Alert archive / Indiana / Mesoscale Discussions in 2012
Mesoscale Discussion 2233
The Storm Prediction Center issued this mesoscale discussion at Dec 26, 2012, 10:39 AM EST for 32 counties in Indiana; 27 counties in Ohio. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 26, 2012, 10:39 AM EST (15:39 UTC)
- Expired
- Dec 26, 2012, 4:45 PM EST
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
All 59 counties
Adams County, IN, Allen County, IN, Blackford County, IN, Boone County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Delaware County, IN, Fayette County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jay County, IN, Johnson County, IN, Kosciusko County, IN, Madison County, IN, Marion County, IN, Miami County, IN, Noble County, IN, Randolph County, IN, Rush County, IN, Shelby County, IN, Tipton County, IN, Union County, IN, Wabash County, IN, Wayne County, IN, Wells County, IN, Whitley County, IN, Allen County, OH, Auglaize County, OH, Champaign County, OH, Crawford County, OH, Darke County, OH, Defiance County, OH, Fulton County, OH, Hancock County, OH, Hardin County, OH, Henry County, OH, Huron County, OH, Logan County, OH, Marion County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Paulding County, OH, Preble County, OH, Putnam County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Shelby County, OH, Van Wert County, OH, Williams County, OH, Wood County, OH, Wyandot County, OH
The radar
The Northern Indiana radar (KIWX), 136 km from the middle of the area, began a volume at 15:37 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
Detroit, MI (KDTX), launched 12:00Z, 3.7 hours before the alert went out and 236 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
- 660 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 79 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
079
ACUS11 KWNS 261540
SWOMCD
SPC MCD 261539
OHZ000-INZ000-262145-
MESOSCALE DISCUSSION 2233
NWS STORM PREDICTION CENTER NORMAN OK
0939 AM CST WED DEC 26 2012
AREAS AFFECTED...CNTRL/NRN INDIANA...W-CNTRL/NWRN/N-CNTRL OH
CONCERNING...BLIZZARD
VALID 261539Z - 262145Z
SUMMARY...THE THREAT FOR BLIZZARD CONDITIONS WILL EXPAND NEWD FROM
CNTRL INDIANA/W-CNTRL OH INTO NWRN/N-CNTRL OH. THESE CONDITIONS WILL
LIKELY CONTINUE THROUGH THE AFTERNOON.
DISCUSSION...WATER VAPOR IMAGERY DEPICTS A LARGE EXTRATROPICAL
CYCLONE IN ITS MATURE STAGE OVER THE ERN CONUS. A WELL-DEFINED WARM
CONVEYOR BELT ASSOCIATED WITH AMPLE WARM ADVECTION AROUND THE
ERN/NRN SEMICIRCLES OF THE DEEP CYCLONE WILL CONTINUE TO SUPPORT A
NEWD EXPANSION OF HEAVY SNOW FROM CNTRL INDIANA/W-CNTRL OH INTO
NWRN/N-CNTRL OH INTO THIS AFTERNOON. THE STRENGTH OF ISENTROPIC
ASCENT WILL BE AUGMENTED BY A MODEST CONVECTIVE ENHANCEMENT OWING TO
NARROW ELEVATED CAPE LAYERS TO SUPPORT HEAVY SNOW WITH RATES OF
1-1.5 IN/HR. OBSERVATIONS ACROSS W-CNTRL OH INDICATE THIS
INSTABILITY BEING MANIFESTED AS THUNDERSNOW...AND A LIGHTNING STRIKE
OR TWO MAY ACCOMPANY THE MOST INTENSE SNOW RATES INTO THE AFTERNOON.
STRONG LOW-LEVEL FLOW ACCOMPANYING THE COLD CONVEYOR BELT ATTENDANT
TO THE CYCLONE WILL SUPPORT 30-40 KT MEAN FLOW IN THE 0-1-KM LAYER
PER FORECAST SOUNDINGS. RELATIVELY STEEP LAPSE RATES IN THE LOWEST
KILOMETER AGL WILL SUPPORT 20-30 MPH WINDS AND FREQUENT GUSTS OF
30-40 MPH. THE STRONGEST OF THESE WINDS WILL LIE WITHIN A CORRIDOR
FROM CNTRL INDIANA INTO NWRN OH WHERE THE TIGHTEST SFC PRESSURE
GRADIENT IS EXPECTED TO EXIST. THESE WINDS WILL COMBINE WITH THE
SNOW TO CREATE WHITEOUT CONDITIONS AND A BLIZZARD THREAT.
OBSERVATIONS ACROSS CNTRL IND SUGGEST VISIBILITIES OF ONE-QUARTER
MILE WITH HEAVY SNOW...AND SIMILAR CONDITIONS WILL LIKELY AFFECT THE
DISCUSSION AREA INTO THE AFTERNOON.
..COHEN.. 12/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CLE...ILN...IWX...IND...
LAT...LON 41278224 40758251 40548311 39998396 39588449 39428594
39688648 40118666 40918632 41548550 41678466 41658364
41478280 41278224SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 26, 3:25 AM EST | Mesoscale Discussion | SPC | Bartholomew, Boone, Brown, Clark, Clay, Crawford and 45 more | 6 hr |
| Dec 26, 3:29 PM EST | Mesoscale Discussion | SPC | Elkhart, LaGrange, Saint Joseph, Steuben | 3 hr |
| Dec 26, 6:46 AM EST | Mesoscale Discussion | SPC | Athens, Washington | 4 hr |
| Dec 26, 9:57 AM EST | Mesoscale Discussion | SPC | Coshocton, Delaware, Fairfield, Fayette, Franklin, Guernsey and 8 more | 5 hr |
| Dec 26, 11:40 AM EST | Mesoscale Discussion | SPC | Ashland, Carroll, Columbiana, Geauga, Holmes, Mahoning and 8 more | 6 hr |
Nearby
Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Ohio, 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.