Atlantic Tropical Action 2013

[hurricaneman]

I haven't read anything specific about the significance of temperatures at the 400 mb height level. The temperature 

profile is one that you would expect to see in an Atlantic tripole pattern. All those analogs were the result of a strong -AO/NAO winter pattern.

 

 

Dr. Masters had a great post on this pattern back in 2010.

 

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=1444&tstamp=

FEB.png

 

Its quite scary looking at such analogs as 1969, 2004, 2005. That really is something to watch especially if you live on the Gulf Coast or Florida, and unfortunately fit my analog years close to what that video with Levi Cowen mentioning it as a possibility and Joe Bastardi using them as his main analog years, but the one thing that needs to be watched is whether or not the instability stays below normal and causes there to be less intensity to the storms or if the instability comes up and causes a possible major problem for the Southeast coast to the Gulf, basically we will find out by June which way its going to go instability wise

[bluewave]

Its quite scary looking at such analogs as 1969, 2004, 2005. That really is something to watch especially if you live on the Gulf Coast or Florida, and unfortunately fit my analog years close to what that video with Levi Cowen mentioning it as a possibility and Joe Bastardi using them as his main analog years, but the one thing that needs to be watched is whether or not the instability stays below normal and causes there to be less intensity to the storms or if the instability comes up and causes a possible major problem for the Southeast coast to the Gulf, basically we will find out by June which way its going to go instability wise

 

It will be interesting to see if we continue with the instability below normal this season like the last several ones. 

The last few seasons show that you can get major to historic impacts from category 1 hurricanes. The three hurricane

landfalls were similar in that they were large category 1 hurricanes with pressures usually associated with storms in

a higher category. In 2010 we also saw Alex have the lower pressure to wind relationship then you would expect

with Earl and Igor maintaining very low pressures into their later stages.

 

2012...Sandy....940...1

2012...Isaac.....966....1

2011...Irene.....952.....1

2010...Alex.......948......2

2010...Earl.......961......TS

2010...Igor.......945.....1

[am19psu]

New NHC verification is out on the main NHC page. I tweeted a bunch of stuff about it today.

[CoastalWx]

GFS ( in general)  has been much better with tropicals.

[Ed Lizard]

Nothing against people in Florida, but 2004 was a good year to be an internet tropical weather fan, and they haven't had any red meat action in years.

 

So, the more 2004 analogs, the better...

 

Plus they have building codes and a well trained populace.

[Ed Lizard]

 

http://www.weatherbell.com/2013-Hurricane-Season-Forecast

 

 

I suppose almost any tropical cyclone hitting the NYC or SNE subforums would produce much higher than normal ACE in those areas, and JB may not be calling for 1938 redux, but still.  As weenie as I am, I kind of hope they get a year off. 

[OKpowdah]

I suppose almost any tropical cyclone hitting the NYC or SNE subforums would produce much higher than normal ACE in those areas, and JB may not be calling for 1938 redux, but still.  As weenie as I am, I kind of hope they get a year off. 

 

Odd graphic IMO. 1) is it an ACE anomaly or total ACE? 2) Basically outlines climatology aside from nixing the western Gulf and adding some to the EC.

 

And as far as I know, spacial distributions of ACE aren't really common products. I mean, I like the idea, but I think some heavy reanalysis and publicizing needs to be done before that actually becomes a useful forecast graphic

[Ed Lizard]

Odd graphic IMO. 1) is it an ACE anomaly or total ACE? 2) Basically outlines climatology aside from nixing the western Gulf and adding some to the EC.

 

And as far as I know, spacial distributions of ACE aren't really common products. I mean, I like the idea, but I think some heavy reanalysis and publicizing needs to be done before that actually becomes a useful forecast graphic

 

 

I suppose one could divide up the basin into small sections, and then get an average of the annual ACE from every storm whose RMW crosses the section per six hour period or something.  I doubt WeatherBell did that...  My first thought was Weenie bait.

