August 13, 2011 Central Indiana Severe Weather

8pm surface map
Surface Map and Radar Image at 8:00 PM EDT August 13

(The Indiana State Climate Office has also created a review of this event with addtional data)

Thunderstorms developed ahead of a cold front during the afternoon and evening of August 13. As these storms moved across central Indiana, they brought damaging winds and large hail to the area. The storms also caused part of a stage to collapse at the Indiana State Fair, resulting in fatalities. A list of severe weather reports can be found near the bottom of this page.

The threat for severe weather was first acknowledged in the Hazardous Weather Outlook (HWO) issued by the NWS Indianapolis on Thursday the 11th and continued to mention the threats in the HWOs through Saturday the 13th. The Storm Prediction Center placed central Indiana in a Slight Risk of severe weather for their Day 2 Outlook on Friday the 12th, and kept the area in a Slight Risk for the Day 1 Outlook on Saturday the 13th. By the 1230 PM EDT update, the Storm Prediction Center highlighted central Indiana for an increased potential for damaging winds (Click an image to enlarge):


SPC Day 1 Convective Outlook from 2:00 AM EDT August 13	SPC Day 1 Damaging Wind Outlook, from 12:30 PM EDT August 13

Hazardous Weather Outlook Issued by NWS Indianapolis at 4:25 AM EDT August 13:

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
425 AM EDT SAT AUG 13 2011

INZ021-028>031-035>049-051>057-060>065-067>072-141000-
CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-FOUNTAIN-MONTGOMERY-
BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-RANDOLPH-VERMILLION-PARKE-
PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-VIGO-CLAY-OWEN-MORGAN-
JOHNSON-SHELBY-RUSH-SULLIVAN-GREENE-MONROE-BROWN-BARTHOLOMEW-
DECATUR-KNOX-DAVIESS-MARTIN-LAWRENCE-JACKSON-JENNINGS-
425 AM EDT SAT AUG 13 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED ESPECIALLY THIS AFTERNOON AND
EVENING. THUNDERSTORMS MAY BE SEVERE WITH DAMAGING WINDS AND LARGE
HAIL AS THE MAIN THREATS. STORMS WILL ALSO PRODUCE DANGEROUS
LIGHTNING AND BRIEF HEAVY RAINFALL. AN ISOLATED TORNADO IS ALSO
POSSIBLE. THUNDERSTORMS WILL BE MOST NUMEROUS ACROSS CENTRAL
INDIANA BETWEEN 4 PM AND MIDNIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

A FEW THUNDERSTORMS ARE POSSIBLE SUNDAY AND AGAIN WEDNESDAY AND
THURSDAY. SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. HOWEVER
THUNDERSTORMS MAY PRODUCE GUSTY WINDS...SMALL HAIL...DANGEROUS LIGHTNING
AND BRIEF HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE SATURDAY AFTERNOON AND EVENING.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

$$

Hazardous Weather Outlook Issued by NWS Indianapolis at 4:45 PM EDT August 13:

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
445 PM EDT SAT AUG 13 2011

INZ021-028>031-035>049-051>057-060>065-067>072-142045-
CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-FOUNTAIN-MONTGOMERY-
BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-RANDOLPH-VERMILLION-PARKE-
PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-VIGO-CLAY-OWEN-MORGAN-
JOHNSON-SHELBY-RUSH-SULLIVAN-GREENE-MONROE-BROWN-BARTHOLOMEW-
DECATUR-KNOX-DAVIESS-MARTIN-LAWRENCE-JACKSON-JENNINGS-
445 PM EDT SAT AUG 13 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TONIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED TO MOVE SOUTHEAST ACROSS
CENTRAL INDIANA THROUGH THIS EVENING. THUNDERSTORMS MAY BE SEVERE
WITH DAMAGING WINDS AND LARGE HAIL AS THE MAIN THREATS. THE STORMS
WILL ALSO PRODUCE DANGEROUS LIGHTNING AND BRIEF HEAVY RAINFALL. AN
ISOLATED TORNADO IS ALSO POSSIBLE. THUNDERSTORMS WILL BE MOST
NUMEROUS ACROSS CENTRAL INDIANA BETWEEN 6 PM AND MIDNIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY.

