Tropical

Dean strengthening, TD5 in Gulf

Good morning!

TS Dean has maintained its intensity of 45 knots overnight. Satellites from around 0900Z indicate that Dean is trying to wrap convection around an “eye”-like structure, which may in time develop into a true eye. The system has taken on the classic recognizable “comma” shape of a tropical cyclone, and in the face of low shear, should develop into a symmetrical and photogenic hurricane. Dean is in very low shear now, having escaped the 20kt that limited its intensification previously. This is good for development. However, since it’s happening during the day, Dean’s ability to utilize this may be limited. We’ll have to see.

NHC’s forecast has taken a westward shift, in line with what the computers are indicating. As I said in my previous blogs, I am on board with a Caribbean –> Gulf storm and do not intend to change this prediction unless the ridge is eroded too much for it to happen.

The GFDL and HWRF, our two tropical cyclone-specific models, are both in unfortunate agreement in their 00Z runs of taking Dean to a borderline Cat 3/Cat 4 in the central Caribbean and sending it south of Hispaniola. If this pans out, there is a chance that he will enter the Gulf as a Cat 3 or Cat 4 without ever having hit a large landmass.

I’m not happy about this. In such a scenario, we’d have to hope for shear towards landfall, because the very hottest Gulf waters are right offshore.

Closer to home, TD5 has formed in the Gulf, although according to the NHC it seems to have some problems getting together. Well, it’s a new system. That’s what usually happens. Quite honestly, in my opinion, TD5 could landfall in Texas as anything from a depression to (if conditions are perfect and it takes advantage) a low-end Category 1 hurricane. The NHC is forecasting a 40kt landfall. I think that, if TD5 gets organized in time, it has the potential for rapid development, and this forecast could be too low. With the depression, everything comes down to the timing of its organizing.

Tropical

Dean holds steady

Tropical Storm Dean has held its intensity in the face of a small pocket of 20kt shear. Although its convection dropped off significantly during the diurnal minimum, this is cyclical, especially for a weak system. Dean used the day to do something more important than blowing up blobs of clouds, start developing the classic tropical cyclone structure. It has feeder bands forming, and as soon as it gets out of the pocket of shear, I’m expecting it to take off. The timing on this is important: If it breaks into the minimal shear area to its west at night (night for it, a few hours ahead of people in the Americas), the effect will be more pronounced in a short time. This is because of diurnal max. Dean is skipping along a tad south of due west at 20 mph.

I think it’s now fair to start discussing where Dean will end up and how strong he will be. I highly doubt that he will recurve, and I am not sold on a U.S. East Coast landfall either (including Florida’s east side). In the short term, I think it’s fair to say that Dean will be a weather-maker for the islands off Venezuela. I also have a bad feeling that he will get into the Caribbean. The water there is even hotter than in the Gulf. A major hurricane seems highly likely if this happens. Many people in the U.S. see a powerful hurricane hit Hispaniola, and see the mountains tear it up and weaken it (a good example is Georges of 1998), so that it has a hard time restrengthening before its final landfall, and they cheer. But the island nations can’t afford a hit any more than New Orleans can. The 12:00 run of the HWRF showed a Hurricane Allen-like system barreling headlong into the Dominican Republic at peak intensity. Needless to say, this would be horrific. The one good thing about Dean is that, since it’s a long-track Cape Verde storm, there’s plenty of time to watch it, and prepare for landfall.

Beyond the Caribbean, as I have stated, I have a really bad suspicion that this is ultimately a Gulf problem. I’m not going to change this guess until and unless the real, observed weather conditions change as Dean continues on its path and gets closer to the point where it must “decide” whether to curve out of the Caribbean or not. Fluctuations of models, which have had it from Central America to an Atlantic fish storm, don’t qualify. Real, large-scale changes in weather do.

The NHC, which has a tendency to underforecast the intensity of hurricanes, has Dean as a 95kt Category Two system in five days. Again, how quickly Dean gets its act together will determine when (NOT “if”) it becomes a hurricane and thus when it may hit Cat-2 or higher intensity. It has followed the NHC’s predicted intensity forecast thus far, and tropical storms usually take several advisories to get fully “with it” and reach a level of stability that permits them to develop eyes and become hurricanes. I see no reason to deviate significantly from the NHC forecast, with the one caveat that Dean might rapidly intensify after it becomes a hurricane.

