Ethel '60: nothing to cat 5<24 hrs;back to TS in 12 hrs!!

[LarryWx]

Wow, what a bizarre storm, Ethel of 1960! It went from less than a TD to a cat. 5 in less than 24 hours and then back to a TS within another 12 hours!! See the following links to the track (I just found about this):

http://weather.unisys.com/hurricane/atl ... /track.dat

http://weather.unisys.com/hurricane/atl ... /track.gif

Anyone else know about this one?

[Derek Ortt]

isn't that the bizzare cat 5 with a 981mb pressure? I cannot see a scenario that would support more than 100KT winds (unless the RMW was about 2NM)

[LarryWx]

isn't that the bizzare cat 5 with a 981mb pressure? I cannot see a scenario that would support more than 100KT winds (unless the RMW was about 2NM)

I don't necessarily disagree with you, although that pressure was as of when it was classified as a cat. 3. Of course I do realize that 981 is still way too high for a cat. 3. It definitely looks fishy, and that's the main reason I posted about it.

[tallywx]

I love the advisories from 1960. For one of the public advisories on Ethyl, the following is stated:

"The following statement has been issued by the New Orleans Weather Bureau to stop Rumors of another tropical storm. There is no tropical storm development in the Gulf of Mexico other than Hurricane Ethyl at the present time."

I also found a recon. report from the 14th of that month at 2006z, which states that the eye was at 26.0N, 89' 58" W. Max. observed surface winds were 130 kts at 600 feet with the circular eye ill defined. Pressure was at 972 mb at the time.

So clearly, they used a 100% calculation of 600 feet, which is grossly misguided. A standard reduction I believe would yield 90 kts, or a category 2 storm.

[tallywx]

Another Ethyl recon. report:

At 2307z on the 14th, 140kt winds were ESTIMATED in all quadrants. Storm centered at 26' 38"N, 89' 16" W. Circular eye well defined 10 mi in diameter. Wind eye 30 miles in diameter (concentric eyewalls?). SLP measurement of 976 MB. 9 degree rise in temp. through the eyewall. Seas were 35 feet.


Then, a bit later, at 40 mi east of the eye, winds were clocked at 100 kts.

For that entire recon. flight, the lowest pressure measured was 972 mb. After that, the eye started to become an ellipse with various mesoscale features breaking off, a sign of weakening.
------------
Something is definitely wrong here, folks. No storm with a 976 mb pressure could produce winds at ANY FLIGHT LEVEL approaching 140 kts.

[tallywx]

Sorry for the continued posts, but the incompetence of the science just a few short decades ago is unbelievable.

At the same time that Ethyl was producing category 5 winds with a 972 mb pressure, NWS Tallahassee issued a local statement predicting that the storm would trend toward the northeast and bring hurricane force winds to the city by 3 a.m. This was about six hours before the storm moved NW toward Mississippi. So a six-hour forecast error of 300 miles. Insane.

[sponger]

Well it was the 60's! Maybe they were smoking something funny!!!

[x-y-no]

Sorry for the continued posts, but the incompetence of the science just a few short decades ago is unbelievable.

At the same time that Ethyl was producing category 5 winds with a 972 mb pressure, NWS Tallahassee issued a local statement predicting that the storm would trend toward the northeast and bring hurricane force winds to the city by 3 a.m. This was about six hours before the storm moved NW toward Mississippi. So a six-hour forecast error of 300 miles. Insane.

Maybe proximity to hurricane "Ethyl" had made tham drunk?

Seriously, though, by comparison to recent years the tools available in 1960 were incredibly primitive. No sattelites, very sparse upper air observations, sparse surface observations outside of the populated areas of the continental landmasses, no numerical models at all, etc. I'm not even sure what methodology they had available for estimating flight level winds in those days ... it's easy to be critical, but they had a heck of a lot more unknowns back then.

