New depression likely forming in Bay of Campeche – otherwise quiet

The only area of interest is in the Bay of Campeche

The only area of interest is in the Bay of Campeche

It looks as though we will start the month off with a new tropical depression. Invest area 99L is trying to organize over the eastern Bay of Campeche, not far off the west coast of the Yucatan peninsula. Overall, conditions appear favorable for this system to develop and it should become a tropical depression later today or tonight over the very warm waters of the region.

The NHC has tasked a Hurricane Hunter crew to fly out and investigate the area and that will tell us a lot more about the structure, surface pressure and wind speeds. I suspect they will find it being close to depression status when they get there later this afternoon.

Track models suggest strongly that a west-northwest path will commence, taking the system in to Mexico in a couple of days. It looks like 100 miles either side of Tampico is a safe bet but since we are talking about a fairly weak system, so far, rain will be the primary concern here.

Speaking of intensity, none of the models indicate any rapid intensification but this does not preclude the chance for modest strengthening before landfall in Mexico. I fully expect that we will see a tropical storm out of this – if so, the name will be Dolly. However, as I alluded to in the previous paragraph, wind will not be as much of an issue as heavy rain will be. The terrain of eastern Mexico rises quickly not far inland from the coast. Flash flooding and mudslides could be an issue as the system moves inland and dies away later this week.

I do not see this system being much of a threat to Texas as strong high pressure parked over the southern part of the United States should keep what ever develops suppressed far to the south. Tropical storms and hurricanes are generally steered around high pressure areas, not in to them. There may be an increase in moisture from the onshore flow and persistent southeast wind but that is about the extent of it.

The rest of the Atlantic Basin is remarkably quiet this first day of September. In fact, I see very little in the global models over the next few days to be concerned with. So, I will stay focused on 99L and its likely eventual growth in to the season’s next tropical depression or storm.

I’ll post more here later this evening once we learn more from the Hurricane Hunters investigating the area.

M. Sudduth 12:54 PM ET Sept 1

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A storm for the ages? Perhaps. First, it is a Caribbean concern

99L about to become a tropical depression in the Caribbean Sea

99L about to become a tropical depression in the Caribbean Sea

There are very few instances when I have posted a headline like the one in this blog. Hype is not a tool I use to get the attention of my audience unless it is warranted and I feel it could help to save lives and property. What I am seeing in some of the global models is worthy of getting your attention and if it’s hype, then all the better in the long run.

There is a storm brewing in the Caribbean that will soon get a name: Sandy. Right now we know it as 99L, an area of investigation with potential to develop. Within the next 10 days, we may remember it as one of the great ocean storms of recent memory. Before all of that, it will be a problem for the Caribbean and that much is certain.

So far, development of 99L has been slow. It now looks as though things are coming together in the western Caribbean, a few hundred miles south of Jamaica. Water temps are as warm as could be and upper level winds are becoming more and more favorable. The NHC gives the area an 90% chance of becoming a tropical cyclone within 48 hours. I think it’s as good as done at this point and we’ll soon have TS Sandy to track.

72 hour ECMWF showing "Sandy" over Jamaica

72 hour ECMWF showing "Sandy" over Jamaica

People with interests in Jamaica need to be watching this system closely. It will bring periods of heavy rain and an increase in wind as it moves slowly towards the northeast with time. This slow forward motion is going to be a problem as the tropical rains will have a lot of time to fall over the same area for a couple of days or more. I would also not be surprised to see this become a hurricane before it reaches Jamaica. Intensity prediction is very poor even in this day of high-end computer models. Hopefully we’re only talking about a weak tropical storm in a few days but remember that hope is not a good planning tool. Being prepared is far better.

After Jamaica, the threat shifts to Cuba, Hispaniola and the Bahamas. Here too, the main issue will be excessive rain from what is surely to be “Sandy” by mid to late week. How strong it is depends on how quickly it can develop a solid inner core. Interests in the region should be paying close attention to what happens as this feature grows. We are not talking about an “in and out” system that gets kicked in to the Atlantic in a day or so. I think the big story will be the heavy rain even if this does become a hurricane in the Caribbean.

It’s what happens after the Caribbean that has the potential to make this storm one that people talk about for a long, long time.

Day five of the ECMWF showing "Sandy" after moving through the Bahamas

Day five of the ECMWF showing "Sandy" after moving through the Bahamas

To put it in simple terms, some of the global models are indicating that this storm will get caught in the southwest Atlantic and grow in to a hybrid mix of a hurricane and a Nor’easter the likes we have not seen since as far back as 1991 with the “Perfect Storm”. The closest event I can recall is “Nor-Ida” in 2009 which took the tropical leftovers of hurricane Ida from the Gulf of Mexico and transitioned it in to an epic ocean storm that blasted the North Carolina coast and points north. I was in that one and will never forget it. This storm could make that one look like a day in the park.

