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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Quoting Patrap:
Conson






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For all his wonderful work he has done in Tampa, i would hppe he would be honored with Flags at half mast. Geroge was really that kind of caring person of his community and people. I have meet him and his family and his Children will have a hard legecy to live up too!
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1561. hcubed
Quoting hurrkat05:
lol man you guys must be really bored tonight...get used to it it will be like this for the rest of the month and even into early august...


So bored, I'm even reading YOUR posts...
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1560. Drakoen
It appears the models strongly agree on the strength of the MJO in our basin. I know the GFS and GEFS were posted before. Here is the UKME (UKMET ensembles) and BOME (Australian Bureau of Meteorology - Global Analysis and Prediction Ensemble System)



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Bastardi's blog

In the end, there is only one debate left about the entire warm season this year, and that is the hurricane season, which has shut down since the first revving-up. Cloud shots indicate a large-scale wave in the east-central Atlantic, and this will be something to watch as it will be in the Bahamas this weekend, but right now dry air is killing its convection. There was an SOI downturn in June, but it's cranking again now as the La Nina base state is really starting to go. A cooling Pacific, still warm Atlantic and positive height anomoly over the Great Lakes in the means for the hurricane season, along with a very warm AMO (latest is .495, second only to 1998 for June.. a year similar to this that really revved up in the heart of the season) all means that its no time for the faint of heart for the Atlantic season. We do have a Pacific typhoon and the western North Pacific has increased to 8% of normal, while the Atlantic and southeast Pacific together are actually above normal so far with the ace index. Overall global activity remains below normal, a little over 85%.

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Tampa Station 620am about Steinbrenner
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Quoting StormW:
TROPICAL WEATHER SYNOPSIS JULY 13, 2010 ISSUED 10:00 A.M.

Good morning StormW. I am on my way over to your blog as we speak :o)!
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Quoting CaribbeanIslandStorm:

he just passed away :(

How sad, he has contributed much to the Yankee organization. My condolences to his family..
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1552. IKE
Quoting CaribbeanIslandStorm:

he just passed away :(


Oh no, sorry to read that....tonight's the All Star Game.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Patrap:
George Steinbrenner HEART ATTACK: Yankees Owner In Extremely Critical Condition

BREAKING: New York Yankees owner George Steinbrenner has been rushed to the hospital after suffering a massive heart attack.

The 80-year-old Steinbrenner has been in ill health for years, and is believed to be in extremely critical care.

Steinbrenner has owned the Yankees since 1973.

he just passed away :(
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1550. IKE


Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Patrap:
George Steinbrenner HEART ATTACK: Yankees Owner In Extremely Critical Condition

BREAKING: New York Yankees owner George Steinbrenner has been rushed to the hospital after suffering a massive heart attack.

The 80-year-old Steinbrenner has been in ill health for years, and is believed to be in extremely critical care.

Steinbrenner has owned the Yankees since 1973.


Mr. Steinbrenner whom lives in Tampa...has been a tremendous asset and great and generous person for the Tampa Bay Community. Not a Yankee fan by no means but, certainly a Steinbrenner Fan.
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1548. Patrap
DATE: July 12, 2010 17:45:08 CST
Statement from National Incident Commander Admiral Thad Allen on Well Integrity Test

Deepwater Horizon Incident
Joint Information Center

Phone: (713) 323-1670
(713) 323-1671



"Significant progress has been made on the capping stack installation. As a result of that progress, BP will perform a "Well Integrity Test" tomorrow morning. This test involves closing one or more of the valves on the new cap for a period of time to allow BP to measure pressures in the well.

It also requires that the Helix Producer and Q4000 collection systems be ramped down and placed in standby mode during the test. The measurements that will be taken during this test will provide valuable information about the condition of the well below the sea level and help determine whether or not it is possible to shut the well for a period of time, such as during a hurricane or bad weather, between now and when the relief wells are complete.

I have reviewed the protocols for this test, in consultation with the government science team. The test will likely last anywhere from 6-48 hours or more depending on the measurements that are observed. BP will be in regular contact with the government during the test, and the government will halt the test if the risks of doing further damage to the surrounding formation are significant.

Once the test has concluded, collection of the oil will resume."
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1547. ackee
Seems like shear and dust will put a damp on the hyper active seasons most agent was forecasting oh where is La nina ? some forecast La nina forming by july and reduceing vertical wind shear that has not happen either with that see no more than 15 name storms
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1546. Patrap
Quoting earthlydragonfly:


I thought it was capped last night... I saw them put that rig on the leak.. what happened?


Pressure test's showed a few flaws.

Imagine dat?
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1545. angiest
Quoting earthlydragonfly:


I thought it was capped last night... I saw them put that rig on the leak.. what happened?


The new cap has been put in place but not sealed yet. It will take some number of hours to verify it will hold under the internal and external pressures.
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1544. IKE
Quoting ackee:
how will storm track if Ecmwf is right about the A/B high


Not sure...depends on how strong the high is when systems form and where they form and if there's troughs to steer them into fish-land.


