Hurricane season nears: El Nino not likely to be a factor but warm Atlantic could be

We are closing in on the 2017 Atlantic hurricane season and thus far, it look as though El Nino will not do much to limit activity. On the other hand, the tropical Atlantic has warmed up quite a bit since early spring and this might be the tipping point that gets us in to an active season once again. I cover this and more in my latest video discussion posted below:

M. Sudduth May 22, 2017

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If El Niño is coming, it will likely be too little, too late

Mid-March ENSO forecast showing a high probability of El Nino conditions setting in by the summer months.

Mid-March ENSO forecast showing a high probability of El Nino conditions setting in by the summer months. Click for full size image.

There was a lot of talk about the resurgence of El Niño just a couple of months ago and it looked as though we were in fact heading in that direction. This would have been unusual to see since we just had a substantial El Niño or warm ENSO event back in 2015.

The presence of El Niño is also a known detriment to Atlantic hurricane activity, especially in the deep tropics. As such, most of the reliable seasonal forecast agencies were calling for less activity than we saw in 2016.

So where do we stand now? As we approach mid-May, the odds of El Niño are going down. There are some mechanisms in place to get it started but so far, it’s stalling out of the gate.

Latest subsruface anomaly chart showing only limited warming overall and nothing significant at the surface of the tropical Pacific

Latest subsurface anomaly chart showing only limited warming overall and nothing significant at the surface of the tropical Pacific. Click for full size image.

Take a look at the latest subsurface anomaly chart and you’ll see what I mean. The top of the chart is the surface of the tropical Pacific while the bottom represents more than 400 meters of depth. While there is a large “blob” of positive anomalies showing up, it is no where near as substantial as what we saw in 2015. Furthermore, it is not strengthening and being reinforced by more warm water from the western Pacific. Instead, the tropical Pacific as a whole is in a neutral state – neither too warm nor too cold right now.

The latest climate models have backed off quite a bit in recent weeks with regards to warming of the tropical Pacific. Just a month ago, it appeared that we had a near 70% chance of seeing El Niño conditions by August/Sept/Oct – now that probability has dropped to 46% according to the latest update from the Climate Prediction Center. What happened? The easy answer is that spring is usually a difficult time for the climate models to resolve what will happen with the ocean/atmosphere state several months down the road. A more complicated answer lies in the fact that there are still many mysteries surrounding the evolution of ENSO or El Niño-Southern Oscillation as it is often referred to. Sometimes we get El Niño and sometimes we don’t and the reasons why are still unclear.

Mid-May climate models have backed off the chances of El Nino quite a bit.

May climate models have backed off the chances of El Nino quite a bit.

What is becoming increasingly clear, however, is the fact that for the 2017 Atlantic hurricane season, El Niño isn’t likely to be a factor. This puts a check mark in the enhancing column for seasonal activity but the absence of El Niño alone is no guarantee of a busy season. That being said, there are recent developments in the climate models for the summer months that suggest the Atlantic Basin could be more favorable than we have seen in quite some time.

As of today, much of the deep tropics between Africa and the Lesser Antilles are warmer than normal while the subtropical Atlantic has cooled dramatically. This would tend to focus lower pressures and more favorable conditions right where we’d expect it to be – the deep tropics. While this can change, it appears that we will begin the 2017 season with no El Niño and a warmer than normal tropical Atlantic. I think it is a safe bet that for those who issue seasonal forecasts, their numbers will go up in the coming weeks.

SST anomalies have gone up in the deep tropics in recent weeks, a sign of possible higher hurricane activity during the season ahead.

SST anomalies have gone up in the deep tropics in recent weeks, a sign of possible higher hurricane activity during the season ahead.

Numbers aside, it is important to note that no one can predict where whatever does form will end up, if anywhere at all. A season like 2010 had plenty of hurricane activity but not a single one crossed the U.S. coastline. On the other hand, a season like 1992 had one significant hurricane – just one. And as they say, that’s all it took. We live in very different times than we did 10-12 years ago and that is not just hyperbole, it’s true. The advent of social media, the rise of so-called “fake news” and other political distractions mean that it is literally up to you, on a very personal level, to learn all you can about your local vulnerability to hurricane impacts. We could have 2 hurricanes form this season or 12, no one knows for sure. What really matters is where they end up and if that is your backyard, you will be doing yourself and your family a favor by being ready.

I will have much more on the coming season during a special live broadcast via YouTube Live on Thursday, June 1 at 7pm ET. Until then, get ready, hurricane season is coming – just like it does every year around this time. No reason to ignore it or act like the sky is falling, we should be prepare the same year in and year out.

