November Atlantic hurricane outlook

By: Dr. Jeff Masters , 2:35 PM GMT on November 01, 2011

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Hurricane Rina is gone, and the tropical Atlantic is quiet, with no threat areas to discuss, and no models predicting development of a tropical depression during the coming seven days. So, are we all done for 2011? Or will this seventh-busiest hurricane season of all-time spawn a Tropical Storm Sean? Let's try and come up some answers. Since the active hurricane period we are in began in 1995, ten of the sixteen years (62%) have seen one or more Atlantic named storms form after November 1, for a total of fifteen late-season storms:

2009: Hurricane Ida on November 4
2008: Hurricane Paloma on November 6
2007: Tropical Storm Olga on December 11
2005: the "Greek" storms Gamma, Delta, Epsilon, and Zeta
2004: Tropical Storm Otto on November 29
2003: Odette and Peter in December
2001: Hurricane Noel on November 5 and Hurricane Olga on November 24
1999: Hurricane Lenny on November 14
1998: Hurricane Nicole on November 24
1996: Hurricane Marco on November 19

Only three of these storms (20%) caused loss of life: Hurricane Ida of 2009, which killed one boater on the Mississippi River; Tropical Storm Odette of 2007, whose floods killed eight people in the Dominican Republic; and Hurricane Lenny of 1999, which killed fifteen people in the Lesser Antilles. "Wrong-way Lenny" was both the deadliest and the strongest November hurricane on record (Category 4, 155 mph winds). There have been only seven major Category 3 or stronger hurricanes in the Atlantic after November 1. Part of the reason for the relatively low loss of life for November storms is that they tend to form from extratropical low pressure systems that get cut off from the jet stream and linger over the warm waters of the subtropical Atlantic. These type of systems typically get their start in the middle Atlantic, far from land, and end up recurving northeastwards out to sea. However, as I noted in the wake of last year's Hurricane Tomas last November in my blog post, Deadly late-season Atlantic hurricanes growing more frequent, It used to be that late-season hurricanes were a relative rarity--in the 140-year period from 1851 - 1990, only 30 hurricanes existed in the Atlantic on or after November 1, an average of one late-season hurricane every five years. Only four major Category 3 or stronger late-season hurricanes occurred in those 140 years, and only three Caribbean hurricanes. But in the past twenty years, late-season hurricanes have become 3.5 times more frequent--there have been fifteen late-season hurricanes, and five of those occurred in the Caribbean. Three of these were major hurricanes, and were the three strongest late-season hurricanes on record. Dr. Jim Kossin of the University of Wisconsin published a 2008 paper in Geophysical Research Letters titled, "Is the North Atlantic hurricane season getting longer?" He concluded that yes, there is an "apparent tendency toward more common early- and late-season storms that correlates with warming Sea Surface Temperature but the uncertainty in these relationships is high". The recent increase in powerful and deadly November hurricanes would seem to support this conclusion.


Figure 1. The strongest hurricane on record in the Atlantic in November, Hurricane Lenny, takes aim at the Lesser Antilles on November 17, 1999. Image credit: NOAA.

Forecast for November 2011
The oceans are certainly warm enough to support continued development of tropical cyclones. Sea Surface Temperatures (SSTs) over a wide area of the tropical Atlantic are 0.5 - 1.0°C above average, and are well above the 26°C (79°F) threshold typically needed to support tropical storm formation (Figure 2.) However, wind shear is starting to rise over much of the tropical Atlantic as the jet stream moves farther south in its usual seasonal cycle. Wind shear over most of the Atlantic will be too high to support tropical storm formation over the coming two weeks, according to the latest run of the GFS model (Figure 3.) Only the southern Caribbean and a few transient pockets in the middle Atlantic east and southeast of Bermuda will have low enough wind shear to support tropical storm formation over the next two weeks. The African Monsoon is quiet this time of year, and we no longer have African waves coming off the coast of Africa that can act as the seeds for formation of a tropical storm in the Caribbean. If we do get a tropical storm, it will probably be to the northeast of the Lesser Antilles, far from land, in a region where an extratropical low pressure system gets cut off from the jet stream and lingers long enough over warm waters to acquire tropical characteristics and get a name. Both the GFS and ECMWF models are suggesting a system like this may take form 7 - 10 days from now. Taking all these factors into account, I predict we are all done this hurricane season with storms that will cause loss of life, but there is still a 70% chance that we will get one or more named storms in the middle Atlantic that will stay out to sea and not affect land.


Figure 2. Sea surface temperatures in the Atlantic on November 1, 2011. The black dotted line is the 26°C (79°F) isotherm, which marks the boundary where tropical storm formation can typically occur. A large portion of the Atlantic is still capable of supporting tropical storm formation.


