CSU and TSR predict above average 2012 Atlantic hurricane season

By: Dr. Jeff Masters , 5:17 PM GMT on December 07, 2011

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Above-average Atlantic hurricane activity is likely for 2012, but there is a 40% chance of an El Niño event that will keep hurricane activity below average, according to the latest seasonal forecast issued today by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). For the first time in twenty years, the CSU team is not issuing a December forecast with a specific number of tropical storms and hurricanes. Instead, they have issued a more qualitative forecast, which I think is a great idea, since their quantitative December forecasts have shown no skill. Their outlook for the 2012 Atlantic hurricane season:

15% chance: Very active season with 14-17 named storms, 9-11 hurricanes, 4-5 major hurricanes
45% chance: Active season with 12-15 named storms, 7-9 hurricanes, 3-4 major hurricanes
30% chance: Inactive season with 8-11 named storms, 3-5 hurricanes, 1-2 major hurricanes
10% chance: Very inactive season with 5-7 named storms, 2-3 hurricanes, 0-1 major hurricanes

An average season has 11 named storms, 6 hurricanes, and 2 intense hurricanes. The main reason that CSU's December forecasts have shown no skill is because we have no skill predicting El Niño events nine months or more into the future. When an El Niño event occurs, bringing much above average wind shear over the tropical Atlantic, hurricane activity is substantially reduced. Making successful seasonal hurricane forecasts requires that one make a successful El Niño forecast.


Figure 1. Forecasts of El Niño conditions by 20 computer models, made in November 2011. The longest range forecasts for July-August-September (JAS) at the right side of the image show that 3 models predict weak El Niño conditions, 8 predict neutral conditions, and 1 predicts a weak La Niña. El Niño conditions are defined as occurring when sea surface temperatures in the Equatorial Pacific off the coast of South America (the "Niño 3.4 region) rise to 0.5°C above average (top red line). La Niña conditions occur when SSTs in this region fall to 0.5°C below average (blue line.) Image credit: Columbia University.

What will El Niño do in 2012?
We currently have a borderline weak to moderate La Niña episode in the Eastern Pacific, characterized by cooler than average waters off the equatorial coast of South America. While we can say with good confidence that La Niña will continue through the winter and into spring, it is highly uncertain what might happen next summer and fall to La Niña. In April and May, we typically see La Niña fade to neutral, and in many cases, a full-blown El Niño will develop by the fall. As the CSU team notes, there have been fourteen years since 1950 which had La Niña conditions that were similar to what we are experiencing this December. During the following years' hurricane season, an El Niño event developed 36% of the time, in those fourteen years. In 2012, the odds of a fall El Niño may be higher than this, since we have gone three years since the last El Niño, and these events typically occur every 3 - 7 years. Of the 12 El Niño/La Niña computer models that made November predictions for the July-August-September 2012 portion of hurricane season (Figure 1), only 3 (20%) predicted that El Niño would arrive. However, these models have no skill predicting El Niño so far in advance.

2012 Atlantic hurricane season forecast from Tropical Storm Risk, Inc.
The British private forecasting firm Tropical Storm Risk, Inc. (TSR), issued their 2012 Atlantic hurricane season forecast today. TSR is calling for an above-average year, with 14.1 named storms, 6.7 hurricanes, and 3.3 intense hurricanes. TSR predicts a 49% chance of an above-average hurricane season, 30% chance of a near-normal season, and a 21% chance of a below normal season. TSR bases their December forecast on predictions that sea surface temperatures next fall in the tropical Atlantic will be above about 0.1°C above average, and trade wind speeds will be about 0.2 m/s slower than average. The trade wind speed prediction is based on a forecast for neutral El Niño conditions in August - September 2012.

I like how TSR puts their skill level right next to the forecast numbers: 3% skill above chance at forecasting the number of named storms, 0% skill for hurricanes, and 7% skill for intense hurricanes. That's not much skill, and really, we have to wait until the June 1 forecasts by CSU, NOAA, and TSR to get a forecast with reasonable skill.


