Thoughts on 2013 Atlantic Hurricane Season

[Ntxw]

MJO is over the Maritimes and will be nearing the Pacific. Euro (bias corrected) has performed well predicting its movement. While we do not need the MJO to spawn systems in the Atlantic it certainly won't be a helping factor as sinking air will be favored in the western hemisphere next 5-7 days. Most recent favorable trip of the MJO gave us Gabrielle, Humberto, and Ingrid. It will take awhile for the next favorable trip of the MJO to return (if at all) possibly early Oct at the earliest.

[gatorcane]

Scraping for disturbances out of Africa. The Cape Verde Belt has dried up for now.

Cape Verde season typically winds down around this time of year. I wonder if Humberto will be the last system?

[otowntiger]

But still the storms didn't form as expected.

But isn't that the main thing, really the only thing. Sure all the predictors were accurate in terms of lower pressures, sst's etc, but all that does is point to the obvious in that we are missing something in considering the seasonal predictions.

[TropicalAnalystwx13]

The red north of 30N is the biggest contributor for why this season has underperformed.

[CrazyC83]

That red could fuel Humberto in the next couple days - possibly as a post-tropical storm though

[TheStormExpert]

The red north of 30N is the biggest contributor for why this season has underperformed.

http://i.imgur.com/FiJnbGN.png

How though? There's still some red in the Tropics though. Also notice the evident blue spot in the BoC from upwelling when Ingrid was meandering around.

[WeatherGuesser]

Next

[Andrew92]

TropicalAnalyst, I must say I am intrigued in this finding. Give me a short while to see what other years have had this same warmer than normal water in these higher latitudes and discover trends. I will get back to this shortly.

-Andrew92

[Andrew92]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

OK after doing a little bit of research on years with these warm anomalies in the mid- to higher latitudes, I found twenty years that had similar warm anomalies in the satellite era:

1960
1961
1967
1983
1984
1988
1989
1990
1994
1998
2000
2001
2002
2003
2005
2006
2007
2008
2011
2012

There are a couple of things to take away from these years. The average number of storms to form in the Main Development Region is about four. Five years in this set did see more than five storms form in the Main Development Region: 1989, 1990, 1998, 2000, and 2012. The most active of these years were 1989 and 1998 by a wide margin, with five hurricanes in 1989 and six in 1998 (though one was barely a hurricane in each year). Yet even those two years only managed two majors from these types of storms, although 1998 did also produce Mitch in the Caribbean. 1990 also saw seven storms form there, but only three of them becoming hurricanes with only one barely becoming a major (and one of the ones that became a hurricane was barely one, too). Two MDR storms became major hurricanes in 2000, but also curved further north while the westbound storms fizzled quickly. And out of two MDR storms in 2012, only two became hurricanes at all, neither a major.

The rest of the fifteen years in the dataset - even including 2005 - had little activity in the MDR. Yet only one year had no tropical storms at all in that area, and that was El Nino-laden 1983.

Also, you may have noticed the dataset of 1967, 1984, 1988, 2001, and 2002 pop up at times coming into September of this year. The reason is those years had no hurricanes form until September. Did you also happen to catch that every one of those years met the warm anomalies in the subtropical Atlantic rule that has potentially been discovered? The next time we have no hurricanes before September (a rarity, admittedly), this might be a pretty good indicator to look at, although the sample size is still quite small.

I must note, however, that quite a few of these years also featured a mixture of some cooler waters as well. If I were to name the years most similar to this year of this set, I would say 1960, 2000, and 2001. 1960 saw actually quite warmer anomalies than this year although somewhat more to the south, while 2000 and maybe moreso 2001 look like carbon copies of this year. Storms really struggled to get going in the tropics in all three years, although Donna did still become quite the classical hurricane. The westward moving storms in 2000 and 2001 struggled mightily as a whole, with a few exceptions further west in the Caribbean in Keith, Iris, and Michelle. Some of the quick re-curvers did intensify a little more, most namely Isaac in 2000 but also including Alberto, Erin, and Felix.

This was a rather quick research job and I would be intrigued to learn more but I have simply run out of time for tonight. If there is anything that is telling me about this, I am not sure why storms sometimes struggle in years with warmer waters off New England and/or the Maritimes, but I think our best bet for major hurricane activity will come in October in the Western Caribbean. This is corroborated further when you consider how dry and stable the MDR has been as a whole this year. However, if conditions had been a little more favorable I would say Humberto pulling off become a major briefly on its way out to sea could have a stronger probability. As it stands, that looks quite unlikely, but I can't entirely rule it out.

