Friday, May 6, 2016

My Final and Official 2016 Atlantic Hurricane Outlook.


The preliminary 2016 hurricane outlooks can be found at these links.
My first thoughts. 

2nd preliminary

This outlook was derived from determining all the likely scenarios, that I could envision.  I looked at past analog years, and did a percentage of probability, to try and determine what 2016 most likely will see.     

Everything within this outlook is a result of my analysis, and I'm solely responsible for the content. This outlook will explain not only what the number of tropical cyclones will be, but I will also show data and try to come up with what impacts there could be with land falling systems.  

The official Atlantic hurricane season runs from June 1  to November 30

SOI:

SOI values for 06 May 2016

Average for last 30 days         -16.72

Average for last 90 days         -14.75

Daily contribution to SOI calculation  10.36


The SOI is  into the positive side of the scale. It will most likely go negative again, before it goes positive again mid May.

Oceanic Nino Index (ONI):

 


Nino 3.4 forecast:

 


Analog Years:

1958, 1973, 1988, 1995, 1998, 2007, and 2010, The closest match to this year, seems to be 1958 and 1998.   

1983 was a transition year, but I didn't use it, because of the eruption of the El Chichon Volcano that year.  1982 was a Super El Nino that transitioned into a La Nina in the Summer of 1983. The 1983 hurricane season saw only four tropical cyclones. Because  the Volcano disrupted the 1983 pattern, I threw it out. 

Teleconnections:

First of all this is a El Nino to La Nina transition year. Transition years normally see more in the way of an active hurricane season.

The Atlantic Mutidecadal  Oscillation (AMO), has been generally positive for the last 10 years or so. The AMO is looking like it's in the process of doing a reversal. You can see how warm the  tropical Atlantic basin and off the East Coast of the United States are.  In fact the SST's in the Gulf of Mexico and Western Atlantic are warmer than most of analog years.

The  North Atlantic Oscillation (NAO) was positive for a lot of last winter, but now the NAO is more negative. In the spring this is an indication that the Azores High Pressure will be suppressed. This should allow for weaker easterlies; which in turn would allow for less Saharan Air Layer (SAL) dust in the tropical cyclone development zone. Instead there would be more moisture available for tropical development. With the Azores high pressure looking to be somewhat suppressed, it should help us see higher  Accumulated Cyclone Energy (ACE), which would increased the odds for more and possibility stronger tropical cyclones. 

In spite of the fact that the 2015 Atlantic Hurricane Season was an El Nino year with overall hostile conditions. We saw quite a few tropical waves. These helped to keep enough moisture in the Atlantic Prime Development Zone; that we saw tropical cyclones like Fred, Grace, and Ida.  

 If the high latitude blocking continues, the Atlantic SSTs could get a lot warmer.

Accumulated Cyclone Energy (ACE):

Total ACE looks to be 110-145 for the 2016 Atlantic Hurricane Season. Also at least half of the ACE points look to be in the Gulf of Mexico and western Atlantic Basin.

 

The warm Atlantic and tides:

The Main Development Zone in the Atlantic heated up rapidly in April, along with the Gulf Stream slowing down for two weeks. Tides along the Southeast Coast have been running a half foot to a foot above average since mid April. The same area has seen wind changes, caused by the an atmospheric bridge formed because of the El Nino in the Pacific; This in turn has heated the north Atlantic.
 
 
 

One reason for the quick warm up in the tropical Atlantic, is due to areas of low pressure forming along the subtropical jet atmospheric bridge; this has weaken the trade winds in the Atlantic.

 

 

An atmospheric bridge of strong winds is carrying heat and water vapor from the tropical Pacific to the tropical Atlantic. In the image above, you can see winds at the 250mb level, along with water vapor levels over the western hemisphere on 3 May, 2016. There is a large area of convection caused by warm air south of Mexico. All of this has injected heat and water vapor into the atmosphere.  

 
The second reason is the fading El Nino  intensified the rising motion of air over the northeastern Pacific Which increased substance over the tropical Atlantic.

More uplift than normal (green) has been caused by warm El Niño waters in the north eastern tropical Pacific. The tropical Atlantic south of the equator has had more subsidence than normal (brown). There has been above average  uplift induced by El Niño. This has shifted surface pressure patterns, caused a southwesterly wind anomaly in the tropical north Atlantic.


