Hurricane Sandy lashes Jamaica on its way to Cuba, the Bahamas and then where?

Sandy became a hurricane today as it approached Jamaica. In fact a fairly distinct eye is showing up in satellite imagery. It could be that Sandy strengthens more before reaching Cuba late tonight/early tomorrow morning. Obviously people in the region should be ready for the effects that Sandy will bring as it closes in on Cuba.

Once over Cuba we should see Sandy lose some of its strength, especially considering the high terrain of the area. However, the threat of extremely heavy rain is serious all across eastern Cuba and over towards Haiti.

All of this mess will spread northward in to the Bahamas as the very large circulation  of Sandy progresses northward. Expect an increase in wind, rain and surf throughout most of the Bahama islands later tonight and throughout the day tomorrow.

As we look at Florida, the main issue will be strong winds along the coast of the eastern portion of the state. Look for winds to gust near 50 mph by Friday and Friday night. This could cause power outages for a large area of the eastern peninsula especially if Sandy takes a more westerly course in the Bahamas.

The other serious issue is going to be beach erosion and the large, breaking waves that Sandy will generate as it approaches and passes by. Keep in mind the astronomical high tides that are going to only increase as we approach a Full Moon. Surfers will need to be very cautious as the ocean will be quite agitated from Sandy’s expanding wind field.

Looking ahead in the forecast it appears now that North Carolina will likely experience serious wind and ocean issues as Sandy tracks northward Friday. The Outer Banks are especially vulnerable and we could see substantial coastal flooding. I urge people to keep tabs on the local hurricane info put out by the National Weather Service. There is fantastic, local information that can help to better understand the impacts expected from Sandy.

Even the coasts of Georgia and South Carolina will experience an increase in wind and surf conditions, possibly leading to beach erosion there as well. So much depends on the eventual track of Sandy and how strong it becomes once in the Bahamas.

Keep in mind too that a lot of heavy rain will spread in to Florida and the rest of the coastal Southeast with Sandy and its huge cloud shield. This could easily lead to localized flooding and the loosening of tree roots which can help to topple trees. Plan on power outages over a wide part of the Southeast coast.

Then we need to be concerned about the Northeast and/or Mid-Atlantic states. It looks like the Euro model’s idea of a powerful storm affecting the region late in the weekend or early next week is plausible if not quite possible. We need to wait a little while longer to understand better what Sandy will be structure-wise. This is where things get very complicated since the hurricane will be interacting with mid-latitude atmospheric energy that a lot of people are not used to hearing about. I’ll talk a lot more about the impacts from Sandy for areas north of the Carolina coast in future blog posts. Right now, we need to see what happens farther south in Florida and the Southeast. Needless to say, it looks very likely that a substantial storm system is headed for areas that normally do not deal with such extreme events. People need to pay attention to their local weather info sources and be ready to act when needed.

I’ll have more here tomorrow morning.

 

 

 

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Sandy nearly a hurricane and poised to become historic event one way or another

Sandy's wind field will ikely expand and could bring tropical storm conditions to a large part of the Southeast U.S.

Sandy's wind field will ikely expand and could bring tropical storm conditions to a large part of the Southeast U.S.

It is going to be a rough day in Jamaica as Sandy is nearing hurricane intensity this morning. Luckily, there is no eye readily apparent in satellite imagery which would indicate significant strengthening but I think it is only a matter of time before Sandy becomes the 10th hurricane of the season.

Jamaica will feel the effects today and tonight followed by a landfall in Cuba early tomorrow morning. The interaction with the higher terrain of eastern Cuba will disrupt the inner core of Sandy and should keep it from being too strong once in the Bahamas. However, sea surface temps are plenty warm there and it would not be surprising to see Sandy regain hurricane intensity while passing through the Bahamas.

Late tomorrow and in to Friday, Florida’s east coast will begin to feel the effects of Sandy wit an increase in wind and surf. Right now, the upper Keys and a good portion of SE Florida is under a tropical storm watch. Since the wind field of Sandy is forecast by the global models to expand significantly, I feel that it is almost a certainty that winds to at least tropical storm force, perhaps up to 50 mph, will be felt across portions of southeast Florida.

The other issue will be the huge wave set up that is going to happen as a result of Sandy’s massive wind field. Beach erosion is likely to be a major concern for east facing beaches along the Florida coast and working up the Southeast coast in to North Carolina. I cannot emphasize this enough and with the growing Moon phase towards full, we could be looking at a major coastal flood event for some areas of the Southeast U.S. coastline. A lot will depend on how far west Sandy tracks as some of the models are indicating a brief jog back to the northwest in a few days. Interests along the Florida east coast all the way up to the North Carolina Outer Banks should be paying close attention to this situation. The chance for substantial ocean overwash, especially in the Outer Banks, seems to be increasing with time.

