Upcoming week - July 19-25

[Andrew92]

Evaluating last week:

Last week was one in which frontal lows are more likely to develop into tropical cyclones than tropical waves. This phenomenon is also more likely to happen in an El Nino year than a year like 2010. Reliable models also did not foresee any development. Putting all these pieces together, my forecast was for no development.

Overall, not to brag, this forecast was executed very well. No tropical waves threatened to develop, and no frontal lows looked promising either. My grade for last week is an A.

You can see last week's at this thread:
viewtopic.php?f=31&t=108544

Onto this upcoming week....

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

Current situation and models

As we look at the current situation, there are no tropical cyclones in the Atlantic. There are, however, a few interesting areas that may be worth watching. The Central and Western Caribbean has a large disturbance that some models are hinting may develop, and the NHC gives a 10% chance of development here over the next 48 hours. There is also a tropical wave near the northern Leeward Islands that some models also want to develop, with the NHC also giving a 10% chance of development over the next 48 hours. However, the Euro model, which did a great job on Alex and TD #2, does not hint at development at this time. That said, the next run comes later tonight, and I will not see the run until I wake up tomorrow at the earliest.

Some members here are also talking about a new tropical wave coming off Africa - however, it looks like it is weakening at this time and I do not foresee this system developing, nor do any models

Looking down the road, at the weekend, the Euro model does hint at a strong tropical wave coming off the African coast. That is one thing, but will it develop? Time will tell.

Recent history

Since 1995, there have been five new tropical storms develop:

Cesar in 1996
Franklin in 2005
Gert in 2005
Cristobal in 2008
Dolly in 2008

That's a two-storm drop from last week, which may seem contradictory as we near August. But then, remember that of seven tropical storms for the period of last week, five came from frontal lows. Of this week's new five, only one came from a frontal low: Cristobal. So tropical wave developments actually increase slightly, from two last week to four this week.

Also, all of these five storms that developed were in "home-grown" areas. Franklin and Cristobal came just off the southeast coast, and Gert and Dolly near the Yucatan. Cesar appears to be an outlier, forming in the southeastern Caribbean - in fact, it was the first storm to develop in that area for this upcoming week since Hurricane Anna in 1961.

Only one of these storms, Dolly, became a hurricane this upcoming week (though Cesar became one shortly after this period, but that's for next week) - doing so in the Gulf of Mexico after forming into a tropical storm in the western Caribbean. Dolly then even went on to become a C2! Franklin and Cristobal were close, but couldn't quite pull it off as they headed out to sea, away from the East Coast. And while Gert developed in the Bay of Campeche, a combination of forming from a very disorganized disturbance and having little time to strengthen crippled its chances of getting stronger than 45 mph.

There were also six storms previously intact coming into this week:

Chantal in 1995
Danny in 1997
Danny in 2003
Emily in 2005
Beryl in 2006
Bertha in 2008

Chantal, 2003 Danny, Beryl, and Bertha were already at rather northerly latitudes. Beryl was just developing and would reach 60 mph, but no higher before clipping Nantucket and heading out to sea. The other three storms of these four would get no stronger and weaken before dissipating or becoming extratropical. It should be noted that Danny in 1997 also made landfall in Alabama on the 19th, weakened over land, and then re-strengthened into a tropical storm off the East Coast during this period. Like Beryl, maximum winds reached 60 mph as it neared Nantucket.

Only Emily remained in a tropical latitude the entire time, and re-strengthened from a minimal hurricane into a C3 over the Gulf of Mexico before making landfall in northern Mexico.

So what does this all tell us?

While tropical waves have a slightly better chance of developing than last week, the chances still aren't that good. If one does form, the best bet is in an area close to home. And if you're looking for a storm to form into a hurricane, the Gulf of Mexico remains as ripe as last week - Gert notwithstanding.

Back to looking ahead

So let's go back to this week. Tropical waves exist in the Caribbean and northern Leeward Islands that some models see development with. These are favorable areas, although the Leeward Islands wave probably will not develop until at least Thursday due to shear, and at this point be likely closer to the Bahamas. The reliable Euro, however, does not see development with either of these two. The wave currently coming off Africa would be expected to fizzle around this time, as would the strong wave the Euro sees coming off around probably Saturday.

