Crown Weather
Discussions

Invest 91-L Located Over The Eastern Tropical Atlantic: A tropical wave, which has now been designated Invest 91-L by the National Hurricane Center, has become a little more organized today. Latest satellite imagery indicates that the thunderstorm activity around Invest 91-L has become a little more organized and concentrated as compared to what it looked like yesterday. Even though Invest 91-L is a little more organized today, I do think that we are still a couple of days away from it becoming a tropical depression. We’ll get there, but it’s going to be a slow process.

Current analysis of environmental conditions reveals that Invest 91-L is still stuck in a narrow ribbon of low wind shear that is surrounded by strong wind shear to the north and to the south of this system. Because of these marginally favorable conditions, slow development is still expected for the next few days.

A look to the west of Invest 91-L shows that the environmental conditions become much more favorable for development west of about 45-50 West Longitude. This means that I think that we’ll really see the development occur by the time the wave reaches the area about 45-50 West Longitude late this weekend or early next week.

The latest model guidance are definitely trending towards a threat for the Leeward Islands, Virgin Islands and Puerto Rico late next week. All models seem to be pointing towards this threat & it is something that needs to be watched very, very closely if you are in the Leeward Islands, Virgin Islands and Puerto Rico.

That being said, the model guidance are still struggling with their forecasts as this disturbance is still in its formative stages. It might be a few more days before we see more consistency in the guidance, especially once this system develops into a depression and a tropical storm. Until then, unfortunately, we probably will continue to see fluctuating forecasts from the model guidance, so buyer beware when looking at them.

The GFS model has been wildly inconsistent with its forecasts of Invest 91-L for the last several days. For the last few runs, however, the GFS model has trended further south with its forecast of this system & now seems to be inline with the European model and the Google Deepmind AI models. The most recent 12Z forecast run of the GFS model now shows Invest 91-L impacting most of the Leeward Islands and the northern Windward Islands as a hurricane late next week & then directly impacting the Virgin Islands and Puerto Rico as a hurricane next weekend. From there, the GFS model has trended towards a higher threat now to the Bahamas, Florida & the Southeastern United States between about September 16 and September 18.

The Canadian model, on the other hand, is showing a curve to the northwest before it reaches the Lesser Antilles leading to no impacts for the eastern Caribbean.

The European model from last night’s 00Z run showed a pretty far south path bringing Invest 91-L right across the Leeward Islands as a hurricane around next Thursday followed by a track right across Puerto Rico and the Virgin Islands as a hurricane next weekend. Beyond this, the European model forecasts Invest 91-L to impact the Bahamas around September 16 to September 18.

Now, the most recent run of the European model from 12Z today shows a much weaker system (barely a depression) into the southern Leeward Islands and the Windward Islands around Wednesday of next week. This is followed by further weakening and dissipation in the eastern Caribbean. As I said, the models have been wildly inconsistent & just cannot be believed right now, until at least we have a fully formed system.

A look at the Google Deepmind AI models, they seem to show the same southerly type track that takes Invest 91-L right across the Lesser Antilles around Wednesday of next week. Interestingly though, the Deepmind model shows dissipation shortly thereafter with no other impacts forecast by this model.

As for the ensemble guidance – The GFS ensemble model guidance do show a different outcome from its operational deterministic counterpart. Most of the members show a further north track either near or north of the northern Leeward Islands, but they have shifted further south than previous model runs.

The European ensemble models are also different than the operational European model as a majority of the members show a track near the northern Leeward Islands & then a pass east of Puerto Rico and the Virgin Islands. There are a few members, however, that do show a track right across the central and southern Leeward Islands right into Puerto Rico and the Virgin Islands around Wednesday and Thursday of next week.

Here Are My Thoughts: As I mentioned near the start of this discussion, development into a depression or a tropical storm is still a couple of days away as my own analysis shows the environmental conditions being marginally favorable for development. Quicker development then looks possible by early next week when Invest 91-L moves past the 50 West Longitude line.

The southward trend in the guidance is certainly concerning, but it’s way too early to ring any alarm bells for the Lesser Antilles, the Virgin Islands and Puerto Rico. The reason why I say this is because the overall setup ahead of Invest 91-L is very complex with dry air issues possible, which could significantly impact this system. Also, the overall small size of Invest 91-L is giving the models fits because it is a lot harder for a model to resolve a small system than a larger system. There are times that the models completely miss resolving a tropical system because of its small size. This all leads to a very complicated and uncertain forecast with Invest 91-L.

My recommendation to those of you in the Leeward Islands, the Virgin Islands and Puerto Rico is to continue to monitor Invest 91-L very closely. Fortunately, there is a lot of time to watch this system as it’s still at least 6-7 days away from affecting the islands of the eastern Caribbean. Be aware though that there is at least the possibility of this system bringing impacts in terms of wind, rain and rough seas to the Leeward Islands, the Virgin Islands and Puerto Rico during the middle and later parts of next week.

Looking beyond this, it is way, way, way too soon to tell whether Invest 91-L will end up becoming a threat to the Bahamas, Florida or the East Coast of the United States. One thing that I will say with total confidence is that you should be ignoring those forecasts from the GFS model or earlier runs of the European model showing the hurricane strike on the Bahamas and the Southeast coast of the United States. These forecasts are some two weeks away and are oftentimes extreme outliers of what ends up happening in the end. Ignore the scary social media posts that are showing these model depictions.

