Record Atlantic SSTs continue in the hurricane Main Development Region

By: Dr. Jeff Masters , 8:03 PM GMT on May 15, 2010

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Sea Surface Temperatures (SSTs) in the Atlantic's Main Development Region for hurricanes had their warmest April on record, according to an analysis of historical SST data from the UK Hadley Center. SST data goes back to 1850, though there is much missing data before 1910 and during WWI and WWII. The area between 10°N and 20°N, between the coast of Africa and Central America (20°W - 80°W), is called the Main Development Region (MDR) because virtually all African waves originate in this region. These African waves account for 85% of all Atlantic major hurricanes and 60% of all named storms. When SSTs in the MDR are much above average during hurricane season, a very active season typically results (if there is no El Niño event present.) SSTs in the Main Development Region (10°N to 20°N and 20°W to 85°W) were an eye-opening 1.46°C above average during April. This is the third straight record warm month, and the warmest anomaly measured for any month--by a remarkable 0.2°C. The previous record warmest anomalies for the Atlantic MDR were set in June 2005 and March 2010, at 1.26°C.


Figure 1. The departure of sea surface temperature (SST) from average for May 13, 2010. Image credit: NOAA/NESDIS.

What is responsible for the high SSTs?
As I explained in detail in a post on record February SSTs in the Atlantic, the Arctic Oscillation (AO) and its close cousin, the North Atlantic Oscillation (NAO), are largely to blame for the record SSTs. The AO and NAO are climate patterns in the North Atlantic Ocean related to fluctuations in the difference of sea-level pressure between the Icelandic Low and the Azores-Bermuda High. If the difference in sea-level pressure between Iceland and the Azores is small (negative NAO), this creates a weak Azores-Bermuda High, which reduces the trade winds circulating around the High. During December - February, we had the most negative AO/NAO since records began in 1950, and this caused trade winds between Africa and the Lesser Antilles Islands in the hurricane Main Development Region to slow to 1 - 2 m/s (2.2 - 4.5 mph) below average. Slower trade winds mean less mixing of the surface waters with cooler waters down deep, plus less evaporational cooling of the surface water. As a result, the ocean heated up significantly, relative to normal, over the winter. Negative AO/NAO conditions have been dominant much of this spring as well, resulting in further anomalous heating of the MDR waters. This heating is superimposed on the very warm global SSTs we've been seeing over the past few decades due to global warming. Global and Northern Hemisphere SSTs were the 2nd warmest on record this past December, January, and February, the warmest on record in March, and will likely be classified as the warmest or second warmest on record for April, since NASA just classified April as the warmest April on record for the globe. We are also in the warm phase of a decades-long natural oscillation in Atlantic ocean temperatures called the Atlantic Multi-decadal Oscillation (AMO). This warm phase began in 1995, and has been partially responsible for the high levels of hurricane activity we've seen since 1995.

What does this imply for the coming hurricane season?
The high April SST anomaly does not bode well for the coming hurricane season. The three past seasons with record warm April SST anomalies all had abnormally high numbers of intense hurricanes. Past hurricane seasons that had high March SST anomalies include 1969 (0.90°C anomaly), 2005 (1.19°C anomaly), and 1958 (0.97°C anomaly). These three years had 5, 7, and 5 intense hurricanes, respectively. Just two intense hurricanes occur in an average year. The total averaged activity for the three seasons was 15 named storms, 11 hurricanes, and 6 intense hurricanes (an average hurricane season has 10, 6, and 2.) Both 1958 and 2005 saw neutral El Niño conditions, while 1969 had a weak El Niño.

The SSTs are already as warm as we normally see in July between Africa and the Caribbean, and we have a very July-like tropical wave approaching the Lesser Antilles Islands this weekend. However, wind shear is still seasonably high, and the tropical waves coming off of Africa are still too far south to have much of a chance of developing. The GFS model is indicating that shear will start to drop over the Caribbean the last week of May, so we may have to be on the watch for tropical storms forming in the Caribbean then.

For those of you interested in a more detailed look at the early season tropical weather outlook, consult the excellent wunderblogs of StormW and Weather456. I'll be back with a new post on Monday.

