Quiet Atlantic; more on Supertyphoon Saomai

By: Dr. Jeff Masters , 2:11 PM GMT on August 11, 2006

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High wind shear continues to dominate the tropical Atlantic, and there's little to be concerned with today. The remains of the tropical wave that the Hurricane Hunters investigated earlier this week as it moved through the Lesser Antilles Islands are just south of Haiti. A hint of a circulation at mid levels of the atmosphere developed this afternoon, but the associated heavy thunderstorm activity is limited. The wave is under about 10-20 knots of wind shear, and any development of this system will be slow.

Supertyphoon Saomai:
In China, the death toll has risen to over 100 in the wake of Supertyphoon Saomai, which slammed into the coast south of Shanghai Thursday as a Category 4 storm with 135 mph winds. The death toll will no doubt rise higher today as the remains of Saomai spread heavy rains through the same region of China hit by Tropical Storm Bilis, which killed more than 600 people last month.


Figure 1. Supertyphoon Saomai as it passed north of Taiwan, August 10, 2006 at 1:22 GMT. At maximum strength, Saomai was a Category 5 storm with 160 mph winds. The image was taken by the Department of Defense F-15 satellite. Image credit: NOAA Environmental Visualization Project.

The media is calling Saomai the worst typhoon to hit China in 50 years, but there is some dispute about just how strong the storm was at landfall. Here is comparison of intensities from three different agencies at Saomai's landfall at 12 GMT August 10:

U.S. Joint Typhoon Warning Center: 1-min sustained winds of 135 mph, Cat 4.
Japan Meteorological Agency: 1-min sustained winds of 100 mph, Cat 2.
Hong Kong Observatory: 1-min sustained winds of 115 mph, Cat 3.

So, these three agencies all using the same satellite data couldn't agree on the strength of this typhoon within two Saffir-Simpson categories! This underscores the difficulty of trying to determine if global warming is causing an increase in Category 4 and 5 hurricanes--even today with much better tools and training, experts still can't agree on storm intensities with the accuracy needed for such a study.

This was discussed in more detail in a paper published this year by Kamahori, Yamazaki, Mannoji, and Takahashi of the the Japan Meteorological Agency (JMA) in the on-line journal Scientific Online Letters on the Atmosphere - a new journal produced by the Meteorological Society of Japan. The study compares typhoon intensities in the Northwest Pacific since 1977 as compiled by the Joint Typhoon Warning Center (JTWC) and the JMA. The JTWC data was used in the famous Webster et. al study from 2005 that found a worldwide 80% increase in Category 4 and 5 tropical cyclones since 1970. A key element of their conclusions was the data from the Northwest Pacific, which make up about 50% of global Category 4 and 5 storms. The JMA group found that using JTWC's dataset, the number of days when a Category 4 or 5 typhoon was present increased from about 10 per year in 1977-90, to 17 per year during 1991-2004--a 70% increase. However, the JMA data for the same time period showed a 40% decrease in Category 4 and 5 typhoon days. The authors concluded, "We do not have sufficient evidence to judge which dataset is reasonable." I would have to agree--until we get a coordinated major re-analysis effort of all the tropical cyclone data for the globe, it is dangerous to make conclusions about whether global warming is causing an increase in tropical cyclone intensities. I think it is likely there has been some increase, but it is nowhere nearly as large as the 80% increase reported by Webster et. al.

Jeff Masters

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707. IKE
1:45 PM GMT on August 12, 2006
Dr. M has a new blog.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
697. StormJunkie
1:20 PM GMT on August 12, 2006
So the NAM and the Eta are the same?
Member Since: August 17, 2005 Posts: 26 Comments: 16874
694. IKE
1:16 PM GMT on August 12, 2006
Dry air w/dew points in the 70's. The dry air must be in the mid/upper levels?
Member Since: June 9, 2005 Posts: 23 Comments: 37860
691. IKE
1:08 PM GMT on August 12, 2006
I saw Dr. M's update on here yesterday afternoon at 3:10 CDST.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
690. IKE
1:07 PM GMT on August 12, 2006
GS said>>>But those hot spicey Carribean girls usually do not put on a lot of weight.... no fat ladies singing yet!....that's funny!

They sure do here! Must not be many fast-food joints down there..........
Member Since: June 9, 2005 Posts: 23 Comments: 37860
689. IKE
1:05 PM GMT on August 12, 2006
On WV I see a spin SSE of Jamaica. I also see that pesky ULL east of the southern Bahamas.

What I don't understand is why the clouds associated with the former 91L..just vanished? I'm glad, but I don't get it.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
687. IKE
12:59 PM GMT on August 12, 2006
Not sure what the dgex is...maybe turtlehurricane knows....

