Upcoming week - July 9-15

[Andrew92]

Evaluating last week

The only remote possibility I could find for any kind of tropical or subtropical activity for this past week was from some type of frontal system off the East Coast. There was a low pressure system emerging over the ocean off the Carolinas which might have look enticing. However, no models foresaw it developing tropically, and the thunderstorms that did develop were primarily from daytime heating. When putting these together, it was just too hard to imagine such a system developing into something with a warmer core. With nothing else looking to develop, I simply called for no activity for the week. That is just what happened, so my grade for this past week is an A.

My weekly column is on a roll so far this year with only one bad week! How about another good week?

Current situation and models

The Atlantic basin is very quiet to start this new week. Nothing imminent seems to be developing over the next few days, and no reliable models show any tropical disturbances potentially developing this upcoming week. Of course, 2012 is proving to be an El Nino year, and per some recent analyses I have put together it may be wiser to look for frontal systems, particularly coming off the East Coast. The Euro and GFS models do show some impressive-looking fronts off the East Coast this upcoming week, but there do not appear to be any independent systems at the tail ends of them, at least for now. However, the GFS does show a pretty interesting looking system off the Mid-Atlantic States sometime around next Tuesday, with maybe another such system later in the week. Or is it the same system, lingering for a while? It's a little hard for me to tell. Oh wait, that’s getting ahead of myself, but still, it’s interesting to bring up anyway.

Recent history

Since 1960, these storms have developed during this upcoming week:

Abby in 1960
Celia in 1966
Bob in 1979
Barry in 1989
Chantal in 1995
Bertha in 1996 (already active)
Bill in 1997
Claudette in 1997
Arthur in 2002
Claudette in 2003 (already active)
Dennis in 2005 (already active)
Emily in 2005
Bertha in 2008 (already active)

That’s another 13 storms for this upcoming week, pretty impressive looking. However, only four of them were in El Nino years: Celia (and this El Nino was fading at the time), Bill, 1997 Claudette, and Arthur. Celia and Bill did manage to become hurricanes briefly, but the other two were much weaker. Celia also did form from a tropical wave, but struggled to intensify until she headed northeast out to sea; that is when and where she became a minimal hurricane. For the sake of completeness, of the other nine storms, seven became hurricanes with a surprising four becoming at least category 3 storms! Only Barry in 1989 and Chantal in 1995 of this bunch did not become hurricanes, but they did both top out at 70 mph, coming awfully close.

I would also like to note that five storms in the last 15 years have also formed within a couple days or so after July 15. Those storms are Danny in 1997, Danny in 2003, an unnamed storm in 2006, Beryl in 2006, and Bret in 2011. Two of these storms became hurricanes: the two Danny’s, although Bret also came mighty close last year at 70 mph. Also, three of these storms occurred in El Nino years: 1997 and 2006 were such years. The two storms in 2006, like the other aforementioned storms, formed off the East Coast from frontal systems. 1997 Danny did also form from a frontal system, but in the Gulf of Mexico.

So what does this all tell us?

Indeed, it will be very hard for any tropical wave to get going during this upcoming week. Since 1960, only once during an El Nino year has such a system become a tropical storm during this upcoming week – and that El Nino was weakening to begin with. Still, that storm, Celia, did struggle for a while before it started turning north, where it began to intensify more markedly, perhaps proving that El Nino still had some influence at that time.

What else is interesting is that in recent years the days around July 15 form kind of a mini-spike in tropical activity in El Nino years. Yes, it didn’t happen in 2009 (the only other recent El Nino year since 1997), but all the other “real” El Nino years (i.e., not Modoki year 2004) had something close to that date form off the East Coast from a frontal system. Danny in 1997 also showed it can, albeit rarely, happen in the Gulf of Mexico as well. With the GFS showing an interesting system for next week sometime off the Mid-Atlantic states, it would be foolish to completely write off any such developments from such a system around the weekend or so. The track would likely be one out to sea though, and likely not much stronger than a moderate tropical storm. Of course, it's hard to say right now if any such system develops, and if it does, if it is tropical or subtropical at all.

The prediction

I also have to admit, I just have that feeling that something may be coming off the East Coast somewhat soon. That doesn’t mean it will happen this week, but we are approaching a pretty good time to be looking in that area for some kind of tropical or subtropical development. But it’s probably best to look at the models, which do not show anything quite yet during this upcoming week – though the GFS may be hinting at something shortly after that. I predict no tropical or subtropical activity in the Atlantic this upcoming week. Confidence up to Friday is 90%, from then on is 70%.

-Andrew92

[Andrew92]

Well, it is time to evaluate.

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.

New week coming up shortly.

-Andrew92