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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2714. JLPR2
Quoting centex:
LOL, your out of touch. Don't you follow the news? I thing you live elsewhere and don't care.


What are you talking about?
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2713. JLPR2
Quoting xcool:
JLPR2 .wow


Not sure if that's a wow but so far its sustaining itself.
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2712. centex
Quoting JLPR2:


Nope, No S. Tx XD
LOL, your out of touch. Don't you follow the news? I think you live elsewhere and don't care.
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2711. xcool
JLPR2 .wow
Member Since: September 26, 2009 Posts: 2 Comments: 15671
2710. JLPR2


Not much to watch here =)
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2709. xcool


Member Since: September 26, 2009 Posts: 2 Comments: 15671
Quoting JLPR2:


Yup, I'm a little worried of what mischief(:P) that -NAO might bring.
The dry air is shrinking and for some reason its going northwards towards Bermuda instead of entering the Caribbean, hmm... those clear skies at the Caribbean are bad news too. :\

So far this season has not produced much, well yeah a Cat 2 is not nice, but with how everything is setting up this could get nasty.

Unfortunately, things will ramp up as we move into August and September. Another several days of quiet, however everyone, do not get lulled into a false sense of security.

All this heat energy will be expended. The $64,000 question is how many TC's and where?!?!?!
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2707. JLPR2
Quoting centex:
Not much unless you don't live in S. TX.


Nope, No S. Tx XD
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Quoting JLPR2:


yep looking good



Yep, its climbing up rather quickly as of late.



Congrats Taz! XD




thanks
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Quoting CoffinWood:


Congratulations, dude!



thank you
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2704. centex
Quoting JLPR2:


Yup, I'm a little worried of what mischief(:P) that -NAO might bring.
The dry air is shrinking and for some reason its going northwards towards Bermuda instead of entering the Caribbean, hmm... those clear skies at the Caribbean are bad news too. :\

So far this season has not produced much, well yeah a Cat 2 is not nice, but with how everything is setting up this could get nasty.
Not much unless you don't live in S. TX.
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We got sum beautiful(in a bad way) supercells in ND! geez! watch out Bismarck!(looks like it will go south but id he hell awake right now if i were there..there are definitely tornadoes..
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2702. xcool



Member Since: September 26, 2009 Posts: 2 Comments: 15671
looks forword too the end of july
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2700. JLPR2
Quoting Bordonaro:


Notice the SAL layer is slowly subsiding. Notice the shaded areas are decreasing in size.

When we go back towards a -NAO, the environment will slowly moisten and and the MJO upward pulse in this area may create problems.


Yup, I'm a little worried of what mischief(:P) that -NAO might bring.
The dry air is shrinking and for some reason its going northwards towards Bermuda instead of entering the Caribbean, hmm... those clear skies at the Caribbean are bad news too. :\

So far this season has not produced much, well yeah a Cat 2 is not nice, but with how everything is setting up this could get nasty.
Member Since: Posts: Comments:
2699. JRRP
NGP
Link
Link
See you tomorrow
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Quoting JLPR2:
Dry Air:

Notice the SAL layer is slowly subsiding. Notice the shaded areas are decreasing in size.

When we go back towards a -NAO, the environment will slowly moisten and and the MJO upward pulse in this area may create problems.
Member Since: Posts: Comments:
2697. centex
My point which is much understood. Only JM and stormw does not make me mad.

I watch NHC not the bloggers on this site. First read the orignal blog than NHC if you start from that you wil know what is going on. This blog is good for breaking news on storm, but not good for prediction on current storm. They tend to follow unreliable models and don't use experience like NHC does.
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2695. xcool
dry air
Member Since: September 26, 2009 Posts: 2 Comments: 15671
2694. centex
Quoting LawStudent:
Centex, you still around?
Yes but not much longer.
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2692. JLPR2
Dry Air:
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Quoting Tazmanian:
hey guys i made it too 50,000 commets


Congratulations, dude!
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2690. JLPR2
Quoting KoritheMan:
Pre-Estelle starting to organize:



yep looking good

Quoting CyclonicVoyage:


Understand. Looking now at the ITCZ, the time is near.


Yep, its climbing up rather quickly as of late.

Quoting Tazmanian:
I DID IT I DID IT



YAY YAY YAY


I DID IT I DID IT


YAY YAY YAY


4211 comments and 33 entries posted by all members in the last 24 hours.

You have posted 5076 entries in your own blog.

You have posted 50000 comments in all blogs.


Congrats Taz! XD
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2689. centex
Quoting KoritheMan:
Pre-Estelle starting to organize:

Yes TD now or TS. Seen millions of times.
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2687.