Figure 3. Wind shear forecast for November 11, 2011, as predicted by the 2am EDT November 1, 2011 run of the GFS model. The model is predicting low wind shear of less than 4 m/s (about 8 knots, light red colors) in the southern Caribbean and southern Lesser Antilles Islands. Very high wind shear in excess of 44 m/s (85 knots, orange colors), associated with the jet stream, will protect regions north of the Caribbean.

I'll have a new post Wednesday or Thursday.

Jeff Masters

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Quoting bohonkweatherman:
Harrisburg is only 56.97 ahead of me. :) I hate this Texas drought, there has been NO improvement where I live.



I'd love to know what the total rainfall over the USA has been this year. Maybe it's been close to normal with all the dry and wet places. cancelling each other out.
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Quoting BaltimoreBrian:
Harrisburg PA set their annual precipitation record in September!


The old record was 59.27" in 1972, and 65.97" now. Harrisburg PA records began in 1888.

Harrisburg PA has never had 5 feet of precipitation in a year before in our records. And I bet by the end of the year they will have passed 6 feet.
Hey!.
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Regardless if Rina was our last storm or not, this will be the first time in recorded history that two seasons in a row featured more 15 named storms that I can find. Could be wrong, but its a first.

2010 had 19.
2011 has had 17.

Way the ENSO pattern is shaping up, 2012 will probably be fairly active too. But the trend seems to be downward and more destructive with the whole 2-3 year La Nina year. So, based on that alone and nothing else, 15 named next year seems a good bet. I have no basis for that besides a gut feeling however.
Member Since: July 8, 2005 Posts: 259 Comments: 23627
Quoting CybrTeddy:
According to the models, it is very possible a hybrid/subtropical system could form north of Hispaniola next week by the 9th. This would be similar to Olga in 2007. There has never been a season to end with 17 named, so I think we'll tie 1969 with activity.

I agree.
Member Since: July 6, 2010 Posts: 113 Comments: 31554
According to the models, it is very possible a hybrid/subtropical system could form north of Hispaniola next week by the 9th. This would be similar to Olga in 2007. There has never been a season to end with 17 named, so I think we'll tie 1969 with activity.
Member Since: July 8, 2005 Posts: 259 Comments: 23627
sar2401, check this out:

http://trmm.gsfc.nasa.gov/
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Quoting HurricaneHunterJoe:


Hurricane Hunter, what do those pictures show? I really hate it when people seem to post random grpahics with no explanation at to what they are or what they mean.
Member Since: October 2, 2004 Posts: 0 Comments: 13389
In addition to rain and snow records being broken already, my neighbor noted that the woolly caterpillars had an exceptionally thick coat this fall. This is in keeping with Dr. Master's observation a few days back.
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If you live north of a line from Boston to Chicago to Great Falls to Seattle you might have a chance at viewing the aurora tonight. Things have been picking up, up there.
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Quoting BaltimoreBrian:
Harrisburg PA has had almost double their normal rainfall this year.

Jeez that formatted badly. Formatting less ugly now. But not great.

...THE HARRISBURG PA CLIMATE SUMMARY FOR NOVEMBER 1 2011...
VALID TODAY AS OF 0500 PM LOCAL TIME.



PRECIPITATION (IN)
TODAY 0.00

SINCE JAN 1 65.97

34.38 is the normal.
31.59 above normal
35.04 last year.
Harrisburg is only 56.97 ahead of me. :) I hate this Texas drought, there has been NO improvement where I live.
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Quoting Neapolitan:

I'm sure it's all coincidence. Coincidence and nothing more... ;-)

Of course, a starting point is to determine how this year compares in that regard to other years.
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Harrisburg PA set their annual precipitation record in September!


The old record was 59.27" in 1972, and 65.97" now. Harrisburg PA records began in 1888.

Harrisburg PA has never had 5 feet of precipitation in a year before in our records. And I bet by the end of the year they will have passed 6 feet.
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Quoting BaltimoreBrian:


It's amazing that so many cities with long weather records are breaking their annual precipitation records in October!

I'm sure it's all coincidence. Coincidence and nothing more... ;-)
Member Since: November 8, 2009 Posts: 4 Comments: 13470
LOL You guys are arguing about recording storms before satellites and the doc's use of "all time"! Dang, you guys NEED activity.
Member Since: August 28, 2008 Posts: 79 Comments: 3486
Harrisburg PA has had almost double their normal rainfall this year.

Jeez that formatted badly. Formatting less ugly now. But not great.

...THE HARRISBURG PA CLIMATE SUMMARY FOR NOVEMBER 1 2011...
VALID TODAY AS OF 0500 PM LOCAL TIME.



PRECIPITATION (IN)
TODAY 0.00

SINCE JAN 1 65.97

34.38 is the normal.
31.59 above normal
35.04 last year.
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Quoting HurricaneHunterJoe:


Rina Thunderstorm tops to almost 11 miles high






GETN pretty high!
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Quoting Neapolitan:

Cleveland, too


It's amazing that so many cities with long weather records are breaking their annual precipitation records in October!