Figure 2. Forecast skill of the TSR, NOAA (National Oceanic and Atmospheric Administration) and CSU (Colorado State University) seasonal hurricane outlooks 2002-2011 as a function of lead time. NOAA does not release seasonal outlooks before late May. It is clear there is little skill in forecasting the upcoming number of Atlantic hurricanes from the prior December. Skill climbs slowly as the hurricane season approaches. Moderate skill levels are reached by early June and good skill levels are achieved from early August. Image credit: Tropical Storm Risk, Inc (TSR).

Jeff Masters

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Quoting CybrTeddy:


I doubt that we will see under 13 named next year tbh, while December forecasts are usually off, they're usually accurate enough to tell us if a season will be active or inactive.

CSU in Dec. 2010 predicted for 2011:
17-9-5.
Actual Activity:
19-7-3.

CSU in Dec. 2009 predicted for 2010:
16-9-5
Actual Activity:
19-12-5.

CSU in Dec. 2008 predicted for 2009:
14-7-3
Actual Activity:
9-3-2.

2009 and 2006, the only two inactive seasons since 1997, where both predicted to be above average, but did not due to a El Nino. 2004 and 2002 had a El Nino Modoki, something that is new to the weather world. We are in a period though that it is more likely than not, warm-neutral conditions in 2012 seems the most likely to me.
if its warm neutral numbers should be around 13-16
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Quoting StormTracker2K:


Low of 44 here in Orlando as well but back to mid to upper 50's Thursday night.
I wish the weather would make up its mind, either stay cold which I prefer, or stay hot. This hot and cold stuff just makes people sick.
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I had a 44 mph wind gust as this front came thru about 15 minutes ago.
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Quoting GTcooliebai:
Tonight's forecast for the Tampa Bay Area:



Low of 44 here in Orlando as well but back to mid to upper 50's Thursday night.
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Tonight's forecast for the Tampa Bay Area:

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Quoting StormTracker2K:
Finally a little cool down coming for only about 24 hours though.

Yes this front is coming through with a blast, I was just outside putting up some Christmas lights & it is windy as heck, my ears are actually cold!
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Quoting SPLbeater:
TC Alenga 203000Z

CI# /Pressure/ Vmax
4.6 / 971.4mb/ 79.6kt

Raw T# 5.8
Adj T# 4.6
Final T# 4.6

Scene Type: EYE


Looks about right.



Very pretty, but tiny storm, I cannot wait until visible comes in a few hours.
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TC Alenga 203000Z

CI# /Pressure/ Vmax
4.6 / 971.4mb/ 79.6kt

Raw T# 5.8
Adj T# 4.6
Final T# 4.6

Scene Type: EYE
Member Since: August 4, 2011 Posts: 46 Comments: 4486
Quoting StormTracker2K:


This blog will go crazy next summer if it's a slow hurricane season!


I doubt that we will see under 13 named next year tbh, while December forecasts are usually off, they're usually accurate enough to tell us if a season will be active or inactive.

CSU in Dec. 2010 predicted for 2011:
17-9-5.
Actual Activity:
19-7-3.

CSU in Dec. 2009 predicted for 2010:
16-9-5
Actual Activity:
19-12-5.

CSU in Dec. 2008 predicted for 2009:
14-7-3
Actual Activity:
9-3-2.

2009 and 2006, the only two inactive seasons since 1997, where both predicted to be above average, but did not due to a El Nino. 2004 and 2002 had a El Nino Modoki, something that is new to the weather world. We are in a period though that it is more likely than not, warm-neutral conditions in 2012 seems the most likely to me.
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Finally a little cool down coming for only about 24 hours though.

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The rain for TX went POOF while FL appears to be the one that gets the overrunning rains.

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Looks like some good rains are on tap this weekend for FL as this front moves back west.

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Deep convection has fully wrapped around Alenga's eye. She isn't a 65mph (10min) 70mph (1min) tropical storm.
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Quoting HuracanTaino:
Is very easy to call GW, "crap" for some people, mostly for an ideology or political reasons. But the fact is that man kind is causing changes in the climate of the panet. Now, how much or How fast these changes are occuring is a serious mankind issue,since our very existence is at hands, and obviously, more studies needs to be done. All the nations, are responsible for the future of the planet, specially the industrialize nations, China, Europe and of course,the United States are included. After all we are all in the same boat.


the reason so much is goin on is because man has tried to do things by himself. put God in control, you wont have problems.

