When will the multi-decade active era that began in 1995 end?

[xtyphooncyclonex]

It has ended

http://www.wunderground.com/blog/JeffMa ... rynum=2998

The forecasters cited the following main factors that will influence the coming season:

1) The current borderline weak/moderate El Niño event is expected to persist or intensify during the 2015 hurricane season. El Niño events tend to suppress Atlantic hurricane activity in three ways:

- By creating high levels of wind shear over the tropical Atlantic, which tends to tear storms apart.
- By increasing sinking motion and high pressure over the tropical Atlantic.
- By making the air more stable over the tropical Atlantic.

2) Near-average sea surface temperatures (SSTs) are in place over the hurricane Main Development Region (MDR), from the Caribbean to the coast of Africa between between 10°N and 20°N. These SSTs are expected to be near or below average during the peak August - October portion of hurricane season, and are expected to be cooler than SSTs in the remainder of the global tropics (SSTs in the remainder of the global tropics were 0.31°C warmer than SSTs in the MDR in May.) This configuration of SSTs is often quite hostile to Atlantic tropical cyclone development.

3) The active period of hurricane activity that began in 1995 due to a natural decades-long cycle in hurricane activity called the Atlantic Multi-decadal Oscillation (AMO) may now be over. The SST pattern associated with that cycle is absent this year, and NOAA said: "There have been two seasons in a row, 2013 and 2014, with below-normal and near-normal activity respectively and neither had an El Niño event responsible for the reduced activity. The current configuration of SSTs in the Atlantic Ocean, both in the MDR and the entire North Atlantic, are suggestive that the AMO may no longer be in the warm phase."

[WPBWeather]

I think the headline reads MAY BE (not IS) over. And as usual many of the other "experts" say it is too soon to really know.

It has ended

http://www.wunderground.com/blog/JeffMa ... rynum=2998

The forecasters cited the following main factors that will influence the coming season:

1) The current borderline weak/moderate El Niño event is expected to persist or intensify during the 2015 hurricane season. El Niño events tend to suppress Atlantic hurricane activity in three ways:

- By creating high levels of wind shear over the tropical Atlantic, which tends to tear storms apart.
- By increasing sinking motion and high pressure over the tropical Atlantic.
- By making the air more stable over the tropical Atlantic.

2) Near-average sea surface temperatures (SSTs) are in place over the hurricane Main Development Region (MDR), from the Caribbean to the coast of Africa between between 10°N and 20°N. These SSTs are expected to be near or below average during the peak August - October portion of hurricane season, and are expected to be cooler than SSTs in the remainder of the global tropics (SSTs in the remainder of the global tropics were 0.31°C warmer than SSTs in the MDR in May.) This configuration of SSTs is often quite hostile to Atlantic tropical cyclone development.

3) The active period of hurricane activity that began in 1995 due to a natural decades-long cycle in hurricane activity called the Atlantic Multi-decadal Oscillation (AMO) may now be over. The SST pattern associated with that cycle is absent this year, and NOAA said: "There have been two seasons in a row, 2013 and 2014, with below-normal and near-normal activity respectively and neither had an El Niño event responsible for the reduced activity. The current configuration of SSTs in the Atlantic Ocean, both in the MDR and the entire North Atlantic, are suggestive that the AMO may no longer be in the warm phase."

[Ptarmigan]

Another thing that occasionally happens, looking at history, as that even in non-El Nino years, if it's been a while since the last El Nino event, conditions eventually get rather unfavorable for big hurricanes in the Atlantic. 2013 is the most recent good example of this, but not the only one. Another quiet, non-El Nino year that immediately comes to mind is 1962, when it had been four years since the last El Nino. I also believe we were in an active period during that time, am I correct?

Or another front, sometimes those types of years favor quantity, but little quality. Think 1981 and 1990, for instance. 1981 had 12 storms (one being subtropical) and 1990 had 14. Yet, few of the storms in those two years got particularly strong for particularly long periods of time. I question Floyd from 1981's status as a Category 3 if its minimum pressure was 975 mb, as it looked like an average-sized hurricane...this could suggest a high-end Category 1 or a low-end Category 2 instead, but re-analysis will tell us in a few years or so. Only two other majors occurred that year, and one major very briefly occurred in 1990. (I don't question the intensities of those majors as much as Floyd in 1981 though.) The last El Nino event before each of these years was in 1977 and 1987, respectively, a fairly long gap between El Nino events.

