Wet weekend ahead for portions of the Gulf Coast as low pressure tries to form

A Wide Swath of Heavy Rain Coming for the Gulf Coast

A Wide Swath of Heavy Rain Coming for the Gulf Coast

It looks like a wet weekend is in store for a good deal of the northwest Gulf Coast due to a low pressure area that is forecast to form. The low drops southeast out of Texas today and tomorrow and begins to tap the very warm waters of the Gulf of Mexico. This will supply quite a bit of deep tropical moisture and could lead to some very heavy rains across portions of the I-10 corridor later in the weekend.

The low seems to be part of energy coming out of the east Pacific associated with a developing tropical storm just about on the coast of Pacific Mexico now. What the models are indicating is that some of this energy gets pulled in to a developing trough of low pressure that digs in over Texas, Louisiana and Mississippi this weekend. The added heat energy from the Pacific system gets a boost of upper level energy from the trough and a surface low develops in response over the northwest Gulf of Mexico. It is quite complex but the end result should be a non-tropical low pressure area gets going and brings wind, coastal flooding issues and very heavy rains to a good deal of the area from Texas to Alabama between late Saturday through Monday.

While I fully expect to see the NHC mention this system once it gets organized, the processes involved with its development lead me to think that it has almost no chance of becoming purely tropical in nature. However, there is an opportunity here for the formation of a sub-tropical storm which has winds spread out over a larger area and temperature profile that is different from a purely tropical system where the winds are concentrated nearer the center that itself is warmer than the surrounding environment. The bottom line is that a period of rather squally weather is coming and folks need to be aware.

As it happens to be, I am about to head over to the Gulf Coast as I make my way to Houston for continuing interview work for a documentary that I am producing with my colleagues Mike Watkins and Jesse Bass. So I will be right in the thick of what ever develops and can post updates here, stream live via our Ustream channel and send video blogs to our iPhone app. It will be an interesting weekend to say the least.

Meanwhile, the system in the east Pacific, invest area 94-E, is producing heavy rains and winds to near tropical storm intensity in the area near the southern Baja peninsula. Fortunately, the weak low pressure center will be onshore later today but the threat of continued torrential rains across portions of Mexico will persist for the remainder of today and early tomorrow. All of this energy will track across Mexico and become the source of the aforementioned Gulf low.

ECMWF MJO Signal Looking a Little More Favorable in October

ECMWF MJO Signal Looking a Little More Favorable in October

Beyond this weekend, it looks as though a weak MJO pulse could move in to the Atlantic Basin just in time for the second climatological peak of the hurricane season that occurs near the middle of the month. While it is too far out in time to begin looking for signs of development, I suspect that we will see something take shape in the western Caribbean within the next two to three weeks. This fits the time of year we are in and the added influence of the wet phase of the MJO could lead to one more development potential during October. Obviously, we will just wait and see how this plays out as there is nothing indicated in the long range models just yet.

As I mentioned, I am on the road right now, currently in Florida, where I have interviewed quite a few people for the documentary. I’ve been working with Mike Watkins to develop the story and shape the ideas in to something that we think will give you a whole new perspective on hurricanes and their impacts on our nation and our culture. I’ll be producing video blogs for our private clients and for our app later this morning and then I’ll hit the road by this afternoon and begin heading over to the Gulf Coast for more interviews. I’ll keep the site updated with another post coming by early this evening.

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As we end September, tropics look to remain peaceful

I am on the road in Florida shooting interviews for our upcoming documentary due out in March. However, it is still hurricane season so let’s take a look at what’s going on across the tropics today.

Nadine is still on the maps as a moderate tropical storm. The forecast keeps Nadine around for the next five days as it moves over warmer sea surface temps. However, increasing shear should eventually take over and hopefully weaken the storm enough to dissipate it. We shall see, Nadine has been around for a while now.

Elsewhere in the Atlantic, all is quiet with no areas of development expected nor seen in the various global model forecasts. While October can be a busy month, I do not see much to suggest that we will see any significant development over the next week to 10 days. Once we get in to mid-October, that could change but we’re talking almost three weeks away.

In the eastern Pacific, Miriam is weakening and is no longer forecast to impact the Baja peninsula as the low level center will fade westward as the mid and upper level energy gets sheared off and heads in to Mexico, bringing some rain but that’s about it.

I’ll post more tomorrow as I continue to travel around Florida.

