Some tornadic Wind Damage Friday night

Most of the damage on Friday night looks like microburst or straight line wind damage. There are a couple of terms and conclusions I want to post about as well. For right now read the report and I'll give you my assessment in my next post:

Swath of Wind Damage and Tornadoes across portions of Northern Indiana and northwestern Ohio June 6th, 2008

Synopsis

A line of thunderstorms moved across central Indiana and expanded northeastward into northeastern Indiana and northwestern Ohio. The greatest concentration of storms was from southern Miami county to Allen county Indiana and then northeast to Fulton County Ohio. The line of storms rapidly began bowing out with velocity data signatures of winds in the 70 to 80 mph range. Severe Thunderstorm and Tornado Warnings were issued along the line during the evening hours of the 6th.

Preliminary Damage Survey Summaries

**Review of Survey Information and data continues with revisions to the summaries below possible***
NWS personnel, in cooperation with county Emergency Management officials, conducted surveys of the wind damage to determine if distinct damage could be found which would be associated with tornadic development. Numerous eye witness reports came in of funnel clouds and possible tornado touchdowns from Grant county, into Wells and Adams counties in Indiana and Van Wert county in Ohio. Many of these were gustnadoes, or gust front tornadoes, which rapidly develop on the leading edge of a fast moving lines of storms. According to current classification standards, gustnadoes are classified as thunderstorm winds and not tornadic winds. That does not diminsh the threat that they can pose or the fact that they look and act just like tornadoes. The vast majority of the damage in this swath was the result of damaging straight line winds on the order of 60 to 80 mph. Damage indications in a few areas leaned toward peak wind speeds around 90 mph as well.

Grant County
Damage patterns indicate that at least one brief tornado did occur just to the northwest of Marion, Indiana in Grant county. A EF1 tornado touched down around 733 pm EDT in a heavily forested area just south of the 4 Mile Bridge, west of State Route 15 and lifted immediately just across the road at 735 pm EDT. Damage was confined to mature trees and roof damage with a peak width of 50 yards and a path length just shy of two tenths of a mile. Extensive tree damage and terrain prevented a more accurate assessment of the path length. Winds were estimated between 90 and 100 mph. Wind speeds of a EF1 range from 86 to 109 mph on the Enhanced Fujita Scale (EF Scale).

The tornado mentioned above appeared to have occurred coincident with a microburt wind event which originated to the southwest in a subdivision north of West Harreld Road and west of Frances Slocum Trail. This wind swath widened out to three quarters of a mile after it crossed State Route 15 and impacted another subdivision with substantial tree damage. Winds were estimated at between 65 and 85 mph. Additional sporadic wind damage was noted through the remainder of the county, with one more extensive area of straight line wind damage found near the town of Fowlerton. Winds were estimated at up to 75 mph.

Wells and Adams Counties
Several areas of concentrated damage were seen across Wells and Adams county during a seperate survey. The majority of the damage was consistent with straight line winds. The wind speeds that were esimated, which were in the 80 to 90 mph range, would have overshadowed any small damage patterns which may have been created by what was likely several brief gustnadoes. Much of the wind damage was found along and north of US 224 across these two counties.

Scattered tree damage was found across Wells county with highlights including a rolled semi-trailer near Rockford and a 10,000 pound RV rolled into a barn 3.5 miles northwest of Bluffton.

Significant tree damage was found scattered across Adams county as well, espeically near and around Decatur. Large signs and rooftops of businesses were damaged with many houses suffering minor roof damage.

Van Wert County
Just as was observed in adjacent Adams county Indiana, widespread reports of wind damage, with speeds estimated as high as 90 mph across Van Wert county. Early indications of a possible tornado in the county were reconsidered after examination of damage, radar data and intense discussion with other NWS staff members. Due to the strength of the winds, specific tornado tracks were difficult at best to be ascertained in the county. Several eye witness reports in the county stated observing a wall or blast of high winds and dust which was then proceeded several minutes later by heavy rain and small hail.