X marks the spot as tropics stay busy

NHC's Graphical Tropical Weather Outlook map showing several areas worth monitoring over the coming days

NHC’s Graphical Tropical Weather Outlook map showing several areas worth monitoring over the coming days

We are in prime time of the hurricane season and with the Atlantic Basin as warm as it is, it comes as no surprise really that there is plenty to talk about.

The NHC has several areas outlined this morning, including the remnants of TS Grace, that bear watching over the coming days.

First up, TS Henri is weak and is moving quickly now to the north. The forecast calls for a turn to the northeast as it transitions from a tropical storm in to a more spread out extra-tropical system over the far reaches of the North Atlantic. Seas will begin to subside in and around Bermuda where some beach erosion took place over the past couple of days due to the constant easterly swell that Henri was generating.

Henri could bring a period of heavy rain to parts of extreme southeast Newfoundland but the fast movement will limit the impact and its duration.

Next we have the remnants of tropical storm Grace moving towards the northern Leeward Islands. There has been a significant increase in deep convection with the system which could lead to periods of heavy rain and gusty winds as the low pressure area moves through. While there is little chance for it to become a tropical storm again, we know by now that rain alone is enough to cause major issues if too much falls at once. The forecast indicates that the remnants will track westward towards Puerto Rico over the weekend. We’ll have to watch and see what happens once the energy gets in to the southwest Atlantic or possibly the southeast Gulf of Mexico some time next week.

Off the coast of Africa is where the next large tropical wave is making its debut. The NHC is giving it a medium chance of development over the next five days and if it does in fact do so, it would be the 5th such development in the MDR or Main Development Region since late August. This is almost unheard of during strong El Nino seasons yet here we are, Danny, Erika, Fred and Grace all developed between Africa and the Lesser Antilles. This next system shows promise to become a hurricane over the open waters of the Atlantic in the coming days. As long as it remains away from land, so be it.

Finally, a small low pressure area has developed well to the southwest of the Azores Islands in the northeast Atlantic. It has only a small opportunity for development and of course wouldn’t be an issue for any land areas; something to watch but nothing to be concerned with.

To sum things up, there is plenty to keep track of but no major issues brewing in the tropics as of now. Enjoy the weekend, nice fall-like weather will be in store for much of the eastern part of the nation but then we return to the summer look and feel to things shortly, so take advantage of the cooler temps while you can! I’ll have a video discussion posted later this afternoon.

M. Sudduth 9:40 AM ET Sept 11

 

 

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Tropics busy but nothing set to impact land

Atlantic looking fairly busy considering the strong El Nino season

Atlantic looking fairly busy considering the strong El Nino season

We are closing in on the mid-point of the hurricane season in terms of climatology- September 10th marks the traditional peak of the season. Despite a fairly strong El Nino currently dominating the Pacific, the Atlantic Basin has managed to eek out enough activity to keep the maps active. Today is no exception with several areas to monitor in the coming days.

First, we have TS Grace which is likely to weaken and eventually dissipate somewhere in the Caribbean, if not before. It may bring additional rain to the region but it shouldn’t be too much and hopefully nothing like what Erika brought to Dominica recently.

Grace has little chance of making it to the United States as a tropical cyclone due to the persistent band of strong upper level winds and dry mid-level air situated over the deep tropics.

Next up is invest area 92L which is situated to the east-southeast of Bermuda this morning. The NHC says that it consists of a broad area of low pressure that is supposed to be nearly stationary over the next day or two. Water temps in the region are quite warm and most computer guidance suggests that this will become a tropical depression and perhaps a tropical storm before heading on out in to the far north Atlantic. No worries in Bermuda except for a possible increase in surf as the system organizes.

Elsewhere, a rather innocent looking tropical wave is moving through the southeast Caribbean Sea that could end up in a position where it could fester and try to develop down the road. The global models have been hinting at development somewhere in the western Gulf of Mexico within about a week. In fact, for what it’s worth, the often reliable ECMWF has been rather consistent with this scenario over the past few days. Right now, it’s just something to take note of but nothing more. I think that within 72 hours we’ll have a much clearer idea of what may or may not take shape in the Gulf of Mexico as we get in to next week.

