2018 Atlantic hurricane season officially begins

The fist 10 days of the official start to the season are usually quiet but we do need to watch the western Caribbean, Gulf of Mexico and the southwest Atlantic for signs of development as the month wears on.

The fist 10 days of the official start to the season are usually quiet but we do need to watch the western Caribbean, Gulf of Mexico and the southwest Atlantic for signs of development as the month wears on. Tap or click for full-size image.

As you know, we have already had a named storm – Alberto – even though it was outside of the normal window that we call “hurricane season”. It was also classified as being subtropical in its structure but I think that will be changed in post-season analysis. Does the presence of Alberto mean the season will be busier or more problematic than usual? Not really. Although, I am intrigued at how well it maintained itself, and even became better structured, while over land. Perhaps this gives us a glimpse in to the future of how other systems will behave near or inland over the United States this season. Something to consider but overall, Alberto was a product of the pattern, not a symptom that something is amiss as we enter the official start to the season.

The list of names we are using this year are the same ones from 2012 except for Sara which replaced Sandy for obvious reasons. The next name on the list this season will be Beryl followed by Chris, Debby, Ernesto and so on. The general consensus is that we will use between 12 and 14 names this season; we’ve already used one, so we shall see.

This time of the season, we usually look to the Gulf of Mexico, western Caribbean Sea or the southwest Atlantic for signs of development. The deep tropics, or what we call the Main Development Region, is almost never favorable in June due to higher pressures, lower SSTs and generally fast trade winds. It’s not until August that we typically watch the eastern Atlantic for development but you never know…there’s always a first time. For the most part, however, June is considered a slow month for Atlantic hurricane activity.

My plan this season is to continue to do what I have done for the better part of two decades: provide easy to understand, matter of fact updates about the tropics. If there’s nothing going on, then that’s what I will say. If I see something that worries me, I will say that too. In between, we will work on learning more together and I will use my 22 years experience to help you better understand not only what may or may not happen in the tropics, but also what to do about it should something head your way. We all have a role to play, it’s not up to the government to do it for us. I’ll help in what ever capacity that I can but will often refer you to other experts who know more than I do or who may have a different take on a certain aspect of what we’re dealing with. Preaching down to you as if I am beyond learning will never happen. When I stop learning, I will retire and write a nice long book. Until then, let’s get through the 2018 hurricane season together using the tools that we have and the collective trust that we have in each other.

Program note: this evening at 7:30 pm ET I will be live on my YouTube channel and hopefully on Facebook live as well to gather ’round the campfire, so to speak, and talk about the season. It will be like a gathering of friends, some old, some new, who have like-minded interests. In this case, it’s hurricanes and how we deal with them. I’ll have some tee shirts to give away plus a very special opportunity to own a piece of history. I will also take questions via email, Twitter, our own HurricaneTrack Insider chat, YouTube chat and (hopefully) Facebook comments. It should be fun which is what friends do when they get together. Hurricanes are tough, getting ahead of the curve shouldn’t be and it shouldn’t be all doom and gloom either. Weather is exciting and often beautiful – yet we know that tropical storms and hurricanes are dangerous, especially if not respected and understood. I think we can do a lot together and this evening we begin that journey. I call it “Day 1”. I’ll embed the YouTube feed here at 7:30 pm and will Tweet the link as well. Follow via YouTube and Facebook for instant notifications: search “hurricanetrack” and look for my logo.

M. Sudduth

8:35 AM ET June 1

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MJO taking a vacation so tropics will remain quiet

MJO current and forecast position by various computer models. Right now, the MJO is of little amplitude and is not contributing to tropical convection anywhere around the world.

MJO current and forecast position by various computer models. Right now, the MJO is of little amplitude and is not contributing to tropical convection anywhere around the world.

After the brief life-span of TS Chantal, the tropics are now quiet again. Part of the reason behind this is climatology: the tropics are generally very quiet during this period of July. The other reason is the MJO or Madden-Julian Oscillation. Think of the MJO as a period of fertility in the tropics. When the MJO is present, upward motion or tropical convection usually blooms and often leads to tropical cyclone formation during summer months. On the flip side, when the dry phase of the MJO rolls around, the air is converging and sinking, not allowing much tropical convection to occur. While it’s possible to have tropical cyclones form during the dry phase of the MJO, experience shows that a favorable MJO pulse often leads to the development of tropical storms and hurricanes. Right now, the MJO for the Atlantic Basin is taking some time off.

