The pattern is the key

Trough (shaded in red) is the key in steering the potential tropical storm as we progress through the week ahead

Trough (shaded in red) is the key in steering the potential tropical storm as we progress through the week ahead

We will have to wait and see how the steering pattern in the atmosphere evolves before we know what will happen with what is probably going to be the first tropical storm of the season. Before we get in to that in more detail, let’s look at what we know for sure.

First of all, what does “91L” mean? This is the designation given to a system that is in the development stage. The numbers 90-99 plus the letter “L” for Atlantic are used to signify an area of interest before it becomes a tropical depression or stronger. It helps with computer models, recon, satellite assets, etc. Once we get to 99L, we start over with 90L and so on. Got it? Ok, let’s move on.

As of early this afternoon, 91L continues to deal with some dry air to the north that is limiting its ability to push up deep, tropical thunderstorms. The process of convection is what helps to lower the air pressure and start the chain reaction going to spin up a tropical cyclone. The NHC mentions that it may not be until Wednesday before conditions truly allow for development.

So far, the weak low has moved southward to about the latitude of Jacksonville, Florida. We may see it begin to push westward some early in the week before it turns north again ahead of an approaching trough in the atmosphere. This trough is the key to where what will probably be TS Arthur ends up.

To put it in simple terms, if the trough is not fast enough or strong enough, then the would-be storm could track more north than east. This would mean a track closer to the North Carolina coast later this week. It is also possible that the trough swings by and misses the system completely- not likely, but not impossible.

The latest computer guidance suggests that the pattern will be just right to kick the system out to the northeast enough to keep it away from the coast, minimizing impacts to places like the Outer Banks. However, we are talking about four to five days or more in to the future and even the slightest changes in the pattern could lead to some serious forecast challenges.

What about intensity? This is almost impossible to speculate on right now. We do not even have a tropical depression yet so I do not feel comfortable pretending to know how strong this system could get. The obvious signs are there: warm water, more favorable conditions, etc. but this tells me nothing about how well organized the storm would be later in the week. Let’s wait for it to develop and go from there. I think we all know by now how tough intensity forecasting is, no need to spend time worrying about that at this point in time.

I realize that this potential threat comes at perhaps the most critical time of the year for beach interests. Hard to believe we’re looking at a possible tropical storm threat for the Fourth of July along the Southeast coast. For this reason, I think it is especially important to be aware of the impacts that this system will bring. A lot of people will be heading to the beach in the coming days from the Carolinas to Georgia, Florida and on up the rest of the East Coast. Even the lesser-talked about impacts such as rip currents and ocean swells need to be addressed. Careful explanation of the hazards is important so that people are not afraid to keep their plans but are aware of things such as rip currents or large, breaking waves.

I will keep posting updates here at least once per day. I’ll also have frequent posts on Twitter and our Facebook page. Social media is a great tool to utilize for weather information. This blog, as well as Twitter and FB posts, all feed in to our iOS/Android app, Hurricane Impact. I also add a daily, detailed video discussion exclusive to the app. It’s a great way to stay connected even if you’re on the go. Search Hurricane Impact in the App Store or on Google Play. I’ll have more here tomorrow morning around 9am ET.

M. Sudduth 1:40 PM ET June 29

Invest area 91L poised to develop but do so slowly

Satellite photo showing a slowly organizing area of low pressure just off the Carolina coast

Satellite photo showing a slowly organizing area of low pressure just off the Carolina coast

The NHC continues to increase the chances that the low pressure area off the Southeast coast will develop in to a tropical cyclone. This means it could become a least a tropical depression and probably a tropical storm.

Latest computer model guidance suggests that a slow process will continue as the low moves generally south and somewhat west of south over the next few days. Fortunately, the heavy weather will remain offshore but this has obvious implications for any boating interests and small craft especially should be aware of this developing situation.

An interesting run of the ECMWF model has generated quite the buzz on the hurricane social media circuit. It seems that the 12Z run was quite enthusiastic on developing 91L in to a moderate to strong tropical storm next week. We cannot worry about one run of any one model but it is noted and we’ll see if subsequent model guidance concurs and sets up a trend.

For now, folks from the Carolinas south to Florida should just keep an eye on the system. With quite a busy week coming up, people will be distracted and thus using social media, hurricane-related apps (we have one called Hurricane Impact), as well as television and radio will keep you informed without overwhelming you with info.

In the eastern Pacific, yet another tropical depression has formed but is forecast to move away from Mexico as it steadily develops in to a tropical storm. It poses no threat to land at this time.

I’ll have more here tomorrow in the early afternoon.

