Atlantic Tropical Action 2014

[Srain]

The 12Z run of the European model certainly agrees with the idea of a pattern that features large high pressure over the northeast United States leading to potential tropical development over the Gulf of Mexico.  

 

get_orig_img.png

The area develops slowly in the NW Caribbean later this coming week and drifts slowly NW across the Yucatan and enters the Western Gulf next weekend. The ensembles have been rather suggestive in lowering pressures across SW Caribbean into the Western Gulf and a frontal boundary is expected to stall across the NW/Central Gulf Coast Tuesday of next week.

[bluewave]

Edouard boosted the Atlantic ACE from 20 to 35.95 which is just about tied with the 36 total from 2013.

[Kory]

The Euro is showing a low pressure forming on the tail end of a front in the Gulf this weekend. It has it quickly moving north into Louisiana. Should bring some heavy rain to the Gulf Coast. The GFS on the other hand just shows an inverted trough.

[bluewave]

The expansive area of dry midlevel over the Tropical Atlantic set a new record for JJA 2014.

Most of the ACE was located north of 25N where less hostile conditions for development

were found. The last Tropical Atlantic major hurricanes were Igor and Julia in 2010.

 

 

 

[GaWx]

Bluewave,

Do you think that reanalysis graph is accurate? If so, holy multidecadal drying trend!! If accurate, what are the likely causes?

[bluewave]

Bluewave,

Do you think that reanalysis graph is accurate? If so, holy multidecadal drying trend!! If accurate, what are the likely causes?

 

Klotzbach says that the record is reliable going back to 1970. So I am not sure about the portion of the plot

during the 1950's and 1960's. My guess is that the cause is related to the widening Hadley circulation.

I found a recent paper on the changes, but it would be good to see a paper focusing on the Atlantic.

 

 

Role of changes in mean temperatures vs. temperature gradients in the recent widening of the Hadley circulation

 

http://www.oriadam.info/oriadam/HCW_Expansion_2014.pdf

 

From last year:

 

http://www.climatecentral.org/news/what-happened-to-the-2013-atlantic-hurricane-season-16616

 

 

Some of the dry air across the Atlantic Basin came from large areas of dusty air that originated in the scorching Sahara Desert. However, such outbreaks of dusty air are fairly typical during hurricane season. What has been unusual has been the broad expanse of sinking and drying air throughout the North Atlantic basin, McNoldy said.

This season, the dry air “made a huge difference” and “squashed all the other factors that looked good,” he said.

Klotzbach said the area where most tropical storms and hurricanes form had the driest mid-to-lower atmospheric conditions during the Aug. 1 to Sept. 25 period since reliable records began in 1970.

[hurricaneman]

Wouldn't surprise me if 1913-1915, 1968-1970, and 1990-1994 had similar or even drier conditions in the MDR and if dry MDR periods happened in 3 year spurts on average then maybe we are coming out of such a pattern within 3 years or if the 3 year pattern is true maybe next year but its just one of many factors that make a hurricane season

[andyhb]

Wouldn't surprise me if 1913-1915, 1968-1970, and 1990-1994 had similar or even drier conditions in the MDR and if dry MDR periods happened in 3 year spurts on average then maybe we are coming out of such a pattern within 3 years or if the 3 year pattern is true maybe next year but its just one of many factors that make a hurricane season

 

The graph would indicate otherwise.

[hurricaneman]

The graph would indicate otherwise.

well maybe the 1913-1915 period but what I forgot to add is that it seems to be that once a decade the widening Hadley Circulation causes dry stable air to come into the MDR and shut that area down pretty much plus the one thing I do notice is that it happens every 7 to 10 years so that may need to be looked at more when forecasting a hurricane season

[Amped]

Looks pretty dead for the fordable future.

[PSUBlizzicane2007]

Yeah too bad that cyclone in the gulf that the Euro was showing isn't going to happen. It was probably our only shot at a decent homebrew this year.

[Roger Smith]

A reminder to contest entrants to post your October monthly forecast before 06z Oct 1.

 

Seasonal forecasts cannot be amended (sigh).

