10 day outlook

BBT

Senior Insider
The Tropical Atlantic, Caribbean & Gulf Of Mexico Is Expected To Be Quiet For At Least The Next Week To 10 Days; Period From Early-Mid August To Mid October Could Be Fairly Active In Terms Of Tropical Storm/Hurricane Threats For The Far Northeastern Caribbean, The Bahamas & Along The US East Coast From Eastern Florida To Southern New England


The Tropical Atlantic, Caribbean & Gulf Of Mexico Is Expected To Be Quiet For At Least The Next Week To 10 Days: It appears that things will be quiet across much of the Atlantic, Caribbean and Gulf of Mexico for at least the next 7 to 10 days. In fact, we probably will not see another named storm this month and may have to wait until August before we see the next named storm (Debby).
None of the longer range model guidance, including the GFS model, the GFS ensemble model and the European ensemble model guidance forecasts any sort of tropical development through July 28th. I agree with this as there is large scale sinking air occurring across much of the Atlantic Basin and this will put a cap on any sort of tropical development from happening.
Period From Early-Mid August To Mid October Could Be Fairly Active In Terms Of Tropical Storm/Hurricane Threats For The Far Northeastern Caribbean, The Bahamas & Along The US East Coast From Eastern Florida Northward To Southern New England: I think the next time frame for increased tropical development chances across the Atlantic Basin will arrive by early August and intensify as we head into mid August. A new upward motion pulse of the Madden Julian Oscillation is expected to push into the Atlantic Basin during the first half of August leading to increased rainfall and storminess across the tropical Atlantic. This favorable background state across the Atlantic Basin will lead to a increased chance for tropical development as we get into early and mid August.
The very long range CFS model guidance continues to be very consistent in both showing tropical activity ramping up during August and also trending towards lower barometric pressures across the Atlantic Basin during the month of August. In fact, the CFS model continues to forecast a pretty active period for tropical storm/hurricane landfall threats from mid-August to mid-October in a couple of concentrated areas.
The first area that the CFS model is indicating that may be at risk from a tropical storm/hurricane threat is the region from the far northeastern Caribbean through the Bahamas and along the US East Coast from eastern Florida northward all the way to southern New England could be active with at least 3 tropical storm or hurricane threats between August 15 and October 15.
Second is that the central and eastern Caribbean may be quiet with no significant threats. This remains to be seen, but this idea seems plausible given the overall weather pattern.
Third is that the northwestern Caribbean into the Gulf of Mexico could become active tropically after September 15th.
Here Are My Thoughts: The overall trend towards things really ramping up in terms of tropical storm/hurricane formation from mid August to mid October is concerning. Analysis of the ocean water temperatures over the central and eastern Atlantic Basin between the Lesser Antilles and the coast of Africa (referred to as the Main Development Region) continue to warm up as the trade winds across the region are lighter than they were even a couple of weeks ago or so. There are strong signals in the model guidance that suggests the trade winds will remain light enough to allow for continuing warming of the ocean water temperatures to above average readings during August and September across the central and eastern Atlantic.
In addition to this, rainfall across the Sahel of Africa has been above average this year and this has led to the tropical waves pushing across the African continent being stronger than average this year. These tropical waves help to slow down the easterly trade winds and given that the tropical waves have been displaced a little further north this year, they are helping to warm up much of the Atlantic Main Development Region.
So, to me, it is concerning that the entire state of the Atlantic Basin may be shifting from one that was unfavorable for development (cool ocean water temperatures across the Main Development Region) to one that is currently becoming increasingly more favorable for development (near average and trending towards above average ocean water temperatures across the Main Development Region).
Now, to address the potential areas that could be at risk from any tropical storms or hurricanes. I think that there are two areas of concern:
