A record quiet start to the 2010 Northern Hemisphere tropical cyclone season

By: Dr. Jeff Masters , 3:42 PM GMT on August 12, 2010

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The remnants of Tropical Depression Five have re-organized this morning, and the storm is pounding Southeast Louisiana with heavy rains. Radar imagery out of New Orleans shows that the remains of TD 5 have have formed some respectable low-level spiral bands that have brought heavy rains in excess of five inches in some areas. However, with the circulation center now moving over land, not much further development can occur.


Figure 1. Morning radar image of TD Five's remains.

Why so quiet in the Atlantic?
The Tropical Atlantic is quiet, and there are no threat areas to discuss today. The Invest 93 system we were tracking has been destroyed by dry air and wind shear. There are a couple of long-range threats suggested by some of the models--the GFS model predicts a tropical depression could form off the coast of Mississippi six days from now, and the NOGAPS model thinks something could get going in the Gulf of Mexico's Bay of Campeche seven days from now. Neither of these possibilities are worthy of concern at present. Overall, it's been a surprisingly quiet August, considering the pre-season predictions of a hyperactive season. According the National Hurricane Center, this hurricane season has been exactly average so far. There have been three named storms and one hurricane as of August 12. The average date of formation of the third named storm is August 13. One hurricane typically forms by August 10. One reason for this year's inactivity may be an unusual number of upper-level low pressure systems that have paraded across the tropical Atlantic. These lows, also called Tropical Upper Tropospheric Trough (TUTT) lows, tend to bring high wind shear that inhibits tropical cyclone formation. The other major factor appears to be that vertical instability has been unusually low in the Atlantic over the past month. Instability is measured as the difference in temperature between the surface and the top of the troposphere (the highest altitude that thunderstorm tops can penetrate to.) If the surface is very warm and the top of the troposphere is cold, an unstable atmosphere results, which helps to enhance thunderstorm updrafts and promote hurricane development. Since SSTs in the Atlantic are at record highs, enhancing instability, something else must be going on. Dry air can act to reduce instability, and it appears that an unusually dry atmosphere over the Atlantic this month is responsible for the lack of instability.


Figure 2. Vertical instability (in °C) over the Caribbean (left) and tropical Atlantic between the Lesser Antilles Islands and coast of Africa (right) in 2010. Normal instability is the black line, and this year's instability levels are in blue. The atmosphere became much more stable than normal in both regions at the end of July. This lack of instability also extends to the Gulf of Mexico and North Atlantic Ocean between Europe and North America, as well as the Western Pacific east of the Philippines, and the South Indian Ocean. Image credit: NOAA/CIRA.

A record quiet start to the 2010 tropical cyclone season in the Northern Hemisphere
What is really odd about this year, though, is the lack of tropical cyclone activity across the entire Northern Hemisphere. Usually, if one ocean basin is experiencing a quiet season, one of the other ocean basins is going bonkers. That is not the case this year. Over in the Eastern Pacific, there have been five named storms and two hurricanes. The average is seven named storms and four hurricanes for this point in the season. This year's quiet season is not too surprising, since there is a moderate La Niña event underway, and La Niña conditions usually supresses Eastern Pacific hurricane activity. But over in the Western Pacific, which usually generates more tropical cyclones than any ocean basin on Earth, it has been a near-record quiet season. Just four named storms have occurred in the West Pacific this year, and the average for this date is eleven. Only one typhoon season has had fewer named storms this late in the season--1998, with just three. The total number of named storms in the Northern Hemisphere thus far this year is fifteen, which is the fewest since reliable records began in 1948. Second place belongs to 1983 and 1957, with eighteen named storms. According to an email I received from NOAA hurricane researcher Gabe Vecchi, the lack of tropical cyclones so far this year in the Northern Hemisphere is between a 1-in-80 and 1-in-100 year event.

