Tropics getting very busy as we close out August

There is a lot going on, no doubt about that. It’s the end of August and the hurricane season is kicking in to high gear. Let’s start in the Pacific actually then move east from there…

TS Madeline/Hurricane Lester

TS Madeline is forecast to strengthen in to a hurricane as it tracks generally towards Hawaii in the coming days. It should weaken upon approach and perhaps turn more south with time.

TS Madeline is forecast to strengthen in to a hurricane as it tracks generally towards Hawaii in the coming days. It should weaken upon approach and perhaps turn more south with time.

We have a pair of tropical cyclones to watch closely in the east and central Pacific over the coming days. First up is tropical storm Madeline which is currently situated well to the east-southeast of Hawaii. The forecast calls for the storm to reach hurricane intensity as heads generally westward early next week. While the track suggests a threat to Hawaii, it seems as though less favorable conditions will set in and Madeline will weaken and probably push more south with time, avoiding a direct impact to the islands. However, as we know, this can change so it’s obviously a good idea to keep tabs on the progress of this storm.

Much farther to the east over the eastern Pacific we have hurricane Lester with 100 mph winds. It too is tracking almost due west and could reach the vicinity of Hawaii in about a week. It is something to monitor but remember, it is very difficult for hurricanes to make landfall in Hawaii from the east. We usually see hurricane threats from the south as they turn from lower latitudes and track northward across the region, such as Iniki did back in 1992. While Lester is a strong hurricane, I would not worry too much about it right now – plenty of time to watch.

99L

Morning track plots showing the spread of the various computer models. Most of the more reliable models suggest a landfall, if it were to develop, somewhere along NE Gulf of Mexico coast.

Morning track plots showing the spread of the various computer models. Most of the more reliable models suggest a landfall, if it were to develop, somewhere along NE Gulf of Mexico coast.

Next we have good ole 99L. Seems like it has been with us forever. The area of interest that just can’t seem to develop. So far, it still hasn’t and doesn’t look like it will anytime soon. Upper level winds continue to plague the would-be storm, pushing any deep thunderstorms that try to develop away from the low level center which is currently moving through the Florida straits and Keys area.

It has been a frustrating week tracking 99L with all of the computer model flip-flopping that we’ve had to deal with. About the only one that has been consistent with intensity is the hurricane specific HWRF model which goes bonkers with development on almost every run. So far, none of that has come to pass. The GFS has done fairly well indicating little development thus far and not much more to speak of in the days ahead. The Euro or ECMWF on the other hand has gone back to suggesting a hurricane threat for Florida and possibly the Southeast coast once the system moves back out over the Atlantic.

My feeling is that so far the system has under-performed and until the shear relaxes and we see deep convection wrapping around the low level center and maintaining for 24 hours or more, it won’t pose much of a threat as far as being a strong hurricane. That being said, it is possible that 99L could reach hurricane intensity somewhere in the Gulf of Mexico next week. Water temps are very warm and all it takes is a period of favorable upper level winds for the lid to come off.

I believe the next 24-48 hours is the key here. If we see it develop by Tuesday then folks in Florida could be in for some significant impacts from this system. Unfortunately we will just have to wait and see how things pan out. For now, it remains only a strong tropical wave of low pressure, nothing more.

91L

Invest area 91L with some deep thunderstorm activity near the center. It is moving towards the NC coast but should turn north and back out to sea before reaching Cape Hatteras and vicinity.

Invest area 91L with some deep thunderstorm activity near the center. It is moving towards the NC coast but should turn north and back out to sea before reaching Cape Hatteras and vicinity. (click to view animation)

Next we have invest area 91L between Bermuda and Cape Hatteras and moving westward with a turn more to the west-northwest expected soon.

Right now, strong upper level winds coming from the east are keeping the convection that has managed to develop just west of the well defined low level center. You can clearly see this on the satellite image I have posted here. In fact, this looks to me like it would be classified as a tropical depression but without recon in there to verify right now, it’s not officially anything but an area of interest. We should know later today once the recon crew gets in there – perhaps this becomes TS Hermine? We shall see.

The models are in pretty good agreement that this will turn more to the north and then curve back out over the Atlantic over the next couple of days. The key to any appreciable impacts to the North Carolina coast will be how close the system tracks before doing so. Most of the guidance keeps it just east of Cape Hatteras and vicinity but close enough to warrant concern, especially for off-shore boating interests.

I’ll keep a close eye on this one since recon is planning to investigate later today. Once we get their reports we will know if this has in fact become a next named storm or at least a tropical depression.

Hurricane Gaston

Hurricane Gaston track forecast showing it staying out over the open Atlantic.

Hurricane Gaston track forecast showing it staying out over the open Atlantic.

Gaston has become the strongest hurricane in the Atlantic Basin for 2016. Top winds are near 90 mph and are forecast to go up from there. The hurricane has developed an eye and is moving away from all of the hostile conditions that were hindering significant development over the past day or so.

The NHC is forecasting Gaston to reach peak intensity of 110 mph before reaching cooler water later this week. I won’t be at all surprised to see the hurricane reach 120 mph or more over the warm water of the sub-tropics. This seems to be the norm in recent years – hurricanes reaching peak intensity well outside of the deep tropics. Fortunately for land areas, Gaston will only be tracking over open ocean.

Future 92L in the far eastern Atlantic

Large tropical wave over Africa that will almost certainly be a named storm in the far eastern Atlantic in the coming days.

Large tropical wave over Africa that will almost certainly be a named storm in the far eastern Atlantic in the coming days.

A well developed tropical wave over interior Africa is forecast by all of the global computer models to move in to the eastern Atlantic and develop over the next five days. Conditions appear to be favorable across the entire swath of ocean this time around and we just might have something to track for days on end.

