2020 Hurricane Season

[Paul Tallet]

TROPICAL STORM LAURA ... WHERE IS MARCO?

Now we have some irony.

The NHC is backing off development of Laura (formerly TD 14). This is the one that I believed was designated Tropical Depression status, let alone Tropical Storm status, rather prematurely. It is still very ragged although it will produce heavy rains wherever it goes ... a point to which I will come later.

TD 13 is still TD 13 despite higher clarity with regard to it's centre and, having got a handle on the centre, there is more confidence in it's future track which has been shifted more to the east, meaning that there will be less interaction with the Yucatan Peninsula ... what does that mean? Correct ... more potential for strengthening. So TD 13 probably has more right to be named a Tropical Storm than Laura ... in fact it should be Laura and not Marco!!

But, while our future Marco is the current favourite to attain hurricane status in the Gulf there are strong wind shearing elements ahead as the storm bears down on (likely) Texas and, hopefully, Marco will be a weaker storm when it makes landfall late Tuesday.


Meanwhile, back to the Northern Antilles and Laura, the very vague track is taking a westerly trend taking the disturbance over the Greater Antilles and this land interaction will weaken the system, although the NHC are still predicting a hurricane in the Gulf with landfall trending west towards Louisiana and Mississippi, again this is close to a convergence with Marco.

The 2 most reputable models (GFS and the EURO) do not see Laura developing into a hurricane. This is significant, however these storms can crank up very quickly and a major hurricane (or 2) in the Gulf cannot be ruled out at this stage.

Updates to follow ...

Regards

[Hugh S]

Interesting article about the current storms and predictions for the season.

The pandemic is a complicating factor. Some scientists say that reduced air traffic is affecting forecasts, as fewer planes are now collating weather information. “I do think this year’s reduced weather data from commercial aircraft has made a big difference,” said Lightbown.

https://www.theguardian.com/world/2020/ ... oronavirus

Thanks for the updates, Paul.

[Paul Tallet]

MARCO & LAURA ... A LEARNING EXPERIENCE

This is quite fascinating ... we have 2 very unpredictable storms that could enter the Gulf of Mexico simultaneously but there are decreasing reservations regarding the outcomes.

Marco may miss the Yucatan Peninsula which promotes strengthening but as I said in the last post, troubles lie ahead in terms of wind shear. To see a demonstration of this just look at the sat loops and see the outflow to the north east of the storm towards Florida which is getting heavy rains from Marco.

The Models are trending west for Marco's landfall but a minority of the models suggest that Marco could be guided by the north easterly wind shear and take it over Florida or Alabama ... I get that and would not rule it out.

Just as I write, Marco has just been upgraded to hurricane status and is no longer expected to have any land interaction before it's predicted arrival in Texas / Louisiana by Tuesday morning.

It goes to show how diverse the model spread is and how difficult it is to make predictions about these storms.

Laura ... in my opinion, is still ragged but there has been an enormous increase in thunderstorm activity that indicates that the various vorticity cells are gelling together ... again there are challenges ahead for this storm because it may be impacted by land interaction over Hispaniola and Cuba. Strengthening is likely to be reduced by this factor but if the Storm can keep just north of the current forecasted track, even by a few miles, we have a different outcome altogether and a potential major hurricane.

It's a fine line and we have to remember that Marco and Laura offer heavy rainfall events wherever they go and at whatever strength they are. Hurricane status just adds wind and storm surge risks.

Convergence factors ... there is no way Marco and Laura will converge or join. If they stay far enough apart there is the potential of double impacts on the south US coasts Teusday/Wednesday but one storm is likely to give way to the other OR the converse wind fields would 'ping off' the weaker storm pushing Laura north or south depending on the strength of Marco.

This is pure speculation on my part and it is still early days despite the fact that impacts of these storms will occur in the US within 72 hours.

As a consequence ... updates have to follow ...

Regards

[Paul Tallet]

Hello Hugh.

That is indeed an interesting article.

While flight operations are a valuable source of information we are increasingly reliant on satellite coverage and it is possible to make vague judgements on the development and strength of Storms in the tropics, far better than 10 years ago. Buoys are also becoming more widespread around the oceans, primarily to warn of Tsunamis, but they can record conditions, pressure gradients and sea heights within passing hurricanes.