Then we have the issue of the ECWMF’s idea of an unprecedented impact to the Northeast with Sandy or what ever it becomes once past about 35 N latitude. The model has not given up on its forecast of a general northward track, just passing the Outer Banks and then slamming the Northeast with what looks like hurricane conditions over a large area of coastline. While the GFS remains strong in its forecast of an out-to-sea track, it has been getting a little more west and north with each run. Even if the Euro forecast turns out to be dead wrong, Sandy will leave its mark down south along the Florida east coast and probably the North Carolina Outer Banks. If the Euro is right, then we will remember the ending of the 2012 hurricane season for many years to come.

I’ll have another update posted here by early this evening.

Keep in mind that we do have our iPhone app which is a great way to keep up to date with the latest on Sandy and other tropical news and info. I post video blogs to the app each day with several of them posted daily as needed during such events as this with Sandy. During field missions, our app is the ONLY one that offers live weather data from our own instrumented wind tower. Plus, we set up live web cams and post video updates from the field on a regular basis. You simply cannot find this level of dedication and information WHERE THE ACTION IS from any other hurricane tracking app. To get HurricaneTrack for iPhone, iPod Touch and even the iPad, click here.

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A few thoughts on Sandy

TS Sandy developing banding as it gathers strength in the Caribbean Sea

TS Sandy developing banding as it gathers strength in the Caribbean Sea

There are no sweeping changes to discuss tonight with Sandy but I did want to pass on a few observations and thoughts before turning in for the night.

First, Sandy appears to be getting better organized with deep convective bands beginning to develop and wrap around the east side of the circulation. There is still some drier mid level air and perhaps a little bit of wind shear along the western half but all in all, the structure looks improved over the last few hours. This should equate to a gradual lowering of the surface pressure and an increase in the winds. Interests in Jamaica need to be ready for an intensifying hurricane later tomorrow. If Sandy were to begin a period of rapid strengthening, then the effects of the wind will be quite dramatic, especially in higher elevations.

The other item to note is the almost certain effects that Sandy will have on Florida and elsewhere along the Southeast coast. People need to remember that hurricanes are not points on a map. Just because the center is not forecast to strike Florida does not mean all will be fine and dandy – especially along the east coast. High surf, an increase in rip currents, strong east to northeast winds will all be factors as we approach the weekend.

What people in Florida, along the east and southeast portion mainly, need to realize is that Sandy is going to grow in to a much larger system over the next few days. Its wind field is going to expand and reach out far from the center. This means effects will extend in to areas such as the Keys, Miami, West Palm Beach and all across southeast Florida. Exactly what conditions will be felt is impossible to forecast but it looks about as certain as can be that there will be some impact from Sandy for Florida.

Of course, in the Bahamas, hurricane conditions are possible and probably expected. Here too the surf will increase with larger and larger waves developing around this growing storm system.

I think that too many people ask “what category is it?” and if it’s not a three or four, they don’t worry too much. It’s not about worrying at all. It’s about understanding the weather and its potential to cause harm to you and your property. It is possible that winds to 50 or 60 mph will impact areas of SE Florida. This can cause damage to weak structures and trees. These trees can fall on people, buildings and cars and have bad results.

I want people to try and get the bigger picture of what is going on here with Sandy. Sandy is not an “it” as in, “where will IT go”. I think people are asking about the center when they say “IT”. Sandy is a large, powerful tropical cyclone that has wind, rain, storm surge and the chance for down burst winds and tornadoes in its outer rain bands. When you think of “IT” think of the whole package.

These conditions may spread across a huge geographic region from Florida north through the Carolinas and eventually in to New England. It is extremely important to grasp what the effects will be and why they will take place. Do not focus on category this or that, that does little good. Instead, ask yourself “what impacts will I have here?” and then do your part to read up on those. Where can you do that? Your local National Weather Service site for one. Go to weather.gov and put in your ZIP Code. Read the forecast discussions, learn about the impacts. There is a lot to gain from educating yourself about possible effects from any weather system, much less a hurricane or powerful ocean storm.

For now, we will watch and hope for the best for people in Jamaica, eastern Cuba, Haiti and eventually the Bahamas. Just remember, Sandy is not a dot on a map, paper or computer, it is a huge weather machine and it’s on the move. Be ready.