Williamsport PA broke their annual precipitation record on October 17. Their records go back to 1895.

The recent noreaster boosted Williamsport's precipitation total to 63.18". The old record was 61.27" in 1972. 70" for Williamsport is a good possibility this year.
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Rina Thunderstorm tops to almost 11 miles high
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Quoting TampaSpin:
Blast from the past; first hurricane hit Pilgrims in 1635


That's a cool find Tampa Spin. Check out this link where Chris Landsea talks about that storm. A very good graphic on page 10.

The paper covers several other northeastern hurricanes and some in the south Atlantic and Gulf as awe..

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Good piece of historic reading...
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*This post is here for no apparent reason*
Member Since: July 6, 2010 Posts: 113 Comments: 31554
This article about hurricane frequency over the past 5,000 years in the Caribbean is doubtless interesting. At $32 it will doubtless remain unread by me. Unless of course Dr. Masters decides to post it ;)
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Same deal for New Jersey. Probable major hurricane in New Jersey in the 14th century.

Probably another major hurricane landfall in New Jersey in the 500s-600s.
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Paleotempestology in South Carolina.

Unfortunately the full article is available for payment only.
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I have begun my final entry in my Weather and Warfare series. The Spanish Armada of 1588. The background entry is here. Hope you find it interesting.
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Quoting Articuno:

Your not too far away from me.
BTW since it's so cool out, I am going to go "photo hunting" (AKA photography)


Not too far away at all. I was in Pasadena Sunday watching the Ravens game at Glory days.
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There is a significant amount of work we can do now, with old data that we couldn't or didn't do before.
For example, we can estimate evapotranspiration based on daily temperature ranges. This allows us to look at old simple data in a new way without modern or advanced equipment.
Sometimes you can look into past data with fresh eyes.
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This is from Crown Weather:

Rob Lightbown on October 31, 2011, 5:08 am

The tropical Atlantic is quiet this morning with no areas of concern this morning. It is expected to remain this way throughout this week and likely into this upcoming weekend.

Once we get into next week, we may be keeping a close eye on a low pressure system that is forecast to first track off of the North Carolina coast this weekend and then potential retrograde westward towards the southeastern Bahamas by Tuesday and Wednesday of next week. The European model is by far the strongest with this forecast representation of the low pressure system while the GFS model is much more muted with this system. It should be pointed out that the Canadian model also forecasts a low pressure system starting to retrograde by early next week. The upper level forecast maps of the European model show that a piece of a eastward progressing trough is to break off next week and retrograde westward. Should this happen, it would likely be non-tropical in nature at first, however, it would have the chance of becoming more tropical in nature as it tracks westward towards the Bahamas.

Should this storm form, it would likely bring several days of strong easterly onshore winds and very rough surf from coastal North and South Carolina southward through the beaches of the Florida Peninsula starting later this weekend and continuing through much of next week.

So, this will be something that we will be keeping an eye on and will keep you all updated.

Member Since: April 24, 2011 Posts: 1 Comments: 601
Quoting TropicalAnalystwx13:

It doesn't matter, because we can't go back in time with the technology we have now and see.
But, it does matter if you're trying to compare this year to previous years, which was a large part of Dr. Masters' post.
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Quoting usa777:


Same here in Annapolis. A good start to the month.

Your not too far away from me.
BTW since it's so cool out, I am going to go "photo hunting" (AKA photography)
Member Since: October 22, 2011 Posts: 0 Comments: 2302
Quoting Articuno:

Sky blue skies here in Pasadena.


Same here in Annapolis. A good start to the month.
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Quoting TropicalAnalystwx13:

It doesn't matter, because we can't go back in time with the technology we have now and see.
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Quoting TampaSpin:
Honestly before Satellites......HOW many storms went unnamed that was never KNOWN because of Location out at sea.....Lets be real.

Better yet how many of this years storms would not have been named before Satellites....is a better question??????

It doesn't matter, because we can't go back in time with the technology we have now and see.
Member Since: July 6, 2010 Posts: 113 Comments: 31554
Quoting Ameister12:
Well Cincinnati had it's wettest annual precipitation ever. Not surprising. It has been VERY rainy up here.

Cleveland, too
Member Since: November 8, 2009 Posts: 4 Comments: 13470
They name as many storms as possible these days to justify their existence and funding. PERIOD!!!!!!!!!!!
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Honestly before Satellites......HOW many storms went unnamed that was never KNOWN because of Location out at sea.....Lets be real.