There is also always more than one factor that creates an above active hurricane season in the Atlantic. I hope I have got this the right way round but La Nina in the Pacific has an influence as well as ocean heat. So, currently the Pacific Ocean is rather cold where the Atlantic is cooking and there are other factors such as periodic oscillation around the ITCZ which, if it's timing coincides with the hurricane season, can enhance storm development.

On the subject of Global warming, many may disagree with me, but I believe that the powers of mother nature are far greater than the abuse our weak specie has imposed on our world and our ability to correct it. Her abilities to reverse damage are inexplicably more powerful in order to balance the audit sheet, so to speak.

Our world has gone through many warming and cooling cycles long before our specie became the dominant force it is today, some of these have been extinction events such as a super volcano eruption, or possibly a pandemic. Volcanos, in addition to hurricanes, act as temperature control systems for the planet, but not necessarily for humans or any other specie that happens to exist at the time ... we are incidental and unlikely to be a major factor in the unimaginable timeline and condition of the life of Earth which I believe is self-healing.

I believe that we should focus more on the pollutions that are of immediate importance (to us), protect what we can and allow mother nature to balance the wider aspects of our world in her own sweet, but potentially devastating, way ... it is a matter of when.

Oh wouldn't you love to have a chinwag about all these issues over a (plastic!!) glass of Port or a Carib, standing neck deep in the blessed waters of Castara and social distancing with a face mask on

Regards

[Hugh S]

We will get together in those turquoise waters for that lime and I hope the masks will be snorkeling masks. Those other masks would only interfere with the beer.

[Paul Tallet]

MARCO & LAURA ... A FEAST OF COMPLICATION

If we are to take a snapshot of the model guidance with regard to these 2 storms and assume that nothing changes then Louisiana is going to experience 2 hurricane landfalls within 48 hours with the first striking late Monday and the second striking late Wednesday.

As I suggested, the future track of Marco has been nudging steadily towards the east and Laura is likely to be steered westwards by a ridge of high pressure to the north.

But changes are happening by the hour and forecasting these 2 storms is highly complicated with Laura's potential interaction with land and Marco battling wind shear during it's northward path through the Gulf.

So we have both track and strength uncertainties. For a short time last night, Marco was designated hurricane status but this appears to have been a mistake or system error and just goes to show how complex the situation is in the Gulf.

Those that live in the Gulf States must prepare for the worst and to not assume that it will be just Louisiana. Even if these storms weaken they present widespread rain hazards and there is a chance that one or both of these storms could rapidly develop into major hurricanes.

I will update later today.

Regards

[Paul Tallet]

HURRICANE MARCO ... TS LAURA

Marco's future is pretty well wrapped up as the hurricane bears down on Louisiana with landfall expected within 24 hours, however there is still some uncertainty about the precise track although as time passes the spread of uncertainty will narrow. Marco's track has been edging to the east and it is worth noting that the heaviest rains are on the east side so Alabama should take impacts from this rainfall.

Marco is a small hurricane so the damaging hurricane force winds will affect a limited area of up to 150 miles across plus Marco will weaken very quickly. But the rains will be a problem over a much wider area and will last much longer. There is a small chance of significant intensification so all the Gulf States should be prepared.


Laura ... this is a much larger storm with a wind field of at least 300 miles across. If the storm intensifies in the Gulf then the wind is likely to expand and there could be a large swath of hurricane force winds, impacting much wider areas.

Although news is hard to come by while countries are being battered by these storms there are estimated rainfall expectations in excess of 12 inches along the Greater Antilles and 3 to 4 inches as far and wide as Jamaica and the Bahamas. One of the countries in Laura's path is Haiti and this poor country has had no end of disasters in recent years with several hurricanes and even a major earthquake. Haiti, for now, is the area of greatest need in terms of relief / support.

Laura has yet to travel along the length of Cuba and intensification is inevitable once the storm emerges into the Gulf. It is a matter of how much time Laura's centre is over dry land and, still, no one has been able to pin down the elusive centre for sure and therefore, the future track is questionable even though there are suggestions it will be Louisiana again ... it is edging west and that would affect Texas however, as I said earlier, Laura is a much bigger storm and will impact wider areas.

Laura's story has yet to be told. But we must keep our thoughts with Haiti where the casualties and impacts are likely to be more profound.

