PRECEDING FORECAST SOUNDING FOR EVENT:
WHITE-POSEY-GIBSON COUNTY EF3 TORNADO (PEAK WINDS 152 MPH)
The tornado illuminated by lightning north of Poseyville (courtesy of Jason Gerteisen)
44 VIPIR RADAR DATA FROM NWS OWENSVILLE RADAR SITE……….
We had been tracking this supercell for a long time. At 8:50 p.m., it was already producing a damaging tornado, per spotter reports. It was clearly seen on radar 29 miles west-southwest of the Hamilton County line & moving east-northeastward.
A major long-track, cyclical HP supercell, with origins near Joplin, Missouri carved an approximate 514-mile path of destructive, deadly strong, long-track tornadoes, large, damaging hail & severe wind gusts.
There were three round of storms with our severe weather outbreak………round 1 had supercells Wayne to Clay, Richland, Lawrence & Knox counties, round 2 had multiple supercells & a line segment (with the one dominant supercell) & round 3 had the squall line. This all occurred 8 p.m.-8 a.m. February 28-March 1. Out of all of this, the dominant storm was this main, significant supercell, however.
Here it is at 9:15 p.m. after producing the deadly EF4 tornado in a 50.4-mile path from Missouri to southern Illinois & other weaker tornadoes. It was cycling back to a violent supercell again.
At this point, the low-level rotation was tightening south-southwest of McLeansboro.
During this time, this cyclical HP supercell was re-organizing rapidly & a brief tornado was reported by a trained NWS weather spotter at Enfield.
Just prior to this tornado at Enfield, 2.50″ hail broke windows in eastern Hamilton County. Then hail was not reported, until just before the tornado developed near Crossville. 1-2.50″ stones were reported. All along the supercell track, it was noted that large hailstone fall preceded tornado development &/or intensity.
This was the time the tornado was touching down near Crossville, just five minutes following reports of a new round of large hailstones falling.
Immediately, the velocity indicated +122 mph winds at radar beam level & a clear debri ball signature was highly-visible on radar. This was pieces of homes, businesses, farm buildings, grain bins & large trees being hurled & pulled up into the tornado. At 10:03 p.m., this debri ball was just northwest of Phillipstown & likely contained much debri from the south & southeast side of Crossville.
Significant debri ball was seen as the tornado crossed the Wabash River around 10:07 p.m. Here, velocity showed +130 mph winds at the Owensville radar beam level.
Vipir radar clearly showed this was a tornado on the ground as it approached Griffin.
Clearly-defined debri ball was still visible as it just began to cross I-64 in these images. This debri completely closed I-64 in both directions for an extended period of time.
Here is the significant tornado about to cross Route 165 around Wassmer Road & County Road 1000 South just northwest of the 165/I-64 exit at Poseyville. Debri ball signature is still seen in the tornado.
Damaging tornado was on the move northeast in rural Gibson County very close to the Owensville NWS radar site. +115 mph winds were measured very close to the radar site in the tornado.
The tornado continue on a path toward Fort Branch. At 10:29 p.m. tornado was crossing Route 168.
Minutes later, the tornado was south of Francisco. With reports of significant damage, the alarm was up for the Oakland City area.
This a view of the classic tornado signature approaching I-69 northwest of Somerville with pieces of debri being strewn unto the interstate as a nearby grain bin was obliterated.
Tornado lifted quite abruptly southeast of Oakland City. Here, you can see the very distinct tornado signature is diffuse as it is likely just a wall cloud at this point. This was the end of its approximate 45-mile track of destruction. Swaths of large hail fell north of it, varying reportedly in size from 1″ to 2.50″ in diameter.
DUBOIS COUNTY EF2 TORNADO (PEAK WINDS 130 MPH)
The same supercell produced the relatively brief EF2 tornado in western Dubois County. The long-track EF3 was visiblity, being illuminated by lightning, for much of its track. However, the Ireland tornado was likely completely enclosed by rainfall.
DAVIESS COUNTY, INDIANA TORNADOES…..(TWO EF1s, TWO EF2s WITH PEAK WIND 125 MPH)
4:10 a.m. & 4:14 a.m.
The Daviess County (Indiana) tornadoes occurred with Round 3 or the squall line. These were brief tornadoes, but two of the four that touched down southeast of Washington & south of Montgomery were EF2s with peak winds of 113 mph & 125 mph. These tornadoes moved southeastward, not northeastward like the supercell tornadoes of hours earlier in round 2.
4:01 a.m.-4:44 a.m.
Two circulations are visible on the front of the line in two notches. One was nearing tornado production south of Washington. The other circulation was just east of the Daviess County Airport.
Minutes later, circulation was seen along 257 southeast of Washington, while other circulation was at Montgomery.
These two circulations continued to move southeastward.
The one easily-visible at 4:10 a.m. near Corning has just produced the tornadoes near Montgomery with the other southwest of Alfordsville.
The dominant circulation that produced the two EF2s produced the EF2 near Mitchell (as you can see in final image). This tornado continued into Orange County.
It is noteworthy that the bright pink bulge north of this tornado became increasingly downburst-dominated & produced many gusts of 90-100 mph through Washington County, Indiana.
MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE WITH THE OFFICIAL STORM SURVEYS & SUMMARIES (Paducah, Louisville, Indianapolis):