Alert archive / Illinois / Mesoscale Discussions in 2012

Mesoscale Discussion 202

March 2, 201236 counties in Illinois; 10 counties in Indiana; 4 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Mar 2, 2012, 4:25 AM CST for 36 counties in Illinois; 10 counties in Indiana; 4 counties in Missouri. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Mar 2, 2012, 4:25 AM CST (10:25 UTC)
Expired
Mar 2, 2012, 6:00 AM CST
In force
95 min
Issued by
the Storm Prediction Center
All 50 counties

Bond County, IL, Calhoun County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Greene County, IL, Hamilton County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Moultrie County, IL, Perry County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Shelby County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Clay County, IN, Daviess County, IN, Gibson County, IN, Greene County, IN, Knox County, IN, Martin County, IN, Owen County, IN, Pike County, IN, Sullivan County, IN, Vigo County, IN, City of Saint Louis, MO, Jefferson County, MO, Saint Charles County, MO, Saint Louis County, MO

The radar

The Evansville,IN radar (KVWX), 127 km from the middle of the area, began a volume at 10:25 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 00:00Z, 10.4 hours before the alert went out and 142 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 2012-03-02Temperature 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 00:00Z on 2012-03-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 square meters per square second.1939587897117136Sfc1 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
2012 m above ground
0-6 km bulk shear
70 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
380 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.

864 
ACUS11 KWNS 021025
SWOMCD
SPC MCD 021025 
INZ000-ILZ000-MOZ000-021200-

MESOSCALE DISCUSSION 0202
NWS STORM PREDICTION CENTER NORMAN OK
0425 AM CST FRI MAR 02 2012

AREAS AFFECTED...ERN MO...SCNTRL IL AND SW IND

CONCERNING...SEVERE THUNDERSTORM WATCH 54...

VALID 021025Z - 021200Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 54
CONTINUES.

A THREAT FOR LARGE HAIL AND ISOLATED WIND DAMAGE WILL INCREASE
ACROSS THE ST LOUIS AREA ENEWD ACROSS SCNTRL IL AND SW IND. WW
ISSUANCE WILL LIKELY BE NEEDED EAST OF THE CURRENT WW 54 BEFORE 12Z.

A CLUSTER OF SEVERE THUNDERSTORMS IN CNTRL MO IS LOCATED ON A
WELL-DEFINED WARM FRONT EXTENDING EWD ACROSS CNTRL MO TO THE
NORTHEAST OF A 994 MB SFC LOW. THE STORMS ARE BEING SUPPORTED BY A
SUBTLE SHORTWAVE TROUGH EVIDENT IN WATER VAPOR IMAGERY MOVING
THROUGH SW MO. STRONG LIFT ASSOCIATED WITH THE SHORTWAVE TROUGH AND
ELEVATED INSTABILITY SHOULD SUPPORT STRONG CONVECTION ENEWD  ACROSS
SCNTRL IL EARLY THIS MORNING. FORECAST SOUNDINGS AROUND ST LOUIS AND
IN MT VERNON IL SHOW MUCAPE VALUES AROUND 1000 J/KG WITH EFFECTIVE
SHEAR OF 40 TO 50 KT. THIS COMBINED WITH MID-LEVEL LAPSE RATES
AROUND 7.5 C/KM SHOULD BE FAVORABLE FOR LARGE HAIL WITH THE MORE
INTENSE CORES. A WIND DAMAGE THREAT MAY ALSO EXIST BUT SHOULD BE
KEPT ISOLATED DUE TO A COOL STABLE BOUNDARY LAYER.

..BROYLES.. 03/02/2012

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

ATTN...WFO...LMK...IND...PAH...ILX...LSX...

LAT...LON   38929100 37959067 37928886 38268695 38948667 39678698
            39938787 39599044 38929100

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 2, 1:46 AM CSTMesoscale DiscussionSPCJackson, Monroe, Perry, Randolph, Saint Clair89 min
Mar 2, 2:07 AM CSTSevere Thunderstorm WatchSPCCalhoun, Jersey, Madison, Monroe, Randolph, Saint Clair5 hr
Mar 2, 5:52 AM CSTSevere Thunderstorm WatchSPCBond, Calhoun, Champaign, Christian, Clark, Clay and 29 more6 hr
Mar 2, 7:50 AM CSTMesoscale DiscussionSPCClark, Clay, Coles, Crawford, Cumberland, Douglas and 12 more85 min
Mar 2, 9:22 AM CSTMesoscale DiscussionSPCAlexander, Crawford, Edwards, Franklin, Gallatin, Hamilton and 13 more113 min
Mar 2, 9:54 AM CSTTornado Watch PDSSPCAlexander, Bond, Champaign, Christian, Clark, Clay and 41 more6 hr
Mar 2, 10:02 AM CSTMesoscale DiscussionSPCChampaign, Clark, Coles, Crawford, Cumberland, Douglas and 3 more88 min
Mar 2, 11:06 AM CSTMesoscale DiscussionSPCBoone, Carroll, Hancock, Henderson, Henry, Jo Daviess and 9 more4 hr
Mar 2, 12:05 PM CSTMesoscale DiscussionSPCGallatin, Hardin, Johnson, Massac, Pope, Saline and 2 more85 min
Mar 2, 3:40 AM CSTMesoscale DiscussionSPCCrawford, Dubois, Harrison, Perry, Pike, Spencer and 1 more65 min
Mar 2, 10:30 AM CSTMesoscale DiscussionSPCAdams, Blackford, Dearborn, Delaware, Fayette, Franklin and 7 more90 min
Mar 2, 12:02 PM CSTTornado Watch PDSSPCBartholomew, Brown, Clark, Crawford, Dearborn, Decatur and 25 more8 hr
Mar 2, 2:35 PM CSTMesoscale DiscussionSPCClark, Dearborn, Floyd, Franklin, Harrison, Jefferson and 4 more85 min
Mar 2, 10:28 AM CSTMesoscale DiscussionSPCDunklin, Pemiscot62 min

Nearby

Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Missouri, 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.