[TropicalAnalystwx13]

The NAO is quickly becoming positive and is forecast to remain at least slightly positive for much of April. Accordingly, sea surface temperature anomalies in the Main Development Region--which were over 1.2C a few days ago--have began to fall. At this length of time, it probably won't deter the forecasts of an extremely active season, but we'll have to see if it persists. If it does, then there will probably be implications.

[HM]

Florida may or may not get hit this year; but overall, I think 2004 will not hold up as an analog this summer/tropical season.

The globe during 2002-03 to 2005-06 sort of went off the rails, in terms of long term progression of various oceanic indices. The underwater currents during this time basically slowed down to the point where the Atlantic overturning current stopped for a few days in November of 2004. As for its effect on the Pacific, the PDO went positive and La Niña basically had little to no presence. The combination of the Pacific shift and warm Atlantic allowed for circulation to favor Florida and an active tropical season.

I need a better reason than the QBO to use 2004 as an analog (by the way, I'm not saying the QBO or 2004 has no use in helping you forecast this season or any season).

[bluewave]

Florida may or may not get hit this year; but overall, I think 2004 will not hold up as an analog this summer/tropical season.

The globe during 2002-03 to 2005-06 sort of went off the rails, in terms of long term progression of various oceanic indices. The underwater currents during this time basically slowed down to the point where the Atlantic overturning current stopped for a few days in November of 2004. As for its effect on the Pacific, the PDO went positive and La Niña basically had little to no presence. The combination of the Pacific shift and warm Atlantic allowed for circulation to favor Florida and an active tropical season.

I need a better reason than the QBO to use 2004 as an analog (by the way, I'm not saying the QBO or 2004 has no use in helping you forecast this season or any season).

 

The post 2005 ACE has really shown the differences.

 

[TropicalAnalystwx13]

The NAO is quickly becoming positive and is forecast to remain at least slightly positive for much of April. Accordingly, sea surface temperature anomalies in the Main Development Region--which were over 1.2C a few days ago--have began to fall. At this length of time, it probably won't deter the forecasts of an extremely active season, but we'll have to see if it persists. If it does, then there will probably be implications.

[to further expand]

 

...of course, if the dipole shifts far enough north, it doesn't really matter.

 

[HM]

The post 2005 ACE has really shown the differences.

Yes indeed and it is likely to remain the peak period. Now, if we suddenly went into an El Niño/+PDO type of environment for a few years that efffectively slows the currents down during the remaining +AMO period to come, it is possible we see a secondary ACE maximum then.

This year could head in that direction easily and kick it off; it is not too late.

[bluewave]

Yes indeed and it is likely to remain the peak period. Now, if we suddenly went into an El Niño/+PDO type of environment for a few years that efffectively slows the currents down during the remaining +AMO period to come, it is possible we see a secondary ACE maximum then.

This year could head in that direction easily and kick it off; it is not too late.

 

True, we would just need see the instability return to more normal levels with less drying than the last few seasons 

for the ACE move toward another peak.

 

Each season is a new learning experience.

[OKpowdah]

CDF and PDF for ASO ACE by MQI phase. Can see the distribution of monthly ACE anomaly percentiles for each MQI phase. 

 

For example, phases -180 to -120 (descending easterlies / easterly shear regime) lean heavily below normal

 

 

[HM]

Sam, thanks for the information. You are projecting a 60 to possibly a 90 MQI phase for ASO, correct? This would be a little behind 2004 and a little ahead of 2006. Looks like 2008, 1997 (lol), 1990 and 1980 are some of the better MQI progressions since 1979.

[Ground Scouring]

True, we would just need see the instability return to more normal levels with less drying than the last few seasons 

for the ACE move toward another peak.

 

Each season is a new learning experience.

Precip.png

HM, what are your thoughts re: why instability has been generally reduced since 2005, and especially since 2008, in the Atlantic? Is it related to the Arctic ozone layer and reduced summertime ice pack recently?

 

I would very much appreciate your input.

[bluewave]

HM, what are your thoughts re: why instability has been generally reduced since 2005, and especially since 2008, in the Atlantic? Is it related to the Arctic ozone layer and reduced summertime ice pack recently?

 

I would very much appreciate your input.