M. Sudduth 8:50 AM ET May 12

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East Pacific hurricane season will begin a little early this year

Latest model plot showing the likely track of invest area 90-E in the eastern Pacific

Latest model plot showing the likely track of invest area 90-E in the eastern Pacific

Officially, the east Pacific hurricane season gets going on May 15. That’s the date on a calendar – Mother Nature often strays from such notions and this year will be no exception.

The NHC is monitoring an area of low pressure, known as invest area 90-E (the “E” is for east Pacific) well off the coast of Central America and southeast Mexico. It is forecast to go on to develop in to a tropical depression and will likely become the east Pacific’s first named storm: Adrian.

Fortunately, the model guidance suggests a track that would keep much of the inclement weather offshore with only minimal impacts, if any, being felt on land. It’s something to keep an eye on for sure but nothing to be too concerned with just yet.

Let it also serve as a reminder that hurricane season is nearing – not only for the east Pacific, but also for the Atlantic Basin. That being said, it is Hurricane Preparedness Week and I encourage you to visit the updated section of the NHC’s site to learn what you can about tropical storms and hurricanes. There’s always something new, so even if you’re an avid weather geek who thinks they know a lot, might as well brush up your knowledge base and check out the latest from the NHC here.

I’ll have more on invest 90-E later this afternoon during my video discussion which will be posted to YouTube and here.

M. Sudduth 8:55 AM ET May 9

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As hurricane season nears, odds of El Nino being a factor diminishing

Will El Nino be enough to affect Atlantic hurricane season? I highly doubt it and will show why in today’s video discussion. Plus – the east Pacific hurricane season officially begins in a week but we are watching invest area 90-E for likely development as the week progresses. A lot to go over, check it out!
M. Sudduth 5pm ET May 8
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Pre-season storm forms way out in the Atlantic – but how & why?

TS Arlene

TS Arlene

We’re approaching the end of April and we have the year’s first tropical storm to track: Arlene.

First – a little history….

The Arlene of 12 years ago (wow, has it really been that long?) made landfall just west of Pensacola, FL on June 11 as a weakening but fairly well organized tropical storm. I was there along with colleague Mike Watkins (we began in Destin and made our way over to Gulf Shores, AL). The 2005 version of Arlene had plenty of warm Gulf of Mexico water to work with and had it not been for strong upper level winds, common in the early portion of the hurricane season, it would have easily become a hurricane. Check out this archive video from our 2005 documentary: TS Arlene in 2005 from our Tracking the Hurricanes: 2005 documentary

Fast forward 12 years and we have Arlene again. First of all, names get re-used unless they have a reason to be retired and replaced from the list. Think of Andrew, Camille, Matthew and Katrina as examples – major events usually mean a name will be replaced. So far, Arlene has not had such an infamous fate and this iteration of it will be no different.

However, what is fascinating is how Arlene formed and where it formed.

We know that tropical storms and especially hurricanes “like” warm water, say around 80F or so. While this is generally true it is not an absolute must-have ingredient. Warm, tropical water certainly provides more latent heat for a tropical storm or hurricane to tap in to but that is just one mechanism that we see to drive the deep convection that keeps the heat engine going. There are other ways to drive the thunderstorms around the center of circulation, even over cooler water such as what we are observing in the case of 2017’s Arlene where sea surface temps are close to 70F at best.

To better explain it, here is a quote from NWS meteorologist Tony Cristaldi:

“[to help you understand how]  a “true” TC is able to form over sub-26C (80F) water: That objective temp has a HUGE underlying assumption that temps aloft (500MB and up) are typical of those seen over the MDR during the traditional TC season. Obviously, Arlene, and other high(er) latitude systems, including “Medcanes”, feature not only colder SSTs/near surface air temps, but also much colder temps aloft. As long as the air mass lapse rates are conditionally unstable, there exists sufficient moisture, and wind shear is not prohibitive, then “tropical” type cyclone development can and does sometimes occur.”

Basically, the environment that created Arlene is unstable enough to allow the limited but persistent convection to wrap around the center and give us the true (albeit marginal) look of a tropical storm. Bottom line is that to get the powerful deep tropics hurricanes that we’re used to seeing, yes you need deep warm water, light shear and ample moisture in the mid-levels. For these out-of-season open ocean storms, not so much; Arlene being a prime example.

Does it mean a busy hurricane season ahead? I highly doubt it. The pocket of energy that became Arlene did not originate from the deep tropics but instead came from a mid-latitude source. If we were to see a true tropical wave emerge from Africa and manage to develop in to a tropical storm or especially a hurricane, then THAT would have significance. Instead, Arlene is just a novelty and something for shipping interests and weather geeks to keep watch of.

I’ll have a video discussion posted covering Arlene tomorrow morning.

M. Sudduth 10:55 pm ET April 20

 

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