Alert archive / Indiana / Mesoscale Discussions in 2012
Mesoscale Discussion 2194
The Storm Prediction Center issued this mesoscale discussion at Dec 20, 2012, 1:10 PM EST for 22 counties in Indiana. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 20, 2012, 1:10 PM EST (18:10 UTC)
- Expired
- Dec 20, 2012, 3:15 PM EST
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 22 counties
Bartholomew County, IN, Boone County, IN, Brown County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Howard County, IN, Johnson County, IN, Madison County, IN, Marion County, IN, Monroe County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Putnam County, IN, Shelby County, IN, Tippecanoe County, IN, Tipton County, IN
The radar
The Indianapolis radar (KIND), 5 km from the middle of the area, began a volume at 18:12 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, 6.2 hours before the alert went out and 200 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
- 586 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 180 m²/s²
- 0-3 km storm-relative helicity
- 49 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
995
ACUS11 KWNS 201810
SWOMCD
SPC MCD 201810
INZ000-202015-
MESOSCALE DISCUSSION 2194
NWS STORM PREDICTION CENTER NORMAN OK
1210 PM CST THU DEC 20 2012
AREAS AFFECTED...CNTRL IND
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 201810Z - 202015Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...AN ISOLATED SVR WIND THREAT MAY OCCUR THIS AFTERNOON. THE
ISSUANCE OF A WW IS UNLIKELY.
DISCUSSION...A STRONG COLD FRONT WILL TRACK ENEWD ACROSS PARTS OF
CNTRL IND THIS AFTERNOON WHILE A SFC LOW SHIFTS NEWD TOWARD CHICAGO.
A NARROW CORRIDOR OF SFC HEATING OWING TO POCKETS OF INSOLATION
AMIDST UPPER 40S SFC DEWPOINTS IN ADVANCE OF THE FRONT IS SUPPORTING
VERY MARGINAL INSTABILITY WITH MLCAPE VALUES OF 50-100 J/KG.
HOWEVER...GIVEN THE STRONG SFC-LAYER CONFLUENCE ALONG THE FRONT...A
LINE OF LOW-TOPPED CONVECTION WILL TRACK EWD/ENEWD ACROSS CNTRL
IND...REACHING THE INDIANAPOLIS AREA BETWEEN 1830Z AND 1930Z.
DOWNWARD MOMENTUM TRANSPORT IN THE STRONGEST CONVECTION MAY SUPPORT
AN ISOLATED SVR WIND GUST OR TWO GIVEN 50 KT OF 1-KM-AGL SLY FLOW
PER INDIANAPOLIS VWP DATA. THESE DATA ALSO INDICATE 35-40 KT OF
0-1-KM BULK SHEAR WITH MODEST DIRECTIONAL SHEAR IN THE LOW
LEVELS...AND THE DEVELOPMENT OF A TORNADO CANNOT BE RULED OUT.
REGARDLESS...LIMITED BUOYANCY WILL PRECLUDE THE DEVELOPMENT OF A
MORE SUBSTANTIAL SVR THREAT OWING TO COLDER MID-LEVEL TEMPERATURES
BEING REMOVED WELL TO THE W OF THE REGION.
..COHEN/CORFIDI.. 12/20/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IWX...IND...
LAT...LON 38868660 39198684 39788693 40458704 40758684 40798630
40638572 40248543 39378552 39068588 38918609 38868660Nearby
Mesoscale Discussions in Indiana, 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.