It’s going to take about two weeks for Invest 91-L to make it all the way to the Bahamas and the US Southeast Coast & the weather pattern, to me, just doesn’t scream East Coast threat with this system. This weather pattern looks to consist of some sort of an upper level trough of low pressure near the East Coast of the US, which should turn this system to the northwest and north. Where this actually occurs in relation to the US coastline is an unknown right now because this is something that will not happen for another 8-10 days from now.

My recommendation for those of you in the Bahamas, Bermuda or along the US coastline from Florida to the Carolinas is to just keep an eye on this system. For now though, it’s nothing to get overly worried or stressed about.

The next tropical weather discussion will be issued on Friday.

Tropical Wave Located Over The Eastern Tropical Atlantic: Satellite imagery and analysis of the latest weather data today revealed that the tropical wave that’s located over the eastern tropical Atlantic along about 32 West Longitude is still pretty disorganized. A look at the satellite imagery shows that there is disorganized shower and thunderstorm activity with the wave and that the cloud structure seems to have a bit of curvature look to it. That said, there is no defined areas of low or mid-level circulation with this wave.

All-in-all, I think that this wave still has at least a couple of more days until it may start development.

Looking at the environmental conditions around and ahead of this wave reveals that this wave continues to move within a narrow ribbon of low wind shear with much stronger wind shear located just to the north and just to the south of where this wave is located. Because of this, I still think that the development of this wave will be slow to occur over the next few days.

Looking further west, the environmental conditions become more favorable for development west of about 45-50 West Longitude. This means that the development chances of this wave look to increase by the time the wave reaches the area about 45-50 West Longitude late this weekend or early next week.

As for the latest model guidance, they all do show some slow and gradual development by this weekend. That said, they’ve all been very inconsistent with their forecasts & have fluctuated wildly from run-run with both forecast track and forecast strength. This says to me that the forecast of this wave is highly uncertain & it may be a few more days until we get a better idea of where this system might go and how strong it might become.

The latest GFS model run now shows little or no development from this wave over the next week or so due to its forecast of no relaxation in the unfavorable conditions that seems to be affecting this wave right now. It does show a safe path well to the north and east of the Lesser Antilles. The GFS model then forecasts strengthening of this system by next weekend when it turns northward and heads towards Bermuda.

The latest European model forecast from its 06Z run now shows this wave becoming a rapidly strengthening hurricane by Monday and Tuesday of next week as it heads westward towards the Lesser Antilles. This is a big difference from last night’s 00Z European model run when it forecast this wave to strengthen some to perhaps a tropical storm by early next week & this run of the European model forecasts a direct impact on the Leeward Islands, Virgin Islands and Puerto Rico between Wednesday & Friday of next week as a weakening tropical storm. Again, be aware that all of the models have been very inconsistent, so buyer beware when looking at them.

As for the ensemble guidance – The GFS ensemble model guidance continues to cluster around a scenario that keeps this system north of the Lesser Antilles around Tuesday or Wednesday of next week. Beyond this, there are a fair number of ensemble members that show a very close brush or a direct impact with the island of Bermuda around next Friday or next Saturday.

The European ensemble model guidance seems to have trended both weaker and with more members showing a track keeping this system to the north of the Lesser Antilles during the second half of next week. That said, there are still about 30 percent of the ensemble members that do still show a direct impact on the far northeastern islands of the Caribbean.

Here Are My Thoughts: First, I think that we probably will not see any notable development during at least the next 2-3 days or so due to not very favorable environmental conditions. I think any development may wait to happen until this weekend and during the early part of next week when this system moves past the 50 West Longitude line.

Second, my recommendation for those of you in the eastern and especially the northeastern Caribbean is to monitor this system very closely. That said, this system is still at least 7-9 days away from affecting the islands of the eastern Caribbean, if it does at all. This means that we have more than plenty of time to keep an eye on this wave, no matter what it does.

Looking beyond this, it seems more likely than not that this system will probably be turned northward and then turned northeastward away from the US East Coast. The reason why this looks quite plausible is due to the fact that the weather pattern over the eastern United States is quite amplified with a persistent upper level trough & frequent fronts moving off of the East Coast. This should support the idea of anything moving towards the East Coast of the US to be turned safely well before it gets close.

There is, however, the potential for some sort of threat or even a direct impact to the island of Bermuda late next week into next weekend depending on how sharp the turn to the north and northeast is.

The bottom line is that this system could become some sort of a threat to the islands of the northeastern Caribbean, including the Leeward Islands, Virgin Islands and Puerto Rico around Wednesday or so of next week. There is, however, more than plenty of time to keep an eye on this wave.

---

Western Caribbean Or Bay Of Campeche Tropical Mischief Possible Later This Month: As I wrote in my evening update a couple of days ago, in addition to monitoring the tropical wave over the eastern Tropical Atlantic, I’m also keeping an eye on the western Caribbean for possible tropical development during the second half of this month.

