November Atlantic hurricane season outlook

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

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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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617. Seastep
7:56 PM GMT on June 26, 2009
12 above

Quoting cchsweatherman:
Been soul-searching over the past week and have been through war in my mind. Through this, I have discovered that I have so much that I need to straighten out mentally. So, I have made the difficult decision to step aside from weather forecasting indefinitely and will not be updating my website for quite some time. Just send me a message if you have any response since I don't want comments to clog the blog. I hope you will all understand this move. Have a great weekend and look forward to returning in the future.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
616. Orcasystems
5:33 PM GMT on November 02, 2008
New Blog
Member Since: October 1, 2007 Posts: 81 Comments: 26511
615. Orcasystems
5:20 PM GMT on November 02, 2008
Hurricane Michelle was a powerful hurricane that impacted portions of the Caribbean and Bahamas in November, 2001. Michelle is one of only four Category Four hurricanes to occur in the month of November. A tropical wave moved off the coast of Africa on October 16th and moved westward. It remained disorganized until reaching the Western Caribbean Sea, when favorable conditions allowed it to develop into a tropical depression, on October 29th. It made landfall in Nicaragua on the 30th, and drifted to north over Honduras. The center moved back over the Caribbean Sea on the 31st, and the system reached tropical storm strength on November 1st. Over the Western Caribbean, Michelle continued to strengthen, and reached hurricane strength on November 2nd. Rapid intensification ensued, and 30 hours later, Michelle reached Category Four strength with sustained winds of 135 mph. After fluctuating in intensity, while drifting to the northeast, Michelle peaked with 140 mph winds and a central pressure of 933 mb, making landfall near Bay of Pigs, Cuba on the 4th. Michelle rapidly weakened over the mountainous terrain, and accelerated to the northeast. By mid-morning on November 5th, the storm had weakened to 85 mph as it was racing through the Bahamas. Michelle became extra-tropical early on the 6th, and was absorbed by a strong frontal system that night. At the time, Hurricane Michelle was the strongest hurricane to directly impact Cuba since Hurricane Fox in 1952. Michelle was responsible for 17 fatalities and $2 Billion (2001 USD), $2.17 Billion (2005 USD) in damage across Central America, Cuba and the Bahamas.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
614. Cotillion
5:18 PM GMT on November 02, 2008
Quoting Vortex95:
Theres been quite a bit of TC's this season only 6 names are left.


Only '69, '95, '03 and '05 have more active since 1950 in terms of # of tropical storms.

Aren't too many before that, either. (Can't remember the site with the list and ACE list from 1851-2007.)


Member Since: August 23, 2008 Posts: 7 Comments: 5300
613. Orcasystems
5:17 PM GMT on November 02, 2008
Quoting Vortex95:
Thats errie the CMC run has a track similar to the first half of the track for 2001 michelle


Oh sure..stir the pot....

Member Since: October 1, 2007 Posts: 81 Comments: 26511
609. Orcasystems
5:11 PM GMT on November 02, 2008
If you follow and believe the CMC has done very well this year.. then the season is not over by a long shot.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
608. Orcasystems
5:09 PM GMT on November 02, 2008
Quoting Vortex95:
Orca that CMC run looks nothing like the model run I saw...

anyways gonna be an interesting week if somthing develops.


The 00z is older then the 12Z. The link on my page is the 00Z run. They agree on most of it.. but the 12Z has the second system developing.. where as the 00Z has it starting.. then dieing off.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
607. Skyepony (Mod)
5:05 PM GMT on November 02, 2008
Had over 2" of rain in Melbourne, FL in the last 24hrs. Has a tropical look & a noreaster feel but not as cold as yesterday. It's been the kind of rain the SE needs more of these days.. no ponding but plentiful. Different set up with a cutt off ULL coming down & the trough. Had the pwats been higher it could have been severe.
Member Since: August 10, 2005 Posts: 162 Comments: 37810
604. Orcasystems
5:01 PM GMT on November 02, 2008
Quoting stoormfury:
something in an area in the south western carib near 13n 80w wants to form into something. there is a high degree of convergence and this could be the area that the models have been hinting all along of some form of cyclogenesis this week




Click to enlarge
Member Since: October 1, 2007 Posts: 81 Comments: 26511
603. stoormfury
4:57 PM GMT on November 02, 2008
an area in the south western carib near 13n 80w wants to form into something. there is a high degree of convergence and this could be the area that the models have been hinting all along of some form of cyclogenesis this week
Member Since: August 22, 2006 Posts: 0 Comments: 2674
602. Cotillion
4:56 PM GMT on November 02, 2008
Quoting Orcasystems:


I must admit, looking forward to the chat here Tuesday night.. unless there is a full blown Cat 2 roaring thru somewhere.. its going to be hilarious on here.


