Thoughts on 2006 From June to Present

[Jeff Miller]

Any thoughts on 2006's season up to now?

NOTE: No hurricanes in either the Atlantic OR the Pacific at this time. There is Invest 96L in the Atlantic, but thats really all we have to talk about.

The question then is, what has caused this year to be so much quieter than last year? Or, flipping the coin, what abnormal pattern was in place last year that differentiated 2005 from most other seasons?

 

[Jim Leonard]

One big negative thiis season was the unexpected EL-Nino that developed during the late June early July timeframe. Another problem is the Saharan airmass which dominated the deep atlantic tropics throught the summer and is still in place currently which is highly unusual. If you look at the satellite imagery lately you will see the atlantic and Caribbean has a lack of cloud cover compared to other years. One other signal I can see is the (MJO) which is called the madden Julian oscillation, this feature is upward motion of the airmass over the tropical regions which comes around about every 45 days on the average. This season the atlantic basin has been stuck on the negative mode which is downward motion. With all the negatives we see this season in place I wouldn't be surprised to see little or no activity in October except some hybrid storm forming around the area near Bermuda.

 

[Pat Lawrence]

Something Dr. Avila from NHC wrote in an advisory last year:

"WILMA IS EXPECTED TO BECOME AN INTENSE HURRICANE IN THE NORTHWESTERN CARIBEAN SEA...TYPICAL OF THOSE HURRICANES WHICH COMMONLY OCCURRED IN OCTOBER DURING THE 30'S 40'S AND 50'S. THIS IS NOTHING NEW."

Would be interesting to know if anything has changed between now and the time frame he mentioned.

Cool subject matter, Jeffrey! Thanks!

Pat

 

[Tim Vasquez]

It's always great to see Jim Leonard here... I flinch when I see him listed as "Junior Member", but that's just based on the number of posts.

I'm not really sure if William Gray is considered a John Hope or Iben Browning of hurricane forecasting, but it's interesting that this season is lagging pretty well behind his expectations.
http://typhoon.atmos.colostate.edu/forecasts/2006/sep2006/

Tim

 

[Pat Lawrence]

I don't think this season is living up to any person's predictions/expectations. That's why I would be interested in any noted similarities between the present decade and the decades Avila mentioned. Chances are there were lulls in that time frame as well.

I was kinda hoping Jim Leonard would chime in regarding my comments as he has likely studied past tropical seasons in great depth. Maybe just change the thing under a person's name to member for everybody

One the things that makes stormtrack fun is being able to make a comment and in turn actually getting a response from some of the most brilliant people in that area of interest.

Pat

It's always great to see Jim Leonard here... I flinch when I see him listed as "Junior Member", but that's just based on the number of posts.

I'm not really sure if William Gray is considered a John Hope or Iben Browning of hurricane forecasting, but it's interesting that this season is lagging behind their expectations.
http://typhoon.atmos.colostate.edu/forecasts/2006/sep2006/

Tim

 

[Jim Leonard]

Pat you are correct, there were dud hurricane seasons during the 30's 40's and 50's. Seasons like 1930 with only 2 storms, 1935 with 6 storms, 1939, 5 storms, 1941, 6 storms, 1946, 6 storms, 1956, 8 storms, and 1960, 7 storms. These were examples of below average number and below average intensity during the previous active cycle. During the 1970's and 1980's dud seasons were the norm. If you go into the reason for the below average seasons during the 1930's to the 1950's you will notice they were most if not all El-Nino years.

 

[Simon Brewer]

Bear with me, but I remember doing research/learned a piece of data regarding El Nino years and Florida; until 2004 Florida was hit by 1 to 0 hurricanes during a weak El Nino. 2004 was of course the exception and off the top of my head I can’t remember the limits of the data. This piece of info basically translates to a below normal Atlantic Hurricane Season during an El Nino.

Sorry, I could muster up some effort and get a link to some hard data, but I lack the enthusiasm just like the current 2006 Atlantic Hurricane Season.