In fact, the MJO is not really amplified anywhere across the globe at the moment and as such, the tropics world-wide are generally quiet. There is one area of growing convection in the west Pacific that has a chance of developing in the coming days but that’s it. Without an amplified MJO pulse, it looks like the next several days at least will be nice and quiet. I see nothing of concern within the global models over the next week to 10 days. Once we get in to August, climatology begins to shift and it is possible that another favorable MJO pulse will coincide with that shift and things should be quite busy later in the month. For now, enjoy the calm conditions while they last.

M. Sudduth

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As peak of season nears, no major impacts expected

Atlantic Hurricane Season Climatology

Atlantic Hurricane Season Climatology

We are almost to the half-way point of the hurricane season, at least from a climatological perspective. Over the past 100 years of all tropical cyclones, it seems that September 10 is the tip of iceberg and this year, it will be no different. We have two named storms out there with Leslie and Michael as well as a new area of interest, 91L, just off the coast of Africa. The peak of the season will indeed be a busy one this year.

However, the impacts from all of this activity will likely be minimal. Leslie is still struggling and should pass Bermuda well to the east, bringing only passing showers and a few squalls at most. Of course, the surf will be up, but that’s the extent of it and certainly great news for Bermuda. It also looks like Newfoundland will escape any major impacts from Leslie as the forecast for track and intensity are much more favorable than what it looked like a few days ago.

The rest of the tropics are busy but I do not see any threats to land from anything over the next five days at least. In fact, the MJO is quite unfavorable right now which means sinking, converging air over much of the western Atlantic Basin. We should see a nice quiet period before things ramp up again towards the last half of the month.

I’ll have more here tomorrow. Be sure to check the HurricaneTrack app for today’s video blog which covers all of the above-mentioned info. Don’t have our app? Get it now from the app store.

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Warmer than normal water temps likely to fuel Leslie as rest of tropics stay very busy

Atlantic Sea Surface Temperature Anomalies

Atlantic Sea Surface Temperature Anomalies

Sea surface temps are running at least one degree Celsius above normal across much of the northwest Atlantic. In fact, there are large areas of plus two and three Celsius just off the Canadian Maritimes. This translates in to added heat content and Leslie is poised to take advantage of it over the next week or more.

The current NHC forecast track has Leslie moving very slowly over the next few days as steering currents remain weak. The track takes the center just to the west of Bermuda but since Leslie is a large storm with a huge wind field, the effects will be felt on the island in the way of large, battering waves, heavy rain and high winds. I suspect it won’t be too much longer until we see a hurricane watch posted for the island.

With all of this warmer than normal water around, Leslie looks like it could strengthen in to quite a strong hurricane in the models. Add to this what appears to be a very favorable upper level outflow pattern and it is possible that Leslie becomes the first category three hurricane of the season. We have been in this pattern of seeing storms/hurricanes intensify out of the deep tropics and I don’t see any reason to believe that Leslie will be any different.

In the longer range, the Euro continues its westward forecast for Leslie, taking it very close to Nova Scotia and Newfoundland. Any further west and we could be looking at a possible brush with portions of New England as well. Much of this will have to do with the way a trough is supposed to develop in the Tennessee Valley this weekend and beyond. If it is weaker or digs in farther west, even by a little, then the high pressure area over the western Atlantic can build in more and push Leslie a degree or two of longitude west. I will be watching closely to see if this trough acts to capture Leslie and swing it north-northwest or whether the trough acts to push Leslie out to the north-northeast. How this plays out will determine what, if any, landmass is directly impacted.

One effect that I have made mention of for several days now is the increasing swells that will roll in to the East Coast. The NHC continues to make mention of this in their discussions and I want to emphasize the importance of understanding how dangerous rough surf can be- even with a storm/hurricane hundreds of miles off the coast. Check out this video that I produced last year as part of a preparedness campaign with Olympus Insurance out of Florida:

Elsewhere, we now have tropical storm Michael which will be officially named at 11am ET on the NHC advisory. The small storm will be short-lived and not affect land but it will bring the total number of named storms to 13 this season. While Michael is much smaller than Leslie, it is clearly a tropical storm and is of interest to shipping lanes in the open Atlantic.

The east Pacific is calming down and I do not see any new areas of concern developing anytime soon.

