More pre-season predictions of a very active Atlantic hurricane season

By: Dr. Jeff Masters , 3:02 PM GMT on July 12, 2010

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Hello again, it's Jeff Masters back again after a week away. Well, the past week was a wicked hot time to be in New England, where I was vacationing, and I certainly didn't expect to see 98° temperatures in Maine like I experienced! Fortunately, it's not hard to find cold water to plunge into in New England. Thankfully, the tropics were relatively quiet during my week away, and remain so today. There are no threat areas in the Atlantic to discuss at present, and none of the reliable computer models is forecasting tropical cyclone development over the next seven days. The NOGAPS model does show a strong tropical disturbance developing near the waters offshore of Nicaragua and Honduras this weekend, though. With not much to discuss in the present-day tropics, let's take a look at more pre-season predictions of the coming Atlantic hurricane season.

2010 Atlantic hurricane season forecast from Penn State
Dr. Michael Mann and graduate student Michael Kozar of Penn State University (PSU) issued their 2010 Atlantic hurricane season forecast on May 28. Their forecast utilizes a statistical model to predict storm counts, based on historical activity. Their model is predicting 19 to 28 named storms in the Atlantic, with a best estimate of 23 storms. The forecast assumes that record warm SSTs will continue in the Atlantic Main Development Region for hurricanes. Dr. Mann has issued two previous forecasts, in 2007 and 2009. The 2007 forecast was perfect--15 storms were predicted, and 15 storms occurred. The 2009 forecast called for 11.5 named storms, and 9 occurred (the 2009 forecast also contained the caveat that if a strong El Niño event occurred, only 9.5 named storms were expected; a strong El Niño did indeed occur.) So, the 2009 forecast also did well.


2010 Atlantic hurricane season forecast from the UK GloSea model
A major new player in the seasonal Atlantic hurricane season forecast game is here--the UK Met Office, which issued its first Atlantic hurricane season forecast in 2007. The UK Met Office is the United Kingdom's version of our National Weather Service. Their 2010 Atlantic hurricane season forecast calls for 20 named storms, with a 70% chance the number will range between 13 and 27. They predict an ACE index of 204, which is about double the average ACE index.

I have high hopes for the UK Met Office forecast, since it is based on a promising new method--running a dynamical computer model of the global atmosphere-ocean system. The CSU forecast from Phil Klotzbach is based on statistical patterns of hurricane activity observed from past years. These statistical techniques do not work very well when the atmosphere behaves in ways it has not behaved in the past. The UK Met Office forecast avoids this problem by using a global computer forecast model--the GloSea model (short for GLObal SEAsonal model). GloSea is based on the HadGEM3 model--one of the leading climate models used to formulate the influential UN Intergovernmental Panel on Climate Change (IPCC) report. GloSea subdivides the atmosphere into a 3-dimensional grid 0.86° in longitude, 0.56° in latitude (about 62 km), and up to 85 levels in the vertical. This atmospheric model is coupled to an ocean model of even higher resolution. The initial state of the atmosphere and ocean as of June 1, 2010 were fed into the model, and the mathematical equations governing the motions of the atmosphere and ocean were solved at each grid point every few minutes, progressing out in time until the end of November (yes, this takes a colossal amount of computer power!) It's well-known that slight errors in specifying the initial state of the atmosphere can cause large errors in the forecast. This "sensitivity to initial conditions" is taken into account by making many model runs, each with a slight variation in the starting conditions which reflect the uncertainty in the initial state. This generates an "ensemble" of forecasts and the final forecast is created by analyzing all the member forecasts of this ensemble. Forty-two ensemble members were generated for this year's UK Met Office forecast. The researchers counted how many tropical storms formed during the six months the model ran to arrive at their forecast of twenty named storms for the remainder of this hurricane season. Of course, the exact timing and location of these twenty storms are bound to differ from what the model predicts, since one cannot make accurate forecasts of this nature so far in advance.

