A lot of rain for the eastern 3rd of U.S. but no tropical troubles per se

A lot of rain heading for the East as deep moisture rides out of the warm Gulf of Mexico

A lot of rain heading for the East as deep moisture rides out of the warm Gulf of Mexico

The tropics are busy with hurricane Nadine and now two areas of interest, 92L and 93L, to keep an eye on over the coming days.

However, conditions are just not ripe for anything significant to develop across much of the western and central Atlantic or the Gulf of Mexico. A combination of dry mid-level air and fairly high wind shear should limit any development of either of these two invest areas.

Meanwhile, hurricane Nadine is stuck in the pattern it seems and will be bothering the Azores Islands this week with possible hurricane conditions. After that, Nadine is going nowhere fast as the steering flow is such that we could be talking about it a week from now; still out over the eastern Atlantic.

One side effect of 93L in the western Gulf is its moisture that will feed in to an approaching cold front sweeping across Texas right now. Plenty of deep moisture will be lifted north and east over the week ahead and with it, the chance for heavy rains across portions of the eastern U.S., especially in the mountains. Just be aware of this as too much rain in short order can cause quick flooding problems.

We’ll watch 92L as it moves in to and across the Caribbean Sea. This is the time of year to look for development in that region but as of now, none of the dynamic global models indicate much at all.

I have covered all of this and more in our daily video blog for the HurricaneTrack app for iPhone. If you own it, check it out now. If not, get the app today via the link above or by searching “hurricanetrack” in the app store from your device. I’ll have much more here tomorrow morning.

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TD7 not much of a threat while Ernesto will live on…in the east Pacific

Conditions across the tropical Atlantic are just not very favorable right now. There is simply too much mid-level dry air and pockets of unfavorable upper level winds are widespread. For these reasons, it looks as though, once again, the global models will be correct in forecasting what will likely turn out to be a very weak system in TD7.

Looking at the latest satellite photos, there is very little convection and the envelope of energy with the depression is fairly small. As the NHC noted on their early morning discussion, this makes it vulnerable to effects such as dry air and shear more so than a larger, more potent circulation would. I do not see TD7 being much of a problem for anyone unless of course there is a sudden and unexpected change in the environmental conditions ahead of it. I doubt it.

Meanwhile, something remarkable is going to happen. Think about this…the tropical wave that became hurricane Ernesto has traveled from Africa, all the way across the tropical Atlantic, through the gauntlet of the eastern Caribbean Sea, made landfall twice in Mexico and is now poised to emerge in the east Pacific where it can live another day. That’s right, Ernesto, or at least a bulk of its energy, is about to finish quite an incredible trek across the mountainous terrain of Mexico to cross in to the east Pacific. Now, it will not be named Ernesto if it does in fact regenerate, which is very likely to happen. Instead, it will take on the next name of the east Pacific, Hector. It is quite rare to have a tropical cyclone cross over land from one distinct basin to another. What’s even more interesting about this, there is a possibility that the regenerated system could eventually affect the Baja region. Who would have thought this to be the case a week ago or more when we were tracking something that, at one point, could have ended up making landfall anywhere from Florida to Texas. Now, it’s eventual final landfall could easily be along the Pacific coast of Mexico. Needless to say, folks in that region need to monitor what happens and I’ll post updates about it here along with video blogs in our HurricaneTrack app throughout the upcoming weekend.

The remainder of the Atlantic is somewhat busy with invest area 93L off the coast of Africa. Here again we see that conditions are only marginal for development and the global models show next to nothing over the next week to 10 days anywhere in the Atlantic, Caribbean or Gulf. I am not sure if it’s climatology (i.e. we are simply still just a little too early in the season to see prolific, sustained development) or if something else is going on related to the growing El Nino in the Pacific. I’ll take a closer look in today’s video blog to be posted in our app this afternoon. What ever the reason, it’s great news for coastal dwellers who will not have to deal with any hurricanes this weekend for sure and probably all of next week as well.

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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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