Alert archive / Illinois / Mesoscale Discussions in 2016

Mesoscale Discussion 285

March 30, 201625 counties in Illinois; 19 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 30, 2016, 1:42 PM CDT for 25 counties in Illinois; 19 counties in Missouri. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 30, 2016, 1:42 PM CDT (18:42 UTC)
Expired
Mar 30, 2016, 3:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
5%
All 44 counties

Bond County, IL, Calhoun County, IL, Cass County, IL, Christian County, IL, Clinton County, IL, Effingham County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Sangamon County, IL, Scott County, IL, Shelby County, IL, Washington County, IL, Callaway County, MO, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Lincoln County, MO, Maries County, MO, Montgomery County, MO, Osage County, MO, Phelps County, MO, Pike County, MO, Pulaski County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 24 km from the middle of the area, began a volume at 18:43 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, 6.7 hours before the alert went out and 218 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 2016-03-30Temperature 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 2016-03-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 454 square meters per square second.19395878Sfc1 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
1966 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
454 m²/s²
0-3 km storm-relative helicity
465 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

577 
ACUS11 KWNS 301843
SWOMCD
SPC MCD 301842 
ILZ000-MOZ000-302045-

MESOSCALE DISCUSSION 0285
NWS STORM PREDICTION CENTER NORMAN OK
0142 PM CDT WED MAR 30 2016

AREAS AFFECTED...PORTIONS OF ERN MO AND WRL/CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 301842Z - 302045Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...AN ISOLATED LARGE HAIL THREAT SHOULD CONTINUE THROUGH THE
AFTERNOON WITH ONGOING ELEVATED THUNDERSTORMS. DUE TO THE MARGINAL
NATURE OF THE SEVERE THREAT...WW ISSUANCE IS UNLIKELY.

DISCUSSION...WITHIN SWLY FLOW ALOFT...A CLUSTER OF STRONG TO
OCCASIONALLY SEVERE THUNDERSTORMS ASSOCIATED WITH A LOW-AMPLITUDE
SHORTWAVE TROUGH IS MOVING NEWD ACROSS PORTIONS OF ERN MO/WRN IL AS
OF 1840Z. THIS ACTIVITY IS OCCURRING ABOVE A STABLE LOW-LEVEL
AIRMASS...WITH STEEP MID-LEVEL LAPSE RATES OF 7.0-8.0 DEG C/KM
SUPPORTING WEAK TO MODERATE MUCAPE. GIVEN A UNIDIRECTIONAL WIND
FIELD WITHIN THE UNSTABLE LAYER ALOFT THAT IS ALSO STRENGTHENING
WITH HEIGHT...ISOLATED INSTANCES OF SEVERE HAIL SHOULD BE THE MAIN
SEVERE THREAT OVER THE NEXT SEVERAL HOURS ACROSS THE MCD AREA. AS
THESE THUNDERSTORMS MOVE NEWD INTO CNTRL IL...THEY SHOULD ENCOUNTER
INCREASINGLY MARGINAL ELEVATED INSTABILITY...WITH A LESSENING SEVERE
RISK.

..GLEASON/THOMPSON.. 03/30/2016

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

ATTN...WFO...PAH...ILX...LSX...SGF...

LAT...LON   38139245 38909200 39599113 40128991 40118942 39828854
            39368828 38308923 37639046 37669217 38139245

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 30, 11:57 AM CDTMesoscale DiscussionSPCBarry, Christian, Douglas, Howell, McDonald, Ozark and 2 more63 min
Mar 30, 2:56 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Bates, Buchanan, Caldwell, Cass and 11 more2 hr
Mar 30, 3:52 PM CDTSevere Thunderstorm WatchSPCAndrew, Buchanan, Holt, Platte3 hr
Mar 30, 6:22 PM CDTMesoscale DiscussionSPCBarton, Cedar, Dade, Jasper, McDonald, Newton and 2 more53 min

Nearby

Mesoscale Discussions in Illinois, 2016Mesoscale Discussions in Missouri, 2016Every mesoscale discussion in 2016

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.