It kind of begs the question, is there an irony that Atlantic hurricanes need El Nino every now and then in order to have more fuel pumped for when those events subside? Is the energy that hurricanes need sapped when El Nino doesn't take place often?

-Andrew92

1962 occurred in the warm phase or active phase of the Atlantic, which is from 1926 to 1969. The last El Nino was in 1959.

I think El Nino does recharge the Atlantic despite the fact that wind shear tends to kill any storm development. I notice seasons following El Nino tend to be active like 1995, 1998, 2005, and 2010. There are even active seasons during El Nino like 1969 and 2004. The El Nino was weak at the time. The exceptions are 1973 and 1983, but they occurred during cool phase or less active phase of the Atlantic. Interesting to note that the 1983 Typhoon season was not that active. However, East Pacific was hyper active that time. This was during a developing La Nina.

[TheStormExpert]

Yeah it is WAY TOO SOON to be jumping to any sudden conclusions that the Active Era has ended.

First off, we need to see what effect this current El Niño episode has on the Atlantic in terms of MAYBE improving the lack of Vertical Instability in the MDR.

Just cause 2013, and 2014 were both below normal seasons in two different ways (2013 featuring an Avg. # of storms, but very few hurricanes. While 2014 had below Avg. # of storms, but Avg. # of hurricanes). Doesn't mean we are instantly through with the current Active Era.

This is also the first El Niño event in Six years! That is a long stretch to go without an El Niño event, though similar stretches have occurred before. These El Niño events are kind of a way of letting the Atlantic recharge and refuel.

IMO WE WILL NOT know the if the Active Era is over until about the end of 2017 which gives a few more hurricane seasons to analyze the trends after this season.

Even WxMan57 stated earlier this year that he thinks it might not be over. His thought was that this Active Era sticks out for having very few Cold AMO years and in recent Active Eras you'd see a few years of a dip into Cold AMO territory before going back into the Warm AMO territory again.

[Ptarmigan]

:uarrow: Yeah it is WAY TOO SOON to be jumping to any sudden conclusions that the Active Era has ended.

First off, we need to see what effect this current El Niño episode has on the Atlantic in terms of MAYBE improving the lack of Vertical Instability in the MDR.

Just cause 2013, and 2014 were both below normal seasons in two different ways (2013 featuring an Avg. # of storms, but very few hurricanes. While 2014 had below Avg. # of storms, but Avg. # of hurricanes). Doesn't mean we are instantly through with the current Active Era.

This is also the first El Niño event in Six years! That is a long stretch to go without an El Niño event, though similar stretches have occurred before. These El Niño events are kind of a way of letting the Atlantic recharge and refuel.

IMO WE WILL NOT know the if the Active Era is over until about the end of 2017 which gives a few more hurricane seasons to analyze the trends after this season.

Even WxMan57 stated earlier this year that he thinks it might not be over. His thought was that this Active Era sticks out for having very few Cold AMO years and in recent Active Eras you'd see a few years of a dip into Cold AMO territory before going back into the Warm AMO territory again.

Or vice versa in less active phase. There are spikes of warm AMO like in 1980, 1988, and 1989.

[Andrew92]

1989 was another such year that fell in that dreaded second year after the most recent traditional El Nino season. And look what happened that year.....

The one unusual thing about that season was that no major hurricanes reached the Gulf of Mexico. Only three other seasons that fell in the second year after the most recent traditional El Nino since 1960 met that criteria: 1984, 1996, and 2011.

It should be noted in my statement above that 1985 acted a lot more like the second year after the most traditional El Nino than 1984 did. Those years tend to have at least one long-tracking hurricane reach the East Coast; 1985 had one in Gloria but 1984 had none. They have more Caribbean activity as well; neither 1984 or 1985 had much, but 1985 saw Elena form there and Kate clipped the north coast of Cuba, while 1984 just had Klaus. They also have less storms forming from frontal lows off the East Coast or further out; 1985 had Ana and Claudette, but 1984 had a subtropical storm, Cesar, Diana, Gustav, Hortense, Josephine, and Lili.

But both 1984 and 1985 had the big characteristic of a second year after the most recent traditional El Nino year: a hurricane with a pressure below 965 millibars reaching the United States coast. True, Diana didn't actually make landfall with its pressure that low, but it did graze by Cape Fear with such a pressure, and I believe I once read that Category 3 winds did briefly reach the coast there, though I admit it may have come slightly above the surface. 1985 featured Elena as a true Category 3 and Gloria with a pressure of 942 mb on Cape Hatteras and 961 in Long Island and New England.