And we are not even close to controling the future of this planet
Member Since: August 4, 2011 Posts: 46 Comments: 4486
Is very easy to call GW, "crap" for some people, mostly for an ideology or political reasons. But the fact is that man kind is causing changes in the climate of the panet. Now, how much or How fast these changes are occuring is a serious mankind issue,since our very existence is at hands, and obviously, more studies needs to be done. All the nations, are responsible for the future of the planet, specially the industrialize nations, China, Europe and of course,the United States are included. After all we are all in the same boat.
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the south pacific also has that intensity format.
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I'm going with 15 named storms, 7 hurricanes, and 4 major hurricanes myself.

I'll have a big blog entry out over it this afternoon or tomorrow.

Thanks Dr. Masters.
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Quoting HadesGodWyvern:
Tropical Cyclone Warning Center Perth
Tropical Cyclone Advisory #11
TROPICAL CYCLONE ALENGA (01U)
3:00 AM WST December 8 2011
==============================================

At 2:00 AM WST, Tropical Cyclone Alenga, Category Two (986 hPa) located at 15.0S 92.3E has 10 minute sustained winds of 55 with gusts of 75 knots. The cyclone is reported as moving east southeast at 12 knots.

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

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

Dvorak Intensity: T3.0/3.5/S0.0/24 HRS

Forecast and Intensity
======================
12 HRS: 16.1S 94.5E - 55 knots (CAT 2)
24 HRS: 17.5S 97.1E - 45 knots (CAT 1)
48 HRS: 19.3S 100.2E - 30 knots (Tropical Low)
72 HRS: 20.4S 100.6E - 30 knots (Tropical Low)

Additional Information
======================

Tropical Cyclone Alenga was located by microwave and infra-red satellite imagery over the past 6 hours. DT difficult to assign, MET was 3.0 based on S trend. FT was 3.0 but CI held at 3.5. Intensity set to 50 knots [10 minute average].

Recent microwave imagery showed a decrease in deep convection around the low level circulation center.

The system has been in a low shear environment and CIMSS shear at 18:00 UTC was about 6 knots from the westnorthwest. Shear is forecast to increase in the next 24 to 48 hours as an upper low and trough approach from the west.

Numerical Weather Prediction guidance is quite consistent with general southeast motion likely over the next 48 hours due to the upper trough. In the longer term the weakening system is likely to be steered towards the west southwest by a ridge and gales may persist to the south of the system in the tight easterly pressure gradient.

Alenga may intensify a little over the next 6 hours. There is still a chance that it may reach category 3 intensity but the approach of dry air from the southwest and increasing shear are likely to limit its intensity.


funny how the Indian oceans' category 3 in only a Atlantic 1, lol
Member Since: August 4, 2011 Posts: 46 Comments: 4486
Quoting DavidHOUTX:


that is exactly what we need! when is the next cold front coming through SE TX? All these forecast about how this winter will be well above avg temp wise and it sure as heck has been the opposite so far.


Friday, winter doesn't start till the 21st, so it still might be dry and warm after December, hope not
Member Since: July 14, 2008 Posts: 1 Comments: 9630
Tropical Cyclone Warning Center Perth
Tropical Cyclone Advisory #11
TROPICAL CYCLONE ALENGA (01U)
3:00 AM WST December 8 2011
==============================================

At 2:00 AM WST, Tropical Cyclone Alenga, Category Two (986 hPa) located at 15.0S 92.3E has 10 minute sustained winds of 55 with gusts of 75 knots. The cyclone is reported as moving east southeast at 12 knots.

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

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

Dvorak Intensity: T3.0/3.5/S0.0/24 HRS

Forecast and Intensity
======================
12 HRS: 16.1S 94.5E - 55 knots (CAT 2)
24 HRS: 17.5S 97.1E - 45 knots (CAT 1)
48 HRS: 19.3S 100.2E - 30 knots (Tropical Low)
72 HRS: 20.4S 100.6E - 30 knots (Tropical Low)

Additional Information
======================

Tropical Cyclone Alenga was located by microwave and infra-red satellite imagery over the past 6 hours. DT difficult to assign, MET was 3.0 based on S trend. FT was 3.0 but CI held at 3.5. Intensity set to 50 knots [10 minute average].

Recent microwave imagery showed a decrease in deep convection around the low level circulation center.

