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

Joaquin poised to make historic landfall

Satellite photo of hurricane Joaquin

Satellite photo of hurricane Joaquin

It all began as a rather innocuous area of spin in the mid to upper levels of the atmosphere a little more than a week ago. What was once just an upper level low, producing some showers and thunderstorms over the warm Atlantic, is now hurricane Joaquin. Most hurricanes form from other sources such as tropical waves that emerge from Africa. Joaquin is unique – it is that rare hurricane whose origins can be traced back to a system that is cold in the middle, not warm like a hurricane. And so here it is and so here we go with the anguish of worrying about where it ends up. The potential for something historic is on the table and those who know my writing know that I rarely use terms like that.

First – the stats. As of 8am ET, Joaquin was a 75 mph hurricane moving towards the central Bahamas. This is the first region that will have to deal with the effects which may be quite intense as the hurricane continues to intensify over very warm ocean water. As such, hurricane warnings are up and people in the region are hopefully preparing. The slow movement is a problem too – it means a prolonged period of wind, rain and surge for the Bahamas.

Once Joaquin turns north, and it should according to the official forecast, things get very interesting. A lot was made about the fact that the ECMWF model, considered to be the world’s best by many, nailed the evolution of what eventually became devastating hurricane Sandy. Somehow, the model “saw” the track as far as seven days from the landfall in New Jersey. All the while, the American based GFS model handed Sandy’s energy off and sent it packing out to sea. We all know the end score – Euro > GFS.

Here we are three years later and another global model duel is at hand. This time, Joaquin is the name and the end result is still in question. Why? We are talking about less than five days, maybe six at the most. How can the global models not be locked on the solution that can give forecasters confidence that their track and intensity ideas have solid merit? Basically, it’s the pattern.

Sandy was very unique in that a Caribbean hurricane moved up in to the southwest Atlantic and was then pushed out to the northeast and away from the United States – only to be blocked by an enormous ridge of high pressure which sent it back towards the Mid-Atlantic where a deep, strong trough captured it. The set-up for Joaquin is similar yet different. This time, it’s going to be early October. The trough in question is going to cut off from the main flow and not be nearly as strong as the one that captured Sandy. Water temps are quite a bit warmer this time than what they were in late October 2012. Joaquin has a chance to make landfall purely tropical with a concentrated area of winds and the potential for a devastating storm surge. When and where that could happen remains to be seen.

GFS (left) vs ECMWF (right) and their positions of Joaquin at 102 hours

GFS (left) vs ECMWF (right) and their positions of Joaquin at 102 hours

This brings me to the GFS vs ECMWF duel.

Check out the graphic showing the GFS track from the overnight run (6z). Clearly it curves around the cut-off low and bends back towards the North Carolina coast. This would be a very bad scenario for obvious reasons.

Now look at the ECWMF position at the same time – 102 hours. The difference between the two positions of Joaquin is incredible and means a completely different outcome for each model.

One has to wonder why such a spread between the two global models? I wish I knew. Obviously, the GFS captures Joaquin with the cut-off low and swings it back towards the coast. The ECMWF, on the other hand, finds just enough of an escape route offshore to allow the hurricane to turn safely away from the United States. Which solution will turn out to be correct? Well considering that the ECMWF seemingly lies alone in its “thinking”, it looks more and more like the other models, the GFS included, have locked in on what will eventually be a nasty hurricane event for some location(s) along the East Coast.

If the ECMWF turns out to be correct, it will be an incredible turn of events and mean that the current track forecast that we see now will be turned almost sideways, pointed eastward instead of towards the coast. It’s possible but at this point, it’s hard to believe the GFS, which had more data from the NOAA G-IV mission last night, will be totally wrong and eventually flip to the “out to sea” track. I guess anything is possible with weather so we shall see.

