Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Atlantic Tropical Action 2011 - Part III


Recommended Posts

Alright, I'm done. This stupid season is the worst I have ever seen, and these models sure aren't helping. Run after run of the GFS finally consistently shows a strong system, and now what does the Euro do? Of course it loses it. Now the 18z GFS will probably lose it as well. Maybe we won't get a hurricane this season after all.

LOL, the 12z Euro has at least 4 TC's modeled, we are up to the G storm in mid-August (yeah, a little light on the intensity side), and there are certainly lots of decent signals that the rest of the season will be exciting......"Calm down, Beavis!!"

Link to comment
Share on other sites

  • Replies 1k
  • Created
  • Last Reply

Alright, I'm done. This stupid season is the worst I have ever seen, and these models sure aren't helping. Run after run of the GFS finally consistently shows a strong system, and now what does the Euro do? Of course it loses it. Now the 18z GFS will probably lose it as well. Maybe we won't get a hurricane this season after all.

Its over 240 hours, what did you expect? Its fantasy land man... take any run (even if its consistent) with a grain of salt... probably greater than 120 hours. If you are thinking we may not get a hurricane at all this season, that is downright silly. We are typically near the time when we finally start getting active. We're really not that far behind if at all.

Link to comment
Share on other sites

It wouldn't be a threat to land other then maybe Bermuda LEK, so no doubt it'd get totally ignored by most in favour of the puch 17l which could be a threat...

Suspect that would take the classic WNW till 60W then up and out type track....but I get ya point :P

Link to comment
Share on other sites

The MJO looks to be favorable now that we're heading into peak hurricane season. Phases 1 and 2 or the MJo are the active phases. Forecasts are for the MJO to be in the favorable phases.

post-70-0-71346600-1313522690.gif

It certainly is not a time to lose hope. The Sahara dust still is a player but....this is the time of year when the season really starts to ramp up.

Link to comment
Share on other sites

The MJO looks to be favorable now that we're heading into peak hurricane season. Phases 1 and 2 or the MJo are the active phases. Forecasts are for the MJO to be in the favorable phases.

post-70-0-71346600-1313522690.gif

It certainly is not a time to lose hope. The Sahara dust still is a player but....this is the time of year when the season really starts to ramp up.

Which I often wonder if it doesn't help increase LF chances out this way,wrt CV storms if SAL remains predominately where it has been this season. (Keeping any TC's from intensifying too much and getting the inevitable poleward tug.....

Link to comment
Share on other sites

I'm not getting down yet. Suggestion of some support for something near Florida in 10 days as shown on the GFS, with 3 ensemble members having sub 1004 mb lows in the general area, the Euro not too different, and a pattern that might take a storm at least close to Florida.

post-138-0-26953800-1313523648.gif

Link to comment
Share on other sites

Which I often wonder if it doesn't help increase LF chances out this way,wrt CV storms if SAL remains predominately where it has been this season. (Keeping any TC's from intensifying too much and getting the inevitable poleward tug.....

I don't think its the dust itself, more so the airmass that accompanies the dust, that supresses development.

Link to comment
Share on other sites

I know it's basically voodoo land to be looking past 120 hours, but it's interesting to see what possibilities are out there. Here is the latest GFS. Shows a good storm heading for the northern to northeast Gulf coast???

gfs_namer_288_1000_500_thick.gif

Posting a GFS map 12 days out is kind of frowned upon here... just a little heads-up. :)

And welcome to the board.

Link to comment
Share on other sites

I don't think its the dust itself, more so the airmass that accompanies the dust, that supresses development.

From what I recall reading about this, it is both. As you're suggesting, the dry air that often accompanies the dust tends to be a deterrent. In addition, the dust, itself, is not as conducive as other particles to forming rain droplets because they tend to repel moisture. Also, because the dust particles are so numerous, the individual particles are often unable to acquire enough moisture to make a rain droplet.

Link to comment
Share on other sites

I don't think its the dust itself, more so the airmass that accompanies the dust, that supresses development.