 

In the thread I will update the scoring in a day or two if it appears likely that we are stuck at 2/1/1 for September. It will be ugly.

[wxmx]

From the lemon in the Atlantic (which is not expected to develop further)

 

[wxmx]

I think this low in the central Atlantic deserves a little more attention. It's currently in a very tight shear gradient area, where 50 miles make a lot of difference. 50 miles to the northwest there's >20kts of shear...while 50 miles to the southeast it's around 10 kts. It's currently consolidating a bit further south than forecasted, that's the reason it's blooming with convection right now.

 

Shear is not going anywhere, though, so I don't expect much development once it starts gaining longitude, but at least it has some potential for namewaster.

[thetonynator]

Exactly half the number of named storms as this time last year - exciting season!!!

[Kory]

http://www.sun-sentinel.com/local/broward/fl-hurricane-intensity-era-20140924,0,1433898.story

 

Is the multi-decadal active period in the Atlantic ending?  I personally think no, as it's very common to have down years in long term periods of increased activity.  The AMO oscillates every 20-40 years.  We're about 15-20 years in currently.  What are y'all's thoughts on this article?

 

[GaWx]

http://www.sun-sentinel.com/local/broward/fl-hurricane-intensity-era-20140924,0,1433898.story

Is the multi-decadal active period in the Atlantic ending? I personally think no, as it's very common to have down years in long term periods of increased activity. The AMO oscillates every 20-40 years. We're about 15-20 years in currently. What are y'all's thoughts on this article?

Kory,

Well, the 1890-1900ish active period was only ~17 years. Why can't this one be of similar length?

[icebreaker5221]

http://www.sun-sentinel.com/local/broward/fl-hurricane-intensity-era-20140924,0,1433898.story

 

Is the multi-decadal active period in the Atlantic ending?  I personally think no, as it's very common to have down years in long term periods of increased activity.  The AMO oscillates every 20-40 years.  We're about 15-20 years in currently.  What are y'all's thoughts on this article?

 

We could be at the tail end of a shorter +AMO cycle, a la late 1800s; or it's also just as possible that we've reached a temporary lull in the midst of a longer +AMO similar to the dip in the late 40s.  If we go 2 or 3 more years without an uptick, it becomes increasingly likely that we've made the flip to negative.  As of right now, with the data at hand, it's probably too soon to say. 

[GaWx]

Fwiw and only for the record and entertainment for now since it has had a lot of false alarms in the Gulf and Caribbean this season: Similar to what it showed at least once on Thursday and I think at least 12z on Friday, all four GFS runs today showed SW Caribbean genesis ~10/9-10 as well as subsequent development and movement northward. The last two runs come near or hit S FL ~10/13-4 with a 'cane as it moves northward.

MJO: projected to be within circle per Euro ens. for next two weeks, which has been neutral for genesis chances in Oct. since 1995 with development about once every ten days on average while within the circle.

Edit: Not surprisingly, the GEFS have been in support all day while the Euro ens./CDN ens. have shown next to nothing from what I see.

[hurricaneman]

The GFS has come back to having a possible hurricane in the Caribbean moving towards Florida but it seems like development in the Caribbean might be becoming more possible with the Euro starting to lower pressures in the Caribbean around 144hrs and by the end of its run starts to develop something

[GaWx]

Fwiw and only for the record and entertainment for now since it has had a lot of false alarms in the Gulf and Caribbean this season: Similar to what it showed at least once on Thursday and I think at least 12z on Friday, all four GFS runs today showed SW Caribbean genesis ~10/9-10 as well as subsequent development and movement northward. The last two runs come near or hit S FL ~10/13-4 with a 'cane as it moves northward.

MJO: projected to be within circle per Euro ens. for next two weeks, which has been neutral for genesis chances in Oct. since 1995 with development about once every ten days on average while within the circle.

Edit: Not surprisingly, the GEFS have been in support all day while the Euro ens./CDN ens. have shown next to nothing from what I see.