Better yet how many of this years storms would not have been named before Satellites....is a better question??????
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Quoting Jax82:
7th busiest hurricane season of earths last 4 billion years, man thats crazy.
i'm sure the doc meant in recorded weather history
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My problem with the way Dr. Masters chose to write this blog is that his observations will end up being quoted in articles directed to the general public. They are not aware that "of all time" really means between 60 and 140 years, depending on your definition. Using a qualifier like "known history" is more scientifically precise. As a scientist, precision, within limits, should always be used. Imagine a medical doctor, for example, writing "This was the seventh highest year for deaths from heart attacks of all time.". That would clearly be a very imprecise way to report a statistic, and a meteorologist should certainly be as a clear as a medical doctor when reporting statistical data.

In terms of early or late season hurricanes, there's a high probability those numbers have jumped over the past fifty years due to being able to see on satellite what probably would have gone unseen and unreported when the storms occurred over the open ocean and never struck land. Assuming we see another tropical system this month, I suspect it will be one of those phantom hurricanes that occurred in the past but we never knew it happened.
Member Since: October 2, 2004 Posts: 0 Comments: 13389
Quoting RitaEvac:
Did anybody mention about the 6.3 quake off Mexico this morning at 7:32AM CDT....

I was going to say about it, but I wouldn't think anyone would care.
Member Since: October 22, 2011 Posts: 0 Comments: 2302
Quoting Dodabear:


Truck it on down to the Salvation Army, they can find a use for it.


I'm sure its gonna melt before its consumed because of GW!
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Did anybody mention about the 6.3 quake off Mexico this morning at 7:32AM CDT....
Member Since: July 14, 2008 Posts: 1 Comments: 9628
Quoting TampaSpin:
I just bought $50.00 in Candy yesterday....and have $45.00 in Candy left......Neighbors all have the same left too......It WAS THE SLOWEST HALLOWEEN EVER!

ikr
when i went trick or treating it felt like forever, and it felt like nobody else was going trick or treating
Member Since: October 22, 2011 Posts: 0 Comments: 2302
Quoting Neapolitan:

No assumptions; no games. Just the observed truth. Here are a couple of randomly-chosen examples, and I'm sure I could spend ten minutes and find another 50:

--A NEW ALL TIME RECORD HIGH TEMPERATURE OF 111 DEGREES WAS SET ON
SUNDAY JUNE 26 2011 AT AMARILLO. THIS EXCEEDED THE PREVIOUS ALL TIME
RECORD HIGH TEMPERATURE OF 109 DEGREES SET ON FRIDAY JUNE 24 2011..


--...NEW ALL TIME RECORD HIGH TEMPERATURE SET IN PUEBLO...
THE HIGH TEMPERATURE IN PUEBLO THIS AFTERNOON WAS 109 DEGREES.
THIS SETS A NEW ALL TIME RECORD HIGH FOR THE CITY OF PUEBLO...
BREAKING THE PREVIOUS RECORD OF 108 DEGREES...SET JUNE 29 1990.


The point being, it seems only the most simple-minded or politically-motivated would insist on seeing some variation of the qualifier "in recorded history" after each and every mention of a particular weather record lest they become confused as to whether that record applies equally to events that occurred in 2011 and, say, 10 million BCE. By the same token, when Dr. Masters talks about the "seventh-busiest hurricane season of all-time", I can't imagine any right-thinking person wondering whether he's comparing 2011's tropical cyclones to those that spun up in 1807 CE or 1066 CE or 45 BCE...


Truth is in the eyes of the beholder.

I am neither simple-minded nor politically motivated. Semantics and S.I. Hayakawa probably don't ring a bell with you, and, if they do, then you did not study well. And I'm guessing you never read J. Edgar Hoover's propaganda classic, Masters of Deceit. Or maybe you did and try to use it to your advantage.

No matter what you believe constitutes "right-thinking" (Not sure if by this hyphenated word you mean correct or politically conservative thinking, but it does not matter for either way it is a judgmental word.) any of the examples you use including Dr. M's statement in this blog are at least unclear if not incorrect when one considers history and proper use of English.

"What's your game?" has more than one meaning. You picked the one I thought you would. I'll leave you to figure out the one I meant.

I disagree with you about what "of all time" means and will leave it at that.

Have a nice day as they say in L.A.
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Quoting TampaSpin:
I just bought $50.00 in Candy yesterday....and have $45.00 in Candy left......Neighbors all have the same left too......It WAS THE SLOWEST HALLOWEEN EVER!


Truck it on down to the Salvation Army, they can find a use for it.
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Quoting BaltimoreBrian:
A beautiful day in Baltimore. Sunny and crisp. Near 60.

Sky blue skies here in Pasadena.
Member Since: October 22, 2011 Posts: 0 Comments: 2302
I just bought $50.00 in Candy yesterday....and have $45.00 in Candy left......Neighbors all have the same left too......It WAS THE SLOWEST HALLOWEEN EVER!
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49. PlazaRed


..excellent post.
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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.