 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

Lincoln, IL (KILX), launched 12:00Z, 8.5 hours before the alert went out and 276 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 2005-04-21Temperature 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, Lincoln, IL at 12:00Z on 2005-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
600 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
138 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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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 20, 7:03 PM CDTMesoscale DiscussionSPCBrown, Cass, Fulton, Hancock, Henderson, Henry and 12 more87 min
Apr 21, 1:10 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Calhoun, Cass, Clinton, Greene and 13 more6 hr
Apr 21, 5:22 PM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Johnson, Massac, Pope and 4 more53 min
Apr 21, 5:35 PM CDTSevere Thunderstorm WatchSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more7 hr
Apr 21, 5:52 PM CDTMesoscale DiscussionSPCCalhoun, Jersey, Madison, Monroe, Saint Clair53 min
Apr 21, 6:45 PM CDTSevere Thunderstorm WatchSPCBond, Calhoun, Clinton, Franklin, Greene, Hamilton and 10 more6 hr
Apr 21, 3:34 AM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Daviess, DeKalb, Gentry and 4 more116 min
Apr 21, 11:13 AM CDTMesoscale DiscussionSPCPlatte2 hr
Apr 21, 12:15 PM CDTMesoscale DiscussionSPCBoone, Callaway, Cole, Cooper, Crawford, Franklin and 12 more2 hr
Apr 21, 1:23 PM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Camden, Cedar and 22 more67 min
Apr 21, 1:45 PM CDTSevere Thunderstorm WatchSPCBarry, Barton, Bates, Benton, Camden, Cedar and 32 more5 hr
Apr 21, 3:05 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Carroll, Cass and 11 more85 min
Apr 21, 3:35 PM CDTTornado WatchSPCAndrew, Atchison, Bates, Benton, Buchanan, Caldwell and 19 more7 hr
Apr 21, 4:51 PM CDTMesoscale DiscussionSPCBuchanan, Clay, Clinton, Platte54 min
Apr 21, 5:14 PM CDTMesoscale DiscussionSPCMcDonald2 hr
Apr 21, 6:10 PM CDTTornado WatchSPCBarry, Barton, Camden, Cedar, Christian, Crawford and 27 more7 hr
Apr 21, 6:51 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Cass, Clay and 12 more84 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.