So, what is causing this quiet tropical cyclone season? One possibility is that since Northern Hemisphere land areas have heated up to record temperatures this summer, this has created strong rising motion over the continents. This rising motion must be compensated by strong sinking motion over the adjacent oceans in order to conserve mass. Sinking air causes drying and an increase in stability. Another possibility is that the unusual jet stream configuration that is responsible for the Russia heat wave and record flooding in Pakistan is also bringing dry, stable air to the Northern Hemisphere's tropical cyclone breeding grounds. It is also possible that climate change is causing the reduction in tropical cyclone activity, for a variety of complex reasons. Computer simulations of a future warmer climate generally show a reduction in global number of tropical cyclones (though the strongest storms get stronger), and it is possible we are seeing a preview of that future climate. Or, this year's quietness may simply be natural variability. It will be interesting to see when the Russian heat wave breaks if vertical instability over the Atlantic increases back to normal levels. Current forecasts from the GFS and ECMWF models project the Russian heat wave to break late next week.

Moscow's air remains clear; coolest temperatures in two weeks
Moscow's winds remained favorable for keeping smoke away from the city today, and temperatures "cooled" to at Moscow's Domodedovo airport to 33°C (91°F)--the lowest maximum temperature since a high of 32°C (90°F) was recorded on July 30. Moscow's airport has reached a maximum temperature of 30°C (86°F) or higher for 35 consecutive days now (at Moscow's official observing site, the Moscow Observatory, this string is 30 days.) Moscow's average high temperature for August 12 is 20°C (68°F). Moscow's high temperatures have averaged 15°C (27°F) above average so far this August--a truly extraordinary anomaly for a country so famous for its notorious cold weather. The latest forecast for Moscow calls for high temperatures of 30 - 33°C (86 - 91°F) Thursday through Monday. This is still 23°F above normal, but will be a welcome change from the extreme heat of the past two weeks. Long range forecasts from the ECMWF and GFS models continue to suggest that a series of troughs of low pressure will begin to attack the ridge of high pressure anchored over Russia beginning on Wednesday, bringing cooler temperatures just 5°C (8°F) above average to Russia late next week. By ten days from now, the ECMWF model shows a strong trough of low pressure over Moscow, and a end to the Great Russian Heat Wave of 2010.

Next update
I'll have an update Friday morning.

Jeff Masters

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South of Gulfport
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Thanks Doc. I needed that.
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I was wondering where all the model apocalyptocanes had gone...

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NEXRAD Radar
New Orleans, Storm Total Surface Rainfall Accumulation Range 124 NMI

Member Since: July 3, 2005 Posts: 426 Comments: 128648
Quoting ElConando:


The ever Illusive yet dreaded 200mph Hurricane.


It will stay elusive until we develop a 225mph anemometer
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noticing another COC offshore on visible now, can anybody else confirm
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Quoting StormW:
Do ya think that the stronger A/B high we've had in the past few weeks may be a contributor to the lack of instability?


High's usually bring stability to the atmosphere so it is a good possibility it contributed greatly to it.
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Here's the wave at 114 hours on the GFS, or Tuesday


Emerges off the coast late Tuesday, looks to be a pretty good looking invest at that point.
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Quoting OpusDei:


Just watched it, many thanks! Was just curious if you had any feelings of likelyhood. Seems some of the other models are picking up on some pressure drops in GOM around that time frame(100hrs). Wasn't sure if this might be them starting to hint at that potential, of if they were looking at a different system.


Ya there are some hints on the other models. With a potential trough-split occurring the area should definitely be monitored for homegrown mischief.
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Quoting StormW:


The faster trades don't allow heat to build up in the tropics, as well as slightly cooling the SST skin temperature...faster trades imply more evaporation, which won't allow the SST's to do their job at helping to increase instability.


Thanks, Storm...
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Quoting Patrap:
I see a wider overall now..

I was watching the convection Locally



it seems to have been an ongoing trait of this thing to out spin itself in an ever trending march westward.
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225. JRRP
Quoting CybrTeddy:
GFS sniffed out Bertha and Dean pretty good.

Bill
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Quoting Levi32:


Holy heck.
It already has spin to it and is quite sizeable now! Covers most of northern Africa!
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Quoting Floodman:


The smart ones have been saying this all along; that there is a possiblity that a warmer atmosphere would produce not only fewer hurricanes, but also increase the intensity of the ones that do form....these theories were based in some part on the supposition the Doc mentions in his blog that a warmer landmass would decrease uplift over the oceans, reducing the number of storms.

