Global model runs discussion

[South Texas Storms]

18z GFS looks pretty active so far through 141 hours showing possibly 3 developing systems.
http://www.tropicaltidbits.com/analysis ... ics_48.png

[tolakram]

This is the most bullish I have seen the GFS the past several runs showing a monster developing close to Africa and development starts in the 3-4 day timeframe. Here we are at 6 days.

Though my guess is that it won't get alot of attention as it looks like a strong fish candidate developing that far east:

http://img833.imageshack.us/img833/9291/wh84.png

That's 6 runs in a row now for this wave. Might be 7, I lost count. Hour 105 now, so it's not one of those delayed development types the GFS likes to produce.

[Alyono]

Read more, post less. For clarification, subtropical development north of 30 has NOTHING to do with the MDR.

Upward velocities look good WEST of 50 W. Most models are even showing some tropical waves surviving past 50 West which is a noticeable change from what we have seen.

i read what alyono said about the upward velociteies not making it to the atlantic for the next 16 days. anytime you have subtropical development north of 30, thats not a good sign for the MDR.

maybe just read and not post for ninel. I really do not appreciate having someone like ninel putting words in my mouth

[Alyono]

This is the most bullish I have seen the GFS the past several runs showing a monster developing close to Africa and development starts in the 3-4 day timeframe. Here we are at 6 days.

Though my guess is that it won't get alot of attention as it looks like a strong fish candidate developing that far east:

http://img833.imageshack.us/img833/9291/wh84.png

That's 6 runs in a row now for this wave. Might be 7, I lost count. Hour 105 now, so it's not one of those delayed development types the GFS likes to produce.

could be one of those monsoon trough parameterization issues though

[cycloneye]

Ok folks,let's not change the topic of this thread to about one person and stick with what the models show in their runs.Thanks for your cooperation.

[ninel conde]

This is the most bullish I have seen the GFS the past several runs showing a monster developing close to Africa and development starts in the 3-4 day timeframe. Here we are at 6 days.

Though my guess is that it won't get alot of attention as it looks like a strong fish candidate developing that far east:

you say a monster. what do the later days show? i agree its likely to recurve should it develop.

[Hammy]

could be one of those monsoon trough parameterization issues though

Would this be similar to the convective feedback issues it was having earlier in the season?

[ninel conde]

http://tropic.ssec.wisc.edu/real-time/i ... 7&prod=irn

i would assume its the wave at 6e 13n that the gfs develops. it does have some appearance of rotation.

[Alyono]

could be one of those monsoon trough parameterization issues though

Would this be similar to the convective feedback issues it was having earlier in the season?

possibly... given how strong it is trying to make it over Cape Verde

[CrazyC83]

This is the most bullish I have seen the GFS the past several runs showing a monster developing close to Africa and development starts in the 3-4 day timeframe. Here we are at 6 days.

Though my guess is that it won't get alot of attention as it looks like a strong fish candidate developing that far east:

you say a monster. what do the later days show? i agree its likely to recurve should it develop.

That trough there? Early recurve probably if that strong right out of Cape Verde. BTW it wouldn't be a fish if it hits CV hard...

[tolakram]

I'm not sure everyone agrees, but the way I see it, regardless of the season, the vast majority of Cape Verde systems will recurve. The chances are too high that they will find an opening.

The increased chance of a Florida and Texas hit, IMO, is due to delayed development and development closer to the Caribbean where a recurve ends up hitting someone. Bad conditions in the tropical Atlantic coupled with good conditions in the Caribbean, Gulf, and east coast favor this scenario.

[TheStormExpert]

Here's a couple of tweets on Twitter by Tropical Tidbit's Levi Cowan:

(@ 9:21pm)
Warm NW Atlantic can lead to ridging - landfalls. Correlation of Aug-Sep SSTs 30N-50N, 75W-40W with Z500 for 1948-2012 is R=0.68, p=3.4e-10

(@ 9:22pm)
The question every year is if storms will form and take advantage of majority ridging, or if they happen to form when troughs can get them.

[ROCK]

https://www.fnmoc.navy.mil/wxmap_cgi/cg ... t=Tropical

18Z NAVGEM....about to get active out there.....though having two system merge like that might be a bit of a stretch.