Ah shame I'll be missing it... :P
Member Since: August 23, 2008 Posts: 7 Comments: 5300
601. Orcasystems
4:49 PM GMT on November 02, 2008
Complete Refresh Blog
Mirror Site

Present Satellite, Area of Interest Southern Caribbean
Member Since: October 1, 2007 Posts: 81 Comments: 26511
600. Orcasystems
4:48 PM GMT on November 02, 2008
Quoting RobDaHood:


Getting afraid of a permanent fork in it (tongue) - lol

there are 2 interesting features in the carib/gom to argue/forecast/wishcast/dreamcast about. Should be plenty.

Cooking duties calling...


I must admit, looking forward to the chat here Tuesday night.. unless there is a full blown Cat 2 roaring thru somewhere.. its going to be hilarious on here.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
599. RobDaHood
4:46 PM GMT on November 02, 2008
Quoting Orcasystems:


Well something has to happen soon.. or they will start on Politics again.. then you will hurt yourself again bitting your tongue


Getting afraid of a permanent fork in it (tongue) - lol

there are 2 interesting features in the carib/gom to argue/forecast/wishcast/dreamcast about. Should be plenty.

Cooking duties calling...
Member Since: September 2, 2008 Posts: 96 Comments: 31874
598. Orcasystems
4:41 PM GMT on November 02, 2008
Texas floats plan to house Ike victims aboard ship
Member Since: October 1, 2007 Posts: 81 Comments: 26511
597. Orcasystems
4:35 PM GMT on November 02, 2008
Quoting CybrTeddy:


Didn't you say after Marco that 'No more storms for 2008' and a Category 4, a Tropical Storm and a Tropical Depression popped up in a week.


Yup, he did
Member Since: October 1, 2007 Posts: 81 Comments: 26511
596. Orcasystems
4:35 PM GMT on November 02, 2008
Quoting RobDaHood:
RE: Carib possible system.

I've been looking at this one this morning. Most of the pieces are in place, converg/diverge, warm water, shear not prohibitive but seems to be building a little and may be the limiting factor. Think that UUL (which seems to be building nicely and translating into mid levels) will be a factor in the future of this system.

Having said that, I still would not be surprized to see this end up in the EPAC. No real basis for that, haven't developed a real feeling for it yet.


Well something has to happen soon.. or they will start on Politics again.. then you will hurt yourself again bitting your tongue
Member Since: October 1, 2007 Posts: 81 Comments: 26511
595. CybrTeddy
4:33 PM GMT on November 02, 2008
Quoting Tazmanian:
i will eat one crow for evere storm thats pops up in tell the end of nov be come i do not see any more name storms for 2008


Didn't you say after Marco that 'No more storms for 2008' and a Category 4, a Tropical Storm and a Tropical Depression popped up in a week.
Member Since: July 8, 2005 Posts: 259 Comments: 23882
594. RobDaHood
4:32 PM GMT on November 02, 2008
RE: Carib possible system.

I've been looking at this one this morning. Most of the pieces are in place, converg/diverge, warm water, shear not prohibitive but seems to be building a little and may be the limiting factor. Think that UUL (NE GOM which seems to be building nicely and translating into mid levels) will be a factor in the future of this system.

Having said that, I still would not be surprized to see this end up in the EPAC. No real basis for that, haven't developed a real feeling for it yet.
Member Since: September 2, 2008 Posts: 96 Comments: 31874
593. Seastep
4:19 PM GMT on November 02, 2008
Orca - That's what I was thinking.

Think we have yellow @ 2pm unless sat presentation changes significantly.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
592. KEEPEROFTHEGATE (Mod)
4:18 PM GMT on November 02, 2008
Quoting PensacolaDoug:
So far the NHC isn't showing any love for the CARRIB system. Looking impressive on sat tho.
My guess is they will circle it soon.
its a area of interest
est pos
14.9n/79.8w
Member Since: July 15, 2006 Posts: 170 Comments: 53526
591. Cotillion
4:16 PM GMT on November 02, 2008
The next TWO may have something to say.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
590. Orcasystems
4:13 PM GMT on November 02, 2008
Quoting PensacolaDoug:
So far the NHC isn't showing any love for the CARRIB system. Looking impressive on sat tho.
My guess is they will circle it soon.