The first is the area from the far northeastern Caribbean through the Bahamas and up the US East Coast from eastern Florida northward to southern New England. Systems this year have already been taking a path from the Bahamas northward to just offshore of the US East Coast (Chris was a great example of this). I suspect that we will see this continue with any tropical storms or hurricanes being guided from the far northeastern Caribbean through the Bahamas and then up the US East Coast. In fact, this was mentioned as a viable possibility in our 2018 Atlantic Hurricane Season forecast issued back in early April. Many times the atmosphere can send a signal to how things are going to progress over the next few weeks and I think we are seeing this signal now with both Chris and the path of the remnants of Beryl.
The second area of concern is the area from the northwestern Caribbean to the northeastern Gulf of Mexico. I think this area could be a concern as we get a later in the season (after September 15) and I could see a scenario of another tropical system taking a path much like Alberto did back in late May – except this time, the tropical system could be much stronger than what we had with Alberto.
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Area Of Disturbed Weather Halfway Between The Lesser Antilles & Africa (Between 35-40 West Longitude): An area of disturbed weather is being watched for signs of tropical development. This area of disturbed weather is located about halfway between the coast of Africa and the Lesser Antilles between 35-40 West Longitude.
Even though satellite imagery is showing quite a bit in the way of shower and thunderstorm activity, analysis reveals that there is no spin occurring at either the lower or mid-levels of the atmosphere. In addition, wind shear values are in the 10 to 20 knot range with ocean water temperatures in this area at around 27-28 Degrees Celsius. Analysis also indicates that this area of disturbed weather will encounter 25 knots of wind shear when it reaches about 45 West Longitude followed by much lower wind shear conditions west of 50 West Longitude.
The model guidance are in agreement with forecasting that a low pressure system may develop within this area of disturbed weather this weekend into early next week as it travels from 40 to 50 West Longitude before it begins to fall apart during the middle and late parts of next week while it approaches the Lesser Antilles due to the forecast of higher wind shear values. None of the model guidance are forecasting outright tropical development from this area of disturbed weather. With that said, I do think that this tropical disturbance and the couple of other tropical disturbances over western and central Africa need to be watched closely as they push westward.
Here Are My Thoughts: The tropical disturbance that is about halfway between the coast of Africa and the Lesser Antilles is actually in a somewhat favorable environment. It is far enough away from the colder ocean water temperatures and dry, dusty Saharan Air and is also being aided by the energy of the Inter-Tropical Convergence Zone. What is stopping this system from developing in the short term is the lack of a circulation. Model guidance seems to indicate that a low pressure system will form within this area of disturbed weather by Sunday and if this happens, then we are going to have to keep a close eye on it for signs of tropical development.
Another thing to consider is that if this area of disturbed weather gains any sort of latitude, it will encounter an unfavorable environment of cooler ocean water temperatures and Saharan Air. If development is going to occur, it will need to stay below 15 North Latitude.
All-in-all, tropical development is not expected with this tropical disturbance from today through at least Saturday. There is a chance, albeit a low one right now, that we could see some tropical development from it starting on Sunday and continuing into the first half of next week. For those of you in the Lesser Antilles, I would say just keep an eye on this disturbed weather for now as it is at least 6 days away from affecting the islands, if at all.
I'm also going to be keeping an eye on two other tropical disturbances that are currently located over western and central Africa. These two tropical disturbances may exit Africa at a rather high latitude which would limit development due to Saharan Air and cool ocean water temperatures. What these two other tropical disturbances may do is moisten up the atmosphere a bit and pave the way for other tropical disturbances to try and develop. All-in-all, however, the environmental conditions across the eastern Atlantic is more unfavorable than favorable for development, but all of the westward moving tropical waves will be monitored anyways, just in case.
The next tropical weather discussion will be issued on Saturday Morning or sooner if conditions warrant.
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Thanks for the update, Bob. I'm headed to SBH next week and hope for night time showers and sunny days!
 