I'm definitely not an aerosol/microphysics expert at all, but from some of the papers I've read about the SAL and TCs, the dust part of the equation is a lot more uncertain than the dry air part. There have even been some papers suggesting that the dust actually is a positive influence.

The other thing I want to mention is that not all of the dry air in the Central/Eastern Atlantic is necessarily SAL. Often times much of it is actually due to large-scale subsidence. One sure-fire way to diagnose the presence of SAL is to actually have a sounding that has a strong mid-level easterly jet and very dry air in the mid-levels. Perhaps another way is to calculate backward trajectories that shows the air originating from the Saharan region.

Link to comment
Share on other sites

I'm definitely not an aerosol/microphysics expert at all, but from some of the papers I've read about the SAL and TCs, the dust part of the equation is a lot more uncertain than the dry air part. There have even been some papers suggesting that the dust actually is a positive influence.

The other thing I want to mention is that not all of the dry air in the Central/Eastern Atlantic is necessarily SAL. Often times much of it is actually due to large-scale subsidence. One sure-fire way to diagnose the presence of SAL is to actually have a sounding that has a strong mid-level easterly jet and very dry air in the mid-levels. Perhaps another way is to calculate backward trajectories that shows the air originating from the Saharan region.

Don't you need dust in the atmosphere to create rain?

Link to comment
Share on other sites

Don't you need dust in the atmosphere to create rain?

Yes, though the impact of dust on TC convection is unclear. Overall I think the SAL, if it gets entrained into the TC core, is a negative influence because the dry-air impacts probably overwhelm the microphysical impacts of the dust.

Link to comment
Share on other sites

Don't you need dust in the atmosphere to create rain?

I'm not sure the research is at a point where we can say without a doubt that it is a plus/minus to development from a microphysical standpoint...Yes, dust is a good CCN, but if you have too many CCNs you have too many small droplets, a scenario which doesn't lend itself to efficient precipitation development.

Also, studies have shown that dust can have a large enough radiative effect leading to cooler SSTs in the equatorial Atlantic, during particularly dry years in the Sahel region of Africa.

Link to comment
Share on other sites

Yes, though the impact of dust on TC convection is unclear. Overall I think the SAL, if it gets entrained into the TC core, is a negative influence because the dry-air impacts probably overwhelm the microphysical impacts of the dust.

Was wondering knowing that most TC's usually are not in heavy development stage out that way really (Central/Eastern Atlantic), so if the dust itself were to have an impact on genisis/rapid development the system would have tp be less developed? I find it difficult to determine since Dry air and african dust usually go hand in hand. The positive effects of dust, if any, would need to come earlier in the development stage?

I am taking particle physics, obviously haven't gotten into this yet, and you know much more than I do here. I've just never found reason to presume dust itself as a deterent since it is known to be a positive influence in rainfall.

Link to comment
Share on other sites

Was wondering knowing that most TC's usually are not in heavy development stage out that way really (Central/Eastern Atlantic), so if the dust itself were to have an impact on genisis/rapid development the system would have tp be less developed? I find it difficult to determine since Dry air and african dust usually go hand in hand. The positive effects of dust, if any, would need to come earlier in the development stage?

I am taking particle physics, obviously haven't gotten into this yet, and you know much more than I do here. I've just never found reason to presume dust itself as a deterent since it is known to be a positive influence in rainfall.

See...

http://www.ldeo.columbia.edu/~bc9z/mypubs/2008_hui.pdf

Dust can be a deterrent to rainfall.

Essentially, the large number of CCNs leads to an overpopulation of small droplets which are not efficient at the collision/coalescence process which leads to larger cloud droplets and eventually rainfall.

Link to comment
Share on other sites

See...

http://www.ldeo.colu...bs/2008_hui.pdf

Dust can be a deterrent to rainfall.

Essentially, the large number of CCNs leads to an overpopulation of small droplets which are not efficient at the collision/coalescence process which leads to larger cloud droplets and eventually rainfall.

Wow thanks a bunch, will read it through and through.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...