And still no circle.. go figure?

THIS SURFACE LOW HAS RECENTLY DEVELOPED BASED ON LOW LEVEL CYCLONIC CIRCULATION EVIDENT IN SATELLITE IMAGERY AND A RECENT QUIKSCAT PASS. SURFACE PRESSURE FALLS HAVE BEEN NOTED IN THE VICINITY OF THIS LOW...ALONG WITH CYCLONIC CURVATURE IN THE WIND FIELD FROM SURFACE OBSERVATIONS.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
589. RobDaHood
4:11 PM GMT on November 02, 2008
575. hurristat

I don't mean to play devil's advocate

Yes you do...LOL
Member Since: September 2, 2008 Posts: 96 Comments: 31874
588. Orcasystems
4:04 PM GMT on November 02, 2008
Quoting hurristat:


that's revolutionary, Orca!


Its good to see your living up to your living up to your nickname WOBW :)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
587. PensacolaDoug
4:04 PM GMT on November 02, 2008
So far the NHC isn't showing any love for the CARRIB system. Looking impressive on sat tho.
My guess is they will circle it soon.
Member Since: July 25, 2006 Posts: 0 Comments: 556
586. hurristat
4:03 PM GMT on November 02, 2008
Quoting Orcasystems:


I agree that it will be the Caribbean. It may even get named.


that's revolutionary, Orca!
Member Since: October 15, 2008 Posts: 11 Comments: 2312
585. hurristat
4:01 PM GMT on November 02, 2008
Quoting Cotillion:


I hope not. Both R storms we've seen have been retired.


I know this is kind of strange coming from me after yelling at Taz, but if we get a Rene, i see it as a Laura/Jerry type storm, short-lived and weak.
Member Since: October 15, 2008 Posts: 11 Comments: 2312
584. Orcasystems
4:01 PM GMT on November 02, 2008
Quoting Cotillion:


I hope not. Both R storms we've seen have been retired.


I agree that it will be the Caribbean. It may even get named.
Member Since: October 1, 2007 Posts: 81 Comments: 26511
583. hurristat
4:00 PM GMT on November 02, 2008
Quoting hurricanemaniac123:


It'll mostly likely be in the caribbean. We might get even get to Rene this season.


I answered your question...
Member Since: October 15, 2008 Posts: 11 Comments: 2312
582. Cotillion
3:57 PM GMT on November 02, 2008
Quoting hurricanemaniac123:


It'll mostly likely be in the caribbean. We might get even get to Rene this season.


I hope not. Both R storms we've seen have been retired.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
581. hurricanemaniac123
3:56 PM GMT on November 02, 2008
Quoting Orcasystems:


I will agree..and say within the next two weeks


It'll mostly likely be in the caribbean. We might get even get to Rene this season.
Member Since: September 21, 2008 Posts: 9 Comments: 688
580. Orcasystems
3:55 PM GMT on November 02, 2008
Has anyone started a straw poll/vote on their blog for this thing across the border yet?
Member Since: October 1, 2007 Posts: 81 Comments: 26511
579. Orcasystems
3:52 PM GMT on November 02, 2008
Quoting Cotillion:
I think we'll have at least one more storm. I won't elaborate anymore than that!


I will agree..and say within the next two weeks
Member Since: October 1, 2007 Posts: 81 Comments: 26511
578. Cotillion
3:51 PM GMT on November 02, 2008
I think we'll have at least one more storm. I won't elaborate anymore than that!
Member Since: August 23, 2008 Posts: 7 Comments: 5300
576. Orcasystems
3:48 PM GMT on November 02, 2008
Quoting Cotillion:


You poor souls. Fosters is nasty.