Note: If anyone tries to tell you that Dean, or any other new TS, has an eye at any intensity under about 55 kt, they don’t know what they are looking at. Former hurricanes that made landfall, of course, are a different matter, and the eye structure could persist long after it lost hurricane-force winds. But newly-formed storms don’t start to develop eyes until they approach hurricane intensity.

Tropical

Flossie and proto-Dean

Against all predictions, Hurricane Flossie in the Central Pacific exploded to a Category 4 and is posing a threat to Hawai’i, although it is expected to weaken and avoid a direct hit on the islands. It seems to the casual observer that the EPac has had all the activity this year. It might prompt the question, does the advent of Flossie signal a change in the ENSO pattern?

NO!

While it is true that, usually, the most intense hurricanes and typhoons in the Pacific basin occur during El Ni

Tropical

TD4, 91L, and Flossie

As expected, former invest.90L strengthened in to Tropical Depression 4 this morning. The system is currently embedded in moderate shear. This has caused the depression to be elongated, as the satellite images show. It will keep it from becoming very strong for now. At a brisk pace of 20 mph, it should move out of this shear in a day or two, and we can then expect explosive intensification. I expect this system to become a hurricane by Thursday night. As for where it will go from there — I don’t know, neither do you, and neither do the computers!

A system in the north Caribbean/southern Gulf of Mexico is intensifying its convection. Shear is low in the area. It’s possible this may form into something, but I’m not expecting it.

Hurricane Flossie in the Pacific is starting to appear a little more ragged in its satellite, hopefully signaling the long-expected weakening. However, because it was a Category Four for so long, it has built up a large surge, which will threaten Hawaii in the form of waves as the hurricane approaches the islands.

Tropical

The race to be Chantal

Well, the month of July didn’t pass without a tropical cyclone forming! Former invest 98L was declared Tropical Depression 3 tonight by the NHC. I think they may have missed the boat on this and in reanalysis, the storm could well be analyzed as having formed earlier (as a subtropical depression that transitioned into a full TD today). It may well get the name Chantal before the Central Atlantic disturbance 99L, but if so, it won’t last long as a tropical system. The system is also not forecast to be strong at sea. The only threat is to Europe as an extratropical cyclone.

Closer to home, invest 99L has formed from a central Atlantic tropical wave, and is heading WNW into the Caribbean. It is fairly strong for a tropical wave, and is developing outflow, as one can see from the satellite picture — especially to the north. After having much of its convection sheared off today, it is rebuilding itself. More importantly, the new convection is forming directly over the surface low, as opposed to the earlier convection, which was lopsided and was hindering further organization. This is a MAJOR leg up for 99L. If this continues, I suspect it will be named TD Four by tomorrow afternoon, perhaps even late morning. The real question is whether this system or TD 3 will get the C name.

The DSHIPS intensity model forecasts it to become a hurricane within 3-4 days.

As some may know, I don’t treat any computer model as a deity, because I think that they all miss things. And so it is with this model for this storm. I don’t quite buy this forecast of intensity. I do think the storm will develop, and will probably eventually become our first hurricane of the season, and will unfortunately threaten the Gulf and Caribbean, but not that soon. There is a fair amount of dry air in its path, and shear, while favorable, isn’t ideal — 10-15 knots in some spots.

Anyway, this is definitely a system to keep an eye on if you live anywhere from Central America to Florida. (Wide range, I know, but it’s pretty far out!) Like clockwork, we move from July into August, and it looks like the Atlantic is transitioning as well.

Climate change

Bad Air.

This is a bit of a rant.

The Massachusetts Bay area is under an Air Quality Alert and Air Stagnation Advisory today. Particle pollution and ozone levels are expected to be at level orange, “unhealthy for sensitive groups.” Here is the text of the National Weather Service message:

AN AIR QUALITY HEALTH ADVISORY HAS BEEN ISSUED BECAUSE OZONE AND PARTICLE POLLUTION LEVELS ARE EXPECTED TO CONTINUE TO BE ELEVATED ALONG THE COAST AND INTERIOR REGIONS ON WEDNESDAY. THE MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION RECOMMENDS THAT INDIVIDUALS CONSIDER LIMITING STRENUOUS OUTDOOR PHYSICAL ACTIVITY TO REDUCE THE RISK OF ADVERSE HEALTH EFFECTS. PEOPLE WHO MAY BE ESPECIALLY SENSITIVE TO THE EFFECTS OF ELEVATED LEVELS OF POLLUTANTS INCLUDE THE VERY YOUNG...AND THOSE WITH PRE-EXISTING RESPIRATORY PROBLEMS SUCH AS ASTHMA AND OR HEART DISEASE. THOSE WITH SYMPTOMS SHOULD CONSIDER CONSULTING THEIR PERSONAL PHYSICIAN.

