Tornados in the Metroplex (Dallas, Denton: tornado, moving to, area)

[GoPadge]

A number of posters have questions about tornadoes in the Dallas area. To try and bring some data and order to ease people's minds I thought I'd offer my analysis of data available at www.tornadoproject.com. The data runs from 1950 to 1995 and I've only looked at data as pulled from http://www.tornadoproject.com/alltorns/txtorn1.htm for the counties in the Metroplex, as listed via Wiki at http://en.wikipedia.org/wiki/Dallas-...orth_Metroplex. (Collin, Dallas, Delta, Denton, Ellis, Hunt, Johnson, Kaufman, Parker, Rockwall, Tarrant and Wise counties.) The DFW Metroplex covers an area of 8,991 sq. miles, which is 262 sq mi bigger than New Jersey.

I pulled the data into Textpad (http://www.textpad.com/) a text editor and used it for sorting and determining counts based on number of lines selected.

County..# of..sqmi..sqmi/Tornado
.....Tornadoes

Sorted by number of Tornados
Johnson....68..734..10.79
Dallas.....66..909..13.77
Tarrant....62..897..14.46
Parker.....49..910..18.57
Hunt.......47..882..18.76
Wise.......35..923..26.37
Ellis......35..952..27.2
Collin.....33..886..26.84
Denton.....27..958..35.48
Kaufman....25..807..32.28
Rockwall...11..149..13.54
Delta.......4..278..69.5

Sorted this way Delta Co. has seen the fewest total number of tornadoes and Johnson Co. has seen the most.

Sorted by sq mi/tornado
Johnson....68..734..10.79
Rockwall...11..149..13.54
Dallas.....66..909..13.77
Tarrant....62..897..14.46
Parker.....49..910..18.57
Hunt.......47..882..18.76
Hood.......18..437..24.27
Wise.......35..923..26.37
Collin.....33..886..26.84
Ellis......35..952..27.2
Kaufman....25..807..32.28
Denton.....27..958..35.48
Delta.......4..278..69.5

Sorted this way, Johnson Co. sees more tornadoes per sq mi and Delta Co. see the fewest. But look at the difference in positions for Rockwall county; while it's seen the second fewest based on total number, but has jumped to second most based of number seen per sq. mi.

Looking at historical time frames, the 1970's were the worst decade for tornadoes with 170 incidents. But the 1990's were already the second worst with 101 incidents through 1995.

1950's 49
1960's 79
1970's 170
1980's 31
1990's 101

Looking at offset quarters, (because the peak period seemed to start around March 16th and run through June 15th) 64.9% of the tornadoes were reported in the March 16th - June 15th time frame.

Dec16-Mar15...4.7%
Mar16-Jun15..64.9%
Jun16-Sep15..12.6%
Sep16-Dec15..17.8%
I hope this offers some facts for discussion. (And stops 16 more, "we're moving to DFW, but are scared of the tornadoes" posts....)

[momof2dfw]

Johnson County........... yes, that is one county that always seems to be on the lists of warnings/watches in bad weather along w/ a few others. What hurts Rockwall County is the size, it is the smallest county in the state so it kind of distorts a bit.

As for other counties that always seem to be on the weather warning/watch list (thunderstorms, tornado, etc) I'd say I see these more than any others:
Johnson
Erath
Parker
Wise
Ellis
Tarrant