Agreed... try Canadian Beer instead :)
Member Since: October 1, 2007 Posts: 81 Comments: 26511
575. hurristat
3:47 PM GMT on November 02, 2008
Quoting Tazmanian:
i will eat one crow for evere storm thats pops up in tell the end of nov be come i do not see any more name storms for 2008


I don't mean to play devil's advocate, but it's not over 'til it's over. Don't declare the season's death while it's still alive. You may just eat your words (pun intended).
Member Since: October 15, 2008 Posts: 11 Comments: 2312
574. Tazmanian
3:44 PM GMT on November 02, 2008
i will eat one crow for evere storm thats pops up in tell the end of nov be come i do not see any more name storms for 2008
Member Since: May 21, 2006 Posts: 5091 Comments: 114920
573. TexasWynd
3:42 PM GMT on November 02, 2008
Ya know sometimes I think its best for John McCain not to smile. For some reason it really bothers me. Its just plain scary, a smile and 2 thumbs up. At the moment for the record I am at a toss up.
Member Since: October 6, 2007 Posts: 0 Comments: 76
572. Seastep
3:41 PM GMT on November 02, 2008
Good morning all.

Think we may have a storm brewing in the south central carib. Sat and Quikscat look good. QS from last night got the entire area and there was definitely a circulation. CMC, both fsu's and UK in agreement:


Models:

Link

Sat:

Link

QuikScat:

Link

8AM discussion:

CARIBBEAN SEA...
AN UPPER RIDGE AXIS EXTENDS FROM THE NE CARIBBEAN NEAR 16N62W TO
NW VENEZUELA NEAR 11N69W...WITH ANTICYCLONIC FLOW AROUND THE
RIDGE COVERING MUCH OF THE CARIBBEAN. DEEP MOISTURE AND UPPER
LEVEL DIVERGENCE W OF THE UPPER RIDGE ARE SUPPORTING SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 11N-19N BETWEEN
75W-83W. THIS CONVECTION IS BEING ENHANCED BY LOW LEVEL
CONVERGENCE IN THE VICINITY OF A SURFACE TROUGH OVER THE SW
CARIBBEAN THAT EXTENDS FROM 16N82W TO A 1010 MB SURFACE LOW AT
11N79W TO 9N77W. THIS SURFACE LOW HAS RECENTLY DEVELOPED BASED
ON LOW LEVEL CYCLONIC CIRCULATION EVIDENT IN SATELLITE IMAGERY
AND A RECENT QUIKSCAT PASS. SURFACE PRESSURE FALLS HAVE BEEN
NOTED IN THE VICINITY OF THIS LOW...ALONG WITH CYCLONIC
CURVATURE IN THE WIND FIELD FROM SURFACE OBSERVATIONS. DEEP
LAYER DRY AIR E OF THE UPPER RIDGE IS RESULTING IN MAINLY FAIR
WEATHER ACROSS THE E CARIBBEAN CONDITIONS. ALSO...DEEP LAYER DRY
AIR IN THE BASE OF THE UPPER TROUGH OVER THE GULF OF MEXICO IS
MOVING INTO THE FAR NW CARIBBEAN.
Member Since: September 9, 2008 Posts: 6 Comments: 3414
571. hurristat
3:38 PM GMT on November 02, 2008
Quoting hurricanemaniac123:
Trivia:

What atlantic hurricane season had the least named storms after 1983?


1986; 1992 if you don't count the subtropical storm, because that didn't have a name.
Member Since: October 15, 2008 Posts: 11 Comments: 2312
570. hurristat
3:36 PM GMT on November 02, 2008
Finished with the crazy track blog... warning it's long... but a lot of crazy tracks and my justification for giving them the score I did.

Link
Member Since: October 15, 2008 Posts: 11 Comments: 2312
569. hurricanemaniac123
3:36 PM GMT on November 02, 2008
Trivia:

What atlantic hurricane season had the least named storms after 1983?
Member Since: September 21, 2008 Posts: 9 Comments: 688
568. SSideBrac
3:32 PM GMT on November 02, 2008
Link apparently did not work - sorry
Member Since: September 21, 2008 Posts: 0 Comments: 265
567. SSideBrac
3:30 PM GMT on November 02, 2008
Some previous mention of the 32 Storm and the affect on the Brac - see below a link to an article on that storm.

Cayman Brac Museum has a poignant memorial to the tragic event including those Brackers lost at sea in Schooners - what is most telling is the repetition of family names and the proportion of the community actually lost in this Storm. Hope the link actaully works???

href="http://www.nationaltrust.org.ky/info/ringofstones.html" target="_blank">Link
Member Since: September 21, 2008 Posts: 0 Comments: 265

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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.