Two areas of development likely but far, far from land

93L (left) and 95L (right) both show promise to develop in to tropical depressions over the next day or two

93L (left) and 95L (right) both show promise to develop in to tropical depressions over the next day or two

The deep tropics remain fairly active, despite the strong El Nino in place in the Pacific. Fortunately for coastal dwellers, none of the systems that the NHC is monitoring pose any threat to land.

Up first is invest area 93L, the western most disturbance. As you can see in the satellite photo, it certainly has that look of becoming a tropical depression and may do so later today.

Computer models suggest a short window of opportunity for it to strengthen in to a tropical storm, if it does, it would be named Ida….unless…..

Unless 95L, the eastern most system develops first. It too has become better organized overnight but I think that 93L is well on its way to becoming a depression and eventually a storm.

Steering currents are such that both systems will almost certainly turn north with time and remain well away from land areas. In the end, we could finish the week with two additional named storms and a few more ACE points for the season but that’s it.

Looking ahead, the long range global models do not indicate any solid leads as to where the next area of interest may be. The natural evolution of the season would suggest that we begin watching the western Caribbean and Gulf of Mexico this time of year but upper level winds have not been favorable at all this season across that region. Water temperatures are slowly coming down from north to south as well and so the sands in the hourglass of the hurricane season will begin to run out quicker as we head towards October. It’s not over until it’s over, no doubt about that, but for the next several days at least, the United States and surrounding countries of the western Atlantic Basin are safe from the threat of hurricanes.

In the eastern Pacific, there are no areas of concern right now and I do not see that changing over the next five to seven days.

I’ll have more here tomorrow.

M. Sudduth 8:20 AM ET Sept 16

Tropical Atlantic showing signs of life with 93L

5-day graphical tropical weather outlook map from the National Hurricane Center showing 93L over the tropical Atlantic

5-day graphical tropical weather outlook map from the National Hurricane Center showing 93L over the tropical Atlantic

There has been a lot of talk in recent weeks about how hostile the environment is in the tropical Atlantic when it comes to hurricane development.

Dry air, cooler than average sea surface temps, African dust – it’s all part of the so-called “anti-hurricane season” going on in the deep tropics. So far, the negative conditions has meant there has been absolutely nothing to talk about between Africa and the Caribbean Sea; that is, until now.

It seems that conditions have become a little less hostile in recent days with a let up in what is known as the Saharan Air Layer or SAL. Also, water temps have warmed some in the region compared to where they’ve been over the past month or so. Add to this mix a vigorous tropical wave that exited Africa a few days ago and we have an area of interest: 93L.

The National Hurricane Center indicates that the disturbance has a small window of opportunity for some development over the next day or so as it moves across the deep tropics. However, it is still a bit early for development this far east and eventually, upper level winds are likely to put a lid on strengthening for 93L.

It is interesting to me that we are seeing this happening simply because the deep tropics are supposed to be very unfavorable this hurricane season. While I won’t make too much out of this system’s presence, I do take note of it and will be watching the region a little closer in the coming weeks. Perhaps conditions won’t be quite as negative out that way as some were thinking, time will tell.

For now, it is just something to watch as it travels westward over open water. There are no indications at this time that it will develop much further but even if it does, it is still far out over the Atlantic and would not be an issue for any land areas for several days at least.

Track map showing hurricane Dolores over the eastern Pacific

Track map showing hurricane Dolores over the eastern Pacific

Meanwhile, in the east Pacific, what was once powerful hurricane Dolores is weakening well to the southwest of the Baja. The forecast track takes it northwest to a position that could send fairly significant moisture towards the Southwest U.S. in the coming days. This might help to enhance the rain chances across southern California, Arizona and Nevada. How much so remains to be seen but it’s something to keep an eye on for both beneficial reasons and the potential for flooding.

It’s also worth noting that high surf could be an issue for south facing beaches in southern California as swells generated by the hurricane reach the coastline this weekend. Surfers will obviously love this scenario but need to be careful out there as the sets roll in.

I will have more here over the weekend concerning 93L and Dolores.

M. Sudduth 6:45 AM July 17

Disturbance in SW Gulf could mean a lot of rain for part of south Florida, but will it develop?

Gulf disturbance, also known as 93L, forecast to bring copious amounts of rain to parts of south Florida later this week

Gulf disturbance, also known as 93L, forecast to bring copious amounts of rain to parts of south Florida later this week

The situation in the southwest Gulf of Mexico is fairly complicated. We have the energy from what was once tropical storm Trudy in the southeast Pacific. This energy crossed over Mexico and is now festering again in the southwest Gulf of Mexico. In fact, convection is on the increase this morning and the NHC has bumped the chances of development up to 40% now.

Model guidance suggests that upper level winds are not all that bad for additional development. Water temps are plenty warm and the region is still within a favorable MJO pattern which supports upward motion in the atmosphere.

However, none of the computer models are showing much in the way of robust development, none of them show a hurricane out of this, not yet anyway.

What is more likely to happen is that we see a weak, spread out tropical storm develop and move towards the east or east-northeast, in the general direction of Cuba and Florida. This means there is potential for a lot of rain in the coming days for parts of south Florida. Some guidance suggests upwards of 8 inches of rain or more for the Keys and other areas of extreme south Florida. Obviously this could change either in amounts or locations over the coming days but people in south Florida need to be ready for a possible big rain event.

