Postcards II: hurricane database issues, and the Bill Gray show

By: Dr. Jeff Masters , 5:24 PM GMT on April 29, 2008

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I'm in Orlando this week for the 28th Conference on Hurricanes and Tropical Meteorology, sponsored by the American Meteorological Society. The conference, held once every two years, brings together the world's experts on hurricane science. A few snapshots from the past 24 hours:

Northern Hemisphere tropical cyclone inactivity in 2007
Ryan Maue of Florida State University showed that tropical cyclone activity in 2007 the Northern Hemisphere (Atlantic, Eastern Pacific, Western Pacific, and North Indian Oceans) was at its lowest level since 1977. The Accumulated Cyclone Energy (ACE) is calculated by summing the squares of the estimated maximum sustained velocity of every active tropical storm (wind speed 35 knots or higher), at six-hour intervals. The numbers are usually divided by 10,000 to make them more manageable.

For the Atlantic in 2007, the season's ACE index was 68, 31% below the average of 96. For comparison, the Hurricane Season of 2005 had an ACE of 248. A single storm of the 2004 hurricane season--Hurricane Ivan--had an ACE of 70, more than the ACE index for the entire 2007 hurricane season. For the Northern Hemisphere as a whole, 2007 had the lowest ACE value since 1977. The North Indian Ocean was the only Ocean basin in the Northern Hemisphere that had an above-average ACE in 2007:

Ocean Basin....2007 ACE..Average ACE..%change
-------------------------------------------------------------------------
Atlantic .............68.........96.........-31%
E. Pacific............52........132.........-60%
W. Pacific...........209........303.........-31%
N. Indian.............44.........16........+275%
N. Hemisphere..376........551.........-31%

Uncertainties in the hurricane data base
HURDAT, the official Atlantic hurricane database, has many significant errors that are slowly being corrected, thanks to a major re-analysis effort being led by Dr. Chris Landsea of the National Hurricane Center. For example, HURDAT lists the Great New England Hurricane of 1938 as a Category 2 extratropical storm (85 knots) at landfall on Long Island, when it was really a Category 3 hurricane with 105 knot winds. Dr. Landsea presented the results of the re-analysis of 12 major hurricanes that hit the U.S. Nine of these 12 storms, including the 1938 hurricane, were re-analyzed to have higher winds at landfall. Dr. Landsea cautioned that our knowledge of past storms in the 1950s and 1960s is quite poor, compared to current capabilities. This occurs despite the fact the hurricane hunters were flying. For example, Hurricane Wilma of 2005 had 280 measurements of its maximum intensity, while Hurricane Carol of 1954, a Category 3 storm that hit North Carolina, had only seven. There were hurricane hunter flights into Carol, but they usually did not fly into the eyewall. It was common for the hurricane hunters to only get close enough to the center to estimate the position using radar back in those days. Carol stalled off the coast of North Carolina for four days, during which time no hurricane hunter flights penetrated into the eye. Could Carol have intensified into a Category 5 storm during that time? We'll never know. Because of such uncertainties, making estimations of trends in Atlantic hurricanes based on HURDAT is difficult to do, Dr. Landsea cautioned.

The Bill Gray show
Dr. Bill Gray of Colorado State University, as usual, generated the most laughter. He commented that he had been to all 28 of these AMS hurricane conferences, with the exception of the first (he was in grad school) and the fourth, when he was in Tokyo. Dr. Gray presented an educational talk, emphasizing the role of natural decades-long cycles in the salinity changes in the Atlantic as being the primary driver of observed increases in Atlantic hurricane activity in recent years. He showed that during 1945-1969 (25 years), during a period the globe was cooling slightly, there were three times as many intense hurricanes in the Atlantic compared to the 25 year period 1970-1994--a period the globe warmed significantly. His tongue-in-cheek conclusion: "CO2 gets into these storms and squashes them!" Extending this result to landfalling U.S. hurricanes, one could claim that we should expect zero landfalling U.S. hurricanes by 2050. Dr. Gray cautioned that this ridiculous result showed that one can manipulate statistics to show virtually any result you want.