There is some support in the model guidance that suggests there may be some increase in tropical development chances in the far western Caribbean and in the Bay of Campeche during the week of September 15. Those tropical development chances seem to really increase during the week of September 22 across the western Caribbean and across the Bay of Campeche & this is when I think we may really need to watch the western Caribbean for potential tropical development.

Supporting the idea of potential western Caribbean or Bay of Campeche tropical development are the expectations of an upward motion pulse of the Madden Julian Oscillation making its way into the Caribbean and the Atlantic by the second half of this month. This should cause increased stormy weather and a favorable background state for tropical development.

This all means that our eyes may really need to turn to the western Caribbean for the second half of this month & unfortunately, I think that anything that tries to form in the western and northwestern Caribbean will end up being pulled northward into the Gulf rather than being shunted westward into Central America. The reason why I think this is because of the persistent weather pattern of a Eastern US upper level trough, which if it remains in place would pull anything from the western Caribbean northward into the Gulf.

More updates on the possibility of Western Caribbean or Bay of Campeche development will be posted as needed.

The next tropical weather discussion will be issued on Friday.

Tropical Wave Located Over The Far Eastern Tropical Atlantic: Satellite imagery and analysis of weather today revealed that there is a tropical wave located over the far eastern Tropical Atlantic along about 20 West Longitude. This wave is producing disorganized shower and thunderstorm activity with no signs of organization, at this time.

Analysis of environmental conditions reveals that there is a ribbon of low wind shear located about where the wave is positioned. There is, however, some strong wind shear located just to the north and just to the south of where this wave is located. Because of this, I think that the development of this wave will be slow to occur throughout this week. The reason why I think this is because if this wave does begin to ramp up and develop, it’ll build into the area of stronger shear & weaken as it runs into this stronger shear.

Looking further west, the environmental conditions become favorable for development west of about 45 West Longitude. This means that the development chances of this wave look to increase by the time the wave reaches the area west of 45 West Longitude some this weekend.

The latest model guidance continues to show very differing ideas on what might occur with this wave, depending on how much it develops this week & whether it turns to the north or not.

The GFS model continues to be the most aggressive of the models and forecasts quick strengthening later this week leading to this wave to be a hurricane by this weekend over the central Tropical Atlantic. This quick strengthening leads to this system to be influenced by a mid-Atlantic upper level trough & thus is pulled far enough north to miss the Lesser Antilles next week. Ultimately, the latest GFS model forecasts this system to be a significant threat to Bermuda and then to Atlantic Canada in about 2 weeks from now. Last night’s 00Z run of the GFS model was “entertaining” as it showed a highly improbable scenario of a northwest moving hurricane hitting eastern New England in a couple of weeks from now. No tropical storm or hurricane has ever hit New England from a southeast direction. They usually hit from the south or southwest.

The European model now barely develops this wave over the next 7-10 days & shows this wave affecting the Leeward Islands as a robust wave next Wednesday.

As for the ensemble guidance – The GFS ensemble model guidance continues to cluster around a scenario that keeps this system north of the Lesser Antilles around Tuesday or Wednesday of next week. in about 10 days from now. That said, there are a few members that do forecast an impact on the northeastern Caribbean in about 10-11 days from now.

The European ensemble model guidance continues to be further south in its members tracks of this wave. About half of the ensemble members continue to show an impact to the northeastern Caribbean around next Wednesday. The other half of the members of the European ensembles show a track that keeps this system to the north of the Lesser Antilles.

Here Are My Thoughts: For now, I don’t think this wave is anything to be concerned about or worried about for the next several days. I do think that any development of this wave will be very slow to occur & may not occur until the very end of this week or this weekend when it approaches and passes through the 45 West Longitude line.

Now, for those of you in the eastern and especially the northeastern Caribbean, I would keep an eye on this wave, but for now, any impacts are still at least 8-9 days away. In fact, it’s quite possible that this wave will end up passing north of the northeastern Caribbean & not be a concern. That being said, this wave is located at a pretty low latitude and it would take quite a strong upper level trough to really pull this system northward & miss the eastern Caribbean. Because of this, I think that there’s a slightly better than 50-50 chance that this system will be impacting some part of the eastern Caribbean (highest risk is for the northeastern Caribbean islands) around Tuesday or Wednesday of next week.

Looking further west, the weather pattern over the eastern United States into the western North Atlantic may continue to consist of a persistent upper level trough of low pressure for the next 1 to 2 weeks or so. This will put up a shield, of sorts, & deflect any tropical systems approaching from the east and southeast for the next 1 to possibly 2 weeks. More than likely, this wave will probably be pulled out into the open Atlantic once it gets past the 60-65 West Longitude line. That said, the weather pattern around mid-September could shift into a more ridging pattern over the eastern US & if this happens, it could try to draw this system towards the Bahamas and US East Coast, but for now, that has a very, very low chance of occurring.

Bottom line is that this wave poses no threat to any land throughout this upcoming week right through this weekend. It’s then possible that this system could become some sort of a threat to the islands of the eastern and especially the northeastern Caribbean around Tuesday or Wednesday of next week. There is, however, more than plenty of time to keep an eye on this wave.

The next tropical weather discussion will be issued on Wednesday.