Precipitation forecast over the next 5 to 7 days showing incredible rain fall for parts of the East

Precipitation forecast over the next 5 to 7 days showing incredible rain fall for parts of the East

All of that aside, what can you expect if you live along the East Coast? Well, for one thing, rain! The trough and upper level energy coming in to the Southeast and East will set off a significant heavy rain event even before the supposed arrival of Joaquin. Take a look at the precip forecast map from the Weather Prediction Center – notice how vast an area is covered by 6+ inches of rain over the next several days. Add the effects of a hurricane to the mix and we have the set-up for what I term a history making event. Flooding from freshwater is astonishingly lethal. The fact that the Appalachians could get excessive rain makes me very nervous. The Piedmont is also very vulnerable in this kind of set up. I urge people to make sure they are aware of the weather forecast for their local area. Use weather.gov as a source – read the warning info, the discussions and tune in to your LOCAL TV and radio sources. This much rain, combined with a potential landfalling hurricane, is simply too much to ignore and brush aside as hype. This situation could have lingering impacts for years to come and people better be paying attention.

As far as direct impacts from Joaquin – the Bahamas are up first, then we wait. If current forecast trends continue, it looks like a hurricane strike for North Carolina, Virginia or even points north. Swells will move out ahead of the hurricane which will make the already battered beaches even more battered. Surfers will love it but swimmers will need to simply stay out of the water. The rest is up to the hurricane and where it ultimately tracks. We can look at what impacts to expect when and if that time comes – there is still time for the ECMWF solution to be correct and save the day – wouldn’t that just be something?

I will produce and post a video discussing further outlining much of the content that I covered here. I expect to have that online by later this afternoon. As always, you can follow along in our app – Hurricane Impact (two words) in the App Store and on Google Play.

M. Sudduth 9:40 AM ET Sept 30


Fluke run of global model or something to be concerned about?

Overnight run of the ECMWF model showing potent storm impacting the Mid-Atlantic coast next week

Overnight run of the ECMWF model showing potent storm impacting the Mid-Atlantic coast next week

I almost could not believe my eyes this morning when I checked the various global models for signs of tropical cyclone activity over the coming days. The GFS showed a few areas in the longer range worth watching but nothing too serious. The ECWMF, on the other hand, had me thinking, “where have I seen this before?” I had to make sure I was looking at the correct time of the run. I was.

What the ECMWF shows is a similar situation that lead to Sandy last year, almost eleven months to the day. It seems that a piece of energy comes out of the eastern Gulf, across Florida and then develops in to a storm over the southwest Atlantic. That storm, maybe a mix of tropical and subtropical, then moves back to the northwest, towards the North Carolina coast before coming inland somewhere over the Mid-Atlantic early next week.

The one major, extremely important difference here is that the feature that the Euro is showing does not originate as a powerful hurricane coming out of the Caribbean Sea. Instead, this storm would be fueled more by energy in the atmosphere than deriving it from the ocean. However, it is possible that, due to the very warm waters of the southwest Atlantic, that we could see a hybrid type system out of this.

What is very interesting to me is the striking similarity of the high pressure area coming down out of Canada to block this storm from heading out to sea as the GFS clearly shows it doing. This blocking pattern would prevent the would-be storm from escaping and in fact would send it back towards the coast.

Also note the time frame here. The Euro shows this event unfolding over the next five to seven days, not eight to ten. While not exactly short-range, it’s not 240 hours out in the future either. And, the Euro is not alone with this scenario. The Canadian global model also shows this storm event, albeit quite a bit stronger as is often the case with that particular model due to how it handles the physics of heat sometimes. So this is something we should keep an eye on. While not nearly the extreme case that Sandy was, the track, time of year and overall look of the pattern is worth watching closely over the next few days. Needless to say, any significant ocean storm coming in from the southeast towards the Mid-Atlantic would be very much unwelcome news. Hopefully the Euro and the Canadian had a fluke run and all will be right again in subsequent model output. We shall see.

Elsewhere, the tropical Atlantic is nice and quiet with no substantial threats of development seen in the global models for the time being.

I will post a quick update on the potential Mid-Atlantic storm later this afternoon after the 12Z run of the ECMWF becomes available.

M. Sudduth 8:40 am ET Sept 24

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.

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:


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:


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….