Area Of Disturbed Weather Halfway Between The Lesser Antilles & Africa Has A Chance, Albeit A Low One, To Develop Tropically Next Week


Area Of Disturbed Weather Halfway Between The Lesser Antilles & Africa: I continue to keep an eye on an area of disturbed weather that is located about halfway between the coast of Africa and the Lesser Antilles, although this system is less organized than it was at this time yesterday. Satellite imagery indicates that there is little in the way of deep thunderstorm activity with just scattered showers and isolated thunderstorms noted. Latest analysis reveals that there may be two to three areas of circulation at the mid-levels of the atmosphere noted with this disturbed weather, but there is little low-level spin noted. This all means that this is a pretty disorganized disturbance and development, if any, will be very slow to occur.
The model guidance, as a whole, continues to indicate that at least a weak area of low pressure may develop within this area of disturbed weather towards the early part of next week. There are a few differences in the model guidance today as compared to yesterday. The first is that the latest guidance seems to indicate that this disturbed weather may make it further west before it completely falls apart than what was indicated yesterday. The second difference is that the latest guidance members hint at a further south track as compared to yesterday. The third difference is that the model guidance, the GFS and GFS ensemble model guidance in particular, point to more favorable upper level winds and more favorable environment through much of next week. This was something that wasn't really forecast by the guidance yesterday. With all of that said, none of the model guidance members, including the GFS, Canadian, European or UKMET models, forecasts any sort of tropical development across the central and eastern Tropical Atlantic for at least the next week.
Here Are My Thoughts: Even though this area of disturbed weather looks very disorganized this morning, I think that we still need to keep an eye on it for signs of increased organization over the next couple of days or so. The trends in the model guidance towards a more favorable are something to be watched, although, if this disturbed weather does stay disorganized, it wont be able to take advantage of a more favorable environment. This trend in the model guidance is supported by the current wind shear map which shows 15 knots or less of shear across much of the central and eastern Tropical Atlantic as far west as the Lesser Antilles.
All-in-all, tropical development is not expected with this tropical disturbance for at least the next couple of days, if not longer. If no organization occurs with this system and it remains a disorganized mess, then there would be no chance for it to develop into a tropical system.
For those of you in the Lesser Antilles, I would say just keep an eye on this disorganized area of disturbed weather for now. The earliest it may impact you is around Thursday. One thing to note is that even if this system does not develop, it still has the chance to bring parts of the Lesser Antilles some gusty winds and locally heavy rainfall around Thursday of next week.
Elsewhere Across The Atlantic, Caribbean & Gulf Of Mexico: It appears that we may see another round of tropical development over the far North Atlantic sometime next week as an area of low pressure now located well to the east-southeast of Cape Cod, Massachusetts will push further offshore over the next few days. Some of the model guidance, the Canadian model in particular, forecasts that this low pressure system may try to transform into a tropical storm when it's located way out near 40 North Latitude, 50 West Longitude around Tuesday and Wednesday of next week. Even if we do see tropical development from it, it will pose no threat to any land masses and it would likely be another short lived tropical system.
A flareup of shower and thunderstorm activity is occurring on the northern end of a tropical wave that is currently pushing through the Lesser Antilles. Even if this area of convection breaks off from the main tropical wave, the environmental conditions are not favorable for development and the current flareup that we are seeing is being caused by the divergent flow aloft on the eastern side of a upper level trough of low pressure. All-in-all, tropical development is not expected with this flareup of thunderstorm activity.
Looking further out, there could be two additional tropical disturbances to keep an eye on starting about 10 days from now. These two disturbances are forecast by a majority of the model guidance to push off of the coast of Africa and move westward across the eastern and central Tropical Atlantic. The GFS model and the GFS ensemble model forecasts that the first disturbance may make it as far west as the Lesser Antilles by August 27. In fact, the CFS model, which also sees this potential forecasts this first disturbance to develop into a tropical cyclone very close to the US East Coast during Labor Day weekend (September 1-3) with the second disturbance staying well offshore and remaining over the open Atlantic.
Given that most of the model guidance are “seeing” this particular setup of an individual tropical disturbance moving off of Africa in 10 days from now (around August 20), I think it is definitely something that may require close monitoring once we near this time frame. As we all know, the model guidance forecast of where an individual system will change with each new forecast run and this is something that we shouldn't look at very closely. What I am looking at closely is the pattern of the tropics slowly waking up and the very real possibility of a weather pattern that features westward moving tropical disturbances that struggle to organize until they are west of 60 West Longitude and end up being a threat to the US East Coast starting as soon as the August 20 to September 1 time frame.
The next tropical weather discussion will be issued on Monday Morning o
 
August 15, 2018

Sub-Tropical Depression #5 Forms Over The Far North Atlantic & Is No Threat To Any Land Masses; Area Of Shower & Thunderstorm Activity About Halfway Between The Lesser Antilles & The Coast Of Africa Is Being Monitored; Uptick In Tropical Development Looking Increasingly More Possible Towards The End Of This Month