It all seems to have begun yesterday when some of the global models began to change their track for 99L from an out to sea event to one that may affect people from Florida to Maine. The Canadian was one of the first to show it. Then the American based GFS and finally, the very reliable ECMWF or Euro. People began talking about it within the weather blogs as if sniffing out something that movies are made out. It was incredible to read what people were saying could happen if this came to pass. Surely it was a one time fluke in the models and things would return to normal a mere 12 hours later. Not so much.

The overnight run of the Canadian global model shows pretty much the same scenario as yesterday. It takes what would be Sandy and turns it in to this enormous ocean storm that would cause coastal flooding, high winds and heavy rains for a large portion of the U.S. East Coast.

Day 8 of the ECMWF which shows a powerful coastal storm impacting the Mid-Atlantic region

Day 8 of the ECMWF which shows a powerful coastal storm impacting the Mid-Atlantic region

Looking at the latest Euro run, it too continues its forecast of developing a very large and powerful storm as the tropical energy from what would be Sandy gets pulled in to a deep trough digging in. This entrainment and phasing is rare but when it happens, it can lead to very powerful hybrid storms that have both tropical and non-tropical characteristics. The Perfect Storm in 1991 was just such an example. The overnight run of the Euro is jaw-dropping, there is no other way to describe it.

On the other hand, the GFS has all but abandoned this idea and simply sheds off the energy from the tropics in to a separate ocean storm way out in the open Atlantic. The result is….nothing. No big storm once 99L/Sandy leaves the Caribbean. It is remarkable to see such vast differences in the models and goes to show how complex the situation is. We are talking about an event that is forecast by some of the models to take place more than a week away. I debated whether or not I should even discuss it since it’s so far out in time. But I figured that rational people who read my blog would understand and appreciate the heads up if this in fact comes to pass….the bad storm that is. Maybe it’s all just a fantasy by the models that show it and the only concern, albeit a very legitimate one, will be for the Caribbean and the Bahamas. If not, and this storm happens the way the Euro shows it and the GFS showed it yesterday for a time, then we will be talking about this well past the hurricane season.

For now, we wait and go with the short term which is that we see what is a developing tropical depression in the western Caribbean. The first impacts will be felt in Jamaica and eastern Cuba. From there, we will just have to see how things turn out. The next several days could be very interesting if not very important in shaping how the hurricane season comes to an end.

I’ll post another short update this evening to go over the latest on the situation in the Caribbean. I’ll also have the video blog posted to our iPhone app by early this afternoon and it will incorporate the overnight model runs as well as the early morning or 12Z model runs to compare. If you don’t have our app, you’re missing out on a great tool in the daily video blog. It brings this discussion to life with numerous graphics, satellite shots and an in-depth explanation of what’s going on in the tropics now and what’s forecast several days out.

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Major changes with models for 99L that could lead to significant impacts for East Coast

GFS depiction of tropical cyclone over eastern Cuba in 96 hours

GFS depiction of tropical cyclone over eastern Cuba in 96 hours

There is a lot to discuss regarding the future track and intensity of 99L as it could affect literally millions of people from the Caribbean to the U.S. East Coast.

First, the current situation. Right now, 99L is rather disorganized over the Caribbean Sea but is forecast by all of the global computer models to gradually organize and become a tropical cyclone within the next two or three days. It looks like Jamaica, eastern Cuba and Hispaniola could be in line for quite a bit of rain and wind by the middle of next week.

By Thursday, the GFS places a strengthening tropical cyclone over eastern Cuba with heavy rains spreading across the southeast Bahamas. Water temps in this region are still very warm and it is possible that we could be looking at a rather strong tropical storm by this point as most of the guidance suggests steady strengthening.

By late next week, most of the reliable model output suggests a track in to the northern Bahamas, not too far off the Florida east coast. This is important because there is likely to be an indirect impact to Florida because of the presence of this system and a high pressure area to its north. It appears that a fairly strong surface high will move off the Northeast coast late next week and it could do two things. First, the high pressure north, coupled with the deepening low pressure off of Florida, will create quite a strong pressure gradient. This means the winds will be quite stiff out of the northeast for a good deal of the east side of Florida. So at the very least, rough surf and rip currents are a good bet towards the end of the week for Florida.

Sea surface temps along East Coast running at least 2 degrees above normal

Sea surface temps along East Coast running at least 2 degrees above normal

The other issue is that this high could act to block what would presumably be “Sandy” from turning out to sea. In fact, both the GFS and the ECMWF show this scenario and take what looks strong enough to be a hurricane right in to the East Coast of the U.S. somewhere north of Cape Hatteras. Sea surface temperatures in this region are running a couple of degrees above normal for this time of year and have not been disturbed by a previous hurricane earlier in the season. We are going to have to watch the evolution of this pattern very carefully over the next few days. What looked like a sure bet to send “Sandy” out to sea is no longer such a home run, so to speak. This could mean that people from the Caribbean Sea to Florida and eventually the East Coast have to deal with some degree of a tropical system over the next week or so. Interests in Jamaica, Cuba, Hispaniola and the Bahamas need to watch this system closely. We’ll see how things progress and can focus more on potential U.S. impacts as we get in to next week. For now, it looks like a slow process for 99L to develop but once it does, there is potential for it to impact a lot of people over a wide geographic swath.

