November Atlantic hurricane season outlook

By: Dr. Jeff Masters , 1:00 PM GMT on October 31, 2008

A small area of disturbed weather in the extreme southern Caribbean has brought heavy rains of up 4-6 inches to Costa Rica and southern Nicaragua over the past two days. This disturbance should persist for the next 3-5 days, and the UKMET and NOGAPS models continue to forecast that a tropical depression could form in this region 4-7 days from now. Steering currents are weak in the area, and any storm forming there would move slowly. Nicaragua would be at greatest risk from such a storm.

Late season Atlantic tropical storms
What are the odds of getting a late-season November or December tropical storm? In the active hurricane period that began in 1995, we've had nine tropical storms in November, and four in December, for an average of one late season storm per year. Six of these late season storms have become hurricanes. The record for late season named storms is four, which occurred in 2005, when three November and one December storm formed. The typical formation location for these late-season storms is the Western Caribbean or the middle Atlantic (Figure 1). The Western Caribbean storms are the most dangerous. There have been two Category 4 hurricanes that have formed in November in that region, Hurricane Lenny of 1999 (the strongest late-season hurricane on record, with 155 mph winds), and Hurricane Michelle of 2001. November storms are primarily a theat to Central America, Cuba, the Cayman Islands, the Bahamas, and the Gulf Coast of Florida.


Figure 1. Historical tropical cyclone tracks in the Atlantic for storms that formed in the first half of November. The Western Caribbean is the preferred formation region.

Sea Surface Temperatures
Sea Surface Temperatures (SSTs) are cooling, but are still warm enough to support a tropical storm over the Caribbean (Figure 1). The Gulf of Mexico will cool significantly in the coming week, due to the presence of cold air and northwesterly winds. It is now too late for the Gulf to spawn a tropical storm, and any hurricane or tropical storm that passes into the Gulf will likely weaken due to the cool SSTs there. The total heat content of the ocean is still high enough to support a major hurricane in the Caribbean.


Figure 2. Sea Surface Temperatures (SSTs) on October 29, 2008. The 26 ┬░C isotherm (red line that separates blue colors from yellow colors) marks the boundary where SSTs are warm enough to support a tropical storm. Image credit: NOAA/AOML.

Wind shear
High wind shear is main reason we don't get many November tropical storms. Wind shear is currently very high north of the Caribbean Sea, and is forecast to remain high for the next two weeks (Figure 3). However, shear is low over the Caribbean, and is forecast to remain low for at least the next two weeks.


Figure 3. Forecast wind shear (in meters per second) for Friday, November 7, at 06 GMT. This is an 8-day forecast generated by the 12Z GMT run of the GFS model on Thursday, October 30. The Caribbean is forecast to remain under low shear for the first half of November, while the U.S. will be protected by very high shear, thanks to the presence of the jet stream.

MJO
We are currently in the phase of the Madden-Julian Oscillation (MJO) that suppresses Atlantic tropical storm formation. The MJO is a pattern of enhanced rainfall that travels along the Equator, and can act to boost hurricane activity when it propagates into the Atlantic. The MJO has a period of about 30-60 days. According to the latest 15-day GFS model forecast and the MJO discussion from the National Weather Service's Climate Prediction Center, we are expected to remain in the inactive phase for the MJO for the next two weeks. By mid-November, we may transition to a positive MJO again. This year, the active phase of the MJO has been strongly correlated with formation of named storms in the Atlantic. Thus, the chances for a late-season named storm may increase by mid-November.

Summary
Given past climatology, warm SSTs in the Caribbean, and forecast low wind shear over the Caribbean for the first half of November, I put the odds at 50% we will see a named storm in the western or south-central Caribbean in the first half of November. Given the recent history of such storms, there is a 50% chance that such a storm would become a hurricane.

I'll update this blog over the weekend if there's any developments in the tropics worth reporting.

For those interested, the portlight.org charity now features a blog that details the recent Hurricane Ike relief effort they undertook.