Regards

[Paul Tallet]

HURRICANE LAURA ... HEADING FOR ....

Well, after the last few days I would not take anything too seriously when accounting for the advancements in weather model technology. Even this seems perplexed when giving predictions on strength, track, speed and even finding the centre of these storms. But these systems are far better than they were 10 years ago.

So ... Marco was expected to be a weak hurricane at landfall in Louisiana and I thought it was all wrapped up. So, against all expectations, Marco decided to give up, slowed down, weakened and almost completely dissipated before a half hearted landfall in west Louisiana. Marco is now dead.

Good news for Louisiana, but Hurricane Laura brings potentially graver consequences as a storm of greater proportions, both in size and malicious intent. So I hope those that braced themselves for the overstated arrival of Marco do not take Laura lightly.

Laura achieved the NHC award of hurricane status several hours ago as it left the western tip of Cuba. However it does not seem apparent that Laura's centre spent all of it's time over Cuba's landmass and, as a consequence, a 'not too bad looking' Laura emerged into the Gulf to engorge itself on the cooking waters and the welcoming environment ... just short of a few cushions.

The track, I stress currently, is set for the border between Texas and Louisiana but this is a larger storm and impacts are likely up to 200 miles either side of Laura's centre, even potentially wider if we take account of uncertainties in the model consensus.

The strength is speculative but there is little reason to believe that Laura will be anything other than a major hurricane at landfall with potentially catastrophic winds. It is a matter of how far the hurricane force wind field will extend from the centre and this can vary between the 4 quadrants around the storm.

Above all and regardless of the storm's wind strength are the rainfall impacts that will be widespread and the storm surge that will be limited to coastal areas.

Weather conditions will begin deteriorating by midday Wednesday followed by about 24 hours of hurricane conditions. These conditions will vary over relatively short distances, some will get it worse than others.

If there are any changes I will post an update.

Regards

[Paul Tallet]

GRAVE CONSEQUENSES FOR LOUISIANA AND EAST TEXAS AS MAJOR HURRICANE LAURA APPROACHES

Little has changed since my last post. It's just a lot worse. Laura's track still takes it close to the Louisiana/Texas border and the prediction of a major hurricane has not changed.

Watching the rapid intensification of this storm has been breath-taking, I am not sure if I have seen anything like this since Hurricane Wilma exploded into life in the south west Caribbean Sea back in 2005. Laura has gained wind speeds of about 70 mph in maybe 12 hours (now at 145mph and rising) and is pushing Category 5 status ... that is historic.

It is historic also for Louisiana. The storm surge will be on the central and eastern side of the hurricane as it makes landfall on the border of Louisiana and Texas. This is low lying land and predictions indicate the storm surge could engulf land up to 30 miles from the coast with estimated surges of 20+ feet in some coastal areas.

Then the rain ... 10 inches, 15 inches here and there.

Then the wind field ... the hurricane force winds could extend 200 miles from the centre, mostly on the eastern side.

The west Texas coast will take impacts but the greatest impacts will be on the coast of Louisiana and all the way east to the Mississippi Basin.

This is not a good time to be in Louisiana, even if you are a storm chaser so don't be daft!! I hope all residents in the risk areas are now safe and sound. There have been some introductory squally rain bands affecting Louisiana and if you think that is bad then you need to get really very really very ready !! ... Louisiana is about to experience a storm of historic and medieval proportions tonight and early tomorrow.

I hope everyone there is safe (including the idiotic storm chasers).

Regards

[Paul Tallet]

LAURA AND 2 NEW DISTURBANCES ON THE WAY

Hurricane Laura came within a puff of reaching Category 5 status as it made landfall in Louisiana. From the initial reports it seems that the 'un-survivable' storm surge was over-estimated but that's a good thing if it got people away from the affected areas because there was danger with the wind speeds and the heavy rain. Some stayed behind and I hope that there were minimal casualties.

Laura has now weakened considerably to a tropical storm but the storm's energy will remain as it travels east-north-east across the US before emerging into the northern Atlantic near Canada. The UK Met Office is watching Laura and running the models to determine if this energy could add strength to another named storm for Ireland and the UK, having had 2 unseasonal named storms already ... all I could do was watch hopelessly as the storms destroyed my prize dahlias ... bloody weather!