The grid used by GloSea is fine enough to see hurricanes form, but is too coarse to properly handle important features of these storms. This lack of resolution results in the model not generating the right number of storms. This discrepancy is corrected by looking back at time for the years 1989-2002, and coming up with correction factors (i.e., "fudge" factors) that give a reasonable forecast.

The future of seasonal hurricane forecasts using global dynamical computer models is bright. Their first three forecasts have been good. Last year the Met Office forecast was for 6 named storms and an ACE index of 60. The actual number of storms was 9, and the ACE index was 53. Their 2008 forecast called for 15 named storms, and 15 were observed. Their 2007 forecast called for 10 named storms in July - November, and 13 formed. A group using the European Center for Medium Range Weather Forecasting (ECWMF) model is also experimenting with some promising techniques using that model. Models like the GloSea and ECMWF will only get better as increased computer power and better understanding of the atmosphere are incorporated, necessitating less use of "fudge" factors based on historical hurricane patterns. If human-caused climate change amplifies in coming decades, statistical seasonal hurricane forecasts like the CSU's may be limited in how much they can be improved, since the atmosphere may move into new patterns very unlike what we've seen in the past 100 years. It is my expectation that ten years from now, seasonal hurricane forecasts based on global computer models such as the UK Met Office's GloSea will regularly out-perform the statistical forecasts issued by CSU.

2010 Atlantic hurricane season forecast from Florida State University
Last year, another group using dynamical computer forecast models entered the seasonal hurricane prediction fray. A group at Florida State University led by Dr. Tim LaRow introduced a new model called COAPS, which is funded by a 5-year, $6.2 million grant from NOAA. This year, the COAPS model is calling for 17 named storms and 10 hurricanes. Last year's prediction by the COAPS model was for 8 named storms and 4 hurricanes, which was very close to the observed 9 named storms and 3 hurricanes.

Summary of 2010 Atlantic hurricane season forecasts
Here are the number of named storms, hurricanes, and intense hurricanes predicted by the various forecasters:

23 named storms: PSU statistical model
20 named storms: UKMET GloSea dynamical model
18.5 named storms, 11 hurricanes, 5 major hurricanes: NOAA hybrid statistical/dynamical model technique
18 named storms, 10 hurricanes, 5 intense hurricanes: CSU statistical model (Phil Klotzbach/Bill Gray)
17.7 named storms, 9.5 hurricanes, 4.4 intense hurricanes: Tropical Storm Risk (TSR), hybrid statistical/dynamical model technique
17 named storms, 10 hurricanes: FSU dynamical model
10 named storms, 6 hurricanes, 2 intense hurricanes: climatology

Only four hurricane seasons since 1851 have had as many as nineteen named storms, so 5 out of 6 of these pre-season forecasts are calling for a top-five busiest season in history. One thing is for sure, though--this year won't be able to compete with the Hurricane Season of 2005 for early season activity--that year already had five named storm by this point in the season, including two major hurricanes (Dennis and Emily.)

Tropical Storm Conson threatens the Philippines
Weather456 has an interesting post on why the Western Pacific typhoon season has been exceptionally inactive this year. It looks like we'll have out first typhoon of the Western Pacific season later today, since Tropical Storm Conson appears poised to undergo rapid intensification, and should strike the main Philippine island of Luzon as a Category 1 or 2 typhoon.

Next post
I'll have an update Wednesday.

Jeff Masters

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WARNING! JFV has returned yet again with the username "WSVN". Please ignore and report him immediately when he sign on to avoid any problems.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting Grothar:


He was one of those daguerreo types, if you know what I mean.


ouch. lol

but grothar, jokes is good. jokes is healthy. jokes clear our minds so we can think mighty thoughts and make mighty predictions. ....well... uh.... YOU can make mighty predictions.....
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1162. Grothar
Quoting earthlydragonfly:


LMAO Honor... I would like to thank the academy for this Badge of honor!! Woohooo... Back to what matters... Oil and Hurricanes


Don't forget to thank the little people on here. I was put on permanent ignore by someone here and I was complimenting them and they didn't realize it. I was sent a nasty WU mail. That is why I rarely compliment anybody. They might take is an an insult.
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1161. bappit
Quoting Bordonaro:

I also believe Hurricane Alex's name should be retired.

