Signs of change for 2016?

After a couple of false starts in recent years, a strong El Niño finally developed and is now firmly entrenched across a good portion of the equatorial tropical Pacific.

El Nino at its peak in the tropical Pacific

El Nino at its peak in the tropical Pacific

This El Niño event has led to a substantial increase in Northern Hemisphere tropical cyclone activity, mainly in the Pacific (obviously), increased storms for parts of western North America with more to come in the weeks ahead and a fairly wet pattern overall for much of the South and Southeast U.S.

The outlook from the various groups who monitor El Niño calls for a gradual weakening of this warm event  as we move in to 2016. In fact, there is some evidence in the long range climate models that perhaps a cooling phase of what is called ENSO (El Niño Southern Ocscillation) is in store by 2017, if not sooner.

Once past the winter and the influence of the current El Niño, things begin to look very interesting for next hurricane season for the Atlantic.

One glaring consequence of this year’s El Niño was the record level of wind shear across much of the Caribbean Sea. Strong upward motion in the tropical Pacific resulted in strong wind between about 5,000 feet and 40,000 feet across the western Caribbean and extending as far east as the Lesser Antilles at times. This is what caused would-be hurricanes such as Erika to weaken and ultimately dissipate. Only a narrow band of favorable conditions existed in the deep tropics where we saw hurricanes Danny and Fred form, far away from land areas.

Outside of the extreme upper level winds, in the southwest Atlantic, there was another area of favorable conditions and the resulting hurricanes Joaquin and Kate owe their existence to that fact. Otherwise, El Niño really did help kill off the Atlantic season as far as direct impact on the United States was concerned.

2016 might not have that protection and in fact, there is a good chance of that happening, according to the latest projections from a suite of computer models.

CPC/IRI Consensus Probabilistic ENSO Forecast

CPC/IRI Consensus Probabilistic ENSO Forecast

As of the December 10th update from the CPC/IRI (Climate Prediction Center/International Research Institute), the probability of El Niño conditions holding on through March 2016 are near 100%. After that time, things change quickly.

Once we get to spring, El Niño begins to fade as cooler water moves in from the subsurface and stronger trade winds resume across the tropical Pacific. This is reflected in the projections with the probability of El Niño conditions dropping to 60% by late spring.

Moving further out in time, the various models suggest only a 20% probability of El Niño holding on by mid to late summer 2016. This has huge implications on the Atlantic hurricane season since the absence of El Niño by itself is typically a positive signal for Atlantic tropical cyclone activity.

As we know all too well, there are many other factors at play and the Atlantic Basin seems to have the most year to year variability and is subject to large errors in forecasts for seasonal activity – 2013 being a prime example. There was no El Niño that year and it appeared that conditions would be favorable for one of the busiest seasons since 2005. Other unforeseen factors set in by summer and the season was one of the most tranquil in recent memory.

SST anomaly forecast going out to July 2016. Notice the blue showing up in the tropical Pacific - that is the beginning of La Nina conditions there

SST anomaly forecast going out to July 2016. Notice the blue showing up in the tropical Pacific – that is the beginning of La Nina conditions there

While the El Niño fades, another interesting phenomenon may begin to take shape. Some of the climate models are developing a very warm tropical Atlantic next year. If this comes to pass, especially if the far northern Atlantic is cool compared to average, then it would signal yet another reason to believe that changes are ahead for Atlantic activity next season.

Much of this was reflected in Dr. Phil Klotzbach’s first outlook for the 2016 hurricane season which was released last week. The December discussion indicates a 25% chance of seeing a hyper-active season in 2016 which would be a significant change in what we’ve seen in recent years. A lot will depend on exactly how much the El Niño weakens and how warm the tropical Atlantic manages to get before August-September-October rolls around.

Trying to put this all in to perspective, it is kind of like having a the #1 recruiting class in college basketball. Your team is loaded with incoming talent, maybe a couple of seniors with terrific skills to round things out. It appears that the next basketball season is going to be spectacular for your team. They might even have a chance to win it all and be National Champions. Along the way, things can happen: a torn ACL for your star forward. Coach gets sick during tournament play. Another player goes down with a broken hand. All of a sudden, your #1 team is now losing game after game and what looked like a sure-thing season turns out to be anything but. You just never know.