I’ll post more here about 99L tomorrow morning. I also will be posting regular video blogs to our iPhone app which is a great way to visually understand what I discuss here in the blog posts. If you don’t have the app, there is no better time to get it. We’ve recently added our own tracking maps and of course have the exclusive in-field weather data, live web cams and video blogs should a landfall take place.

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Tropical depression and eventually a hurricane could form from 99L in the Caribbean

A look at invest 99L in the Caribbean Sea

A look at invest 99L in the Caribbean Sea

The MJO and climatology are working together to bring about what I have been alluding to for the past couple of weeks. It seemed almost inevitable that at least one more named storm would develop in the Caribbean Sea and the way things look now, it’s only a matter of time.

We have 99L moving through the central Caribbean this afternoon. The NHC gives it a high chance of becoming a tropical depression within the next couple of days. Water temps and ocean heat content in the region are high while upper level winds continue to become more favorable. Most of the reliable intensity models indicate that 99L will become a tropical storm and eventually a hurricane. Before any of that happens, it will be a persistent rain maker for the region. This will have its own set of problems as areas like Jamaica, Hispaniola, eastern Cuba and eventually the southeast Bahamas could see a lot of rain over the next several days.

The problem is that steering currents are relatively week. This is not a system that will develop and scoot out rapidly to the northeast. It’s going to take some time, perhaps nearly a week, for it to clear the Caribbean entirely. This will lead to excessive rain fall totals for some of the islands in the area and this needs to be taken very seriously. Tropical cyclones and even those in the genesis stage can dump 10 to 20 inches of rain in short order. The longevity of this event for the Caribbean is going to be serious.

For now, the track of the low pressure area will be west and south of west for a couple of days. This will place the low in the western Caribbean first as it awaits a pattern change that should spring it loose and eject it out to the northeast. Exactly when this happens remains to be seen but none of the guidance shows it impacting Florida. However, the impacts to Jamaica, Cuba and Hispaniola could be significant, especially with the aforementioned rain event.

In the longer term, the models suggest that what is almost certain to become “Sandy” will strengthen in to a hurricane. When it does so is tough to say, it could be after it tracks out of the Caribbean which would be good news. My only concern is all of the warm water available and the inability of the models to do well with intensity forecasting historically. Interests in the entire area need to monitor 99L’s future progress very closely.

I’ll have another post here tomorrow. If you have our iPhone app, be sure to check the video section for today’s video blog as it has been posted recently.

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99L getting a little better organized as we round out July

A look at invest area 99L indicates that it is getting somewhat better organized today. A general increase in shower and thunderstorm activity can be seen in satellite imagery although it is still rather poorly organized.

For the most part, the global models are not very bullish on 99L developing much in the coming days. The GFS suggests some strengthening and it is possible that this system becomes a tropical storm as it moves towards progressively warmer water. There is still some dry air around, enough so to limit the deep convection needed to allow 99L to thrive and grow at a rapid pace.

The NHC’s intensity model, SHIPS, shows modest intensification but keeps 99L below hurricane intensity. Yesterday, that same model suggested that it would in fact become a hurricane.

The ECMWF model or Euro, shows very little in the way of strengthening as the system moves towards the Lesser Antilles.

The bottom line here is that it appears some slow development is possible as 99L tracks generally westward towards the Windward Islands. Interests there should be ready for at least an increase in shower and thunderstorm activity in the coming days. I would not be surprised to see 99L become a tropical storm but it would probably be fairly weak and not very organized. Once it moves in to the Caribbean Sea, conditions are generally not very favorable for continued development.

Elsewhere, another tropical wave is moving through the Greater Antilles islands today and will spread showers and thunderstorms across Puerto Rico, Hispaniola and eventually Cuba. None of the reliable computer models indicate that this wave will develop in the coming days. Keep in mind that tropical waves often bring periods of gusty winds and squally weather. Conditions will improve across the region by tomorrow as the wave passes on by.

Speaking of tomorrow, our app, HurricaneTrack, hits the App Store. I will have a full blog post about it and the special limited time price that we will be offering as we officially roll out version 1.0. The app will feature a daily video blog plus live weather data during hurricane and tropical storm landfalls. This version will be just the start as we plan to add more features- but that will depend on YOU to help make it a success. We will have an Android version available just as soon as possible so no worries for our Android device users, we’ve got you covered too!

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