Under fairly zonal flow aloft, an inverted surface trough pushed toward the Ohio River Valley from the southwest. Enough moisture and lift were realized, as the surface low approached from the southwest, to produce up to 5 inches of snow and up to a half inch of ice accumulation across southern portions of central Indiana.
Every event with a place to put it; 9 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS IND wrote it up.
Under fairly zonal flow aloft, an inverted surface trough pushed toward the Ohio River Valley from the southwest. Enough moisture and lift were realized, as the surface low approached from the southwest, to produce up to 5 inches of snow and up to a half inch of ice accumulation across southern portions of central Indiana. Numerous accidents and slide-offs were reported during this winter weather episode, with a number of accident-related injuries. Multiple school and business closings were reported as well.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Indianapolis, IN wrote its last area forecast discussion before the first event at Dec 15, 6:10 PM EST, 2 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE INDIANAPOLIS IN 610 PM EST WED DEC 15 2010 .UPDATE... THE AVIATION SECTION HAS BEEN UPDATED BELOW. && .SYNOPSIS... A LOW PRESSURE SYSTEM WILL SLIDE ACROSS SOUTHERN KENTUCKY ON THURSDAY WHICH WILL BRING AN ACCUMULATING SNOW TO CENTRAL INDIANA TONIGHT AND THURSDAY POSSIBLY MIXING WITH SLEET OR FREEZING RAIN ACROSS SOUTH CENTRAL PARTS OF CENTRAL INDIANA. THEN...HIGH PRESSURE WILL GRADUALLY NOSE INTO THE OHIO VALLEY FROM THE PLAINS THIS WEEKEND ALLOWING FOR DRY BUT COLD WEATHER. A CLIPPER SYSTEM COULD BRING SOME LIGHT SNOW AMOUNTS TO CENTRAL INDIANA MONDAY AND MONDAY NIGHT...AND THEN FINALLY...EXPECT MAINLY DRY BUT CONTINUED COLD WEATHER TUESDAY AND WEDNESDAY AS HIGH PRESSURE AGAIN TAKES OVER. && .NEAR TERM /TONIGHT AND THURSDAY/... FORECAST FOCUS IS ON WINTER STORM. MODELS IN FAIR AGREEMENT. TO EXTENT THEY DIFFER USING NAM WHICH NORMALLY CAPTURES MESOSCALE FEATURES BEST IN SHORTER TERM. BOTH MODELS HAVE THE LEADING EDGE OF A STRONG EQUIVALENT POTENTIAL TEMPERATURE GRADIENT IN SOUTHERNCWA OVERNIGHT. SUCH AREAS FAVOR BANDS OF RELATIVELY HIGH PRECIPITATION. NAM NORMALLY BETTER WITH SUCH BANDS THAN GFS...AND I GENERALLY ACCEPT ITS QPF. THIS IN TURN IMPLIES STRONG UPWARD MOTION...GOOD COOLING OF COLUMN... AND ENHANCED DENDRITIC GROWTH. SO DECREASED CHANCE OF ANYTHING BUT SNOW...INCREASED SNOW TO LIQUID RATIOS. SOUNDINGS SUPPORT THE MOSTLY SNOW CONCEPT...BUT SLEET OR ZR NOT OUT OF QUESTION IN SOUTH. USING AN ABOVE CLIMATOLOGY SNOW RATIO OF 15 TO 1 GIVES 5 TO 7 INCHES OVERNIGHT IN SOUTH...JUSTIFYING WARNING THERE. STICKING WITH NAM QPF SNOW RAPIDLY DECREASES TO NORTH. CATEGORICAL POPS CENTRAL AND SOUTH OVERNIGHT. WITH CYCLONIC FLOW OVER ENTIRE AREA TONIGHT WILL BE AT LEAST LIKELY EVERYWHERE..WHICH MEANS SOME INCREASES TO GUIDANCE. WITH CONTINUED CYCLONIC FLOW LIKELY OVER EASTERN TWO THIRDS THURSDAY MORNING WITH AT LEAST A CHANCE IN THE WEST. MODEL TEMPS CLOSE TONIGHT FOR A SITUATION WITH PCPN DEVELOPING. DONT SEE OBVIOUS WAY TO IMPROVE THEM. COLDER MAV LOOKS BEST THURSDAY UNDER THICK CLOUD...COLD ADVECTION...AND NEW SNOW. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/... MAIN CHALLENGE TO THE SHORT TERM WILL BE CLOUD COVER AND TEMPERATURES AS MODELS DIFFER A DECENT AMOUNT ON THOSE TWO PARAMETERS. WEAK HIGH PRESSURE WILL GRADUALLY BUILD IN FROM THE PLAINS STARTING THURSDAY NIGHT WHICH SHOULD KEEP IT DRY. THE OPERATIONAL 12Z GFS AND 00Z ECMWF ALONG WITH THE 09Z SREF WERE AGREEING PRETTY GOOD ON MOISTURE AT THE VARIOUS LEVELS COMPARED TO THE 12Z NAM THROUGH THE PERIOD. SO...WILL STICK CLOSER TO THE MAJORITY AND KEEP IT MORE OR LESS CLOUDY UNTIL FRIDAY AFTERNOON WHEN THERE SHOULD BE SOME CLEARING FROM THE NORTHWEST. EVEN THEN...MODEL TIME SECTIONS WERE SHOWING INCREASED MOISTURE ABOVE 500 MILLIBARS WHICH WILL COINCIDE WITH INCREASING HIGH LEVEL CLOUDS AHEAD OF A BROAD UPPER TROUGH IN THE FAST QUASI-ZONAL FLOW. GFS MOS TEMPERATURES LOOK TOO LOW THURSDAY NIGHT WITH THE CLOUDS HOLDING AROUND. WITH THE DEGREE OF CLOUD COVER MORE UP IN THE AIR ON FRIDAY...LOOKS LIKE A COMPROMISE BETWEEN THE WARMER NAM AND COOLER GFS LOOKS GOOD. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... LONG RANGE MODELS IN GOOD AGREEMENT ON BRINGING QPF TO THE FORECAST AREA MONDAY AND MONDAY NIGHT AS A CLIPPER MOVES THROUGH. HOWEVER...THE 12Z GFS...GFS ENSEMBLES AND 00Z ECMWF ARE STILL OFF A BIT ON TIMING OF THE CLIPPER ITSELF ALONG WITH TIMING AND PLACEMENT OF THE QPF AND ALSO WHETHER THE SOUTHWEST WILL SEE SNOW OR RAIN. HOWEVER...BEING THAT FAR OUT...SMALL SNOW CHANCES STILL LOOK GOOD ACROSS THE ENTIRE FORECAST AND WILL HAVE TO FINE TUNE AS IT GETS CLOSER. FINALLY...HIGH PRESSURE WILL ONCE AGAIN SET IN BY TUESDAY WHICH SHOULD KEEP IT DRY BUT COLD THROUGH WEDNESDAY. && .AVIATION.../FOR 151800 TAF ISSUANCE/... FOCUS/IMPACT OF THIS TAF PACKAGE ON AVIATION WILL BE THE COMING SNOW EVENT. MODEL SOUNDINGS INDICATE SNOW THE MOST LIKELY PRECIP TYPE AT ALL SITES...BUT CANNOT ENTIRELY RULE OUT SOME MIXING OF SLEET OR FREEZING RAIN FOR A BRIEF PERIOD AT BMG...BUT WILL NOT HAVE IN THE TAF. OVERCAST VFR CEILINGS IN PLACE ACROSS THE AREA...AND THESE WILL DETERIORATE QUICKLY INTO MVFR IN THE HOUR OR TWO PRIOR TO SNOW ONSET AS THE ATMOSPHERE MOISTENS FROM ABOVE. EXPECT SNOW ONSET IN THE 05-08Z TIME FRAME ACROSS THE SITES...EARLIEST AT BMG...THEN HUF/IND...AND FINALLY AT LAF. GUIDANCE TYPICALLY STRUGGLES WITH VISIBILITIES AND CEILINGS IN SNOW...ALTHOUGH LAMP DOES A BIT BETTER...AND HAVE UNDERCUT SLIGHTLY TO PREVAILING 1 1/2SM AND OVC005...WITH A PERIOD OF LIFR 1SM OVC003 AT BMG WHERE SNOW WILL BE HEAVIEST. ALL SITES WILL HAVE THE POTENTIAL FOR AN OCCASIONAL DROP INTO LIFR CATEGORY...BUT IFR SHOULD BE THE PREVAILING. SNOW WILL LIGHTEN UP IN THE MID MORNING HOURS TOMORROW...ALTHOUGH SNOW GROWTH LAYER REMAINS SATURATED WITH DECENT LIFT UNTIL LATE AFTERNOON...AND HAVE CONTINUED 5SM -SN THROUGH 21-22Z. A GRADUAL IMPROVEMENT OF CEILINGS INTO THE MVFR CATEGORY WILL OCCUR AFTER SNOW ENDS. WINDS WILL REMAIN BELOW 10 KNOTS THROUGH THE PERIOD. && .IND WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST THURSDAY FOR INZ035>037-043>048-051>057. WINTER STORM WARNING FROM 7 PM THIS EVENING TO 1 PM EST THURSDAY FOR INZ060>065-067>072. && SYNOPSIS...MK NEAR TERM...JK SHORT TERM...MK LONG TERM....MK AVIATION...NIELD
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE INDIANAPOLIS IN 328 PM EST WED DEC 15 2010 INZ035>037-043>048-051>057-161100- FOUNTAIN-MONTGOMERY-BOONE-VERMILLION-PARKE-PUTNAM-HENDRICKS- MARION-HANCOCK-VIGO-CLAY-OWEN-MORGAN-JOHNSON-SHELBY-RUSH- 328 PM EST WED DEC 15 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA. .DAY ONE...TONIGHT. SNOW WILL DEVELOP TONIGHT. ACCUMULATIONS WILL RANGE FROM 2 TO 5 INCHES. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. PRECIPITATION MAINLY IN THE FORM OF LIGHT SNOW WILL DIMINISH BY MIDDAY THURSDAY. LITTLE TO NO ADDITIONAL ACCUMULATION IS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO PROVIDE SNOW AND ICE REPORTS TONIGHT AND THURSDAY MORNING. && MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL LOWERCASE) INZ060>065-067>072-161100- SULLIVAN-GREENE-MONROE-BROWN-BARTHOLOMEW-DECATUR-KNOX-DAVIESS- MARTIN-LAWRENCE-JACKSON-JENNINGS- 328 PM EST WED DEC 15 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA. .DAY ONE...THIS AFTERNOON AND TONIGHT. HEAVY SNOW IS EXPECTED TONIGHT. ACCUMULATIONS WILL BE 5 TO 7 INCHES. SOME SLEET OR FREEZING RAIN MIGHT OCCUR. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. A WINTRY MIX OF PRECIPITATION WILL DIMINISH BY MIDDAY THURSDAY. LITTLE TO NO ADDITIONAL SNOW OR ICE ACCUMULATION IS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO PROVIDE SNOW AND ICE REPORTS TONIGHT AND THURSDAY MORNING. && MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL LOWERCASE) INZ021-028>031-038>042-049-161100- CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-TIPTON-HAMILTON-MADISON- DELAWARE-RANDOLPH-HENRY- 328 PM EST WED DEC 15 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA. .DAY ONE...THIS AFTERNOON AND TONIGHT. SNOW WILL DEVELOP TONIGHT. ONE TO TWO INCHES OF ACCUMULATION ARE EXPECTED ACROSS THE REGION BY THURSDAY MORNING. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY. LIGHT SNOW WILL DIMINISH BY MIDDAY THURSDAY. LITTLE TO NO ADDITIONAL ACCUMULATION IS EXPECTED. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO PROVIDE SNOW REPORTS TONIGHT AND THURSDAY MORNING. && MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL LOWERCASE) KOCH
The national radar mosaic for the moment the first event began.
9 winter storm. Local standard time, as filed.
The Greene County EMA reported a tenth to two tenths of an inch of ice accumulation, with less than an inch of snowfall from this winter storm system. The county sheriff also reported about seven to eight vehicle slide-offs. Secondary roads were still ice and snow covered.
The Monroe County EMA reported a tenth of an inch of ice accumulation, with two to three inches of snowfall from this winter storm system.
A trained spotter in Brown County reported a tenth of an inch of ice accumulation, with three inches of snowfall from this winter storm system.
The Lawrence County EMA reported two to three tenths of an inch of ice accumulation, with one to two inches of snowfall from this winter storm system. One county highway truck was reported to have flipped on its side on Tunnelton Road. The driver and passenger sustained very minor injuries. Another highway truck got stuck trying to get to the accident. Many other accidents and slide-offs were reported.
The Jackson County EMA reported four tenths of an inch of ice accumulation, with three to four inches of snowfall from this winter storm system. All schools were reported closed and county roads were reported to be slick and hazardous.
The Sullivan County sheriff's office reported a tenth of an inch of ice accumulation, with less than an inch of snowfall from this winter storm system.
The Daviess County EMA reported one to three tenths of an inch of ice accumulation, with less than an inch of snowfall from this winter storm system. Numerous vehicle accidents were also reported, with all county schools closed.
A trained spotter in Martin County reported two to three tenths of an inch of ice accumulation, with one inch of snowfall from this winter storm system.
The Knox County EMA reported two tenths of an inch of ice accumulation, with less than an inch of snowfall from this winter storm system. Multiple vehicle slide-offs were also reported, with emergency vehicles and tow trucks becoming stuck responding to incidents. All schools were closed.
The Vincennes Sun-Commercial reported many area schools and businesses were closed and the Good Samaritan Hospital had 22 cases involving weather-related injuries during the course of the day on Thursday, December 16th. One of the injuries was considered critical, with four of them considered serious. Three minor fender-benders were also reported Thursday morning, but no major accidents.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Indiana in 2010Every state in 2010This day in weather historyWarnings in Indiana, December 2010
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 273314, 273315, 273317, 273327, 273342, 273310, 273325, 273328, 273321.