Figure 1. Tounge-in-cheek misuse of statistics by Bill Gray to show that the historical record of U.S. landfalling hurricanes predicts zero landfalling hurricanes in the U.S. by 2050 as a result of increasing CO2 in the atmosphere.

Contribution of increases in SST to Atlantic hurricane activity
Adam Lea of University College London presented results showing that the 0.27°C increase in Sea Surface Temperature(SST) between 1996 and 2005 in the Main Development Region (MDR) for hurricanes in the tropical Atlantic was responsible for a 40% increase in hurricanes and intense hurricanes in the Atlantic.

The benefits of hurricanes: rainfall in the Southeast U.S.
David Knight of the University of Virginia showed that hurricanes and tropical storms form an important part of the water budget in the Southeastern U.S. For example, up to 15% of the total rainfall in eastern South Carolina and North Carolina during the six months of hurricane season (June-November) was due to tropical storms or hurricanes between 1980-2004. These numbers are 10-14% for Florida, and 8-10% for Atlanta.

More postcards tomorrow!

Jeff Masters

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302. pearlandaggie
12:15 AM GMT on May 01, 2008
here's an interesting coincidence:
(from above)
"Ryan Maue of Florida State University showed that tropical cyclone activity in 2007 the Northern Hemisphere (Atlantic, Eastern Pacific, Western Pacific, and North Indian Oceans) was at its lowest level since 1977."

from Link
"Here is a short history of PDO phase shifts:

In 1905, PDO switched to a warm phase.
In 1946, PDO switched to a cool phase.
In 1977, PDO switched to a warm phase."

hmmmmm......
Member Since: September 14, 2007 Posts: 3 Comments: 3963
301. weathermanwannabe
5:19 PM GMT on April 30, 2008
"The warmest waters relative to normal will be in the northern areas of the Atlantic, especially toward the North American continent. This could potentially increase the threat of major landfalls to the U.S. coast."

"In determining areas of elevated potential for landfall, we try to understand where the spread of storm tracks will center - but even within this spread, storms can 'bunch', creating discrete areas of increased risk," Bastardi said. Last season, the spread of the storms shifted southwest with one such bunch in the northern Caribbean. "This year, early indications show that the spread will move north and east with a target closer to the Southeast U.S."


Not criticizing Bastardi; Just making the observation as to how inaccurate, and potentially useless, these early season long term predictions can be...........Interesting to me how he predicted, at this same time last year, a high risk for the Northern Gulf, and now after the fact, he is acknowledging somehow (without acknowledging to any fault per se) that his prediction just "shifted" southwest (a la Felix and Dean)........Guess they have to do some kind of "pre-season" outlook, but, I agree with Dr. M that most of us shuold not pay too much attention to these early outlooks because of the April Predictability Barrier...............


Member Since: August 8, 2006 Posts: 0 Comments: 9329
300. moonlightcowboy
4:00 PM GMT on April 30, 2008
Hello, lilfish! I was asking about you the other day! I was wondering when our expert lil bugger spotter was gonna show up! Good to see you back. How are you?
Member Since: July 9, 2006 Posts: 184 Comments: 29610
299. littlefish
3:44 PM GMT on April 30, 2008
My goodness, been awhile since I popped in here but figured I would stick a toe in the water early this Atlantic cyclone season and sau hello to all. Hope all are well and those in areas with potential cyclone activity are prepared and safe this season!
298. moonlightcowboy
3:24 PM GMT on April 30, 2008
GOM looks so quiet, peaceful.

Photobucket

Click on picture for larger view.


Member Since: July 9, 2006 Posts: 184 Comments: 29610
297. mgreen91
3:23 PM GMT on April 30, 2008
Joe Bastardi's Early 2008 Hurricane Forecast
Posted 2008-04-25
Slightly More Storms than Average with Increased Chances for Landfalls in North America

AccuWeather.com Hurricane Center meteorologists, led by Chief Long-Range and Hurricane Forecaster Joe Bastardi, have released a preliminary hurricane season forecast for 2008. They believe the waning La Niña conditions and a continued warm water cycle in the Atlantic Basin will be the two defining factors influencing the 2008 hurricane season, causing the number of storms to be slightly above average but, more importantly, increasing the chance for U.S. landfalling storms.