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Complex situation as model duel plays out

It has been an exceptional year in terms of how two of the world’s best global models have performed. I am speaking of the American generated GFS or Global Forecast System versus the European generated/supported ECMWF or European Centre for Medium-Range Weather Forecasting. Both models are highly sophisticated and provide a vast array of products for forecasters around the globe. However, both have had their share of issues over the years when it comes to forecasting tropical cyclone events.

Let’s take a look at TS Debby back in late June. The GFS was forecasting a turn to the northeast as a trough of low pressure dug in to the eastern portion of the U.S. On the other hand, the ECWMF was forecasting a ridge to build and push Debby back to the west. Here is a paragraph from the NHC’s discussion regarding Debby on June 24:

“THE TRACK FORECAST IS EVEN MORE COMPLEX. THE GFS INSISTS ON A TRACK TOWARD THE NORTHEAST AS DEBBY BECOMES EMBEDDED WITHIN A LARGE MID-LATITUDE TROUGH. HOWEVER…THE ECMWF AND THE HWRF BUILD A RIDGE TO THE NORTH OF DEBBY AND FORECAST A WESTWARD TRACK. GIVEN THE WESTWARD TURN INHERITED FROM THE PREVIOUS FORECAST…AS WELL AS THE HISTORICAL STRONG RECORD OF THE ECMWF…THE NEW OFFICIAL FORECAST MOVES DEBBY INITIALLY A LITTLE BIT TO THE NORTHEAST TO REFLECT CURRENT TRENDS BUT THEN TURNS THE CYCLONE BACK TOWARD THE WEST OR WEST-NORTHWEST IN 24 TO 36 HOURS. A MAJORITY OF THE GFS ENSEMBLE MEMBERS NOW ARE CONSISTENT WITH THE DETERMINISTIC RUN…WHICH WAS NOT THE CASE YESTERDAY…MAKING A STRONGER CASE FOR THE EASTWARD SOLUTION. WE MUST BE READY TO MAKE A CHANGE OF THE FORECAST TRACK AT ANY TIME.”

Note the reference to the ECMWF and how it has a “historical strong record”. Well, as it turned out, the ECWMF was wrong and Debby ended up turning north in to the Florida panhandle.

Forecast for Debby showing west track towards Louisiana

Forecast for Debby showing west track towards Louisiana

Later that day, the new forecast, which was the correct forecast, shows Debby headed north in to Florida panhandle

Later that day, the new forecast, which was the correct forecast, shows Debby headed north in to Florida panhandle

Now let’s fast-forward two months to Isaac in late August. Here again we had two significant differences between the GFS and the ECMWF. The GFS wanted to take Isaac north and in to a trough after entering the Gulf of Mexico, putting a substantial threat to the Florida panhandle and even the west coast.

Meanwhile, the ECMWF showed a much farther west track towards Louisiana. Here again is a quote from the NHC discussion on Isaac from August 22:

“HOWEVER…THE ECMWF CONTINUES TO SHOW A STRONGER RIDGE…AND THUS SHOWS A MORE WESTERLY MOTION THAN THE OTHER MODELS.”

As it turned out, the ECMWF was correct in a stronger ridge and Isaac ultimately made landfall in southeast Louisiana.

So what does this have to do with the current situation with Sandy? For the first few days of the forecast period, not much. Right now, the GFS and ECMWF are pretty close to each other since the pattern is fairly straight-forward right now. Sandy is forecast to move slowly northward and bend east of north and pass over or very close to Jamaica. Both models “agree” on this.

Then, both models have Sandy passing over eastern Cuba and in to the central Bahamas by around 72 hours. It’s after this time frame that the two models part ways and have two vastly different outcomes.

The GFS basically moves Sandy slowly to the northeast and out of the Bahamas. While the ECMWF takes Sandy more north by day four but also fairly slowly.

At day five, the GFS has Sandy roughly half-way between Florida and Bermuda while the ECMWF is quite a bit back to west, near 30N and 75W.

It seems that the GFS wants to hand off Sandy in to the Atlantic due to lower heights in the middle layers of the atmosphere because of a large ocean storm, partly the remnants of Rafael. This provides and escape route for Sandy to take, like a rock gradually rolling down a slope, not too steep, but just enough to build momentum and begin rolling. Sandy is the rock heading down the gentle slope.

