Upcoming week - July 16-22

[Andrew92]

Evaluating last week

This past week my prediction was simple. I predicted no tropical or subtropical activity to occur. But I did also indicate if something were to happen, it would probably be off the East Coast from some kind of frontal system over the weekend. Well, a weak low pressure system did briefly form near Florida and is still present, but is disorganized and doesn’t appear to be developing further. There has also been an interesting feature east of Bermuda today, but I have heard it is non-tropical even though it looked well-organized earlier. It also isn't developing further. Therefore, my grade for this past week is an A.

Could something form this week? Let’s take a look.

Current situation and analysis

As mentioned, there is a weak area of low pressure off the coast of Florida. It is just north of the Bahamas and is very disorganized, with the heaviest thunderstorms a good distance south of the center of circulation. Only the NAM develops this feature tropically at all as it drifts north towards the Carolinas. Also, some tropical waves have pushed off the African coast in recent days, but no reliable models foresee any development coming from a tropical wave this upcoming week. Thunderstorms in these waves are weak to moderate at best right now too.

Also mentioned in my evaluation of last week, there has been a very interesting looking system flare up east of Bermuda. Even though there is no model support for development of this feature, thunderstorms have been impressive. However, this entity is also currently non-tropical, less organized than it was earlier today, and will likely continue off to the east and northeast without any further development.

There is one other area to look at though this upcoming week. It is way down the pipe, occurring not until Sunday. At about that time, the GFS and Euro are both picking up on a piece of low pressure becoming detached from a frontal system and potentially trying to develop. The GFS thinks it will develop just off the coast of North Carolina, while the Euro has it forming further east. Either way, any such system will likely head out to sea and only be of marine interest.

The MJO is right now strongest over the Indian Ocean, but that hasn’t stopped a recent strong of Hurricanes Daniel, Emilia, and Fabio from forming and intensifying quite impressively over the Eastern Pacific. Even in an El Nino year, who is to say it can’t happen in the Atlantic?

Recent history

In the satellite era, these storms have occurred during this upcoming week (and were not on the verge of dissipating):

Anna in 1961
Celia in 1966 (already active)
Becky in 1970
A subtropical storm in 1974
Claudette in 1979
Ana in 1985
Chantal in 1995 (already active)
Danny in 1997
Arthur in 2002 (already active)
Danny in 2003
Emily in 2005 (already active)
Franklin in 2005
An unnamed storm in 2006
Beryl in 2006
Bertha in 2008 (already active)
Cristobal in 2008
Dolly in 2008
Bonnie in 2010
Bret in 2011
Cindy in 2011

That’s a surprising number – 20 storms this upcoming week, equating to one about every two to three years or so on average. It drops to 15 though when looking at newly developed storms, though, but that’s still one every three to four years. But only four of these 15 new storms became hurricanes: Anna, both Danny’s, and Dolly. Storms coming close to that intensity by topping out at 65-70 mph include Becky, Ana, Franklin, Cristobal, Bret, and Cindy –six storms. That means there were a total of ten respectably strong storms from new tropical developments this upcoming week. The strongest was Anna back in 1961, a category 3 storm at its peak.

Also, seven of these 15 new storms came from tropical waves, while eight came from frontal systems. Of the aforementioned ten stronger storms, five came from tropical waves and five came from the frontal systems. Three of the hurricanes, including Anna, came from tropical waves. Only Danny in 1997 came from a frontal system, forming in the Gulf of Mexico. This storm was also the only storm to form from a frontal system in the Gulf of Mexico this upcoming week; the rest all formed off the East Coast or out at sea.

Also, with 2012 looking like an El Nino year, which storms formed in El Nino years of these 15? They would be 1997 Danny, the unnamed storm in 2006, and Beryl in 2006. However, Arthur did form on July 14, pretty close to the start of this week, and that was also in an El Nino year. All of these storms formed from frontal systems. As mentioned, Danny did become a hurricane but formed in the Gulf of Mexico. However, the other three storms formed just off the East Coast and peaked at no higher than 60 mph. Also of note is that in two other fairly recent El Nino years, there have been tropical depressions formed from frontal systems during this upcoming week or close to it. This happened on July 24-26, 1992, and July 20-21, 1994. My source for this next part is admittedly Wikipedia, but I also read in 1977, another El Nino year, that two short-lived tropical depressions also formed in the Gulf of Mexico. However, the origin of these two systems is unclear; one headed north and another east. This latter one seems suggestive of frontal origins.

So what does this all tell us?

You can probably read my mind a little up to this point. I have had this itching feeling that some kind of tropical system might form this upcoming week. But it will probably come from a frontal system off the East Coast. This is because 2012 is shaping into an El Nino year, and these types of systems are about the only chance of some type of tropical development this upcoming week. However, it has also happened frequently in recent El Nino years, with 1991 and 2009 being the only ones in which not even a tropical depression has formed near this time frame.

The best chance for any development will not be until about Sunday. That is when a frontal system will, if the GFS and Euro are correct, drop a low pressure system somewhere over the North Atlantic. History of recent El Nino years gives the best chance of this happening just off the East Coast, but no matter how close or far from the East Coast this system is, it should scoot out to sea. I will admit that the MJO is not in its most favorable phase right now in the Atlantic. But it also hasn’t been at its strongest over the Eastern Pacific, where three very impressive hurricanes have just come and gone. The MJO can’t be our guide alone.

The prediction

I’ll say it again, I really have a hunch we get tropical activity this upcoming week. It will take a while because it isn’t until about Sunday when we get the best chance of tropical development, but I think it will happen. I predict a tropical depression will form off the coast of North Carolina on Sunday morning. Before midnight that night, it will be a 45-50 mph tropical storm named Ernesto, heading east-northeast. Confidence is 70%.

Elsewhere, I predict no tropical or subtropical development from the low currently off the coast of Florida, east of Bermuda, from any tropical wave, or from any other system this upcoming week. Confidence is 90%.

-Andrew92

[Andrew92]

Oh and also, my next weekly update may either be running late or be from my phone. I will be in California all day on Sunday but returning home that night. I have no estimated time when that will be.

-Andrew92

[Andrew92]

Well let's evaluate.

This past week I had a feeling we might see some type of tropical development. The GFS and Euro models did indeed suggest such a possible development for Sunday from a frontal system. This middle part of July is also a somewhat conducive time historically for such developments to happen in El Nino years like this one. However, it didn't happen. The frontal system is there, but now nothing is poised to develop off the East Coast anytime soon. Therefore, my grade for this past week will take a hit for this.

However, I did accurately predict no other tropical developments for the week. While there were some interesting looking systems - first near Bermuda to start the week, then off Florida to end it - nothing materialized. I have had a habit of being bullish on systems like these perhaps developing, so at least some kind of a step in the right direction was made there.

But I still foresaw a development that although was early on suggested by models, has not happened or even looks imminent. Therefore, my grade for this past week is a C-.

Due to getting home very late from California, I am unable to do a full weekly prediction at this time. I will do a quick 24 hour prediction, and then my "official" one sometime tomorrow night. The tropical wave near Florida is fizzling out and not expected to develop. The frontal system the top models foresaw is there off the East Coast, but nothing is about to develop anytime soon. Therefore, I predict no tropical cyclone activity in the next 24 hours. Confidence is near 100 percent.

Lastly, I apologize for any major goofs as I am writing from my cell phone tonight. I will be back on the computer for the full weekly rundown tomorrow night.

-Andrew92