 

 Fwiw (mainly entertainment but I also like to get these detailed posts in here for the record in case people want to look back), the GFS does have the W. Caribbean development again ~10/10 on today's 12Z run along with an approach to SE FL on 10/16. It has, of course, been horrible with numerous Gulf and Caribbean false alarms this season. Also, even the development ~10/10 on this run is still pretty far out in time. Furthermore, it has it hitting FL on 10/16. This is delayed from the Sunday runs that had it hit/near S FL on 10/13-4 and another reason to take this with a humongous grain of salt. Moreover, it had next to nothing on the prior six runs. Finally, I still see no clearcut Euro support for an organized surface low forming down in the SW Caribbean around the end of its run (10/10).

 

Edit: 18Z GFS: back to nada.

[Kory]

 Fwiw (mainly entertainment but I also like to get these detailed posts in here for the record in case people want to look back), the GFS does have the W. Caribbean development again ~10/10 on today's 12Z run along with an approach to SE FL on 10/16. It has, of course, been horrible with numerous Gulf and Caribbean false alarms this season. Also, even the development ~10/10 on this run is still pretty far out in time. Furthermore, it has it hitting FL on 10/16. This is delayed from the Sunday runs that had it hit/near S FL on 10/13-4 and another reason to take this with a humongous grain of salt. Moreover, it had next to nothing on the prior six runs. Finally, I still see no clearcut Euro support for an organized surface low forming down in the SW Caribbean around the end of its run (10/10).

 

Edit: 18Z GFS: back to nada.

I'm starting to think this season is over as far as mainland U.S.  There's several big fronts forecasted to move through and ensembles for the first 2 weeks in October feature major troughing along the East Coast.  Perhaps we'll get one more storm (not affecting the U.S.) before it's all over with...if not, 5 storm season is gotta be the quietest we've been in a long time.  

[Max]

Pretty sure there is a TC out there in the North Atlantic. Has sustained convection for quite some time and it's somewhat covering the COC even though it is getting sheared.

[GaWx]

 Fwiw (mainly entertainment but I also like to get these detailed posts in here for the record in case people want to look back), the GFS does have the W. Caribbean development again ~10/10 on today's 12Z run along with an approach to SE FL on 10/16. It has, of course, been horrible with numerous Gulf and Caribbean false alarms this season. Also, even the development ~10/10 on this run is still pretty far out in time. Furthermore, it has it hitting FL on 10/16. This is delayed from the Sunday runs that had it hit/near S FL on 10/13-4 and another reason to take this with a humongous grain of salt. Moreover, it had next to nothing on the prior six runs. Finally, I still see no clearcut Euro support for an organized surface low forming down in the SW Caribbean around the end of its run (10/10).

 

Edit: 18Z GFS: back to nada.

 

For the record and entertainment:

1) The 0Z GFS had nada just like yesterday's 18Z.

2) The 6Z GFS had a weak low form in the SW Caribbean 10/10 and then a piece of that energy quickly moved to FL 10/14 (weak low) while leaving the other piece in the NW Caribbean for the rest of the run (another weak low).

3) The 12Z GFS has a low form ~10/11 in the SW Caribbean that becomes a hurricane ~10/14 and only moves very slowly NW to just south of western Cuba 10/17 (end of run). So, compared to the Sunday GFS runs that showed something, the TC on this run is a good 4-6 days behind on movement (not genesis) based on it still being in the NW Caribbean on 10/17. This among other things is a reason to give very low credibility to this run.

 Bottom line: I continue to take these GFS runs with a gigantic grain of salt for obvious reasons including no Euro support and timing delays in the modeled movement. If some runs still show something, say, about 4-5 days from now, I'd take then a little more seriously, especially if the Euro changes and gives some support. However, the smart money is still very likely on these being more phantom storm runs.

 

[icebreaker5221]

Pretty sure there is a TC out there in the North Atlantic. Has sustained convection for quite some time and it's somewhat covering the COC even though it is getting sheared.

 

I suppose a case could be made.  Models appear to be initializing it as marginally warm core as well.  Circulation centers definitely not aligned - par for the course 2014. 

 

 

[Juliancolton]

Maybe the NHC will throw us a bone and give us a post-season inclusion as a consolation prize.