Maybe that inactive Atlantic phase and active EPAC phase had something to do with this seeming lag time for El Nino-like conditions to completely disappear in North America after the 1972 and 1982 events.

-Andrew92

[xtyphooncyclonex]

2009 was a traditional Niño prior to intensifying to moderate as warmer anomalies shifted further west. 2015 is already a moderate Niño yet traditional, which means 2017 is a year to watch given your theory

[cycloneye]

Dr Klotzbach delivers more bad news for the North Atlantic.

Philip Klotzbach
‏@philklotzbach
Real-time AMO index from Klotzbach and Gray (2008) lowest May value on record (back to 1950).

Eric Blake ‏@EricBlake12 1h1 hour ago
@philklotzbach Phil you are full of good news this morning. It isn't the best seasonal fcst parameter right? More long term?

Philip Klotzbach ‏@philklotzbach 1h1 hour ago
@EricBlake12 correct. But, the long term trend indicates a whole lot of nothing for the Atlantic!

[wxman57]

I think we need another 2-3 years of data to confirm any flip. The past 2 warm cycles featured 1-2 periods like we're observing now, and these cool years were followed by another 10-15 years of warmth.

[WPBWeather]

Klotzbach and Gray have been not all that accurate with seasonal forecasts for a few years now. Not sure they--or anyone else-- have "the handle" on the future of the tropical Atlantic either.

[xcool22]

I think active era since ended after 2008 imo grain of salt

[Yellow Evan]

I think active era since ended after 2008 imo grain of salt

2008? 2010-2012 were all above average seasons.

[WPBWeather]

Let's all meet back here in 3-4 years and see what happened...

[xcool22]

I mean 2005 not 2008

[Yellow Evan]

I mean 2005 not 2008

By that argument, 1995-2003 isn't any much more active than 2006-2012.

[xcool22]

i agree with you that is true

[Yellow Evan]

i agree with you that is true

So, why is 2005 the end of the active era? And not 2012?

[xcool22]

there's a lot of factors

[gatorcane]

Another thing that occasionally happens, looking at history, as that even in non-El Nino years, if it's been a while since the last El Nino event, conditions eventually get rather unfavorable for big hurricanes in the Atlantic. 2013 is the most recent good example of this, but not the only one. Another quiet, non-El Nino year that immediately comes to mind is 1962, when it had been four years since the last El Nino. I also believe we were in an active period during that time, am I correct?

Or another front, sometimes those types of years favor quantity, but little quality. Think 1981 and 1990, for instance. 1981 had 12 storms (one being subtropical) and 1990 had 14. Yet, few of the storms in those two years got particularly strong for particularly long periods of time. I question Floyd from 1981's status as a Category 3 if its minimum pressure was 975 mb, as it looked like an average-sized hurricane...this could suggest a high-end Category 1 or a low-end Category 2 instead, but re-analysis will tell us in a few years or so. Only two other majors occurred that year, and one major very briefly occurred in 1990. (I don't question the intensities of those majors as much as Floyd in 1981 though.) The last El Nino event before each of these years was in 1977 and 1987, respectively, a fairly long gap between El Nino events.

It kind of begs the question, is there an irony that Atlantic hurricanes need El Nino every now and then in order to have more fuel pumped for when those events subside? Is the energy that hurricanes need sapped when El Nino doesn't take place often?

-Andrew92

Yeah I do wonder if El Ninos are needed to get big hurricanes in the Atlantic. Very interesting theory. Also were any of the active years in the 20s-40s el niño years that featured big Atlantic hurricanes or do we not have el nino data that goes back that far?

[Andrew92]

there's a lot of factors

Can you please explain what factors make 2005 the end of the active era then and not 2012? (if that)

I mean, I can understand that the United States hasn't had a lot of hurricane hits since then, but that doesn't mean they haven't been out there. They have been there, just in different locations, such as in the Caribbean and Central America, in the far open Atlantic, or in some instances, Bermuda or the Canadian Maritimes.

It has been discussed by a few members here that all of the hurricanes that took place in 2010, 2011, and 2012 was at least somewhat responsible for sapping the Atlantic of the energy needed for hurricanes to develop and sustain themselves. It is also believed by some that El Nino, although unfavorable while it is actually occurring for Atlantic hurricane development, can cause conditions in the years that follow when the El Nino dissipates to become more favorable for these storms to get going.

Add this all up, and it is too early to signal the end of the active era. Now if things are still quiet in the Atlantic in 2016 and 2017, then we are getting closer to saying so, if not outright saying it altogether.

-Andrew92