Tropical Wave Located Along The West Coast Of Africa: Even though the tropical Atlantic is very quiet for the peak of hurricane, I am keeping a very close eye on a tropical wave that has just left the coast of Africa. Buckle in because I think that we are going to be tracking this wave for many days to come & I also think that it is a wave that does need to be watched extremely closely.

Satellite imagery today reveals that this wave is producing some disorganized convection with part of the convection now over the far eastern Atlantic and other parts of the convection still over far western Africa. This wave should fully immerse itself over the far eastern tropical Atlantic by Monday.

It is expected that this wave will head westward across the eastern tropical Atlantic over the next few days reaching the central tropical Atlantic by the very end of this coming week. Analysis of environmental conditions ahead of this wave reveals that the wind shear values are favorable for at least slow development this coming week. This means that I don’t think this wave is going away anytime soon. Also, the steering winds across the eastern and central tropical Atlantic should guide this wave in a general westerly direction across the eastern and then the central tropical Atlantic throughout this upcoming week.

A look at the latest model guidance forecasts reveals that there are trends in all of the model guidance that suggest this wave will eventually develop and at some point may become a hurricane. The guidance, however, disagrees wildly on where this wave may eventually go & how strong it might get.

The GFS model forecasts pretty quick strengthening by late this week when this wave is still over the eastern Atlantic. This leads to a forecast of this system turning out into the open Atlantic well before it reaches the eastern Caribbean. In fact, the GFS model forecasts this turn to occur at around 45 West Longitude. One thing to note about the GFS model is that it has a notorious bias of turning storms to the north too quickly and in the end, these storms end up tracking much further west than what the GFS model showed.

The Canadian model shows slower development throughout this upcoming week as this wave heads westward. The Canadian model does suggest this wave might gain just enough latitude to keep it to the north and east of the northeastern Caribbean in about 10-12 days from now.

The European model also suggests slow development from this wave and in fact, really doesn’t forecast it to significantly strengthen until it’s passing just north of the Lesser Antilles next Wednesday (September 10). Ultimately, the European model forecasts this wave to be a strong hurricane that passes just east of Bermuda around September 14.

As for the ensemble guidance – The GFS ensemble model guidance seems to be clustering on most members showing an eventual track that takes this system north of the Lesser Antilles in about 10 days from now. That said, there are a few members that do forecast an impact on the northeastern Caribbean in about 10-11 days from now.

The European ensemble model guidance looks a lot more aggressive and much further west in terms of a potential track of this wave. It seems that about half of the members that show an impact to the northeastern Caribbean in about 8-10 days from now. The other half of the members of the European ensembles show a track that keeps this system to the north of the Lesser Antilles.

Here Are My Thoughts: As I mentioned at the start of this discussion, I do think that we are going to be watching and tracking this wave for quite a while. In fact, we are still at least 8-10 days away from this wave affecting the eastern and northeastern Caribbean, if it does at all.

I do think that we are probably going to see very slow development of this wave throughout this upcoming week. This is due to the fact that the conditions across the eastern Tropical Atlantic are marginally favorable for development.

The weather pattern this upcoming week across the Atlantic is going to consist of a large upper level trough centered along about 50 West Longitude. This means that this wave will be impacted by strong shear at times, limiting development throughout this upcoming week. Once this wave passes about 55 West Longitude or so, it’ll begin to move into a much more favorable environment, but this will not happen for about another week from now.

My takeaway when looking at the data is that I think that we’re looking at a wave that may be able to stay pretty far south in latitude. Because of this, there’s the very real potential for this wave to travel fairly far to the west & potentially be more of a threat than Erin ever was. Also, the conditions across the eastern and central tropical Atlantic aren’t all that favorable for development and because of this, this wave should stay weak & not be influenced as much by that trough leading to more of a westward track than definitely what the GFS model suggests and even what the European model suggests.

For now though, this wave poses no threat to any land throughout this upcoming week. It’s possible that this system could become some sort of a threat to the islands of the northeastern Caribbean in about 7-9 days from now. That said, there is more than plenty of time to keep an eye on this system.

Could this system eventually threaten or impact areas further west towards the Bahamas, Florida & the US East Coast? It’s possible, but it’s obviously way, way too soon to even start looking that far out.

I will be keeping a very close eye on the progress of this wave, no matter what it does. Many more updates on this wave will be posted in the coming days.

The next tropical weather discussion will be issued on Monday.

Tropical Wave Moving Off Of Africa On Sunday Has A Chance To Develop Next Week As It Heads Westward Across The Eastern & Central Tropical Atlantic: It is expected that a tropical wave will push off of the west coast of Africa in a couple of days from now and then head westward across the eastern and then the central Tropical Atlantic during next week. There is some possibility that this tropical wave could try to develop into a tropical system as it heads westward next week.

A look at the model guidance reveals that while models such as the GFS model, the Canadian model and the European model do show this system development, they forecast very different scenarios with this system.

The GFS model, on one hand, forecasts that this system will strengthen significantly next week into probably a hurricane that ends up turning out into the open Atlantic along about 35-40 West Longitude.

The Canadian model forecasts minimal development near the Cape Verde Islands, however, that is short-lived and this wave falls apart as it heads westward and never develops again.

