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

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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

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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

 

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Bertha by mid-week? Seems likely at this point

NHC graphic showing potential path of developing system in the Atlantic, designated as 93L

NHC graphic showing potential path of developing system in the Atlantic, designated as 93L

The tropics are about to get active and this time, it could stick.

The NHC is monitoring a tropical wave, now designated as invest area 93L, far out in the deep tropics. While this region has been quite hostile up until now, it appears that the tables are about to turn and we will likely get the next named storm, Bertha, within a few days.

Global computer models are coming in to agreement that the tropical wave will develop steadily in the coming days as it moves generally west to west-northwest.

Water temps are okay for development but are certainly not running above normal in the region. This might keep the system from developing faster, we’ll see. The presence of dry air all across the deep tropics may also inhibit development even though there are indications that this pattern is about to let up some.

The track appears to be generally westward with a gradual bend to the west-northwest with time. Keeping this in mind, interests in the Lesser Antilles should be monitoring this feature closely. The NHC’s five day outlook graphic suggests a path towards the islands. After that point, it is just too soon to even begin speculating on where this might end up. We know the drill by now: it could turn north and eventually away from the United States or it could continue west enough to eventually affect land somewhere after a potential encounter with the Caribbean islands.

One thing that interests me quite a bit is the fact that, if this system develops, it would be several weeks ahead of the usual time frame that we look this far east. It would also signify a change in the overall hostile pattern for the deep tropics. In short, this could indicate that we are in for a different hurricane season than originally forecast. The El Nino failed to develop thus far and now that we are seeing development in the deep tropics, it may be that the forecast of a below average season is in jeopardy. I do not want to put too much in to this but considering just how hostile the region between Africa and the Caribbean has been for the past year at least, I do wonder if we are seeing a change that could lead to more long-track systems that do not fall apart.

The rest of the Atlantic Basin is quiet as we start the week. I see nothing to worry about anywhere outside of 93L.

In the east Pacific, things remain quite busy with weakening TS Hernan moving away from the Mexican coastline. Other areas to monitor dot the Pacific but none pose any significant threat to land right now.

I will post another update on 93L later this evening after more information comes out from the global models and the NHC.

M. Sudduth 9:27 AM ET July 28

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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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