Anyway, there are 2 new disturbances moving across the tropical Atlantic. Again, these may not develop much before they reach the Caribbean but they will be noticed as strong tropical waves at the very least. The nearest disturbance is following Marco's track and this will be of interest to Tobago and the southern half of the Caribbean. The next one is following an almost identical track as Laura.

At this stage of the peaking (?) season these 2 disturbances need watching so be prepared and I will post an update tomorrow.

Regards

[Paul Tallet]

2 DISTURBANCES

I said I would update yesterday but little has changed apart from the leading disturbance getting closer to the Caribbean.

This one is unlikely to develop but it is starting to turn and will bring rains and squalls to Tobago and the eastern Caribbean from late Sunday to Monday.

The other one is staying close to and south of the Cabo Verde Islands and not moving that much. This one looks likeliest to develop before it completes it's journey across the tropical Atlantic.

It is worth bearing in mind that the season, so far, has been incredibly active in the tropical Atlantic up to latitude 20 in terms of moisture, low shear and cooking sea temperatures. These favourable conditions can lead to a quick detonation of these disturbances in a short period of time, however the only limiter is the dry Saharan air layer which I expect will recede during September and October.

We should not forget how quickly Laura developed last week when the hurricane found warm and deep waters in the Gulf and once a hurricane becomes as well developed as that it is much harder for the negative factors to break it down.

Regards

[Paul Tallet]

4 DISTURBANCES

It is really kicking off now.

A disturbance just off the east coast of Florida has a 70% chance of development according to the NHC.

The system that has just passed Tobago and the eastern Caribbean is starting to crank up and the NHC rates this as an 80% chance.

There are 2 additional systems to watch in the tropical Atlantic, one of which has not left Africa yet. In these conditions, hurricanes can develop and intensify very quickly and unexpectedly.

Shaping up to be another 2005 season. So everywhere in the Caribbean should keep an eyeball on the situation.

Updates to follow ...

Regards

[Paul Tallet]

TD 15; TS NANA, BELIZE & 2 OTHER AREAS OF CONCERN

Tropical Depression 15 formed yesterday off the east coast of Florida and the Carolinas ... this may reach tropical storm status but does not pose any threats to land.

The 2 areas of concern are in the tropical Atlantic and have some way to go but there is a good possibility that the Caribbean will be impacted by these late weekend or early next week.

Nana is the one to watch, approaching Belize. This is a very small storm and, being small, is unpredictable in terms of it's strength. The NHC see a hurricane just off the coast of Belize by Thursday but it could be more or less than that. The key point is the size of the wind-field which is small and likely to affect a small area, however the rainfall impacts will be more widespread.

Belize does not get many direct impacts from storms because the land mass of Nicaragua tends to protect it. However, the vast Coral reef of Belize has a number of low lying islands that would be impacted badly by any storm surge. So anyone residing or holidaying on those islands would do well to evacuate, although that very much depends on the communications there ... I would say that 36 hours from now is the latest opportunity to leave the Islands and that is pushing it a bit.

Nana needs watching carefully before we turn our attentions to the trouble brewing at the east end of the Atlantic tropics.

Regards

[Paul Tallet]

5 STORMS OR DISTURBANCES AND THUNDERSTORMS BREAKING OUT ACROSS THE CARIBBEAN

I think we can be confident that the season is beginning to peak.

I will start in the west and go east ...

Tropical Storm Nana managed to make hurricane status just before landfall in Belize but, as I suggested in my last post, the hurricane conditions did not extend more than 10 miles away from the centre of this small storm. The storm is now dumping plentiful rains over Guatemala and is likely to dissipate before it reaches the Pacific coast. Plenty of thunderstorms are still around in the western Caribbean due to the moist / humid conditions.

Across the rest of the Caribbean thunderstorms are breaking out almost everywhere although the northern Gulf is relatively clear.

Tropical Storm Omar is a weakening storm that is now downgraded to a tropical depression and is part of a streamer of moisture outflowing from the tropics towards the UK and northern Europe and could bring some rainfall impacts to these areas over the next several days.

The Atlantic High is weak and should provide little resistance to the 3 disturbances in the eastern tropical Atlantic if they start to spin and gain latitude. It is possible that all 3 could curve north and not affect any land but I think that theory is too good to be true. The 2 leading disturbances have a 40% and 70% chance of developing according to the NHC and the 3rd disturbance has yet to leave the African coast.