"The warming is not uniform across the entire Atlantic. In some areas where hurricanes normally form - the central and eastern tropical Atlantic - ocean water temperatures are near or below normal. This should limit the number of storms, so we do not expect a near record high number like in the 2005 season. However, considering other factors, the number of storms should be slightly higher than historical averages", said Bastardi. "The warmest waters relative to normal will be in the northern areas of the Atlantic, especially toward the North American continent. This could potentially increase the threat of major landfalls to the U.S. coast."

"In determining areas of elevated potential for landfall, we try to understand where the spread of storm tracks will center - but even within this spread, storms can 'bunch', creating discrete areas of increased risk," Bastardi said. Last season, the spread of the storms shifted southwest with one such bunch in the northern Caribbean. "This year, early indications show that the spread will move north and east with a target closer to the Southeast U.S."

Bastardi and the AccuWeather.com Hurricane Center are looking at 1955, 1996, and 1999 as a few of the years showing similar weather characteristics to our current large-scale patterns. In 1955, Hurricanes Connie and Diane hit the Outer Banks and Carolina Beach in North Carolina. In 1996, Hurricane Bertha made landfall near Wilmington and Hurricane Fran made landfall near Cape Fear in North Carolina. During the 1999 hurricane season, Floyd and Dennis made landfall in September on the North Carolina coast.

Bastardi will provide more details and insight at the AccuWeather.com Hurricane Summit on May 12, 2008 in Houston, TX. Attendees at the summit will include leaders in industries heavily impacted by tropical weather, Bastardi's AccuWeather.com EnergyPro® clients, and leading members of the press.

Member Since: August 4, 2006 Posts: 0 Comments: 290
295. OrchidGrower
2:45 PM GMT on April 30, 2008
For HIEXPRESS, re:

Strange this says Frederick was a Cat 3 at landfall, but the tab data says Cat 4.

Looks like it did intensify rapidly over the loop current.


from Pg. 1 of the current blog. Thanks for your followup to my comment about Hurricane Frederic. I noticed that the graphic also lists no U.S. deaths with that storm either, but in fact two people died (a child crushed inside an overturning mobile home, and a woman who drowned in a harbor).

And for IVANSURVIVOR, I agree with your comment about heightened violence in rapidly intensifying hurricanes. A neighbor of ours who stayed watched 2 tornadoes roll through our property that night before she fainted with fear. The complete deforestation of our community seemed to change the weather pattern thereafter, too, as we started seeing tornadoes in our community (small, F0, F1 and F2 types) with thunderstorms in the years that followed.

Discover magazine just put out a special "Better Planet" issue, that includes a brief article on particulate pollution being shown to increase t-storm violence but decrease rainfall. Study authors say the next step is to examine whether particulate pollution may have a link to increased tornado frequency. I have a theory why that indeed may be the case.
Member Since: September 24, 2002 Posts: 0 Comments: 394
294. Patrap
2:36 PM GMT on April 30, 2008
I Bet Dr. Masters is enjoying the Presentations at the Conference.They have quite a lot of them and workshops too.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
293. pearlandaggie
2:33 PM GMT on April 30, 2008
thanks, vortfix!
Member Since: September 14, 2007 Posts: 3 Comments: 3963
290. pearlandaggie
2:27 PM GMT on April 30, 2008
288. that's a really cool graphic. is there one for the Texas coast? it might come in handy for finding thermoclines while offshore fishing...
Member Since: September 14, 2007 Posts: 3 Comments: 3963
289. moonlightcowboy
2:25 PM GMT on April 30, 2008
Pat, just FYI, I dropped Dr. Masters some mail on the Vortrac Dopplar radar that we chin-wagged about yesterday. Hopefully, we'll see him say something about it soon.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
287. pearlandaggie
2:14 PM GMT on April 30, 2008
to my knowledge, that study has not been discounted yet. additionally, the discounted study dealt with satellite or some other method of temperature recording and there was a calibration error...this study includes direct temperature measurements from robots in the ocean (granted, a calibration issue could still be a problem, but that has not been mentioned yet).
Member Since: September 14, 2007 Posts: 3 Comments: 3963
286. Patrap
2:13 PM GMT on April 30, 2008
Latest Weekly Color Coded Hurricane Areas,LSU EarthScan Lab Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
285. moonlightcowboy
2:08 PM GMT on April 30, 2008
279. pearlandaggie 9:01 AM CDT on April 30, 2008
apeaking of preparedness, what's in your hurricane preparedness kit?