 

[Bart_Comstock]

Bear with me, but I remember doing research/learned a piece of data regarding El Nino years and Florida; until 2004 Florida was hit by 1 to 0 hurricanes during a weak El Nino. 2004 was of course the exception and off the top of my head I can’t remember the limits of the data. This piece of info basically translates to a below normal Atlantic Hurricane Season during an El Nino.

Sorry, I could muster up some effort and get a link to some hard data, but I lack the enthusiasm just like the current 2006 Atlantic Hurricane Season.

I found a simular article to what you are talking about, discusing the impacts of an el nino or la nina year on the number of hurricanes and possibility of landfalling ones.

"... Gray (1984a) has also shown a three-to-one ratio in continental U.S. landfalling intense hurricanes, with 0.74 per year striking during non-El Niño years and only 0.25 per year during El Niño events. Recently, Bove et al. (1998) ana lyzed all continental U.S. landfalling hurricanes and intense hurricanes of this century by the concurrent phase of ENSO. They found that the probability of at least two hurricanes striking the U.S. is 28% during El Niño years compared with 48% du ring neutral years and 66% during La Niña years. Likewise, the probabilities for at least one intense hurricane striking are 23%, 58% and 63% for El Niño, neutral and La Niña years, respectively."

here is a link to the article -> http://www.aoml.noaa.gov/hrd/Landsea/lanina/

 

[Pat Lawrence]

Pat you are correct, there were dud hurricane seasons during the 30's 40's and 50's. Seasons like 1930 with only 2 storms, 1935 with 6 storms, 1939, 5 storms, 1941, 6 storms, 1946, 6 storms, 1956, 8 storms, and 1960, 7 storms. These were examples of below average number and below average intensity during the previous active cycle. During the 1970's and 1980's dud seasons were the norm. If you go into the reason for the below average seasons during the 1930's to the 1950's you will notice they were most if not all El-Nino years.

Thanks for the response, Mr. Leonard! I’ll go back into the history, as best I can, and look at the seasons you mention (one of my favorite things is looking into what happened before).

One thing that really interested me concerning last season was the nearly constant bombardment in the press that suggested global warming is the cause for all of these tropical cyclone impacts. While this makes for good newspaper reading, have any of the people that study the tropics ever claimed the 2005 season was anything extraordinary? Seems to me the ones that really study the tropics are in agreement that all of it had happened before.

Anyway, Mr. Leonard, I look forward to studying the “downâ€￾ years you mentioned. Next year may be as active as 2005…..is that anything novel?...Or is it just our oceans and sun doing what they do best; that is, their respective contributions to planetary stability in temperature distribution?

Thanks for pointing me towards the years of interest!

Pat

 

[Jim Leonard]

One thing the global warming media clowns neglect to point out or don't do enough research before they make their claims is worldwide the number of tropical cyclones over the past 10 years or so is pretty much the same or slighly less than the previous decade. While the atlantic basin is way up since 1995 the eastern and western pacific has been much below average. Even this year while the atlantic is much slower than the last three seasons the western pacific is way below average in number and intensity. Normally the west pacific is up to at least storm number 23 or 24, so far they are on number 18W.
2005 atlantic season is one for the record books that will probably stand for more than 100 years for both number of tropical storms, hurricanes and cat-5's.

 

[Pat Lawrence]

One thing the global warming media clowns neglect to point out or don't do enough research before they make their claims is worldwide the number of tropical cyclones over the past 10 years or so is pretty much the same or slighly less than the previous decade. While the atlantic basin is way up since 1995 the eastern and western pacific has been much below average. Even this year while the atlantic is much slower than the last three seasons the western pacific is way below average in number and intensity. Normally the west pacific is up to at least storm number 23 or 24, so far they are on number 18W.
2005 atlantic season is one for the record books that will probably stand for more than 100 years for both number of tropical storms, hurricanes and cat-5's.