Well, one thing I've learned this summer on the blog is that Mexico would have to request the name be retired.
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1159. gator23
.
Quoting earthlydragonfly:
Why cant I read what Gator says??? Did I get blocked by him??? LMAO I have never been on someone's ignore list before.

I havent ignored you. Why would i?
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Quoting Bordonaro:
.
Your family here, people don't like it, they can go elsewhere.



yes sir
Member Since: May 21, 2006 Posts: 5091 Comments: 115439
Quoting beell:
RE: Alex Retirement:

From the Doc's blog. Post-Alex, July 2nd.

It is possible Alex will have its named retired, though I think it unlikely. One of the countries substantially affected by a hurricane must make a request to the World Meteorological Organization (WMO) to have the hurricane's name required. Mexico was the country most affected by Alex, and Mexico has been reluctant to make retirement requests in the past. For example, Mexico suffered two landfalls from Category 5 Hurricane Emily in 2005, yet did not request that Emily's name be retired; there will be a new storm named Emily next year.
They did request for Stan that same year to be retired, though. There was some very bad flooding with Stan and subtantial loss of life.

With Alex, I dunno. The flooding in places like Monterrey was quite surprising, and some of the post-storm deaths included some well-known public figures. They may actually consider it, depending on what happens the rest of this season.
Member Since: October 25, 2005 Posts: 19 Comments: 22687
Quoting Tazmanian:




well said
.
Your family here, people don't like it, they can go elsewhere.
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1155. bappit
Quoting beell:


Who could forget the "Golden Nature" series?!! I did make a quick check for pre-model forecasting guides. Zippo on the goat bones.

Bats Of The World
Gary Graham
1994

Butterflies And Moths
Robert Mitchell, & Herbert Zim
1962

Herbs And Spices
Julia Morton
1976

Pond Life
George Reid
1967

Hallucinogenic Plants
Richard Schultes
1976

Reptiles and Amphibians
Herbert Zim & Hobart Smith
1953

Spiders & Their Kin
Herbert & Lorna Levi
1968

Hallucinogenic plants? Cool!
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Quoting blsealevel:


Would this be winds at mid level?

850 is generally around 5000ft
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1153. Grothar
Quoting GeoffreyWPB:


Not a stretch...his baby pictures were taken by Mathew Brady.


Wouldn't have anything to do with him. He was one of those daguerreo types, if you know what I mean. :P

At least post a tropical image if you're going to insult someone. Only joking peoples. We should stay on topic.
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Quoting Bordonaro:


Out of deep respect for Taz, who adds many important things to our blog, folks, do not insult him PERIOD. He is very bright and adds things to this blog that even the professional meteorologist sometime miss.

This is a Tropical Weather Blog, not a Spelling Blog, not a Spelling Bee. Anyone who wants to bicker, please go hang out on another blog or internet media. Thanks!




well said
Member Since: May 21, 2006 Posts: 5091 Comments: 115439
1151. bappit
Quoting Chicklit:
So the folks in Louisiana have been failed by both a Republican and Democrat president.

I am still hearing you and others say that the Coast Guard passes the buck. That is disgraceful to the men and women of that service.
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Quoting Tazmanian:
1132. FLdewey 1:53 AM GMT on July 13, 2010 Hide this comment.

Quoting Tazmanian:
you guys skip right ovee commet 1096



We were trying not to notice you can't even spell NOSE. ;)



POOF



would any one like too joine him???



i will not have none of that


Out of deep respect for Taz, who adds many important things to our blog, folks, do not insult him PERIOD. He is very bright and adds things to this blog that even the professional meteorologist sometime miss.

This is a Tropical Weather Blog, not a Spelling Blog, not a Spelling Bee. Anyone who wants to bicker, please go hang out on another blog or internet media. Thanks!
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Someone must be paying ASCAT and WINDSAT to miss the areas I want to look at.
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Quoting Baltimorebirds:
Wow you put him on ignore faster than my grandma can chase after us.



yup
Member Since: May 21, 2006 Posts: 5091 Comments: 115439
Quoting GeoffreyWPB:


I consider it a badge of honor!


