One ingredient is in place: very warm ocean temps

As we all know by now, it takes a very specific set of ingredients coming together at the right time to produce tropical cyclones – and in our case, hurricanes. Sometimes all of the pieces are seemingly there, yet nothing happens. One key element of the whole process is warm water, there is no doubt about that. Warm water, usually around 80F or higher, is what fuels hurricanes and the warmer it is, the stronger they can become.

Sea surface temperature anomalies (departure from normal) showing a very warm western Atlantic, Gulf and Caribbean Sea. Contrast this to the cooling tropical Pacific and it could make for a busy August-October for hurricanes in the Atlantic.

Sea surface temperature anomalies (departure from normal) showing a very warm western Atlantic, Gulf and Caribbean Sea. Contrast this to the cooling tropical Pacific and it could make for a busy August-October for hurricanes in the Atlantic.

This year, water temps in the western portion of the Atlantic Basin are warmer than normal in most locations. Check out the very latest anomaly map which shows the departures from normal across the region. Clearly, the Gulf of Mexico sticks out as does the western Atlantic just off the Southeast coast. Also of note, the Caribbean Sea has several areas of positive anomalies – meaning that water temperatures are above normal.

Obviously, none of this will matter unless there is a hurricane to tap in to the vast energy stored in this warmer than normal water. Right now, I see nothing in the global models to indicate that anything will be developing in the near future – all of the action is in the east Pacific right now. In fact, I have a theory that with all of the constant hurricane activity between Hawaii and Mexico, perhaps the sea surface temps will be cooled enough to create a stark contrast between the Pacific and the Gulf of Mexico/Western Caribbean. This could create more favorable conditions later in the season for that region – we will just have to wait and see about that.

For now, the warm water is in place, there’s no doubt about that. Whether or not it becomes a factor during the heart of the season, still a month away from beginning, remains to be seen. It will be something to keep an eye on for sure.

I will have more later in the week.

M. Sudduth 1:40 PM ET July 18

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Hurricane Bertha: 1996

Hurricane Bertha on July 12, 1996

Hurricane Bertha on July 12, 1996

On this day, 20 years ago, hurricane Bertha made landfall in southeast North Carolina and with that, sealed my fate with a career “in the business”.

The early July hurricane made headlines as being quite strong for so early in the season – reaching category three intensity not far from Puerto Rico on July 9.

After a period of steady weakening up until July 11, Bertha found new life in the warm Gulf Stream just off the South Carolina coast and once upper level winds relaxed, the hurricane quickly strengthened to 105 mph. During the afternoon of July 12, Bertha made landfall north of Wrightsville Beach. It was the first of five hurricanes that would make landfall in the Cape Fear region between 1996 and 1999.

Photo of me, 20 years ago today, holding a Davis anemometer up to record wind speed at the Wrightsville Beach drawbridge as hurricane Bertha was about to make landfall

Photo of me, 20 years ago today, holding a Davis anemometer up to record wind speed at the Wrightsville Beach drawbridge as hurricane Bertha was about to make landfall

For me, Bertha was the opportunity to do something that I had always wanted to do. I took my Davis weather station to the foot of the draw bridge at Wrightsville Beach and walked out as far as I could to the open area near the top of the span. I held the anemometer as high above my head as possible to record wind speed. It was far from perfect and certainly not very scientific, but for someone who grew up glued to The Weather Channel, watching Dennis Smith, Jim Cantore, Jill Brown and others while they worked hurricanes of the past, it was my moment. The rain stung my cheeks. Lightning cracked the sky (yes it really did lightning as the outer bands moved on shore) and the wind did all it could to buffet me as I stood by myself on that bridge.

Within a minute or so, several reporters braved the elements and rushed out to interview me. Some asked if I were a storm chaser. Others wanted to know if I worked for NOAA. I answered simply with, “I just wanted to know how fast the wind was blowing”. This was enough to pique their interest. My picture was taken and it accompanied an article in the Winston-Salem Journal the next day (oh how I wish we had Twitter, etc back then).

The anemometer recorded a gust to 70 mph. To the reporters on the bridge that afternoon, this was gold. They had something they could report on other than the usual stuff about people boarding up, evacuations being ordered and so on. As non-scientific as it was, I had data. I knew that this moment would define the rest of my career and that the lack of accurate data at landfall was a problem. From that moment on, I have worked to develop ways to measure hurricanes at landfall, not only through scientific equipment but also through the use of unmanned video of storm surge and other effects. And to think, it all began on that bridge as hurricane Bertha inked its place in North Carolina’s hurricane history.

M. Sudduth 12:30 PM ET July 12

 

 

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It’s July – tropics are supposed to be quiet

Hurricane season climatology graph showing the slow progression towards the peak in September. The green arrow is where we are today - still a long way to go.

Hurricane season climatology graph showing the slow progression towards the peak in September. The green arrow is where we are today – still a long way to go.

I have seen a bit of an uptick in chatter on message boards and social media about how dead the Atlantic Basin is right now. In fact, there has been some talk suggesting that things are abnormally slow and that the season is destined to be quiet like the last few. While I won’t pretend to know the future, I do know the past and that can help us to understand why things are so quiet now – and why it probably won’t last.

First of all, it’s early July, not mid-September. Climatology speaks volumes and from that perspective, it is supposed to be tranquil across the Atlantic Basin right now. Take a look at the graph – it shows the season spread out over time with the peak being in September. The green arrow that I added shows where we are today. This is one of the least active periods of the hurricane season and for good reason: it has always been this way (with the exception of a few outlier years).