Jeff Masters

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Quoting KEEPEROFTHEGATE:
yeah as more jump on board the chances increases with its outcome
Yeah especially the ECMWF. I think that will be the model to follow in 2010, imo.
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Quoting MiamiHurricanes09:
The wave east of Trinidad needs to be followed because that's probably going to be the season first TD or TS, as per models.


still to early to call...but it will be monitored as it heads west.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting KEEPEROFTHEGATE:
anytime after the 20th between 21st and 23rd
with 23rd being the best chance of them all
once runs get down to 96 hr mark
we will know a little more
as we get closer and closer
Well the 20th of May is 96 hours away.
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Quoting MiamiHurricanes09:
That's pretty intense. A 1000 MB low. I hear that the euro and nogaps are suggesting development now?
yeah as more jump on board the chances increases with its outcome
Member Since: July 15, 2006 Posts: 163 Comments: 52257
865. xcool
REALL SOON HERE WE GO
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Quoting IKE:


Season is fixing to get started...real soon.
anytime after the 20th between 21st and 23rd
with 23rd being the best chance of them all
once runs get down to 96 hr mark
we will know a little more
as we get closer and closer
Member Since: July 15, 2006 Posts: 163 Comments: 52257
The wave east of Trinidad needs to be followed because that's probably going to be the season first TD or TS, as per models.
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Quoting KEEPEROFTHEGATE:
for guidance purposes only
That's pretty intense. A 1000 MB low. I hear that the euro and nogaps are suggesting development now?
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861. IKE
Quoting xcool:
SUNDAY NOON
Videos on line today.

The Long ( danger) ranger looks at the developing large scale upward motion pattern in the Caribbean and possible development implications. I show the trough split that attempts to take place and then the start of the kind of retrogression that may get the tropics involved in southeast US weather the first week of June

BY JOE


Season is fixing to get started...real soon.
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860. xcool
UPDATE BY:Jim Williams.....I am currently preparing for the hurricanecity kick-off show for June 1st at 8:00PM ET on hurricane TV . Each year I pick what cities and Islands I think have a chance to be affected based on return rates and other trends. With the exception of last year I have done very well especially my top 5 locations. I will have more on the upcoming show as the hurricane season closes in.
Member Since: September 26, 2009 Posts: 2 Comments: 15603
859. xcool
SUNDAY NOON
Videos on line today.

The Long ( danger) ranger looks at the developing large scale upward motion pattern in the Caribbean and possible development implications. I show the trough split that attempts to take place and then the start of the kind of retrogression that may get the tropics involved in southeast US weather the first week of June

BY JOE
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Well, my original guess was for 15 named storms, 11 hurricanes, 4 major.

But I also think there will be 45 invests, too.
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Does anyone have a good site for historical SST maps? Such as the Caribbean during Hurricane Mitch of 1998? Much appreciated.
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855. xcool
and ngp tooo
Member Since: September 26, 2009 Posts: 2 Comments: 15603
I see the Euro is showing development. Let's see if it keeps it. One thing for sure, broad area of low pressure will develop over the area.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
853. xcool



hey 'Ladies and gentlemen,
Member Since: September 26, 2009 Posts: 2 Comments: 15603
852. IKE
Sunday 12Z ECMWF...
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for guidance purposes only
Member Since: July 15, 2006 Posts: 163 Comments: 52257
Off to see the grass roots at annual Greynolds Park Love-in. North east Dade County Park. Have a nice afternoon everyone. Peace out.
Member Since: August 18, 2008 Posts: 0 Comments: 3109
Quoting JRRP:

here is the 12z
Link


Thats yesterday's run.
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848. JRRP
Quoting Stormchaser2007:
ECMWF on board for tropical mischief in the Caribbean.

00z at 240 hours

here is the 12z
Link
Member Since: August 16, 2007 Posts: 0 Comments: 5079
nw atl wv image as of 301 pm 6 mins old

Member Since: July 15, 2006 Posts: 163 Comments: 52257
ECMWF on board for tropical mischief in the Caribbean.

00z at 240 hours
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Just read that they got that pipe in the broke pipe. So did they say how much oil they are able to bring up to the ships now?
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Hey Everyone:

I'm back in New Mexico and will be home in a couple of hours. Gotta stop for some chicken for dinner.

Front page of The Weather Channel...pretty cool...but I did sell the footage, so I expected it. I'm delighted that it is one of the most popular videos on there today.

Good Luck to tornadodude. I hope he and his friend stay safe. If he gets any good footage, it will make it to The Weather Channel, too! :)

Happy Hunting, Matt! :)

Oz---out!
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843. Skyepony (Mod)
"Twister" Farm Destroyed
Sunday May 16, 2010

The successful but often cringe-worthy 1996 film "Twister" featured flying CGI cows, the talented Philip Seymour Hoffman in perhaps his only uninteresting performance to date and a Jami Gertz character that can best be described as painfully irritating. Nevertheless, and despite the fact that it's filled with plenty of stereotypes about us, it is embraced as one of the most well-known movies to feature Oklahoma.

And apparently, in one of the stranger stories to come out of this past week's events, the Michael Crichton-penned blockbuster is also somewhat prophetic.