I will be working on the daily video blog for our iPhone app and will have it uploaded in just a little while. We are also eagerly anticipating the first major update to the app any day now. The update will greatly enhance the app and allow for manual refresh of the video blogs. As soon as it is approved by Apple, I will add a separate blog post. Speaking of blogs, I’ll update this blog later this afternoon.

 

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Bermuda could be impacted by Leslie as September looks to be quite busy due to lack of El Nino

Leslie Could Impact Bermuda This Weekend

Leslie Could Impact Bermuda This Weekend

TS Leslie developed some very deep convection over night with cloud tops reach an astonishing -88 degrees Celsius. Those cold cloud tops, however, did not wrap all the way around the center of the storm. This is due to the continuation of vertical wind shear which has been just enough to keep Leslie from strengthening much. I do think the burst of deep convection is a sign that Leslie will intensify given the right upper level conditions.

The current forecast track has not budged much from recent ones and it looks like a slow and steady course to the north-northwest throughout the week ahead makes the most sense considering the pattern. There will simply not be enough western Atlantic ridge to push Leslie back to the west enough to directly impact the U.S. That being said, I do believe that an increase in long period swells is coming – especially once Leslie becomes a hurricane. Its slow movement will allow for quite a build-up of energy in the ocean and this means a great surf weekend coming up for portions of the East Coast. It also means an increase in rip currents and as such, people heading to the beach need to be mindful of this hazard. We are still a few days away from the swells reaching the U.S. and I will address this again later in the week.

As for Bermuda, it looks as though Leslie could come fairly close to the island by the weekend as a strong hurricane. Some of the intensity models suggest that Leslie could approach or exceed category three intensity towards the end of the week. Interests in Bermuda need to pay close attention to the future track and strength of this storm. It also looks like Leslie will be quite large with an expanding wind field so even a brush with Bermuda could mean a period of high winds and very rough seas for the area.

Looking at the rest of the tropics, we have invest area 99L well out in the east-central Atlantic. It may develop some but is small in size and poses no threat to land areas.

In the eastern Pacific, TS John has formed to the southwest of the Baja peninsula and will move swiftly off to the northwest and not be a bother to Mexico.

SST Anomalies from August 3

SST Anomalies from August 3

Checking on the current state of the El Nino, we see that it has, in fact, backed off quite a bit in recent weeks. Comparing the SST anomaly maps from August 2 and the one from today, it is clear that the warming trend has stopped and even reversed in the eastern Pacific. This means that the threat of a significant El Nino event during the hurricane season is likely minimal at best. In other words, the negative conditions that a Pacific El Nino would typically bring to the Atlantic Basin are probably not going to be there.

SST Anomalies from September 3, Notice the Decrese in SST Temps in the East Pacific

SST Anomalies from September 3, Notice the Decrese in SST Temps in the East Pacific

The reason El Nino affects the Atlantic is similar to how a large hurricane, with its well established outflow, affects other tropical waves moving across the Atlantic. Remember TS Jean which formed east of Isaac? The large scale upward motion of Isaac led to strong outflow high in the atmosphere and this literally tore Jean apart and caused it to weaken and dissipate. An El Nino event, especially strong ones, causes tropical convection to persist across a good deal of the Pacific. This upward motion on a basin-wide scale acts to spread strong upper level winds across the deep tropics of the Atlantic, much like the outflow from a hurricane. This shear stops developing Atlantic systems in their tracks. Because we are not seeing a significant El Nino event taking shape right now, I suspect that September will be quite busy with a shift in activity more towards the Caribbean Sea and Gulf of Mexico. This is a natural evolution in any season when we see the tropical waves that come off of Africa lose their punch and the build up of low pressure in the western part of the Atlantic and Caribbean leads to development there.

The long range models, and we’re talking beyond 10 days here, indicate this pattern change is coming. Once Leslie moves out, we will probably only wait a few days, if that, before we have yet another named storm.

Curiously though, we have yet to have a major hurricane this season in the Atlantic. The layer of persistent dry air has really put a lid on things, literally. I think that Leslie has a chance to become a category three hurricane as it nears Bermuda as the global models indicate what looks like a favorable upper level wind pattern for it to develop. We may have had a lot of activity, but no intense hurricanes just yet.

I will go over a lot of what I have outlined here in today’s edition of the Hurricane Outlook and Discussion video for our iPhone app. I will also post an update here in the blog this evening to reflect the very latest on Leslie and whether or not I may be taking a trip to Bermuda later this week.

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