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
inches.
U.S. and British Virgin Islands...10 to 15 inches, isolated 20
inches.
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

 

 

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Maria now a hurricane and poses a significant threat for catastrophe for Puerto Rico and other islands of the NE Caribbean

12:15 AM ET Monday, September 18, 2018

Sometimes a video is truly needed to express the gravity of a situation. Right now, we are looking at the potential for a terrible disaster to unfold for portions of the islands of the NE Caribbean Sea as hurricane Maria gains strength. If there was ever a time when people need to take something seriously – this is it.

Also, Jose is not nearly the threat that Maria is but the hurricane will bring tropical storm conditions and an array of coastal impacts to a good deal of real estate up and down the East Coast. I take a look at the latest from my hotel in Kitty Hawk, NC in this late night video update:

M. Sudduth

 

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Recon crew finds 99L not organized enough to be TD or TS yet

Visible satellite image showing a fairly disorganized tropical wave moving through the NE Caribbean Sea

Visible satellite image showing a fairly disorganized tropical wave moving through the NE Caribbean Sea

The value of the Hurricane Hunters is priceless. Their work and dedication is without equal in the weather world. Today, they proved it again with the flight in to invest area 99L. The data indicates that while the overall structure of the tropical wave has improved some, it’s not quite enough to name it a depression or a tropical storm.

Instead, we have a broad area of lower air pressure and plenty of general turning in the cloud motion. However, there is some fairly strong wind blowing over the top of the system and this is injecting dry mid-level air while also pushing any deep thunderstorms away from the weak low level center.

We can see this in the satellite image I have included here. Notice that the clouds are not symmetric in appearance but rather pushed off to the south and southeast. While there is clearly a weak circulation nearing Puerto Rico, it has yet to completely close off and become well defined. It may take another day before that happens which is generally what the models that develop this system indicate.

So for now, we still have a tropical wave but it is bringing with it strong winds and periods of heavy rain for portions of the islands of the NE Caribbean Sea. This will continue to spread WNW towards the Turks and Caicos and eventually the southeast Bahamas.

For what it’s worth, the latest GFS model run indicates once again that 99L will remain a weak system and never really impacts Florida. I do not understand why this is the solution the model is coming up with but it cannot be dismissed completely. We just don’t know – despite the insistence of the very reliable ECMWF or Euro model that this will become a hurricane and enter the Gulf of Mexico. Once I get a look at the latest output from this morning’s ECMWF run, I will post an update here, followed by a thorough discussion in my afternoon video blog. If you have our app, Hurricane Impact, be sure to check the video section later today for that update.

M. Sudduth 1pm ET Aug 24

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Gonzalo likely to become a hurricane within next 24 hours as it passes through NE Caribbean

Track forecast for Gonzalo showing it passing east of Puerto Rico tonight

Track forecast for Gonzalo showing it passing east of Puerto Rico tonight

The overnight model runs and latest forecast track from the National Hurricane Center dictate that I not go to Puerto Rico today for Gonzalo. This does not mean I think the island will have zero impact but I don’t believe it will be significant enough to warrant me traveling there. Sometimes the weather makes the call and this is one of those cases I do believe.

So far, Gonzalo is managing to steadily increase in strength. Winds are now 60 mph with a falling pressure. The storm is quite small in size compared to something like Irene which passed through this region three years ago in August. This should serve to keep the strongest winds confined to a rather small radius around the storm. It also means that, if an inner core can become established, Gonzalo has a chance to increase in intensity quickly.

For the Caribbean islands today and tonight, it’s all a matter of where the bands of convection set up, rotate through and how that impacts the various islands in the path of the storm. Computer models cannot possibly resolve this to any degree of accuracy and thus local radar is the best tool for watching in real time.

Right now, the movement is steady at around 12 mph. The heading is 280 degrees which would bring the storm through the northeast Caribbean, probably passing 60 miles or more to the east of Puerto Rico but directly over the U.S. and British Virgin Islands. Almost all of the computer model guidance suggests this path as being quite likely over the next 18 to 24 hours. This would keep Puerto Rico on the west side of the small circulation and unless a more westward motion ensues, I see little wind impact for the island. Rain, on the other hand, could be problematic as and bands that move through could drop a quick inch or more, adding up to over 4 inches in places, especially at higher elevations.

Obviously, boating interests throughout the region need to simply stay in port until the storm passes by later tonight. Winds and seas will be highest between now and the next 24 hours or so with much better conditions setting up for mid-week and beyond.

Once Gonzalo gets out of the Caribbean and in to the Atlantic, the set up is quite ripe for substantial strengthening. Model data suggests that Gonzalo could reach near category three intensity over the very warm water of the Atlantic. This will send swells back towards the northern Caribbean islands as well as the Bahamas and parts of the Southeast coast later this week. Surfers will love this but swimmers should be on the lookout for potential dangerous surf conditions. I will address this more in tomorrow’s post.

The track forecast after the Caribbean is extremely important for one small area: Bermuda. The odds of the center passing directly over Bermuda are quite small yet Fay did it just the other night. It is possible that Bermuda will have to deal with a direct impact from Gonzalo but it’s too soon to know for sure right now. We’re talking about 5 days out, maybe less. Needless to say, interests in Bermuda should be watching Gonzalo very closely over the next couple of days.