Symptoms, all right — try “difficulty breathing,” “the urge to faint,” “fatigue,” “coughing fits,” and “respiratory chest pain.”

While the ozone apparently hasn’t kicked in yet as of 2:00 p.m. local time, the particle pollution is VERY evident already. Apparently I am in a “sensitive group.” OK, I am — I’m mildly asthmatic. This happened last year, when ozone and particle pollution days were quite frequent in July and August during the East Coast heat waves.

This form of pollution is caused by hot temperatures such as what we’re having today (approaching 100 degrees), a persistent haze, and people with polluting habits. Taking the thoroughfares into one of the cities during peak hour generally means that your car crawls along at 25-40 mph and often has to stop altogether. This sort of driving pattern just contributes extra to the pollution level, especially when the vehicles are in close quarters, as they would be during peak hours.

Look, the area has public transit. Most commuter rail stops are within a reasonable driving distance of someone’s home. For most people, it really isn’t necessary to do a 2 hour commute on the freeways. (If there truly aren’t any other choices for you, I’m not complaining about you.) I don’t ask that you alter your schedule every day, but is it really too much to ask for commuters to forgo the car for a couple of days out of the month in the summer, out of consideration for people with respiratory problems that are aggravated by the pollution?

The big stumbling block in doing something about global warming, which incidentally is always the stumbling block for any sort of environmental change, is that people don’t want to change their habits. They certainly don’t want to make sacrifices if they don’t see their behaviors directly affecting themselves.

I’m in the prime of my life, but among those who experience ill effects on these high pollution days, I’m in the minority in that respect. Most people who have problems are either elderly or children. You wouldn’t blow car exhaust into your elderly parent’s face, or your kid’s. But by choosing to drive on days when the air pollution potential is high, you might as well be doing just that.

Forecasting

Record heat in the Northeast on Friday?

It’s not yet astronomical summer solstice, but tomorrow is effectively the first day of summer for New England and the Mid-Atlantic. With highs forecast to approach 95 degrees in Boston and Providence, 89 in New York, and 91 in Hartford, CT, the Northeast is apparently going to be the second-hottest region of the country on Friday, behind the desert Southwest.

With a persistent high pressure centered on the East Coast, Friday also looks to be sunny. Wear your sun block! This applies to people driving into the area for Memorial Day weekend, too — in the absence of tinted glass, sunlight can and will shine through your car’s window and cause sunburn! I know this from personal experience.

The lack of moisture in the air during peak heat hours will likely reduce the heat index and lower the risk of heatstroke, but it will raise the risk of dehydration. Anyone traveling to the area for Memorial Day weekend should remember to bring LOTS of water with them, in case they have vehicle problems or run into traffic jams and have no air conditioning. This is the first time since last year that this sort of heat was recorded in the Northeast area.

Forecast for Boston: High 94, UV index of 10, low humidity (~18-20% at peak heat)

Forecast for New York: High 89, UV index of 10, low humidity (~25% at peak heat)

Forecast for Bangor, ME: High 92, UV index of 10, low humidity (~17% at peak heat)

This type of weather is going to be the story everywhere in the region. Hot, sunny, and dry. Stay lathered up with sunscreen if you are exposed to sunlight, and stay hydrated!

Climate change

Global Warming Would Drown the Coastal Hurricane Defenses

The barrier islands of the Gulf Coast are an important defense against hurricanes. Mostly uninhabited, they are the first landforms that a Gulf Coast hurricane strikes. While they do not weaken the hurricanes (they aren’t large enough), the islands take the brunt of the hurricane’s storm surge, diffusing it somewhat before the eye makes landfall on the mainland. They are also an important defense against tsunami, a real (if little-known) threat. Significant seismic activity has occurred in the Gulf of Mexico fairly recently.

Global warming is predicted to melt part of Greenland and/or West Antarctica, raising sea levels worldwide up to 20 feet (more if all of Greenland and some of West Antarctica melted). This would have horrific consequences on coastal cities around the globe, of course. This blog, however, will focus on one specific area — the United States Gulf Coast. (Ha, doesn’t it always?)

If global warming raised sea levels as predicted, most of low-lying Louisiana — as well as the critical barrier islands — would be underwater. The low-lying swampland of Louisiana, which has been receding for years now, is another natural barrier for the coast, as well as an environmental treasure. It too would be covered in water.