Hurricane Linda satellite photo

Hurricane Linda satellite photo

In the east Pacific, hurricane Linda remains well offshore of Mexico and is expected to weaken as it moves to the northwest with time. However, this morning, it sure seems like it’s on a strengthening trend with a clearer eye showing up in satellite imagery. There is likely to be an increase in the wave action along portions of the Baja as the hurricane moves past but the heavy weather should remain far enough to the west to limit any additional impact. Some high-level moisture may get pulled northeast in to the Desert Southwest later in the week as the hurricane has a large circulation associated with it.

I’ll have a thorough video discussion posted later this afternoon that will take a closer look at all of the happenings in the tropics.

M. Sudduth 8:50 AM ET Sept 8

 

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After Fred, probably going to be quiet for a little while

Fred was an amazing event- bringing hurricane conditions to a small portion of the Cape Verde Islands yesterday; something not seen in well over 100 years in that region.

Now Fred is weakening as it encounters cooler water and more stable environment overall. The short-lived hurricane added a few ACE points to the season total which is now near 20 for those keeping score. ACE is the seasonal accumulation of actual energy that is output by tropical storms and hurricanes. Normally we see an ACE “score” of around 104 – most predicted 40 or less for this season. We are half way there and it’s only September 1.

Wind shear map from Univ of Wisconsin showing very strong winds (blue-ish color) blasting through the tropics

Wind shear map from Univ of Wisconsin showing very strong winds (blue-ish color) blasting through the tropics

So what’s happening now that Fred is on the way out? In short, not much. Take a look at the upper level winds on the graphic. I have highlighted the strongest band of upper level winds which are literally tearing across the deep tropics right now. We are talking about several thousand miles of ocean and the atmosphere above it that is essentially shut down from a tropical development stand point. Any westward moving tropical wave will be met with strong eastward moving wind that will literally tear the system apart.

There are some signs that this could change in the coming week to ten days but don’t look for anything drastic, maybe a slight relaxation of the shear. This would come as a more favorable MJO or Madden-Julion Oscillation migrates through the Western Hemisphere as indicated by the GFS and the ECMWF models. However, it doesn’t look to be very strong and as such, I don’t see much chance for any development over the next five to seven days.

Meanwhile, the Pacific continues to put on quite a show. Hurricanes Kilo, Ignacio and Jimena all remain out over open water, far from land. The record pace of the Pacific season is not just due to the El Nino but a warm north Pacific as a whole, something we have not seen in quite a while.

TD 14-E track map from the NHC

TD 14-E track map from the NHC

In the east Pacific, TD 14-E is forecast to strengthen in to a tropical storm as it tracks generally northward. However, conditions do not appear to favor a hurricane forming out of it and even if it did, weakening is indicated later in the forecast period. I see no reason for this to be an issue for the Baja or elsewhere along the Pacific coast of Mexico.

That’s it for now. Enjoy the fairly quiet start to September. This is typically the busiest month of the season, even in El Nino years. Will we end the month without a hurricane strike along the U.S. coast? Only one way to find out!

I’ll have more tomorrow.

M. Sudduth 11:30 AM ET Sept 1

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It’s mid-August, do you know where your hurricanes are?

Sea surface temperature anomalies showing the El Niño in the Pacific. Notice how much warmer the Pacific is than the Atlantic

Sea surface temperature anomalies showing the El Niño in the Pacific. Notice how much warmer the Pacific is than the Atlantic

Normally we would have had a hurricane by now in the Atlantic Basin. Normally.

This year is far from normal.

First of all, El Niño is in full swing along a vast stretch of the tropical Pacific. This abnormal warming of both the surface and subsurface waters has created all kinds of weather havoc with more to come. Luckily for those of us in the Atlantic, El Niño is typically a big bully to developing hurricanes.

