Model guidance duel continues as 99L tries to organize

Satellite image clearly showing that the low level center, weak as it may be, remains exposed due to strong upper level winds

Satellite image clearly showing that the low level center, weak as it may be, remains exposed due to strong upper level winds (click for full size)

The overnight runs of the various computer models did not really get us any closer to “knowing” the outcome of what becomes of 99L.

As it stands now, the tropical wave continues to slowly get better organized over the warm waters of the extreme southwest Atlantic – but I emphasize the word “slowly”. It seems that strong upper level winds are continuing over the system, preventing the thunderstorms from persisting and wrapping around the broad area of low pressure situated just north of eastern Hispaniola.

Despite the lack of organization, strong winds are being observed in the convection that itself is well removed from the low level center (poorly defined low level center). In addition, heavy rain is spreading over portions of Hispaniola and this is cause for great concern due to the risk of flash floods and mudslides. Remember, there are some fairly tall mountains in the region and tropical rain fall can lead to lethal flooding and tremendous damage.

The wave of low pressure is forecast to continue moving off to the west-northwest today and tomorrow, reaching the southeast Bahamas during that time frame. From there, it is likely to track through the Bahamas and toward Florida this weekend.

Early morning run of the HWRF model showing a strengthening hurricane in the eastern Gulf of Mexico in about 96 hours

Early morning run of the HWRF model showing a strengthening hurricane in the eastern Gulf of Mexico in about 96 hours (click for full size)

Now the tricky part: how strong does this system get – if at all? My answer: I honestly don’t know. The computer guidance is very confusing with the majority of the U.S. generated models, such as the GFS and the hurricane-specific HWRF model both showing little to no development, at least not in the short term. It is interesting to note that the HWRF, which stands for Hurricane Weather Research Forecast, is now indicating significant strengthening in the eastern Gulf of Mexico, around days 4 and 5. I am skeptical since that same model has had a very difficult time developing 99L much at all the past day or so.

On the other hand, consistency has been the rule for the much talked about ECMWF model or Euro. It has not strayed from its forecast of a possible hurricane impacting south Florida later this weekend. From there, it goes on to strengthen and make landfall up near the Big Bend area as a formidable hurricane. Needless to say, this is quite concerning but exactly how much stock do we put in to it? I just don’t know what to make of all this right now. On the one hand, the remarkable run to run track record of the Euro makes me think it could have the correct overall solution – that being a potential hurricane for some portion of Florida in the coming days. Conversely, the lack of development seen by the GFS and the waffling of the HWRF model for track and intensity makes me wonder: will anything happen at all?

ECMWF from the overnight run showing tropical storm conditions for the southern portion of Florida this weekend

ECMWF from the overnight run showing tropical storm conditions for the southern portion of Florida this weekend

All of this is not good for the public and the perception of how hurricane forecasting is “supposed” to be. Usually we don’t keep waiting and waiting just to see if a system will develop. The advantage, if you’re going to have to deal with a hurricane, is knowing it is coming in the first place. The “what if” scenario here is a little unsettling.

Let’s suppose that 99L does indeed wait until 24 hours before landfall in south Florida, assuming it does in fact take a path in that direction. If it were to quickly intensify over the very warm waters, how fast would it ramp up? Could it become a hurricane rapidly? Yes it could. We’ve seen it before but it’s been a while. Katrina in 2005 was on a fairly steady pace to strengthen as it approached SE Florida from the Bahamas but we at least knew it was a strong possibility well ahead of time. People will react better to a named storm or a hurricane headed their way than to a tropical wave. At least that’s my thought on the matter. This is a tough situation as the longer we wait, the less time there is to get ready if the need arises. While we would all like to wish that everyone along the coast was prepared anyway, we know the reality and it makes for quite the sitting duck in situations like this.

The afternoon runs of the various models (actually based on morning data) will be quite telling – or not. Questions about whether or not the GFS steps it up and develops 99L may be answered. What if it has the answer already and nothing much is going to happen to begin with? Maybe if the Euro suddenly shows little to no development we can at least say, ok, two major global models now show a low impact event. We will just have to wait and see. Either we know more or are stuck with dueling models once again.

I will post more here this afternoon including my daily video discussion.

M. Sudduth 8:50 AM ET Aug 25

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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

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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

 

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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

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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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