Jan

[MGC]

To estimate winds they looked at the wave height. They didn't have the fancy instruments of today. Recon was still in its infancy.....MGC

[Hurricanehink]

I would guess when re-analysis gets there it will be lowered a lot, possible only maxing at Cat. 2.

[HURAKAN]

[img]ftp://ftp.nhc.noaa.gov/pub/storm_archives/atlantic/prelimat/atl1960/ethel/prelim.gif[/img]

[img]ftp://ftp.nhc.noaa.gov/pub/storm_archives/atlantic/prelimat/atl1960/ethel/prelim01.gif[/img]

Something that doesn't fit correctly with the information, 140 knots and 972 mb? That's extremely high for a cat. 5 hurricane.

[HurricaneBill]

When Ethel made landfall, she was a upper end Category 1. Sustained winds of 90 mph were recorded.

My guess is that Ethel quickly strengthen to a upper end Cat 2/ possibly low end Cat 3, but was disorganized, so she weakened. Probably a similar situation as to what happened to Opal and Lili.

[HURAKAN]

You never know where you will end up in life. The reanalysis of Ethel is done and several changes have been made to the track and intensity. Can't tell them all but Ethel is not a category 5 hurricane anymore. The maximum intensity has been reduced and genesis is now over a day earlier. I imagine that the hurricane committee will have an interesting time working on this hurricane.

[TropicalAnalystwx13]

If I remember correctly, the 140kt winds that bumped Ethel to Category 5 intensity were measured at flight-level; this would mean the storm was a Category 4 hurricane. Still, it's strange that the pressure was so high.

[mrbagyo]

Something that doesn't fit correctly with the information, 140 knots and 972 mb? That's extremely high for a cat. 5 hurricane.

that sounds ??? - how can a cat 5 hurricane have a MSLP of just 972... well it's in the 60's after all.

a lot worse here in WPAC I believe... Typhoon Della(1952) a category 5 - accdg. to JTWC it attained its peak intensity of 150 knots while over land after traversing the Sierra Madre Mountains of Luzon...seriously?? it rapidly intensified while over land??? JMA puts the pressure at 980 mb!!!

best track of Della
14 18.20 121.20 11/25/12Z 150 - SUPER TYPHOON-5

[brunota2003]

Using 140 knots from flight level, reductions ranging from 70% to 90% yield winds between 98 knots and 126 knots. Given that I don't know the structure of the storm, and what the reduction from 600 ft to surface would be (current flights fly at 5,000+ ft)...I would, personally, go with the middle ground and place the system at 110 knots for it's peak intensity.

[Cyclenall]

You never know where you will end up in life. The reanalysis of Ethel is done and several changes have been made to the track and intensity. Can't tell them all but Ethel is not a category 5 hurricane anymore. The maximum intensity has been reduced and genesis is now over a day earlier. I imagine that the hurricane committee will have an interesting time working on this hurricane.

What is the meaning of the bolded part? Are you somehow connected to the reanalysis of Hurricane Ethel? At no point did anyone think this was a CAT5 that I have read about.

a lot worse here in WPAC I believe... Typhoon Della(1952) a category 5 - accdg. to JTWC it attained its peak intensity of 150 knots while over land after traversing the Sierra Madre Mountains of Luzon...seriously?? it rapidly intensified while over land??? JMA puts the pressure at 980 mb!!!!!!

Never seen that one, a category 5 over some mountains . Looks like it loved landmass more than water based on that track.

[HurricaneBill]

Could the 140KT winds have been in a mesovortex?

[Hurricane Jed]

The Weather Bureau back then goofed on its intensity. I've read that several tropical cyclones throughout the 40's, 50's and 60's had their intensities overestimated.

[tolakram]

What is the meaning of the bolded part? Are you somehow connected to the reanalysis of Hurricane Ethel? At no point did anyone think this was a CAT5 that I have read about.

He works at the NHC.

http://www.nhc.noaa.gov/qa/201311_sandy_delgado.php