Alert archive / Missouri / Mesoscale Discussions in 2012

Mesoscale Discussion 339

March 23, 201224 counties in Illinois; 31 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 23, 2012, 6:43 PM CDT for 24 counties in Illinois; 31 counties in Missouri. It was in force for 32 min.

The area

The outline as issued.

The facts

Issued
Mar 23, 2012, 6:43 PM CDT (23:43 UTC)
Expired
Mar 23, 2012, 7:15 PM CDT
In force
32 min
Issued by
the Storm Prediction Center
All 55 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jefferson County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Perry County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Sangamon County, IL, Scott County, IL, Washington County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Carroll County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Jefferson County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Macon County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pettis County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Saline County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 80 km from the middle of the area, began a volume at 23:44 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, 11.7 hours before the alert went out and 275 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 2012-03-23Temperature 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 2012-03-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 29 square meters per square second.1939587897Sfc1 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
808 m above ground
0-6 km bulk shear
49 kt
0-1 km storm-relative helicity
29 m²/s²
0-3 km storm-relative helicity
57 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.

216 
ACUS11 KWNS 232344
SWOMCD
SPC MCD 232343
ILZ000-MOZ000-240015-

MESOSCALE DISCUSSION 0339
NWS STORM PREDICTION CENTER NORMAN OK
0643 PM CDT FRI MAR 23 2012

AREAS AFFECTED...PARTS OF CENTRAL/SRN IL INTO NRN/CENTRAL MO

CONCERNING...SEVERE THUNDERSTORM WATCH 101...

VALID 232343Z - 240015Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 101
CONTINUES.

HOWEVER...THIS SEVERE WEATHER THREAT WILL CONTINUE TO WEAKEN ACROSS
THE REMAINDER OF WW 101...ALLOWING THIS WATCH TO EXPIRE AS SCHEDULED
AT 00Z.  ADDITIONAL STORMS THAT HAVE FORMED FARTHER W OVER NRN/
CENTRAL MO WILL ALSO DIMINISH IN INTENSITY THIS EVENING.

REGIONAL RADARS EARLY THIS EVENING SHOWED TSTMS EXTENDING FROM
CENTRAL/NERN MO INTO WRN/CENTRAL IL.  THIS ACTIVITY IS BEING AIDED
BY ASCENT ATTENDANT TO A FEW VORTICITY CENTERS ROTATING WITHIN THE
CLOSED MID-UPPER LEVEL LOW OVER ERN/SERN MO.  WEAK DEEP LAYER SHEAR
AND A FURTHER DECREASE IN INSTABILITY THIS EVENING WILL REDUCE ANY
SEVERE WEATHER THREAT.

..PETERS.. 03/23/2012

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

ATTN...WFO...PAH...ILX...LSX...DVN...SGF...EAX...

LAT...LON   39959301 40219134 40079024 39758904 38658853 37808909
            37808983 38039082 38429214 38619305 38739349 39109362
            39669353 39959301

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 23, 9:46 AM CDTMesoscale DiscussionSPCAlexander, Clay, Crawford, Edwards, Franklin, Gallatin and 20 more119 min
Mar 23, 11:44 AM CDTSevere Thunderstorm WatchSPCAlexander, Bond, Champaign, Christian, Clark, Clay and 36 more7 hr
Mar 23, 1:28 PM CDTMesoscale DiscussionSPCClark, Clay, Coles, Crawford, Cumberland, Edwards and 10 more62 min
Mar 23, 1:58 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Cass, Fulton, Greene and 12 more2 hr
Mar 23, 3:17 PM CDTMesoscale DiscussionSPCChampaign, Clark, Coles, Crawford, Cumberland, Douglas and 9 more58 min
Mar 23, 3:39 PM CDTSevere Thunderstorm WatchSPCFord, Iroquois, Kankakee4 hr

Nearby

Mesoscale Discussions in Missouri, 2012Mesoscale Discussions in Illinois, 2012Every mesoscale discussion in 2012

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.