During this time of the year, surface pressures typically run higher than normal across the Atlantic as large outbreaks of Saharan dust and dry, stable air move off of Africa. Again, nothing unusual about this at all. It takes time for the season to evolve and get things in to alignment for the peak months ahead. Once in a while we will get a storm or hurricane to develop during what is normally an inactive period, but on average, this period of time during the season is usually tranquil.

One huge difference between this season and last is the change in SST anomalies in the Atlantic and the Pacific - very easy to spot those changes here.

One huge difference between this season and last is the change in SST anomalies in the Atlantic and the Pacific – very easy to spot those changes here.

Another aspect of this season that is different from last season is the absence of El Nino. In fact, much of the tropical Pacific, along the equatorial region, has water temps that are below normal now. While we are not quite in to La Nina conditions, the contrast between this year and last year is astounding. You can see this very clearly on the graphic I have posted here.

Notice the very warm Pacific this time last year and compare that with the Atlantic at the same time. Now we see how things have dramatically changed in just a year’s time. The result is a more favorable Atlantic Basin but it’s not ready yet. Climatology tells us that it takes time. While no one is eager to have a hurricane headed in their direction, some may be wondering why we aren’t seeing any just yet. I believe it is all a matter of time and once the pattern shifts and the pressures begin to fall across the Atlantic, we will see less dust, more convection, more active tropical wave and eventually, the hurricanes will come. Where they go is an entirely different story – I have no idea! We’ll just have to be prepared, won’t we?

Enjoy the weekend, stay cool out there and I’ll have more here on Monday.

M. Sudduth 10:40 AM ET July 8

 

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East Pacific stays busy, Atlantic quiet for now

East Pacific satellite photo showing dying tropical storm Agatha (small convective blob) along with strengthening tropical storm Blas which is forecast to become a powerful hurricane over the open Pacific

East Pacific satellite photo showing dying tropical storm Agatha (small convective blob) along with strengthening tropical storm Blas which is forecast to become a powerful hurricane over the open Pacific

It looks like we will see a parade of storms and hurricanes in the eastern Pacific over the coming days. Right now, we have TS Agatha which is weakening over cooler water and TS Blas which is about to become a hurricane. Both systems continue to remain well off the Mexican coastline and will have virtually no impact on land.

The recent burst of activity in the east Pacific can be partially attributed to a more favorable pattern overall that has allowed convection to develop and thrive. This phenomenon is called a convectively coupled Kelvin wave or CCKW. What is that you ask? It is difficult to explain but essentially it is an eastward moving wave of energy, bound by the equator to its south, that seems to enhance convection and vorticity (spin) in the atmosphere. Another way to look at it – the spark that lights the fire. Often times the passage of a CCKW will trigger the development of tropical waves as they progress across the ocean. In this case, the east Pacific took advantage of the passage and now we have two tropical cyclones and a third likely later this week. The good news is that none of the systems seem bound to affect land areas.

Will the CCKW make its way in to the western Caribbean and/or Atlantic and thus set up potential development there? So far, I am not seeing much evidence to support that. The global models all indicate generally quiet conditions over the Atlantic, Caribbean and Gulf for the next several days. This is not surprising considering that when the east Pacific is active, the Atlantic is usually not. It’s also early July and from a climatology perspective, we are not supposed to see much activity right now anyway.

Radar image showing the eye of hurricane Arthur and my location over the Oregon Inlet early in the morning of July 4, 2014

Radar image showing the eye of hurricane Arthur and my location over the Oregon Inlet early in the morning of July 4, 2014

In other news, it’s now been two years since a hurricane of any strength made landfall along the U.S. coastline. That hurricane was Arthur in the very early morning hours of July 4, 2014.

I was in the eye of the category two hurricane over the Oregon Inlet in fact where the wind was about as calm as could be for about 20 minutes. Arthur produced moderate storm surge flooding, in some cases 4 to 5 feet of it, along portions of the Outer Banks, mainly south of Oregon Inlet. The disruption to tourist season was a major issue but the area rebounded quickly and fortunately, no other hurricanes had direct influence on the Outer Banks that season.

I will cover Arthur’s anniversary and more in my video discussion which will be posted later this afternoon.

M. Sudduth 10:15 AM ET July 4

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Two storms in east Pacific – one forecast to become major hurricane

NHC map showing the positions of tropical storms Agatha (left) and Blas (right). Boh systems are forecast to remain well off the coast of Mexico.

NHC map showing the positions of tropical storms Agatha (left) and Blas (right). Boh systems are forecast to remain well off the coast of Mexico.

And just like that, we now have two tropical storms in the east Pacific. After a very quiet start to the season in that region, things have become quite busy as of late.

First up is tropical storm Agatha, situated about 1000 miles WSW of the Baja peninsula of Mexico. There’s not much to say about Agatha as it is forecast to weaken over cooler water during the next few days and obviously will not be a problem for land.

Next we have tropical storm Blas, also well offshore of the Mexican coastline. Top winds are 60 mph and Blas is forecast to reach hurricane intensity by tomorrow. After that time, conditions appear favorable for Blas to continue to grow in to a major hurricane with winds of at least 120 mph. Fortunately, the steering currents are such that no matter how strong it gets, it won’t affect land either. There could be some additional ocean swells generated by the hurricane, especially if it gets stronger than forecast. Outside of that, neither system will pose any threat to Mexico.

In the Atlantic Basin, sinking air and a fairly dominant Saharan Air Layer (SAL) are keeping things quiet for the time being. This is quite typical for July when surface pressures are generally high and these SAL outbreaks are common. I do not see anything in the global models to suggest development over the next five to seven days.

Enjoy the celebrations this weekend and tomorrow! Be safe out there – especially if traveling. I’ll have more here tomorrow afternoon.

M. Sudduth 12:30 PM July 3

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