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Nadine back on the maps as we watch Miriam in the east Pacific

TS Nadine Over SSTs Just Warm Enough

TS Nadine Over SSTs Just Warm Enough

If you were sick of hearing about Nadine, well, you might want to cover your eyes for the next week or so because it’s back as a tropical storm again. Since Nadine was not swept up in to the north Atlantic in recent days, it has been allowed to meander in the eastern Atlantic and as high pressure builds to its north, the storm will be moving back westward. This will place Nadine over water temps that are just warm enough to allow for it to re-develop and that is already taking place. Top winds are estimated to be near 60 mph with a pressure of 986 mb. By later in the coming week, the storm is forecast to become a hurricane again and this will continue to add points to the ACE index, which now stands around 90. This index measures the amount energy expended by Atlantic tropical cyclones. Nadine will add several more points over the coming days, like a basketball team blowing out its opponent but they keep running up the score.

Elsewhere in the Atlantic Basin, all is quiet with no areas of organized convection seen in satellite imagery. None of the global models develop anything over the next week or more either. I do not think we’ll have much to be concerned with until we get to about mid-October when there is a secondary peak to the hurricane season coming up. More on that later.

TS Miriam Track Map in the East Pacific

TS Miriam Track Map in the East Pacific

In the east Pacific, tropical storm Miriam continues to strengthen well to the southwest of the Mexican coastline. It is forecast to become a hurricane and it could eventually turn back towards the Baja peninsula as the steering pattern begins to change over the northeast Pacific. How soon this turn happens and how strong Miriam will be at that point is difficult to tell right now. Interests along the Baja should keep up with Miriam’s progress.

Quick note to remind our iPhone app owners to update the app to the most current version. We have added 5 tracking maps of our very own plus a new home screen and manual refresh buttons on our social media feeds. These are vast improvements over the original version which debuted on August 1. So go to the App Store on your device and get the update. If you don’t already have HurricaneTrack, get it now and enjoy a daily video blog plus our new maps and plenty of landfall features when we are active in the field.

I’ll have more here tomorrow.

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September likely to end quiet, but what about October?

With the exception of TS Nadine, which is gradually losing its tropical characteristics, and 94L, itself a sub-tropical type storm system, the Atlantic Basin is very quiet. There are no additional organized areas of deep convection noted and none of the global computer models develop anything over the next several days.

In the east Pacific, invest area 93-E shows signs of becoming the next tropical depression but it will move away from Mexico. Thus we will likely end September without a hurricane threat to the U.S. or Mexico. Leslie did bring near hurricane force winds to Newfoundland earlier in the month but that’s it, we have escaped the peak month without a serious landfall event. Remarkable considering all of the activity that we have seen but since it has all been out of the deep tropics and over the open ocean, the result has been no issues to speak of for land.

The Western Caribbean is favored during the month of October

The Western Caribbean is favored during the month of October

How about October? What can we expect as we enter the last significant month of the hurricane season? Well, climatology suggests that a lot can happen. The patterns shift back to the western Atlantic and especially the western Caribbean Sea in terms of development potential. Sea surface temps in the region are at their peak with plenty of deep ocean heat content available. We’ve seen some incredible October hurricanes with the most notable in recent times being Wilma seven years ago. It developed towards the end of the month and was at one time the most intense Atlantic hurricane ever recorded with a central pressure of at least 882 millibars and a 2 mile wide eye. Wilma went on to menace the Yucatan before making landfall in SW Florida on the 24th of October. That was the last time any hurricane has made landfall in Florida, much less a major hurricane.

Will this October have something to track in the western Caribbean? Obviously I do not know for sure but there are couple of things to look for which might help to uncover a few clues.

First, as I mentioned, climatology suggests that we should see at least one hurricane develop in the western Caribbean or vicinity during October. This region is favored with plenty of development taking place over the past 100 years. In other words, we would normally look to the western Caribbean and/or Gulf of Mexico in October for the highest potential for development.

ECMWF MJO forecast not yet showing a favorable period for the western Caribbean

ECMWF MJO forecast not yet showing a favorable period for the western Caribbean

Second, the MJO or Madden-Julian Oscillation. The best way to describe this phenomenon is to think of it as a period of time when upward motion in the tropics is favored, thus allowing for deep convection to develop and sustain. The MJO typically moves around the globe once every 30 to 40 days and helps to kickstart tropical convection. Sometimes it is quite weak and hardly noticeable. Other times, it is very prevalent and leads to a burst of several tropical cyclones over a two week period or more. Right now, the MJO favors western Pacific development and none of the dynamic models indicate that it will move in to the western Caribbean anytime soon. However, once we get past the end of the month, I suspect that we’ll see some changes and as we approach mid-October, I would not be surprised at all to see a chance of something developing. If we get a favorable MJO pulse, those odds will go up considerably.

