Multi-day outbreak of May 25-31

[CrazyC83]

Numerous media outlets are reporting it was upgraded to EF-5 with a 2.6 mile width (world record) based on radar observations. Sounds REALLY suspicious to me...I almost think there were two separate tornadoes (which had an overlap on the ground at the same time).

[Dave]

UPDATE: El Reno, Union City tornado widest tornado on record

The National Weather Service has just upgraded the May 31 El Reno, Union City tornado to an EF-5 with a width of 2.6 miles wide, making it the widest tornado ever documented.

EF-5 is the highest possible rating for tornadoes on the Enhanced Fujita scale.

The upgrade was based on information from a Dopler On Wheels (DOW) that measured low level winds of 296 miles per hour.

This tornado is double the width of the May 20 tornado in Moore, Oklahoma.

The F-4 Wilber-Hallam, Nebraska, tornado May 22, 2004 was the previous record holder for the widest tornado on record at 2.5 miles wide.

http://kfor.com/2013/06/04/update-el-reno-union-city-tornado-widest-tornado-on-record/

[EF-5bigj]

Holy crap...

[CrazyC83]

My opinion:

Tornado 1 - touched down south of Calumet based on storm videos. Probably was a single tornado that was up to about 1 mile wide. Roughly followed 15th Street on the southern edge of the enormous mesocyclone. Videos seem to show a new tornado to the north, and probably lifted about 1 minute after that touched down, near Banner Road. Recommended rating: EF-3. No indications of more intense damage along the track.

Tornado 2 - videos seemed to show a multiple vortex tornado with separate circulations near US-81. Hence I believe a second tornado touched down just southeast of El Reno - very close to the chasers - while Tornado 1 was already on the ground, separated by about a mile. This tornado was likely about 3/4 mile wide. It probably tracked eastward to the end of the track as mentioned while narrowing. Recommended rating: a highly uncertain EF-4. That is based on a combination of damage reports and a compromise of radar readings, using high-end numbers for damage due to the incredible vehicle damage.

Additional tornadoes - I also believe some satellite tornadoes may have touched down. Need to look at videos. Most would be rated EF-0 or EF-1.

[EF-5bigj]

Well I guess I can't be shocked its a EF-5. Given the wind velocity's that where recorded and people here saw on radar.

[brunota2003]

296 mph at roughly 500 ft (150m) would translate to what? 250 mph at the surface?

[CrazyC83]

296 mph at roughly 500 ft (150m) would translate to what? 250 mph at the surface?

Not sure how it is over land, but over water, that would be about 250-265 mph using the approximate 85-90% rule from tropical systems.

[Kalrany]

Does anyone know where the report is listed? I am not sure where to look (for example, I didn't see it at the NWS news page). I would like to read a primary source before believing that it is a record-breaker. I am cynical like that...

[Ntxw]

While in my mind I have no doubt this was an EF5 with tremendous winds, I do have a problem with using wind measurements for the sake of continuity. Lets remember the EF system is a damage scale, not a wind scale. If they upgraded this tornado based on those kind of measurements then it opens up a whole new can of worms. I would understand if they created a wind based system of some sort but don't agree on using the EF scale. What about the other big ones that only got recorded as EF0s in the middle of nowhere but looked amazing on radar? Is it fair to pick and choose?

[brunota2003]

While in my mind I have no doubt this was an EF5 with tremendous winds, I do have a problem with using wind measurements for the sake of continuity. Lets remember the EF system is a damage scale, not a wind scale. If they upgraded this tornado based on those kind of measurements then it opens up a whole new can of worms. I would understand if they created a wind based system of some sort but don't agree on using the EF scale. What about the other big ones that only got recorded as EF0s in the middle of nowhere but looked amazing on radar? Is it fair to pick and choose?

They use what is available to them. Other tornadoes have been upgraded due to DOW data. If the data is there, along with the damage supporting it, why wouldn't you rate it what it is?

[Ntxw]

While in my mind I have no doubt this was an EF5 with tremendous winds, I do have a problem with using wind measurements for the sake of continuity. Lets remember the EF system is a damage scale, not a wind scale. If they upgraded this tornado based on those kind of measurements then it opens up a whole new can of worms. I would understand if they created a wind based system of some sort but don't agree on using the EF scale. What about the other big ones that only got recorded as EF0s in the middle of nowhere but looked amazing on radar? Is it fair to pick and choose?

They use what is available to them. Other tornadoes have been upgraded due to DOW data. If the data is there, along with the damage supporting it, why wouldn't you rate it what it is?

EF scale is a damage scale. I did not see a report stating EF5 damage, given I have not seen the damage but nothing from the NWS stating it found such damage. I am not doubting the data, I fully support it but what I am coming from is continuity.

[EF-5bigj]

Has the full survey been released?

[thetruesms]

Numerous media outlets are reporting it was upgraded to EF-5 with a 2.6 mile width (world record) based on radar observations. Sounds REALLY suspicious to me...I almost think there were two separate tornadoes (which had an overlap on the ground at the same time).

Seemed mind blowing to me too, but radar data shows one large tornadic circulation with strong subvortices within the parent circulation.