Whether or not this disturbance eventually becomes a tropical storm remains to be seen. As I mentioned, I do not see any evidence just yet that this holds much potential for being a stronger wind event. The rain effects will be enough of an issue, believe me! We will see how things develop and go from there. At least it is not in a hurry to move or develop quickly.

This is the only area of concern that could impact land. Ex-Gonzalo is moving quickly towards the northern portions of the United Kingdom where strong winds, rough seas and heavy rains are expected later today and tomorrow.

Another area of disturbed weather is located way out in the far eastern Atlantic. It may have a chance to develop more over the fairly warm waters of the region but it won’t have any significant impact on land.

In the Pacific, tropical storm Ana is moving south of the Hawaiian islands and will turn north across the atoll islands west of Hawaii. Ana is expected to become a hurricane again but will be moving past any land areas at that time with minimal impact overall.

I will have more here on the situation in the Gulf with a post later this evening. I am back from Bermuda where a near perfect intercept of Gonzalo took place. I will be posting a full write-up, complete with video and data info that was collected, by later in the week.

M. Sudduth 10:55 AM ET Oct 20


Tropical depression forming from 93L this morning?

Intensity graph showing considerable spread between the regional hurricane models and the larger scale global models

Intensity graph showing considerable spread between the regional hurricane models and the larger scale global models

There is not a lot of it, but deep convection is finally developing around at least part of the circulation of 93L. It is limited to the southern half of the low pressure area and any additional increase, especially on the northern side, would easily bring the system to tropical depression status – maybe even to tropical storm strength as well.

It is remarkable how well the low pressure area has held together amid such dry conditions in the deep tropics. This pattern has been in play for the past few years and, in this case for sure, has kept hurricane activity in this region to a minimum.

Taking a look at the latest intensity guidance, there are mixed signals this morning. Some of the model data suggests that this could become a hurricane while other data maintains a weak system that actually stays weak throughout the coming days. Breaking it down a bit, the regional hurricane models, developed just for predicting the intensity of tropical cyclones, are more bullish on development than the larger scale global models. The GFS, for example, shows the system basically dissipating as it moves across the northern Caribbean Sea. I think that there is a small window of opportunity for 93L to become a tropical storm before more negative conditions hinder additional strengthening. We’ll see – as I have said all along, I am skeptical of deep tropical development right now due to the fact that nothing much has come from this region in quite some time.

The track forecast seems a little more straight forward and indicates a general west to west-northwest movement towards the Lesser Antilles. As such, interests in the area should be watching the progress of 93L closely. While it looks like the impacts would be limited due to the low intensity, it is possible that tropical storm conditions will arrive in the region over the next few days. We’ll see what the NHC has to say about all of this around 11am ET when the first advisory could be issued on what could be tropical depression three or even tropical storm Bertha.

Elsewhere in the Atlantic Basin, all is quiet as we end the month of July.

In the east Pacific, there is plenty of activity to watch but nothing close to land and I see nothing in the computer guidance to suggest a change to that anytime soon.

I’ll have more here later today with additional updates on our Twitter and Facebook feeds.

M. Sudduth 8:07 AM ET July 31

Well developed circulation but missing the muscle (convection)

There is no doubt that if the environment around 93L were more moist, we would be looking at a strong tropical storm, soon to be hurricane. The circulation pattern of the system is very impressive. However, it lacks what it needs the most: deep convection.

Convection is what drives the heat engine of tropical cyclones. The air rises, condenses in to clouds, produces copious amounts of rain and this releases heat in to the atmosphere. Without sustained thunderstorm activity, or what we call convection, the process cannot move forward and the system will have a tough time strengthening.

Even in the face of all of this dry air down in the deep tropics, 93L does have a substantial circulation as seen clearly on satellite animations. If and when it can develop persistent convection, it will then intensify and easily become the next tropical depression and possibly tropical storm Bertha.

Right now, because it is fairly shallow in the atmosphere, it is moving almost due west with the low level flow. Should it acquire the convective activity that I mention, then it will likely begin to move more northward with time. This should place the would-be storm somewhere in the northeast Caribbean Sea over the weekend. Obviously, interests there need to monitor this situation closely.

Some of the computer guidance still holds on to the idea that 93L will eventually become a hurricane but I have my doubts. On the other hand, I also know how hard it is to predict intensity with tropical cyclones. The odds are not in favor of much strengthening but it is not wise to completely dismiss the idea that 93L could become at least a category one at some point.

Beyond the weekend, much will depend on how strong this becomes. Right now, the advanced global models show it weakening under strong southerly shear and thus is moves towards the southeast Bahamas. If it were to be stronger, it believe it would be further north but still fairly close to the Southeast U.S. to warrant some concern. It is tough to say as a lot can happen and again, we’re talking about many days in to the weather future. Sometimes, you just don’t know for sure.

Elsewhere in the Atlantic Basin, nothing is going on to be concerned with at the time. And in the east Pacific, there is plenty of activity to watch but it is all located well out away from Mexico, so no worries there.

I will post another update concerning 93L early this evening.

M. Sudduth 11:43 AM ET July 30