The European model forecasts some development from this wave as it heads across the eastern Tropical Atlantic during the middle part of next week. Beyond this, the European model forecasts little additional development and ends up forecasting this wave to fall apart well east of the Lesser Antilles next weekend.

A look at the ensemble guidance reveals that while there is some decent support for some development of a depression or a low-end tropical storm in the eastern Tropical Atlantic next week, its development is fairly short-lived and none of the ensemble members show any sort of threat to the Lesser Antilles or the eastern Caribbean.

Here Are My Thoughts: While I do think that some development of the this wave is possible next week as it heads westward across the eastern Tropical Atlantic, I think the chances of any significant development are very low. The reason why I think this is because the overall background state is quite hostile towards any sort of development.

This means that a short-lived depression or low-end tropical storm over the eastern Tropical Atlantic seems possible that ends up weakening and dissipating well before it reaches the Lesser Antilles.

There is nothing in the data, at this time, that supports any sort of a threat from this wave.

---

Frontal System Along East Coast Of The US Should Be Watched For Tropical Mischief Next Week: One thing that I continue to keep an eye on is the possibility of some sort of tropical mischief occurring near the tail end of the frontal boundary that’s been draped offshore of the Southeast coast of the United States. Old fronts like this can be a source of tropical development as low pressures tend to spin up near the frontal convergence & then try to develop into a tropical system.

The model guidance, as a whole, seems somewhat onboard with the possibility of in-close development near the US Southeast coast during the first half of next week. That said, as usual, there are differences in the model guidance on what occurs with any low pressure system that develops.

The GFS model shows a very strung out and weak low pressure system that never gets its act together offshore of the East Coast between Sunday and Tuesday.

The Canadian model also shows very little in the way of development from any weak low pressure systems that ride along the front offshore of the US East Coast next week.

The European model also shows some weak low pressure systems that never gets their act together off of the East Coast of the US next week.

The story looks much different when we look at the ensemble guidance as they seem a little more interested in showing tropical mischief along this front.

The GFS ensemble model guidance shows a clustering of members showing development just north of the Bahamas early next week. The members that do show development forecast any system will take off to the northeast and stay just offshore of the East Coast and head for Atlantic Canada.

A look at the European ensemble model guidance reveals that there are a few members that show development just north of the Bahamas around Tuesday or Wednesday with the members that do show development forecasting a track taking this system to the northeast just offshore of the East Coast and towards Atlantic Canada. It should be noted that the European ensemble model guidance does show about a 20-25 percent chance for development during the first half of next week just north of the Bahamas.

Here Are My Thoughts: While I’m going to be keeping a very close eye on whatever low pressure system that tries to form along the front, I think that the chances of tropical development are fairly low, as of right now.

More likely than not, any low pressure systems should remain non-tropical. That being said, the ocean waters in the area north of the Bahamas are very warm & it wouldn’t take much for a low pressure system to become a tropical system, especially if it hangs around and festers. All-in-all, I’m not ruling out tropical mischief near the Southeast coast of the United States next week, but I also think the chances right now are low.

The next tropical weather discussion will be issued on Sunday.

Tropical Storm Fernand: Fernand seems to be trying to strengthen today as satellite data reveals that the storm has maximum winds of 50 mph. This burst of strengthening looks to not last much longer as it will be moving into progressively colder ocean waters over the next couple of days. This means that Fernand will likely weaken and become post-tropical as we get into Thursday.

Additionally, Fernand will continue to head out into the open Atlantic & continue to not be a concern to any land.

---

Elsewhere Across The Atlantic, Caribbean & Gulf: The rest of the Atlantic Basin is unusually very quiet for late August. It appears that these quiet conditions will last right into the first week of September.

The reason why the Atlantic is quiet is due to widespread unfavorable conditions across the Atlantic as a downward pulse of the Madden Julian Oscillation makes its way across the Atlantic.

Does this mean that there is nothing to keep an eye on? Nope.

One thing that I continue to keep an eye on is a frontal boundary that’s draped from off of the East Coast of the United States southwestward through the Florida Peninsula into the southern Gulf. These decaying fronts can sometimes be a source of tropical development as areas of low pressure form near the tail end of the front, break off from the front and then develop into a tropical system.

While there is no areas of low pressure to watch right now, the various model guidance continue to indicate that a couple of low pressure systems may form in the area from just north of the Bahamas westward to the eastern Gulf and then try to head up the East Coast of the United States late this weekend into early next week. The guidance does seem to insist that these low pressure systems will be non-tropical in nature & not amount to much.

What these low pressure systems might end up doing is to bring some enhanced thunderstorm activity to much of the Florida Peninsula during this weekend into the first half of next week. These low pressure systems may also bring some locally squally weather, areas of showers & some gusty onshore winds to the immediate coastal areas of the Carolinas early next week.

No matter what these low pressure systems do, I will be keeping an eye on them, just in case.

One other item that I’m watching is a tropical wave that’s located over western Africa. This wave is expected to push off of the coast of Africa into the far eastern Atlantic by late this week and this weekend. The reason why I’m mentioning it is because some of the weather models are showing it trying to develop as it heads westward across the Atlantic during next week. In fact, the European ensemble guidance is giving this wave about a 30-40 percent chance of development as it heads westward across the eastern and central Tropical Atlantic.

