Alert archive / Illinois / Mesoscale Discussions in 2011

Mesoscale Discussion 1003

May 28, 201138 counties in Illinois; 28 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 28, 2011, 12:15 PM CDT for 38 counties in Illinois; 28 counties in Missouri. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
May 28, 2011, 12:15 PM CDT (17:15 UTC)
Expired
May 28, 2011, 1:45 PM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 66 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Effingham County, IL, Fayette County, IL, Fulton County, IL, Greene County, IL, Hancock County, IL, Jasper County, IL, Jersey County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Piatt County, IL, Pike County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Tazewell County, IL, Adair County, MO, Audrain County, MO, Boone County, MO, Caldwell County, MO, Carroll County, MO, Chariton County, MO, Clark County, MO, Daviess County, MO, Grundy County, MO, Howard County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Linn County, MO, Livingston County, MO, Macon County, MO, Marion County, MO, Monroe County, MO, Montgomery County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Ray County, MO, Saline County, MO, Schuyler County, MO, Scotland County, MO, Shelby County, MO, Sullivan County, MO

The radar

The St Louis radar (KLSX), 109 km from the middle of the area, began a volume at 17:17 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, 5.3 hours before the alert went out and 170 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 2011-05-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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 2011-05-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 91 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
505 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
91 m²/s²
0-3 km storm-relative helicity
121 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.

286 
ACUS11 KWNS 281715
SWOMCD
SPC MCD 281715 
INZ000-ILZ000-MOZ000-IAZ000-281845-

MESOSCALE DISCUSSION 1003
NWS STORM PREDICTION CENTER NORMAN OK
1215 PM CDT SAT MAY 28 2011

AREAS AFFECTED...NRN MO...CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 281715Z - 281845Z

ELEVATED CONVECTION HAS BEEN INCREASING IN THE LAST 1-2 HRS ACROSS
NRN MO INTO CNTRL IL. CONVECTIVE TRENDS WILL BE MONITORED FOR A
POSSIBLE WW.

AN INTENSE STORM IS NOTED OVER MONROE CO MISSOURI AS OF 17Z...WITH
ADDITIONAL ACTIVITY REDEVELOPING OVER NRN MO. MEANWHILE...AN
EXISTING CONVECTIVE CLUSTER CONTINUES TO PROGRESS EWD ACROSS CNTRL
IL. SFC OBJECTIVE ANALYSIS INDICATES THAT THIS ACTIVITY IS LIKELY
ROOTED IN THE 800-700 MB LAYER...WITH MU CAPE OF AROUND 1000 J/KG
AVAILABLE TO ORGANIZED UPDRAFTS. EFFECTIVE SHEAR OF 40-50 KTS WILL
SUPPORT STORM ORGANIZATION AND A POTENTIAL FOR HAIL...THOUGH
RELATIVELY WEAK LAPSE RATES WILL LIKELY LIMIT THE AREAL COVERAGE OF
SEVERE HAIL THREAT. IF COVERAGE BEGINS TO INCREASE MORE THAN
CURRENTLY ANTICIPATED...WW ISSUANCE MAY BE REQUIRED.

..DEAN.. 05/28/2011

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

ATTN...WFO...IND...ILX...LSX...DVN...DMX...EAX...

LAT...LON   38909227 39219414 40109421 40599253 40639104 40568985
            40498895 40288823 39828768 39298759 38948772 38808899
            38839139 38909227

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 28, 2:25 PM CDTSevere Thunderstorm WatchSPCChampaign, Christian, Clark, Coles, Crawford, Cumberland and 10 more5 hr
May 28, 3:42 PM CDTMesoscale DiscussionSPCChampaign, Christian, Clark, Coles, Crawford, Cumberland and 15 more93 min
May 28, 5:39 PM CDTMesoscale DiscussionSPCBond, Calhoun, Cass, Champaign, Christian, Clark and 28 more66 min
May 28, 2:50 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Cass, Cedar, Dade and 7 more85 min
May 28, 4:11 AM CDTSevere Thunderstorm WatchSPCBarton, Bates, Benton, Camden, Cedar, Dade and 11 more5 hr
May 28, 6:06 AM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Camden, Cedar, Cole and 13 more84 min
May 28, 6:34 PM CDTMesoscale DiscussionSPCBarton, Vernon116 min

Nearby

Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Missouri, 2011Every mesoscale discussion in 2011

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.