 

There has been research into a process called the upped-ante mechanism which would result in lower atmospheric

instability in the tropics. But I haven't seen any studies yet specifically implicating this in the recent hurricane seasons.

David Neelin at UCLA seems to be the main expert in this field of study.

[Ground Scouring]

There has been research into a process called the upped-ante mechanism which would result in lower atmospheric

instability in the tropics. But I haven't seen any studies yet specifically implicating this in the recent hurricane seasons.

David Neelin at UCLA seems to be the main expert in this field of study.

http://www.atmos.ucla.edu/~csi/RESEARCH/uppedante.html\

 

This is interesting as the sea-level pressures in the tropical Atlantic have actually been quite below average in 2010-2012. So climate change would seem to have at least some effect combined with other factors favoring less instability. Could this reduced instability in the tropics be shifting the development farther N, as in 2012 with so much genesis N of the MDR?

[bluewave]

http://www.atmos.ucla.edu/~csi/RESEARCH/uppedante.html\

 

This is interesting as the sea-level pressures in the tropical Atlantic have actually been quite below average in 2010-2012. So climate change would seem to have at least some effect combined with other factors favoring less instability. Could this reduced instability in the tropics be shifting the development farther N, as in 2012 with so much genesis N of the MDR?

 

I have read that they will have to do higher resolution model studies to accurately simulate how a hurricane would respond to those

potential changes to get that kind of detailed information.

[AvantHiatus]

Tropical Atlantic sea surface temperature anomalies have crash dived over the past week. However, they were already quite high nearing 1 C above average in Late March. Somewhat surprising considering the NAO state, there must be other processes at work and mabye some prolonged cloudiness preventing decent solar radiation from reaching the ocean surface.

 

[icebreaker5221]

http://www.atmos.ucla.edu/~csi/RESEARCH/uppedante.html\

 

This is interesting as the sea-level pressures in the tropical Atlantic have actually been quite below average in 2010-2012. So climate change would seem to have at least some effect combined with other factors favoring less instability. Could this reduced instability in the tropics be shifting the development farther N, as in 2012 with so much genesis N of the MDR?

 

 

It has been an interesting trend recently, but I wouldn't be too quick to generalize like that.  Three years of below average instability in the MDR does not yet make a trend on climate time scale.  Also, I see no reason for climate change to favor reduced instability in the Atlantic while the other basins have not been experiencing the same trend. 

[bluewave]

A very talented local Long Beach photographer documented her experience with Hurricane Sandy

from her home near Lincoln Blvd and East Broadway in Long Beach.

 

[TropicalAnalystwx13]

MDR sea surface temperature anomalies have taken a big hit over the past week or so...and in fact, cooler than average values are beginning to show up in the extreme eastern Atlantic. This is attributed to increased trade winds due to increased high pressure in the central Atlantic (though not a result of the NAO, it's still negative interestingly enough). We may see some more cooling over the next week, but by weeks 2-4, the CFS forecasts below average trade winds and subsequent warming once again.

 

 

Also interesting is the rapid deterioration of the PDO. Significant warming of SSTs has occurred just off the West Coast, while the region where high pressure usually sits has cooled. Classic signature of a positive. I really don't have any idea why it flipped so suddenly...but the GEFS forecast a return to high pressure over the next week or so, continuing throughout the period, so the negative PDO signature should come back.

 

[Ed Lizard]

I was not aware how much variation there was within the broader PDO...

 

 

[MJO812]

TWC just issued their outlook. They are calling for an active season.

 

http://www.weather.com/news/weather-hurricanes/hurricane-season-outlook-april-20130408

[icebreaker5221]

Wow, there hasn't been this good a consensus for an above-normal season since 2006!

[Eyewall2005]

Wow, there hasn't been this good a consensus for an above-normal season since 2006!

 

Whats your take on upcoming season? Hoping other pro-mets will start to chip in on how the season is shaping up as we get closer to june.

[Ed Lizard]

Klotzbach outlook comes Wednesday, I think.

[MJO812]

Here is a 2013 hurricane outlook from  Weatherundergroud.com

 

http://www.wunderground.com/blog/HurricaneDean07/comment.html?entrynum=39