A large high-precipitation supercell moved into northwest portions of central Indiana during the afternoon hours of August 18th. This supercell then transitioned to compact bow echo as it moved eastward, impacting the heart of the Indy metro area.
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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.
A large high-precipitation supercell moved into northwest portions of central Indiana during the afternoon hours of August 18th. This supercell then transitioned to compact bow echo as it moved eastward, impacting the heart of the Indy metro area. Multiple reports of trees and power lines downed, heavy rain, few large hail reports.
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 Aug 18, 3:37 PM EST, 1 hour 8 minutes earlier.
Area Forecast Discussion National Weather Service Indianapolis IN 437 PM EDT Sun Aug 18 2019 .UPDATE... The Synopsis, Near Term, and Short Term sections have been updated below. && .SYNOPSIS... Issued at 437 PM EDT Sun Aug 18 2019 A remnant boundary may help to develop thunderstorms this afternoon and evening, some of which could be strong to severe, with damaging winds the primary threat. A largely diurnal threat for storms can be expected the next couple of days, with a more substantial storm threat Wednesday with the passage of a cold front. A few storms on Tuesday however could be severe with damaging winds. Conditions late in the period will be cooler with high pressure in the area, along with a few slight chances for storms along the periphery of the upper ridge to the southwest. && .NEAR TERM /This Afternoon and Tonight/... Issued at 437 PM EDT Sun Aug 18 2019 Thus far, convection across the area has struggled, as a weak cap does remain in place. We've got a little while longer for things to develop and move into the area before we start to lose heat, and plenty of instability is in place along with marginal but increasing deep layer shear as a remnant circulation moves toward the area over the next couple of hours. As is typical for the time of year, hail is somewhat of an afterthought, especially today with midlevel lapse rates marginal and freezing levels high. Marginal severe hail cannot be ruled out though, but damaging winds amid a healthy DCAPE and low level lapse rate environment will be the primary threat. Expect convection to wane steadily after the watch expires and should be dry late tonight. Airmass changes only marginally tonight and thicknesses/dewpoints suggest lows near those of last night...70 plus or minus a couple degrees. && .SHORT TERM /Monday through Wednesday/... Issued at 437 PM EDT Sun Aug 18 2019 Storm threats will continue each day through the short term, but will be largely diurnal, with the highest threats in the afternoons and evenings, and lower threats late nights into the mornings. There will be a bit higher threat for storms Wednesday as the cold front passes. On Tuesday, day 3 outlook slight risk nudges into the area, and SPC suggests a climatologically typical high CAPE low-moderate shear MCS with a damaging wind threat. This looks entirely reasonable given our position on the periphery of the upper ridge to our southwest, and this threat will bear monitoring. Temperatures should remain warm, in the neighborhood of 90 during the day and 70 overnight through the short term, cooling quite a bit as the front passes at the end of the period. && .LONG TERM /Wednesday night through Sun/... Issued at 233 PM EDT Sun Aug 18 2019 Models in general agreement that a cold front will crop southeast across central Indiana Wednesday and Wednesday night. The front will interact with a warm, moist and unstable airmass and result in the threat for thunderstorms Wednesday and Wednesday night. Then, the 12z GFS and ECMWF differ in that the Euro brings more QPF in Thursday and Thursday night whereas the GFS does not. The EURO seems to be keying in on upper waves around a Great Lakes through and the western part of the cold front stalling and lifting northeast as a warm front. The blend incorporates both with small PoPs, mainly south through Thursday night. With confidence low, will leave the blend PoPs. Slightly below normal blend temperatures look reasonable. The rest of the weekend looks mostly dry with below normal temperatures as Canadian high pressure builds in. However, would not completely rule out isolated convection in northwest flow aloft. && .AVIATION /Discussion for the 18/18Z TAF Issuance/... Issued at 1247 PM EDT Sun Aug 18 2019 An upper wave will move across central Indiana this afternoon and early evening. This feature will interact with a very warm, moist and unstable atmosphere and result in scattered to numerous thunderstorms through 02z Monday. So, brought in 2 hour tempo MVFR thunderstorm groups with VCTS and VFR after. Should see mostly VFR conditions after 02z per the SREF. However, would not be shocked to see MVFR for 09z-13z per the GFS LAMP. Winds will be southwest to 15 knots away from storms through 00z and then southwest less than 10 knots after. && .IND WATCHES/WARNINGS/ADVISORIES...NONE. && SYNOPSIS...Nield NEAR TERM...Nield SHORT TERM...Nield LONG TERM...MK AVIATION...MK