This area is a hotbed of prime conditions for storm development and I am expecting significant activity during the rest of September.

Regards

[Paul Tallet]

BIG WEEK AHEAD

We still have a weak Tropical Depression Omar hanging on in the mid Atlantic and a new disturbance has developed in the Caribbean Sea south of Puerto Rico which does not look like doing much other than bring heavy rains to Jamaica, but worth watching.

My focus is now on the eastern tropical Atlantic. A large area of potential spinners have started to get organised just west of the Cabo Verde Islands and the NHC is giving this a 90% chance of development. Another strong development is about to emerge off Africa and the NHC is giving this an 80% chance already. And there is yet another one behind that.

It is looking likely that we could have 3 Cabo Verde storms in the Atlantic later this week and I expect that 2 of them will reach hurricane status. The big question is where they will go.

The Atlantic High is quite a weak influence right now and this could cause a storm to gain more latitude and become a fish storm in the mid northern Atlantic, however the High pressure is expected to ridge further south this week and this could guide the storms into a more westerly direction, threatening land on the other side of the Atlantic.

So there is a lot to watch this week and I am sure updates will follow ...

Regards

[Paul Tallet]

2020 HURRICANE SEASON IS DETONATING!

Since my last post I have made regular visits to the NHC website, looked at sat loops, considered both professional and amateur weather forecaster opinions and studied the weather models and by the time I have come to summarise all this and post an update, something has changed.

In a word ... Chaos.

This is an extremely active season and disturbances are popping up everywhere in the tropical Atlantic. Some are being snuffed out by a patch of dry air or a cool pool of sea water but there have been between 5 and 8 disturbances or storms on most of the last 5 days.

With this much activity I could write a book but I am going to focus on the activity that poses the greatest threat to the Caribbean, the US ... actually erm ... all of the North Atlantic.

Firstly, we have 2 tropical storms Paulette and Rene. Both are expected to reach hurricane status shortly (which will match my prediction last weekend) and the riskiest of these 2 systems is Paulette that could impact Bermuda as a slow moving hurricane by late Sunday and through Monday and possibly Tuesday. There is some spread in the potential track which depends largely on the Atlantic High strengthening or weakening. Strengthening could push Paulette further west and avoiding Bermuda, if this is significant, Paulette could go close to the US east coast. Another key factor will be strong sea swells pushing south westwards towards the Caribbean and along the Florida east coast.

The next problem is a small disturbance just east of the Bahamas. The NHC have labelled this disturbance 1. This is trying to spin and it may have some success as it travels west across the Bahamas, Florida and into the Gulf where it could not have a better welcome ... this one could explode if the conditions are right ... so all Gulf coasts should be watching this one.

Back to the tropical Atlantic ... I have already mentioned Paulette and Rene that are leading the charge. 3, yes 3, more are bringing up the rear and 2 of these have not left Africa yet.

The one to watch has just left the African coast at a relatively low latitude and the NHC (labelling it as Disturbance 3) are giving this a 90% chance of development. This is a big circulation that will take some time to get cranked up and this ups the odds on it staying on a more westerly track and only gaining latitude when it starts spinning. However, as said earlier, will the Atlantic High strengthen? If it does then that is another contributor to a westerly track ... the whole of the Caribbean needs to watch this ... I see the potential for a large and major hurricane from this particular disturbance.

And it does not end there ... if you look at the position of the ITCZ over the last week you will notice that it is sinking south and that means that future developments will spawn further south which increases the risks for the Caribbean.

I must stress that this is a particularly active season and all interests across the whole of the Atlantic as far north as the Arctic Circle should observe developments regularly because, even if there is not a direct hit, these potentially violent disturbances can kink jet streams or add energy to extra tropical systems over wider areas. Don't think you are out of it !!

The next one is Sally ... who is taking bets on reaching the Greek Alphabet? The last time that happened was in 2005.

Updates will inevitably follow ...

Regards

[Paul Tallet]

PAULETTE; RENE; SALLY; TD20 & 2 MORE DISTURBANCES
TROPICAL ATLANTIC GOING BONKERS

I will focus on the threats most.