Pearland, Hurricanecrab has also got a good preparedness blog, too.

This year, he's also got a sort of "point-system" blog to tell how prepared you are. I fell short myself, scored above 200, so I have some additional things to do, too. But, check it out, too. It's a good blog.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
283. Patrap
2:05 PM GMT on April 30, 2008
Thanx guys...,
I never want to see the bad days that befell so many in 04-05 again.
Preparation is the Key to weathering the events to come.
And they will come,unfortunately.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
279. pearlandaggie
2:01 PM GMT on April 30, 2008
apeaking of preparedness, what's in your hurricane preparedness kit?
Member Since: September 14, 2007 Posts: 3 Comments: 3963
278. moonlightcowboy
1:59 PM GMT on April 30, 2008
Amen, Pat!

Gotta love, Patrap! Every year this guy stresses "preparedness" and I appreciate it. It's the thing to do. And, it bothers me that apathy comes into play - inactive seasons contribute to people letting their guard down, etc. And, then, wham - they get slammed - not prepared.

Pat's got a great blog on "preparation!" If you haven't checked it out, you should, and start getting a plan together.
Member Since: July 9, 2006 Posts: 184 Comments: 29610
276. CaneAddict
1:57 PM GMT on April 30, 2008
Good morning Cowboy!
You're sounding more "Fudd" like every day...LOL


I posted it Cane as a slight reminder that there ain't nothing happening in the Atlantic Basin right now.


Oh, Alright i gotcha. But that is rather normal right now...
Member Since: October 5, 2007 Posts: 3 Comments: 2151
275. pearlandaggie
1:53 PM GMT on April 30, 2008
266.

if the oceans are actually absorbing heat, then the temperature should be going up

Q=m*Cp*dT

(unless, of course, the oceans disobey the laws of thermochemistry)

Link
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274. moonlightcowboy
1:53 PM GMT on April 30, 2008
CA, just making a reference to Vort's "current" map - doesn't mean the "season" itself will be quiet. Relax, time will tell for sure. And, I sure hope it is quiet, but with neutral conditions, that's probably not the likelihood - so, maybe we can just hope for "fish" storms!!!
Member Since: July 9, 2006 Posts: 184 Comments: 29610
273. Patrap
1:52 PM GMT on April 30, 2008
Be Prepared aint just a Boy Scout Motto...

History teaches that a lack of hurricane awareness and preparation are common threads among all major hurricane disasters. By knowing your vulnerability and what actions you should take, you can reduce the effects of a hurricane disaster. Hurricane Preparedness Week during 2008 will be held May 25th through May 31st.

The goal of this Hurricane Preparedness Web site is to inform the public about the hurricane hazards and provide knowledge which can be used to take ACTION. This information can be used to save lives at work, home, while on the road, or on the water.
Link
Member Since: July 3, 2005 Posts: 426 Comments: 129093
272. CaneAddict
1:51 PM GMT on April 30, 2008
269. HouseofGryffindor 1:49 PM GMT on April 30, 2008
It seems to me like this will be a very dangerous year for hurricanes, and from what I can tell, many of those may make landfall in the U.S., or come pretty close.


Yes it does....
Member Since: October 5, 2007 Posts: 3 Comments: 2151
271. moonlightcowboy
1:51 PM GMT on April 30, 2008
LOL, Vort. Feel more "Fuddy," too! Should've thrown another w in vewy qwiet! lol

- STL, #220, #266 are nice posts.
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270. CaneAddict
1:51 PM GMT on April 30, 2008
264. moonlightcowboy 1:44 PM GMT on April 30, 2008
Good morning, Vort. Season looks vewy quiet right now.