I found this from Dr. Masters June 1st, 2010 blog on the SAL outlook for this season....

"Dust expert Professor Amato Evan of the University of Virginia has posted his forecast for African dust for the 2010 hurricane season. Dr. Evan is predicting that due to plentiful rains during last year's rainy season over the Sahel region of Africa, and near average amounts of African dust observed in May 2010 and during the 2009 hurricane season, we can expect near average or moderately below average levels of dust over the tropical Atlantic during the 2010 hurricane season."
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1543. kelley9
Quoting MiamiHurricanes09:
That's your mistake. When using Internet Explorer you do not have spell check, the blog may appear stretched, and several tabs may be missing. I recommend you download the latest version of Firefox.

Sorry, had to do it...LOL.



Best graphic ever.
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AOI

AOI

AOI

AOI

TS BUSTED FORECAST ALIBI
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1540. MTWX
morning all!! I love the fact everyone keeps downcasting the season. Once the train gets moving it won't stop till the end of the season IMO.
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1539. ackee
Quoting IKE:


True.
Quoting MiamiHurricanes09:
ECMWF 00z 240 hours. Note the A/B high.

how will storm track if Ecmwf is right about the A/B high
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Quoting Patrap:
Morn' CT

BP Live feeds from remotely operated vehicles (ROV)

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Live video links from the ROVs monitoring the damaged riser.
Please be aware, these are live streams and may freeze or be unavailable from time to time.
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I thought it was capped last night... I saw them put that rig on the leak.. what happened?
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1537. Patrap
George Steinbrenner HEART ATTACK: Yankees Owner In Extremely Critical Condition

BREAKING: New York Yankees owner George Steinbrenner has been rushed to the hospital after suffering a massive heart attack.

The 80-year-old Steinbrenner has been in ill health for years, and is believed to be in extremely critical care.

Steinbrenner has owned the Yankees since 1973.
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1536. Patrap
Morn' CT

BP Live feeds from remotely operated vehicles (ROV)

ROV footage - live stream
Live video links from the ROVs monitoring the damaged riser.
Please be aware, these are live streams and may freeze or be unavailable from time to time.
Live feeds from Ocean Intervention III

ROV 1
ROV 2
Live feeds from Viking Poseidon
ROV 1
ROV 2
Live feeds from Boa Deep C
ROV 1
ROV 2
Live feeds from Skandi
ROV 1
ROV 2
Live feeds from Enterprise
ROV 1
ROV 2
Live feeds from Q4000
ROV 1
ROV 2
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Morning Pat
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1534. Patrap
All NOAA Floater Imagery
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1533. cg2916
Quoting Patrap:
Conson



Wow.
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1532. Patrap
.Itsa gift from above dey say..

G'morning WUnderland
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1531. cg2916
Quoting Patrap:
.."Caught in a Bad invest"..


Your puns never get old.
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1530. Patrap
Conson

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1529. cg2916
Quoting hurrkat05:
the dust will take over ay least until ealy august then conditiond shoud start to come down..this year seems to be average at best..nothing like the 2005 season we had..our only hope to get something to form is going to be on and old front stalled in the gom and i don't see that happening anytime soon..


No, dust should be gone by next week.
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1528. Patrap
.."Caught in a Bad invest"..
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1526. cg2916
Whoa, blog just stopped.
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Quoting BahaHurican:
Not really... this is the type of dust one might more typically have been seeing all through June as well, but that hasn't been the case. Instead, dust has been notably absent until this week...


Predicted storms are only an estimate based on history and scientific analysis of the conditions that would create tropical activity. Mother Nature always has the last say. Luckily nobody will get hanged for their scoreless predictions.
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1524. KEEPEROFTHEGATE (Mod)
off to work i go check back at lunch
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1523. KEEPEROFTHEGATE (Mod)
Quoting IKE:



Hmmm....nah.
you saw that huh
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Quoting MahFL:
Didn't Dr Masters say the African dust would be less this year due to plentifull African rain, seems like that part of his forcast is BUSTED.....as for Bastardi's 4 named storms in July.....
Not really... this is the type of dust one might more typically have been seeing all through June as well, but that hasn't been the case. Instead, dust has been notably absent until this week...
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Mail Storm W
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Ah... this is what I want.... and it gives a perfect explanation for what I noticed on the EUMETSAT dust map....





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1517. IKE
Member Since: June 9, 2005 Posts: 23 Comments: 37858
I found this, though this is the entire continent rather than just the north part....

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Good Morning I see our friend sal is dying and we have a good looking wave at 55w witch could mean more rain for me down the road as only land interaction will keep it from developing
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Quoting StormW:
Baha,
Here's a start:

Medium Range Forecasts for Africa
TYVM, TYVM.... this is quite useful indeed....
Member Since: October 25, 2005 Posts: 19 Comments: 21453

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About

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