-Andrew92

[TropicalAnalystwx13]

The red north of 30N is the biggest contributor for why this season has underperformed.

http://i.imgur.com/FiJnbGN.png

How though? There's still some red in the Tropics though. Also notice the evident blue spot in the BoC from upwelling when Ingrid was meandering around.

Warm waters above 30N broaden and weaken the Hadley Cell...means less rising air and vertical instability in the deep tropics. Of course there are other factors, but this is the factor of most significance.

[Ptarmigan]

The red north of 30N is the biggest contributor for why this season has underperformed.

http://i.imgur.com/FiJnbGN.png

Interesting you mention that. I wonder why the water further north is warmer than further south.

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

OK after doing a little bit of research on years with these warm anomalies in the mid- to higher latitudes, I found twenty years that had similar warm anomalies in the satellite era:

1960
1961
1967
1983
1984
1988
1989
1990
1994
1998
2000
2001
2002
2003
2005
2006
2007
2008
2011
2012

There are a couple of things to take away from these years. The average number of storms to form in the Main Development Region is about four. Five years in this set did see more than five storms form in the Main Development Region: 1989, 1990, 1998, 2000, and 2012. The most active of these years were 1989 and 1998 by a wide margin, with five hurricanes in 1989 and six in 1998 (though one was barely a hurricane in each year). Yet even those two years only managed two majors from these types of storms, although 1998 did also produce Mitch in the Caribbean. 1990 also saw seven storms form there, but only three of them becoming hurricanes with only one barely becoming a major (and one of the ones that became a hurricane was barely one, too). Two MDR storms became major hurricanes in 2000, but also curved further north while the westbound storms fizzled quickly. And out of two MDR storms in 2012, only two became hurricanes at all, neither a major.

The rest of the fifteen years in the dataset - even including 2005 - had little activity in the MDR. Yet only one year had no tropical storms at all in that area, and that was El Nino-laden 1983.

Also, you may have noticed the dataset of 1967, 1984, 1988, 2001, and 2002 pop up at times coming into September of this year. The reason is those years had no hurricanes form until September. Did you also happen to catch that every one of those years met the warm anomalies in the subtropical Atlantic rule that has potentially been discovered? The next time we have no hurricanes before September (a rarity, admittedly), this might be a pretty good indicator to look at, although the sample size is still quite small.

I must note, however, that quite a few of these years also featured a mixture of some cooler waters as well. If I were to name the years most similar to this year of this set, I would say 1960, 2000, and 2001. 1960 saw actually quite warmer anomalies than this year although somewhat more to the south, while 2000 and maybe moreso 2001 look like carbon copies of this year. Storms really struggled to get going in the tropics in all three years, although Donna did still become quite the classical hurricane. The westward moving storms in 2000 and 2001 struggled mightily as a whole, with a few exceptions further west in the Caribbean in Keith, Iris, and Michelle. Some of the quick re-curvers did intensify a little more, most namely Isaac in 2000 but also including Alberto, Erin, and Felix.

This was a rather quick research job and I would be intrigued to learn more but I have simply run out of time for tonight. If there is anything that is telling me about this, I am not sure why storms sometimes struggle in years with warmer waters off New England and/or the Maritimes, but I think our best bet for major hurricane activity will come in October in the Western Caribbean. This is corroborated further when you consider how dry and stable the MDR has been as a whole this year. However, if conditions had been a little more favorable I would say Humberto pulling off become a major briefly on its way out to sea could have a stronger probability. As it stands, that looks quite unlikely, but I can't entirely rule it out.

-Andrew92

Interesting find. I notice some of those years you mention were quite active like 1961, 1998, 2000, 2001, 2003, 2005, and 2008. 2008 was quite favorable for Cape Verde storms, while 2005 was not.

[Andrew92]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Actually, only four storms were able to get going in the MDR in 2008: Bertha, Ike, Josephine, and Nana (which was barely a tropical storm I might add). A surprising amount of the activity that year was homegrown.

I could see this year being a lot like 2000 or 2001 from a Cape Verde standpoint. If you look at the storms this year in that region, Chantal and Dorian were westbound storms that weakened quickly in unfavorable environments - you could think of storms like Chris, Debby (even though it managed to become a hurricane), and Ernesto in 2000, and Chantal in 2001 (though she got stronger further west in the Caribbean where she nearly became a hurricane, a track not seen this year). Erin weakened even sooner. But Humberto went further north and has managed to become a hurricane, much like Alberto and Isaac in 2000 and Felix in 2001.

