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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1014. Dakster
Quoting TropicalAnalystwx13:


Its a smile :D


Ask KOTG - He seems to have all the smileys around here... But it does look like a sadistic wal-mart smiley.
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1013. bappit
I'm hearing that the Coast Guard passes the buck.

Edit: I don't think that is true. The Coast Guard has a reputation for integrity.
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from the very beginning i've said hang em high.
oh well. just hope the plug works, we take bp for everything they have, and this never happens again.
rant when it starts, rant when it's over.
let's hope it's over. good grief.
a lot depends on this plug holding.
sorry to diss the coast guard.
know they were just following orders.
glad they finally helped to force the hand that will stop this infernal abomination.
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Quoting earthlydragonfly:
Is that an ominous smile I see over africa... Or is that the wal-mart?? Creepy or just a discount on the tropics this year??



Its a smile :D
Member Since: July 6, 2010 Posts: 113 Comments: 32860
Quoting StormW:


Well, my guys can only do what the Commandant allows them to do. And of course, the Commandant has a bigger boss.


exactly. which is why that guy should resign.
it would probably do a lot for morale.
my brother lives on the water has loved it all his life. spends his time now sailing around san franciso bay! good for him.
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1008. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #9
SEVERE TROPICAL STORM CONSON (T1002)
9:00 AM JST July 13 2010
============================

SUBJECT: Category Two Typhoon In Seas East Of The Philippines

At 0:00 AM UTC, Severe Tropical Storm Conson (975 hPa) located at 14.3N 124.8E has 10 minute sustained winds of 60 knots with gusts of 85 knots. The cyclone is reported as moving west at 14 knots.

Storm Force Winds
=================
60 NM from the center

Gale Force Winds
=================
150 NM from the center

Forecast and Intensity
========================
24 HRS: 15.8N 120.5E - 70 knots (CAT 3/Strong Typhoon)
48 HRS: 17.3N 117.2E - 75 knots (CAT 3/Strong Typhoon)
72 HRS: 19.3N 113.9E - 80 knots (CAT 3/Strong Typhoon)
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Quoting SavannahStorm:


Yikes, don't let the Chief read that!

my brother was a chief warrant officer in the coast guard. you follow orders. and orders were to do what bp wanted. orders in the military come from the top. nobody had nuthin to say about it. they did what they were told and am sure that really peed off a lot of enlisted people and officers.
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Is that an ominous smile I see over africa... Or is that the wal-mart?? Creepy or just a discount on the tropics this year??

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Quoting Chicklit:

Jo Y'all
yeah, saw the keith oberman thing at mom's house during dinner. why did it take them two months to put a cap on the gusher? cuz they wanted the oil, that's why, and didn't give a crap about polluting the gulf. it was the coast guard finally who grew what it took to make them do something after being their pansy boys for 6 weeks.


Yikes, don't let the Chief read that!
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Jo Y'all
yeah, saw the keith oberman thing at mom's house during dinner. why did it take them two months to put a cap on the gusher? cuz bp wanted the oil, that's why, and didn't give a crap about polluting the gulf. it was the coast guard finally who grew what it took to make them do something after being nothing more than bp's pansy boys for 6 weeks.
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Quoting MiamiHurricanes09:
Have you seen the one for Miami?

Annual Weather Summary: November 2009 to October 2010

Winter will be warmer than normal, on average, with the coldest temperatures occurring in mid-January. Rainfall will be above normal, with the best chance for any snow in the north around Christmas.

April and May will be warmer and much drier than normal.

Summer will be cooler and rainier than normal, with the hottest periods in early to mid- and mid- to late August. Watch for a major hurricane in late August or early September.

September and October will be slightly cooler and much rainier than normal.


Well, you can take that forecast and reverse it and that's what happened in SE Georgia.
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Hey ike is that cbs 4 walter cronkite reincarnated with a fishy shower curtain lol.And ike your spot on so far 1-1-1.Long way to the 20's isnt it.
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Quoting CybrTeddy:


How deep did the 2007-08 La Nina get?
No idea, but I do know it was a moderate La Nia, telling from that I'm guessing -1.5%u02DAC or so.
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Quoting MiamiHurricanes09:
I think so.



How deep did the 2007-08 La Nina get?
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no baltimore you do not have to worry about hurricanes .I do think your ravens will be a handful though.Plenty new weapons for flacco and of course you still have sugar ray and easy ed good luck to your ravens, they play the world champs this year,
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Quoting CybrTeddy:
I'm praying for La Nina to hold, because us in the south can't handle another cold winter like we had. Here in Hillsborough all our strawberries came in late, and farmers used up a lot of water in the aquifer, sinkholes formed everywhere. Farmers lost a lot of money, lots of produce too.
I think so.

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Very LARGE sticker on side of Cap

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Link

Funny how that ULL is traviling the same path as our last two gulf event's a sign of things to come maybe?
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I'm praying for La Nina to hold, because us in the south can't handle another cold winter like we had. Here in Hillsborough all our strawberries came in late, and farmers used up a lot of water in the aquifer, sinkholes formed everywhere. Farmers lost a lot of money, lots of produce too.
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Quoting TropicalAnalystwx13:


Where'd you find that??
Link
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Quoting largeeyes:


Olbermann shoulda stuck with calling home runs and touchdowns.