This is where I will be focusing my attention now as well. If it looks like a close enough pass of Gonzalo will take place in Bermuda, then I will head out there as soon as Thursday to be ready. It’s a tough, tough call since the island is quite expensive to travel to on many levels. Yet, an October hurricane hit from the southwest is something that rarely happens there, so the chance to gather data and document the event with video is something I don’t take lightly. I think that even passing within 50 miles of Bermuda would bring hurricane conditions and so it is something I will be monitoring quite closely today and tomorrow.

Elsewhere in the Atlantic, Fay is moving quickly across the northern reaches and will soon transition in to a more typical large ocean storm than a concentrated tropical cyclone. Only shipping interests will be concerned with its progress.

In the Pacific, a low pressure area, labeled as invest 95C (for Central Pacific) is likely to become a tropical storm and eventually a hurricane to the east-southeast of Hawaii. As rare as it is, there is at least a chance that it will move in that direction over the next several days. For now, it’s just something for folks in Hawaii to monitor but after a quite tumultuous season in the Pacific, it would not surprise me in the least to see one more impact for the String of Pearls. I’ll talk more about this in tomorrow’s update as well.

The MJO or Madden-Julian Oscillation is likely to be quite favorable for development over the next couple of weeks

The MJO or Madden-Julian Oscillation is likely to be quite favorable for development over the next couple of weeks

Things are quite busy for mid-October and we’re likely not done yet. Long range guidance suggests that the Gulf of Mexico or western Caribbean Sea could become more active as we move through the next week to 10 days. It is part of a quite favorable period called the Madden-Julian Oscillation moving through the Western Hemisphere over the next couple of weeks. This means that the overall upward motion of the atmosphere is enhanced and allows for more tropical convection to flourish. There will be quite a bit to keep track of I believe before the month is over. For now, we’ll see what Gonzalo does but do not be shocked if we’re talking about a potential storm brewing somewhere in the western Caribbean of southern Gulf of Mexico next week.

I will have another update on Gonzalo here tonight and a full run down of the tropics tomorrow morning.

M. Sudduth 8:47 AM ET Oct 13

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Tropics going to be news maker this week

It seems more like mid-September than approaching mid-October in terms of activity in the Atlantic Basin. We have a hurricane, Fay, and newly designated TS Gonazlo, forecast to become a hurricane and move through portions of the northeast Caribbean Sea. It is going to be a busy week ahead.

First up, Fay. After lashing Bermuda with 80+ mph winds last night, the storm strengthened in to a hurricane and is now moving quickly out in to the north Atlantic. There’s not much else to say about Fay except that it just goes to show that intensity and track forecasts are not exact sciences. No one thought that Fay would bring hurricane conditions to Bermuda several days ago when it was a mere “subtropical storm”. Fay will track out in to the open Atlantic and only be an issue for shipping interests.

Now we turn our attention to Gonzalo. The NHC upgraded 90L to tropical storm Gonzalo this afternoon. The forecast is aggressive and makes the storm a hurricane as it passes by Puerto Rico on Tuesday. As noted in the 5pm NHC discussion, there is a chance that Gonzalo undergoes rapid intensification if it develops a well defined eye. If this happens before cross in to the Caribbean, then numerous islands in the path will have to deal with a potentially powerful hurricane.

Right now, the forecast calls for strengthening and a track that would cut across the northeast Caribbean, passing very close or over eastern Puerto Rico. This would put the U.S. and British Virgin Islands right in the middle of the core of the potential hurricane – not a good place to be obviously!

The next 24 hours will be extremely important as Gonzalo fights off dry air that occasionally tries to disrupt the intensification process. Water temps are very warm and only the dry air is an inhibiting factor right now. Interests across the northeast Caribbean need to be making preparations for a strengthening hurricane. Remember too this is not just about wind but also rain. The mountainous terrain of Puerto Rico is susceptible to flash flooding and mudslides as Gonzalo passes by.

With all of this going on, I am preparing to head to Puerto Rico tomorrow morning. I will be working with The Weather Channel to provide (hopefully) exceptional live video and weather data from the area. This is my first time leaving the Lower 48 to intercept a hurricane. I arrive mid-afternoon and will have to quickly get things set up and running. Along the way, I will post video blogs and updates via our app, Hurricane Impact, and through Instagram (follow @hurricanetrack). The weather data will stream to the app and update every minute with wind, pressure and a live image from the station’s location in Puerto Rico. A lot will depend on the exact track and intensity of Gonzalo but odds are that hurricane conditions will be felt in parts of Puerto Rico and surrounding areas. It is going to be an interesting mission to say the least. I am ready and look forward to capturing what ever Gonzalo dishes out.

I will do my best to update the blog throughout the next few days. I am going to ask colleague Mike Watkins to fill in while I am out, so look for posts from him starting tomorrow.

I leave North Carolina at 7:30 AM – I’ll have more from Puerto Rico tomorrow afternoon.

M. Sudduth 8:45 PM ET Oct 12

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