This wave could be something to keep an eye on next week, although, we will have a long time to really watch it & because of that, I’m not overly concerned about it. It should be noted that the overall conditions across the Atlantic next week does look unfavorable and because of that, this wave will probably struggle to develop and any development should be slow to occur.

---

Activity Across The Atlantic Looks To Pick Up Again By Mid-September: It does look like conditions will become largely favorable again for development across the Atlantic by about the September 10-15 time period as a new upward motion pulse of the Madden Julian Oscillation makes its way into the Atlantic & I do think that activity will pick up in earnest by about mid-September. In fact, I fully expect that the second half of September and the first half of October could be quite active across the Atlantic, Caribbean and Gulf.

The longer range model guidance seems to support the idea of an active second half of September with the European model forecasting almost double the average amount of activity by the week of September 22.

So, let’s all try to enjoy the rare late August and early September breather in terms of tropical activity because, unfortunately, hurricane season is far from being over. In fact, I think that a very active backloaded season is very much likely.

The next tropical weather discussion will be issued on Friday.

Tropical Storm Fernand: There’s not much to say about Tropical Storm Fernand, except that it is headed out into the open Atlantic and likely doesn’t have much longer until it begins to weaken.

Fernand is headed on a north-northeasterly track today and is likely to turn more to the northeast and east-northeast over the next couple of days. This track will lead the storm safely out into the open Atlantic.

Additionally, it is likely that Fernand will run headlong into an area of very strong wind shear by late today or Tuesday. Because of this, its window for any sort of strengthening is about to be closed & I expect that Fernand will begin weakening by Tuesday and become a non-entity by Wednesday.

Fernand, we hardly knew ye.

---

Invest 99-L Located Over The Eastern Caribbean: After looking quite robust all weekend long, Invest 99-L has completely fallen apart today due to low-level divergence and strong westerly wind shear.

It now looks highly unlikely that much, if anything will come from Invest 99-L as it heads westward across the Caribbean this week. This westward track will lead this disturbance to move inland into Central America by Wednesday or Thursday.

All model guidance have backed way off on showing any sort of development with Invest 99-L & I have to agree with this.

---

Coastal Storm Possible For Early Next Week Along The US East Coast: Pretty much the only thing to really keep an eye on over the next week or so is going to be the possibility of some sort of coastal storm forming near the Southeast coast of the United States around next Monday and then heads northward along the East Coast of the US as we get into next Tuesday and Wednesday.

Both the GFS and European models do show this potential coastal storm, which in all likelihood will probably stay non-tropical in nature. That said, it’s quite possible it could try to become some sort of hybrid storm that has both non-tropical and tropical features, but is never named.

What this coastal storm may end up doing is bring a few days of squally, rainy weather, along with gusty onshore winds to much of the East Coast of the United States, from coastal Georgia through the coastal Carolinas up to New England during the first half of next week.

I’ll keep an eye on this coastal storm possibility, in case it does trend towards being more tropical in nature.

---

The Rest Of The Atlantic Will Take A Snooze For A While: It appears that the rest of the Atlantic will go to sleep for the rest of this month. This snoozing of the tropics looks to last into the first part of September.

The overall conditions across the Atlantic are expected to be unfavorable for activity across the tropical Atlantic for at least the next one to two weeks. So, we are probably looking at about 10 to possibly 14 days without much going on across the Atlantic.

Does this mean Hurricane Season is over?? ABSOLUTELY NOT!!

It looks as if by about September 10th or so that a new upward motion pulse of the Madden Julian Oscillation will make its way around into the Atlantic & this is when things may start picking up again. In fact, I suspect that we could see an active second half of September and first half of October across the Atlantic, Caribbean and Gulf making another back-loaded season quite possible.

So we can enjoy the rare late August and early September break in tropical activity before things get more active again.

The next tropical weather discussion will be issued on Wednesday.

Invest 90-L Located About 500 Miles To The South-Southeast Of Bermuda: Satellite imagery today indicated that Invest 90-L has become more organized with concentated thunderstorm activity noted. Satellite wind data also indicates that Invest 90-L has winds of up to gale-force associated with it & it seems the low-level circulation is a little stretched out.

All indications seem to point towards Invest 90-L becoming our next tropical depression by this afternoon or this evening. Additionally, it also looks very likely that this system will strengthen into Tropical Storm Fernand by sometime on Sunday.

Invest 90-L is heading in a northerly direction today & it looks likely that this northerly path will continue over the next few days. Because of this, it looks most likely that this system will pass a couple of hundred miles or so to the east of Bermuda on Sunday night into Monday.

This means that the island of Bermuda may see some fringe effects from this system, on the order of some gusty winds and rough seas during Sunday into Monday.

Looking beyond this, it is expected that Invest 90-L will head out into the open Atlantic during next week with no effects expected to any land areas.

Model Track Forecast:

Satellite Imagery:

---

Invest 99-L Located About 800 Miles To The East Of The Windward Islands: I also continue to keep close tabs on what’s going on with Invest 99-L, which is located to the east of the Windward Islands.

Satellite imagery today indicates that the shower and thunderstorm activity associated with Invest 99-L is rather scattered & disorganized with no signs of increased organization right now.