Why? It's a good question, and one that the other oil companies are likely paying attention to. Hopefully, their crisis teams are modifying emergency response protocols so that they can pro-actively work to contain future spills, instead of re-actively working to figure out how to do it, as BP is doing now.
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Quoting MiamiHurricanes09:
Have you seen the one for Miami?

Annual Weather Summary: November 2009 to October 2010

Winter will be warmer than normal, on average, with the coldest temperatures occurring in mid-January. Rainfall will be above normal, with the best chance for any snow in the north around Christmas.

April and May will be warmer and much drier than normal.

Summer will be cooler and rainier than normal, with the hottest periods in early to mid- and mid- to late August. Watch for a major hurricane in late August or early September.

September and October will be slightly cooler and much rainier than normal.


Where'd you find that??
Member Since: July 6, 2010 Posts: 113 Comments: 32860
AO
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video of
Installing Capping Stack to Top of the Transition Spool



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Quoting TropicalAnalystwx13:
This is for the Southeast:


September 2010
1st-3rd. Thunderstorms clear Atlantic Coast, turning pleasant.
4th-7th. Potentially stormy Labor Day weekend, with a hurricane threat.
Have you seen the one for Miami?

Annual Weather Summary: November 2009 to October 2010

Winter will be warmer than normal, on average, with the coldest temperatures occurring in mid-January. Rainfall will be above normal, with the best chance for any snow in the north around Christmas.

April and May will be warmer and much drier than normal.

Summer will be cooler and rainier than normal, with the hottest periods in early to mid- and mid- to late August. Watch for a major hurricane in late August or early September.

September and October will be slightly cooler and much rainier than normal.
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Quoting StormW:


When you see the AO plunge, that's when all the cold Arctic air heads south.
Oh, LOL! In my question I said negative rather than positive.
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Quoting fatlady99:
well, I guess the non response to my inquiry about weather radios means that it's too dumb a question to consider. For that matter, even the NOAA won't recommend anything.

I do think there may be others lurking, tho, who could benefit from your collective experience.



I'm pretty sure Lowe's, Home Depot, even Wal-Mart and K-Mart and most of your drug stores supply E-Radios that do a good job.
Lowes has been selling some around here they seem to do a good job when the weather gets bad I think it's one you hand crank don't know how long the charge last's though I have a battery operated one w/ tv that works find just need to stock up on the battery's.
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I wish I had experience with hand crank weather radios. I do need to get one... What is your budget. I have seen them provide 12v car plugs to charge your cell phone. Some are very basic and other feature rich. Some are small and others not so much.

Do you want battery and hand crank power or not?
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Quoting StormW:


Watcha need to know on weather radios?


Thank you Storm. You're always a gentleman. :)

I'm just looking for a recommendation. Some of them are very expensive and beyond my ability. some of them are red cross battery hand crank monsters that will charge your cel phone and light your tent. Any thoughts on a good and reasonably priced one?
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Northeast:

August 2010
1st-3rd. Fair
4th-7th. Thunderstorms New England into Mid-Atlantic States, then mainly fair.
8th-11th. Heavy showers, with isolated severe storms possible, then clearing.
12th-15th. Pleasant weather.
16th-19th. Thunderstorms, turning fair.
20th-23rd. Fair, then unsettled, with showers.
24th-27th. Mostly fair, hot.
28th-31st. Hurricane threat.
Member Since: July 6, 2010 Posts: 113 Comments: 32860
This is for the Southeast:


September 2010
1st-3rd. Thunderstorms clear Atlantic Coast, turning pleasant.
4th-7th. Potentially stormy Labor Day weekend, with a hurricane threat.
Member Since: July 6, 2010 Posts: 113 Comments: 32860
Quoting StormW:


Aye! And the plunge of the AO.
Doesn't a negative AO cause lower Arctic pressures and warmer temperatures across the U.S.? Just making sure if that is right.
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2010 Almanac:

August 2010

1st-3rd. Gusty winds, showery New Mexico, Texas, parts of Oklahoma.

4th-7th. Mostly fair, hot.

8th-11th. Rain Texas. Gusty winds Southern Plains.
12th-15th. Fair, turning unsettled.

16th-19th. Pleasant.

20th-23rd. Fair, then showers Southern Rockies east.

24th-27th. Fair weather gives way to unsettled conditions over Southern Rockies. Hurricane threat along Gulf Coast.
28th-31st. Thunderstorms move through Texas east.

Member Since: July 6, 2010 Posts: 113 Comments: 32860
well, I guess the non response to my inquiry about weather radios means that it's too dumb a question to consider. For that matter, even the NOAA won't recommend anything.

I do think there may be others lurking, tho, who could benefit from your collective experience.

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Quoting KoritheMan:


That, and a negative phase of the NAO (I think).
Yup. Normally the NAO phases have a more direct affect in Europe, but they also affect the climate in eastern North America. This is how it works, when the NAO is in a positive phase the Icelandic low draws to the stronger south-westerly circulation over the eastern half of the North American continent which prevents Arctic air from plunging southward. If you match this up with a La Nia you are bound to have a significantly warmer winter.
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Quoting IKE:
Keith Olbermann just asked a real good question...why didn't BP have this back on April 20th when this happened?


Olbermann shoulda stuck with calling home runs and touchdowns.
Member Since: August 22, 2006 Posts: 0 Comments: 1462

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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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