Sub-Tropical Depression #5:
5 am EDT/4 am CDT Statistics:
Location: 37.6 North Latitude, 45.6 West Longitude or about 1015 miles to the west of the Azores.
Maximum Winds: 35 mph.
Minimum Central Pressure: 1009 Millibars or 29.80 Inches.
Forward Movement: North at a forward speed of 5 mph.
The low pressure system that has tracked out into the far North Atlantic about 1000 miles to the west of the Azores Islands has developed enough of a structure to be considered a sub-tropical depression. Some strengthening of this system is possible over the next day or two as it traverses across ocean water temperatures of around 80 Degrees Fahrenheit and a low wind shear environment. This means that it looks quite plausible that the depression will become Tropical Storm Ernesto within the next 24 hours or so. After about Saturday, much cooler ocean water temperatures and a marked increase in wind shear will lead to this system weakening and merging with a frontal boundary.
Bottom line is that Sub-Tropical Depression #5 poses no threat to any land masses.
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Model Track Forecast For Sub-Tropical Depression #5:
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Model Intensity Forecast For Sub-Tropical Depression #5:
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Satellite Imagery Of Sub-Tropical Depression #5:
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Area Of Shower & Thunderstorm Activity Over The Central Tropical Atlantic Halfway Between The Lesser Antilles & The Coast Of Africa Is Being Monitored: Satellite imagery indicates that there is an area of shower and thunderstorm activity in the vicinity of 7 North Latitude and 43 West Longitude. This activity is connected to the Inter-Tropical Convergence Zone. Given that this area of shower and thunderstorm activity is within a low wind shear environment and there may be some spin to the cloud structure, it is a system that I will be keeping a close eye on.
Right now, none of the model guidance forecasts development from this system. This is likely due to the fact that it will be encountering very strong wind shear by the time it reaches the central and southern Lesser Antilles on Saturday night and Sunday.
I think that, given the favorable environmental conditions, there is the possibility for some brief tropical development over the next 2 to 3 days. Any development, however, should be short lived as the unfavorable environment near the Lesser Antilles is likely to lead to degeneration and dissipation later this weekend.
Even though this system is expected to be in a much weakened state by the time it reaches the Lesser Antilles, I urge everyone across the islands to monitor this system closely, in case conditions are more favorable than what is being forecast right now. Remember back in July with Beryl when the storm held together much longer than what was originally forecast.
Bottom line is that this area of showers and thunderstorms certainly has my attention and I will be monitoring it closely.
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An Uptick In Tropical Development Is Looking Increasingly More Possible Towards The End Of This Month: It appears that the longer range model guidance is now beginning to show the Tropical Atlantic waking up with development chances increasing by the end of this month. The GFS model guidance shows lowering barometric pressures across the eastern Atlantic by the end of next week with two very robust areas of disturbed weather pushing westward during the week of August 27. In fact, last night's GFS model showed both of these systems becoming tropical cyclones with one of them impacting the Lesser Antilles around August 30.
The forecast of lowering barometric pressures materializing over the eastern Atlantic is supported by not only the Canadian and European operational models, but also the GFS ensemble and European ensemble guidance.
This is the first time that I have seen the GFS model start to forecast a tropical cyclone to develop in the tropical Atlantic since Beryl back in early July. I think that this is a signal that a pattern change towards a more active period in tropical development is about to happen. This has the support of the background atmosphere state in which the Madden Julian Oscillation will turn favorable for tropical development around late August.
There are some parallels between this Hurricane Season and the 2002 Hurricane Season. If this holds true, then we could very well see a 4 to 5 week burst of activity from late August to early October. It should be noted that in 2002, there were 9 named storms with 5 of those storms becoming hurricanes between August 29 and October 4. In addition, there were 6 tropical cyclones that made landfall on the US coastline during that roughly 5 week period.
So, while it is very quiet right now, there is increasing evidence in the data that suggest we will see a marked increase in tropical activity by the end of this month that lasts through September and into early October.
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The next tropical weather discussion will be issued on Thursday Morning or sooner if conditions warrant.



If you have questions regarding this discussion, do not hesitate to contact me at rlightbown@crownweather.com.

Disclaimer: All forecasts herein are made to the best ability of the forecaster. However, due to standard forecasting error, these forecasts cannot be guaranteed. Any action or inaction taken by users of this forecast is the sole responsibility of that user.








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Invest 99-L Located To The East Of The Windward Islands Continues To Be Monitored Closely For Possible Development; Uptick In Tropical Development Continues To Look Quite Possible Towards The End Of This Month


Invest 99-L Located About 750 Miles To The East-Southeast Of The Windward Islands: We continue to keep an eye on Invest 99-L, which is a tropical wave that is located about 750 miles to the east-southeast of the Windward Islands. Satellite imagery indicates that the associated shower and thunderstorm activity is more disorganized this morning as compared to what it looked like for much of yesterday. Latest analysis indicates that this system remains within a favorable wind shear environment, however, the overall structure of it is fairly disorganized. Given that Invest 99-L is positioned far enough south so that any dry air wont impact it and that it is within a low wind shear environment, I think that we should see at least some slow development from it over the next couple of days or so as it moves westward towards the Windward Islands.
It seems that the various model guidance members are playing “catch-up” with trying to see Invest 99-L. For instance, the GFS model both doesn't “see” Invest 99-L and also doesn't develop it. The European model, on the other hand, briefly develops Invest 99-L into a tropical depression and even a tropical storm near Barbados on Saturday morning before falling apart in the eastern Caribbean by Sunday night into Monday. I am “throwing out” the track intensity guidance as it looks far too strong with its rapid intensification of Invest 99-L, especially given the increasingly more unfavorable environment in the eastern Caribbean.
Here Are My Thoughts: Even though Invest 99-L is disorganized, I think that the environmental conditions are favorable enough for it to develop briefly into either a tropical depression or perhaps even a tropical storm before it reaches Barbados and the Windward Islands on Saturday. Beyond that, it seems most possible, right now, that Invest 99-L will weaken and dissipate in the eastern and central Caribbean late this weekend and early next week due to increasingly more unfavorable environmental conditions.
Everyone across Barbados and across the Windward Islands and parts of the Leeward Islands should closely monitor the progress of Invest 99-L. At the minimum, this system will bring you locally heavy rainfall and gusty winds beginning as soon as this afternoon and continuing through Friday and Saturday.
Bottom line is that I am monitoring Invest 99-L very closely and will continue to have updates for you as conditions warrant.
Invest 99-L Information:
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Model Track Forecast:
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Satellite Imagery:
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Area Of Disturbed Weather Located To The South-Southeast Of Bermuda: I wanted to briefly touch on an area of disturbed weather that is located to the south-southeast of Bermuda. These showers and thunderstorms are located at the tail end of a trough of low pressure connected to Sub-Tropical Storm Ernesto. This convection has persisted, in some form, since Tuesday evening and has been moving on a generally westward track since yesterday afternoon.
Analysis of the environmental conditions shows that wind shear on the order of up to 25 knots is impacting this system. In addition, it is now beginning to encounter some very dry air located to its west.
All-in-all, I do not anticipate any sort of tropical development from this area of disturbed weather. With that said, it is an item that I am going to keep an eye on anyways, just in case.