The coastline would lose its natural defenses against hurricanes.

And, as research is indicating, global warming would also intensify the hurricanes themselves.
The EPA produced a series of pictures showing the coastal areas that are most at risk from global warming-induced inundation. Red indicates areas that are less than 1.5 meters above sea level. The images can be clicked on to show a larger view.

Here is an image of Louisiana and Texas:

And here’s one of Mississippi, Alabama, and Florida:

It’s hard to see on these maps, but the barrier islands are the thin trail of red south of the main coastline. They would be underwater.

More disturbingly, from the National Environmental Trust, here is a QuickTime movie of how Biloxi, MS (and its barrier island) would be affected by a rise in sea level. (WARNING for dial-up users: 3 MB file!) I’ve linked to the movie from this graphic I’ve made showing how the coastline would be inundated.

The barrier island protecting the city would no longer exist. Sure, the projection of the land would still exist underwater, and would serve to slightly lessen the impact of a storm surge, but it isn’t at all the same as having a true island above the sea. A dry, projecting landmass stops the flow of water, at least temporarily, and breaks the waves. A former island that has gone underwater obviously doesn’t keep the water from flowing.

Also, as you can clearly see, the city itself would be partially underwater. This includes the glitzy new development that is taking place on this part of the coast in response to Hurricane Katrina — very shortsightedly, I ought to add. Whether this is because of the government of Haley Barbour, who is very likely a global warming skeptic, or because the businesses are aware of the risk but decided to hedge their bets, I do not know.

The Katrina recovery and rebuilding process is not taking global warming into account at all. When the next really bad hurricane strikes, its impact could be compounded by the effects of global warming. The coast will be farther inland due to rising waters, there will be fewer natural barriers, and the hurricane itself is likely to be stronger and wetter than it would be without global warming. And, as unfortunate as it is for me to say this, at this point it’s not enough to simply drive less, replace incandescent light bulbs with fluorescent, cross our fingers, and hope that we’ve stopped the problem.

I absolutely support cutting carbon emissions. If we don’t, the consequences will be even more horrendous than the scientists are daring to predict right now. But we’ve reached a point where it would be nothing short of grossly irresponsible to fail to look into preparation for the potentially disastrous changes that we have brought upon ourselves.

Climate change

Global Warming and Methane Under Pressure

When I first watched An Inconvenient Truth, I went to the special features on the DVD and watched the follow-up interview with Al Gore. He spoke about recent research about global warming that had come out since the shooting of the film, such as information about a link between hurricane intensity and global warming. But far more disturbing than that was a discussion of how global warming could cause the tundra to thaw enough to release methane and carbon dioxide into the atmosphere, further compounding the problem.

Think of it as twisting the cap too fast on a soda bottle that has been shaken. After that seal is broken, the carbon dioxide in the bottle rapidly bubbles up, and nothing can stop the inevitable horrid mess. You just want to get out of the way of it.

Obviously, that’s not an option for us if the permafrost thaws.

But I wanted to see for myself. Gore’s interview didn’t go into great detail about what might happen if this occurred, and I wanted to see just what the ramifications of it could be.
This article from the Energy Bulletin was written in late 2004, so the science isn’t brand-new by any means. But the article was far more horrifying than Gore’s interview:

A temperature increase of merely a few degrees would cause these gases to volatilize and “burp” into the atmosphere, which would further raise temperatures, which would release yet more methane, heating the Earth and seas further, and so on. There’s 400 gigatons of methane locked in the frozen arctic tundra – enough to start this chain reaction – and the kind of warming the Arctic Council predicts is sufficient to melt the clathrates and release these greenhouse gases into the atmosphere.

Once triggered, this cycle could result in runaway global warming the likes of which even the most pessimistic doomsayers aren’t talking about.

An apocalyptic fantasy concocted by hysterical environmentalists? Unfortunately, no. Strong geologic evidence suggests something similar has happened at least twice before.

The most recent of these catastrophes occurred about 55 million years ago in what geologists call the Paleocene-Eocene Thermal Maximum (PETM), when methane burps caused rapid warming and massive die-offs, disrupting the climate for more than 100,000 years.

The granddaddy of these catastrophes occurred 251 million years ago, at the end of the Permian period, when a series of methane burps came close to wiping out all life on Earth.

Uh, what?