M. Sudduth 8:39 PM ET June 28

Erin of no concern, 92L has small window of opportunity to develop while the pattern begins to look very busy

Model plots for 92L in the southwest Gulf of Mexico

Model plots for 92L in the southwest Gulf of Mexico

There’s a lot to talk about this Friday so let’s get right to it.

First up, TS Erin continues to track WNW over the open waters of the east Atlantic but it is really beginning to struggle against the dry air. Add to this the fact that water temps where Erin is are marginal for supporting deep convection and the future of the storm does not look good. It won’t matter as Erin is forecast to move farther out in to the Atlantic, away from any land areas, and never be of concern.

Meanwhile, 92L has a small chance this weekend to become a tropical depression or weak tropical storm in the Gulf of Mexico. Upper level winds are not very supportive for development but, depending upon the track of the low, it could encounter an environment that would allow for some strengthening.

This system is complex and not typical of a potentially developing mid-August tropical system. Most of the heavy weather is located to the north and east of the center and is not wrapping around with distinct banding like we see in a more classic tropical storm structure. This should keep what ever strengthening that does manage to take place at a minimum.

Computer model guidance suggests a track towards the western Gulf of Mexico but I am not so sure that anything would be left to reach land. Most of the more advanced models break the system up over the next few days with minimal impact to land. Maybe we can get a little moisture to move over to Texas where they could use the rain – we will just have to wait and see.

ECMWF forecast for the MJO showing a very favorable pattern evolving over the next few weeks

ECMWF forecast for the MJO showing a very favorable pattern evolving over the next few weeks

The upcoming pattern looks very active as we head towards the end of the month and in to September. We have seen a very notable lack of upward motion or MJO activity in the Atlantic for the past several weeks. This has resulted in quite a bit of sinking, dry air across the tropics and we’ve seen the results of that with anemic tropical storms and no hurricanes forming. It looks like that will change in the coming weeks. The reason is the forecast for the MJO or Madden-Julian Oscillation which is looking more favorable for the Atlantic as we progress through the next several weeks. This should result in a dramatic uptick in activity across the Atlantic with the chance of seeing a hurricane develop as well. It will take a few more days for the pattern to evolve but the signs are pointing to a very busy end of the month and especially September.

I’ll post another update concerning 92L early this evening.

M. Sudduth 8:05am ET August 16

Android app almost ready as we get ready for peak season

Hurricane Impact for Android - coming soon!

Hurricane Impact for Android – coming soon!

I am happy to announce that the Android version of our app, Hurricane Impact, is almost ready. We’re putting the finishing touches on things now and expect it to be ready for sale on Google Play later this week.

Hurricane Impact is the only weather and hurricane related app that features its own live weather data, live web cam images and video reports from the field, during hurricane landfalls.

We take our own weather stations and set them up in the path of the hurricane or tropical storm. App users then have access to live wind and pressure data coupled with a live web cam image that updates once per minute. This is what we call high frequency data – meaning there is a lot of it! You won’t get a new wind reading every 5 minutes, 15 minutes or 30 minutes. It will be EVERY 60 seconds! Can you imagine watching the data streaming in during the eyewall of a landfalling hurricane? You’ll also watch as the pressure plummets as the eye passes over the weather station.

Add to this a live web cam image from the site of the weather station and you have an incredible, innovative and useful tool for truly knowing the impact of the hurricane at landfall. No other app on the planet has this ability- not a single one, not from equipment that was set up specifically for the hurricane.

This feature alone is awesome enough to be its own app! But, as the saying goes, wait! there’s more!

Hurricane Impact also provides users with our daily blog posts, Twitter and Facebook feeds and a daily video blog as well. We will also have content and blog posts from Mike Watkins and his site, Hurricane Analytics. You’ll have exclusive access to model plots, custom made for Hurricane Impact.

Speaking of video blogs- during our field work, the app is constantly updated with video posts from the landfall area. These are not some canned video reports from reporters who did a live shot for a network or local TV station, these are reports from our team produced exclusively for the app. If we think it’s important or interesting, we shoot it and post it to the app within minutes! You’ll have a chronological listing of all of our field reports during each landfall mission. The quality is outstanding and you can watch in full screen right on your device! It will be like you’re there with us every step of the way.

Hurricane Impact features the exclusive Surge Cam to monitor storm surge in real time

Hurricane Impact features the exclusive Surge Cam to monitor storm surge in real time

New for 2013, we have added an exclusive Surge Cam to the app. Storm surge is a major issue that coastal residents have to deal with when tropical cyclones make landfall. The National Hurricane Center is working on new storm surge products that will debut in the coming years. We went ahead and added a new Surge Cam to the app for this season. We will place a live, weather-proof camera unit in an area where storm surge is forecast to be significant. There will be a marker in the view of the camera to indicate how high the water is rising. App users may then watch as the water rises, creeping up the marker as the surge gets higher. The cam images will update at least once per minute right inside the app – no need to refresh, the image refreshes automatically. We will even show you where we placed the cam via a map so you can know right where you’re seeing the surge and its effects. Again, no other app has this innovative technology. We plan to add more Surge Cams in future updates – this is only the beginning.

