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Atlantic Tropical Action 2013


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I like the subsidence idea. Whatever is going on its a multi-year situation. it’s not that we haven’t seen development the last few years it’s that we haven’t seen ideal conditions in the MDR for anything more than struggling trop storms.

I think climate change may have some impact as we see shear increasing in the tropics in general. This fits in with the idea that despite warming sea surface temps increasing shear will counteract any increase in available energy.

I certainly don't want this to turn into a climate change debate, but you cannot on the one hand blame 2005 with all its many great storms on climate change and then blame 2013 and its lameness on climate change for completely opposite reasons.  It's just weather, and over time it become part of climo.

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I certainly don't want this to turn into a climate change debate, but you cannot on the one hand blame 2005 with all its many great storms on climate change and then blame 2013 and its lameness on climate change for completely opposite reasons.  It's just weather, and over time it become part of climo.

 

 

I haaaaate climate change debates myself but shear is shear and in my opinion its anomalously high this season and that very well may be impacted by climate change. Let’s take 32c water temps and super moist environment. Throw a trop storm into that situation and some 3o knot shear and wam nothing. Shear is king!

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I haaaaate climate change debates myself but shear is shear and in my opinion its anomalously high this season and that very well may be impacted by climate change. Let’s take 32c water temps and super moist environment. Throw a trop storm into that situation and some 3o knot shear and wam nothing. Shear is king!

 

It's pretty clear the most serious impediment to development this year is NOT shear, and shear in the MDR this month has actually been a bit below normal.

 

We're not seeing an endless procession of promising systems getting decapitated as happens in an El Nino.

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It's pretty clear the most serious impediment to development this year is NOT shear, and shear in the MDR this month has actually been a bit below normal.

 

We're not seeing an endless procession of promising systems getting decapitated as happens in an El Nino.

 

i meant earlier in the season to clarify sorry. This month its been SAL and lack of waves no?

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With Atlantic SSTs the way they are, and given Neutral/cool ENSO current and forecasts, if a near lid on tropical cyclones remains, is there any effect on our autumn or winter without the heat transport to higher latitudes that is the purpose of these storms? Especially in light of the rather cold Arctic summer.

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Recap of US E coast threatening runs from pouch 25:

 

-0Z 8/24 Euro has strengthening TC 19N, 55W as of 0Z 9/3, moving W with implied E coast threat ~9/7-8

-6Z 8/24 GFS hits S FL 9/7

-6Z 8/25 GFS hits ME ~9/7-8

-0Z 8/29 CMC has 976 mb H 29N, 72W as of 0Z 9/8 moving NW and suggesting NC nward threat 9/8-9

-12Z 8/30 CMC hits Wilmington, NC, with a 968 H late 9/8

 

 So, the Euro and GFS actually had on runs 5-6 days back an actual US E coast threat from pouch 25 and for about the same period, near 9/8.. Let's  see if more models join the CMC in the coming days or if the CMC abandons its threats as usually happens when it is on its largely on its own. The key threat period centers around 9/8.

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i meant earlier in the season to clarify sorry. This month its been SAL and lack of waves no?

 

Again my hypothesis is that the waves have actually been stronger than normal, which has drawn them further north into cooler waters, higher shear, and more stable SAL induced air. In order for stronger waves to thrive, you need a strong 500 hPa ridge to keep them on a 10-12N westward path. That has been absent this past month. 

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Again my hypothesis is that the waves have actually been stronger than normal, which has drawn them further north into cooler waters, higher shear, and more stable SAL induced air. In order for stronger waves to thrive, you need a strong 500 hPa ridge to keep them on a 10-12N westward path. That has been absent this past month. 

I read this yesterday, and I give it weight.  I am fond of counter-intuitive reasoning to explain phenomena.  However, doesn't a stronger wave induce a stronger 500 hPa ridge for the wave behind it?? 

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Again my hypothesis is that the waves have actually been stronger than normal, which has drawn them further north into cooler waters, higher shear, and more stable SAL induced air. In order for stronger waves to thrive, you need a strong 500 hPa ridge to keep them on a 10-12N westward path. That has been absent this past month. 

 

Yeah, the waves coming off of Africa have been losing support as they traversed the more stable Tropical Atlantic. Quite an impressive rising and sinking air couplet for those areas. More of an extreme impact this year  so far compared

to the similar conditions of recent years though. Perhaps the JUL-AUG MJO being in COD so long as

opposed to more favorable phases of recent summers just amplified the effect. At least the storms 

struggling through the Tropical Atlantic in the last few  years were able to intensify further west. We only 

had on storm reach hurricane strength briefly in the Tropical Atlantic since 2011.

 

 

 

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The maps bluewave posted show a pretty strong inverse relationship between convection on land and convection over sea. Maybe we are in a negative phase of some yet undiscovered oscillation where the former is enhanced and the latter is suppressed?

 

And as for the waves emerging pretty far north, that may have something to do with it as well. The Azores weakness has been pretty strong this year.

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I haaaaate climate change debates myself but shear is shear and in my opinion its anomalously high this season and that very well may be impacted by climate change. Let’s take 32c water temps and super moist environment. Throw a trop storm into that situation and some 3o knot shear and wam nothing. Shear is king!

 

I hate using climate change too but I recall some studies are emerging which supposedly predict global warming will reduce global TC activity (which, from what I recall, has been the case this past decade).