Jeff Masters

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Quoting surfmom:
if your in FL-- check the MOON out -- neat set-up w/planet and stars BBL


thanks Mom, on my way to look now.
Member Since: August 24, 2008 Posts: 0 Comments: 320
Baha, I clicked on your name and looked at your WUnder Blog. You have a graphic and discussion of Hurricane Betsy. I was a young lass, living in Lafayette LA in 1965, and experienced Betsy. A very mean storm, she was.
Member Since: September 13, 2008 Posts: 9 Comments: 2953
That same moon/star set up is here too. (obviously) And it just crowNs a good day.
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So true, Baha.
How you keeping there ?
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if your in FL-- check the MOON out -- neat set-up w/planet and stars BBL
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Quoting BahaHurican:
Especially blogging. Drinking will at least potentially make you IMAGINE you have company . . . lol

LOL! Depends on the spirits....the kind in the bottle.
Member Since: September 13, 2008 Posts: 9 Comments: 2953
Quoting pottery:
Ahhh, that sounds nice Sugar. A lovely one here too, with showers on and off. At about 3 pm the sun was slanting in brightly, and it was raining, and every leaf in the garden had a precious jewel attached to it tip. Sparkles all around for an hour or so.


I love a sunshower. Especially this time of year when the temps are just perfect.
Member Since: August 24, 2008 Posts: 0 Comments: 320
Quoting sugarsand:
Pottery, by all means, no fun to blog and drink alone!
Especially blogging. Drinking will at least potentially make you IMAGINE you have company . . . lol
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Quoting sugarsand:
CapeO, what are your night temps?


It's been in the mid to lower 60's last couple nights. On the rise over the last week. It got down to the lower 40's after the front came through.
Member Since: August 24, 2008 Posts: 0 Comments: 320
Quoting pottery:
Ahhh, that sounds nice Sugar. A lovely one here too, with showers on and off. At about 3 pm the sun was slanting in brightly, and it was raining, and every leaf in the garden had a precious jewel attached to it tip. Sparkles all around for an hour or so.

Very nice!
Member Since: September 13, 2008 Posts: 9 Comments: 2953
CapeO, what are your night temps?
Member Since: September 13, 2008 Posts: 9 Comments: 2953
Ahhh, that sounds nice Sugar. A lovely one here too, with showers on and off. At about 3 pm the sun was slanting in brightly, and it was raining, and every leaf in the garden had a precious jewel attached to it tip. Sparkles all around for an hour or so.
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Quoting sugarsand:

That's what it looks like CapeO. We might get s leetle bit, but not like the east coast.


At this point we could use a little rain. With the cold, dry air of late and the wind, things are getting on the crispy side. Poor little trick or treaters were getting blown around pretty good last night.
Member Since: August 24, 2008 Posts: 0 Comments: 320
Quoting CapeObserver:
Good Evening all! What's up off the FL coast? Local guys saying we're gonna get wet.

That's what it looks like CapeO. We might get a leetle bit, but not like the east coast.
Member Since: September 13, 2008 Posts: 9 Comments: 2953
Good Evening all! What's up off the FL coast? Local guys saying we're gonna get wet.
Member Since: August 24, 2008 Posts: 0 Comments: 320
All is well here. A splendid day on the Gulf coast. November 1st and we hit 73 degrees with brilliant sunshine.
Member Since: September 13, 2008 Posts: 9 Comments: 2953
Pottery, by all means, no fun to blog and drink alone!
Member Since: September 13, 2008 Posts: 9 Comments: 2953
Yeah Sugar, we thumped the Brits. Now they have all run away it seems!
A truly Comprehensive Whalloping, as they say over there.
How are you on this fine evening/
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Quoting RobDaHood:
378. BahaHurican

who is the author, I'll keep a lookout.
Sorry for the wait. The guy is named Chester Thompson.

Link
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Hello, Sugar. Mind if I pull up a chair? I've got me own toddy....
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Hey Pottery, they were looking for you earlier. Re: Cricket game?
Member Since: September 13, 2008 Posts: 9 Comments: 2953
GLOAT< GLOAT< GLOAT--where is Cotillion LOL
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I'm back! Boys fed,dogs fed, and I have my toddy. Anybody here? Weather looks to be brewing off the east coast of Fl/Ga. Don't think we'll get too much on the Emerald Coast.
Member Since: September 13, 2008 Posts: 9 Comments: 2953
Okay, after 8 and the "blogger girlz" still haven't shown up for happy hour. And where is that "pottery guy"? Growing weary of sippin my rum alone so will go and watch a DVD for a while. Will check in periodically
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Time to wander off, busy day tomorrow.