A FEW THUNDERSTORMS ARE POSSIBLE SUNDAY AND AGAIN WEDNESDAY AND
THURSDAY. SEVERE WEATHER IS NOT ANTICIPATED AT THIS TIME. HOWEVER
THUNDERSTORMS MAY PRODUCE GUSTY WINDS...SMALL HAIL...DANGEROUS LIGHTNING
AND BRIEF HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN WITH REPORTS THROUGH THIS
EVENING AND TONIGHT.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

$$

Thunderstorms developed across central Indiana during the afternoon into the early evening, with the first severe weather reports coming after 7:00 PM. Please note that in all radar images below the weakest echoes have been removed to help viewing of some features.


Radar image overview from near 8:00 PM EDT - Click to Enlarge	Radar image overview from near 9:00 PM EDT - Click to Enlarge

Above are radar images of central Indiana at just past 8:00 PM and again just past 9:00 PM, giving an overview of the storms. Click any image to enlarge.

Here is a closer look at the storms which caused the tragedy at the Indiana State Fair. First up is a radar image from 8:12 PM EDT:


Radar Image at 8:12 PM - Click to Enlarge	Same image, but with a line showing where the first outflow boundary existed at the time

Next is a reflectivity image from 8:21 PM:

Radar Image at 8:21 PM, Click to enlarge

Radar image from 8:21 PM - Click to enlarge

By 8:26 PM, some of the initial storms began to die, pushing out cold air ahead of them. This helped initiate new storms as well as a second outflow boundary:


Radar image from 8:26 PM - Click to enlarge	Annotated version of the same image. Click to enlarge.

Next is a radar image from 8:30 PM EDT:

Radar image from 8:30 PM EDT - Click to enlarge

Radar image at 8:30 PM EDT - Click to enlarge

The storms prompted a severe thunderstorm warning, which included all of Marion County among others, at 8:39 PM EDT.
As the storms continued to develop, an inflow notch developed in the line of storms, creating a bowing structure to the line of storms as the strong wind pushed out from the storm:


Radar Image at 8:39 PM EDT - Click to enlarge	Annotated version of the same image. Click to enlarge.

Radar velocity image at 8:39 PM EDT - Click to enlarge


Radar image at 8:44 PM EDT - Click to enlarge	Radar velocity image at 8:44 PM EDT - Click to enlarge

Radar image at 8:48 PM EDT - Click to enlarge

Damaging wind gusts of 70 mph were recorded at Speedway in Marion County, 77 mph at Plainfield in eastern Hendricks County, 51 mph at the Indianapolis International Airport, and 60 mph at Fortville in western Hancock County at 8:49 p.m., 8:50 p.m. 8:56 p.m., and 9:08 p.m., respectively. The storms continued across the remainder of the Indianapolis metropolitan area through 9:30 p.m, producing additional wind damage and large hail.

Below is a list of all reports received for the event. Note that these reports are considered preliminary until certified by the National Climatic Data Center (NCDC):

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1032 AM EDT MON AUG 15 2011

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0714 PM     HAIL             8 NW LAFAYETTE          40.49N 86.98W
08/13/2011  M1.00 INCH       TIPPECANOE         IN   AMATEUR RADIO

0720 PM     HAIL             5 SE OTTERBEIN          40.44N 87.03W
08/13/2011  E0.75 INCH       TIPPECANOE         IN   TRAINED SPOTTER

0723 PM     HAIL             3 WNW WEST LAFAYETTE    40.46N 86.96W
08/13/2011  E0.25 INCH       TIPPECANOE         IN   AMATEUR RADIO

0725 PM     HAIL             5 NW LAFAYETTE          40.47N 86.94W
08/13/2011  E0.75 INCH       TIPPECANOE         IN   TRAINED SPOTTER

0725 PM     TSTM WND GST     4 WSW CLARKS HILL       40.22N 86.79W
08/13/2011  E60.00 MPH       TIPPECANOE         IN   BROADCAST MEDIA

0725 PM     HAIL             WEST LAFAYETTE          40.44N 86.91W
08/13/2011  M0.75 INCH       TIPPECANOE         IN   AMATEUR RADIO

0725 PM     HAIL             3 NW WEST LAFAYETTE     40.48N 86.95W
08/13/2011  E0.50 INCH       TIPPECANOE         IN   AMATEUR RADIO

0727 PM     TSTM WND GST     LAFAYETTE               40.41N 86.87W
08/13/2011  E50.00 MPH       TIPPECANOE         IN   TRAINED SPOTTER

