Tropics getting very busy as we close out August

There is a lot going on, no doubt about that. It’s the end of August and the hurricane season is kicking in to high gear. Let’s start in the Pacific actually then move east from there…

TS Madeline/Hurricane Lester

TS Madeline is forecast to strengthen in to a hurricane as it tracks generally towards Hawaii in the coming days. It should weaken upon approach and perhaps turn more south with time.

TS Madeline is forecast to strengthen in to a hurricane as it tracks generally towards Hawaii in the coming days. It should weaken upon approach and perhaps turn more south with time.

We have a pair of tropical cyclones to watch closely in the east and central Pacific over the coming days. First up is tropical storm Madeline which is currently situated well to the east-southeast of Hawaii. The forecast calls for the storm to reach hurricane intensity as heads generally westward early next week. While the track suggests a threat to Hawaii, it seems as though less favorable conditions will set in and Madeline will weaken and probably push more south with time, avoiding a direct impact to the islands. However, as we know, this can change so it’s obviously a good idea to keep tabs on the progress of this storm.

Much farther to the east over the eastern Pacific we have hurricane Lester with 100 mph winds. It too is tracking almost due west and could reach the vicinity of Hawaii in about a week. It is something to monitor but remember, it is very difficult for hurricanes to make landfall in Hawaii from the east. We usually see hurricane threats from the south as they turn from lower latitudes and track northward across the region, such as Iniki did back in 1992. While Lester is a strong hurricane, I would not worry too much about it right now – plenty of time to watch.

99L

Morning track plots showing the spread of the various computer models. Most of the more reliable models suggest a landfall, if it were to develop, somewhere along NE Gulf of Mexico coast.

Morning track plots showing the spread of the various computer models. Most of the more reliable models suggest a landfall, if it were to develop, somewhere along NE Gulf of Mexico coast.

Next we have good ole 99L. Seems like it has been with us forever. The area of interest that just can’t seem to develop. So far, it still hasn’t and doesn’t look like it will anytime soon. Upper level winds continue to plague the would-be storm, pushing any deep thunderstorms that try to develop away from the low level center which is currently moving through the Florida straits and Keys area.

It has been a frustrating week tracking 99L with all of the computer model flip-flopping that we’ve had to deal with. About the only one that has been consistent with intensity is the hurricane specific HWRF model which goes bonkers with development on almost every run. So far, none of that has come to pass. The GFS has done fairly well indicating little development thus far and not much more to speak of in the days ahead. The Euro or ECMWF on the other hand has gone back to suggesting a hurricane threat for Florida and possibly the Southeast coast once the system moves back out over the Atlantic.

My feeling is that so far the system has under-performed and until the shear relaxes and we see deep convection wrapping around the low level center and maintaining for 24 hours or more, it won’t pose much of a threat as far as being a strong hurricane. That being said, it is possible that 99L could reach hurricane intensity somewhere in the Gulf of Mexico next week. Water temps are very warm and all it takes is a period of favorable upper level winds for the lid to come off.

I believe the next 24-48 hours is the key here. If we see it develop by Tuesday then folks in Florida could be in for some significant impacts from this system. Unfortunately we will just have to wait and see how things pan out. For now, it remains only a strong tropical wave of low pressure, nothing more.

91L

Invest area 91L with some deep thunderstorm activity near the center. It is moving towards the NC coast but should turn north and back out to sea before reaching Cape Hatteras and vicinity.

Invest area 91L with some deep thunderstorm activity near the center. It is moving towards the NC coast but should turn north and back out to sea before reaching Cape Hatteras and vicinity. (click to view animation)

Next we have invest area 91L between Bermuda and Cape Hatteras and moving westward with a turn more to the west-northwest expected soon.

Right now, strong upper level winds coming from the east are keeping the convection that has managed to develop just west of the well defined low level center. You can clearly see this on the satellite image I have posted here. In fact, this looks to me like it would be classified as a tropical depression but without recon in there to verify right now, it’s not officially anything but an area of interest. We should know later today once the recon crew gets in there – perhaps this becomes TS Hermine? We shall see.

The models are in pretty good agreement that this will turn more to the north and then curve back out over the Atlantic over the next couple of days. The key to any appreciable impacts to the North Carolina coast will be how close the system tracks before doing so. Most of the guidance keeps it just east of Cape Hatteras and vicinity but close enough to warrant concern, especially for off-shore boating interests.

I’ll keep a close eye on this one since recon is planning to investigate later today. Once we get their reports we will know if this has in fact become a next named storm or at least a tropical depression.

Hurricane Gaston

Hurricane Gaston track forecast showing it staying out over the open Atlantic.

Hurricane Gaston track forecast showing it staying out over the open Atlantic.

Gaston has become the strongest hurricane in the Atlantic Basin for 2016. Top winds are near 90 mph and are forecast to go up from there. The hurricane has developed an eye and is moving away from all of the hostile conditions that were hindering significant development over the past day or so.

The NHC is forecasting Gaston to reach peak intensity of 110 mph before reaching cooler water later this week. I won’t be at all surprised to see the hurricane reach 120 mph or more over the warm water of the sub-tropics. This seems to be the norm in recent years – hurricanes reaching peak intensity well outside of the deep tropics. Fortunately for land areas, Gaston will only be tracking over open ocean.