Night all.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting BahaHurican:
How busy we get depends on US economy. This fall has been the slowest in prolly decades. Only good thing for us is that we are still within relatively inexpensive reach of the Eastern Seaboard.


Yeah, you are probably more closely tied to the economy because of tourism...we get the retirees no matter what. Gas prices are WAY down here right now. Also notice a lot of new heavy equipment (dozers, trackhoes, loaders, big ticket items) on the road this week as well as a lot of trucks. Encouraging signs.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
388. RobDaHood 4:46 PM PDT on November 01, 2008
Quoting Tazmanian:
dont for get to set your clocks back 1 hr tonight be for you go too bed or you could be late for work come sunday and monday AMs


Thanks Taz! Better Back than forward!



your welcome
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Quoting RobDaHood:


Sounds like all the makings of a busy tourist season!?

Noticed this week traffic really picking up in FL after that first cold snap!
How busy we get depends on US economy. This fall has been the slowest in prolly decades. Only good thing for us is that we are still within relatively inexpensive reach of the Eastern Seaboard.
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Huh?
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Quoting Tazmanian:
dont for get to set your clocks back 1 hr tonight be for you go too bed or you could be late for work come sunday and monday AMs


Thanks Taz! Better Back than forward!
Member Since: September 2, 2008 Posts: 119 Comments: 42160
dont for get to set your clocks back 1 hr tonight be for you go too bed or you could be late for work come sunday and monday AMs
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385. MichaelSTL

it did penetrate pretty far south,

being the operative words from our perspective...a neighbor told me that it ran him out of GA, LOL
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Know very little about cricket and such, but do admit to getting a tad nervous watching your Aston Martins sparing with our Saleens and 'Vettes for the FIA championships every year. Yeah, big automotive nut.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
382. Cotillion

Yes, it would.

yeah, 3 points for me.

and I agree, Pottery should be showing up to gloat, and perhaps brat as well.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Quoting RobDaHood:


Sorry, ignorant bloody yank here, that would be cricket? Destroyed by who?


Yes, it would. And by the 'Stanford Superstars XI' basically a collection of West Indies players. They're playing for a $1 million each. So England, as is customary, capitulate. However, they're not really playing for any national pride, just for their own gain.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting Cotillion:
I'm sure Pottery will be amused. England's 20/20 team are getting absolutely destroyed...


Sorry, ignorant bloody yank here, that would be cricket? Destroyed by who?
Member Since: September 2, 2008 Posts: 119 Comments: 42160
I'm sure Pottery will be amused. England's 20/20 team are getting absolutely destroyed...
Member Since: August 23, 2008 Posts: 7 Comments: 5300
378. BahaHurican

who is the author, I'll keep a lookout.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Quoting RobDaHood:
372. BahaHurican

sounds like an interesting read. Title sounds familiar, but don't remember having read it.
I'm looking around to see if it's still in print. The copy I'm reading is a borrowed one, and I think I'd like to own it. The writing isn't all that complex, but it captures the atmosphere and local colour very well.
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Quoting BahaHurican:
1. On today's weather: we had a GREAT day in Nassau - mostly sunny until later in the afternoon, when the high altostratus clouds were actually somewhat appreciated for keeping the temps from getting too hot, and a moderate breeze.

2. On forecasted weather for the winter: With this cold a snap this early, we may be in for a chilly winter. Everybody's talking about pulling out the coats for a "real" winter . . . lol


Sounds like all the makings of a busy tourist season!?

Noticed this week traffic really picking up in FL after that first cold snap!
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Quoting CybrTeddy: Cayman Brac in the Cayman Islands also gto severly trashed in 1932 and several deaths although people who were around for that and for Ivan in 2004 said Ivan was a lot worse.
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Wow, sunset is stunning tonight, and girlfriend has my camera up north.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
1. On today's weather: we had a GREAT day in Nassau - mostly sunny until later in the afternoon, when the high altostratus clouds were actually somewhat appreciated for keeping the temps from getting too hot, and a moderate breeze.