0727 PM     HAIL             WEST LAFAYETTE          40.44N 86.91W
08/13/2011  E0.75 INCH       TIPPECANOE         IN   TRAINED SPOTTER

0728 PM     TSTM WND DMG     BATTLE GROUND           40.51N 86.84W
08/13/2011                   TIPPECANOE         IN   EMERGENCY MNGR

            TREES DOWN...NO SIZE AVAILABLE

0729 PM     TSTM WND GST     LAFAYETTE               40.41N 86.87W
08/13/2011  M59.00 MPH       TIPPECANOE         IN   ASOS

0730 PM     HAIL             1 S LAFAYETTE           40.40N 86.87W
08/13/2011  U1.00 INCH       TIPPECANOE         IN   EMERGENCY MNGR

0730 PM     TSTM WND DMG     WEST LAFAYETTE          40.44N 86.91W
08/13/2011                   TIPPECANOE         IN   TRAINED SPOTTER

            MULTIPLE TREES DOWN 3-4 INCHES IN DIAMETER

0731 PM     TSTM WND DMG     BATTLE GROUND           40.51N 86.84W
08/13/2011                   TIPPECANOE         IN   TRAINED SPOTTER

            SEVERAL TREES DOWN. PEA SIZED HAIL. ESTIMATED WINDS OF 60
            MPH.

0732 PM     HAIL             WEST LAFAYETTE          40.44N 86.91W
08/13/2011  M0.75 INCH       TIPPECANOE         IN   AMATEUR RADIO

0734 PM     HAIL             LAFAYETTE               40.41N 86.87W
08/13/2011  M0.75 INCH       TIPPECANOE         IN   AMATEUR RADIO

0734 PM     HAIL             LAFAYETTE               40.41N 86.87W
08/13/2011  E0.50 INCH       TIPPECANOE         IN   TRAINED SPOTTER

0737 PM     HAIL             DAYTON                  40.38N 86.78W
08/13/2011  U1.75 INCH       TIPPECANOE         IN   EMERGENCY MNGR

0741 PM     HAIL             DAYTON                  40.38N 86.78W
08/13/2011  M0.50 INCH       TIPPECANOE         IN   AMATEUR RADIO

            INTERSTATE 65 OVERPASS AND 200 SOUTH

0750 PM     HAIL             1 W CLINTON             39.66N 87.42W
08/13/2011  E0.75 INCH       VERMILLION         IN   AMATEUR RADIO

            ACCOMPANIED BY ESTIMATED 45 MPH WINDS...LOCATED AT STATE
            ROUTE 63 AND STATE ROUTE 163

0801 PM     HAIL             MULBERRY                40.35N 86.67W
08/13/2011  U0.25 INCH       CLINTON            IN   TRAINED SPOTTER

0813 PM     HAIL             1 W CLINTON             39.66N 87.42W
08/13/2011  U0.25 INCH       VERMILLION         IN   AMATEUR RADIO

            ESTIMATED WINDS OF 55 MPH ACCOMPANIED THE HAIL...LOCATED
            AT STATE ROUTES 163 AND 63.

0813 PM     TSTM WND GST     1 W CLINTON             39.66N 87.42W
08/13/2011  E55.00 MPH       VERMILLION         IN   AMATEUR RADIO

            ACCOMPANIED BY PEA SIZE HAIL

0813 PM     TSTM WND GST     1 W CLINTON             39.66N 87.42W
08/13/2011  E55.00 MPH       VERMILLION         IN   AMATEUR RADIO

            ACCOMPANIED BY PEA SIZE HAIL...LOCATED AT STATE ROUTES
            163 AND 63

0815 PM     TSTM WND GST     5 NE KOKOMO             40.53N 86.07W
08/13/2011  M54.00 MPH       HOWARD             IN   AWOS

0835 PM     HAIL             LIZTON                  39.89N 86.54W
08/13/2011  U0.50 INCH       HENDRICKS          IN   EMERGENCY MNGR

0845 PM     TSTM WND DMG     7 WNW INDIANAPOLIS      39.82N 86.27W
08/13/2011                   MARION             IN   PUBLIC

            MULTIPLE TREES AND TREE LIMBS REPORTED DOWN IN A SMALL...
            CONFINED AREA

0849 PM     TSTM WND GST     SPEEDWAY                39.79N 86.25W
08/13/2011  M70.00 MPH       MARION             IN   PUBLIC

            REPORTED BY LONG-TIME TELEVISION WEATHER SPOTTER. A LARGE
            100-YEAR OLD TREE WAS BLOWN DOWN. POWER IS OUT IN
            NEIGHBORHOOD.

