Upcoming week - July 18-24

[Andrew92]

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.

Evaluating last week

Well, I correctly called for no development in the western Caribbean. Elsewhere, I didn’t see anything else that looked threatening for development, even according to reliable models. An Invest that went into Mexico early in the week came awfully close, but officially is not listed as having developed. Any more time over water, and this would not have been a good grade. However, Tropical Storm Bret has also just formed tonight off the coast of Florida. This one really snuck up on a lot of models for the time, and also me. Still, the damage is limited to a minimal tropical storm in the last hours of the week, and otherwise there were no other developments. Despite the Sunday damage, this week’s grade is still a B+.

This week looks really funky coming up, with now a new tropical storm to deal with and maybe another later this week. What will happen?

Current situation and models

Tropical Storm Bret is poised to head northeast, away from the United States. It is not a very well-organized storm, and no model strengthens it into a hurricane. Another thing pointing to little further development is just how much this snuck up on some people. Historically (getting ahead, I know), these ones that get little respect from models until they develop don’t seem to do anything significant (examples being Chris in 2006 and Gaston last year).

But several models, including the Euro, are hinting at a possible Gulf of Mexico development on about Tuesday or Wednesday. There is a weak area of low pressure over Alabama. Whether or not it makes it off shore will have big implications towards development or not. Regardless, a rain threat should be expected in this part of the world at some point this upcoming week.

Recent history

During this upcoming week since 1960, the following new storms have developed:

Anna in 1961
Dorothy in 1966
Ella in 1966
Becky in 1970
Bob in 1985
Arthur in 1990
Franklin in 2005
Gert in 2005
Beryl in 2006
Cristobal in 2008
Dolly in 2008
Bonnie in 2010

Of these twelve storms, only four became hurricanes: Anna, Dorothy, Bob, and Dolly. Anna and Dolly both formed in the Caribbean, Bob formed in the Gulf of Mexico, and Dorothy developed far out at sea. That said, Dolly became a hurricane in the Gulf of Mexico, while Bob became one off the Southeast Coast.

Of the other storms, Franklin formed very near where Bret formed and followed a similar track to Bret’s forecast path. However, it became a very strong tropical storm at one point, with winds reaching 70 mph. Beryl and Cristobal didn’t form too far away either off of North Carolina, and each gathered 60-65 mph maximum winds on likewise similar paths. It would also be foolish to disregard the several storms that came from frontal lows the prior week, and a few were still active: a 1974 subtropical storm, Ana in 1985, and Danny in 1997. Yes, Danny was a hurricane, but in the Gulf of Mexico. It later re-developed off the East Coast and at that point would gather maximum winds of 60 mph at its highest. The subtropical storm in 1974 stayed weak, but Ana made a run at hurricane strength before becoming extratropical, with winds at one point reaching 70 mph.

As for what’s left, Dorothy developed in the Main Development Region and couldn’t really get going. Bonnie developed a bit further west but north of the Caribbean, and struggled even more before striking South Florida with 45-mph winds. Becky made a go for hurricane strength in the Gulf of Mexico but came up short. Arthur also became a strong tropical storm in the Caribbean, but failed to become a hurricane before dissipating. Gert formed in the Bay of Campeche but couldn’t get off the ground before striking Mexico.

Other storms still active from the prior week include Celia in 1966, Claudette in 1979, Chantal in 1995, Danny in 2003, Emily in 2005, and Bertha in 2008 (still). Celia, Danny, and Bertha were minimal hurricanes far out at sea, and Emily was a quite powerful one in the western Gulf of Mexico at this time. Chantal was the only one to fail to become a hurricane on its way out to sea, and yet still came close with winds reaching 70 mph.

So what does this all tell us?

Bret is forecast to reach a maximum intensity of 60 mph for now. But several storms on their way out to sea suggest it may try to get a little stronger before heading out. The ones that form closer to land and form from frontal systems generally have stayed weaker, so Bret’s chances of becoming a hurricane are still not all that good.

As for the possible Gulf development, Bob is probably the closest match to this one. Bob did become a minimal hurricane, but was further south and then had more time over water than this supposed system will probably have. Becky came close too in a similar area, but couldn’t quite become a hurricane. Also, Bob didn’t become a hurricane in the Gulf, but off the East Coast. I think this tells us we may get a marginal tropical storm, but probably no hurricane out of whatever may come. But the low looks quite weak right now over land, and it may need more time than it will get to really have a chance at much.

The Prediction

This one is not going to be easy. I’m very torn on that low approaching the Gulf of Mexico. On the one hand, several models are developing it, including even the Euro. But it looks really sick right now, and will probably need time to get going. Then again, the Gulf of Mexico is a known hot bed for activity, and there may be a nasty surprise in store for somebody.

I’ll actually do the Bret prediction first. This one shouldn’t be too hard as the path looks pretty straightforward. The intensity is always tricky, but Bret will probably not ever become a hurricane on its way out to sea. I predict Tropical Storm Bret will strengthen slowly at first on Monday, but on Tuesday morning reach a peak intensity of 60-70 mph. It will also be moving slowly northeast at this time, but move faster starting Tuesday night, when a weakening trend will commence as conditions get less favorable. Weakening will be slow, but Bret will be a 40-50 mph storm by Thursday when it will become extratropical. Bret will never hit land or cause any significant effects other than some rough surf along the East Coast. Confidence is 80%.

Now, as for what may happen in the Gulf, here is my call, and not the most confident one at that. I predict no development for this low pressure system, but there will be a threat of heavy rainfall along the coast as it hovers in the area. Confidence is 60%.

Elsewhere, I predict no tropical cyclone development this upcoming week. Confidence is 90%.

-Andrew92

[Andrew92]

Well, time to evaluate.

Oh boy. Well, let’s start with Bret. For the most part, I got this one right. I pegged the peak intensity of 60-70 mph perfectly as winds reached 65 mph. However, that occurred Monday night instead of Tuesday as I had predicted, but at least the timing was really only 12 hours or less. I also had Bret dissipating or becoming extratropical on Thursday, and it happened Friday morning. OK, still not the worst mistake I could make or have made. Besides, the timing of track and the general weakening were otherwise very solid, with a slow motion until Tuesday and then speeding up. All things considered, the Bret prediction was definitely not perfect, but still a very decent one.

I also was right in not buying into the low developing in the Gulf of Mexico into anything significant, which some models were drooling over. I should have been more confident, but accuracy still probably counts more than confidence when looking at the big picture.

The problem is that nobody saw Cindy coming whatsoever, including me. Granted, she was a fish that never came remotely close to land, but Cindy did get very respectably strong for an entity no model foresaw even as the system became an Invest, with winds as high as 60 mph. Confidence for no other development was 90%, and this really drilled that area to smithereens.

Add it all up: Bret’s grade is probably an A-, the Gulf an A, and everywhere else an F (thanks again Cindy for coming out of nowhere and then intensifying). Alright, I guess really only Cindy killed an otherwise very decent week for me. This week’s grade will be a B.

Last week in July's prediction coming right up.

-Andrew92