Maria may be weakening but don’t let that fool you – the energy put in to the ocean will be significant for the Outer Banks

8:40 AM ET Monday, September 25

Maria is on a weakening trend but the energy that has been put in to the ocean is headed for the shore. As such, the impacts along the Outer Banks of NC could be significant in some locations. Maria will be a lesson in understanding impacts and the bigger picture rather than focusing on category and whether or not it makes landfall.

Here is my morning video discussion:

No major track changes with Maria from the overnight model runs

8:50 AM ET Friday, September 22

So far, no major changes in the overall track and future progress of the hurricane as it moves past the Turks and Caicos today – eventually turning more north with time.

In general there is a subtle shift more to the north with the track guidance rather than west although the ECMWF is perhaps a little more west than we saw 24 hours ago. The outcome seems to be the same, however, and that is the fact that Maria should turn away from the East Coast of the U.S. with time.

After Maria clears the pattern, we will begin to shift our focus to the western Caribbean where most of the long range guidance suggests a lowering of pressures and the potential for development over the coming weeks. October is notorious for powerful hurricanes originating from the western Caribbean and it will not surprise me at all to see this happen this season.

Here is the first of two video posts coming for today:

M. Sudduth


Maria likely to turn out before directly impacting USA…but….

9 AM ET Thu Sept 21

Satellite photo of the western Atlantic with Jose to the north and Maria to the south

Satellite photo of the western Atlantic with Jose to the north and Maria to the south

After a devastating, crushing landfall across Puerto Rico this time yesterday, Maria is now out over the warm waters of the southwest Atlantic. The eye has become quite large with hurricane force winds now extending out from the center some 60 miles. Maria has regained category three intensity and I think it will get stronger still once it moves farther away from the island of Hispaniola.

As the people of Dominica, St. Croix and Puerto Rico labor to begin the process of rebuilding their lives and their communities, there remains one more chapter to the Maria story still unwritten. I say unwritten, though the outline sure seems to be solid at this point: Maria never makes it to the USA coastline.

All of the available track guidance suggests, at least at first glance, that Maria will turn a graceful curving path away from the Southeast coast over the next five to seven days. The closest it is likely to get to land again will be today and tomorrow as it approaches the Turks and Caicos islands – but remaining just east in terms of the dangerous core of the hurricane.

After this time period, it seems almost certain that the lack of strong high pressure over the western Atlantic, due mainly to the presence of Jose, will allow Maria to eventually lose its western progress and begin turning back towards the east and eventually on out in to the open waters of the Atlantic.

Sounds like all is well for the East Coast…except for one thing: it hasn’t happened yet.

Now I know this sounds obvious but a forecastĀ is subject to error; whether by humans who lay out projections on a map for the center position of a tropical cyclone or by computers which use numerical prediction to guide the humans. If it hasn’t happened yet then it is only a forecast and remains under the limitations of modern weather prediction – even if it looks like a lock.

Let’s look at it from a different perspective. Instead of “why is Maria turning out to sea?”, let’s approach it from “what would it take for Maria to turn back towards the coast?”

Here is my answer: If we see more ridge (high pressure) developing north and east of Maria then it will not fade east and has a chance to continue to gain longitude (westward progress). Right now, something very important is occupying the space that would normally be filled with a dome of air and that is a tropical storm named Jose.

As a hurricane, Jose literally moved up in to and split the ridge, causing an alley-way or weakness for Maria to follow. As long as this alley stays open, Maria will turn out. This is quite likely what will happen. However, if Jose turns back west and comes inland over the Northeast or Mid-Atlantic states then what does that tell us? Why would Jose turn back to the west? Blocking high pressure. That’s why. The atmosphere is forecast to build what we call “heights” over the coming days in a fashion that would normally steer something like Maria in to the Southeast coast. But, with Jose having cut the ridge out enough, Maria is probably going to gain more northward progress with a turn out to the east with time.

Probably. Not certainly.