Hurricane season is much the same. It really is. There can be a plethora of signals for the Atlantic Basin to be very active and yet, when all is said and done, it wasn’t and no one really knows why until after the fact. Right now we are in the equivalent of the signing period of college basketball – when the top recruits begin to choose their college. We won’t know how things pan out until much later – maybe even during the season itself. Yet, much like college ball, I see potential building for a busy 2016 in the Atlantic. However, just because something might happen, doesn’t mean that it has to happen.

I’ll post an update to this blog in mid-January. By then, we will have even more data from the various climate models and the picture of what lies ahead will become just a little bit clearer.

M. Sudduth 10:15 AM ET Dec 14

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Tropics finally quiet for a while

After a fairly busy period from about August 20 until most recently with Joaquin, it looks like things are finally going to calm down and remain that way for the time being.

Typically, we focus our attention on the western Atlantic, Caribbean and Gulf of Mexico this time of year. The so-called “Cape Verde” season is essentially over as the west African monsoon shifts south again and the strength of the tropical waves diminishes.

Upper ocean heat content remains quite high across much of the western Atlantic and Caribbean Sea.

Upper ocean heat content remains quite high across much of the western Atlantic and Caribbean Sea.

Water temps are also coming down beginning with the near-shore first. With longer nights and less incoming solar energy due to the seasonal change of the sun angle, there is simply less heat being added to the surface of the ocean in the Northern Hemisphere. However, ocean heat content is still very high in many places including the western and northern Caribbean Sea. It is this region that we watch closely during October for the possibility of intense hurricanes developing although we have not seen anything of that scope in almost three years – Sandy was the last.

The outlook for the next week to ten days suggests that the tropics will remain quiet. Global models were hinting at development starting later this week but they have all but completely backed off of that idea in recent days. Overall, I think that we will easily reach the ten year mark of the last hurricane to make landfall in Florida which also was, coincidentally, the last category three hurricane to hit the United States: Wilma. The date is October 24 and unless something develops between now and then, we will cross the ten-year mark and will likely go well in to the 2016 Atlantic hurricane season before there is a chance that the streak will end.

As of now, the 2015 season has over-achieved. We predictions were for a “quiet” season and it has been anything but. Yes, it’s true that no hurricanes have made landfall along U.S. shores but the impacts to our neighbors, the two close calls with Erika and Joaquin and the indirect impact of the Southeast flood event due to Joaquin’s moisture contribution have all made for a busy several weeks. In fact, the ACE score which measures the energy output from tropical cyclones is much higher than most had predicted. Right now it stands at 56 which is just 9 points lower than the total for last year. While I think the next week to ten days will be fairly quiet, it is entirely possible that we will have one or two more hurricanes develop somewhere in the Atlantic between now and the end of November. As such, I expect the ACE score to eclipse the 65 from 2014. We shall see.

M. Sudduth 9:25 AM ET Oct 12

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Joaquin terrible for central Bahamas, likely misses U.S. coast as separate major storm system unfolds

Weather map showing the complex set up along parts of the East and Southeast

Weather map showing the complex set up along parts of the East and Southeast

For parts of the central Bahamas, Joaquin will go down in history as being one of the worst hurricanes in memory. I cannot even begin to imagine what it must be like for the people in the region – enduring more than 24 hours of major hurricane activity, pounding the region relentlessly.

The only sliver of good news for that area is that the hurricane is finally beginning to move northwest but it is at quite a slow pace. This will prolong the conditions that include hurricane force winds, torrential rain and storm surge. Eventually, Joaquin will clear the region but not before leaving a devastating mark on several islands of the central Bahamas.

At this point, the forecast calls for no landfall along the U.S. coastline. The ECMWF idea of an out-to-sea track was apparently right all along. In this complex pattern, it is in fact very impressive that the model caught on early and held on to the run-to-run consistent turn away from the United States.