It would still be interesting to know how many storms were missed before all of this remote sensing/measurement showed up. I would think there was at least a year or two in the 30's, 40's, and 50's that came close to the 2005 numbers.

This isn't meant to sound argumentative at all as 2005 was a very active year. I just wonder if other years form the last 100 years or so might be comparable. I don't suppose an answer to that will ever be known with any degree of certainty - the technology just wasn't available. While the record contains some of the storms, does it contain them all from the old days?

I suppose we could start with 1960 and go from there

Pat

 

[Pat Lawrence]

intensity was not well observed for storms out in the open waters, thus no. of major and ACE might be higher in historic records if today's observation platforms were available)

Exactly! Tropical cyclones are fairly compact features most of the time (most of our recent majors (not just last year) haven't covered a very large area even with ts winds).

There could have been cat 5s, down to and including TSs, that developed that a ship, fortunately, never passed close to in the old days - thus, nobody can give 100% accurate numbers from that time frame.

Anyway, 2005 was great for those who enjoy the tropics.. that's probably the most important thing to keep in mind

Pat

 

[Ed Schoenborn]

Another way to compare 2005 data to early years is to do statistics for 2005 based on the technology we had in early years deleting the 2005 storms that we would not have detected in early early years. Ed

 

[Pat Lawrence]

Another way to compare 2005 data to early years is to do statistics for 2005 based on the technology we had in early years deleting the 2005 storms that we would not have detected in early early years. Ed

Which tropical cyclones from 2005 wouldn't have been detected in the old days? Probably some, but maybe all of them would have been?? That's what makes comparisons between now and then hard no matter how one decides to look at it, IMO.

Pat

 

[Jim Leonard]

One thing over the atlantic basin during the early years is there was a high density of ships at sea. Back then before satellites many of these ships would cross into the paths of tropical cyclones. Nowadays you rarely hear of any ship encountering a storm. The tracks of tropical cyclones dating back to the 1800's and before is from data from ships at sea.

 

[cdcollura]

Good day,

The Atlantic hurricane season, in my opinion, is pretty much over.

Ofcourse, since I said this, there would be a category-5 hurricane next week in the Gulf!

Anyway, what is going on is there is a substantial amount of upper-level wind shear that has supressed hurricane development this year. Also, if a storm did get going, it recurved (went from a westerly motion towards the US, then turned north, then NE staying out at sea). The presence of upper-level lows and troughs caused this, which is indicators of an El Nino.

El Nino causes the subtropical branch of the jet stream, including air over the northern tropics, to be stronger and / or posess a stronger westerly wind component (causing shear and / or storm recurverature).

Also, an El Nino causes drier conditions in Africa, so the SAL (Saharan Air Layer) became a drying issue to developing tropical systems this year. The trade wind inversion, caused by subsidence aloft, also was an issue this year.

The remaining threat, which is what needs to be watched during October, or even into November, is development over the SE Gulf or NW Caribbean. If a storm forms there, it most likely will recurve and move NE towards the US / Florida. The Gulf of Mexico has not been "tapped" yet for heat content either. I still feel that if a storm forms in that region, there will be shear to disrupt it, so a storm like Wilma last year is unlikely, but not impossible.

Such storms would not devleop from tropical waves, but remnant vorticity associated with stalled frontal zones in the NW Caribbean / SE Gulf.

Now you are wondering about the NAO (North Atlantic Oscillation), the cyclic shift of the NA current in negativce cycle, beginning in 1995 which caused an upswing in hurricanes. Yes, it is still there, but other things are counteracting it (like El Nino). Remember in 1997 there was not many storms, because of El Nino, and 1995 there were 21 storms, both with a -NAO.

El Nino this year started to develop by July. Looking at the OTIS (US Navy Oceanography Fleet page FNMOC), the SST Anomaly already shows 2-3 degrees higher than normal off South America in the Pacific near the Equator, extending out into the ocean westward. A La Nina appears below normal, and is the opposite. El Nino becomes strongest around late December (Christmas), hence the spanish name for "Boy Child" or "Christ".