An Uptick In Tropical Development Continues To Look Quite Possible Towards The End Of This Month: The longer range model guidance are really beginning to show the Tropical Atlantic waking up by the end of this month. The GFS model guidance is starting to become persistent in showing a marked increase in convective activity across the eastern Tropical Atlantic as soon as late next week with the model showing at least a couple of systems of concern moving westward during the week of August 27.
Going even further out in time, the latest CFS model guidance is hinting that the western Atlantic could be a pretty busy area in terms of tropical systems during the first half of September. The CFS model is forecasting at least 3 tropical cyclones that could be of concern for the southeastern United States and the US Gulf Coast during the first half of September.
As I mentioned yesterday, even though we do have Sub-Tropical Storm Ernesto over the far North Atlantic and Invest 99-L to the east of the Windward Islands, there is strong evidence in the data that suggests we are about to turn the switch on in terms of tropical development across the Atlantic Basin. I do still think that will see a marked increase in tropical activity by the end of this month that lasts through September and into early October.
The next tropical weather discussion will be issued on Friday Morning or sooner if conditions warrant.
 
Invest 99-L Plus Other Items Now & In The Near Future That Require Monitoring


Invest 99-L Located About 500 Miles To The East-Southeast Of The Windward Islands:Invest 99-L, which is a tropical wave located about 500 miles or so to the east-southeast of the Windward Islands, continues to be monitored closely. Satellite imagery over the past 48 hours has shown that the shower and thunderstorm activity associated with Invest 99-L has been going through cycles of flaring up for up to 12 hours followed by the convection dying out for up to 12 hours. Currently, we are in a cycle where the convection is just beginning to flare back up. This type of convective process does not usually lead to tropical development as normally you would want to see the convection persist for a day or two before you really start looking at the tropical development chances.
Even though, the wind shear values are favorable for development, the lack of sustained, robust thunderstorm activity makes me think that development is unlikely and this is supported by all of the reliable model guidance. Very strong wind shear across much of the Caribbean is likely to lead to Invest 99-L eventually dissipating.
Everyone across Barbados and across the Windward Islands and parts of the Leeward Islands should still be ready for locally heavy rainfall and gusty winds today through this weekend.
Invest 99-L Information:
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Model Track Forecast:
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Satellite Imagery:
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Other Items To Watch Besides Invest 99-L: I am also still watching an area of disturbed weather that is located to the east of the Bahamas. This disturbed weather formed at the tail end of Tropical Storm Ernesto and now seems to breaking off and pushing slowly westward. Much like Invest 99-L, there has been a lack of deep, persistent convection associated with this area of disturbed weather and most of the convection has gone through a cycle of flaring up and then dying down.
Analysis of the environmental conditions shows that wind shear values are now favorable for development, however, there is dry air present on the northern and northwestern side of this disturbance. As I mentioned yesterday, I am not expecting tropical development from it, however, it is an item that I am going to keep an eye on anyways, just in case.
The longer range model guidance continues to show the Tropical Atlantic trying to wake up by the end of this month. The GFS model guidance continues to forecast a increase in overall convection across the Atlantic Basin starting as soon as late next week with the model showing at least a couple of systems of concern moving westward during the week of August 27.
Going even further out in time, the latest CFS model guidance is hinting that the western Atlantic could be a pretty busy area in terms of tropical systems during the first half of September. The CFS model continues to forecast at least 3 tropical cyclones that could be of concern for the US East Coast and parts of the US Gulf Coast during the first half of September.
As I have mentioned all week, even though we do have Sub-Tropical Storm Ernesto over the far North Atlantic and Invest 99-L to the east of the Windward Islands, there is strong evidence in the data that suggests we are about to turn the switch on in terms of tropical development across the Atlantic Basin. I do still think that will see a marked increase in tropical activity by the end of this month that lasts through September and into early October.
 