0849 PM     TSTM WND DMG     INDIANA STATE FAIRGROUN 39.83N 86.13W
08/13/2011                   MARION             IN   NWS EMPLOYEE

            *** 5 FATAL, 45 INJ *** STAGE COLLAPSE DURING
            CONCERT...MANY INJURIES...CORONER ON SCENE...WINDS
            ESTIMATED BETWEEN 60 AND 70 MPH. MULTIPLE SOURCES USED
            FOR THIS REPORT. INDIANAPOLIS POLICE CHIEF PROVIDED TIME.
            FATALITY AND INJURY NUMBERS UPDATED AS NEW INFORMATION IS
            RECEIVED.

0849 PM     TSTM WND DMG     SPEEDWAY                39.79N 86.25W
08/13/2011                   MARION             IN   PUBLIC

            A LARGE 100-YEAR OLD TREE WAS BLOWN DOWN AND POWER
            KNOCKED OUT FROM A MEASURED 70 MPH WIND GUST. REPORTED BY
            LONG-TIME TELEVISION WEATHER SPOTTER.

0850 PM     TSTM WND GST     PLAINFIELD              39.70N 86.39W
08/13/2011  M77.00 MPH       HENDRICKS          IN   AMATEUR RADIO

            LOCATED AT US 40 AND CENTER STREET

0908 PM     TSTM WND GST     FORTVILLE               39.94N 85.85W
08/13/2011  E60.00 MPH       HANCOCK            IN   TRAINED SPOTTER

0908 PM     HAIL             ANDERSON                40.09N 85.69W
08/13/2011  E0.50 INCH       MADISON            IN   TRAINED SPOTTER

0913 PM     HAIL             1 N PENDLETON           40.01N 85.74W
08/13/2011  E1.50 INCH       MADISON            IN   PUBLIC

0925 PM     TSTM WND GST     3 ESE MUNCIE            40.18N 85.35W
08/13/2011  E65.00 MPH       DELAWARE           IN   PUBLIC

            SMALL BRANCHES DOWN AND POWER FLASHES IN THE DISTANCE...A
            BRIEF WHIRL WIND OF SOME SORT

0945 PM     TSTM WND DMG     NEW CASTLE              39.92N 85.36W
08/13/2011                   HENRY              IN   AMATEUR RADIO

            4-INCH DIAMETER TREE LIMB DOWN...ACCOMPANIED BY 50 MPH
            WINDS

0950 PM     FLOOD            MUNCIE                  40.20N 85.39W
08/13/2011                   DELAWARE           IN   AMATEUR RADIO

            LARGE STRETCH OF 29TH STREET FLOODED BETWEEN
            APPROXIMATELY MADISON AND MEMORIAL. RAINFALL FROM 915 TO
            10 PM MEASURED 0.98 INCHES.

1003 PM     HEAVY RAIN       3 SE MUNCIE             40.17N 85.34W
08/13/2011  M0.98 INCH       DELAWARE           IN   AMATEUR RADIO

            RAINFALL FROM 915 TO 10 PM EDT

1057 PM     HAIL             BLOOMINGTON             39.17N 86.52W
08/13/2011  E0.50 INCH       MONROE             IN   AMATEUR RADIO

            DIME SIZE HAIL AT CURRY PIKE AND WOODYARD ROAD

1058 PM     HAIL             2 W BLOOMINGTON         39.17N 86.56W
08/13/2011  U1.00 INCH       MONROE             IN   AMATEUR RADIO

            LOCATED NEAR STATE ROAD 48 AND HARSTRAIT

1105 PM     TSTM WND GST     BLOOMINGTON             39.17N 86.52W
08/13/2011  E60.00 MPH       MONROE             IN   TRAINED SPOTTER

            PEA SIZED HAIL ACCOMPANIED THE WIND.

1112 PM     HAIL             3 SW BLOOMINGTON        39.14N 86.56W
08/13/2011  M1.00 INCH       MONROE             IN   TRAINED SPOTTER


&&

$$

National Weather Service Weather Forecast Office

August 13, 2011 Central Indiana Severe Weather