Future 92L in the far eastern Atlantic

Large tropical wave over Africa that will almost certainly be a named storm in the far eastern Atlantic in the coming days.

Large tropical wave over Africa that will almost certainly be a named storm in the far eastern Atlantic in the coming days.

A well developed tropical wave over interior Africa is forecast by all of the global computer models to move in to the eastern Atlantic and develop over the next five days. Conditions appear to be favorable across the entire swath of ocean this time around and we just might have something to track for days on end.

There is no doubt going to be a lot of talk about this system because the steering pattern looks to be one that could allow it track all the way to the United States. While this is a possibility, it is so far out in time that worrying about a specific location is pointless. Conditions appear to be favorable so let’s just watch and see what happens over the course of the week ahead and go from there. We have plenty of other issues to deal with on the west side of the Atlantic to keep us busy for a while longer.

I’ll post an update here later this afternoon or early evening once we get more info from the recon crew concerning 91L. I don’t think much will change with 99L today but if there is, I’ll certainly update that as well.

M. Sudduth 10:10 AM ET Aug 28

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Tropical storm looking more likely now

As we begin the long holiday weekend, residents of and visitors to the coast of parts of the Southeast may have to deal with a tropical storm. This is not typical of Memorial Day weekend but this year, it looks like we will break the norm.

The latest info from the NHC tells us that the area of low pressure between Bermuda and the Bahamas continues to get better organized, with a 90% chance of further development. That being said, it is hardly doing so at a rapid pace, this is not peak hurricane season with ample warm water around. As it is, we are essentially at the very beginning of the season and the amount of energy available is somewhat limited.

Intensity guidance from the over night model runs showing what would be a tropical storm forming over the next couple of days just off the Southeast coast

Intensity guidance from the over night model runs showing what would be a tropical storm forming over the next couple of days just off the Southeast coast

As the low moves towards the warmer waters of the Gulf Stream, there is a chance for it to strengthen and it could become a tropical storm before reaching the coast. The other scenario is that the low remains loosely organized and resembles more of a subtropical storm with winds spread out away from the center. Most of the computer guidance, some of which simulates the structure of tropical systems, indicates that this will in fact become purely tropical in nature – meaning that there should be a well defined center with organized bands of showers and thunderstorms closer to that center. This is what most people are used to seeing and I think that is what will happen.

Most of the track guidance suggests a landfall somewhere in South Carolina over the weekend. This means the obvious chance of heavy rain, some gusty winds and a churned up Atlantic. Beach-goers need to be especially mindful of local conditions – rip currents are part of the over all package of hazards that tropical systems bring with them. Do not underestimate the power of rough surf conditions, heed local surf advisories and keep the little ones very close to shore.

As far as other impacts, it’s too soon to know how much rain and who gets it. Once the storm forms and models get a better handle on its structure, that info can be fine tuned. You can bet on some locations receiving a few inches of rain but this is not the set up that we saw last October when hurricane Joaquin was off shore, peeling off insane amounts of moisture. There will be potential for heavy rain, but nothing like what we saw last fall.

The NHC mentions that the Hurricane Hunters will be investigating the low later today. Once we get the info, I will post another blog update here along with a video discussion for our app, Hurricane Impact, and on our YouTube channel.

M. Sudduth 8am ET May 27

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NHC showing likely development of “something” as we head in to the weekend

NHC 5-day outlook map showing the high chance of development for invest area 91L off the Southeast coast

NHC 5-day outlook map showing the high chance of development for invest area 91L off the Southeast coast

The area of interest off the Southeast coast, now known as “invest 91L”, is slowly getting better organized. The NHC has increased the chances of development in to the high category as we head in to the big holiday weekend.  But development in to what, exactly? That remains to be seen.

According to the latest statement put out this morning, a tropical or subtropical storm could form from the system as it approaches the coast this weekend. Let’s take a look at the differences between the two possible scenarios:

A tropical storm is what we are most used to hearing about. Winds are more or less concentrated around a well defined area of convection or thunderstorm activity close to the center.

A subtropical storm is more like a hybrid storm that has some tropical characteristics while also displaying some non-tropical signs as well – such as having winds and energy spread out over a larger area and more loosely defined convection. In other words, a subtropical storm hasn’t quite bundled all of its energy around a distinct, warm-core center like we are used to seeing with purely tropical systems, especially hurricanes. Subtropical storms usually transition completely in to classical tropical storms if they remain over warm water long enough.

In the case of 91L, right now, it remains spread out and not very concentrated, therefore, development has been slow. As long as this continues, we won’t see much more than a nuisance rain maker for the Carolina coast this weekend. However, water temps in the Gulf Stream, which is still to the west of the developing storm, are quite warm and it is possible that we will see a pure tropical storm form which would mean more wind, rain and rough surf conditions for the coastal areas that it impacts.

