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2016 Atlantic Hurricane season


Jason WX

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 (First post) Well. Only 5 months time. Through the rest of winter, the El Nino will collapse. There is a high chance we could see neutral or even a La Nina. Waters of E. coast are still very warm and could pose a threat if it persists. We'll see. Only a matter of time.

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Also it could be noted that NHC are monitoring the low near Bermuda for possible subtropical storm designation, thought to be 30 per cent possible when it gets closer to the Azores in 2-4 days time. Regardless, this low has tropical storm force winds. As it would be numbered and named in the 2016 series, it belongs here although most of us would think of it as an afterthought of the 2015 season. The lowest frequency of storms is actually Feb-Mar so that is probably the real divide of seasons, the calendar year is not quite the best fit possible to this seasonal cycle. I regard the Feb 1952 and March 1908 cases as rogue events that don't really belong to either season, anything in April would be the earliest signs of a new season. But others may have other ideas about that.

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I know that they're both long-range outlooks, but both CanSIPS and the CFSv2 are showing a rather –AMO by peak season (September), with cooler-than-average anomalies in the North Atlantic and the warmest anomalies concentrated along the Eastern Seaboard/off the Northeastern U.S. This is consistent with a weakened AMOC. Of course, there are some major differences, with CanSIPS showing a warmer Caribbean and a cool eastern Pacific with a strong La Niña ongoing, while the CFSv2 is quite the opposite and overall more unfavorable for the Atlantic (–AMO plus enhanced shear via EPAC forcing). The December '15 ECMWF long-range forecast doesn't extend beyond June, but also shows a similar SST configuration in the Atlantic: warmest anomalies off the East Coast, relatively cooler anomalies in the MDR, below-average anomalies in the North Atlantic. So the model consensus seems to be that the AMO won't be particularly favorable this upcoming season.

 

Overall, how much the AMO rebounds from its current low will depend in part on the state of the NAO in JFM. We would need a mean –NAO this month and a strongly negative –NAO in February/March to really allow a substantial weakening of the trades and a big warm-up in the MDR. Down the line, the MJO, the rate of decay of El Niño, and the state of the IOD will also be important, especially if the AMO does not recover. Another thing to keep in mind is that a –AMO correlates with a weakened subtropical high and more development outside the deep tropics, meaning that storms, when available, are much more likely to curve out to sea, which would mean that the U.S. would likely go yet another year without a major (and possibly any hurricane) landfall. If we are indeed in an altered climate regime, then we could go another decade or more without any major U.S. landfalls, given that the current global climate regime is something that we have not observed in modern times.

 

Overall, my sense is that the Atlantic may be dead for the foreseeable future, with the mean activity shifting over into the Pacific, given the rate of SST warming over there and the likelihood for more active MJO periods.

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What am I missing? Those maps look like a +AMO to me...very positive for the CFS. The tropical Pacific looks less favorable for the Atlantic in the CFS but it's the JJA period vs August only in CanSIPS, and is clearly in a cooling trend.

Compared to 1997-2012, the 2013-15 period shows clear cooling trends in the deep tropics, especially near the Caribbean, along with noted cooling southeast of Greenland and warming off the East Coast/Northeastern U.S. According to Dr. Phil Klotzbach, these trends signal a weakening or reversal of the AMOC/+AMO due in part to solar activity, the NAO, and climate change. The CFSv2 (see Levi Cowan's site for the monthly data) and CanSIPS show the bulk of the warmest anomalies near the Eastern Seaboard with relatively cooler but still positive anomalies in the MDR, though the CFS shows below-average SST in the Caribbean by September. I haven't seen anyone suggesting that the AMO will be favorable this upcoming season, given that it has to recover significantly between now and peak season.

 

Here you can see the influence of the +NAO trend:

 

vpGbcGG.png

 

Note the impact on SST anomalies:

K34cNm0.jpg

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Also it could be noted that NHC are monitoring the low near Bermuda for possible subtropical storm designation, thought to be 30 per cent possible when it gets closer to the Azores in 2-4 days time. Regardless, this low has tropical storm force winds. As it would be numbered and named in the 2016 series, it belongs here although most of us would think of it as an afterthought of the 2015 season. The lowest frequency of storms is actually Feb-Mar so that is probably the real divide of seasons, the calendar year is not quite the best fit possible to this seasonal cycle. I regard the Feb 1952 and March 1908 cases as rogue events that don't really belong to either season, anything in April would be the earliest signs of a new season. But others may have other ideas about that.

 

My thoughts on this are pretty similar. Since the season runs from June to November, I'd include anything in December, January, or February as a "late season" storm and anything in March, April, or May to be part of a new season.

 

BTW, this system is now designated Invest 90L. 

