Atlantic Basin about to get quite busy

It was foreseen by people such as Dr. Michael Ventrice from WSI more than 9 days ago – the tropics were about to come to life. A strong wave of energy or convection was forecast to move out of the Pacific and in to the Atlantic, setting off the chance for development and now we are seeing that coming to pass.

The NHC is watching two areas for possible tropical storm formation over the coming days. One, invest area 99L, is off the coast of Africa while the other one is located in the Caribbean Sea. Both have potential for additional development but it is 99L that has the highest chance right now.

I take a look at these systems and a lot more in my latest video discussion which is posted below. I’ll have another in-depth discussion here tomorrow.

M. Sudduth 2pm ET August 3

Share

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

Share

No real concern about 99L any longer as we focus on other areas over the coming days

Atlantic tropical weather outlook map from the NHC showing the areas of interest and the current position of TS Gaston

Atlantic tropical weather outlook map from the NHC showing the areas of interest and the current position of TS Gaston

Wanted to post some thoughts on 99L this very late hour of Friday night/early Saturday morning. It’s been a long week and tonight I can sleep soundly and not wonder what the future model output will show for the storm that never was.

I also want to comment on the other areas that bear watching as we progress through the weekend. One thing is fairly clear to me: there are no hurricane threats looming so we have that going for us.

As it turned out, the environment just didn’t support the development of the tropical wave that garnered so much attention this past week. Invest area 99L as it become widely known as will just pass in to the Gulf of Mexico from the Florida Straits this weekend with little more than passing squalls. While I can’t say development chances are zero, in my opinion, the chance of this becoming a hurricane is as close to zero as one could ask for. It’s just not going to happen this time. Despite the HWRF model blowing it up run after run in to a formidable hurricane, upper level conditions and the lack of overall organization of the system should keep this a scenario only inside of the computer model’s world.

Now we have a couple of other areas to watch – one in the Gulf of Mexico, the other not far from Bermuda over the Atlantic. Neither system look to develop much in the coming days – part of the overall negative pattern we seem to be in right now. Even TS Gaston is struggling as of late but it is forecast by most of the global model guidance to bust through the shear and other limiting factors to finally become a classic open Atlantic hurricane. It too poses no threat to land and I don’t see it ever becoming an issue except for an increase in ocean swells depending on how strong it gets and how far west it tracks.

East Pacific tropical storm Madeline is one to watch if you live in or are planning a trip to Hawaii for next week

East Pacific tropical storm Madeline is one to watch if you live in or are planning a trip to Hawaii for next week

In the east Pacific, tropical storm Madeline is forecast to strengthen and become a hurricane as it moves in the general direction of Hawaii next week. Water temps in the region are running a little above normal so it’s possible that Madeline could make it to Hawaii as a tropical storm. It’s tough as heck to hit the Big Island from the east so we’ll see how this pans out. There is plenty of time to monitor the situation and react as needed as we know more about the track and intensity of this Pacific tropical storm.

Last but not least, I will be watching with keen interest as a new tropical wave emerges from Africa early next week. The GFS in particular has been very consistent in developing it right away and moving west for quite a while. The steering pattern that the GFS has been showing is one that could keep what ever might develop moving along just south of 20N latitude for several days at least. That being said, I do not see this being a threat to the Lesser Antilles, not in the modeling anyway. It’s early and it’s prime time for the Atlantic hurricane season and we know how quickly things can change. This next system will be something to keep an eye assuming the modeling is correct and it does in fact develop. Time will tell.

That’s it for now, time for some deep sleep and then more posts coming over the weekend.

M. Sudduth 12:35 AM ET Aug 27

Share

When 80% is not enough

Wednesday, August 17 at 2pm ET the National Hurricane Center issued the first outlook on what would become probably the most talked about area of interest (invest) in the history of mankind. That outlook began a process that kept scores of weather geeks, emergency managers, TV meteorologists, weather forecasting firms and the general public glued to their Internet-connected devices. From the get go it looked like this could be “the one”. It had potential to make it all the way across the Atlantic and possibly affect the United States after roaring through the Caribbean. And so here we are at the other side of that long journey and what became known as “99L” to millions of people will long be remembered for what it didn’t do: failed to develop.

As the process of tracking the tropical wave got underway, computer models were generally in agreement that the system would move westward at a fairly low latitude. However, it was clear early on that mid-level dry air, somewhat associated with the Saharan Air Layer (SAL), would be an inhibiting factor for development. Never the less, by early Saturday morning the 20th, it looked as though a tropical depression would form. Chances went from virtually nothing to 50% in just three days.

By Monday evening the 22nd, the probability increased to 60% and it looked as though a hurricane was possible for the southwest Atlantic Basin, maybe even close enough to Florida or the Carolinas to warrant concern. The social media hurricane machine was in full throttle mode with every expert (and non-expert) opinion you could imagine being thrown in to the mix. It was “invest 99L” overload and it would only get worse.