Tropical Storm Sally ... Since my last post, my prediction about Disturbance 1 has proved correct now that it has strengthened and developed into Tropical Storm Sally. Initially the global models had not even picked this disturbance up and the NHC deserves credit for doing so. Sally is expected to move slowly west across the southern tip of the Florida peninsula and onwards through the northern Gulf towards landfall around the Louisiana / Mississippi border as a hurricane. New Orleans is currently in the crosshairs.

Currently, Sally is a sheared storm with it's centre north west of the main storm cluster, however once the land interaction is over and the storm moves over the cooking Gulf waters it is likely going to get it's act together and it could, in my opinion, become a major hurricane as it traverses most of the northern Gulf coast, dumping copious rains over the land before finally making it's landfall. Please note that a lack of steering currents will slow Sally down and this means larger rainfall volumes and extended hurricane conditions where the centre of Sally interacts with land areas.

Global models are still conservative about this storm and they may be right if the track takes a more northerly direction but I would say that a track taking the centre of the storm over New Orleans on Tuesday offers the most damaging consequences.

Tropical Storm Paulette ... on the verge of hurricane status, is also slowing down and could become a major hurricane for Bermuda late Sunday night before it turns sharply to the north east and speeds off into the northern Atlantic. Because Paulette is slowing down then hurricane conditions could affect Bermuda for 12 hours or more.

Former tropical Storm Rene is weakening and poses no threat.

Tropical Depression 20 I suggested could be a concern for the Caribbean however it is looking increasingly likely that this storm will, as a hurricane, turn north before it gets there thanks to a ridge of high pressure forming over the north east Caribbean. I stress likelihoods and not certainties so this development still needs to be watched.

Further threats are expected to come off the African coast and smaller developments could pop up within the Caribbean Sea and it will be interesting to see what Hurricane Paulette does to the weather patterns in the north Atlantic towards the end of next week.

Regards

[Paul Tallet]

SALLY; PAULETTE; 5 OTHER DISTURBANCES

As before, I will focus on the threats as follows:-

Tropical Storm Sally is strengthening and on the verge of hurricane status. the storm is close enough to the northern Gulf coast for impacts to commence but this is likely to go on for a few days as Sally slows right down and landfall could be painfully slow, affecting a wider area along the coast. It is very difficult to be precise about the landfall anymore but coastal regions to the east of Sally's centre could be just as badly affected so we can be assured that impacts will be widespread and prolonged.

Hurricane Paulette is currently giving Bermuda a spanking with a direct hit over the Islands. Bermuda is known for it's resilience and Paulette is moving a little faster than Sally. After Bermuda, Sally will turn to the north east and I am watching this to see if there are any impacts for Europe further down the timeline.

Tropical Depression 20 is no longer going for the Caribbean and may not affect any land areas but it is expected to become a major hurricane in open water, sending strong sea swells across the Caribbean.

A new Disturbance 3 has just emerged off Africa and this is giving us early concerns that, like TD 20, it could track west towards the Caribbean. It is too early to say so this one needs watching.

I have covered 4 out of 7 disturbances in the Caribbean and Atlantic. Every tropical wave coming off Africa has developed in one way or another over the last 2 weeks so it is a busy time.

Regards

[Hugh S]

Obviously the Guardian is consulting Paul.

https://www.theguardian.com/world/2020/ ... torm-sally

[Paul Tallet]

HURRICANE SALLY
HURRICANE PAULETTE
TROPICAL STORM TEDDY
TROPICAL STORM VICKY
EX-TROPICAL STORM RENE
PLUS 2 OTHER DISTURBANCES

Thank you Hugh ... the Guardian fleshed it out a bit don't you think?

This is just a brief update on Hurricane Sally which has slowed down to such an extent that the storm could weaken if it hangs over the same waters for too long. Hurricanes are cooling systems and if Sally churns the same area of sea for more than 18 - 24 hours the sea will cool and deprive the hurricane of the energy it needs.

If Sally moves a little the hurricane could strengthen rapidly.

Sally is also meandering (or dithering) and shifted a little to the east which may be good news for New Orleans, however, if the hurricane curves eastwards under the steering influence of a trough to the north then a prolonged landfall could drag along the Alabama and north west Florida coasts ... this would be a bad outcome.

This is mere speculation on my part and you won't get an assured answer off the weather forecasters because the situation is very fluid ... regardless, major impacts can be expected across a vast swathe of the northern Gulf coastline.

Regards