Finally I think that the lack of a significant El Nino event will also help to increase the chances of an October hurricane in the western Caribbean. El Nino usually means stronger than normal winds cutting across the Caribbean due to an increase in upward motion over the tropical Pacific. So far, the warming in the Pacific has been weak at best and we are not officially in an El Nino yet. This may be just enough to allow for one or two more hurricanes to develop before the season ends on November 30.

For now, the tropics are of no concern and won’t be for the next few days and probably longer. Once we get in to October, we’ll have to watch the climatologically favored areas for the possibility of something coming along to track. Let’s see how these other indicators help with monitoring conditions that may lead to such development. In the meantime, have a great weekend and enjoy the Fall weather. I’ll have more here on Monday.

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Subtropics rule the season

Hurricane Chris set the tone for the remainder of the Atlantic hurricane season

Hurricane Chris set the tone for the remainder of the Atlantic hurricane season

It has been a rather odd hurricane season so far. I say this because most of the activity, the stronger activity anyway, has developed well outside of the usual breeding grounds of the deep tropics.

Hurricane Chris, which formed back in the latter half of June, did so at 41.1 N latitude! That is incredible for so far north so early in the season.

Next up was hurricane Ernesto, the only hurricane to form south of 20 N latitude this season out of eight total hurricanes so far. However, Ernesto struggled to become a hurricane until right before landfall, another common trait this season as we’ll see with Isaac.

Gordon became the season’s third hurricane and again, well outside of the deep tropics, attaining hurricane status at 34.0 N latitude while heading for the Azores Islands.

Then there was Isaac. Several times during Isaac’s life span it looked as though it could become a powerful hurricane. Instead, Isaac struggled with dry air and the lack of an inner core all the way in to the north-central Gulf of Mexico. One private weather firm loudly proclaimed that Isaac could be another Katrina or worse! And yet the fourth hurricane of the season only managed to reach 80 miles per hour before making landfall in Louisiana. While Isaac was a large hurricane and caused significant flooding from surge and fresh water flooding, it was not a very convectively active hurricane with a well defined inner core. This kept the winds at flight level that were being measured by recon from reaching the surface. Fortunately for residents of the central Gulf Coast, Isaac was only a fraction of the intensity that we all know it could have been had environmental conditions been more favorable.

It took all the way until hurricane Kirk on August 30 to finally get a category two hurricane. And of course, this happened while Kirk was well out of the deep tropics, affecting only shipping interests.

Leslie also had promise to become a large and intense Atlantic hurricane but it too fell far short of that potential and spared Bermuda with only passing tropical storm conditions. Stronger winds and more pronounced effects were felt in Newfoundland but even here conditions were not as bad as what could have been experienced had Leslie been a much stronger hurricane.

Michael is the season’s only category three hurricane so far and guess what? It made it to this intensity at 29.6 N latitude while out over the open central Atlantic over water temps of about 80 to 81 degrees. That’s it. Just enough to get the small hurricane to really ramp up – and it maintained a strong eye feature for several days. Luckily, Michael was far from land and only padded the ACE index score for the season.

We are still tracking Nadine which has been on the map since the 11th of this month. Nadine became the season’s eighth hurricane on the 14th at 30 N latitude. This is remarkable and a sign that something is definitely “wrong” in the deep tropics this year.

I have heard everything from El Nino to mid-level dry air being responsible for the lack of intense cyclones in the deep tropics. I am sure researchers such as Dr. Philip Klotzbach at Colorado State University will be looking in to the source of this unusual pattern and I look forward to learning more about it myself at next year’s National Hurricane Conference in New Orleans. The obvious benefit here has been a substantial reduction in damage resulting from less intense hurricanes impacting land. What if Ernesto had become a 140 mph cat-4 at landfall along the Yucatan? What if Isaac had become another Katrina and brought 30 feet of surge instead of 12? We know the answers….it would have been horrible. Been there, done that. I am sure no one is complaining about the feeble nature to this season’s hurricanes. I hope too that people are curious as to why? Why would conditions be so hostile in the deep tropics? What was the root cause if it can be pin-pointed down to something that simple? Will this pattern continue for the next several seasons? While we can be thankful for the lack-luster performance of this year’s hurricanes thus far, I think understanding the mechanics of such good fortune (it’s relative, I know, as plenty of people are still cleaning up after Isaac) is important in case we see the reverse take place next season or next month for that matter.

In any case, it all boils down to this: the tropics have been strange this season and strange has meant fairly benign events for us to deal with. So far, it looks to stay that way for the next week at least. Although, once again, we will be looking for possible storm development out in the open central Atlantic, well north of the deep tropics which seem to be closed for repairs….

I’ll have more tomorrow.

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