Will predicted MJO pulse bring chance for first development of the season?

GFS MJO Forecast

GFS MJO Forecast

Even though we had tropical storms Alberto and Beryl already, they were both outside of the hurricane season. Since then, things have been nice and quiet. There are, however, indications that this may change. Let’s take a look at why.

There is an atmospheric phenomenon called the MJO or Madden-Jullian Oscillation that can sometimes lead to increased tropical cyclone formation when it is in its favorable mode. Think of it as a period of fertility in the tropics. A time when rising motion in the atmosphere is more prevalent, allowing deep tropical convection to form. This is what we call the “wet phase” of the MJO pulse and it typically adds a lot more showers and thunderstorms to the tropical regions of the globe where it circulates through.

On the other hand, the “dry phase” is easy to spot due to the sinking motion of the atmosphere, suppressing tropical convection. While development can take place during an MJO dry phase, it’s a lot more common to have development during the wet phase.

There are several computer models, the global models, that predict the MJO pulse and we can track that on various sites. The graphic I have linked to for this blog shows the operational GFS and its ensemble mean- the average of the various other runs of the GFS with slightly different variables. This model, along with others such as the reliable ECMWF, point to an increase in the wet phase of the MJO for the eastern Pacific and eventually the Atlantic Basin. When the MJO is within regions 8 and 1, we should begin to look for an increase in tropical convection. So, going by the graphic, we will need to pay closer attention to the tropics after about the mid part of the month as the wet phase moves through.

You’ll notice first, as it moves through the western Pacific, that we’ll see a typhoon or two develop followed by likely development in the southeast Pacific off the coast of Mexico and Central America. After that time, it is possible that a window of opportunity will open for the western Caribbean. It’s just another piece of the puzzle or a clue that we can use to know when the tropics are perhaps a little more ready for development than at other times. I’ll keep up with it and post more here as we get closer to the predicted date of the favorable MJO pulse.

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Hurricane season begins with no areas of concern

Today is the official start to the Atlantic hurricane season, but you already knew that. After Alberto and Beryl, today seems anti-climactic in some ways. Nature does not go by man made calendars, that much is certain.

As we look at the tropics today, all is quiet in terms of anything developing in the Atlantic or east Pacific. Even though water temps are warm enough in most areas, it takes more than just warm water to create a tropical cyclone. As we begin the hurricane season, I invite you to watch our video tutorial on understanding tropical cyclones and their hazards.

Florida Rains

Florida Rains

If you live in south Florida, it has been wet as of late. This is due to a piece of energy getting pushed out ahead of a trough of low pressure moving across the Gulf of Mexico. The result has been fairly heavy rain originating from clusters of showers and storms moving generally eastward across the Gulf. This region is favored this time of year for development but conditions do not support that at this time. However, off and on heavy bursts of rain will continue to move across the southern part of Florida for the next day or two before a more normal pre-summer pattern sets in.

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HurricaneTrack App for iPhone and Android coming soon

HurricaneTrack App

HurricaneTrack App

I wanted to post an update on our brand new app for iPhone and Android. Things are moving along nicely and we’re almost ready for submission to the App Store.

The app will be very specific in its features and will focus on being informative, educational and a powerful tool to use during hurricane landfalls. Here is a breakdown of the features:

Blog – it will contain our blog from this page which will be a handy way to keep up with our posts on your iPhone or Android device.

Daily video blog – each week day (when things are slow) I will post a short video blog outlining any potential development areas in the Atlantic or east Pacific. This will be a great way to keep up with the latest in graphical format with an easy to understand explanation. I can utilize this feature to educate our users about different aspects of tropical cyclones, preparedness, impacts of a pending landfall, etc. So when you’re waiting for the plane at DFW or ATL, you can sit back and catch up on the latest in the tropics using our app.

Twitter/Facebook – the app will have live Twitter and Facebook feeds, an important way for us to stay connected in short updates, especially when we’re on the road.

Web cam/GPS tracking from the Chevy Tahoe – this will be a really cool feature where users can track our progress on the road via a live web cam (still image, not live video) which will update at least once per minute. We’ll also have a GPS tracking map for you to know exactly where we are at anytime. This will be great for when we are uploading videos and pics, no guessing or wondering as to where we are.

Live weather data – this is likely to be one of the most popular features of the app and one that we are quite proud of. Users will have access to our live weather data and web cam pics from our three 5-meter wind towers that we will set up in the path of a hurricane. The data will include wind and pressure readings every 60 seconds! Each tower will also have a live camera sending still images to the app every minute as well. For those who really want to know what the wind speeds are, the pressure is and a look at the landscape where it is happening, this will be perfect for you!

Field mission video blogs – once we are out in the field working a landfall, our entire team will be able to post video blogs of anything that we find interesting or informative for you. We will use our iPhones to shoot the video segments and upload them immediately. We’ll do this before, during and especially after a landfall. There is no other app that will offer the amount of videos from the field than ours. You will be able to keep up with conditions in chronological order as we work the mission day by day. I am very excited about this powerful tool that will bring you the very best information right from where it matters the most.