Leading the charge for development at first was the dynamic duo of the GFS and the ECMWF. Both seemed to latch on to 99L and make something of it. At first, it looked like a track towards Florida and then a turn north was likely. At times, the GFS had an enormous hurricane sitting not too far off the North Carolina coast, moving harmlessly out to sea in the longer term. It looked like this would be a close call but no guarantees yet for a landfall.

As the days went by, seemingly very slow considering we can watch the computer models come and go virtually 24 hours a day, things began to change. The GFS dropped the development almost completely while the ECMWF put memories of Katrina, Andrew and Betsy in our collective minds. It wasn’t just the Euro, the new and improved HWRF model, which is specifically designed to forecast tropical cyclones, showed similar forecasts of a hurricane headed towards south Florida and then turning west as it tracked south of a strong high pressure area over the mid-Atlantic. The hurricane world went in to full meltdown mode. It had been since before Twitter, Facebook as we know it, the iPhone and even the birth of One Direction that Florida had been hit by a hurricane. It was Tuesday, August 23 and 99L had a 70% chance of developing in to at least a tropical depression. The “H” word was bound for Florida.

To make matters worse, the ECMWF ramped up 99L to beast mode and sent it towards Louisiana, the LAST PLACE that needs a hurricane this season. Meanwhile, the GFS showed almost nothing at all. Just weak energy coming across and never really doing much. People were scoffing that if the Euro was right, congressional hearings needed to take place immediately to “fix the GFS!”. It was pure madness because, you know, the ECMWF nailed Sandy’s forecast from 8 days out. People were hung up on a hurricane from four years ago, forgetting the failures of even recent events like Erika last season and Fiona in 2010. Oh yeah, let me tell you about that one.

In 2010, we had Earl, headed for a possible landfall up the East Coast. Meanwhile, the ECMWF was advertising Fiona to be “the next Katrina”. A few in the weather business bit off on this and ran with it like the end times were coming. Earl was going to be a dud while Fiona would be a disaster of epic proportions. All the while, the GFS showed Earl doing exactly what it ended up doing: coming close to the NC Outer Banks then turning out to sea as a strong hurricane. As for Fiona, the GFS showed it as nothing more than a nuisance and that’s how it all turned out. GFS right, Euro wrong. Funny how few people remember that. I remember, trust me, I was on the Outer Banks where Earl brought 85 mph wind gusts to our anemometer that was set up next to Oregon Inlet.

By Wednesday morning, just 48 hours ago, the chance for 99L to develop made it to 80%. It looked like a sure thing now. I mean 80% is pretty good, right? In basketball an 80% free throw shooter is considered to be almost lethal from the line. You foul that player and you might as well put two points on the board. Eight times out of ten the shots go down.

But what happens when that player is in the title game and his team is down 1 with .90 seconds on the clock and he is fouled driving to the hoop? Everyone holds their breath as he lofts the first shot to tie the game. He misses. It’s stunning. The announcers balk about his percentage and how they can’t believe he missed. Must be the immense pressure. Time for try number two. He misses. No one gets the rebound and the clock expires. His team loses the National Championship for one simple reason: 80% is not enough. It’s not 100%. There was a 20% chance he missed either of those two shots. Now this is purely hypothetical but it makes my point. Sometimes high probability is mistaken for certainty.

In the case of 99L, it looks dead and gone now. The GFS, in its past few days of runs, turned out to be correct, for the most part. No hurricane coming for south Florida this weekend like the Euro showed. To be fair, the HWRF did as well and it busted big time. Instead, the Euro now has weak energy bringing possible heavy rain to portions of Florida. No hurricane in to Louisiana or elsewhere, just a strung out mess.

Odds of development over the next five days are down to 60%. Strong wind has all but beat the system in to oblivion. There is virtually no convection or thunderstorm activity with it and the USAF Hurricane Hunter crew has been grounded since there’s nothing there to investigate.

Sixty percent. Hmmmm. That’s not too high nor is it very low either. What is the reason behind this number? It’s because there is still a chance, apparently a 60% chance as of this writing, that 99L will develop some in the Gulf of Mexico. How could this be? The Euro “dropped it”. Well, the ever-excited HWRF sure didn’t and the GFS now shows limited development in a few days with some rather wacky tracks thrown in for good measure. To be honest, it’s giving me a headache to watch this day in and day out and all we have is an area of interest, even if fading to an area of blue skies.

I caution that while the gist of my post is aimed at pointing out the obvious, that anything short of 100% probability has a chance of falling short, it is also true that unless it’s zero, there’s still a chance. Even the 60% free throw shooter is sometimes the hero.

There is still some energy down in the region near the southeast Bahamas that might be able to survive long enough to warrant keeping an eye on. None of the computer models that show any development potential do so until later in the weekend – so let’s see what happens. Perhaps 80% was too high early on but 60% will be just enough for now.