Tropical Development From African Tropical Waves & Tropical Development In-Close To The United States Are Two Items We Will Be Monitoring Very Closely Over The Next Month


Tropical Development From African Tropical Waves Will Need To Be Watched Over The Next Month: A tropical wave now crossing the western coast of Africa is an item that I'm going to keep an eye on, however, conditions across much of the eastern and central Atlantic are unfavorable for development due to an abundance of sinking air. The reason why I think it is a good idea to keep an eye on this tropical wave is because it could be in the vicinity of the US Southeast Coast in about 10 days to two weeks from now where conditions may be more favorable for development.
The model guidance, including the GFS, Canadian and European models, all indicate that the energy and moisture from this tropical wave will be very near the eastern Bahamas by August 28 and then near the US Southeast Coast by around September 2 or 3. We will then have to keep an eye on the very real potential for tropical development in-close to the US Southeast Coast. I will cover this potential a lot more in the next section of this discussion.
The reason why tropical waves pushing off of the coast of Africa are falling apart quickly is because the atmospheric state across the central and eastern Atlantic isn't favorable. The combination of dry, dusty air and higher than average barometric pressures are leading to a unfavorable state in the atmosphere for tropical development.
With that said, the barometric pressures across the African continent are beginning to fall. This says to me that we should start to see a uptick in tropical disturbance activity pushing off of the coast of Africa within the next week to ten days or so. The latest long range model guidance are now beginning to see this potential with last night's GFS model forecasting a full-fledged tropical cyclone in the eastern Tropical Atlantic at the very beginning of September and the European EPS model showing tropical development in the eastern Atlantic at the end of this month and the beginning of next month.
While this hurricane season has been the complete opposite of last hurricane season, which is great news so far, I am NOT about to pull the plug on this season as I do think we will see a fairly busy September in terms of tropical cyclones with this possibly continuing into part of October.

Tropical Development In-Close To The United States Coastline Is A Concern From Now Through September: The overall weather pattern across North America is expected to feature another bout of near record heat across the Northeastern and Midwestern United States from about August 27 through September 2 as a large upper level ridge of high pressure flexes its muscle. This type of weather pattern is concerning as oftentimes you will see an opposite response of lowering barometric pressures to the south of the high pressure ridge.
This means that we could see an area that could be favorable for tropical development very near the US Southeast Coast beginning during the period of August 27 to September 2. In addition, the orientation of the upper level high pressure ridge is such that it would prevent any incoming tropical systems from curving away from the United States.
I think that we are going to have to really watch out for tropical development in-close to the US coastline starting this coming week and then especially as we get into next week and beyond.
This type of tropical development could occur in a few different ways -
The first way is from an African tropical wave that waited to develop until it reached the western Atlantic. That tropical wave that is now pushing off of the coast of Africa is one such candidate as a large majority of the long range model forecasts that this tropical wave will be in the vicinity of the US Southeast coast around September 2-3. Right now, none of the operational model guidance members forecasts tropical development, but the long range European EPS ensemble model does have a few members strongly hinting at tropical development.
The second way that we could see tropical development in-close to the US coastline is with either a disturbance forming along a frontal boundary and then being “left behind” to fester and develop near the US Southeast coast or in the northern Gulf of Mexico or a large thunderstorm complex to move off of the coast and develop in the warm waters near the US Southeast coast or in the northern Gulf of Mexico.
Furthermore, there are teleconnections between what the weather is like right now over the far western Pacific to what the weather could be in about 2 weeks from now. These teleconnections are currently pointing to potential tropical development very near the coast of the southeastern United States. This same method was used with success when forecasting the development of Hurricane Chris back in early July and it will be “interesting” to see if this method of forecasting 2 to 3 weeks in advance is successful again.
Bottom Line Is That the tropical waves that each new tropical wave pushing off of the coast of Africa will saturate the atmosphere and eventually we will see an overall atmosphere over the Tropical Atlantic that is at least somewhat favorable for tropical development. Even more important, however, is that I think we need to pay particularly close attention to in-close tropical development along the US Southeast Coast and also over the northern Gulf of Mexico over at least the next 3 to 4 weeks. Unlike the long tracking tropical waves from Africa, these sneaky in-close systems sometimes gives us a short amount of time to prepare and thus is why it is something to keep close tabs on.
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Two Areas To Watch For Potential Tropical Development – (1) Bahamas This Weekend Into The Gulf Of Mexico Next Week; (2) Eastern Tropical Atlantic By This Weekend