The good news is that none of the model guidance suggests anything too strong coming from this. After all, it is only late May, not September. That being said, we should never ignore a festering tropical feature that is so close to land. If you have plans along the beaches from Georgia to Cape Hatteras, keep them, but be aware of this feature and the potential for heavy rain and some gusty winds. The other hazard that would concern me is rough surf. Water temps along the beaches are still sub-80F but this will not keep people out of the water this weekend. Watch for local conditions to change including the chance of increased rip currents. Remember, tropical storms have the potential to be deadly if people don’t understand the local impacts. Keep an eye on the kids if they plan on heading in to the ocean in the affected area during the long holiday weekend.

I will post a video discussion concerning 91L later this afternoon followed by a blog post update here this evening.

M. Sudduth 9:50 AM ET May 26

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Texas deluge as tropical moisture aimed at Lone Star State

NHC graphical outlook and the potential track area of invest 91L

NHC graphical outlook and the potential track area of invest 91L

A lot has been made already about the presence of invest area 91L. After all, it is hurricane season and we do have an area of interest to monitor in a region that hasn’t had much activity over the past few years. In fact, a grand total of zero hurricanes have made landfall in Texas since 2008 – Ike was the last. While there is nothing at all to suggest that 91L will become a hurricane, it does raise a few eyebrows and for good reason: the rain threat.

May was an absolutely stunning month for rain in parts of Texas. Houston alone set records and had flooding issues. Farther inland, areas such as Austin, San Antonio and Wimberley experienced flooding which resulted in loss of life and significant damage. The power of water is often unappreciated until it changes lives and alters the landscape.

Enter 91L in to the picture and the NHC’s potential track area as seen in the graphic and you can see why Texans are probably a little more concerned about this system than they might be otherwise. None of the intensity guidance suggests anything more than a lopsided, weak tropical storm. Nothing to worry about, right? Wrong. Tropical cyclones, this includes tropical depressions and tropical storms mind you, have four main hazards that they can hit you with: wind, storm surge, rain and tornadoes (downburst winds too). The majority of the public responds well when the forecast suggests 150 mph winds are coming. Sadly, storm surge, as lethal as it is, seems to be ignored (see Katrina, Ike and Sandy).

That leaves us with rain, the most abundant of the tropical cyclone hazards and yet it is the most ignored and least understood by the average person. We think of rain as cleansing and necessary to sustain life. However, too much of it at once or even over several days has a drastic effect on life as we know it.

Only a few inches of rain in a short period of time can overwhelm flood control systems in large metro areas such as Houston. If the rain keeps coming, everything literally cascades in to a total disaster, often stranding hundreds of people who didn’t seem to know better. Even after years of “turn around, don’t drown” people will think they are immune to the laws of physics and do something that defies logic. All because they didn’t respect the power of rain and freshwater flooding.

What does all of this have to do with 91L? Plenty. I think this is an opportunity for people in the region, mainly Texas, to show that they have learned from past experiences. Allison in 2001 was quite a while ago, I’ll give them that. But the May floods were, well, in May – just a few short weeks ago.

There is the potential for what ever becomes of 91L, whether or not it attains tropical storm intensity, to drop a lot of rain over areas that simply don’t need it – at least not in the quantities that some forecasts are showing.

The good news is that upper level winds should keep 91L from becoming much more than a rain threat. This will minimize the amount of wind and surge impact to the coast. However, any onshore flow in areas such as Bolivar Peninsula could lead to over wash – that area is flat with little to no dune protection.

The bad news is that the Gulf of Mexico is ripe with moisture. Water temps are running above normal with actual temps close to the upper 80s along parts of the northwest Gulf. This will lead to an incredible amount of precipitable water being lifted in to the atmosphere and wrung out over Texas next week. Flooding is almost a certainty but exactly where is impossible to pinpoint.

It is going to be important for people in the region to monitor their local news outlets and reliable social media sources for updates. This is going to be a constantly changing situation and a lot will come down to how much rain falls over a certain area and for how long. Since that cannot be forecast with any real accuracy this far out, keeping up with the latest from the National Weather Service and your local TV meteorologists will be important in keeping you and your family safe.

I highly recommend using weather.gov and then inputting your ZIP Code. The return page will have a ton of useful links and information, including the latest watch/warning package and any special statements. It’s all right there at your fingertips – use it!

TS Carlos tracking map from the National Hurricane Center

TS Carlos tracking map from the National Hurricane Center

Meanwhile, Carlos is a tropical storm now just off the coast of Mexico in the eastern Pacific. The forecast takes the storm inland between Tuesday and Wednesday while strengthening it again to hurricane strength. Again, as with 91L in the Gulf of Mexico, the biggest issue with Carlos will be the potential for flooding rain. Certainly hurricane force winds are an issue but with a slow moving tropical system the rain is probably the larger concern at this point. Fortunately, the proximity of Carlos to land should keep it from intensifying much more than it is now, fluctuating back and forth between tropical storm and hurricane strength. Once inland in a few days, its moisture will spread over the interior portions of Mexico further extending the rain and flooding threat to that region.

I will have continuing coverage of 91L and Carlos tomorrow and via my video blog discussions now available through our YouTube channel. Follow and subscribe to the channel here: HurricaneTrack YouTube channel

M. Sudduth 12:15 PM ET June 14

 

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