Rush for National Hurricane Center to name storms?

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An excellent article over at the Houston Chronicle on the NHC’s recent rush to name storms.

… a controversy is brewing over decisions of the National Hurricane Center to designate several borderline systems as tropical storms.

Some meteorologists, including former hurricane center director Neil Frank, say as many as six of this year’s 14 named tropical systems might have failed in earlier decades to earn “named storm” status.
…such information is vital to scientists trying to determine whether global warming has had a measurable impact on hurricane activity.

Hurricane Humberto

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Looking back at Hurricane Humberto, it is notable that Hurricane Humberto developed from a tropical depression into a category 1 hurricane in less than 18 hours. Quite a feat. Even within hours of our previous post the satellite pictures were looking quite impressive and radar too.

Tropical Depressions 8 and 9

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Tropical Depression 8 formed today well out in the Atlantic at 11am according to the National Hurricane Center. TD 8 was looking good on the satellite last evening so this comes as no surprise. TD 9 also formed in the Gulf of Mexico and Tropical Storm warnings are up for parts of Texas.

Likewise, no one should be surprised if we have Tropical Storm Humberto and/or Ingrid by later today or tomorrow.

Any bets on whether TD 9 will be Ingrid or Humberto?

Our best guess is the TD 9 will be Humberto and TD 8 will be Ingrid. [Turned out to be the way it happend. ]While TD 8 looks more impressive on the satellite, an Air Force aircraft will be investigating TD 9 sooner than TD 8 and given its proximity to Texas, it will likely be named first. [As time showed, Humberto’s overall organization improved very quickly after this post.]

Hurricane Dean is now a Major Hurricane

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After watching Hurricane Dean all week, Hurricane Dean has strengthened significantly today. As of the 11pm advisory Dean has 145 mph winds and a 937mb central pressure. Models and the NHC forecast continued strengthening over the next 24 hours. No matter how you slice it an extremely dangerous storm.

Currently the model consensus has Dean passing directly over Jamaica. Several things should be noted. If the eye of Hurricane Dean does pass directly over Jamaica, the high elevations of Jamaica should disrupt the storm significantly. Simiarly, if the eye passes near enough to Jamaica the mountainous terrain will likewise disrupt Dean, the question is how much of an impact the mountains will have.

All that said, it will be interesting to see how accurate the models are. Given that we are still around 40 hours away from a potential Jamaica impact, much can changed based on the speed that Dean continues to move westward. Dean’s westward speed will determine how much various features (e.g. the high over the SE US right now) move Hurricane Dean around. A slowing Dean (now 18 mph speed) will probably lead to a more southerly track whereas a faster moving Dean would lead to a more northerly track the farther out you go.

Up to 72 hours models are generally pretty accurate (some exceptions such as Hurricane Erin in 1995 when bad data was entered) so take precautions now. For more than 48 hours, everyone from Florida, through the Gulf Coast down to Central America should watch this storm and be prepared to take action as directed by local authorities. As you can see (as of 11pm, August 17, 2007), the NHC has a large area still in the 5% Tropical Storm Force Wind Speed Probabilities.

Preparation is key.

It is June 30th 2007, where are all the Hurricanes?

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As June 2007 comes to an end let’s take stock to see where the season stands. So far the Atlantic Basin has had 2 tropical storms – Andrea and Barry with Chantal to be next. Seems like a pretty quiet season so far, doesn’t it?

To see where we stand, let’s recall some other record breaking years, starting with 2005 which as we all know was a record-breaking season. If you had to guess, how many storms had formed by the end of June 2005? Well? 5? 7? By June 30, 2005, there had been a total of 2 storms – Arlene and Bret. It wasn’t until July 5 that we had both Tropical Storm Cindy and Dennis. We had Emily on July 11th and then Franklin on July 22. Gert arrived on July 23. So, we had 2 storms through the end of June in 2005 and 7 storms by the end of July 2005.

The second busiest season was 1933 had one storm form in May and one storm form in June. Just like 2007. July ended with five storms and the season ended with 21 storms. 1934 also had one May storm and one June storm, and three storms by the end of July, again just like 2007. It ended with 11 storms. So a record breaking season, and a below average season both had the same number of storms by the end of June.

Now, looking at 2004, another season that was memorable. By the end of June 2004 we already had 0 storms. Zero? Seriously? Yes. Alex didn’t arrive until July 31st. But by the end of August 2004 though, we had already had Hermine. 2004 was memorable not for the shear number of storms, but for the places they hit.

Some other seasons:
2002: 1 by the end of July, season ended with Lili.
2003: By June 30th, we had had Ana (April 20-24) and Bill (June 29-July 02) and we ended up the season with Peter.
2004: Zero storms by the end of June and 1 on July 31st. Ended with Otto.
2005: 2 storms by the end of June and ended with Zeta.
2006: 1 storm by the end of June, 3 by the end of July, ended with Isaac.

(Interesting note, in 1981, Arlene formed on May 6-May 9 and Bret from June 29-July 1, so the season was similar to 2007 so far and 1981 ended with 12 storms including a subtropical storm in November).