2. On forecasted weather for the winter: With this cold a snap this early, we may be in for a chilly winter. Everybody's talking about pulling out the coats for a "real" winter . . . lol
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372. BahaHurican

sounds like an interesting read. Title sounds familiar, but don't remember having read it.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Quoting Cotillion:
To add on, that storm of 1932 is interesting because of other things. And, I quote:

"While the storm is currently listed in the HURDAT as a marginal Category 4 hurricane on the Saffir-Simpson hurricane scale with no listed pressure,[3] according to the Hurricane Reanalysis Project the hurricane likely reached Category 5 intensity with 160 mph (260 km/h) winds when it made landfall in Cuba with a minimum central pressure of 915 mbar.[4] If that were determined to be correct, it would be the latest Category 5 hurricane ever recorded in the Atlantic basin, surpassing Hurricane Hattie of the 1961 season by six days. It would also easily be the strongest storm (and only Category 5 hurricane) ever recorded in the month of November, well ahead of Hurricane Lenny's 933 mbar pressure. In addition, such an upgrade would make the 1932 season the first of five seasons with multiple Category 5 hurricanes, joining the 1960, 1961, 2005 and 2007 seasons; additionally, this such upgrade would also make the 1932 season the first Atlantic hurricane season to have multiple Category 5 landfalls, an event only repeated by the 2007 season."

Link
Interesting that you should mention this. 1932's storm is used as one of the models for the introduction of a a novel I'm reading right now called The Fledgling. The writer, an Abaconian native, lightly fictionalizes his own biography to create a vignette of life on Elbow Cay, Abaco in the 20s and 30s. Of course, the 1920s and 30s were in the middle of the last "busy" period stormwise.
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Cutting the pundits/politicos some slack - its only once in a while & they think its important. It could be weather related.
Remember QS needs a replacement. How were you going to get it up there?
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Quoting RobDaHood:


You asked about the barbie last night, hope you caught my reply...anytime you're in the neighborhood, drop me a note.


Should I ever be, I may well do that.

And anyway, be thankful it's not Gore vs McCain. I really think some people would implode if that happened.

Y'all come over to England, a day after the elections. Big bonfire, fireworks and lots of food. Perfect way to celebrate the ending of the political season. ;)
Member Since: August 23, 2008 Posts: 7 Comments: 5300
Quoting JupiterFL:

I stood in line for an hour yesterday and loved every minute of it. I had an hour to think about how lucky I was to live in a country where I can vote. I didn't have to worry about getting shot at or fights breaking out in line. The local news lady was in front of me. She has had breast cancer for a couple of years now. Some of you may know who she is. When you see people that fight everyday like she does, it makes me feel even more blessed. All I could do was think about my life, my family and my great country. God bless America.
If you HAVE to post politics, this is the way to do it . . . smooth, Jupe. . .

I am convinced American elections can be more efficent and fair than they are right now. Also, why is it that all those other things beside the presidency and bicameral votes on the ballot? (OK, that's really rhetorical, but I'm going to have to read elsewhere to find out why that's done. . . )

Anyway that is the absolutely last political comment I am making in here before the election . . . .
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Quoting Cotillion:


Ah, I'm envious!

A bit of warmth would be nice, though Bonfire Night is a-comin', nothing like standing outside watching fireworks in the blistering cold.


You asked about the barbie last night, hope you caught my reply...anytime you're in the neighborhood, drop me a note.
Member Since: September 2, 2008 Posts: 119 Comments: 42160
Quoting RobDaHood:


Abso-freekin-lutely fan-tab-ulous!

60 - 80 range and no rain although we may get a little over the next couple days.


Ah, I'm envious!

A bit of warmth would be nice, though Bonfire Night is a-comin', nothing like standing outside watching fireworks in the blistering cold.
Member Since: August 23, 2008 Posts: 7 Comments: 5300

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Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather

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