There is no doubt going to be a lot of talk about this system because the steering pattern looks to be one that could allow it track all the way to the United States. While this is a possibility, it is so far out in time that worrying about a specific location is pointless. Conditions appear to be favorable so let’s just watch and see what happens over the course of the week ahead and go from there. We have plenty of other issues to deal with on the west side of the Atlantic to keep us busy for a while longer.

I’ll post an update here later this afternoon or early evening once we get more info from the recon crew concerning 91L. I don’t think much will change with 99L today but if there is, I’ll certainly update that as well.

M. Sudduth 10:10 AM ET Aug 28

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Fernand bringing heavy rain to Mexico as rest of tropics lie dormant

Satellite image of Africa showing a distinct lack of deep convection or thunderstorm activity

Satellite image of Africa showing a distinct lack of deep convection or thunderstorm activity

TS Fernand was short-lived and thank goodness for that because it was well on its way to ramping up and in quick fashion. Fortunately, the Yucatan peninsula stalled its development until it reached the Bay of Campeche. Look what happened in just a half a day – it went from a tropical wave to a well developed tropical storm that had an eye-like feature at landfall. This goes to show how quickly things can change, especially for small tropical cyclones like Fernand.

The rain threat will persist for the next day or so as an abundance of deep tropical moisture is still streaming in to the coast of Mexico. Heavy rain is very much a hazard of tropical cyclones and should never be dismissed or downplayed. The storm is moving fairly slowly to the northwest and will take some time to clear out.

Meanwhile, the tropical Atlantic remains very quiet with no areas of interest noted right now.

I am puzzled by the fact that the GFS and EXMWF global models were seemingly sounding the horn for development in the deep tropics later this week. For the past few days, both models were fairly aggressive at showing a couple of tropical waves emerging from the coast of Africa and developing as they traveled west over the Atlantic. Now, both models have backed off considerably and show very little activity over the next five to ten days.

I see the signs that are supposed to equate to an increase in activity right about now: the favorable MJO pulse, time of the year we are in, warm sea surface temps, light wind shear, less dry air, etc. However, there seems to be something missing, some key factor that is keeping a lid on things in the tropics. Even the convection over Africa is very sparse at best. Normally this time of year we would see enormous clusters of thunderstorms over the continent, today, hardly anything at all.

In the eastern Pacific, there is no shortage of activity. There is an invest area, 95-E, that should go on to develop as it moves generally parallel to the Mexican coastline. Intensity guidance suggests it will remain weak and not reach hurricane strength. The proximity to the coast of Mexico will likely mean periods of heavy rain are in store as the system moves slowly over the coming days.

For now, there’s not much going on and for coastal residents all around the Atlantic Basin, this is great news. Unless something changes in the near-term, I don’t see any issues for the week ahead. It is looking quite possible now that we’ll end August without a single hurricane forming. While not unprecedented, it is rare for this to happen. We are getting quite late in the season with no hurricanes as of yet. If we go just long enough, who knows, maybe we will get by with a big fat zero. Anyone want to calculate the odds of that?

I’ll have more here tomorrow.

M. Sudduth 9am ET August 26

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Signs of change as we approach August

As we enter the last week of July and look ahead to early August, it appears that some changes are in store across the tropical Atlantic.

I think it is safe to say that most people know that hurricanes are a result of the build up of heat in the tropics. The warm oceans provide the fuel. However, warm water alone does not support tropical cyclones, there are several other factors involved. One of them is moisture in the mid-levels of the atmosphere. A dry or stable air layer will simply not allow the deep convection that drives tropical cyclones to develop, much less thrive. For the last couple of weeks or so, we have seen enormous areas of dry, dusty air (Saharan Air Layer) move off of Africa and spread west across the Atlantic. I mentioned this in a previous blog post. This phenomenon is typical for July in any year and usually abates by the time we get to August.

Right on cue, the SAL is beginning to weaken and move farther north, allowing the tropical waves that emerge from Africa to retain their energy longer, having a chance to develop more over the warm Atlantic.

In response to this change, several of the global computer models are beginning to hint at possible development over the next week off the coast of Africa. While I think it is still just a little bit too early and conditions are just not quite there yet, it is only a matter of time before we begin to see real signs of life out in the deep tropics.

Meanwhile, in the east Pacific, invest area 90-E has struggled somewhat since yesterday but could still become a tropical depression over the open waters of the Pacific. It will not pose any threat to land areas so even if it does develop, it won’t be an issue.

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Hurricanes Daniel and Emilia moving westward under strong high pressure

The east Pacific hurricane season continues to churn out the hurricanes. We now have Daniel and rapidly intensifying Emilia to track. Both systems are moving away from Mexico and out farther in to the Pacific. The reason is fairly simple: strong high pressure to the north, driving each hurricane westward due to the clock-wise flow. This is very similar to Ike in 2008 which moved generally westward from Africa all the way to Texas. It did so because strong high pressure, deeply entrenched in the atmosphere, pushed it along with no chance to turn north before landfall. Sometimes the pattern is just right and a tropical cyclone will move west for many days until it encounters land, cooler water or strong winds aloft to tear it apart.

In the case of Daniel, it will eventually feel the effects of much cooler Pacific water temps and gradually lose its punch. Folks in Hawaii should fare just fine as the remnants of Daniel track well to the south of the island chain.

Emilia will track a bit more WNW than west for a few days until it begins to weaken and be steered more by the low level easterly winds. Emilia poses no threat to land and likely never will.

In the Atlantic, all is quiet. This very typical for the first half of July when dry, stable air blasts off of Africa and in to the tropical Atlantic. I see nothing in the global computer models to suggest any development over the next week at least. So enjoy the hot weather as best you can- the hurricanes are nowhere to be found.

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