The reason for the disorganization and scattered look of the convection with Invest 99-L is due to some strong northerly wind shear impacting this system right now. It is expected that this strong wind shear will continue to impact Invest 99-L over the next couple of days or so.

Invest 99-L is also expected to head in a westerly direction and move across the Windward Islands on Sunday night. This means that some squalls of locally heavy rain, thunderstorms and gusty winds can be expected across the Windward Islands, Barbados, Trinidad and Tobago from late Sunday into Monday.

As we get into next week, it is expected that this disturbance will move pretty quickly westward across the Caribbean, potentially reaching Central America late next week. The track model consensus and a majority of the ensemble guidance seems to suggest Invest 99-L will ultimately bury itself into Central America or just head for the eastern Pacific. That said, there are a couple of straggler ensemble members that forecast a turn northward into the northwestern Caribbean and towards the eastern Gulf in a week from now. It seems these few ensemble members that are showing this seem to show the eastern US upper level trough being strong enough to be able to pull Invest 99-L out of the Caribbean.

It should also be noted that the ICON model has been fairly consistent with its forecast of showing Invest 99-L curving to the northwest once it reaches the western Caribbean late next week putting this system near the Yucatan Channel by next Saturday. Also, a look at the upper air forecast for next Saturday from the ICON model suggests anything that makes it into the Yucatan Channel would be pulled towards the eastern Gulf, the Florida Peninsula and possibly right up the East Coast of the United States.

I want to point out that none of the other models really show this scenario and right now the ICON model is the lone one showing this. We will need to see if the other models start showing what the ICON model is forecasting or if the ICON model is completely wrong and caves to the other models.

For now, I do think that we are probably going to end up seeing Invest 99-L track straight into Central America late next week as possibly a tropical storm. I will be keeping a very close eye on the data, in case we do see a system getting pulled out of the Caribbean instead, like what the ICON model is suggesting.

Model Track Forecast:

Satellite Imagery:

The next tropical weather discussion will be issued on Monday.

Hurricane Erin: Erin is making its transformation from a hurricane to a large and powerful non-tropical storm system. I expect that this transformation will be complete by tonight.

Erin is also now heading into the open Atlantic and will continue to pass well south of Nova Scotia this afternoon and will then pass well south of Newfoundland tonight.

Even though Erin is racing away from the US East Coast and Atlantic Canada, rough surf and rip currents will continue to impact the East Coast of the United States, Bermuda and Atlantic Canada through this weekend. Anyone headed to the beach this weekend along the US East Coast are strongly advised to stay out of the water.

This will be the last update on Erin.

---

Invest 90-L Located To The Northeast Of The Northern Leeward Islands: An area of disturbed weather that is located to the northeast of the northern Leeward Islands is lacking much in the way of deep convection today.

Invest 90-L is expected to gradually develop during this weekend as it heads northwestward and then northward. It’s possible that this development will lead to Invest 90-L becoming a depression and then a tropical storm during this weekend or early next week.

A ridge of high pressure located to the west of the Azores will steer Invest 90-L northward & most model guidance seems to suggest that this system will pass to the east of Bermuda on about Monday, but it could be a close pass.

My recommendation to those of you on the island of Bermuda is to keep an eye on Invest 90-L throughout this weekend. I do not foresee this disturbance becoming very strong like what Erin just did. That said, this system could be a tropical storm when it passes just east of Bermuda on Monday.

Model Track Forecast:

Satellite Imagery:

---

Invest 99-L Located Halfway Between The Windward Islands & The Coast Of Africa: I am going to be closely watching the disturbance located about halfway between the Windward Islands and the coast of Africa as it may not go away quietly.

Satellite imagery today reveals that the convection around Invest 99-L is disorganized, however, it seems that this disturbance does seem to have a small circulation near about 10-11 North Latitude.

One thing that you can say about this disturbance is that it is tenacious & is going against most of the model guidance, which has insisted that it will fall apart and dissipate. In fact, this disturbance has been outperforming the models thus far & because of this, it’s possible we could see model guidance begin to play catch-up.

That said, analysis of environmental conditions reveals that there is 20-30 knots of wind shear now affecting Invest 99-L. Also, there is an area of up to 30 knots of wind shear located just east of the islands. We are going to have to see how this disturbance reacts to these unfavorable conditions & whether it does finally succumb and fall apart.

I do want to make a mention that it’s possible that Invest 99-L could sneak underneath the strongest of the wind shear & survive the trip into the Caribbean. If it does survive making it into the Caribbean, it could find a much more favorable environment for development over the central and western Caribbean.

Interestingly, the most recent run of the ICON model now shows Invest 99-L trying to organize as it moves through the Windward Islands on Monday & then strengthen into a tropical storm and maybe even a hurricane in the western Caribbean late next week. None of the other models or their ensemble counterparts forecast development from Invest 99-L. So, we will need to see if the other models catch up with what the ICON model is showing or if the ICON model is completely wrong with its forecast.

For now, those of you in the Windward Islands, Barbados, Trinidad and Tobago should keep an eye on this disturbance, just in case. Right now, it seems that most likely this disturbance will bring squally weather to the Windward Islands, Barbados, Trinidad and Tobago during the day on Sunday night and Monday.

