Alert archive / Illinois / Mesoscale Discussions in 2012

Mesoscale Discussion 2082

October 22, 201227 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at Oct 22, 2012, 10:04 AM CDT for 27 counties in Illinois. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Oct 22, 2012, 10:04 AM CDT (15:04 UTC)
Expired
Oct 22, 2012, 11:00 AM CDT
In force
56 min
Issued by
the Storm Prediction Center
Chance of a watch
20%
All 27 counties

Bond County, IL, Champaign County, IL, Christian County, IL, Clinton County, IL, Coles County, IL, DeWitt County, IL, Douglas County, IL, Effingham County, IL, Fayette County, IL, Ford County, IL, Grundy County, IL, Iroquois County, IL, Kankakee County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, McLean County, IL, Montgomery County, IL, Moultrie County, IL, Piatt County, IL, Saint Clair County, IL, Sangamon County, IL, Shelby County, IL, Vermilion County, IL, Washington County, IL

The radar

The Lincoln radar (KILX), 56 km from the middle of the area, began a volume at 15:06 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, 3.1 hours before the alert went out and 28 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 2012-10-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 620 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 12:00Z on 2012-10-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
620 J/kg
Mixed-layer CIN
-91 J/kg
Mixed-layer LCL
653 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
276 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.

660 
ACUS11 KWNS 221505
SWOMCD
SPC MCD 221504
INZ000-ILZ000-MOZ000-221600-

MESOSCALE DISCUSSION 2082
NWS STORM PREDICTION CENTER NORMAN OK
1004 AM CDT MON OCT 22 2012

AREAS AFFECTED...SRN/CNTRL/ERN IL

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 221504Z - 221600Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ONGOING THUNDERSTORMS WILL CONTINUE TO TRACK
ESEWD...PRODUCING MARGINALLY SEVERE HAIL ACROSS SRN/CNTRL/ERN IL.
ALTHOUGH A WW IS NOT CURRENTLY ANTICIPATED...THE AREA WILL CONTINUE
TO BE MONITORED FOR A POSSIBLE INCREASE IN SEVERITY THIS AFTERNOON.

DISCUSSION...A WEAK LINE OF THUNDERSTORMS APPEARS TO BE PERSISTING
IN RESPONSE TO FORCING FOR ASCENT IN ASSOCIATION WITH AN UPPER WAVE
NOTED ON WV IMAGERY OVER ERN IA/WRN IL...AND AN MCV NOTED OVER NWRN
IL. MOIST LOW-LEVEL WSWLY WINDS NEAR 35-40 KT PER AREA VAD WIND
PROFILE DATA ARE LIKELY MAINTAINING WEAK ELEVATED
INSTABILITY...PARTICULARLY WITH THE SRN MOST EXTENT OF THE LINE OVER
SRN/CNTRL IL. HOWEVER...THE MOIST INFLOW MAY GRADUALLY DECREASE AS
THE PRIMARY FORCING FOR ASCENT PROGRESSES AWAY FROM THE REGION. WEAK
MID-LEVEL WINDS AND OTHERWISE MARGINAL MOISTURE PROFILES MAY HINDER
THE DEVELOPMENT OF AN ORGANIZED SEVERE THREAT...THOUGH ISOLATED
INSTANCES OF MARGINALLY SEVERE HAIL ARE POSSIBLE WITH STRONGER CORES
THAT CAN DEVELOP.

..DISPIGNA/MEAD.. 10/22/2012

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

ATTN...WFO...LOT...ILX...LSX...

LAT...LON   41298899 41338806 40938746 40578753 39838782 39238836
            38718894 38318935 38458995 38829020 40328934 41298899

Nearby

Mesoscale 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.