LMAO Honor... I would like to thank the academy for this Badge of honor!! Woohooo... Back to what matters... Oil and Hurricanes
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Quoting Grothar:


He wasn't as tall as one might think. His hat enhanced his appearance. Anything in the tropics of interest. I have been too busy to drop in today. Unlike some here, I have a life. LOL Boring, but it's all mine.
ROFL!
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting AustinTXWeather:
LOL
Taz, I'm glad you referenced it again b/c I did miss it. It's making me laugh -- probably mostly b/c I don't get it but welcome a good sense of humor. ;)



your welcome
Member Since: May 21, 2006 Posts: 5091 Comments: 115439


Would this be winds at mid level?
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1142. will45
when the man said let there be light Grothar threw the switch lmao
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LOL
Taz, I'm glad you referenced it again b/c I did miss it. It's making me laugh -- probably mostly b/c I don't get it but welcome a good sense of humor. ;)
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1140. Grothar
Quoting CybrTeddy:


Grothar's the best when it comes to tracking cyclones, he's been tracking them for years.. all the way back to the Lincoln administration. Ha kidding.


He wasn't as tall as one might think. His hat enhanced his appearance. Anything in the tropics of interest. I have been too busy to drop in today. Unlike some here, I have a life. LOL Boring, but it's all mine.
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Quoting FLdewey:
Obviously the BP disaster is just that, a disaster. The annoying thing about all of the talking heads on the 24hr networks (CNN, FOX, MSNBC, Etc) is they have to fill 24hrs with "news"! Inevitably they all simply provide material for the Daily Show and The Colbert Report. :-)

It's not like BP went to Home Depot yesterday and bought the new cap on the clearance rack. It took time to design it, fabricate and test it, and engineer a plan to install it at 5,000 feet below the gulf's surface. It's really quite a daunting task which hopefully will be completed sooner than later.
The problem with the BP gusher is not that they haven't been able to come up with solutions in the 3 months since April. It's that while drilling technologies have advanced so far that we can now successfully drill 1 mile under the sea surface, emergency procedures have stalled in the late 1970s. Other, wiser to this topic than I, have already expressed this concept. I really hope that one positive outcome of this whole thing is stronger pressure on oil-drilling companies WORLDWIDE to have more effective emergencie and safety procedured developed to match the new, more dangerous conditions under which oil exploration and procurement is taking place.

And while I agree BP should pay, I also keep recalling the involvement of Halliburton in both this and the Australian blowout, which took place at a suspiciously similar point in the drilling process.

2005 was a very bad season for Mexico and the US. At least we seem to have benefited in terms of improved forecasting for the entire basin. Let's hope the world gets more from DWH disaster than an opportunity to bash oil executives, US politians, and TV personalities....
Member Since: October 25, 2005 Posts: 19 Comments: 22687
Quoting CybrTeddy:


Nah, but he's been trackin em well longer than StormTop claims he has.
ROFL! Ya' know I'm just messin' with him.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting earthlydragonfly:
Why cant I read what Gator says??? Did I get blocked by him??? LMAO I have never been on someone's ignore list before.


I consider it a badge of honor!
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1132. FLdewey 1:53 AM GMT on July 13, 2010 Hide this comment.

Quoting Tazmanian:
you guys skip right ovee commet 1096



We were trying not to notice you can't even spell NOSE. ;)



POOF



would any one like too joine him???



i will not have none of that
Member Since: May 21, 2006 Posts: 5091 Comments: 115439
Quoting MiamiHurricanes09:
LMAO! I wonder if he remembers the birth of Albert Einstein.


Nah, but he's been trackin em well longer than StormTop claims he has.
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Quoting CybrTeddy:


Grothar's the best when it comes to tracking cyclones, he's been tracking them for years.. all the way back to the Lincoln administration. Ha kidding.