Given that the storms are a function of the atmosphere trying to regulate temperature, this could lead some rather incredible storms...


The ever Illusive yet dreaded 200mph Hurricane.
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I see a wider overall now..

I was watching the convection Locally



Member Since: July 3, 2005 Posts: 426 Comments: 128648
Its Raining Oil in Louisiana.

Sugarcane farmers shot a video of an oil well blowout in Assumption Parish that happened about 4:00am this morning. Apparently the well is blowing oil and natural gas. People have reported oil raining down as far away as 1-mile from the well blowout.

Link
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Quoting Patrap:
The CoC swirled right over da Lake..



Zoom out a bit and look again, Pat.
GFS sniffed out Bertha and Dean pretty good.
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WOW , things geting pretty interesting in the gulf again !!!!!!! I thought the season might be winding down :(
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Quoting Patrap:
The CoC swirled right over da Lake..


seems to be a decoupled spin from the main one still swirling offshore. little convection around that one... but i still pick up a closed loop from what's left.
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Quoting Enigma713:

Didn't the GFS sniff out Gustav or Ike a long way out too? (or was that the ECMWF?)


Not sure.
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Quoting StormW:
Do ya think that the stronger A/B high we've had in the past few weeks may be a contributor to the lack of instability?


Can you elaborate?
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Quoting StormW:
Do ya think that the stronger A/B high we've had in the past few weeks may be a contributor to the lack of instability?


That is likely.
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Member Since: July 3, 2005 Posts: 426 Comments: 128648
Quoting StormW:
Do ya think that the stronger A/B high we've had in the past few weeks may be a contributor to the lack of instability?

Does make sense at least i think so any.
Thanks
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The low also comes out pretty much on top of the Cape Verde islands.
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Quoting Drakoen:


This reminds me of when the GFS sniffed out Dean almost two weeks in advance.

Didn't the GFS sniff out Gustav or Ike a long way out too? (or was that the ECMWF?)
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The CoC swirled right over da Lake..


Member Since: July 3, 2005 Posts: 426 Comments: 128648
When's the 12z ECMWF come out?
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Thanks for the response pilot guy 1.

I do understand that the oceans are positively huge, but with oil being a hydrophobic molecule, I thought it possible that it could spread in a thin layer on the surface. A single drop of oil can coat the top of a kitchen sink.

There was even some silly talk (research papers?) a few years back about reducing evaporation in the MDR by spreading a sheen of oil over the surface. Dr. Masters dismissed that in particular (rightly I think), and geoengineering in general, as irresponsible given that we don't know the long term impacts of that.

The exchange of heat energy between land/ocean and the atmosphere via evaporation and condensation is a very critical component of earth's habitability due to the temperature regulation the interaction provides.

Anyway, I guess even though many things are lining up this season, it doesn't mean we're guaranteed a storm. Just because each dice has an extra 6 on it doesn't mean you're gonna roll boxcars every time!
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Here's the current Sea Surface Temperature map. Note that most of the non-land area in this image is capable of sustaining tropical cyclones; only those areas in blue and located outside the solid red line are too cool for TCs. Pay special attention to the expanding area of surface temperatures at or above 32°C (about 90°F) on Florida's west coast, in parts of the Bahamas, at the northern edge of Cuba, and stretched out in the western Atlantic between the 8th and 10th parallels.

Come and get it!Source

Note 1: From Dr. Jeff Masters: "When using the TCHP map, TCHP is not really a good measurement in water that is shallow (less than 50 meters or so). Because TCHP is a function of volume and depth of warm water, TCHP will never appear to be high around coastlines/ocean shelves that are shallow. Remember Charley of 2004 strengthened significantly just offshore of SW FL. [That is,] in a region of low TCHP."

Note 2: most of the Gulf generally sees its maximum SSTs in August, while the northern half of the Caribbean tops out in September. The southern Caribbean and parts of the eastern Atlantic max out in October. (Link)
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Quoting Levi32:


I did in my update. Nothing has changed. We should keep an eye out for that possibility. If it occurs the situation would be conducive for development.


