A stalled frontal boundary, combined with some tropical moisture from the remnants of Hurricane Lori to produce a broken line of pulse thunderstorms. A few reports of damaging wind occurred.
Every event with a place to put it. 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 IWX wrote it up.
A stalled frontal boundary, combined with some tropical moisture from the remnants of Hurricane Lori to produce a broken line of pulse thunderstorms. A few reports of damaging wind occurred.
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 Northern Indiana wrote its last area forecast discussion before the first event at Aug 27, 2:29 PM EST, 26 minutes earlier.
Area Forecast Discussion National Weather Service Northern Indiana 329 PM EDT Thu Aug 27 2020 .SYNOPSIS... Issued at 239 PM EDT Thu Aug 27 2020 Hot and humid this afternoon and evening with isolated to scattered showers and thunderstorms. There are even better chances for showers and thunderstorms Friday afternoon and evening. Cooler weather will return this weekend. Breezy northwest winds will create dangerous swim conditions on Lake Michigan Saturday. && .SHORT TERM...(This Evening through Friday night) Issued at 239 PM EDT Thu Aug 27 2020 High pressure nosing into the area from the southeast will allow the hot weather to continue through Friday. There is a frontal boundary to the north across central Michigan, while Hurricane Laura continues to make its way northward through the lower Mississippi Valley. Southwesterly low-level flow into the local area has brought increasing moisture, and PWs will increase to almost 2 inches this evening. This moist unstable airmass has resulted in the development of isolated to scattered showers and thunderstorms. There is still a lot of dry air aloft, so while the threat of severe storms is low since we are lacking a good upper level trigger and shear is only marginal, some storms may become large enough to produce gusty outflow winds or hail. Heavy rain is also possible with these storms as they are somewhat slow moving and are training linearly across northern Indiana. Some activity could persist through the night, although the loss of daytime heating should help limit coverage. There is a better chance of convection on Friday as the environment continues to moisten ahead of an approaching shortwave. Scattered storms can be expected through much of the day, with the best chance for severe weather late afternoon through evening as the shortwave moves in ahead of a cold front. The biggest threat is wind, as is usual, but cannot rule out the possibility of hail or even a brief tornado, especially near the warm front over lower Michigan where shear will be better. The cold front is not expected to come through until after sunset, so instability will be on the decrease, but models are in pretty good agreement that a line of storms with gusty winds will come through after 9 PM EDT. This line should weaken and break up before reaching Ohio as the surface low lifts into New England. && .LONG TERM...(Saturday through Thursday) Issued at 239 PM EDT Thu Aug 27 2020 It will be cooler and drier behind the cold front for Saturday and Sunday. Breezy northwest winds will also follow the front. With gusts around 25 mph over Lake Michigan on Saturday, there is a high risk of rip currents and large waves, causing very dangerous swim conditions. Winds will shift to the northeast and subside on Sunday, but there will still be a moderate risk for dangerous currents. Another quick moving cold will swing through Monday night, but the upper level flow will split as it does with better rain chances to the north and south, so the local area may remain dry. From Tuesday onward, the forecast becomes even more uncertain with model disagreement over the location and timing of shortwaves moving through broad synoptic troughing over the Great Lakes. Therefore kept the slight chance to chance pops provided by the NBM during this period. && .AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon) Issued at 132 PM EDT Thu Aug 27 2020 Isolated convection expected this afternoon given moderate instability/moisture but limited forcing. Hi-res CAM's and surface/satellite obs indicate potential for a gap around the terminals with weak convergence boundary focused east of KSBN and north of KFWA while southern wave remains focused south of KFWA. Have therefore held off on thunder mention for now. Certainly wouldn't rule out a stray storm at either site but confidence in coverage and timing is just too low to mention. Very similar story for later tonight/early Friday as cold front across central Michigan slowly inches south. Better coverage expected but thunder will still be hit and miss with high uncertainty on timing. Also some potential for another round of early morning stratus but signal in forecast soundings is weaker than this morning's event and will hold off mentioning. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...NONE. MI...NONE. OH...NONE. LM...NONE. && SYNOPSIS...Cobb SHORT TERM...Cobb LONG TERM...Cobb AVIATION...AGD Visit us at www.weather.gov/iwx Follow us on Facebook...Twitter...and YouTube at: www.facebook.com/NWSNorthernIndiana www.twitter.com/nwsiwx www.youtube.com/NWSNorthernIndiana