The system has been in a low shear environment and CIMSS shear at 18:00 UTC was about 6 knots from the westnorthwest. Shear is forecast to increase in the next 24 to 48 hours as an upper low and trough approach from the west.

Numerical Weather Prediction guidance is quite consistent with general southeast motion likely over the next 48 hours due to the upper trough. In the longer term the weakening system is likely to be steered towards the west southwest by a ridge and gales may persist to the south of the system in the tight easterly pressure gradient.

Alenga may intensify a little over the next 6 hours. There is still a chance that it may reach category 3 intensity but the approach of dry air from the southwest and increasing shear are likely to limit its intensity.
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Quoting RitaEvac:
If you are in SE TX, enjoy the sun today and tomm, clouds on the increase with overriding conditions. Possible widespread rain event coming


that is exactly what we need! when is the next cold front coming through SE TX? All these forecast about how this winter will be well above avg temp wise and it sure as heck has been the opposite so far.
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If you are in SE TX, enjoy the sun today and tomm, clouds on the increase with overriding conditions. Possible widespread rain event coming
Member Since: July 14, 2008 Posts: 1 Comments: 9630
where is HadesGodWyvern, should be here soon with the 2100Z warning lol...
Member Since: August 4, 2011 Posts: 46 Comments: 4486
TC 01S 183000Z

CI# /Pressure/ Vmax
4.6 / 971.5mb/ 79.6kt

Raw T# 3.4
Adj T# 4.6
Final T# 4.6

Scene Type: UNIFORM CDO CLOUD REGION w/ MW EYE
Member Since: August 4, 2011 Posts: 46 Comments: 4486
Quoting RitaEvac:


Sounds like weather....in other words....increase in weather, more action, more to watch, with all the videos taking of it that are in everybody's hands across the globe.


Exactly.

Quoting SPLbeater:


ah. interestin. well yeah mankind might be havin a small efect. that is city locations. now see, i care bout the envoirment and all, but i wontuse a battery operated car to be nice. there is a fine line dividing regular, and over the top. alot of people are goin over the top. (excluding WxGeekVA) puting animals at #1. im probably going to take a bunch of critisizing comments for this, but God has a plan, it will be carried out regardless of what man does. every move man makes he knew would happen. alot are prophesized. and alot that he said would happen over 2k years ago, have taken place as anticipated. let the Lord lead, and you wont be worried about a thing(not saying you are now, lol)

I feel as if this topic is going political, so this is the last comment i will post concerning climate change crap.


Well said. Good thing about the United States is that you have the freedom to choose what you want and have your own opinion. And I respect everyone's viewpoint and opinion equally.
Member Since: September 3, 2011 Posts: 13 Comments: 3475
Quoting WxGeekVA:


I don't believe in just global warming. I see it as "an increase in variability and extremes". More droughts, floods, heat waves, cold snaps, blizzards, hurricanes, and violent tornadoes will occur. With every action there is a reaction. Besides, the planet is still coming out of the ice age which is why temperatures are still getting warmer on average. More data is needed before it can be determined if, what, and how much of an impact mankind is having on the climate.


ah. interestin. well yeah mankind might be havin a small efect. that is city locations. now see, i care bout the envoirment and all, but i wontuse a battery operated car to be nice. there is a fine line dividing regular, and over the top. alot of people are goin over the top. (excluding WxGeekVA) puting animals at #1. im probably going to take a bunch of critisizing comments for this, but God has a plan, it will be carried out regardless of what man does. every move man makes he knew would happen. alot are prophesized. and alot that he said would happen over 2k years ago, have taken place as anticipated. let the Lord lead, and you wont be worried about a thing(not saying you are now, lol)

I feel as if this topic is going political, so this is the last comment i will post concerning climate change crap.
Member Since: August 4, 2011 Posts: 46 Comments: 4486
Quoting WxGeekVA:


I don't believe in just global warming. I see it as "an increase in variability and extremes". More droughts, floods, heat waves, cold snaps, blizzards, hurricanes, and violent tornadoes will occur. With every action there is a reaction. Besides, the planet is still coming out of the ice age which is why temperatures are still getting warmer on average. More data is needed before it can be determined if, what, and how much of an impact mankind is having on the climate.