Not a stretch...his baby pictures were taken by Mathew Brady.
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re post


1096. Tazmanian 1:43 AM GMT on July 13, 2010

Quoting AustinTXWeather:
Hi all! Nice to see D.r Masters is back. Can anyone tell me what makes a system "sub-tropical"?




sure thing when it has 2 eyes a nos and it can talk
Member Since: May 21, 2006 Posts: 5091 Comments: 115439
Quoting CybrTeddy:


Grothar's the best when it comes to tracking cyclones, he's been tracking them for years.. all the way back to the Lincoln administration. Ha kidding.
LMAO! I wonder if he remembers the birth of Albert Einstein.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting CybrTeddy:
Intensity doesn't matter when it comes to retiring storms. In some cases, nor does damages and death totals. Hurricane Gordon in 1994 killed 1,000+ people, wasn't retired.


WHO normally does not retire storms that primarily affect Haiti. Due to the fact that most of the damage that is done to Haiti could be prevented. As an example deforestation has probably contributed to storms that have killed many people in Haiti from landslides as well as fast moving flood waters such as Gordon from 1994 and Hanna in 2008.
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Why cant I read what Gator says??? Did I get blocked by him??? LMAO I have never been on someone's ignore list before.
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gonna still go with my early numbers....16 8 4...lookin for active aug n september anyone agree with me on these numbers n that the next 2 months will probably be active???
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Quoting earthlydragonfly:
did I get popped too?


Not on my end.
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Quoting MiamiHurricanes09:
Uh-oh! It's Grothar! LOL.


Grothar's the best when it comes to tracking cyclones, he's been tracking them for years.. all the way back to the Lincoln administration. Ha kidding.
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Hey StormW good night.
but your gonna miss the COC argument that is about to ensue!
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Quoting StormW:


SubTropical cyclone


Thanks StormW :) -so main distinctive factors are max winds farther from eye and no fronts associated. Good to know!
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Quoting Grothar:


Don't you be stealing any of my globes while I am off. I have been watching all day.
I've got it covered! You might want to minus post #1117 though, LOL.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
did I get popped too?
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you guys skip right ovee commet 1096
Member Since: May 21, 2006 Posts: 5091 Comments: 115439
Quoting all4hurricanes:
No politics I don't care who's bashing or who's fault it is I started a nice discussion about Alex join that if you like
We'll see Alex's total damages at the end of the season I'm thinking they might top 2 billion but I also believe there is a good chance Mexico won't suggest retirement.

The Mexican Government has MANY serious problems. They even charge their own citizens for relief supplies, very, very, very disturbing.

I reviewed the pictures out of Monterrey, Mexico. The damage was catastrophic, the damage to roads, bridges, infrastructure throughout the entire Monterrey Greater Metro Area.

Remote villages were cut off, only the Master of all dimensions knows how many smaller mountain villages were wiped off the face of the Earth, how many lives were lost and how many people who weren't accounted for.

They received 18-36" of rain in 48 hours. The annual rainfall in that area is 18" a year
. A fellow WU blogger reported on our blog the shear shock and amazement of how much damage was done in Monterrey proper. People in that city of 1.5 million people were BEGGING for help. Sadly, their cries went unanswered for many days, until the Mexican Government rushed in aid.

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1119. Grothar
Quoting MiamiHurricanes09:
Uh-oh! It's Grothar! LOL.


Don't you be stealing any of my globes while I am off. I have been watching all day.
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Quoting sailingallover:
You know there is always lots of cool stuff in the sat pics and loops. And everyone can use practice looking and analyzing...


You said it!
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Hehehehehehehehehe...

Member Since: September 2, 2009 Posts: 130 Comments: 21194
1116. Grothar
Quoting GeoffreyWPB:
Hi Grothar...What are you doing up past your bedtime?


Going to bed, just had to look up the name Arlene before I did. LOL
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You know there is always lots of cool stuff in the sat pics and loops. And everyone can use practice looking and analyzing...
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Quoting KoritheMan:


Arlene.


Yeppers...the first named storm for next year.
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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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