Just watched it, many thanks! Was just curious if you had any feelings of likelyhood. Seems some of the other models are picking up on some pressure drops in GOM around that time frame(100hrs). Wasn't sure if this might be them starting to hint at that potential, of if they were looking at a different system.
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Afternoon all.

Ah. The Doc has put the finger on something we may not have been thinking about. I also like the sophisticated way he has incorporated all the posts about the Russian heat wave - which many dismissed as pandering to GW supporters - into his discussion of the 2010 ATL tropical season.... puts a lot of people in their places... and thereby made a very strong point about how an understanding of the macro-weather patterns is vital to understanding of micro patterns.

Someone was talking yesterday about how the Doc's lowered the standard of the blog by his posts.

???????

Good stuff, Doc. Appreciate it.
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@192:

Well said...the dynamics in here are pretty interesting sometimes
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Quoting clwstmchasr:



The good news is that it take it out to sea.

Unless you are on Bermuda.
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Quoting wayfaringstranger:
Ya know, after reading the blog and posts, I guess from a scientific standpoint I see the storms comming but if I post something like "hey this is a huge storm with lots of potential.." then you get branded pretty hard by some crazy remarks. Its kinda weird because there are so many dynamics on this blog i.e. you have folks who think of storms like eating brussell sprouts (down casters?) and I can understand why because who in their right mind wants a potential death maker to rip into our home land (wish casters?)?

But when scientifically there is evidence that from now through October(and plenty of it) that points to potentially tramatic times so now you may choose to then stick your fingers in your ear and say na na naha naha cant hear you! Or even react with negative posts on a blog! Or you can choose to be prepared and get well informed...

Can you really fault a guy for advising people to get the word out on hurricane prepardness? Does that now make me a prepared caster? Well if the shoe fits...



Well put!
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Thoughts on the wave near 10W, 15N? This one could be Danielle, but recurve out to sea, while the wave behind it could be Monster Earl, like the 12z GFS shows.
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Quoting OpusDei:


Levi,
GFS seems to be hinting at the idea you were toying with re GOM/remnant TD5 in about 100 hrs etc (some convection dropping into N.GOM). Can you comment on that?


I did in my update. Nothing has changed. We should keep an eye out for that possibility. If it occurs the situation would be conducive for development.
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The GFS hates Bermuda this week.
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Quoting StormW:
Great update, Levi!


Thanks Storm :)
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Ya know, after reading the blog and posts, I guess from a scientific standpoint I see the storms comming but if I post something like "hey this is a huge storm with lots of potential.." then you get branded pretty hard by some crazy remarks. Its kinda weird because there are so many dynamics on this blog i.e. you have folks who think of storms like eating brussell sprouts (down casters?) and I can understand why because who in their right mind wants a potential death maker to rip into our home land (wish casters?)?

But when scientifically there is evidence that from now through October(and plenty of it) that points to potentially tramatic times so now you may choose to then stick your fingers in your ear and say na na naha naha cant hear you! Or even react with negative posts on a blog! Or you can choose to be prepared and get well informed...

Can you really fault a guy for advising people to get the word out on hurricane prepardness? Does that now make me a prepared caster? Well if the shoe fits...

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Quoting clwstmchasr:



The good news is that it take it out to sea.


Let's take it easy....system is still way inland over Africa - the talk of exact position of landfall this far out seems nonsensical since models are really crap at forecasting upper level patterns 2 weeks out...!
But yeah, no doubt the system may be a problem..
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Quoting LAlurker:
I can answer that - there are no "i"s in monsta!


BOO!
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Quoting DestinJeff:


That would be a Light Crude note.

Actually a "light sweet crude" note.
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Quoting Levi32:


Something like 10 runs in a row on the GEFS now. The ensemble means have been pretty incredible for 2 weeks out.


Levi,
GFS seems to be hinting at the idea you were toying with re GOM/remnant TD5 in about 100 hrs etc (some convection dropping into N.GOM). Can you comment on that?
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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.