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 Hot off of the press from another BB from the very well-respected meteorologist and often downplayer of tropical threats, "wxman 57":

 

" I see a major change coming after Sept. 9th in the GFS & Canadian ensembles as well as Japanese model (my coworker tells me). Check out the North Atlantic panel and the '500mb Geopotential Height Anomaly' maps. Note that after the 8th, the ridge builds across the Atlantic but is located a lot farther north than normal. This is a pattern that opens up the tropics for development and also indicates less recurving storms:"

 

 In the bigger picture, I still think that the current neutral negative ENSO is more favorable than unfavorable for a
major US threat sometime this season and I'm still betting on a major US H hit at some point (2/3 chance in my mind). There's plenty of time for that. That's in addition to the current strong MJO phase 1.

 

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 Hot off of the press from another BB from the very well-respected and often downplayer of tropical threats, "wxman 57":

 

" I see a major change coming after Sept. 9th in the GFS & Canadian ensembles as well as Japanese model (my coworker tells me). Check out the North Atlantic panel and the '500mb Geopotential Height Anomaly' maps. Note that after the 8th, the ridge builds across the Atlantic but is located a lot farther north than normal. This is a pattern that opens up the tropics for development and also indicates less recurving storms:"

 

 In the bigger picture, I still think that the current neutral negative ENSO is more favorable than unfavorable for a

major US threat sometime this season and I'm still betting on a major US H hit at some point (2/3 chance in my mind). There's plenty of time for that. That's in addition to the current strong MJO phase 1.

 

 

Wow.  Rare piece o' good news.  Like you said, the 57 dude has some cred.

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The models have some lower height anomalies across the tropical MDR region which may or may not indicate activity. Even so, this is the time of year when ingredients come together. It's obviously not going to be this quiet over the next 10-12 weeks. Patience will pay off eventually.

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Hot off of the press from another BB from the very well-respected meteorologist and often downplayer of tropical threats, "wxman 57":

" I see a major change coming after Sept. 9th in the GFS & Canadian ensembles as well as Japanese model (my coworker tells me). Check out the North Atlantic panel and the '500mb Geopotential Height Anomaly' maps. Note that after the 8th, the ridge builds across the Atlantic but is located a lot farther north than normal. This is a pattern that opens up the tropics for development and also indicates less recurving storms:"

In the bigger picture, I still think that the current neutral negative ENSO is more favorable than unfavorable for a

major US threat sometime this season and I'm still betting on a major US H hit at some point (2/3 chance in my mind). There's plenty of time for that. That's in addition to the current strong MJO phase 1.

Its always a good thing when wxman 57 is bullish (and rare) lol ,i was on that board many of the years i was in s fl. So finally something to look fwd too in 10 days

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Folks,

 We have kind of an interesting situation regarding pouch 25 in the central Atlantic. Whereas the GFS and Euro runs (through 12Z) continue to do nothing with it, the CMC for at least the 4th run in a row has it become a cat 2-3 hurricane and threaten the US east coast. As a matter of fact, today's 12Z CMC actually slams Wilmington with a 968 mb hurricane at hour 216. See the attached map. Actually, it forms a TD by Monday morning 9/2 (72 hours) near the Leewards. Normally, I wouldn't give the CMC the time of day when the GFS and Euro are far different due to its inferiority and tendency to show false TC's. Therefore, I rarely post CMC maps and I'm not one to hype the tropics without a sound meteorological reason. Furthermore, I'm still not betting on it scoring a coup as of now. However, and this is a big however, the MJO is now getting close to an amplitude of 2.00 in phase 1 and rising further. If the Euro and GFS ensemble mean MJO forecasts were to verify, it would peak near 2.30 in phase 1 ~9/1-2, which is consistent with what the Euro has been showing for days. A 2.30 amplitude MJO in phase 1 would be the 2nd strongest MJO in either phase 1 or phase 2 near the peak of the season (8/21-9/20) since at least 1975! It would just beat the 9/5/81 peak of 2.21. Here are the two strongest as of now and the TC geneses while the MJO was 1.50+ in phase 1 or 2 just for the storms that eventually became hurricanes:

 

-3.08 peak 8/28/79: cat 5 David, cat. 4 Frederic, cat 2 Gloria

-2.21 peak 9/5/81: cat 1 Emily, cat 3 Floyd, cat 2 Gert

 

 Actually, a whopping six total TC's formed during the strong 1979 MJO!

 

 So, I'm wondering if it is possible that the Euro and GFS are not responding enough to this strong phase 1 MJO being that we're looking at about a one in 15 or so year event near the season's peak. Could it be that the CMC is responding more appropriately?

 

Any opinions?

 

 

 

 

 

00z GFS does have a 200mb anticyclonic circulation north of PR on Day 5 that moves over Cuba Day 7-8 then into the Yucatan  D10. There is a hint of a surface troff the the northeast of it. Draw your own conclusions.

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You can always play the "remember when" game and look at old icyclone videos.

 

:D

 

P.S.  In case anyone wants to play that game:  http://www.youtube.com/cyclonejosh

 

That icyclone guy hasn't produced any new videos in years.  Wonder why ...  :whistle:

 

:P

 

C'mon-- I produced a couple last year.  I did what I could with what I had.  Ernesto was actually kinda dramatic:

 

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Peak of the season approaching, and except for the Canadian, all is quiet on the horizon.

 

Mildly depressing.

 

Wondering what the mini-blob du jour off Alabama is.  Looks like an MCS that made it to water.  CIMSS analysis doesn't show appreciable vorticity at any level.  If there was vorticity anywhere, it is under reasonable shear and divergence aloft (which I guess is driving the storms).  SPC mesoanalysis seems to suggest it is in good 2.3" PW air, but very dry air is nearby.  LIX was 1.46" at 0Z  Fun to look at, but I suspect it dies soon, and it has no model attention that it even exists, let alone support to develop.

 

 

I just woke up and decided to see if the Euro had anything anywhere.  Back to bed.

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