The great Permian extinction was nothing new to me. Although less famous among the non-geologist non-paleontologist set than the Cretaceous extinction that killed the dinosaurs, anyone who’s ever read many National Geographics knows about this event. And I knew it was probably triggered by a rapid change in climate. However… methane releases causing it? I had to see if this was based in fact.

Well, it appears that it was.

The Wikipedia article on the Permian-Triassic extinction offers a list of explanations for it, along with descriptions of the likelihood and evidence for each. Here they are:

  • Continental drift: When the continents joined into one massive landmass, this affected the oceans, causing extinction of some marine life. However, it’s considered insufficient to account for close to 95% of life on Earth dying.
  • Impact of a celestial body: An asteroid, meteor, or comet may have struck Earth, as happened at the end of the Cretaceous era. There is no direct evidence of this, though, and apparently everything claimed as evidence has fallen into serious question.
  • Supernova: A star could have supernova’d relatively close to the solar system, causing radiation that would wipe of most of the life on the planet. It’s possible, but there is no astronomical evidence that one occurred.
  • A spike in volcanic activity, causing global warming that disrupted the climate system, shut off oceanic currents, deprived the ocean of oxygen, and triggered the release of methane trapped in the sea. That Energy Bulletin article says that methane is far stronger than carbon dioxide as a greenhouse gas, and it would have caused an additional 5 degrees Celsius rise in temperature on top of what the volcanism-induced global warming had already caused. What’s more, there is considerable geological evidence to support this theory, as compared with the rest of the extinction theories. It’s all in the article, and it would amount to quoting the entire piece if I put the relevant parts here. It’s there; read it for yourself and be freaked out just as I was.

Of course, nothing like that could happen again.

Right?

…

Well, realistically, that probably is a doomsday scenario. It’s only happened once in the entire history of life on Earth, although there was another pretty bad event that took place in the Cenozoic Era. However, the central theory behind the foreign and domestic security policy of the United States has been to prepare for the most minuscule possibility of a worst-case scenario. Ron Suskind wrote a book about this idea called The One Percent Doctrine. I don’t know about you, but — without any intention of minimizing terrorist activity — as far as I’m concerned, the mass extinction of most life on Earth is a bit larger of a potential problem than a terrorist attack. If ever there’s an appropriate use of “the one percent doctrine,” it would be to prevent a mass extinction.

In Al Gore’s interview about this problem, he says that “it’s not a good thing” when methane is released into the atmosphere. I would nominate that for understatement of the year.

Climate change, Oscillations

The New, Improved, Super-charged El Niño

Also, African Rain Moves Westward?

UPDATED, 1/10/2007:
2006 was the warmest year on record, it was reported today, ahead of the previous title holder, 1998. 1998 was influenced heavily by the El Niño that began in 1997. And, sure enough, scientists have concluded that this year’s Niño was, effectively, super-charged by global warming. From the right-leaning Chicago Tribune:

In 1998, record high temperatures were driven by an unusually powerful El Nino current that disrupted weather patterns worldwide. The current El Nino, a periodic warming current that took shape last summer, is far weaker and has had only a moderate effect on global climate, several experts said.

“What we are seeing is much more than El Nino,” said climate analyst Kevin Trenberth at the National Center for Atmospheric Research in Boulder, Colo. “The overall pattern is consistent with our concepts of global warming.”

The original blog entry:
Part 1: El Niño 2006-07: Overachiever or Cheat?

As most people are aware, an El Niño formed in autumn of 2006 and has continued to this date. This event was basically single-handedly responsible for cutting off the 2006 hurricane season at the knees. El Niños do that — the last time we had one, it developed in late autumn of 2004 and ended a two-month streak of damaging hurricanes. And that one wasn’t even very strong. It was weak enough, in fact, that most articles in the popular press that talk about this year’s event don’t even refer to 2004; they say that the last El Niño was in 2002. The one this year is a moderate Niño.

This NOAA site shows the Oceanic Nino Index, an indicator of the temperature departure from the average for various three-month periods, going back to 1950. Positive values indicate El Niño-like conditions and negative values indicate La Niña. The site isn’t updated to reflect the new values, but they have increased past the levels of the 2004 Niño event.

The bottom line, though, is that this year’s event is not even close to the strength of the notorious 1997-1998 event. It is moderate. Mild.

Yet, during the most recent period of warmth for the Eastern United States, heat records were set in numerous eastern cities. The most common date for the old records?

Yep, 1997. There was a winter “heat wave” during the same time period during that year’s Niño as well. Continue reading The New, Improved, Super-charged El Niño →