Sounds like weather....in other words....increase in weather, more action, more to watch, with all the videos taking of it that are in everybody's hands across the globe.
Member Since: July 14, 2008 Posts: 1 Comments: 9630
Quoting SPLbeater:


and with this 'climate change' crap, which 'side' would you be on, 50 years and an increase on global AVERAGE temeratures go up 0.5 degrees. and millions of people are worried about it. pa-thetic!


I don't believe in just global warming. I see it as "an increase in variability and extremes". More droughts, floods, heat waves, cold snaps, blizzards, hurricanes, and violent tornadoes will occur. With every action there is a reaction. Besides, the planet is still coming out of the ice age which is why temperatures are still getting warmer on average. More data is needed before it can be determined if, what, and how much of an impact mankind is having on the climate.
Member Since: September 3, 2011 Posts: 13 Comments: 3475
Beaucoup gale warnings for nw Europe. Was pointed out by taistelutipu near end of previous Masters' blog.

Where can I find a good map of current surface analysis, etc. for the area?

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Another active one AGAIN!!!! for the 3rd time?
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Quoting WxGeekVA:


This isn't an attack on anyone. It's just my views on the issue.


and with this 'climate change' crap, which 'side' would you be on, 50 years and an increase on global AVERAGE temeratures go up 0.5 degrees. and millions of people are worried about it. pa-thetic!
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Quoting frankfish:

You listening there, Neapolitan???


This isn't an attack on anyone. It's just my views on the issue.
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Quoting WxGeekVA:


AGW is a socialist plot? Doesn't mean that at all. Taking the reality of climate change and manipulating it for a political agenda should be criminal, and is morally wrong. That goes for people on both sides of the debate.


i have no clue there was a debate, lol.
Member Since: August 4, 2011 Posts: 46 Comments: 4486
Even part of Salt Lake icing up and lakes in Minnesota

Member Since: July 14, 2008 Posts: 1 Comments: 9630
Ice filling in nicely over the Hudson Bay, lots of ice taking over large real estate now in lots of locations

Member Since: July 14, 2008 Posts: 1 Comments: 9630
Quoting SPLbeater:


and this means...?


AGW is a socialist plot? Doesn't mean that at all. Taking the reality of climate change and manipulating it for a political agenda should be criminal, and is morally wrong. That goes for people on both sides of the debate.
Member Since: September 3, 2011 Posts: 13 Comments: 3475
Quoting spbloom:


Paraphrasing Leon Trotsky, you may not want to care about AGW, but AGW cares about you.


and this means...?
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Quoting jrweatherman:


What drives the blog more crazy- a slow hurricane season or an active one but with the majority of the storms evading the US?


I think both of those apply. LOL!
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Quoting SPLbeater:
finally a tropical post, lol. thx Doc


Paraphrasing Leon Trotsky, you may not want to care about AGW, but AGW cares about you.
Member Since: May 12, 2010 Posts: 0 Comments: 428
Quoting StormTracker2K:


This blog will go crazy next summer if it's a slow hurricane season!


What drives the blog more crazy- a slow hurricane season or an active one but with the majority of the storms evading the US?
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Quoting StormTracker2K:


This blog will go crazy next summer if it's a slow hurricane season!


if your referring to my futuristic activity, then you are absolutely 100% correct there lol
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O.O at Alenga

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Quoting SPLbeater:
i have yet to track a nuetral year. 09 was El Nino, 10 and 11 were La Nina.


This blog will go crazy next summer if it's a slow hurricane season!
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Post #8 addition

Scene Type: UNIFORM CDO CLOUD REGION w/ MW EYE
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i have yet to track a nuetral year. 09 was El Nino, 10 and 11 were La Nina.
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Thanks Jeff, average 2012. Phew, no worries then...
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Everything you learned about weather in school is irrelevant because because people are making the weather now. Particulates dumped in the Pacific Ocean airshed work their way around the globe creating worldwide stagnation. If less sun hits the ocean and there is no lift, there will be less hurricanes. The global temperature will even out and the Earth atmosphere will become a stagnant pond.
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ADT says Hurricane Alenga
CI# /Pressure/ Vmax
4.5 / 973.5mb/ 77.0kt

Raw T# 3.0 <----------------?
Adj T# 4.5
Final T# 4.5

Weakening Flag: OFF <---------?

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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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