Slight Chance For Tropical Development From The Bahamas This Weekend Into The Gulf Of Mexico Next Week: We are keeping an eye on a tropical wave that is currently located over the central Atlantic near 60 West Longitude. Even though this tropical wave lacks any sort of deep or sustained convection, it is a system that should be monitored closely once it moves into the Bahamas at the end of this week and into the Gulf of Mexico this weekend.
The operational model guidance, as a whole, have backed off some on forecasting development of this tropical wave in the Gulf of Mexico. The only operational model right now that even hints at development is the European model which shows a weak low pressure system forming over the western Gulf of Mexico near the lower Texas coast next Tuesday. It seems the model guidance are much more interested in the potential tropical development over the eastern Atlantic as we get into this weekend and next week.
It seems the ensemble model guidance are a little more interested in forecasting development of this tropical wave in the Gulf of Mexico. The GFS ensemble guidance shows a few members forecasting development in the northern Bahamas early next week that pushes westward into the Gulf of Mexico towards the middle part of next week. The European ensemble guidance has a couple of members that show development in the eastern Gulf of Mexico early next week.
Here Are My Thoughts: Even though the model guidance, as a whole, have backed off on forecasting development of this tropical wave from the Bahamas into the Gulf of Mexico, it is still an item that I want to keep a close eye on. The big reason why it is such a concern is because of the very warm ocean water temperatures that are present in this area.
The reason for the lack of development from the model guidance seems to be the overall forecast for strong enough wind shear to prevent any sort of tropical development until perhaps at the last minute as this system nears the lower Texas coast next Tuesday.
At this point, I do not expect any sort of tropical development from this tropical wave anytime soon due to a lack of sustained deep convection within an environment that is very unfavorable for development due to strong wind shear. Even though the model guidance shows no development from this wave, I do think that we will want to keep an eye on it once it reaches the area of the Bahamas this weekend and the Gulf of Mexico next week. If the guidance is correct and we do see strong wind shear, then development probably will not occur. On the other hand, if the guidance is overforecasting the amount of wind shear, then we could very well see some sort of tropical development either this weekend in the Bahamas or next week as this system moves westward across the Gulf of Mexico.

Eastern Tropical Atlantic Tropical Development Is A Strong Possibility By This Weekend: The eastern and central tropical Atlantic is likely to be a spot to watch for tropical development by or before this weekend. Satellite imagery shows 2 strong tropical waves that bear very close scrutiny for development chances. The first tropical wave is over the easternmost Atlantic just off of the coast of Africa. Moisture and convection with this tropical wave has increased and it appears that the thunderstorm activity associated with it is holding together and this is something that will need to be watched closely.
The second tropical wave that we need to watch very closely is now located over central Africa and this wave is exhibiting moderate to strong thunderstorm activity. The second wave is expected to push off of the coast of Africa either on Wednesday or Thursday.
There is strong model guidance agreement that we will see tropical development from either one or both of these tropical waves by or before this weekend over the eastern tropical Atlantic.
The GFS model forecasts that the first tropical wave will develop by this weekend, but then forecasts it to turn northward well east of the Lesser Antilles by late next week. The GFS model also forecasts 2 additional tropical cyclones to form over the eastern Atlantic next week.
The European model forecasts no development from the first tropical wave but does forecast tropical development from the second tropical wave over the eastern Atlantic late this weekend. By the middle part of next week, the European model forecasts that there could be 2 tropical cyclones in the central and eastern Atlantic, one near 50 West Longitude and the other near the Cape Verde Islands.
Here Are My Thoughts: I think that there is about a 50-50 chance that we will see tropical development from at least one of the tropical waves moving off of Africa by this weekend. In fact, there is the very real possibility that we may have 2 tropical cyclones over the central and eastern tropical Atlantic by the middle and later parts of next week.
The environmental conditions across the central and eastern Atlantic are gradually becoming more favorable for development. Wind shear values are 15 knots or less along and south of 15 North Latitude for areas east of 50 West Longitude. In addition, the entire background state of the atmosphere is gradually becoming more favorable for tropical development across the Atlantic Basin after being in a unfavorable state for the last month or so.
This means that tropical activity across the Atlantic Basin will be on the upswing this week with a 50-50 chance for development by this weekend. In addition, September looks like it could be an active month in terms of potential tropical activity across the Atlantic Basin. Obviously, it is too soon to tell where each system may track, so everyone needs to keep close tabs on the tropics.
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The next tropical weather discussion will be issued on Wednesday Morning or sooner if conditions warrant.
 