 

[Wannabehippie]

I suppose a case could be made.  Models appear to be initializing it as marginally warm core as well.  Circulation centers definitely not aligned - par for the course 2014. 

 

 

GOES173020142749GYNH2.jpg

Maybe a sub-tropical low?

[GaWx]

For the record and entertainment:

1) The 0Z GFS had nada just like yesterday's 18Z.

2) The 6Z GFS had a weak low form in the SW Caribbean 10/10 and then a piece of that energy quickly moved to FL 10/14 (weak low) while leaving the other piece in the NW Caribbean for the rest of the run (another weak low).

3) The 12Z GFS has a low form ~10/11 in the SW Caribbean that becomes a hurricane ~10/14 and only moves very slowly NW to just south of western Cuba 10/17 (end of run). So, compared to the Sunday GFS runs that showed something, the TC on this run is a good 4-6 days behind on movement (not genesis) based on it still being in the NW Caribbean on 10/17. This among other things is a reason to give very low credibility to this run.

 Bottom line: I continue to take these GFS runs with a gigantic grain of salt for obvious reasons including no Euro support and timing delays in the modeled movement. If some runs still show something, say, about 4-5 days from now, I'd take then a little more seriously, especially if the Euro changes and gives some support. However, the smart money is still very likely on these being more phantom storm runs.

 

 

Following up, today's 0Z/6Z/12Z GFS and 0Z/12Z Euro all essentially had nada. However, for entertainment/record keeping, the 18Z of the newly designated Crazy Uncle is back to a 10/10 genesis of a TC in the SW Caribbean. This time, it hauls it off much more quickly, further west vs. prior runs to just north of the tip of the Yucatan on 10/15, and then accelerates it NNEward as a TS to a hit on the FL Big Bend early on 10/16 at 996 mb. This is then followed by it rocketing up the eastern seaboard 10/16-7. All fwiw, especially considering inconsistency on genesis.

[GaWx]

Following up, today's 0Z/6Z/12Z GFS and 0Z/12Z Euro all essentially had nada. However, for entertainment/record keeping, the 18Z of the newly designated Crazy Uncle is back to a 10/10 genesis of a TC in the SW Caribbean. This time, it hauls it off much more quickly, further west vs. prior runs to just north of the tip of the Yucatan on 10/15, and then accelerates it NNEward as a TS to a hit on the FL Big Bend early on 10/16 at 996 mb. This is then followed by it rocketing up the eastern seaboard 10/16-7. All fwiw, especially considering inconsistency on genesis.

 

 It is getting a little more interesting today. Today's 12Z GFS is the 4th in a row showing a TC genesis ~10/10 in the SW Caribbean (also, similar timing vs. those runs from five days back fwiw...i.e., it hasn't slipped back) and impacting somewhere within the central to NE Gulf coast  10/16 before rocketing NNE to the NE US on 10/17. This is quite consistent timing. Although this is still in the "for mainly entertainment" category, that assessment could start to change pretty signficantly in my mind if, say, the GFS runs on Sunday continue to show ~10/10 SW Caribbean genesis as well as a US Gulf hit ~10/16 and especially if the Euro starts supporting this. We'll see.

 

Edit: MJO is projected to remain within the circle per the Euro ensemble mean. That is pretty much a neutral indicator per Oct. genesis stats since 1995 (~10% chance for development on any single day, which means ~50% chance for genesis over about a six day period)

[thewxmann]

 It is getting a little more interesting today. Today's 12Z GFS is the 4th in a row showing a TC genesis ~10/10 in the SW Caribbean (also, similar timing vs. those runs from five days back fwiw...i.e., it hasn't slipped back) and impacting somewhere within the central to NE Gulf coast  10/16 before rocketing NNE to the NE US on 10/17. This is quite consistent timing. Although this is still in the for mainly entertainment category, that assessment could start to change pretty signficantly in my mind if, say, the GFS runs on Sunday continue to show ~10/10 SW Caribbean genesis as well as a US Gulf hit ~10/16 and especially if the Euro starts supporting this. We'll see.

 

If anything happens in the SW Caribbean for the rest of this year, I will eat my shoe.