cdcollura
EF5
Some severe weather, including supercells, were observed in Northern Ohio on May 1, 2007.
This chase started by heading north on Interstate 75 out of Dayton, Ohio at about 2:30 PM for the original target area near and southeast of Toledo, OH. Forecasting earlier that day revealed a warm-frontal boundary draped across northern Ohio with a developing surface low near Chicago, IL. Surface winds south of this boundary were WSW with temperatures in the low 80's (with a dewpoint near 60) and easterly winds and temperatures in the 60's north of it.
Upper winds at 500 and 300 MB were WNW at up to 50 and 80 knots, respectively. Lapse rates were also steep (6 - 7 deg C) in this area as well, so the main mode expected would be large hail with any tornado possibilities early during initiation before evolution to multicell severe mode. According to SPC, the outlooks issued were nearly identical on both the 16:30z and 20:00z outlooks, with a 5% tornado, 30% hail, and 30% damaging wind probability. A mesoscale discussion (MCD 0636) went out for the area and a severe thunderstorm watch (205) was issued for northern Ohio valid until 8 PM EDT.
The chase continued north with a data-stop in Lima, OH where an isolated developing supercell storm was noted just south of Toledo, OH. Rushing north and northeastward on Interstate 75, this supercell was noted visually and approached from the southwest. Headed east on Highway 6 into Wood County, the updraft portion of this severe (and radar-indicated tornado) warned storm was noted near Fremont, and a large RFD clear-slot was noted. The storm core was not penetrated and no tornadoes were observed with this storm. It eventually moved north of the boundary, became elevated, and weakened.
More storms began developing to the south, and another severe storm developed in this area by about 6 PM. Heading east and then southeast on Highway 20 through Sandusky County, then south on Highway 250 / State-Road N (detour for 250) out of Norwolk, this severe storm was encountered and large hail covering the ground was observed northeast of North Fairfield and Highway 162. These storms moved east very quickly, and the one near North Fairfield had some interesting features / lowerings on its updraft. Hail up to 1" was observed with this storm before it moved rapidly east and weakened.
Heading east on Highway 162 through northern Ashland County, another small supercell-type storm developed to the northest of Ashland, OH by about 7 PM. The core of this small storm was not penetrated, but its updraft and hail-shafts were noted. This storm became severe-warned, but weakened shortly after. Heading south on 301 near Spencer, then towards Interstate 71, one final severe storm was encoutnered near West Salem, and flash flooding started to occur in the area by about 8 PM. SPC also issued another Mesoscale discussion (MCD 0637) and severe thunderstorm watch 206 valid until 11 PM EST for a bit farther east than expired watch 205.
By this time most storms were line-segments and clusters, so the chase was wrapped up at dark by heading back SW along Interstate 71, then to Interstates 270 and 70 near Columbus, then returning to Dayton off Interstate 75 by about 10 PM. The total mileage for this chase was just under 413 miles.
Much more details can be seen on this chase by clicking the link below...
http://www.sky-chaser.com/mwcl2007.htm#MAY01

This chase started by heading north on Interstate 75 out of Dayton, Ohio at about 2:30 PM for the original target area near and southeast of Toledo, OH. Forecasting earlier that day revealed a warm-frontal boundary draped across northern Ohio with a developing surface low near Chicago, IL. Surface winds south of this boundary were WSW with temperatures in the low 80's (with a dewpoint near 60) and easterly winds and temperatures in the 60's north of it.
Upper winds at 500 and 300 MB were WNW at up to 50 and 80 knots, respectively. Lapse rates were also steep (6 - 7 deg C) in this area as well, so the main mode expected would be large hail with any tornado possibilities early during initiation before evolution to multicell severe mode. According to SPC, the outlooks issued were nearly identical on both the 16:30z and 20:00z outlooks, with a 5% tornado, 30% hail, and 30% damaging wind probability. A mesoscale discussion (MCD 0636) went out for the area and a severe thunderstorm watch (205) was issued for northern Ohio valid until 8 PM EDT.

The chase continued north with a data-stop in Lima, OH where an isolated developing supercell storm was noted just south of Toledo, OH. Rushing north and northeastward on Interstate 75, this supercell was noted visually and approached from the southwest. Headed east on Highway 6 into Wood County, the updraft portion of this severe (and radar-indicated tornado) warned storm was noted near Fremont, and a large RFD clear-slot was noted. The storm core was not penetrated and no tornadoes were observed with this storm. It eventually moved north of the boundary, became elevated, and weakened.

More storms began developing to the south, and another severe storm developed in this area by about 6 PM. Heading east and then southeast on Highway 20 through Sandusky County, then south on Highway 250 / State-Road N (detour for 250) out of Norwolk, this severe storm was encountered and large hail covering the ground was observed northeast of North Fairfield and Highway 162. These storms moved east very quickly, and the one near North Fairfield had some interesting features / lowerings on its updraft. Hail up to 1" was observed with this storm before it moved rapidly east and weakened.

Heading east on Highway 162 through northern Ashland County, another small supercell-type storm developed to the northest of Ashland, OH by about 7 PM. The core of this small storm was not penetrated, but its updraft and hail-shafts were noted. This storm became severe-warned, but weakened shortly after. Heading south on 301 near Spencer, then towards Interstate 71, one final severe storm was encoutnered near West Salem, and flash flooding started to occur in the area by about 8 PM. SPC also issued another Mesoscale discussion (MCD 0637) and severe thunderstorm watch 206 valid until 11 PM EST for a bit farther east than expired watch 205.

By this time most storms were line-segments and clusters, so the chase was wrapped up at dark by heading back SW along Interstate 71, then to Interstates 270 and 70 near Columbus, then returning to Dayton off Interstate 75 by about 10 PM. The total mileage for this chase was just under 413 miles.
Much more details can be seen on this chase by clicking the link below...
http://www.sky-chaser.com/mwcl2007.htm#MAY01