Remnants of Bill still alive and well, tropics as a whole quiet for now

Tropical depression Bill as seen via visible satellite photo on June 20, 2015

Tropical depression Bill as seen via visible satellite photo on June 20, 2015

Tropical storm Bill made landfall early Tuesday morning along the central Texas coast and has since left a tremendous amount of rain in its wake. Fortunately, the flooding situation in Texas was not as severe as it could have been but in parts of Oklahoma, it’s a different story.

Bill once again underscores the importance of the public having a grasp on the total package, so to speak, that tropical cyclones bring. It’s not just categories of hurricanes or the amount of storm surge, rain and the resulting freshwater flooding has a way of sneaking in and seemingly catching people off guard.

Today, the remnant low pressure area of Bill is currently moving through parts of Arkansas and Missouri. Heavy rain is falling in areas such as St. Louis and will spread up the I-70 corridor in to Indiana over the weekend. The satellite presentation is still rather impressive for a depression that has been over land for several days. The low is forecast to track through Kentucky and eventually off the Mid-Atlantic states within the next few days, spreading more heavy rain along its path.

As for the tropics going in to the weekend – nothing to worry about at all. We are currently within a period of time that is not likely to allow for much development in either the east Pacific or the Atlantic. This should last for about 10 to 15 days, maybe more, we’ll see. In addition, dry, dusty air from Africa is traversing the Atlantic right now, keeping a literal lid on any development chances out that way. So enjoy the weekend along the shores, tropical storms and hurricanes won’t be an issue anywhere. I’ll have more here on Monday.

M. Sudduth 1pm ET June 20

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Blanca forecast to make landfall along Baja, moisture to spread in to U.S. Southwest

Forecaast map for hurricane Blanca in the east Pacific

Forecaast map for hurricane Blanca in the east Pacific

Hurricane Blanca is on track to make landfall along the Baja peninsula late this weekend or by early Monday. Fortunately, the wind will not be as much of an issue as the rain will be since Blanca will be moving over cooler water before landfall.

Right now, top winds are 100 mph which is substantially weaker than we saw a couple of days ago when the hurricane peaked at category five intensity. The irony of that incredible strength is that it ultimately doomed the hurricane. Why? Upwelling. Because the steering currents were very weak, Blanca, with its intense winds, sat over almost the same geographic area of the ocean for at least a day. This churned the Pacific significantly underneath the hurricane causing cold water from below to be mixed in to the surface. The result – a much weakened hurricane.

While Blanca has diminished from its record-setting power, it is still a formidable hurricane which will bring wind, rain and rough seas to portions of the Baja this weekend and in to early next week. People in the region need to be ready and not regard a weaker hurricane as less of a threat to life and property. Torrential rain alone can be a big problem.

Speaking of rain, moisture from now dead hurricane Andres and eventually from Blanca will stream northward in to the Desert Southwest of the U.S. This will increase the chance of heavy rain for some areas but not likely as widespread as we saw with Norrbert and Odile last season. In any case, interests in the Southwest U.S. should keep tabs on their local forecast over the next several days as the situation unfolds. High mountain snowmelt combined with any potential heavy rain events will easily cause streams, creeks and dry washes to reach flood stage quickly.

In other news, I am en-route to Houston for the hurricane workshop tomorrow at the George R. Brown Center. I am looking forward to interacting with literally hundreds of people as they stop by to see the HurricaneTrack Tahoe and some of our newest equipment used to study hurricanes at landfall.

After the workshop, it is time to head northwest to Amarillo. Monday is an exciting day. We test launch HURRB as we prepare for the 2015 season ourselves. I will have a separate, more thorough blog post on what we are doing with that tomorrow evening or on Sunday. Until then, keep an eye on Blanca if you live along the Baja peninsula. The Atlantic Basin is nice and quiet now so no worries there for the weekend ahead.

M. Sudduth 12:00 PM ET June 5

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Hurricane Blanca likely a problem for Baja then Southwest U.S.

Hurricane Blanca in the east Pacific

Hurricane Blanca in the east Pacific

It’s like 2014 all over again in the east Pacific. Hurricane after hurricane developing over the abnormally warm water in the region. The latest, Blanca, poses a risk to the Baja peninsula and eventually parts of the Southwest United States.

The latest from the NHC indicates that winds are near 110 mph. The forecast suggests that Blanca will become significantly stronger as it moves roughly parallel to the Mexican coastline. Fortunately, the hurricane is far enough off shore to spare the mainland any direct impacts. However, in a few days, the southern tip of the Baja is probably going to have to deal with this system.

Most model guidance and the official track forecast from the NHC suggest that Blanca will turn slightly more to the east with time as the high pressure area over the east Pacific breaks down due to a trough of low pressure off the California coast. This will allow the hurricane to track right in to the Baja region this weekend.

The intensity forecast brings Blanca close to category five due to very warm ocean water and an ideal upper level pattern. In fact, the hurricane is going through a steady period of rapid intensification right now which should last for another day or so. This means at the very least, tremendous swells will begin to impact the coast ahead of the hurricane itself due to the intense winds over the open ocean.