While it’s never over until it’s over, the confidence in the forecast track has increased considerably over the past 24 hours. There is still a chance that New England or the Canadian Maritimes could be impacted but even there, the risk is low. It’s also possible for Bermuda to be in the path of the hurricane but again, it’s too soon to know for sure, especially in this strange set up.

We won’t ignore Joaquin but another, completely separate, weather event is unfolding across a good deal of the Southeast and Mid-Atlantic states.

Basically we have a stalled frontal boundary over the coastal waters that is the focusing point for extremely heavy rain moving in from the warm waters of the Atlantic. Add to the mix a potent upper level low, which was initially thought to be likely to capture Joaquin and bring it in to the region, and the set up is there for catastrophic flooding in some areas.

Before getting in to the potential for how bad this could be, note that all along the Southeast and Mid-Atlantic region there will be an increase in strong winds, especially from the Delmarva and in to southern to central New Jersey. The strong high pressure over Canada combined with the low pressure associated with the stalled front will increase the pressure gradient or a tightening of the winds across the coastal waters. Some locations along the New Jersey coast may see winds gust over 55 mph. Additionally, higher than normal tides, large waves bashing the immediate coast and possible heavy rain will make this weekend quite miserable.

However, it appears that the rain will have the most impact from this weather system. After reading some of the forecast discussions from area NWS offices, it seems apparent now that the chance for “life threatening flooding” could occur in some areas, especially in South Carolina and more specifically, in and around Charleston.

The culprit is NOT Joaquin – probably not even indirectly. Instead, it’s the powerful dynamics of the upper level system dropping across the region. This will tap in to the abundant moisture plume coming up from the southwest Atlantic to drop incredible amounts of rain. It is not out of the question that isolated areas will see more than 15 inches of rain when all is said and done. This is obviously too much too soon and will certainly create dangerous conditions. The problem is, there is no way to know exactly what geographic locations will be impacted the most. It seems likely that widespread flooding is possible with a concentration on parts of South Carolina from the midlands to the coast. Needless to say, slow down while driving, keep kids out of flood waters and completely avoid flooded roads even if you “know the area” or have an SUV/truck. Common sense must prevail or people will die, it’s that simple.

The storm system will last through the weekend and gradually come to an end by Monday. Joaquin should stay well out to sea by that point and the region can begin to dry out. Between now and then, there is chance for historic flooding but the issue is not knowing precisely where this could take place. Your best bet if you live in or are traveling through the Carolinas is to be aware of possible rapidly changing conditions.

I will be working with my colleague from Houston to cover this event in North and South Carolina. We will have live video starting early this afternoon as we work to figure out where to set up some of the equipment we would normally use during a hurricane. Wind is not our main concern though I probably will set up our weather station along the Outer Banks today, along with a live camera feed from Kitty Hawk along the beach road.

From there, we will more than likely go to Charleston and vicinity and set out more unmanned cameras normally used for storm surge flooding. These new generation cams last for around 36 hours each and have audio. It will be quite something to hear the excessive rain hitting the boxes as we watch the water rise.

All of our live video will be available via a special page I have set up on the site. I will post a link to it later today once we get rolling. The video will be on Ustream and free to access and share.

It is worth saying that even though hurricanes are vastly interesting to me, I have to admit that Joaquin likely missing the U.S. coast is going to go down as being one of the best case scenarios we’ve seen in recent memory. It is hard to fathom how bad things would be across the region if we added a category one or two hurricane with its massive arsenal of effects on top of the current epic weather event unfolding. Luck was on our side this time…

I’ll have more later including a brief video update before we head out.

M. Sudduth 8:30 AM ET Oct 2

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Joaquin forecast tricky, Ida coming back from the hurricane graveyard

Overnight model plot showing the fairly large spread in track possibilities for Joaquin

Overnight model plot showing the fairly large spread in track possibilities for Joaquin

This is going to be one of those times when nothing comes easy. If we are going to have hurricanes, might as well have them easy to forecast and sometimes, even when they are intense like Katrina, they are. Others, not so much. The case with Joaquin looks to be a real pain in the neck. Before getting to the forecast part, let’s take a look at what we know.

