1970-10-05: Pottawatomie/Lincoln/Okfuskee Tornado

Jul 17, 2004
379
14
11
61
Piedmont, OK
I was looking up some of the more notable fall severe weather outbreaks here in Oklahoma and noticed this event that was rated F4. As far as I know, this was the strongest tornado recorded outside of the traditional season.

Can anyone give some additional input on how this event unfolded? What was the synoptic set up on this day? Anyone on here remember this day specifically? Below is a link I found about this day where Shawnee and Prague were affected especially by this tornado.


http://www3.gendisasters.com/oklahoma/13260/shawnee-ok-tornado-oct-1970
 
Nov 23, 2005
295
76
11
San Antonio, TX
chaseday.com
Hi Rocky,

This event was my second tornado, the first was in the spring of 1970. This was the beginning year of my first real chases, that is, leaving Tulsa county. Sharon, my wife was in the tornado across the street from the car dealership where the wall fell and killed the two people. She was 13 years old at the time and I didn't know her; we would meet seven years later in an engineering class at OU. She took shelter under a marble table in the Post Office. She tells quite a story, it appears they drove in town under the wall cloud and it pretty much dropped on top of them. Not sure exactly where the track started, but her mother said there was no tornado as they drove in town, just the big low hanging cloud.

Meanwhile, I was driving south on I-44 and caught an exit south. I was in a little sports car (Triumph Spitfire) with my girlfriend. The storm I picked had a long anvil and great convection, but there was no precip under it, just a flat rain free base with a big block of cloud toward the back of it. At the time I had no idea about LP supercells or structure, we were out of radio range, too much static to hear AM 740 out of Tulsa. So it was all visual, no idea Shawnee and Prague had been hit and we were trying to be this days next victims. The cloud on the ground was somewhat boiling, as opposed to rotating and there was a light mist around it. The whole structure was very wide, about 1/2 mile. It filled the wheat field to our west before I realized what we were dealing with so I drove into a deep bar ditch as the north side of the condensation funnel passed over. There were extended periods of green glowing flashes that lit the inside of the vehicle, at the time I thought had something to do with the storm. Of course now I know it was that green glowing flash when high lines and transformers go out, it just lasted a long time in this case. Years later I looked up the day and tried to reconstruct the event, but there was little data available short of buying it from Ashville. I'm pretty sure there was a warm front south of Tulsa in the morning and early afternoon. It appears it gave way to a late season dryline and strong wave. I remember seeing long anvils to my south, so there were other cells, but I think this was the northern extent of the supercells/tornadoes. So, maybe that was the triple point storm, no science here, just speculating. As for photos, I didn't have a camera at the time, at least one capable of capturing this event.

gm
 

Bobby Prentice

Here is some information I compiled about this event. This was the only significant (F2-F5) tornado listed for this day. From the limited weather maps I could compile, this storm must have formed on the dryline. I'm sure someone could use Digital Atmosphere to post a few surface charts for the period 15-21Z.

Significant Tornadoes 1680-1991 by Thomas P. Grazulis said:
OK OCT 5, 1970 1542 CST (2142 Zulu) 4 killed 84 injured 200 yard wide 25 mile path length F4
POTTAWATOMIE/LINCOLN/OKFUSKEE--Moved NE from Shawnee, to Prague, to 2mi N of Paden. At Shawnee, 157 bussinesses, 564 homes, 12 public buildings, five schools, and 10 churches were damage or destroyed. All the deaths and 80 injuries were at Prague. The tornado dipped right in the middle of town, and there was no time to sound the alarm. In Prague, one business and 14 homes were damaged, with four injuries.


 

Bobby Prentice

Jon Finch's web page had a surface chart which suggests the storm might have interacted with an outflow boundary.



 
Nov 23, 2005
295
76
11
San Antonio, TX
chaseday.com
Great information everyone, thanks. The OFB explains everything, the stratus and drizzle boundary in Tulsa during the early part of the day. Also, it looks like a southerly branch shortwave. The Paden tornado had a longer path than indicated in the map. It went to the next county north, Creek, and crossed state highway 48. Either that or there was a second large tornado. I think they lost the damage path in the open fields NE of Paden. Regardless, nice information after all these years.