- WWB, CA, of course it takes much more than warm SST's for activity. Each season, SST's are going to be warm. I suppose we follow that to how early they do warm, or wane. Several other things must also fall into place for tropical development. I certainly hope the season is relatively quiet and "fish" is the word for the season. Another month to


Refer back to my last post....where i mentioned all the things that are setting up...How does this season look like it will be very quiet?
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264. moonlightcowboy
1:44 PM GMT on April 30, 2008
Good morning, Vort. Season looks vewy quiet right now.

- WWB, CA, of course it takes much more than warm SST's for activity. Each season, SST's are going to be warm. I suppose we follow that to how early they do warm, or wane. Several other things must also fall into place for tropical development. I certainly hope the season is relatively quiet and "fish" is the word for the season. Another month to go as Vort points out - so, we wait, we see!
Member Since: July 9, 2006 Posts: 184 Comments: 29610
263. CaneAddict
1:42 PM GMT on April 30, 2008
Good morning all....and happy last day of April!

We still have a month before that product resumes....why did you post it?
Member Since: October 5, 2007 Posts: 3 Comments: 2151
261. CaneAddict
1:36 PM GMT on April 30, 2008
258. moonlightcowboy 1:32 PM GMT on April 30, 2008
WWB, I don't think they're going to get substantially cooler.


2 Words, BAD NEWS!
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260. weathermanwannabe
1:36 PM GMT on April 30, 2008
258. moonlightcowboy 9:32 AM EDT on April 30, 2008
WWB, I don't think they're going to get substantially cooler.


Yo se....I would not make any plans to go to Cancun & Cozumel this Summer durng the peak of the season........
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259. CaneAddict
1:35 PM GMT on April 30, 2008
Based on the many things currently i would say we will have an early storm and a very busy season. Seems way too many indicators pointing the same direction......JUst my opinion.

Things such as:
Increasing SST's
Decreasing Shear
Increasing TCHP
Setting up of the A/B High
Steering currents
Most of all the fact that this season for the most part at least will be under NEUTRAL conditions, That marks for a very active season. Take a look at past neutral seasons, They are always the most busy, Such as 2005 ( I KNOW WERE NOT GOING TO HAVE ANOTHER 2005)

So yes we are in for a busy year, Most likely more busy then 2006-2007 for sure!
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258. moonlightcowboy
1:32 PM GMT on April 30, 2008
WWB, I don't think they're going to get substantially cooler.
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257. TexasGulf
1:32 PM GMT on April 30, 2008
Actually, I was just wanting to plant the suggestion so we can watch 100,000 Global Warming activists trying to not exhale for an hour. Should make for some interesting video.

That "Take a Breather from CO2 Emmissions" day was purely a joke. If you are a gullible GW activist, please don't try to hold your breath for an hour.
Member Since: April 28, 2008 Posts: 0 Comments: 354
256. weathermanwannabe
1:31 PM GMT on April 30, 2008
247. moonlightcowboy 9:21 AM EDT on April 30, 2008

That's a pretty warm pool of water in the Yucatan Channel (the GS loop current) right now.....Could mean some real trouble later on if it is still there come July.......
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255. TampaSpin
1:30 PM GMT on April 30, 2008
Based on the many things currently i would say we will have an early storm and a very busy season. Seems way too many indicators pointing the same direction......JUst my opinion.
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253. CaneAddict
1:27 PM GMT on April 30, 2008
Looks like based on those SST maps moonlight posted that the Atlantic over all is really heating up ESPECIALLY in the Caribbean! Akso as a whole it looks about the same as 2004 in terms of SST's.
Member Since: October 5, 2007 Posts: 3 Comments: 2151
252. pearlandaggie
1:26 PM GMT on April 30, 2008
AGW and related taxation aside, I'm more concerned with agriculture. Think of the agricultural explosion witnessed in California during the last 30 years (and subsequent warm phase of the PDO). I hope cooler weather doesn't significantly impact the agricultural productivity in California, but somehow that seems logically inconsistent...
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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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