From one of OU's mobile radars. Man, when I was in the radar group in grad school, I worked with using dual pol radar to infer microphysics of winter precip, not peer into the mysteries of tornadoes with a mobile radar. I really can't help but feel like I missed out

[thetruesms]

EF scale is a damage scale. I did not see a report stating EF5 damage, given I have not seen the damage but nothing from the NWS stating it found such damage. I am not doubting the data, I fully support it but what I am coming from is continuity.

Every tornado from 1950-1972 was retroactively rated using newspaper articles. I'm pretty sure the tornado database has much, much bigger problems than using radar data.

I understand and appreciate your concern for database integrity, but if we ever want to actually get a reliable climatological dataset about tornado intensity (which is what the F/EF scale is already used for, whether that's really valid or not), we need to start using the observations that are available to us. Hopefully, we'll eventually look back at the 1950-20xx tornado dataset the same way we look at pre-satellite hurricane records.

[brunota2003]

http://www.srh.noaa.gov/graphicast.php?site=oun&gc=1

Not the full survey, but there is official confirmation.

The El Reno tornado of May 31, 2013 has been upgraded to an EF-5 with maximum wind speeds of 295 mph. The tornado was 2.6 miles wide at its widest, making it the widest tornado in U.S. history. This is still preliminary and stats may be tweaked as more information becomes available.

[brunota2003]

http://www.srh.noaa.gov/oun/?n=events-20130531

PNS:
http://www.srh.noaa.gov/oun/?n=events-20130531-pns

Code: Select all

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE NORMAN OK
1206 PM CDT TUE JUN 4 2013

...UPDATE ON MAY 31 EL RENO TORNADO...

METEOROLOGISTS WITH THE NATIONAL WEATHER SERVICE AND RESEARCHERS FROM
THE UNIVERSITY OF OKLAHOMA CONTINUE TO INVESTIGATE INFORMATION
RELATED TO THE MAY 31 EL RENO TORNADO.

WITH THIS INVESTIGATION... THE TORNADO HAS BEEN UPGRADED TO AN EF5
TORNADO BASED ON VELOCITY DATA FROM THE RESEARCH MOBILE RADAR DATA
FROM THE UNIVERSITY OF OKLAHOMA RAXPOL RADAR. IN ADDITION... THE
WIDTH OF TORNADO WAS MEASURED BY THE MOBILE RADAR DATA TO BE 2.6
MILES AFTER THE TORNADO PASSED EAST OF US HIGHWAY 81 SOUTH OF EL
RENO. THIS WIDTH IS THE WIDTH OF THE TORNADO ITSELF AND DOES NOT
INCLUDE THE DAMAGING STRAIGHT-LINE WINDS NEAR THE TORNADO AS
DETERMINED BY THE HIGH-RESOLUTION MOBILE RADAR DATA. THE 2.6 MILE
TORNADO PATH WIDTH IS BELIEVED TO BE THE WIDEST TORNADO ON RECORD
IN THE UNITED STATES.

.EL RENO TORNADO 
 
RATING:                  EF5
PATH LENGTH /STATUTE/:   16.2 MILES
PATH WIDTH /MAXIMUM/:    2.6 MILES
FATALITIES:              N/A
INJURIES:                N/A

START DATE:              MAY 31 2013
START TIME:              6:03 PM CDT
START LOCATION:          8.3 WSW OF EL RENO /CANADIAN COUNTY /OK
                           NEAR COURTNEY ROAD ABOUT 1 MILE NORTH
                           OF REUTER ROAD
START LAT/LON:           35.495 / -98.095

END DATE:                MAY 31 2013
END TIME:                6:43 PM CDT
END LOCATION:            6.2 ESE OF EL RENO /CANADIAN COUNTY /OK
                           NEAR INTERSTATE 40 AND BANNER ROAD
END LAT/LON:             35.502 / -97.848

$$

SMITH/GARFIELD/SPEHEGER/AUSTIN


[EF-5bigj]

Well I imagine it scoured the ground so that maybe a reason for the EF-5 rating.

[Kalrany]

Please correct my thinking, but isn't damage and indirect way to measure wind speed anyway? It's that ultimatly what they are trying to achieve? Conversely, isn't wind speed an indirect way to measure damage potential? Or do I missunderstand both? Thanks.

[EF-5bigj]

So the investigation is still on going then. I think the 2011 El Reno was upgraded to EF-5 due to wind measurements as well but that one had EF-5 damage as well.

[CrazyC83]

Numerous media outlets are reporting it was upgraded to EF-5 with a 2.6 mile width (world record) based on radar observations. Sounds REALLY suspicious to me...I almost think there were two separate tornadoes (which had an overlap on the ground at the same time).

Seemed mind blowing to me too, but radar data shows one large tornadic circulation with strong subvortices within the parent circulation.


From one of OU's mobile radars. Man, when I was in the radar group in grad school, I worked with using dual pol radar to infer microphysics of winter precip, not peer into the mysteries of tornadoes with a mobile radar. I really can't help but feel like I missed out

The lower-left picture seems to suggest two tornadoes though (both intense).

The May 24, 2011 tornado had radar complete the upgrade, but it was already high-end EF-4 on initial surveys so there had to be some suspicion of a 5 right away.