Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 2227

December 26, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Dec 26, 2012, 2:25 AM CST for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Dec 26, 2012, 2:25 AM CST (08:25 UTC)
Expired: Dec 26, 2012, 8:30 AM CST
In force: 6 hr
Issued by: the Storm Prediction Center

All 101 counties

Alexander County, IL, Clark County, IL, Clay County, IL, Crawford County, IL, Edwards County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Johnson County, IL, Lawrence County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Union County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Williamson County, IL, Bartholomew County, IN, Boone County, IN, Brown County, IN, Clark County, IN, Clay County, IN, Crawford County, IN, Daviess County, IN, Dearborn County, IN, Decatur County, IN, Delaware County, IN, Dubois County, IN, Fayette County, IN, Franklin County, IN, Gibson County, IN, Greene County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Jackson County, IN, Jay County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Madison County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Morgan County, IN, Ohio County, IN, Orange County, IN, Owen County, IN, Perry County, IN, Pike County, IN, Posey County, IN, Putnam County, IN, Randolph County, IN, Ripley County, IN, Rush County, IN, Scott County, IN, Shelby County, IN, Spencer County, IN, Sullivan County, IN, Union County, IN, Vanderburgh County, IN, Vigo County, IN, Warrick County, IN, Washington County, IN, Wayne County, IN, Ballard County, KY, Caldwell County, KY, Carlisle County, KY, Crittenden County, KY, Daviess County, KY, Henderson County, KY, Livingston County, KY, Lyon County, KY, McCracken County, KY, Union County, KY, Webster County, KY, Auglaize County, OH, Butler County, OH, Champaign County, OH, Clark County, OH, Darke County, OH, Greene County, OH, Hamilton County, OH, Logan County, OH, Mercer County, OH, Miami County, OH, Montgomery County, OH, Preble County, OH, Shelby County, OH, Union County, OH, Warren County, OH

The radar

The Louisville radar (KLVX), 96 km from the middle of the area, began a volume at 08:27 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, 8.4 hours before the alert went out and 238 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 659 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: 50 m²/s²
0-3 km storm-relative helicity: 105 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.

777 
ACUS11 KWNS 260825
SWOMCD
SPC MCD 260825 
OHZ000-KYZ000-INZ000-ILZ000-MOZ000-261430-

MESOSCALE DISCUSSION 2227
NWS STORM PREDICTION CENTER NORMAN OK
0225 AM CST WED DEC 26 2012

AREAS AFFECTED...SRN IL...CNTRL AND SRN IND...W-CNTRL AND SW OH

CONCERNING...BLIZZARD 

VALID 260825Z - 261430Z

SUMMARY...HEAVY SNOW AND BLIZZARD CONDITIONS WILL SPREAD NEWD FROM
SE MO/SRN IL ACROSS CNTRL IND INTO W-CNTRL AND SW OH EARLY THIS
MORNING. SNOWFALL RATES AROUND 1-1.5 INCHES PER HOUR ARE POSSIBLE AT
TIMES. NORTH WINDS AROUND 20-30 MPH WITH HIGHER GUSTS WILL LEAD TO
WHITEOUT CONDITIONS.

DISCUSSION...STRONG PVA WAS PIVOTING E/NE ACROSS WRN TN INTO SRN KY
AS OF 0730Z...PROVIDING MOIST ASCENT OVER BAND OF 700 MB
FRONTOGENESIS FROM SRN IL EWD ACROSS CNTRL KY. AS THE SFC LOW
/CENTERED OVER S-CNTRL TN AT 08Z/ CONTINUES TO LIFT N/NE...WARM
CONVEYOR BELT PROCESSES WILL CONTINUE TO PROVIDE FUEL FOR HEAVY
SNOW. THE HEAVIEST SNOW WAS MOVING ACROSS SE MO INTO SW IL AND WILL
CONTINUE TO DEVELOP NEWD TOWARD CENTRAL IND AND SW/S-CNTRL OH OVER
THE NEXT SEVERAL HOURS. SNOWFALL RATES APPROACHING 1-1.5 INCHES AN
HOUR ARE POSSIBLE. BRIEF PERIODS OF EVEN HEAVIER SNOW MAY ACCOMPANY
SMALLER CONVECTIVE BANDS ACROSS SRN IL...BUT INCREASINGLY
UNFAVORABLE MIDLEVEL LAPSE RATES WILL LIMIT CONVECTIVE POTENTIAL
ACROSS IND AND OH. ADDITIONALLY...SOME FREEZING RAIN AND SLEET MAY
INITIALLY MIX WITH SNOW ACROSS SOUTHERN PORTIONS OF THE MCD AREA AS
THE TRANSITION FROM LIQUID TO FROZEN PRECIPITATION OCCURS. 

NLY SFC WINDS WILL INCREASE ON THE BACK SIDE OF THE LOW /AS EVIDENT
IN SFC OBS FROM NE ARK INTO SRN IL/. SUSTAINED WINDS AROUND 20-30
MPH WITH HIGHER GUSTS ARE POSSIBLE. IN FACT...A GUST TO 42 MPH WAS
OBSERVED AT POPLAR BLUFF WAS AT 0745Z. THESE STRONG WINDS COMBINED
WITH HEAVY SNOW WILL LEAD TO BLIZZARD CONDITIONS SPREADING NEWD
THROUGH EARLY MORNING.

..LEITMAN.. 12/26/2012

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

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

LAT...LON   36958816 36828852 36828911 37018942 37398960 37728965
            38418911 39468767 40048654 40408545 40598431 40538366
            40358338 40108330 39808352 39508388 38878496 38148634
            37718702 36958816

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 25, 8:00 PM CST	Mesoscale Discussion	SPC	Alexander, Johnson, Massac, Pope, Pulaski, Union	6 hr
Dec 26, 9:39 AM CST	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Cass, Clinton and 26 more	6 hr
Dec 26, 2:29 PM CST	Mesoscale Discussion	SPC	Elkhart, LaGrange, Saint Joseph, Steuben	3 hr
Dec 26, 5:46 AM CST	Mesoscale Discussion	SPC	Athens, Washington	4 hr
Dec 26, 8:57 AM CST	Mesoscale Discussion	SPC	Coshocton, Delaware, Fairfield, Fayette, Franklin, Guernsey and 8 more	5 hr
Dec 26, 10:40 AM CST	Mesoscale Discussion	SPC	Ashland, Carroll, Columbiana, Geauga, Holmes, Mahoning and 8 more	6 hr

Nearby

Mesoscale Discussions in Indiana, 2012 Mesoscale Discussions in Illinois, 2012 Mesoscale Discussions in Ohio, 2012 Every 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.