Both the  weaken trade wind flow and increased substance, is the reason for the rapid warming last month. This southerly flow caused cooling  along the equator in the Atlantic and warming north of the equator. 

 Many have been talking about the area of cold SSTs (cold blob) south of Greenland. There felt that this would actually cool the tropical Pacific. But because the 2015 El Nino lasted into the Spring of 2016, the southerly flow allowed for very strong high pressure around Greenland, which considerably warmed the SST in the area that was the cold blob. The CFSv2 has seen the demise of the cold blob.   
 

These same processes happened during the intense hurricane seasons of 1998, 2005, and 2010.  

This is all very important to understand, The Gulf Stream is mostly wind driven. When the trades weaken the Gulf Stream slows down. All of this leads to increased tides in the Caribbean, GOM, and along the East Coast from Florida to New England.
 

Preliminary water levels from Fort Worth pier, Florida, near where NOAA observes Gulf Stream flow. Note the jump in water levels to up to 1 foot above normal occurred at the same time as the Gulf Stream slowed.
The Gulf Stream typically flows in the low to mid 30 Sverdrups. It slowed to 19.8 on April 18, 2016. The last time a day had so little flow followed hurricane Sandy's disruption of the Florida current in late 2012.
Back in 2005 we saw the Atlantic heat up like it is in 2016.  One thing that is different is how much warmer the SSTs off the East Coast are this year compared to 2005. Another thing that is different is the tides along the East Coast are higher this year, then they were at the same time back in 2005.  

You may say, "OK so what!". The Atlantic cycle is such, that ocean surface heights are at their highest in Fall, and the lowest in the Spring. This means we can expect surface heights to increase for the next six months......in other words.....the tides will keep getting higher into fall of 2016. 

Putting it all together:

The El Nino has weakened a great deal, and the change to La Nina is very apparent. 

During this La Nina event, vertical wind Shear is going to be below average this hurricane season.

The last several years have seen more in the way of recurving tropical cyclones.  But with the SSTs in the Atlantic showing a definite shift toward a negative AMO, being quite warm. The African easterly jet, will be slower, giving time for systems to get their act together as they work west. With over half of the ACE points in the GOM, Caribbean, and western Atlantic, there will be increased risk for Gulf Coast and East Coast land falling tropical systems. 

Factoring all of this in, the 2016 Atlantic season will be quite interesting. The conditions in  Atlantic are prime for much above average tropical cyclone activity this year.  

We've already seen one hurricane in 2016. Hurricane Alex formed in the Atlantic January 13-17, 2016.

Based on what I've outlined, this is my call for the 2016 hurricane season.

13-18 named storms (This includes Alex)

8-10 hurricanes

3-5 major hurricanes

3-5 land falling tropical cyclones, at least one will be a major hurricane.

Impacts: 

Massachusetts Institute of Technology Professor Kerry Emanuel, is one of the leading authorities on atmospheric convection and the processes that intensify hurricanes. He has written books, papers, and made presentations on the physics of hurricanes. Even though he sits on the other side of global warming debate from my side.... I still have a lot of admiration and regard for him.  Professor Emanuel has written on how water temperature and hurricane activity has a direct correlation.

The SSTs in the tropical Atlantic MDZ is cooler than it was in 2010, but about the same as they were in 2005.  The strongest hurricanes need warm water under the surface.  The heat content of the Atlantic  is quite high.  Also the SST's off the East Coast are very warm.

Even though the Gulf Stream has returned to normal near Florida, tides along the East Coast remain high.  As the Pacific El Nino fades, and the tropical Atlantic warms weakening the trades. I expect to see more occurrences of the Gulf Stream slowing.
The 2016 Atlantic Basin Hurricane Season has me worried. The combination of warm SST in the GOM, Caribbean, off the East Coast, as well as in the MDZ in the Atlantic...speaks of the possibility of intense hurricanes (like the hurricanes of 1954).  With the high water in the Atlantic; I feel the risk of particularly destructive storms, making landfall on the East Coast or Gulf Coast is high. 

Everyone who lives on the East Coast and Gulf Coast, should review their hurricane plans, have their hurricane emergency kits ready, and pay attention to what the National Hurricane Center has to say.

That's it, thank you for taking the time to read. I would love to hear from you, either on here or on my Facebook pages.