Beyond this, I most certainly will be watching the progress of Invest 99-L when it moves from east to west across the Caribbean next week. Right now, I think that there is a small chance that it will become something substantial in the western Caribbean & because of this, it is something that needs to be watched, just in case.

Model Track Forecast:

Satellite Imagery:

---

In-Close Tropical Development Possible By Early September: Finally, there is the outside chance that we could see some sort of tropical development occur near the southeast coast of the United States right at the start of September.

All indications seem to point towards a strong upper level trough of low pressure pushing into the eastern United States during the second half of next week. As this trough begins to lift out next weekend, it could leave behind a piece of energy near the southeast coast of the United States.

There’s the small possibility that this piece of energy could evolve into a tropical system during the first few days of September somewhere between the southeast coast of the United States and the Mid-Atlantic coast. At this point, there’s a very low chance that this will actually happen, but given what the weather pattern looks like in terms of producing a tropical system at the tail end of a trough, it’s something that will need to be watched, just in case.

The next tropical weather discussion will be issued on Saturday.

Hurricane Erin: Erin is a very large hurricane with its tropical storm force winds extending out almost 500 miles across.

Latest reconnaissance aircraft are reporting that Erin has weakened a bit and is now about a 100 mph hurricane and the hurricane is now heading in a northeasterly direction away from the East Coast of the United States.

Even though Erin is moving away from the US East Coast, it is still producing coastal flooding along the North Carolina and Virginia coastlines and in fact the worst of the coastal flooding can be expected with this evening’s high tide. This coastal flooding threat is then expected to last into Friday along the North Carolina and Virginia coastlines.

For this evening’s high tide, it is expected that around 4 feet of coastal flooding can be expected on the Outer Banks of North Carolina and around the Virginia Beach area. This flooding will include compounding flooding and significant beach erosion due to both the high tide & the large and battering waves being produced by Erin.

Elsewhere, extremely rough surf and life threatening rip currents can be expected throughout the rest of this week into this weekend along much of the East Coast of the United States, across Atlantic Canada and on the island of Bermuda. You will be risking your life if you go swimming in the ocean over the next few days, please do not do it!!

Very gusty winds are expected to continue through this afternoon along the Virginia coast with gusty winds of up to 40-45 mph expected along the rest of the Mid-Atlantic coast into areas around Cape Cod, Martha’s Vineyard and Nantucket through Friday.

Gusty winds are also expected on the island of Bermuda this afternoon into Friday. As for Atlantic Canada, gusty winds are likely along the coast of Nova Scotia during the day on Friday and on the Avalon Peninsula of Newfoundland during the day on Saturday.

Forecast Impacts:
Wind:

Storm Surge:

Model Track Forecast:

Satellite Imagery:

---

Invest 90-L Located A Few Hundred Miles To The East Of The Leeward Islands: A fairly robust tropical disturbance, just designated Invest 90-L by the National Hurricane Center, is beginning its approach to the Leeward Islands.

Satellite imagery today reveals that there is some fairly concentrated convection occurring with Invest 90-L and the overall environmental conditions are favorable for organization and development over the next few days.

A look at the wind shear values around Invest 90-L reveals that the disturbance is embedded in a ribbon of low wind shear and conditions, overall, seem favorable for gradual development.

It looks likely that Invest 90-L will head in a northwesterly direction and because of this a majority of this disturbance will miss much of the Leeward Islands.

As for impacts to the Leeward Islands, Virgin Islands and Virgin Islands, it appears that this disturbance will bring some squally weather with locally heavy rain beginning on Friday and continuing through Saturday. The northernmost Leeward Islands and the British Virgin Islands will probably see the majority of the squalls as Invest 90-L passes just east of the islands.

Further down the road, it looks likely that Invest 90-L will head nearly due north and likely will develop into a tropical storm later this weekend into next week. Most guidance seems to suggest that this system should pass very near Bermuda around Tuesday and because of this, I urge those of you on the island of Bermuda to closely monitor the progress of this system.

Model Track Forecast:

Satellite Imagery:

---

Invest 99-L Located Over The Eastern Tropical Atlantic: Next up is Invest 99-L, which continues to be a robust looking tropical disturbance located over the eastern tropical Atlantic near about 36 West Longitude. Even though Invest 99-L looks quite robust, it just isn’t quite organized enough to be considered a tropical depression.

It is expected that Invest 99-L will head in a westerly direction over the next few days. Conditions for development become highly unfavorable west of 45 West Longitude due to a wall of strong wind shear. Once Invest 99-L hits this strong wind shear on Saturday, it will end any chances for organization or development.

Even though it looks unlikely that Invest 99-L will develop due to that strong wind shear, it will still continue heading in a westerly direction eventually reaching the southern Caribbean by the second half of next week. It is always a good idea to keep an eye on any disturbances moving into the Caribbean this time of year as disturbances, that once were considered dead, can make a rebound and develop.

It should be noted that there are a few ensemble members that do show some sort of development from probably Invest 99-L next weekend near the western Caribbean. That said, most of the ensemble models show no development at all from Invest 99-L.

In any case, this disturbance will be watched closely, no matter what it does.

Model Track Forecast:

Satellite Imagery:

The next tropical weather discussion will be issued on Friday.