Upcoming week - June 27-July 4 (extended)

[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

Last week I predicted no tropical cyclone development, but confidence was a slightly lower 80%. That was because of the possibility of a disturbance in the Bay of Campeche that may try to get going, well, today, on Sunday, June 26. Still, I predicted no development (yet) due to models saying it wouldn’t be all the way there by the end of Sunday night. Indeed, this disturbance hasn’t quite even reached the Bay of Campeche just yet. While it is organizing, it hasn’t developed into anything yet either. Therefore, due to correctly calling for no tropical cyclone development, while still having an idea of what might come, this week’s prediction is another solid A until factoring in something else…

Yes, I did go for a little extra credit with Beatriz, honing on how strong it would be as it brushed Manzanillo. It did brush that city, but as a C1 storm with winds of about 85 mph, not a C2 with 100-105 mph winds like I thought. Overall, it was stronger than some predicted, but not quite in line with my extra-credit prediction. Therefore, the grade stays as an A for this past week.

Now it gets tough. I’m just hoping for no repeat of a blown Invest 94L prediction this week. Here we go! Due to a holiday weekend, I am extending this one day to Monday, July 4.

Current situation and models

By now you’ve probably figured out that a disturbance in the western Caribbean bears watching for potential tropical cyclone development. Remember though, models last week said it would occur in the Bay of Campeche or southern Gulf of Mexico. The models are still saying that is the more likely scenario. By looking at when reconnaissance flights may be scheduled to fly out, right now the earliest I’m seeing is on Tuesday. Models did say this was a prime date for development last week, and this date still appears to be as good as any for this system to develop if it does. Waters are very warm in this part of the Atlantic, shear is diminishing, there is no dry air really to speak of, and the MJO may be getting a little more favorable for something to occur in the Gulf of Mexico or Bay of Campeche.

Should this disturbance develop, a ridge of high pressure to the north will probably scoot this thing westward into Mexico. It may try to move a little west-northwest to northwest as the ridge weakens a little, but not a lot. Models are saying a potential landfall in Mexico could occur sometime on Wednesday, with some south of Tampico, some north, but the majority near that city. This tells us the steering currents are pretty well-established in that direction. The mountains over Mexico will then likely dissipate this entity rather quickly after coming ashore.

Elsewhere, there are some whispers of a tropical wave that may try to get going in the MDR, or Main Development Region, between Africa and the Lesser Antilles. However, our good friend SAL is looking to keep a lid on things over here, pushing the ITCZ very far south where there’s less Coriolis effect to help a disturbance spin. Nowhere else looks suspect for any development this upcoming week.

Recent history

During this upcoming week, June 27-July 4, the following storms have developed since 1960:

Becky in 1966
Alice in 1973
Amy in 1975
Bret in 1981
Ana in 1991
Alberto in 1994
Ana in 1997
Bill in 2003
Bret in 2005
Bertha in 2008

Out of these ten named storms, only Becky, Alice, and Bertha would go on to become hurricanes. Where did they form? Becky and Alice formed near Bermuda and went north, while Bertha developed right off the coast of Africa, and became a hurricane much later. Bertha was also the only storm during this upcoming week to form in that part of the world.

Of the rest of the storms, three of them developed close to the Bay of Campeche: Alberto, Bill, and 2005 Bret. In particular is Bret, which actually formed in the Bay of Campeche and then moved west quickly into Mexico as a just-developing tropical storm. Alberto and Bill headed north to the Gulf Coast and got quite a bit stronger, with winds in each reaching about 60-65 mph.

The rest of the storms, Amy, 1981 Bret, and the two Ana’s, all developed in subtropical latitudes off the east coast. Bret actually headed west into Virginia, but the other three all headed out to sea.

Only Alex from last year was still active and over water coming into this upcoming week. A couple other storms like the unnamed 1960 storm and Bonnie in 1986 were technically still active, but were already weakening over land. Alex was over the Yucatan Peninsula and preparing to emerge in the Bay of Campeche coming into this week as a minimal tropical storm. 48 hours after emerging, it became a hurricane. 24 hours after becoming a hurricane, it struck northern Mexico with winds reaching 105 mph, a rare C2 hurricane in June. That’s a total of 72 hours over the warm Gulf of Mexico!

Now, though Bonnie was dissipating over land by this time, it did become a hurricane prior to striking. What separated that storm and Alex, from storms like Alberto, Bill, and 2005 Bret? Those two simply had more time to organize over water. As noted above, Alex spent 72 hours in the Gulf of Mexico. Also, this storm had a bit of a head-start, coming into the Bay of Campeche as a minimal tropical storm, not just a disturbance or tropical depression like some others. Though Bonnie wasn’t quite that advantaged, it still found just enough time in 60 hours over the Gulf of Mexico to become a minimal hurricane. Alberto had about 48 hours or so to strengthen, and Bill had 36-48 hours or so. That was just not enough time for either of these to quite become a hurricane, though they both were moderate to strong tropical storms at landfall (60-65 mph each). And Bret, well, if the system develops about right where it ultimately makes landfall, intensification chances are just slim to none. It was well-organized though, and with more time I do suspect Bret may have been a slightly stronger storm.