We want to be able to trust the computer guidance to give us time to prepare if in fact something is going to develop. However, the public should understand probability and know the limitations of forecasts even in the relative short term. Most people don’t have time or interest to fully invest their energy in to making sense out of it all. I do my best and could not for the life of me understand why the GFS gave up on this system while the Euro did not. Sometimes you need to look out the window, so to speak, and view the actual weather and not just the predictions. The satellite presentation of 99L never really looked promising for development. It came close a couple of days ago but the reality was it didn’t have that “look”. So logic should have dictated that if it looks poor and one of the major global models insists on non-development, then maybe that’s why: because it won’t. It’s a simple concept and for now, it turned out to be right. Shear and lack of convection and overall organization has kept 99L from developing but it’s not necessarily over.

I think the next 48 hours will be all we need to know how this ends. If nothing happens by then and the wave of energy basically spreads out or dissipates completely, then we’re golden. Until that happens, it’s obviously prudent to keep an eye on things – just in case 60% is just enough to do what 80% could not.

I’ll have more in my daily video discussion posted here, to our app and on YouTube later this afternoon.

M. Sudduth 9AM ET Aug 26

Share

Model guidance duel continues as 99L tries to organize

Satellite image clearly showing that the low level center, weak as it may be, remains exposed due to strong upper level winds

Satellite image clearly showing that the low level center, weak as it may be, remains exposed due to strong upper level winds (click for full size)

The overnight runs of the various computer models did not really get us any closer to “knowing” the outcome of what becomes of 99L.

As it stands now, the tropical wave continues to slowly get better organized over the warm waters of the extreme southwest Atlantic – but I emphasize the word “slowly”. It seems that strong upper level winds are continuing over the system, preventing the thunderstorms from persisting and wrapping around the broad area of low pressure situated just north of eastern Hispaniola.

Despite the lack of organization, strong winds are being observed in the convection that itself is well removed from the low level center (poorly defined low level center). In addition, heavy rain is spreading over portions of Hispaniola and this is cause for great concern due to the risk of flash floods and mudslides. Remember, there are some fairly tall mountains in the region and tropical rain fall can lead to lethal flooding and tremendous damage.

The wave of low pressure is forecast to continue moving off to the west-northwest today and tomorrow, reaching the southeast Bahamas during that time frame. From there, it is likely to track through the Bahamas and toward Florida this weekend.

Early morning run of the HWRF model showing a strengthening hurricane in the eastern Gulf of Mexico in about 96 hours

Early morning run of the HWRF model showing a strengthening hurricane in the eastern Gulf of Mexico in about 96 hours (click for full size)

Now the tricky part: how strong does this system get – if at all? My answer: I honestly don’t know. The computer guidance is very confusing with the majority of the U.S. generated models, such as the GFS and the hurricane-specific HWRF model both showing little to no development, at least not in the short term. It is interesting to note that the HWRF, which stands for Hurricane Weather Research Forecast, is now indicating significant strengthening in the eastern Gulf of Mexico, around days 4 and 5. I am skeptical since that same model has had a very difficult time developing 99L much at all the past day or so.

On the other hand, consistency has been the rule for the much talked about ECMWF model or Euro. It has not strayed from its forecast of a possible hurricane impacting south Florida later this weekend. From there, it goes on to strengthen and make landfall up near the Big Bend area as a formidable hurricane. Needless to say, this is quite concerning but exactly how much stock do we put in to it? I just don’t know what to make of all this right now. On the one hand, the remarkable run to run track record of the Euro makes me think it could have the correct overall solution – that being a potential hurricane for some portion of Florida in the coming days. Conversely, the lack of development seen by the GFS and the waffling of the HWRF model for track and intensity makes me wonder: will anything happen at all?

ECMWF from the overnight run showing tropical storm conditions for the southern portion of Florida this weekend

ECMWF from the overnight run showing tropical storm conditions for the southern portion of Florida this weekend

All of this is not good for the public and the perception of how hurricane forecasting is “supposed” to be. Usually we don’t keep waiting and waiting just to see if a system will develop. The advantage, if you’re going to have to deal with a hurricane, is knowing it is coming in the first place. The “what if” scenario here is a little unsettling.

Let’s suppose that 99L does indeed wait until 24 hours before landfall in south Florida, assuming it does in fact take a path in that direction. If it were to quickly intensify over the very warm waters, how fast would it ramp up? Could it become a hurricane rapidly? Yes it could. We’ve seen it before but it’s been a while. Katrina in 2005 was on a fairly steady pace to strengthen as it approached SE Florida from the Bahamas but we at least knew it was a strong possibility well ahead of time. People will react better to a named storm or a hurricane headed their way than to a tropical wave. At least that’s my thought on the matter. This is a tough situation as the longer we wait, the less time there is to get ready if the need arises. While we would all like to wish that everyone along the coast was prepared anyway, we know the reality and it makes for quite the sitting duck in situations like this.

The afternoon runs of the various models (actually based on morning data) will be quite telling – or not. Questions about whether or not the GFS steps it up and develops 99L may be answered. What if it has the answer already and nothing much is going to happen to begin with? Maybe if the Euro suddenly shows little to no development we can at least say, ok, two major global models now show a low impact event. We will just have to wait and see. Either we know more or are stuck with dueling models once again.

I will post more here this afternoon including my daily video discussion.

M. Sudduth 8:50 AM ET Aug 25

Share