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


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


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


Recon crew finds 99L not organized enough to be TD or TS yet

Visible satellite image showing a fairly disorganized tropical wave moving through the NE Caribbean Sea

Visible satellite image showing a fairly disorganized tropical wave moving through the NE Caribbean Sea

The value of the Hurricane Hunters is priceless. Their work and dedication is without equal in the weather world. Today, they proved it again with the flight in to invest area 99L. The data indicates that while the overall structure of the tropical wave has improved some, it’s not quite enough to name it a depression or a tropical storm.

Instead, we have a broad area of lower air pressure and plenty of general turning in the cloud motion. However, there is some fairly strong wind blowing over the top of the system and this is injecting dry mid-level air while also pushing any deep thunderstorms away from the weak low level center.

We can see this in the satellite image I have included here. Notice that the clouds are not symmetric in appearance but rather pushed off to the south and southeast. While there is clearly a weak circulation nearing Puerto Rico, it has yet to completely close off and become well defined. It may take another day before that happens which is generally what the models that develop this system indicate.

So for now, we still have a tropical wave but it is bringing with it strong winds and periods of heavy rain for portions of the islands of the NE Caribbean Sea. This will continue to spread WNW towards the Turks and Caicos and eventually the southeast Bahamas.

For what it’s worth, the latest GFS model run indicates once again that 99L will remain a weak system and never really impacts Florida. I do not understand why this is the solution the model is coming up with but it cannot be dismissed completely. We just don’t know – despite the insistence of the very reliable ECMWF or Euro model that this will become a hurricane and enter the Gulf of Mexico. Once I get a look at the latest output from this morning’s ECMWF run, I will post an update here, followed by a thorough discussion in my afternoon video blog. If you have our app, Hurricane Impact, be sure to check the video section later today for that update.

M. Sudduth 1pm ET Aug 24


Is Florida’s hurricane drought about to come to an end?

One look at the upper ocean heat content for the western Atlantic Basin and you can see why I am concerned for the Bahamas and Florida over the coming days.

One look at the upper ocean heat content for the western Atlantic Basin and you can see why I am concerned for the Bahamas and Florida over the coming days.

The past few days have been very tedious in terms of tracking invest area 99L and what it may or may not do over the coming days. Unfortunately, tedious may be traded in for anxious and stressful from here on out as it looks like we could be facing a potential hurricane threat for late in the weekend.

Before any concern arises for Florida, the system is first impacting portions of the northeast Caribbean islands with heavy rain and gusty winds. All of this mess will spread westward towards Puerto Rico and eastern Hispaniola later today through tomorrow. The potential for very heavy rain which could induce flooding is certainly there and needs to be considered as a serious threat.

As I type this blog post, the Hurricane Hunters are about to head out in to the broad area of low pressure to determine what its status is. There is a chance we will have a tropical depression by later today but overall, I think the organizational process will continue to be slow and steady.

The dry air we have heard so much about is likely going to be mixed out and the convective process will take over – meaning we will see sustained thunderstorm activity develop along with more curved banding. This indicates strengthening but also better internal structure which leads to even more strengthening. It is only a matter of time until we have a tropical storm to track and it looks to be headed towards the Bahamas as the week comes to an end.

This brings me to the possible impacts to the Bahamas and Florida there after. Assuming the system goes on to develop as most of the modeling now indicates, it will be a matter of how strong it becomes as it moves west-northwest and then bends back to the west. This is VERY important as history shows us that when tropical cyclones (tropical storms and hurricanes) bend westward, south of a strong ridge of high pressure in the atmosphere, that they strengthen, usually quickly. It all has to do with lining everything up under almost ideal conditions. Many hurricanes have done this in the past and in the general vicinity that this system would be in over the weekend. As such, the potential is there for south Florida to experience a hurricane before all is said and done. How strong and exactly where is hard to say right now. Water temps are plenty warm and the models are suggesting a favorable environment for intensification. We need to watch this very closely – it’s been more than a decade since the last hurricane affected the state directly. Preparedness will be critical, especially if we see a period of rapid strengthening. I am putting the region on notice, you had best be ready! We have a few days to go still before we know enough to say for sure what will happen but by then, it could be too late to react properly and no one needs to be in panic mode. Use this time to make sure you have a plan in place and be able to enact it should the need arise this weekend.

Unfortunately, the overnight models, namely the ECMWF or Euro, have come around to suggesting a track towards the west in to the southeast Gulf of Mexico early next week. This would give the would-be hurricane ample fuel and time to strengthen further. This is beyond the 5 day time frame so speculating on where it might end up is pointless right now. I know people want answers as soon as they can get them but it’s just too tough to make any definitive call at the moment. Needless to say, residents along the Gulf Coast from Texas to the Florida panhandle should stay on top of this and be ready in case it comes their way. We will have time to dissect the possibilities later on as more data comes in and the track and intensity becomes clearer.

To give you an idea of how seriously I am taking this situation, I am making plans now to pack up my gear and head to south Florida as early as Friday morning. With the potential for a hurricane crossing the region, it warrants a field mission to the area. I will talk more about my plans for Florida and a potential Gulf Coast landfall in future blog posts. It’s been a while since a full-throttle hurricane took aim at the United States. While the jury is still out on just how strong 99L could become, I am not leaving anything to chance. The technological firepower that I have in my possession is stunning. So much has changed since a decade ago and even the past five years. I’ll keep you posted on my plans and what kind of information to expect as I travel south for what could be a break in the streak of no hurricanes for Florida. As they say, stay tuned but let me add, be ready! Even if this does not pan out, it’s still very much hurricane season and we have a long way to go. Luck favors the prepared – always.

M. Sudduth 10:15 AM ET Aug 24