Alert archive / Illinois / Mesoscale Discussions in 2012
Mesoscale Discussion 270
The Storm Prediction Center issued this mesoscale discussion at Mar 18, 2012, 1:41 AM CDT for 47 counties in Illinois. It was in force for 94 min.
The area
The outline as issued.
The facts
- Issued
- Mar 18, 2012, 1:41 AM CDT (06:41 UTC)
- Expired
- Mar 18, 2012, 3:15 AM CDT
- In force
- 94 min
- Issued by
- the Storm Prediction Center
All 47 counties
Bond County, IL, Bureau County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton 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, Ford County, IL, Fulton County, IL, Henry County, IL, Jasper County, IL, Knox County, IL, Lawrence County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Macoupin County, IL, Marion County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Putnam County, IL, Richland County, IL, Sangamon County, IL, Schuyler County, IL, Shelby County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Wayne County, IL, Woodford County, IL
The radar
The Lincoln radar (KILX), 11 km from the middle of the area, began a volume at 06:44 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 00:00Z, 6.7 hours before the alert went out and 60 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1443 m above ground
- 0-6 km bulk shear
- 13 kt
- 0-1 km storm-relative helicity
- -27 m²/s²
- 0-3 km storm-relative helicity
- 26 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
987
ACUS11 KWNS 180641
SWOMCD
SPC MCD 180641
INZ000-ILZ000-180815-
MESOSCALE DISCUSSION 0270
NWS STORM PREDICTION CENTER NORMAN OK
0141 AM CDT SUN MAR 18 2012
AREAS AFFECTED...IL...IN
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 180641Z - 180815Z
THE BAND OF ONGOING STORMS...EAST OF THE BURLINGTON IA/QUINCY IL AND
ST. LOUIS MO AREAS...APPEARS TO BE SUPPORTED BY A ZONE OF ENHANCED
LOWER/MID TROPOSPHERIC WARM ADVECTION...IN THE WAKE OF A WEAK
MID-LEVEL CIRCULATION AND ASSOCIATED TROUGH SLOWLY TURNING EASTWARD
ACROSS ILLINOIS/INDIANA. THIS IS ALSO ON THE EASTERN PERIPHERY OF
WARM ELEVATED MIXED LAYER AIR...WHICH HAS OVERSPREAD MOST AREAS EAST
OF THE ROCKIES INTO THE VICINITY OF THE MISSISSIPPI RIVER...WHERE
STEEP MID-LEVEL LAPSE RATES ARE CONTRIBUTING MODERATELY LARGE MOST
UNSTABLE CAPE. DESPITE THE LACK OF STRONGER VERTICAL
SHEAR...THERMODYNAMIC PROFILES HAVE BEEN SUFFICIENT TO SUPPORT
OCCASIONAL MARGINALLY SEVERE HAIL IN STRONGER UPDRAFT PULSES...AND
LIKELY WILL REMAIN SO AS LONG AS ACTIVITY PERSISTS. IT APPEARS THAT
THIS COULD BE ANOTHER COUPLE OF HOURS...AT LEAST INTO THE 09-10Z
TIME FRAME...PERHAPS LONGER...WITH A GRADUAL EASTWARD DEVELOPMENT
TOWARD THE INDIANA/ILLINOIS BORDER AREA. BUT A SUBSTANTIVE INCREASE
IN INTENSITY AND ORGANIZATION...BEYOND WHAT IS OCCURRING NOW...IS
NOT ANTICIPATED.
..KERR.. 03/18/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IND...PAH...LOT...ILX...LSX...DVN...
LAT...LON 41009076 41379039 41548954 41228887 40798819 39608745
38838758 38278832 38428918 38728971 39969074 41009076Nearby
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.