Alert archive / Illinois / Mesoscale Discussions in 2014

Mesoscale Discussion 444

April 28, 201414 counties in Illinois; 13 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 28, 2014, 1:43 AM CDT for 14 counties in Illinois; 13 counties in Missouri. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Apr 28, 2014, 1:43 AM CDT (06:43 UTC)
Expired
Apr 28, 2014, 3:15 AM CDT
In force
92 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 27 counties

Bond County, IL, Clinton County, IL, Franklin County, IL, Jackson County, IL, Jefferson County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Washington County, IL, Williamson County, IL, Cape Girardeau County, MO, City of Saint Louis, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Perry County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 62 km from the middle of the area, began a volume at 06:45 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 00:00Z, 6.7 hours before the alert went out and 257 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 00:00Z on 2014-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 295 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 00:00Z on 2014-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 161 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
295 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
836 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
161 m²/s²
0-3 km storm-relative helicity
157 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.4

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 27, 7:53 PM CDTTornado WatchSPCAlexander, Gallatin, Hardin, Jackson, Johnson, Massac and 5 more6 hr
Apr 27, 11:41 PM CDTMesoscale DiscussionSPCAlexander, Hardin, Johnson, Massac, Pope, Pulaski and 1 more94 min
Apr 28, 12:54 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 16 more2 hr
Apr 28, 1:11 PM CDTTornado WatchSPCAdams, Bond, Brown, Calhoun, Cass, Christian and 39 more7 hr
Apr 28, 3:13 PM CDTMesoscale DiscussionSPCAlexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 9 more2 hr
Apr 28, 3:38 PM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Bureau, Calhoun, Cass and 42 more2 hr
Apr 28, 6:10 PM CDTMesoscale DiscussionSPCBond, Bureau, Christian, Clay, Clinton, Coles and 51 more95 min
Apr 27, 7:29 PM CDTMesoscale DiscussionSPCButler, Dunklin, Mississippi, New Madrid, Pemiscot, Ripley and 2 more91 min
Apr 27, 8:40 PM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Camden, Carroll and 35 more65 min
Apr 27, 8:43 PM CDTMesoscale DiscussionSPCButler, Dunklin, Pemiscot62 min
Apr 27, 11:21 PM CDTMesoscale DiscussionSPCBarry, Camden, Christian, Dallas, Douglas, Greene and 13 more84 min
Apr 28, 1:43 AM CDTTornado WatchSPCDunklin, Pemiscot8 hr

Nearby

Mesoscale Discussions in Illinois, 2014Mesoscale Discussions in Missouri, 2014Every mesoscale discussion in 2014

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.