How strong Blanca is once it encounters land along the southern Baja remains to be seen. Water temps cool off along the forecast track close to the peninsula. Also, the NHC mentions upper level winds becoming less favorable with time, inducing shear over the hurricane. All of these factors should result in a weaker system at landfall. No matter, interests in the region should prepare for a hurricane and its associated effects by this weekend.

Once Blanca makes landfall and interacts with the Baja it will decay very quickly. However, the moisture plume that will stream northward from the dying hurricane will inevitably dump heavy rain over parts of southwest Mexico and the southwest United States. Right now, this does not look to be as serious a situation as we saw unfold last year with Pacific hurricanes Norbert and Odile. Moisture will be on the increase across the Southwest by early next week but it is too soon to know just how much and precisely where at this point. The forecast will be refined in the coming days and much will depend on how strong Blanca remains after landfall.

In other news, I am heading out beginning today for a trip to Houston, Texas for the annual Ready or Not Houston/Galveston Hurricane Workshop this Saturday. It is probably the largest event of its kind in the country and is well worth the time of anyone who stops in for a visit. Numerous agencies, news media, hurricane experts and relief organizations participate in order to bring the public exceptional hurricane information and preparedness info.

I will have the HurricaneTrack Chevy Tahoe on display along with several pieces of brand new equipment that we have developed for observing hurricanes up close and personal using technology. I will also have our HURRB (Hurricane Research Balloon) payload to show off as well. In fact, after the workshop wraps up Saturday, the team and I head up to Amarillo to prepare for a test launch of HURRB on Monday morning.

Our goal is to have a successful launch and recovery of the payload via high-altitude weather balloon. The on-board weather computer will store air pressure, temperature and humidity data every two seconds for the entire mission. If all goes as planned, the payload will ascend to at least 100,000 feet above Earth before the balloon bursts due to extreme low pressure. HURRB will then fall back to the ground via parachute to be retrieved by our team using satellite and ground based tracking. We’ll get to see it all from the point of view of two GoPro cameras mounted on the outside of the payload.

I will stream the entire trip out to Texas and back live on our public Ustream channel. On Monday, bright and early at that, I will also have the HURRB test streaming live as well. It’s all part of our own preparedness activities for the season ahead, no matter what it brings. Despite the forecast for fewer than average hurricanes, we need to be ready just as you do for that one landfall possibility that could change everything. If you live close enough to Houston to make it worth your while, I invite you to come out to the George R. Brown center on Saturday. Stop by the Tahoe and say hello. It’s an important event and we are proud to support it by our participation. No one knows for sure what kind of season we will end up having, being ready makes sense, no matter the numbers being forecast.

I’ll have more from the road including blog posts concerning Blanca and its projected impact on the Baja and the Southwest U.S.

M. Sudduth 9:35 AM ET June 3

 

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Pre-June development more of an interesting feature than anything serious

Latest sea surface temps off the Southeast coast. The red circle indicates the area of likely development of the low pressure area this week. Note that SSTs are just warm enough, 26C, in a narrow area north of the Bahamas

Latest sea surface temps off the Southeast coast. The red circle indicates the area of likely development of the low pressure area this week. Note that SSTs are just warm enough, 26C, in a narrow area north of the Bahamas

Here we are again just a few weeks out from the Atlantic hurricane season beginning and we have something to watch in the waters off the Southeast coast.

The National Hurricane Center has outlined an area of interest associated with a remnant frontal system that has managed to park itself over fairly warm water (for this time of year). The atmosphere and ocean could work together to spawn a semi-tropical storm system later this week. Before anyone gets too worked up about it, let’s look at some facts.

First of all, it is May. We typically don’t see much tropical or sub-tropical activity during the month of May. However, of all the off-season months that we do get development, May is the most active. In fact, it is active enough, around two dozen or so developments over the past 100+ years, that I am not sure why the hurricane season doesn’t officially begin in May. That’s a story for another day perhaps.

This time of year, water temperatures are warming but are not typically warm enough to allow for the deep moisture content needed to support a tropical storm or hurricane. On the other hand, the southwest Atlantic is running a bit above normal right now with the 26C line (79.5F) extending northward out of the Bahamas just off the Southeast coast. This region of marginal water temp threshold is narrow and limited. It is surrounded by much cooler water temps, mid-70s or so. This gives us reason to believe that what ever tries to develop will have very limited conditions to work with.

The other aspect of this potential development, as noted in the NHC’s Tropical Weather Outlook (actually they issued a special version of it since it’s not officially hurricane season yet), is that the low pressure area that is forecast to develop is non-tropical in origin. This means it lacks the true deep warm-core structure that we see in say a tropical wave origin storm or hurricane. Take Gonzalo last October, its birth can be traced back to a tropical wave, full of heat and moisture, that emerged from Africa. The low pressure that is likely to spin up off the Southeast coast will come from a non-tropical environment off of an old frontal boundary. While this is often an excellent genesis point for tropical storms and hurricanes to grow from, it usually takes longer for them to acquire full tropical characteristics. This simply means that we are likely going to see a very shallow, limited convection based storm system develop by mid-week.