So what does this all tell us?

Boy that’s a lot of information to digest! Still, what we can learn is that the Bay of Campeche is indeed somewhat of a hot spot for activity. With conditions getting favorable for development there in a couple days, development appears likely as a disturbance rolls in. My well-known albatross of predicting the timing of development is going to come into play though. Then, I have to nail the path and how long over water this system may have. If this disturbance were to last closer to 60 hours or longer, a hurricane could develop. If it’s shorter, probably just a moderate to strong tropical storm at most intense. However, with models indicating a landfall possibly on Wednesday, it may not even become that.

The disturbance that may come in the Main Development Region may come to pass looking at Bertha, but it’s pretty unlikely at this point. Actually, if you’re feeling development outside the Bay of Campeche, look off the East Coast for a storm forming from some kind of frontal system. Then again, that would probably be typical in an El Nino situation, which 2011 is not.

The Prediction

It’s a tough prediction involving a disturbance that isn’t even an Invest yet, and hasn’t reached the proposed area of development. Still, this is the best chance of development yet this season, models are all over something coming out of this, and conditions are much more favorable than they were for Invest 94L. I am more confident that the lessons I learned from that gaffe will help make this a better call for what will happen in the Gulf of Mexico. OK, enough waffling. I predict a tropical depression will develop in the Bay of Campeche on Tuesday while heading west-northwest toward Mexico. As it heads in that direction, maybe even making an ever-so-slight jog northwest, it will become Tropical Storm Arlene before the night is over. On Wednesday, Arlene will make landfall near Tampico, Mexico. It will have spent about 24-36 hours over water, and in that time will have grown to a modest tropical storm with winds reaching 45-50 mph. Arlene will rapidly weaken and dissipate overnight, but produce a flooding threat in the states of Tamaulipas and Nuevo Leon in the process (cities threatened will include primarily Ciudad Victoria and Montemorelos, but Monterrey could receive some flooding too). Rains will also reach into south Texas, though not as significant as in Mexico. Confidence is 60%.

Elsewhere, I predict no tropical cyclone activity in the Main Development Region or anywhere in the Atlantic before the end of the long holiday weekend. Confidence is 90%.

-Andrew92

[Macrocane]

I agree that this is a tough one, the models have been back and forth with this system and the wave still has a lot of work to do, I think it could become a TD or a minimal TS. Let's see what happens, good discussion as always.

[Ptarmigan]

Interesting you mentioned Unnamed 1960 Tropical Storm and 1986 Bonnie. Both made landfall on Texas. 1960 tropical storm is responsible for wettest June and summer for Upper Texas Coast. It was also responsible for heavy rain and floods. This happened after a really dry spring in 1960.

Divisional Data
http://www7.ncdc.noaa.gov/CDO/CDODivisionalSelect.jsp

[Andrew92]

Well, the long week is pretty much done and there won't be anything on any 11 PM advisory, so let's evalute.

Let me first say, that I have made a HUGE step towards getting rid of that monkey on my back that is getting the timing right for the development of a tropical cyclone. I predicted development of a tropical depression and storm both to happen on June 28…and it happened right then. For anyone who recalls, I even had June 28 pegged in the previous prediction! Now I have to think, did I just get lucky or am I actually getting better at that?

That’s because beyond that, I had some issues. I predicted Arlene would have 24-36 hours over water and would reach maximum winds of about 45-50 mph. Well, it spent a little longer than that over water, and got to 65 mph. The intensity would have been wrong anyway even inside the window as it did reach 60 mph, but the timing of landfall hurt it a little more. That said, the landfall location was correct near Tampico, and the rainfall threat and location going up towards Monterrey was also well-executed. But I also underestimated the threat, as its rains did make it further west a bit. Lastly, dissipation occurred a little slower than I anticipated, probably due to being a stronger storm at landfall than predicted.

I was correct in predicting no other tropical cyclone activity. And what was that about something off Africa again?

Overall, my discrepancies with Arlene were unfortunately there, though a bit less so than it may have been last year. This storm showed I am making progress, but I still have a bit more to go. Then again, this was a mildly tough prediction to get right, with many models also underestimating this storm. Overall I give myself a B- for this past week.

A shorter version for this upcoming week coming in a few, we're resuming to the normal, until Sunday night schedule now.

-Andrew92

[Hurricaneman]

you did good this week lets keep up the momentum into next week