2013-05-31 EVENT: KS, OK, MO, IL

[Bob Schafer]

Yeah, this is probably the biggest laugh I ever got from any weather discussion, anytime, anyplace:

http://www.nhc.noaa.gov/archive/2004/dis/al092004.discus.067.shtml?

 

[Shawn Schuman]

Yeah, this is probably the biggest laugh I ever got from any weather discussion, anytime, anyplace:

http://www.nhc.noaa.gov/archive/2004/dis/al092004.discus.067.shtml?

You may not have seen the saga of Epsilon and Zeta from the 2005 hurricane season then.

Illustrated by xkcd, but of course the actual advisories can be found online as well.

Sorry if I'm getting too off-topic here, but this is one of my favorite weather-related anecdotes.

 

[Jeff Wright]

How does Mulhall compare to El Reno?

Not a lot of great pictures of Mulhall due to the darkness:
http://www.photolib.noaa.gov/htmls/nssl0211.htm
http://www.stormeyes.org/tornado/3may99/vmulhal2.jpg http://www.stormeyes.org/tornado/3may99/vmulhal3.jpg

The Mulhall supercell looks very conventional if large. I wonder if El Reno was in the process of absorbing another broader circulation to its west, to circle around and then drop.

The one tornado I would love to travel back in time to study was Guin 1974.

From the wiki: "The destruction was so complete, that even some of the foundations were dislodged and swept away as well."

That sucker stayed on the ground and its path visible from space--even when not seen up close as on recent storms.

 

[Jeff Wright]

I wonder if the diffuse look might have lulled people into thinking it was less intense.

It is very hard to determine scale at distance. A photographer can make a Delta II rocket look as big as a Saturn V after all-depending on how he frames the shot.

A very very wide tornado plays tricks with your mind unless it has a very sharp funnel. Moore 1999, when if filled one frame nearly side to side looked to have a very clear edge.

I love your film style Skip. The Weather Channel needs to have you and others do a documentary on this--not just the aftermath as is too often done.

 

[Tim Vasquez]

I felt I had to throw this into the thread for a different perspective of this historic storm. It's a garden-variety shot of the anvil cloud of the El Reno storm looking east from my office in rural east Norman. The time was 6:33 pm CDT. Continuous rumbling. The anvil was pretty active with crawlers.

Tim

 

[Jeff Wright]

Something I'd like to see--if I might make a request. Since it is so hard to judge size of funnels, could any of you show two photos of Moore 1999 and Reno 2013 side by side (you may be able to shrink one down) and perhaps do line drawings.

I remember the first wedge I saw growing up (when they were called maxi's) was Wichita Falls.

 

[JamesCaruso]

I have been assuming that the reason Tim Samaras and crew, and other chasers, got in trouble this day was from the combined effect of (a) the tornado's sudden, sharp left turn, and (b) its rapid expansion from one mile wide to 2.5 miles wide in 30 seconds. With regard to the expansion, however, I am wondering how that jives with the track map we have all seen (attached here for ease of reference), which seems to show a much more gradual widening over distance, which in turn would seem to have taken more than 30 seconds even assuming a forward speed of 40 mph at that time. The track map just does not seem consistent with the time/space relationship implied by the stated rate of expansion. What am I missing? Am I just underestimating the expansion represented in this track map?

 

[David Hoadley]

I had the same problem as you but am guessing that the earlier tornado of around a mile wide --west of US81, was rotating about the core of an even larger meso cyclone. Such turning about a core could have covered a wider damage track than the earlier tornado width. When it expanded to 2.6 miles east of US81, it may have stopped that larger rotation track. Since the path east of US81 is a little more than 3 miles wide, possibly, some of the later ground damage was due to strong inflow winds. That is one way of trying to make this damage pattern fit the changing tornado size.

 

[Jeff Snyder]

Who said that the tornado expanded from 1 to 2.5 miles wide in only 30 seconds? I've read that several times and in several locations, but I haven't found the true source. It doesn't really match our radar observations, but we also have a data gap for several minutes as it crosses 81.

 

[Dan Robinson]

Jeff, I seem to remember reading that in the PNS, but now that I search for it on the NWS Norman site, it's not in the original. I only see it on a non-NWS web site I see via a Google search. It may have been an embellished version of the official PNS that went viral.

 

[Dave Chapman]

I've been assuming that "path" is the tornado cyclone rotating around the mesocyclone, both before and after the tornado cyclone reached the ground.

There may have been two jumps in size. After it crossed Reno Road just west of me it was still in multi-vortex mode, but over the next few minutes the circulation engulfed a number of chasers. The jump from a mile to two-and-a-half miles seems to have been equally dangerous especially with the satellite tornadoes. And the fact the entire thing was rain-wrapped much of the time helped disorient chasers as to its direction changes.

 

[Jason Harris]

One source of the 30-second claim:

TwitterReed Timmer @reedtimmerTVN
El Reno tornado on May 31 just upgraded to #EF5. Went from less than a mile to 2.6 miles wide in around 30 sec. Widest #tornado in history

Read more: http://livewire.kmbc.com/Event/Live_updates_as_heavy_rain_moves_through_Kansas_City#ixzz2WIbcYvMA

It seems other people used similar descriptions who were there on the ground:
__
Within a matter of seconds the tornado expanded like nothing I’ve seen before, and became 2.6 miles wide. This is the new record for tornado width in the U.S., and likely makes it the largest tornado in the world. It was rated EF5.

http://stormgasm.com/blog/?p=1595

 

[Jason McKittrick]

Who said that the tornado expanded from 1 to 2.5 miles wide in only 30 seconds? I've read that several times and in several locations, but I haven't found the true source. It doesn't really match our radar observations, but we also have a data gap for several minutes as it crosses 81.

Having been there to see it from 1 mile south of the track the expansion was undeniably obvious and the 30 sec time frame was my estimate as well. However I question the size. I observed the tornado expansion from a large cone with multiple vortices to a wedge. I estimated that it was 1/8 to 1/4 mile wide before and roughly a mile give or take after. Seeing this occur was stunning.

We did observe damage being done by the inflow at our position. We saw a couple of barnes loose the roofs in inflow I would estimate to be 70mph+. I suspect the damage survey included these as part of the circulation. However we were approximately 1 mi south of the condensation funnel.

 

[Bob Schafer]

You've all seen this, right? (VERY large file)

http://wdssii.nssl.noaa.gov/web/wdss2/products/radar/NWRT_20130531_ElReno.gif

The incredible, amazing thing about that loop is the forward-motion acceleration that was captured by that radar.

 

[Dan Robinson]

What confused many of us there at the time was that the entire large rain curtain zone *was* the tornado. That was only evident when that entire zone became the wedge after crossing 81. Everyone was focused on what was condensed, which was a major contributing factor to what happened.

It seems clear to me from the data that most of us who thought we were in inflow were in the tornado itself, if just the outer edge. I'm anxious to see the RaxPol data with timestamps which will prove or disprove this.