As of this morning, Joaquin was a 40 mph tropical storm battling relentless northerly shear. Remember, upper level winds are not favorable when the pass over a developing or established tropical cyclone. The best environment is one that features outflow channels and light winds at the upper levels, to allow very deep thunderstorms to tower high in to the atmosphere. Right now, this is not what is happening with Joaquin and unless the shear abates, the storm will struggle.

Water temps along the track of the storm are plenty warm with ample undisturbed upper ocean heat content. While it is not nearly as high-octane as the NW Caribbean, the western Atlantic has plenty of energy for a hurricane to develop from and feed off of. The question is, will Joaquin thrive or starve at the head of the buffet?

It really will come down to how much the shear relaxes, if at all, in the coming days. Some of the intensity models show significant strengthening, as does the global model ECMWF. Keep in mind, some models are developed specifically for tropical cyclones where as the global models predict weather on a global scale and the tropical cyclone is part of the overall big picture. Right now, the NHC is admittedly being conservative with the intensity forecast – holding below hurricane strength.

Now for the track forecast. This is obviously what everyone wants to know about. As I said in my opening paragraph, we wish it was always easy but it’s not and so we deal with it.

I want to point out that the NHC makes mention of the fact that their confidence in the track forecast is “extremely low” right now. I think this is incredibly honest and shows the human side of this tedious work. Model guidance is helpful but is spread out right now, or divergent, and thus the forecast of where Joaquin will track is very tough to call. Here’s why.

First, intensity will likely dictate track to some extent. A stronger, deeper hurricane situated in the atmosphere might, just might, be enough to get swept out to sea by an approaching trough of low pressure moving in to the Southeast later this week. On the other hand, no matter what the intensity of Joaquin is, it may get caught by the trough if it tries to cut itself off from the main flow- what we call a cutoff low. This could swing Joaquin northwest with time and bring it in to the Mid-Atlantic states later this weekend. Many of the model solutions show this happening to some extent. Of course, others do not. This is why the track forecast is so tough to call right now. What’s more frustrating is that we are not talking about a week to 10 days out like we see with large hurricanes coming in from the eastern Atlantic. Joaquin is literally in the backyard, waiting to make its move. You would think, and hope, that with it being so close to land already (relatively speaking of course) that the forecast would be easier. It’s just not and that’s the reality of the situation.

One thing we can count on is data. NOAA will have plenty of additional data to input in to the global models as soon as the G-IV missions begin for Joaquin. The high-altitude jet will drop numerous devices that will sample the atmosphere and give the models more data from the steering layer to work with. This should help to refine things in the days to come.

So what should you be doing now if you live along the coast from say, North Carolina to Maine? Just keep monitoring what’s going on and be ready to act if it looks like Joaquin will in fact head your way. Remember, even if it transitions from a hurricane ( assuming it becomes one) to a post-tropical storm or other less commonly used term, there will likely be a lot of rain, wind and more coastal issues. The beaches from parts of eastern Florida up the East Coast are not in their best shape right now due to recent nuisance storms and persistent onshore flow. Joaquin need not be a substantial hurricane to cause substantial problems for people and property. Do not lose sight of the fact that a storm of any magnitude can impact you. Needless to say, it will be a very interesting next few days.

As if Joaquin weren’t enough, we have to watch for the remnant energy from Ida to try and stage a comeback. The NHC gives it a 40% chance of doing so and there is a chance that this system too gets involved with the pattern near the East Coast in the coming days. The result is likely to be a tremendous amount of rain and serious beach erosion from the North Carolina Outer Banks to New England.

I will post a full-featured video update this afternoon highlighting the very latest on Joaquin and what the chances are of Ida making a comeback. Stay tuned, it looks like October is going to start off very stormy – how much so and what impact it all has remains to be seen.

M. Sudduth 8:40 AM ET Sept 29

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