A farm near Fairfax where one of the key tornado scenes in the movie takes place was hit by the real thing during last Monday's storms. Perhaps you remember it in the movie, when Helen Hunt and Bill Paxton go off-road and barely escape the funnel by diving under a small bridge. According to farm owner J. Berry Harrison Sr., Monday's twister followed the exact path of the one in the movie, destroying the silos from that scene along with two houses and several barns.
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heard part of the spill could start getting in the loop current in about 4 days from now!!!!,not good news...
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Well done Greyelf!
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840. JRRP
June 1
shear forecast
Member Since: August 16, 2007 Posts: 0 Comments: 5079
826. StormW 6:07 PM GMT on May 16, 2010 Hide this comment.

Quoting calder:
hi, frequent visitor to the blog but looking for some info. Have a degree in aeronautical engineering and about to graduate in my 2nd degree in geophysics and meteorology. My girlfriend is moving to the US and I was wondering what the prospects of finding a met job in the states if im from the UK?

thanks for any help



Let me check around for you...I am a member of the West Central Florida, AMS, and know the Meteorologist in Charge at the NWS Ruskin FL. office...see if he can give me any info.


many thanks
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Quoting RTLSNK:
I wonder if BP was using one of these originally?


BP CANT REPEL OIL OF THAT MAGNITUDE!!
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Quoting Greyelf:
There's a couple of Wunderground people on the TWC front page...the "iWitness Weather" picture called "Sunrise in Bellevue" was submitted by me.



That's great. Kudos man...
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Quoting tornadodude:


Thats pretty awesome!!


Yeah, be careful Matt. Conditions look right in the Abilene area for possible severe conditions.
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There's a couple of Wunderground people on the TWC front page...the "iWitness Weather" picture called "Sunrise in Bellevue" was submitted by me.

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834. Skyepony (Mod)
Torn~ if you click the pic (I got it fixed) it goes to the Mr T Storm Chasin School..best comic ever..
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Quoting hurricanejunky:
This may be redundant but Cyclone Oz made the Weather Channel's front page:

Close call for storm chaser


Thats pretty awesome!!
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Why in Houston????
Did they make another command post?


Taco :o)
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831. DDR
456
The Trades are pushing some your way.XD
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830. DDR
Quoting pottery:

Yeah. And once it starts, its going to go for a while. There is plenty coming behind this leading edge. It is being blocked by the wind-wall right now.

You can see the shear riping the storm tops off and pushing them NE,still we'll get plenty within the next 48 hrs.
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Quoting DDR:
Hey
Your right,because most of it is high clouds.
Maybe tonight...I see your watch the game.My money is on England


the bulk of the rain should arrive on Monday
Member Since: July 24, 2005 Posts: 407 Comments: 19076
DATE: May 16, 2010 12:44:28 CST


MEDIA ADVISORY: BP to hold media briefing in Houston



Deepwater Horizon Incident
Joint Information Center

Phone: (985) 902-5231
(985) 902-5240

WHO: BP Senior Executive Vice-President Kent Wells

WHAT: BP technical briefing and update on Gulf of Mexico oil spill response.

WHERE: BP, 200 Westlake Park Blvd, Unit 4, Houston, TX 77079.

WHEN: 1:30 p.m. CDT, Sunday, May 16

*Please be in main reception no later than 1:15 p.m. CDT. This is a pen and paper briefing only. No video or still cameras will be allowed inside the briefing. Pooled video will be supplied.

Participant Dial-in US/Canada: (877) 341-5824
International callers use: (706) 758-0885

Conference ID: 76271936

RSVP: Media interested in attending should call (281) 366-6965.

For information about the response effort, visit www.deepwaterhorizonresponse.com.
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Quoting Skyepony:


Keep an eye out for Mr T & Cyclone Oz..
<>img src=http://www.stormtrack.org/humor/mrt2/12.jpg width=450>



hahaha thanks :)
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Out for a while...
Member Since: October 24, 2005 Posts: 0 Comments: 23080
Quoting DDR:
Hey
Your right,because most of it is high clouds.
Maybe tonight...I see your watch the game.My money is on England

Yeah. And once it starts, its going to go for a while. There is plenty coming behind this leading edge. It is being blocked by the wind-wall right now.
Member Since: October 24, 2005 Posts: 0 Comments: 23080
well actually heading to the Oklahoma City area to hopefully find some hail

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822. DDR
Hey
Quoting pottery:

Looks pretty ominous in that image.
No sign of that from here, on the ground.

Your right,because most of it is high clouds.
Maybe tonight...I see your watch the game.My money is on England
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821. Skyepony (Mod)
Quoting tornadodude:
well actually heading to the Oklahoma City area to hopefully find some hail



Keep an eye out for Mr T & Cyclone Oz..
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Shuttle Atlantis Pitch Maneuver as it makes rendezvous with ISS.

At :45 secs into the video the GOM Oil Spill is seen as the ISS and Atlantis Zoom's overhead it..
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Quoting Weather456:
I'm routing for you guys


Looks pretty ominous in that image.
No sign of that from here, on the ground.
Member Since: October 24, 2005 Posts: 0 Comments: 23080

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About JeffMasters

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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