Tropical Development From The Bahamas Into The Gulf Of Mexico Is Possible Between Monday & Thursday Of Next Week; Tropical Development Over The Eastern Tropical Atlantic Is Also Possible By This Weekend; Additional Tropical Development Over The Eastern Tropical Development Is Possible By Late Next Week


Tropical Development From The Bahamas Into The Gulf Of Mexico Is Possible Between Monday & Thursday Of Next Week: A tropical wave is currently located over the Lesser Antilles. Satellite imagery this morning indicates that there has been some increase in shower and thunderstorm activity with this tropical wave, however, immediate tropical development is extremely unlikely. The reason why immediate tropical development is not expected is due to strong wind shear on the order of 30 to 40 knots impacting it.
This tropical wave, however, will need to be watched closely once it moves into the Bahamas late this weekend and then into the Gulf of Mexico during the first half of next week. Environmental conditions may be more favorable in these areas and tropical development continues to be possible anytime between Monday and Wednesday of next week.
Looking at the latest model guidance – It appears that the European model is really the only model that forecasts outright development of this tropical wave. All of the other operational model guidance members, including the GFS, Canadian and UKMET models forecasts little or no tropical development of this system.
It is quite possible that the European model could be wrong with its forecast of tropical development – It has happened before where this model has over strengthened a system that never materialized.
The ensemble guidance, on the other hand, seems more interested in forecasting tropical development in the Gulf of Mexico. The GFS ensemble guidance shows a few members forecasting development over the northern Gulf of Mexico around the middle part of next week with the GFS ensemble guidance also forecasting a 20-30 percent chance for tropical development in the northern Gulf of Mexico during the first half of next week.
The European ensemble tropical cyclone probability guidance is forecasting a 45-50 percent chance for tropical development in the northwestern Bahamas on Sunday and Monday followed by a 50 percent chance for tropical development in the northern Gulf of Mexico by about Wednesday of next week. In addition, the European ensemble guidance is forecasting a 25 percent chance that this system will be a tropical storm by the time it reaches the northern Gulf of Mexico at the middle part of next week.
The reason for the difference between the GFS and European model is its forecast upper air pattern. The European model seems to show a favorable weather pattern for tropical development while the GFS model forecasts a unfavorable weather pattern consisting of a trough of low pressure just off of the US Southeast Coast. It should be noted that the GFS model does have a bias of digging troughs of low pressure too far south and if this is the case with this system, then the GFS model may be vastly under forecasting development of this tropical wave.
Here Are My Thoughts: First of all, I do not expect any sort of tropical development from this tropical wave throughout the rest of this week due to unfavorable environmental conditions (strong wind shear). This tropical wave is expected to reach the northern and western Bahamas this weekend where the environmental conditions may become more favorable for development. A look at current wind shear values show that there is still upwards of 20-25 knots of wind shear occurring over the Bahamas and if this area of stronger wind shear persists in this area, then development probably would wait until this system reaches the Gulf of Mexico where wind shear values of 20 knots or less are widespread.
My thinking right now is that there is a 10-20 percent chance for tropical development late this weekend into early next week in the northern and western Bahamas.
In addition, I'm going with a 30 percent chance for tropical development in the northern Gulf of Mexico from Tuesday to Thursday of next week.
At this point, the possibility for tropical development in either the Bahamas or the northern Gulf of Mexico is something to just keep an eye on for now. It is still way too soon to start “ringing any alarm bells” over this system.

Eastern Tropical Atlantic Tropical Development Continues To Be A Strong Possibility By This Weekend With Additional Development Very Possible By Late Next Week: The eastern tropical Atlantic is going to be a spot to really watch for tropical development starting this weekend and continuing for at least the next 10 to 15 days and probably longer.
The first system we are watching closely is a strong tropical wave now located over western Africa. This system is expected to push off of the coast of Africa into the far eastern Atlantic by Thursday night or Friday. The environmental conditions over the eastern Atlantic are favorable for development and we could see a tropical depression or a tropical storm form near the Cabo Verde Islands sometime this weekend.
The good news is that even though most of the model guidance forecasts significant intensification of this tropical system, they all agree with forecasting it to turn to the north and out into the open Atlantic somewhere between 40 and 50 West Longitude by the middle part of next week. Given the northerly latitude this tropical wave will be pushing off of Africa at, I think a curve safely into the open Atlantic seems most likely right now.
I think the system to watch in terms of a much more westward track is a tropical wave that is forecast to push off of the coast of Africa around Tuesday or Wednesday of next week. This second tropical wave may wait to develop and thus be able to push fairly far to the west in longitude. A third tropical wave is forecast, mainly by the European model, to push off of the coast of Africa around September 7 or 8 and if this does happen, then it would also be a system that would need to be watched closely as it may push fairly far to the west in longitude.
Bottom Line Is That I think that we could see anywhere between 2 and 4 tropical storms form in just the next 10 to 14 days across the Atlantic Basin. So, get ready, it's about to get quite busy in terms of tropical storm/hurricane tracking across the Atlantic.
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