[meriland23]

GFS really wants to run this way into fish territory.. wonder if that will pan out that way

[SoupBone]

I'm not sure everyone agrees, but the way I see it, regardless of the season, the vast majority of Cape Verde systems will recurve. The chances are too high that they will find an opening.

The increased chance of a Florida and Texas hit, IMO, is due to delayed development and development closer to the Caribbean where a recurve ends up hitting someone. Bad conditions in the tropical Atlantic coupled with good conditions in the Caribbean, Gulf, and east coast favor this scenario.

Isn't this the truth for every CV season though? I thought I read and can't remember where, but 90% of CV storms recurve.

[South Texas Storms]

Tonight's 0z GFS has 2 tropical systems on September 10. One in the GOM and one out in the middle of the Atlantic.
http://www.tropicaltidbits.com/analysis ... ics_76.png

[USTropics]

I'm not sure everyone agrees, but the way I see it, regardless of the season, the vast majority of Cape Verde systems will recurve. The chances are too high that they will find an opening.

The increased chance of a Florida and Texas hit, IMO, is due to delayed development and development closer to the Caribbean where a recurve ends up hitting someone. Bad conditions in the tropical Atlantic coupled with good conditions in the Caribbean, Gulf, and east coast favor this scenario.

Isn't this the truth for every CV season though? I thought I read and can't remember where, but 90% of CV storms recurve.

I think the 90% is a bit confusing. In my research, 90% is referring to the amount of AEWs (African Easterly Waves) that (a) develop into CVSs (Cape Verde Systems), and (b) attain hurricane strength east of 40 degrees longitude. Also I want to clarify, while there is some open opinion about what qualifies as a true CVS, it's generally accepted that any development within 1000 kilometers of the Cape Verde Islands is a CVS.

So let's look at storms that reached hurricane intensity east of 40W and south of 25N. Below is an image:


Remarkably, not a single tropical storm or hurricane has entered the Caribbean after becoming a hurricane that far east, and moreover, only 4 have impacted the United States. Why are CVSs so important than? Of the 5 most notorious systems that have traversed the Atlantic, all 5 have been CVSs.

What we have to worry about are these AEW's moving westward and not developing until they reach 50W/60W. One should keep in mind, on average the Atlantic generates 60 AEWs. These AEWs make up 60% of the Atlantic tropical storms and minor hurricanes, and on a more important note, AEWs contribute to the origins of 85% of the intense (or major) hurricanes in the Atlantic.

In a season like 2005, all the featured systems did not attain hurricane strength until they were west of 60W, much closer to the Caribbean Sea and the United States. That's what Levi Cowan, and to an extent Jeff Masters, have been alluding to. The models not developing these systems right away, until 60W, is not a positive for the Caribbean or United States. Ignoring the specifics of constant models run to run, all have been allluding to increased tropical development in the near future. Furthermore, taking a step back from what the models are showing/not showing, the atmosphere is improving over the next 2 weeks, with anticipation of one of the strongest MJO pulses on record about to enter the Atlantic, at the prime of the season, with decreasing wind shear.

Refrences:
http://www.aoml.noaa.gov/hrd/tcfaq/A4.html
http://en.wikipedia.org/wiki/Cape_Verde-type_hurricane
http://www.sciencedirect.com/science/article/pii/S0169809511000056
http://www.atmo.arizona.edu/students/courselinks/fall11/atmo336/lectures/sec2/hurricanes.html

[meriland23]

I agree with the post right above mine, while CV systems tend to fish more often than the ones that form in the mid-atlantic / Caribbean, they also tend to be the most long lasting and intense storms. It would be foolish to assume any or all storms that form here fish out or will probablyy considering.. like the person said above.. the MJO is stronger this year than usual. The assumption is that CV storms fish out, but there are also typically only 2 CV style hurricanes per season, and models are hinting/suggesting a extremely active season in the CV region with some models suggesting 3-4 systems coming from there within only days of eachother. Though none of that has come into fruition yet, they are suggesting the very good possibility that the Atlantic is capable of this this year.

[Hammy]

If anyone can answer, roughly how long after the run does the public Euro come out?

[meriland23]

If anyone can answer, roughly how long after the run does the public Euro come out?

00z already came out. Euro generally comes out at about 2 am CDT for the 00Z and 1:30-2 pm for the 12z