But the comparison to those two years still is not complete. The storms to hit the US in those two years also primarily head the Florida Panhandle - four out of five. The one obvious exception is Allison, but look at the paths of Gordon and Helene in 2000, and Barry and Gabrielle in 2001. Now compare those to Andrea - especially look at Gordon and Gabrielle. Look similar? About the only difference between Andrea and those four storms is the time it occurred. Except for Barry (an August storm), the other three were all in September, but Andrea was in early June. One quick caveat to the aforementioned Allison: one thing that often goes completely overlooked is that in 2000, there was a tropical depression that made landfall near the exact same location, also in September.

Now, when looking at a live case scenario, being Invest 95L, we have quite a model spread. Some models take that disturbance to Mexico, some to Louisiana, and some to Florida. Generally, in those two years, storms in this area kept going west. This includes Beryl and Keith in 2000. Admittedly, no storms reached the Bay of Campeche in 2001, but Chantal and Iris were the closest and kept heading in that direction. However, we did see in Ingrid recently a storm that did tug a little more north than storms in those two years. There are hints of a strong ridge over Texas breaking down to allow a storm coming out of this area to make such a turn. However, I would tend to think such a turn would carry a storm closer to Louisiana than Florida if it comes out of the Bay of Campeche. A storm off the northeast tip of the Yucatan would have a better chance of reaching Florida, in my opinion.

None of the storms that reached the US became hurricanes, but Gordon weakened from a hurricane, and Barry and Gabrielle were close and intensifying up to landfall. Based upon this, if 2000 and 2001 are among the best analogs for this year, this area probably stands the best chance of seeing a hurricane strike out of anywhere in the US for the remainder of this season. I also tend to think it would best come from a storm already well-established in the Western Caribbean, ala Michelle which just missed to the south.

With some fairly good agreement of something taking place in this region in the coming days, this is definitely worth a long look to see if any more comparisons to 2000 or 2001 are to be warranted.

Lastly, as I typed that last sentence, I thought of a couple more quick comparisons. Compare this year's Gabrielle to Dean in 2001. Look similar? The only difference I see is Dean managed to grow stronger in probably a more moist and less stable environment. The last being, 2001 saw its first hurricane form on September 9, with this year coming a scant two days later.

Needless to say, I am very intrigued to discover if anything else that happened in 2000 and 2001 in the atmosphere are taking place that I am unaware of currently, along with if these have occurred in other years like this one.

-Andrew92

[ninel conde]

Scraping for disturbances out of Africa. The Cape Verde Belt has dried up for now.

Cape Verde season typically winds down around this time of year. I wonder if Humberto will be the last system?

most likely. satellite this morning shows nothing. it does show that the nw african trof has moved se into africa. that should stop anything from developing.

[gatorcane]

Past the peak by over a week now and here is our current map for this year. Who would have thought it would have been this lackluster to date?

[ConvergenceZone]

To make up for the lack of excitement this year in the tropics, I hope California(where I live) gets some crazy strong winter storms this year..I have a feeling we will get dumped on this year......

['CaneFreak]

Lots of shear this season for a non-El Nino year. Still perplexed by the unfavorable conditions so far given the overall state of the ocean and atmosphere.

[ninel conde]

Past the peak by over a week now and here is our current map for this year. Who would have thought it would have been this lackluster to date?

nothing of importance likely to form anytime soon either. even the BOC has become less favorable.

[Ntxw]

Atlantic is sitting at 23.055 ACE or 34%. Nothing big/strong and long tracking looks imminent the next week so we probably won't add much to this number the rest of September. We'll need an insanely wild October/November of activity or one massive tracking CV storm like Igor of 2010 to get back to normal levels. A Nadine 2012 like storm for a few weeks will probably get us above 50%. Given the state of the season so far and MJO not favorable, I would not put bets on either of those options happening. Caribbean and southern gulf looks better but even here developments for the most part have taken it's sweet time to get going if at all.

We currently are on pace ACE wise with the El Nino's. And since the +AMO flip in 1995 this kind of quietness is matched only by the bigger El Nino's such as 1997, 2002, and 2009. All three featured a major hurricane before Sept 22, we likely will go longer if not through the rest of Sept and maybe early Oct and beat those years in that regard.

[ninel conde]

im not too confident of a big oct. gfs shows a strong neg NAO may be developing. i still think the season ends early.

Joe Bastardi ‏@BigJoeBastardi 1h

With 9 storms and a total ace of 23, this currently rates as the lowest ace/storm season since 1950

[supercane4867]

The Atlantic is died.