Hazardous Weather Outlook National Weather Service Northern Indiana 337 PM EDT Thu Aug 27 2020 INZ004>009-012>018-020-022>027-032>034-MIZ078>081-OHZ001-002-004-005- 015-016-024-025-281945- St. Joseph IN-Elkhart-Lagrange-Steuben-Noble-De Kalb-Starke-Pulaski- Marshall-Fulton IN-Kosciusko-Whitley-Allen IN-White-Cass IN-Miami- Wabash-Huntington-Wells-Adams-Grant-Blackford-Jay-Cass MI- St. Joseph MI-Branch-Hillsdale-Williams-Fulton OH-Defiance-Henry- Paulding-Putnam-Van Wert-Allen OH- 337 PM EDT Thu Aug 27 2020 /237 PM CDT Thu Aug 27 2020/ This Hazardous Weather Outlook is for northern Indiana, southwest Michigan and northwest Ohio. .DAY ONE...This afternoon and tonight. Heat indices will be in the low to mid 90s this afternoon. Isolated to scattered showers and thunderstorms this afternoon, with a low chance that some activity could last through the night. Isolated strong to severe storms are possible with wind or hail, but chances are low. Localized heavy rain is also possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are possible Friday afternoon and Friday night. A few storms may be strong to severe late Friday afternoon and evening with hail and wind the biggest threats. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. INZ003-MIZ077-281945- La Porte-Berrien- 337 PM EDT Thu Aug 27 2020 /237 PM CDT Thu Aug 27 2020/ This Hazardous Weather Outlook is for northern Indiana and southwest Michigan. .DAY ONE...This afternoon and tonight. Heat indices will be in the low to mid 90s this afternoon. Isolated to scattered showers and thunderstorms this afternoon, with a low chance that some activity could last through the night. Isolated strong to severe storms are possible with wind or hail, but chances are low. Localized heavy rain is also possible. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are possible Friday afternoon and Friday night. A few storms may be strong to severe late Friday afternoon and evening with hail and wind the biggest threats. Hazardous swimming conditions are expected at Lake Michigan beaches Saturday. .SPOTTER INFORMATION STATEMENT... Spotter activation may be needed. LMZ043-046-281945- New Buffalo MI to St Joseph MI-Michigan City IN to New Buffalo MI- 337 PM EDT Thu Aug 27 2020 This Hazardous Weather Outlook is for the nearshore waters of southeastern Lake Michigan. .DAY ONE...This afternoon and tonight. An isolated thunderstorm is possible this afternoon. Severe weather is unlikely. .DAYS TWO THROUGH SEVEN...Friday through Wednesday. Thunderstorms are possible Friday afternoon and Friday night. A few storms may be strong to severe late Friday afternoon and evening with hail and wind the biggest threats. Hazardous conditions likely for small craft Saturday. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time.
Special Weather Statement
National Weather Service Northern Indiana
239 PM EDT Thu Aug 27 2020
INZ004-271915-
St. Joseph-
239 PM EDT Thu Aug 27 2020
...A STRONG THUNDERSTORM WILL AFFECT ST. JOSEPH COUNTY...
At 238 PM EDT, a strong thunderstorm was located near Crumstown,
moving east at 25 mph.
Wind gusts up to 50 mph and pea size hail are possible with this
storm.
Locations impacted include...
South Bend, Mishawaka, Gulivoire Park, Osceola, North Liberty, New
Carlisle, Lakeville, Lydick, Crumstown, Wyatt and Woodland.
&&
LAT...LON 4156 8650 4157 8649 4160 8649 4170 8646
4168 8606 4148 8606 4148 8615 4155 8650
TIME...MOT...LOC 1838Z 282DEG 23KT 4162 8637
HAIL...0.25IN
WIND...50MPH
NWSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTHERN INDIANA
329 PM EDT THU AUG 27 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0326 PM HEAVY RAIN 4 E CRUMSTOWN 41.63N 86.33W
08/27/2020 M1.31 INCH ST. JOSEPH IN MESONET
40 MINUTE RAINFALL AMOUNT.
&&
SKIPPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORTHERN INDIANA
340 PM EDT THU AUG 27 2020
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0335 PM HEAVY RAIN 2 S MONOQUET 41.26N 85.86W
08/27/2020 M1.31 INCH KOSCIUSKO IN MESONET
50 MINUTE RAINFALL AMOUNT.
&&
SKIPSpecial Weather Statement National Weather Service Northern Indiana 351 PM EDT Thu Aug 27 2020 INZ004-272015- St. Joseph- 351 PM EDT Thu Aug 27 2020 ...A STRONG THUNDERSTORM WILL AFFECT CENTRAL ST. JOSEPH COUNTY... At 349 PM EDT, a strong thunderstorm was located near Lakeville, or near Gulivoire Park, moving east at 25 mph. Winds in excess of 40 mph and pea size hail are possible with this storm. Locations impacted include... South Bend, Mishawaka, Gulivoire Park, North Liberty, Lakeville, Crumstown, Wyatt and Woodland. && LAT...LON 4163 8641 4165 8606 4148 8606 4151 8645 TIME...MOT...LOC 1949Z 276DEG 24KT 4157 8629 HAIL...0.25IN WIND...40MPH NWS
The Northern Indiana radar (KIWX), 56 km away, was scanning. The volume nearest the first event began at 19:56 UTC.
4 thunderstorm wind. Local standard time, as filed.
The public reported a large tree was blown down across the road near the intersection of Mulberry and Madison Road.
Emergency management officials reported several trees and large tree limbs down in the city of Springville.
County dispatch reported a tree was blown down onto a power line near the intersection of Roosevelt and Miami Roads.
Local media relayed reports of trees and tree limbs blown down, including onto one home, on the south side of South Bend.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Indiana in 2020Every state in 2020This day in weather historyWarnings in Indiana, August 2020
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: 919634, 919635, 919636, 919637.