The ECMWF does not allow Sandy to feel the slope, so to speak, and keeps it farther back to the west, much closer to the Southeast U.S. coast. Then, all “you know what” breaks loose with that model.

By day six, a significant deep trough of low pressure digs in to the west of Sandy and causes the flow to turn more from the south out over the western Atlantic. Instead of pushing Sandy out like a broom sweeping across the floor, the trough instead scoops Sandy up and swings it back to the northwest and eventually in to New England as a powerful hybrid storm. Basically, the trough “captures” Sandy and pulls it in, not allowing it to turn east and out to sea like the GFS shows. The result is a remarkable storm for the mid-Atlantic and New England; the so-called “storm for the ages” that I alluded to yesterday.

Which solution will be right? I have no idea. I can see why both models show what they show but I also know that the GFS tends to have a bias in handing off tropical cyclones in to lower height fields more often than not. In other words, the GFS is taking the easy way out and sending Sandy in to the Atlantic. The ECMWF does not do this and instead keeps Sandy in the western Atlantic long enough for the big trough to dig in and capture it, creating a large ocean storm of epic size and strength.

Day seven of ECMWF showing powerful storm as Sandy gets drawn in to trough in the East

Day seven of ECMWF showing powerful storm as Sandy gets drawn in to trough in the East

There is a lot of talk about this situation in the weather blogosphere. Opinions about both scenarios abound and some folks simply refuse to believe such a wild scenario with the ECMWF. However, considering its track record in the long term, it has to be considered and thus, once Sandy is in the Bahamas, the story will begin to unfold as to what ultimately ends up being the true course that it will take.

In the end, one of these two powerhouse global models will end up being correct. Which one that is will have enormous implications on the weather for millions of people along the East Coast of the U.S. towards the very end of the month. Stay tuned, this has only just begun….

 

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Sandy likely to become a hurricane as it nears Jamaica

I have a feeling that Sandy is going to be a lot stronger than forecast. Why not? Intensity predictions are where there is the least amount of skill when it comes to tropical cyclones. Sandy is currently situated over some of the warmest, highest heat content water in the Atlantic Basin with an obvious building area of high pressure in the upper levels of the atmosphere. This should lead to a period of quick strengthening and people in Jamaica better be ready for the potential of hurricane conditions over the next couple of days.

Not much has changed today in the future track concerns for Sandy. It looks as though eastern Cuba and then the central Bahamas will take a direct hit from the storm (hurricane?) with plenty of heavy rain spreading across a good portion of the Greater Antilles.

What the models seem to all indicate is that Sandy will continue to strengthen once over the extreme southwest Atlantic Ocean in about three days. Here too water temps are very warm and undisturbed this hurricane season. As with Jamaica, I am concerned about portions of the Bahamas having to deal with an intensifying hurricane sitting on top of the area. Keep in mind too that Sandy is not forecast to move very fast, this will only prolong the effects in any given area.

Now, for the part where folks along the U.S. East Coast have to pay attention. The long range models are split in to two distinct camps. The GFS and its related modeling ejects Sandy out in to the Atlantic on a northeast track, easily staying away from the U.S. coastline.

On the other end of the spectrum, the two non-U.S. generated models, the ECMWF and the Environment Canada CMC models both show Sandy getting stuck in the pattern, trying to turn out but then hooking back northwest to north with a landfall along the Northeast coast. What is most concerning, but almost certainly overdone, is the absurd intensity that the models are suggesting. It is my sincere hope that there is just something not right with what the Euro and Canadian predict for the long range. If they are even close to being correct, Sandy could transition in to one heck of a hybrid mix the likes of which the region has not seen in almost a generation.

As I mentioned earlier today, even though there is a lot of interest in what happens a week from now, we need to be sure to stay focused on what may be a hurricane threat in and coming out of the Caribbean Sea. We’ll have loads of time to see how the steering pattern evolves once Sandy gets in to the Bahamas.

I would also like to mention that I believe we will see some strong winds, out of the east and northeast, for portions of the Florida east coast in the coming days. This will lead to an increase in rough surf and possible dangerous rip currents. And, if Sandy tracks closer to the coast than forecast, it is possible that tropical storm conditions could be felt in some areas of extreme SE Florida. This is a very complex situation and one that will end up affecting people across a large geographic swath.

I’ll have more here tomorrow morning including a new video blog posted to our iPhone app. I will also be watching closely to see how far west Sandy tracks and if it warrants a field mission to coastal Florida later in the week. I think the next 48 hours will tell a lot about the future for Sandy and what impacts the U.S. will feel.

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