As far as impacts go, a storm over the ocean is always a concern for boaters and beach interests. An increase in swells, rough surf and winds along the coast from northern Florida up through the Carolinas is likely later in the week. Think of it as a kind of hybrid storm, not fully what we would look for during the height of the hurricane season. Thus, the bottom line here is that while it’s possible we’ll have something interesting to talk about this week, the effects will be confined to the coast and just inland and shouldn’t amount to more than passing rain showers, breezy conditions and rough surf.

One note about this: the North Carolina Outer Banks took quite a beating from a departing ocean storm late last week. Some beaches sustained heavy erosion and can ill-afford any additional aggravation right now. Hopefully this potential storm system will not meander far enough north to rough up the area any more than has already taken place. That being said, interests along the Outer Banks in the usual flood prone areas should pay close attention to what happens with this low pressure area. It’s been a rough few years, dating back to Irene in 2011. Since then, storm after storm has lashed the region and even weak systems add more to the problem.

I’ll have more here on this developing system throughout the week ahead. I’ll also be posting a video blog to our app, Hurricane Impact, as well as to our partner app, Hurricane Pro and HD, later today. It’s that time of year again, well, almost anyway…

M. Sudduth 9:10 AM ET May 4

 

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El Niño not likely to be a factor for 2015 Atlantic hurricane season

Even though it is January, there are clues that we can look for when trying to figure out how busy the upcoming Atlantic hurricane season may be. One of those clues is the state of the El Niño.

As we know, El Niño or the abnormal warming of the tropical Pacific, tends to suppress Atlantic hurricane activity due to a number of factors. For a good deal of 2014, it looked as though a rather substantial El Niño event was going to unfold – it failed to do so. However, the tropical Pacific did warm quite a bit and in fact, most of the warmest water on the globe was found in the Pacific during last year’s hurricane season. This is a big reason why the east Pacific was so very busy and the Atlantic was not.

As of early January, the tropical Pacific was only slightly warmer than usual with a noticeable decline in sea surface temperatures in the east Pacific, just west of Central America. In fact, as far as I can tell, we are not even in an official El Niño right now as the thresholds have not been met. This is not surprising if we look at some other aspects of a traditional El Niño event.

One of those aspects is the SOI or Southern Oscillation Index. Typically the more negative it is, the more likely we are to see El Niño conditions prevail in the atmosphere AND in the oceans. What’s the trend over the past 90 days been? A slow and steady rise in the SOI. As the chart shows, October was -8.2, November was -8.0 and December was -7.6 with the current daily value showing +4.4. What does this mean? In short, it means that the pressure pattern is such that the trade winds are not all that weak across the tropical Pacific and thus the El Niño is being held back if not stopped completely.

Latest SOI chart from the Australian BOM

Latest SOI chart from the Australian BOM (click to view full size)

More evidence of the collapse of the El Niño can be seen via the temperature depth anomaly chart from the Climate Prediction Center. This shows us what the temperature profile is of the tropical Pacific from the surface down several hundred meters. Clearly you can see the loss of the warm pool as the animation progresses over the past several weeks. In fact, cooler anomalies are showing up in the eastern Pacific at a depth of around 110-150 meters. Unless more warm water begins to migrate eastward (from left to right on the chart) then the warming of the tropical Pacific will be very slow if not stopped entirely.

Equatorial Pacific Temperature Depth Anomaly Animation

Equatorial Pacific Temperature Depth Anomaly Animation (click to view full size)

So what does this all mean as far as impact on the 2015 hurricane season? While it’s too early to be confident about the demise of the El Niño, the most recent forecasts indicate that the odds of neutral conditions are beginning to outweigh El Niño as we get in to the Atlantic hurricane season which begins in June. This is very important because a cooler tropical Pacific would likely mean less upward motion in that region compared to what we saw in 2014 and this could lead to a better chance for Atlantic development, even if only a little. Remember, 2014 was not too far off from being an average season and so any increase in activity this year would seem to most people as being quite busy, especially considering how slack things have appeared to be since 2012.

Early January 2015 forecast for ENSO state - notice how the green (neutral) outweighs the red (El Nino) beginning as soon as the Feb/Mar/April time frame

Early January 2015 forecast for ENSO state – notice how the green (neutral) outweighs the red (El Nino) beginning as soon as the Feb/Mar/April time frame (click for full size image)

There are many other factors to consider as we enter the 2015 Atlantic hurricane season but the state of the ENSO is a big one and thus far, it appears that it will not be much of a negative influence. Obviously, the climate models can and do make gross miscalculations and we could end up with a raging warm episode by late summer. However, with other signals leaning in the direction of a non-El Nino event shaping up, I tend to think that the forecast will be pretty accurate and that we will not have an El Nino during the 2015 hurricane season. We shall see…

I will post an update to this information in early April, right before the National Tropical Weather Conference which is being held in South Padre Island again this year. By then, we’ll be within 90 days of the hurricane season getting started. I’ll have other topics posted before April of course but that’s the next logical time to take a look at the ENSO state again. Until next time, stay warm!

M. Sudduth 9:26 AM ET Jan 14

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