So how much will it cost? We will roll out a subscription based app first followed by a free, ad-supported version. Both will offer the exact same features. Our hope is that our audience will support our work by subscribing to the app which will only be $1.99 per month. As they say, “you can cancel anytime”. But wait, there’s more! The app will be utilized during the off-season as well to provide a weekly weather outlook video as well as other interesting non-hurricane related news and activities. All in all, the app will be an extension of what we offer here and our more robust Client Services site. For those who are members of our subscription site and will also utilize our app, you will have the absolute best that we can possibly offer, covering you at all angles. We are very excited about the release of HurricaneTrack for iPhone and Android. We hope you are too. Any questions at all? Please post in comments or send an email. I’ll keep everyone posted as to when we expect it to be available in the App Store and Google Play.

 

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Beryl dropping a lot of rain over portions of the Southeast

TD Beryl continues to exert its influence over parts of the Southeast today with continued heavy rainfall. Northern Florida and southeast Georgia are receiving the most abundant rains and with the slow movement of the depression, this will continue to be the case throughout the next day or two.

Beryl is forecast to move in to South Carolina and then off in to the Atlantic near Charleston. At that point, the depression could strengthen back in to a tropical storm as it passes south of Wilmington and eventually, Cape Hatteras. I doubt that Beryl will be able to regain much intensity but it is possible that tropical storm conditions will be felt along the Carolina coast tomorrow and Thursday.

Flood watches have been posted for a wide swath of the southeast coast since the tropical rains are persisting long enough to create a flooding risk. Luckily, Beryl will move out of the picture this week and the heavy rains will go with it. The good news out of all of this is that the rain is badly needed. Beryl may have ruined the Memorial Day weekend for some folks but its longer term benefit of providing much needed moisture will outweigh most of the negatives associated with the pre-season storm.

I do not see any additional areas to be concerned about as we enter the official start to the hurricane season this Friday. The east Pacific is also nice and quiet after two recent tropical cyclones, one of which became a major hurricane.

Note: I will be posting a blog about our successful testing our weather balloon in Texas and the remote cam at the NOAA Sentinel in Mississippi last week. I’ll post pictures, video and the data that we recorded from the balloon payload later this week.

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Small but vigorous low pressure area, now labeled 93L, off the Carolina coast

The NHC is monitoring invest area 93L off the Carolina coast this weekend. The low pressure area spun up rather quickly in the wake of a larger storm system that has brought a lot of rain to the region over the last few days. Right now, the NHC is giving the system a 50% chance of becoming a tropical depression or even a tropical storm. Let’s take a look at a couple of things….

First, we do have a very well defined low pressure center at the surface. This is important because it’s the surface low that generates the deep convection – assuming that water temps and other atmospheric ingredients are in place. If the surface low were weak and poorly defined, then this would not warrant nearly the attention that it is currently getting.

Sea Surface Temperatures Map (Figure 1)

Sea Surface Temperatures Map (Figure 1)

Second, sea surface temps in the area (figure 1) are just warm enough to support the amount of energy needed to drive the deep thunderstorm activity, or convection, that is clearly seen on satellite and radar. We typically look for SSTs of around 80 degrees F or about 26 degrees C. The low is currently situated over just marginal temps to allow it to develop to the extent that it has. The question is: will it continue to thrive over the warm water or will the deep thunderstorms not be able to sustain themselves or even grow? This is part of what the NHC will be looking for when determining whether or not to name the feature a depression or a storm (if it is a storm, it would be Alberto).

NHC Computer Model Guidance (Figure 2)

NHC Computer Model Guidance (Figure 2)

The SHIPS intensity model, shown in figure 2, is definitely on board with this system becoming a tropical storm. Winds peak out at a healthy 54 knots which equates to about a 65 mph tropical storm. This may be a bit on the high side but a small system, such as 93L, can ramp up quickly given the right conditions. It can also fall apart just as fast if environmental conditions change, even a little. So far, there appear to be enough positive ingredients in place for 93L to have a chance of becoming a tropical storm before the weekend is out.

The steering mechanisms in place are weak for now which will likely mean a slow drift just off the South Carolina coast this weekend. Boating interests need to monitor the situation closely as local seas could get churned up with squally weather. It’s possible that 93L or what ever it eventually becomes, could reach the coast and bring rain and wind to the Carolinas. It will probably not be much more than an interesting topic of conversation and has no bearing on the rest of the up-coming hurricane season. These small low pressure areas are not too uncommon, especially this time of year. It does not mean the hurricane season will be more active than previously thought. The origins of this system are not from tropical sources such as a tropical wave coming from Africa. This is a left over piece of energy from a mid-latitude storm system that just happened to be in the right place at the right time.

I’ll post more about 93L tomorrow and will have short posts on our Facebook and Twitter pages.

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