You didn't explicitly, but you certainly implied as much. Anyway, I'll mail you. Let's keep this blog clean!
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2687. Seastep
Quoting KoritheMan:


My, how I love religious debates. :P

Still, I'd rather keep them off the blog, not because I'm afraid to engage in them, but simply because I want to abide by the rules.

Would you like to debate with me through WU mail, Seastep? I'd be most interested. Not so I can "win", but so I can understand your position.


Absolutely! Wumail me. Very busy lately, but I'll get to it.

Did I mention religion at all there? Only math and science.

Again, Darwinism and adaptation/evolution are two separate things.
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Pre-Estelle starting to organize:

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2685. Motttt
yep still flowing strong
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2684. centex
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2683. xcool
huh 1947
Member Since: September 26, 2009 Posts: 2 Comments: 15671
Just looked at the live cams on the oil spill.......its not pretty but, i sure hope this works.
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Man. Amazing. Its just like 1947 all over again.
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2680. centex
40W
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Quoting Seastep:


Probability and Statistics anyone?

Protein is life. 20 amino acids in proteins are the base of all life. Proteins can contain as many as 300 combinations in any given life form.

The probability of duplicating two identical proteins, just using a 100 sequence, is 20^100. That's a one followed by 130 zeros (10^130).

As perspective, the number of seconds since the big bang is less than 10^18. That's one followed by 18 zeros.

To reach a probable conclusion that a protein (life) developed by chance, we would need 10^110 attempts PER SECOND since the beginning of time.

Now for some physics.

To perform those attempts would require 10^90 grams of carbon. The entire mass of the Earth (all elements) is 6*10^27 grams. This is much smaller than than the 10^90. 10^90 is actually billions of times more than the mass of the entire universe.

CERN.

Have been too busy to check on CERN, but now that I've been sparked and slow period, of course the Atlantic will heat up and I won't get to it! :)

As a side note, it is actually the case that the more we learn and discover through science, the less and less likely it becomes. Take elements, as an example. More now than when I was educated. More complexity = less probability of chance. e.g., put more than 20 amino acids into that equation and what do you get?

The bottom line is that the more we learn... the less likely Darwinism becomes. Just math. And, don't confuse adaptation with evolution. Two separate things entirely.

OK. Now I've taken way too long, and am way late in reply... but that's my MO, LOL.

Goodnight all.

Apologies for the off-topic, but it is slow atm.

Is Taz around? **looking over shoulder** ;)


My, how I love religious debates. :P

Still, I'd rather keep them off the blog, not because I'm afraid to engage in them, but simply because I want to abide by the rules.

Would you like to debate with me through WU mail, Seastep? I'd be most interested. Not so I can "win", but so I can understand your position.
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2678. centex
40+ wave
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Rest up folks, not long before we're tracking 2 or 3 at a time.

Night All.
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Quoting JLPR2:


Yes of course, we already had Alex and Td2, I guess the starting late idea is just a figure of speech, as in, when we start tracking and dont stop. XD



Understand. Looking now at the ITCZ, the time is near.
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2672. xcool
lol
Member Since: September 26, 2009 Posts: 2 Comments: 15671
Quoting btwntx08:

how did that happen



ask him lol
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now back too the weather
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hey guys i made it too 50,000 commets
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2667. HadesGodWyvern (Mod)
Philippines Atmospheric Geophysical Astronomical Service and Administration
TROPICAL STORM "BASYANG" (CONSON)
Tropical Cyclone Bulletin #10
==============================================

Tropical Storm "BASYANG" has maintained its strength as it moves away from the country.

At 10:00 AM PhST, Tropical Storm Basyang (Conson) located at 14.6°N 118.6°E or 150 km southwest of Iba, Zambales has 10 minute sustained winds of 50 knots with gusts of 65 knots. The cyclone is reported as moving west at 11 knots.

Signal Warnings #1
=======================

Luzon Region
------------
1.Batangas
2.Cavite
3.Lubang Island
4.Bataan
5.Zambales
6.Northern Mindoro
7.Metro Manila

Additional Information
========================
Public Storm Warning Signals elsewhere are now lowered.

Residents in low-lying areas and near coastal areas, and near mountain slopes under signal #1 are advised to take all the necessary precautionary measures against flash floods and landslides.

The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 5 PM today.
Member Since: May 24, 2006 Posts: 50 Comments: 45302
2666. JLPR2
Quoting centex:
watching 40W also. Stormw liked that area best. It seems to be our best AOI next 48 hours. Not great chance but all we have at this time.


lets start posting pictures then XD LOL!

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2665. centex
Quoting xcool:
quiet won't last much longer
watching 40W also. Stormw liked that area best. It seems to be our best AOI next 48 hours. Not great chance but all we have at this time.
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2664. Motttt
not any thing that I have read
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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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