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Surface analyses by TAFB at 12Z indicate that the surrounding air mass has sufficiently modified so that 90L has practically shed its cold front. The system is more symmetric than previously, there are hints of mid-level anticyclonic flow as the cold-core trough shears out. Satellite imagery shows a steady improvement in organization, with a concentrated area of convection and even a formative eye, though the structure is still a bit tilted overall. The system actually looks to be transitioning straight to tropical status without an intermediate stage, though the switch will only last about a day or so, as the system is already curving northeast and leaving warmer SST (it is already over an area with below-average anomalies thus far). Nevertheless, the system looks to have winds approaching hurricane status at this time (55-60 kt). It seems likely to become a hurricane-strength system shortly. Maybe it will be upgraded in a post-seasonal analysis, making it one of only two Atlantic cyclones to reach hurricane status in January. Amazing...

 

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NHC will initiate advisories on Subtropical Storm Alex, located over the far eastern Atlantic Ocean, at 4 pm EST/2100 UTC.

 

From the official NHC site (Special Message). This would likely mark the first coincidence (simultaneous occurrence) of two January tropical cyclones in the Atlantic and Central Pacific, respectively, and definitely marks the first January Atlantic TC since 1978.

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Wow... Did not expect this to ever look this good moving over 22-23° SSTs. The much colder pool aloft and low shear around the LLC must have allowed an eyewall to form and strengthen. I don't suppose we'll ever know if it's actually supporting sustained hurricane force winds, but there is no doubt this is a very rare warm core event for the system to be this healthy so late in January.

Sent from my LG G4.

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ftp://ftp.nhc.noaa.gov/atcf/btk/bal012016.dat

AL, 01, 2016011412,   , BEST,   0, 308N,  287W,  75,  981, HU,  34, NEQ,  120,  130,  100,   30, 1012,  300,  15,  90,   0,   L,   0,    ,   0,   0,       ALEX, D, AL, 01, 2016011412,   , BEST,   0, 308N,  287W,  75,  981, HU,  50, NEQ,   30,   30,    0,    0, 1012,  300,  15,  90,   0,   L,   0,    ,   0,   0,       ALEX, D, AL, 01, 2016011412,   , BEST,   0, 308N,  287W,  75,  981, HU,  64, NEQ,   20,   20,    0,    0, 1012,  300,  15,  90,   0,   L,   0,    ,   0,   0,       ALEX, D, 

I don't suppose we'll ever know if it's actually supporting sustained hurricane force winds

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Alex became only the 3rd Atlantic hurricane on record in January. Alex is also the strongest such hurricane on record with maximum sustained winds of 75 knots. An unnamed hurricane in January 1938 and Alice (1955) had peak maximum sustained winds of 70 knots.

 

And Alice formed in December, so Alex is the first hurricane to form in January since 1938.

 

It should be noted that most January systems have occurred in the first week of the month (1938, 1951, Alice, Zeta). In fact, Alex is only the 4th classified system to occur in the dead time between January 10 and April 15 -- and it is only the second hurricane, after the March 1908 hurricane.

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Alex became only the 3rd Atlantic hurricane on record in January. Alex is also the strongest such hurricane on record with maximum sustained winds of 75 knots. An unnamed hurricane in January 1938 and Alice (1955) had peak maximum sustained winds of 70 knots.

Don, I'd kindly wish to correct you. Reanalysis has upgraded ALICE's peak winds in January to 80 kt on 2 January, making ALEX the second strongest. ALEX also happens to be the second most northeasterly hurricane on record in the basin, behind only VINCE in 2005.

 

Best wishes!

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Don, I'd kindly wish to correct you. Reanalysis has upgraded ALICE's peak winds in January to 80 kt on 2 January, making ALEX the second strongest. ALEX also happens to be the second most northeasterly hurricane on record in the basin, behind only VINCE in 2005.

 

Best wishes!

Thanks for the correction. I had missed the upgrade.

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Alex became only the 3rd Atlantic hurricane on record in January. Alex is also the strongest such hurricane on record with maximum sustained winds of 75 knots. An unnamed hurricane in January 1938 and Alice (1955) had peak maximum sustained winds of 70 knots.

Awesome!

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Considering the date and location, this has to be one of the most impressive hurricanes in history. The SST difference versus the extreme cold air aloft will not remain capable of lapse rates to support such impressive structure much longer. The SSTs will be in the mid-to-upper teens near the Azores. Instability will be decreasing from here on out. However, baroclinic forcing should keep windspeeds near hurricane force in gusts at least in the eastern semicircle as it passes through the Azores. The overall windfield should have expanded eastward by the time it reaches those islands as well. Will be interesting to see how Alex can maintain intensity as it will begin transitioning away from a warm core soon and furthermore what kind of surface winds those islands end up experiencing.

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