We also have our very own tracking maps within Hurricane Impact. Most hurricane apps use NHC maps and just re-link to them. Not Hurricane Impact. We include our own, in-house generated tracking maps which include our exclusive ocean heat content tracking maps. These show the plot of the tropical cyclone over official TCHP or ocean heat content maps. This helps us to understand the heat potential in the ocean and how much energy may be available along the path of the storm or hurricane.

All of these incredible features are part of what makes Hurricane Impact a must have weather app for anyone interested in hurricanes. The cost for iOS or Android is $2.99 – one time fee. There are no hidden add-ons or annoying ads. Buy it once, we make updates and keep it fresh each season.

I’ll post an update the moment Hurricane Impact is available in the Google Play store. If you’re an iOS device owner, get it now for your device from the App Store. Search Hurricane Impact or click the “Get our app” link at the top.

As for the tropics, things are quiet in the Atlantic and look to remain that way for the week ahead at least. In the east Pacific, TD Gil and TS Henriette pose no threat to land as they move across the open waters of the Pacific.


Watching ex-Dorian very closely while Flossie nears Hawaii with heavy rain

Visible satellite photo of 91L (Dorian)

Visible satellite photo of 91L (Dorian)

The remnants of Dorian, labeled as 91L, are flaring up again today with quite a bit of deep convection noted in satellite imagery. However, surface pressures in the area are very high, near 1015-1016 mb and are not falling apparently. I think what we have is a vigorous tropical wave with perhaps a mid-level circulation. While it’s possible for the system to make enough of a comeback to be designated a tropical storm again, I think the odds are against it. Upper level winds are not going to let up enough and the background pressures are just too high.

With that being said, the wave of low pressure will bring showers and gusty winds to portions of the southern Bahamas, Cuba and south Florida over the next few days.

Looking at Flossie today, most of the deep convection has fizzled out which means the threat of heavy rain and strong winds is diminishing. There will still be periods of torrential rain as the bands from the storm move across the islands of Hawaii today and tonight. Any increase in deep thunderstorms will also bring some gusty winds down to the surface but I do not see any widespread issues with this system as it encounters cooler waters and less favorable conditions overall. Flossie will be out of the region by later tomorrow.

Elsewhere in the east Pacific, another area of disturbed weather has developed well to the southwest of Mexico. It will probably go on to develop in to a tropical storm over the next few days as it heads generally westward over the open Pacific.

Tomorrow, I will be working with Mike Watkins of Hurricane Analytics and our long-time friend and colleague to test much of our equipment that we’ll be using this season. He is flying to Wilmington, NC today from Florida to assist with the testing. We plan to set up and test our Surge Cams and a weather station for at least 24 hours. We’ll do the testing along the NC Outer Banks where the wind is nearly constant. It’s also a good area to simulate field mission conditions and to make sure things are running smoothly in an area that may be impacted later this season – you never know.

We’ll stream the entire event live on our public Ustream channel. In fact, I will change the homepage here tomorrow morning to the one we use during our field missions. It will have a live Ustream player console for both the live Tahoe cam and our live Surge Cam during the testing. As I stated back in March, we are dedicating one of our live streaming Surge Cams to public access this season. The other three will be reserved for our subscribers but we felt it was important to share with the public as much as we can at no cost. With the support we have from our members, we are able to do that this season and thus provide access, at no cost, to one of our live streaming Surge Cams.

In addition to the live video that we’ll be testing, we’ll also test the Surge Cam for our Hurricane Impact app. This cam is separate from our live edition. It is the same equipment but instead of live video, users see a live web cam image every 60 seconds. We will be setting up the Surge Cam for the app on this trip so anyone who has Hurricane Impact on their iOS device should check it out. We’ll also have the GPS tracking enabled so you can see precisely where we placed the cam.

Last but not least, for our app users, we will also test out one complete weather station along the Outer Banks. You’ll be able to monitor wind, pressure and a live web cam image within the app under the weather data section.

So if you’re bored tomorrow, join in and take a ride with us on our Ustream channel or right on the homepage of the site as Mike and I head out to the Outer Banks for this important round of testing. We’ll be live beginning around 10am ET and go through until late tomorrow night. We’ll pick up again Wednesday morning right on through late Weds night once our testing is complete.

I’ll have another blog post late tonight to update things on Dorian’s remnants and Flossie in the Pacific.

M. Sudduth