The Euro is very reliable, and this week is still a very shaky week for development. However, seeing two waves in these areas near home makes my prediction for this week a bit tougher than last week. All this put together, however, and I think the wave in the Caribbean will be too slow to develop and run into land. I also think the Leeward Islands wave will struggle as shear increases. It may try to make a comeback by Thursday, but it could also have problems with land interaction around that time. The models that try to develop this system include the GFS, the NAM, and their supporting ensembles - not the most reliable ones in the world. I would also like to see what the NOGAPS and UKMET say before predicting this disturbance to develop.

Therefore, I predict no tropical cyclone development this week.

Confidence in this prediction is about 80%.

-Andrew92

[hurricaneCW]

I 100% agree with your forecast. Don't see anything developing this week, the EURO barely showing anything is a huge tip off. The slowly increasing chances for development during the upcoming week do probably mean that the quiet won't last for too long, I hope.

[LaBreeze]

Are we still being affected by the dry Saharan dust in the atomosphere and the High pressure building into the southeast?

[Andrew92]

Are we still being affected by the dry Saharan dust in the atomosphere and the High pressure building into the southeast?

The SAL is still going to keep development to a minimum this week. As for the high pressure, I do believe the Leeward Islands wave will keep moving west, and that is one reason why. The other reason is that with it struggling with shear, it will go with the lower-level flow, and if I'm right that would keep it moving west. That is also why I would not be surprised to see land interaction, as it may run into Hispaniola and/or Cuba.

-Andrew92

[OuterBanker]

I know, hindsight is 20/20. Looks like this forecast will bust. The PR/DR mess has become dominant and it looks like a sure thing now. Plus the new massive wave that has just emerged off the EC of Africa looks promising (not to mention the one behind it).

[NOLA2010]

Looks like Andrew92 Forecast = Fail

[Andrew92]

Well, it's looking bad. But I'm not giving up until this thing actually develops!

I also do remember the wave that became Dolly was at Code Red east of the Lesser Antilles, and we all know how that worked at the moment.

-Andrew92

[Macrocane]

It doesn't matter if your forecast fail, sometimes even the NHC fails, the important thing is to keep on doing this weekly analysis because they're very interesting, we will be very grateful.

[Andrew92]

That is a good point Macrocane, and it is true that sometimes you have to learn through mistakes and failure, so I can't beat myself up too much.

That said, my initial thoughts about shear and land interaction are being discussed in the main 97L thread. And the Euro still does not seem to be high on development. Still plenty of time, but my theory is, 48 hours in, at least holding true for now.

-Andrew92

[cycloneye]

Well Andrew, it may be a close call to have a TC this week as we know what is going on with 97L so your analysis may prove correct after all.

[Andrew92]

Well, here comes my evaluation, as nothing else is coming later today/tonight.

The previous week is a tough week for tropical cyclones to develop. The favored area is close to home, preferably in the western Caribbean or Gulf of Mexico. I went against the Caribbean disturbance development, which was correct. However, the Leeward Islands wave eventually became Invest 97L and then Tropical Storm Bonnie, whiffing my prediction of no tropical development. Granted, it only gather maximum sustained winds of 40 mph, but this part was blown. I was also correct, though, in predicting no development near the African coast.

But in hindsight I probably should have seen the movement further north, avoiding Cuba, which might have allowed me to predict further development, albeit not very strong given the reliable models’ prognostications. Therefore, my grade for this week is a D.

-Andrew92

[Macrocane]

I would give you a C+

I'm impatient to see the next update.

[Andrew92]

I actually thought about a C-, given I did very well elsewhere, but I shouldn't have let Bonnie sneak up on me like I did. Therefore, I did blow that one pretty bad, even though it still was pretty week - hence the D, but I knew I didn't deserve an F.

This coming week is now up, too!

-Andrew92

[Portastorm]

I actually thought about a C-, given I did very well elsewhere, but I shouldn't have let Bonnie sneak up on me like I did. Therefore, I did blow that one pretty bad, even though it still was pretty week - hence the D, but I knew I didn't deserve an F.

This coming week is now up, too!

-Andrew92

Andrew92, I respect the fact that you come back at the end of week and evaluate your forecast. Most folks don't do that. Take these C minus weeks as good learning experiences which will make you better, more knowledgeable! Anyhow, keep up the nice work. I appreciate what you contribute to S2K.