Second up – wind shear and lots of it. Strong upper level winds blowing across the deep tropics, especially coming through the Caribbean, has done its job of keeping fledgling hurricanes from taking flight. This too is a common occurrence during El Niño years.

Saharan Air Layer still holding on in the tropical Atlantic

Saharan Air Layer still holding on in the tropical Atlantic

Third culprit – dry, sinking air. A lot is often made of African dust and the Saharan Air Layer but I think it sometimes gets more attention than it deserves. There have been quite a few impressive outbreaks of dry, warm air spewing off the Sahara in recent weeks and months but it is the overall pattern of dry, sinking air that has really put a lid, literally, on tropical development in the Atlantic. Any why not? With all of the warm water in the Pacific, the upward motion has been focused there while the Atlantic, though warmer than perhaps some had expected, is still out of balance and thus the non-rising nature to the atmosphere. This lack of general upward motion has been a serious impediment to development this season.

Now enter 96L in to the picture. What about its chances?

NHC 5-day Graphical Tropical Weather Outlook showing 96L and its potential development/track area

NHC 5-day Graphical Tropical Weather Outlook showing 96L and its potential development/track area

The National Hurricane Center is giving it a high chance of becoming a tropical depression sometime this week. After all, it’s mid-August, water temps are plenty warm and we have a well developed tropical wave and surface low moving across the deep tropics. It seems like it would be all systems go, right? Maybe but probably not – at least not this time.

Conditions for development are marginal right now though the water is warm, there’s no doubt about that. But warm water alone is not enough. The environmental conditions needed to produce deep, tropical convection just seems to be lacking once again in the tropical Atlantic. This was predicted very well in advance of the season by models such as the ECMWF seasonal forecast. In other words, it’s no surprise that we’re seeing such little activity. That being said, there is at least a chance that 96L makes it to become a tropical storm over the open Atlantic. If so, its name will be Danny.

Recent intensity plots for 96L

Recent intensity plots for 96L

Some of the intensity models indicate that 96L will become a tropical storm and eventually a hurricane. I just have a hard time seeing this considering the hostile environment ahead of the system. Never the less, we have something to watch now and as August comes to a close in a couple of weeks, we may have even more to watch. For now, the hurricanes have been shut out completely this season in the Atlantic and it looks to remain that way for the time being. We shall see.

Check out my video blog which will cover all of these topics and more – I’ll have it posted later this afternoon.

M. Sudduth 6:00 AM ET August 17

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Tropical Atlantic trying to produce activity in the face of overwhelming odds

Recent satellite photo of 94L off the west coast of Africa

Recent satellite photo of 94L off the west coast of Africa

The National Hurricane Center has recently identified an area of interest, a strong tropical wave with an associated low pressure center, not too far off the west coast of Africa. The tropical wave, labeled as 94L, is moving westward over warm water and actually has a slim chance at further development. However, the environment well ahead of this wave of low pressure is about as hostile as it gets. The combination of very strong upper level winds coupled with a generally stable atmosphere should clip the wings of this fledgling before it ever takes flight.

The global models are “seeing” this scenario as well and none are really doing much with 94L once it leaves the favorable environment that it is currently moving through.

It is interesting to note that after 94L seemingly dies off as it moves farther west that more strong tropical waves emerge from Africa in the coming days and also try to develop. I have to wonder – is the Atlantic just too hostile to allow any of them to flourish and become a tropical storm or hurricane? Or, is each one analogous to arrows being shot at a target: if you have enough, eventually one will hit. We are moving in to August very soon but it’s early August and even during a year without a strong El Nino, climatology tells us that eastern Atlantic development is rare until later in the month.

94L will be interesting to watch and will likely generate a lot of discussion within the hurricane blogosphere but from what I am seeing, that will be the extent of it. We never completely dismiss an area of interest and as such, I’ll be monitoring the future progress of this feature, even if it means watching from afar as it heads straight in to the sheer machine waiting to its west.

I’ll have more here tomorrow morning.

M. Sudduth 3:15 pm ET July 29

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