Hazardous Weather Outlook National Weather Service Indianapolis IN 424 AM EDT Sun Aug 18 2019 INZ021-028>031-035>049-051>057-060>065-067>072-190830- 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- Including the cities of Delphi, Flora, Williamsport, West Lebanon, Lafayette, West Lafayette, Frankfort, Kokomo, Attica, Covington, Veedersburg, Crawfordsville, Lebanon, Zionsville, Tipton, Fishers, Carmel, Noblesville, Anderson, Muncie, Winchester, Clinton, Newport, Rockville, Greencastle, Plainfield, Brownsburg, Danville, Indianapolis, Greenfield, Cumberland, New Castle, Terre Haute, Brazil, Clay City, Spencer, Martinsville, Mooresville, Greenwood, Franklin, Shelbyville, Rushville, Sullivan, Linton, Bloomfield, Bloomington, Nashville, Columbus, Greensburg, Vincennes, Washington, Loogootee, Shoals, Bedford, Mitchell, Seymour, Brownstown, and North Vernon 424 AM EDT Sun Aug 18 2019 This hazardous weather outlook is for central Indiana. .DAY ONE...Today and Tonight. Outlook: Thunderstorms are possible this afternoon and tonight. An isolated severe storm cannot be ruled out. Timing: Mainly after 2 PM. Hazards: Lightning, Heavy Rain, Gusty Winds. Discussion: A lingering warm frontal boundary combined with upper level support may allow additional showers and thunderstorms to redevelop today and this evening across Central Indiana. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Outlook: There will be periodic chances for thunderstorms through the middle of next week for parts of central Indiana. Hot and humid weather will continue through Wednesday with heat indices peaking in the mid and upper 90s in the afternoons. Discussion: A series of weak upper level weather disturbances will interact with lingering surface boundary to bring some chances for isolated showers and storms to much of central Indiana. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated at this time. && More information, along with other weather, hydrological and climate information can be found at http://weather.gov/ind PUMA
Special Weather Statement
National Weather Service Indianapolis IN
302 PM EDT Sun Aug 18 2019
INZ051-052-060-181945-
Clay IN-Vigo IN-Sullivan IN-
302 PM EDT Sun Aug 18 2019
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN VIGO...NORTHEASTERN
SULLIVAN AND SOUTHWESTERN CLAY COUNTIES UNTIL 345 PM EDT...
At 302 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles north of Sullivan, or 16 miles southeast of Marshall, moving
northeast at 20 mph.
Nickel size hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Shelburn, Farmersburg, Clay City, Fairbanks, Riley, Cory, Saline City
and Pimento.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
southwestern and west central Indiana.
LAT...LON 3932 8748 3948 8720 3939 8712 3930 8705
3926 8706 3916 8747 3922 8757 3923 8757
TIME...MOT...LOC 1902Z 239DEG 19KT 3924 8746
AWThe Indianapolis radar (KIND), 107 km away, was scanning. The volume nearest the first event began at 21:48 UTC.
14 thunderstorm wind, 2 hail. Local standard time, as filed.
Several small to medium size tree limbs were down and power was out in this location due to damaging thunderstorm wind gusts.
Trees were downed, including on to power lines, in this location due to damaging thunderstorm wind gusts.
This was a public report of an estimated 60 mph thunderstorm wind gust in this location.
An estimated 65 mph thunderstorm wind gust was observed in this location.
Several 4-inch tree limbs were snapped due to damaging thunderstorm wind gusts.
An 8-inch tree limb and a 12-inch tree was snapped due to damaging thunderstorm wind gusts.
An estimated 60 mph thunderstorm wind gust was observed in this location.
A tree with an 18-inch base was downed due to damaging thunderstorm wind gusts.
A small tree and multiple large limbs were snapped at the Indianapolis Weather Forecast Office due to damaging thunderstorm wind gusts.
A mesonet station measured a 59 mph thunderstorm wind gust in this location.
A picture of this event looked like multiple smaller hailstones were fused together.
An estimated 60 mph thunderstorm wind gust was observed in this location.
Numerous 4 to 6-inch tree limbs were snapped due to damaging thunderstorm wind gusts.
A measured 65 mph thunderstorm wind gust was observed in this location.
Several large tree limbs and power poles were snapped due to damaging thunderstorm wind gusts.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Indiana in 2019Every state in 2019This day in weather historyWarnings in Indiana, August 2019
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: 837139, 837145, 837170, 837177, 837199, 837207, 837208, 837214, 837224, 837243, 837267, 837271, 837274, 837276, 837279, 837280.