Upcoming week - November 14-20

[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

This past week was about pinning down what an extratropical low would do in terms of becoming tropical. These things are often notoriously difficult to predict on this front, just witness how bad I was early in the season. However, this time I did a pretty decent job on predicting Sean. It did become a subtropical storm slightly later than I thought, but intensified on cue to 50-60 mph on Tuesday as I thought. But I predicted a storm that wouldn't even last as long as it did. I thought Sean would be extratropical on Wednesday, but it strengthened tropically to a 65-mph storm instead, and didn't become extratropical until Friday. Still, I was right on the north and northeastward track. I should have addressed the threat to Bermuda, but it turned out to be minor.

Elsewhere, nothing developed as predicted. Overall, not a bad job at all on Sean all things considered. I give myself a B for this past week.

So how does this week look with Sean gone? Let's see here....

Current situation and models

Looking at the surface, there appears to be an interesting disturbance in the southwestern Caribbean. However, the National Hurricane Center is not interested in this system at this time and no reliable model develops it either, at least in the Atlantic (I say that because some models DO develop something in the EPAC this upcoming week, but that's another story.) One item I read over the weekend on Jeff Masters' blog was that several models, such as the GFS and Euro, are trying to develop a strong extratropical storm in the middle of the Atlantic and possibly make it tropical. However, I looked at the latest Euro run and wasn't impressed. I am thinking if anything does in fact come from something like this, it would be very weak. It is also unlikely to strike any land, including Bermuda.

Elsewhere, this week looks quiet with no areas of development anticipated.

Recent history

During this upcoming week, the following storms have developed:

Laura in 1971
Frances in 1986
Keith in 1988
Marco in 1996
Lenny in 1999
Gamma in 2005
Delta in 2005

That's a total of only seven storms this upcoming week. Of this set, Frances, Marco, and Lenny became hurricanes, with Lenny being the only intense one. It should be noted, however, that Laura, Keith, and Delta were all strong tropical storms that were only a few mph away from becoming hurricanes. Only Gamma didn't come close to that intensity.

Laura, Keith, Marco, Lenny and Gamma all formed in the western Caribbean. Laura, Marco, and Gamma remained trapped in the Caribbean. Keith re-curved into Florida and out to sea. And Lenny.... well you know the story about the "wrong way storm." Frances and Delta developed over the open Atlantic and never threatened land.

So what does this all tell us?

Frankly, the better chance would probably be for the Caribbean disturbance to develop this upcoming week. But nobody develops this system. Instead, models want to develop a system late this week from an extratropical system that looks unimpressive at best. But only two storms have developed out there in the satellite era. That said, one became a hurricane and the other was very close. Anything that does develop this upcoming week could be like Sean and get a little stronger than some expect at first glance.

The Prediction

It isn't easy to make a prediction on a storm developing this far out. Models insist on the possibility of development, but the Euro run just doesn't look impressive enough for my liking. The historical odds are also grossly against such a storm developing out there this upcoming week. It could happen....but I think not. I predict no tropical cyclone activity this upcoming week. Confidence is 80%.

-Andrew92

[Andrew92]

Well it is time to evaluate.

Overall, I was right on the money this past week. I wasn't as confident as normal for November on calling for no development, but indeed, nothing developed. The reason for the slightly lower confidence was a feature that some models were indicating to possibly develop tropically at the weeks end in the middle Atlantic. That feature did become Invest 99L, but becoming an Invest does not constitute development. Therefore, for seeing this possible feature, but calling for no development, this past week's grade is a solid A.

LAST prediction of 2011 coming up soon.

-Andrew92