13 Years Ago, Significant Fall Severe Weather Outbreak OccurredSeptember 29th, 2012 at 1:19 am by Chad Evans under Chad's WLFI Weather Blog
September 28, 1999 – The Autumn HP Supercells
Three high-precipitation supercell t’storms popped on the outflow boundary from morning/afternoon rain/storms to the north & west amidst a hot, humid airmass on September 28, 1999. Ahead of a strong fall cold front that was to usher in the first light frost of the season & under strong jet stream winds amidst substantial wind shear, the cells very rapidly pulsed up & became severe. The first report of severe weather was a 58 mph wind gust at Pine Village. This was the beginning of a long track of destruction across the heart of the WLFI viewing area as the three supercells evolved into a cluster, then bowing line segment. Flash flooding was an issue with these high-precipitation supercells & 3 corridors of substantial flash flooding developed as extreme rainfall rates occurred. However, the viewing area was in an Extreme Drought, so the rains, albeit very intense & torrential, they did east the drought.
You can certainly understand why this event is one of the top autumn severe events. Imagine +100 mph downbursts, 2-3″ per-hour rainfall rates & golfball sized hail.
Supercell #1: Pine Village to South of Yeoman
Reports of extremely high winds began in northeastern Warren County, then continued east-northeastward, blasting Montmorenci, West Lafayette & Klondyke. One of the highest measured non-tornadic wind gust on record in our viewing area occurred from this storm with a 103 mph gust near Montmorenci. Hundreds of acres of corn & soybeans that were about to be harvested were totally flattened by the apparent macroburst (damage diameter greater than 2.5 miles). A 5th-wheel camper was overturned, injuring the occupant & 2 dozen homes received damage.
The storm continued east-northeastward & dropped an F1, 105 mph tornado on the southwest corner of the supercell, which tracked 4 miles to east-southeast to near Buck Creek. Up to a half-mile wide, it produced over $300,000 in damage. 3 farm tool sheds were totally destroyed with the structural debri found in the tops of trees as far as 1-2 miles away. With the tornado touchdown, golfball-sized hail began to fall from the storm. A second downburst (in this case a microburst) belched from the storm with a measured wind gust of 64 mph at Buck Creek. There is evidence of wind gusts to 80 mph east of Buck Creek. This combined with golfball hail caused siding & roof damage to several homes & destroyed fields of unharvested crops all the way to western Carroll County. Gaping holes were ripped in roofs by the wind-driven large hail. Route 225 was impassable due to fallen trees.
Supercell #2: South of Attica to Flora
Golfball-sized hail began to fall with this supercell southwest of Lafayette. In Lafayette proper, $100,000 in damage was done (largely to cars). Large hail continued with the storm with northeastward progression. Golfball hail was reported at Radnor & Flora. The first downburst (microburst) with this storm occurred near Radnor with a 64 mph wind gust measured & an 80 mph gust causing substantial tree damage. A barn was destroyed by this microburst.
In White County, southwest of Brookston, the large hail core accumulated a snow-like covering several inches deep. Radnor, in Carroll County also reported golfball-sized hail with substantial hail accumulation with a wind gust to 64 mph, as a third microburst was belched from the storm. A barn was destroyed east of Radnor with estimated microburst gusts around 80 mph. Golfball-sized hail was reported at Flora.
Supercell #3: South of Otterbein to Brookston to Fulton (Storm Continued Northeastward with Sporadic, But Impressive Damage to Near Fort Wayne)
The third severe supercell popped just south of Otterbein, tracked into White County & began to produce a prolific golfball hailstorm. Hail accumulated several inches near Brookston. Entire fields of crops were destroyed & trees were totally stripped of leaves. The storm continued northeastward with several inches of golfball hail in northwest Carroll County. The first downburst (in this case microburst) was belched out northwest of Logansport with a 75 mph wind gust that caused tree & power line damage with crops fields damaged. The storm then belched out the second extreme macroburst of the evening with 100 mph wind gust doing heavy damage southwest of Fulton to Nyond Lake & South Mud Lake. This macroburst alone produced over $125,000 in structural damage. This storms second gust, a microburst, produced tens of thousands of dollars in structural damage north of Macy in Miami County. This same storm produced winds up to 80 mph in Whitley, DeKalby & Allen counties. Significant damage to trees & powerlines occurred in Columbia City with many homes receiving minor structural damage. Much of the city had no power for at least 24 hours.
The damage costs to these supercells were phenomenal. In Tippecanoe County alone, just the hail caused over $100,000 in damage to structures. Damage to automobiles was upwards of an additional $100,000 (Tippecanoe County, alone). +$100,000 was done to structures via damaging winds. $300,000 in damage was incurred by the tornado. Crop damage in Warren, Tippecanoe, White, Carroll, Cass, Fulton & Miami counties mounted into the tens of millions of dollars as thousands of acres of crops were flattened or completely destroyed.