Quiet time short-lived? Some model support for Gulf development

Substantial MJO pulse forecast by the ECMWF over the next two weeks

Substantial MJO pulse forecast by the ECMWF over the next two weeks

The rest of this week is likely to remain nice and quiet across the Atlantic, Caribbean and Gulf but once we get to next week, things could change. Here’s why…

First of all, the time of year supports Gulf of Mexico or western Caribbean development. We shift away from the Cape Verde region and the waters between there and the Lesser Antilles towards a pattern that favors development much closer to land areas. We might be seeing that come to fruition in the coming days.

The other reason I think development could happen is the progression of a strong MJO or Madden-Julian Oscillation pulse. Think of it as a period of fertility in the tropics. Instead of dry, sinking air, the MJO typically brings with it an increase in convection and a general rising motion in the atmosphere. These things are needed to even have a chance for a tropical storm or hurricane to develop.

According to the GFS and the ECWMF, the MJO is about to amplify significantly in to the phases that would, in theory, support development either in the southeast Pacific or the western Caribbean/Gulf of Mexico regions.  Water temps are plenty warm and so now it’s just a matter of watching to see what happens. So far, both the GFS and the ECMWF show signs of developing a tropical storm in the 8 to 10 day time frame. For what it’s worth, the two models are in remarkable agreement on the timing and the general placement of such development – the southern Gulf of Mexico. I usually don’t pay much attention to model forecasts beyond the 5 to 7 day time frame but when the two (rival) models are in agreement, it is worth watching a little closer.

Right now, nothing to worry about at all. It’s important to remember that we are still very much in hurricane season and it’s not over until it’s over. There are signs beginning to come in to focus that we might have one more system to deal with before all is said and done. Obviously I will keep a close eye on how things shake out over the next week or so.

I’ll have more here on this tomorrow.

M. Sudduth 8:35 AM ET Oct 14

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

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

The makings of an epic forecast bust

Sometimes the forecast just doesn’t work out. In this case, if Joaquin does not hit the United States, people better realize how lucky they really will be in light of the incredible flood event that is likely unfolding despite the hurricane.

I produced a video discussion outlining what a wild ride it’s been so far this week. Yes, it all began just 96 hours ago and it’s not over yet.