What we need to look for is how far west Maria tracks over the next 48-72 hours. We also need to watch what Jose does. I believe from what I have read and seen in the model guidance, that if Jose turns west and even south of west, and is driven in to the coast of say, New Jersey (however weak Jose may be it is still something to watch for), then Maria could pinwheel in as well as the models seemed to suggest yesterday. It’s a long shot but there are several members of the 51 runs of the ECMWF model that show this scenario. I cannot display that model output here as it is licensed for use by commercial weather companies. This is the advantage of having an ensemble prediction system – it allows the “what if” cards to be played. In the case of Maria, we are not yet seeing all 51 members of the ECMWF model depict an “out to sea” path.

To be fair, the 21 members of the GFS ensemble group do show 100% “out to sea” as far as USA impacts go. Which model will be correct? Wish I knew.

So the bottom line here is that while the odds favor the East Coast of the USA having to never deal with Maria directly, those odds are not 100% just yet. We’re getting close but close is not the same as there.

I’ll post a video discussion this afternoon after the 12z GFS and ECMWF models complete their runs and we’ll see if the odds have changed any.

M. Sudduth

When we talk about category five, what exactly does that mean?

Maria became the 2nd category five hurricane of the 2017 season, following in the footsteps of historic hurricane Irma whose winds peaked at an astonishing 185 mph.

What exactly does category five mean? For most, it is the absolute benchmark of fear and anxiety when it comes to hurricanes. When you hear category five, you always pay attention – no matter where you live – hurricane zone or not.

The categories assigned to hurricane intensities are for wind and the potential damage that can be caused by that wind. It’s not pressure, not surge, not rain and not size. It’s all about the wind and its damage potential. A category five hurricane is capable of inflicting catastrophic damage – no doubt about it.

However, we must look at the bigger picture to understand the whole of the hurricane – not just its category. We are so fixated on the category yet most people do not understand the rest of the inner workings of the cyclone.

First of all, the hurricane force winds only extend out from the center of Maria up to 30 miles. This is the good news. The bad news is that somewhere within this wind field are extreme winds reaching 160 mph with higher gusts. The recon plane and the instruments used to measure wind and pressure cannot be everyone all at once – the convection changes, thunderstorms go up, then they go down; it is very dynamic inside the core of an intense hurricane. Luckily for us mere humans, the radius of maximum winds, in the case of Maria, is fairly small. This means that it will take a direct hit of the core to bring those unimaginable winds to any specific location. Obviously, this happened with Irma and again last night with Maria in the case of the island of Dominica.

The other aspect that gets lost when thinking of hurricanes solely by their category is the immense threat from rain and the resulting floods. If ever there was a lesson in this in recent times it was Harvey in Texas.

Harvey was an exceptional situation where by the storm slowed down and virtually stalled over the region – this led to the historic rain fall totals that exceeded 4 feet in many locations.

As for Maria, the slow movement is a problem but its the island of Puerto Rico itself that poses the biggest issue in terms of rain. Puerto Rico has mountains and those mountains are lined with beautiful tropical river systems that run through valleys and eventually reach the sea. What do you think is going to happen when 10, 15 or 25 inches of rain falls on those mountains in short order? Is there a category for that? No. If there was, it would also be a five in my opinion. The flood threat from Maria for the people, places and things in Puerto Rico is exceptional and I am very concerned about it. The wind will grab the headlines but the rain could be what Maria is ultimately remembered for. We shall see.

RAINFALL: Maria is expected to produce the following rain
accumulations through Thursday:

Central and southern Leeward Islands...10 to 15 inches, isolated 20
U.S. and British Virgin Islands...10 to 15 inches, isolated 20
Puerto Rico...12 to 18 inches, isolated 25 inches.
Northern Leeward Islands from Barbuda to Anguilla...4 to 8 inches,
isolated 10 inches.
Windward Islands and Barbados...2 to 4 inches, isolated 6 inches.
Eastern Dominican Republic...4 to 8 inches, isolated 12 inches.

I have prepared a video discussion this morning emphasizing the point about the small hurricane force wind area within Maria’s core. I will have another video update posted this afternoon after the 5pm NHC advisory package is released.

M. Sudduth