Member Since: June 9, 2005 Posts: 23 Comments: 37860
686. StormJunkie
12:58 PM GMT on August 12, 2006
lol Rand, that is why I think it is an area that bears watching a little closer then the normal blob.
Member Since: August 17, 2005 Posts: 26 Comments: 16874
685. IKE
12:58 PM GMT on August 12, 2006
Posted By: GulfScotsman at 7:54 AM CDT on August 12, 2006.
Posted By: IKE at 12:32 PM GMT on August 12, 2006.
91L....GONE!!!!!!!!!!!

The ghostly well defined mid-low VORTEX remains in tact and very symetrical.

you cannot see it.... but it is there!


OMG!!!!!!!!!

Keep an eye on it.

Darn thing just vanished!
Member Since: June 9, 2005 Posts: 23 Comments: 37860
684. StormJunkie
12:57 PM GMT on August 12, 2006
So what is the dgex? That is a new one to me
Member Since: August 17, 2005 Posts: 26 Comments: 16874
683. salter
12:54 PM GMT on August 12, 2006
IKE
what is the ( dgex )i've never heard of that.
678. IKE
12:48 PM GMT on August 12, 2006
Per Tampa's morning discussion......On Wednesday the model solutions are becoming more divergent in the
latest runs. Both GFS and dgex keep the remnant moisture from the
dissipated front over the southern half of Florida through Thursday
while also depicting a second frontal boundary forming over the
central states. This new front begins dropping southward by
Wednesday evening. GFS solution is more conservative and brings this
second boundary into northern Florida by Friday early in the
morning. Dgex moves the front faster and brings it over northern and
central Florida by Thursday morning thus combining with the
lingering low level moisture and suggesting good chances of rain
everywhere. Also...the front looks more vigorous on dgex while GFS
depicts a more weaker system barely reaching the northern half of
the County Warning Area. Also...a low level cyclone is shown on both models forming
just east of Florida with dgex again spinning it faster and stronger
than GFS. At this point the forecast will continue to follow the GFS
solution and keeping basically climatology probability of precipitation through Friday and wait
for later model runs to see if GFS begins trending towards the more
aggressive solution shown by dgex.

Member Since: June 9, 2005 Posts: 23 Comments: 37860
675. IKE
12:39 PM GMT on August 12, 2006
SJ...the NAM has 2 lows east of Florida in 84 hours..one east of Miami and another..stronger one...1008 mb..east of about JAX...looks like it has it heading toward the Carolinas.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
673. IKE
12:37 PM GMT on August 12, 2006
Posted By: salter at 7:34 AM CDT on August 12, 2006.
morning all
IKE that would be a nice thought. i live in FL and the insurance companys would still find away to raise rates. IMHO


Tell me about it....I'm in the panhandle...my rates are awful.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
672. StormJunkie
12:36 PM GMT on August 12, 2006
Well Rand, with an unformed system I doubt they willever say the same thing, but what I find interesting is that several runs have formed something on the tail of this front, as well as the Nogaps at times. And now the fact that the GFS hinted a possible push back to the W in earlier runs, but that is much more evident in the latest run. Just thought it was interesting. Not worth too much yet, execept as an area to keep an eye on.

Member Since: August 17, 2005 Posts: 26 Comments: 16874
671. salter
12:34 PM GMT on August 12, 2006
morning all
IKE that would be a nice thought. i live in FL and the insurance companys would still find away to raise rates. IMHO
670. ricderr
12:34 PM GMT on August 12, 2006
very true.....remember after jean heading south to find a place to eat
Member Since: June 27, 2006 Posts: 676 Comments: 22382
669. IKE
12:32 PM GMT on August 12, 2006
91L....GONE!!!!!!!!!!!

Tropics are quiet.

Day 73....110 to go and it's over.

May the shear stay with us...maybe we can go all year without a hurricane in the Atlantic.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
667. ricderr
12:30 PM GMT on August 12, 2006
ok...turned the light on...much easier to see the keyboard...rand...what i was trying to say was...your pizza joint any good?
Member Since: June 27, 2006 Posts: 676 Comments: 22382
665. ricderr
12:23 PM GMT on August 12, 2006
good morning boys and girls.....rand..saw tyou say pizza...food of the gods....have yet to dind the "best" place yet...you're any good?
Member Since: June 27, 2006 Posts: 676 Comments: 22382
664. StormJunkie
12:22 PM GMT on August 12, 2006
Morning ya'll:)

Anyone check the 06zGFS yet? Still wants to form a system on the tail end of the E coast trough. Now it is hinting at a possible move back towards the N Fla to Obx coast.
Member Since: August 17, 2005 Posts: 26 Comments: 16874
659. turtlehurricane
12:05 PM GMT on August 12, 2006
I dont think upper lows can "pull in" surface features, it may have sheared it towards the center of the upper low giving it the appearence it was pulling in 91L.
Member Since: July 22, 2005 Posts: 227 Comments: 469
657. turtlehurricane
11:57 AM GMT on August 12, 2006
Well tropics are quiet again, only 2 areas worth mentioning in the newly updated

Tropical Weather Roundup

Another good and quiet day!
Member Since: July 22, 2005 Posts: 227 Comments: 469

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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