So what does it mean that there have “only” been two storms by the end of June, 2007? Absolutely nothing in our view. Busy seasons like 2005 and 1933 have had a June like this, while more quiet seasons like 1981 and 1934 have had similar Junes.

In fact, there are only 13 known seasons (as of 2007) since 1851 that have had 2 tropical storms form in June. June 2007 has only had one storm form during the month, but one in May.

The Chicken Littles would have you think that the Junes of 2005, 2006, and 2007 should be significantly worse than the Junes of 1933 and 1934 given we’ve had nearly 75 years of carbon emissions. Perhaps the link isn’t quite as strong as some people want to believe? Remember that it only takes one storm – see Andrew, the first storm of the season in 1992 hitting Miami – to have a devastating and memorable season. Preparation is key whether we have one storm or ten storms.

Will 2007 be a busy season? We’ll let you know in November 2007, but it is difficult to predict the rest of the season based on the season up through June.

Global Cooling and Sun spots

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A nice article on the current state of climate research, and the impact that the sun and sun spots have on climate. With all the talk about Hurricanes and global warming, it is critical that the information and debate be based in reality.

The article includes this quotation:

Climate stability has never been a feature of planet Earth. The only constant about climate is change; it changes continually and, at times, quite rapidly. Many times in the past, temperatures were far higher than today, and occasionally, temperatures were colder. As recently as 6,000 years ago, it was about 3C warmer than now. Ten thousand years ago, while the world was coming out of the thou-sand-year-long “Younger Dryas” cold episode, temperatures rose as much as 6C in a decade — 100 times faster than the past century’s 0.6C warming that has so upset environmentalists.

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Key Hurricane Satellite Could Fail

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A key hurricane satellite, called QuikSCAT, could fail at anytime according to the NOAA’s Administrator Conrad Lautenbacher. Launched June 19 of 1999 ( with a 2-3 year mission life, the satellite is 5-6 years past its projected life span and running on a backup transmitter. Seguir leyendo »

2007 Hurricane and Tropical Storm Forecasts

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Most of the well-known forecasters have weighed in with their 2007 forecasts now, so let’s take a look at what is being predicted.

• NHC/NOAA Hurricane forecast summary:
13 to 17 tropical storms
7 to 10 of them becoming hurricanes.
75% chance of above normal hurricane activity according to the NOAA’s NHC.

Other people are predicting:
• William Gray from Colorado State predicts 17 named storms with 9 hurricanes.
• AccuWeather calls for 13-14 tropical storms with 9 becoming hurricanes.
• Tropical Storm Risk (back in March) expected to bring 17 tropical storms, of which nine will strengthen into hurricanes.

Essentially all within the same ball-park.

What does this MEAN? It means that the experts think that we’ll have a busy season – we may or we may not, see below. So what should you do now? You have two choices: prepare now and be ready if a hurricane hits your area or don’t prepare and have no options. Preparation is a pretty simple matter when you have time to prepare, so the smart choice is to be ready.

In our view, these forecasts are an educated guess based on statistical analysis of previous seasons as applied to current seasons’ weather patterns. There is currently no magic box (or even sophisticated computer program) that can provide an accurate forecast for the number of storms. That said, the annual predictions are a worthwhile exercise in order to advance our knowledge. Studying current weather patterns, comparing these patterns with previous years, and then attempting to forecast based on the intersection between the two advances our knowledge incrementally and advancing knowledge is very worthwhile.

When the actual number of storms falls near the long term average, the forecasts are general correct since the forecasters generally end up predicting trends near the average while adjusting for various well known factors. The way forecasting works (usually) is you start with a long term average as your prediction and then you adjust it up or down based on various factors. For example, El Nino or La Nina’s presence or lack thereof will cause forecasters to adjust their predictions up or down. Patterns over the Atlantic, dust or lack of dust from Africa work similarly. Sea surface temperatures impact the forecasts also. It is merely a matter of how much each factor will impact storm formation and whether the impact will be up or down.

Let’s recall previous year predictions compared with the actually events. Please remember, the forecasters do their best with the knowledge they have.

2006 ended with 10 named storms (one between Alberto and Beryl that was unnamed during the season and only identified in the post-season analysis).
CSU had predicted 17 storms
AccuWeather: 6 tropical cyclones (3 major) will strike US coast (none did), with a total number “above average”
NHC/NOAA predicted:
* 13-16 named storms (hurricanes and tropical storms)
* 8-10 of which will become hurricanes
* 4-6 of which will be major hurricanes (category 3 or higher)

In summary, the number of storms was well below predictions.

Actual: 28 tropical storms, 15 hurricanes, 7 major
CSU’s May forecast, predicted 13 named storms for 2005, which was obviously well off.
NOAA: 12-15 Storms, 7-9 hurricanes, 3-5 of them major

In short, the number of storms greatly exceeded pre-season predictions.

Actual: 15 storms, 9 hurricanes, 6 major
NOAA: 12-15 Storms, 6-8 hurricanes, 2-4 major
CSU: 14 storms, 8 hurricanes, 3 major (May 2004 forecast)

The number of storms in 2004 fell in the average range and consequently pre-season predictions were quite accurate, only fall well below actual numbers in the “major storms” category.

Hurricane Katrina final report

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The Final report from the National Hurricane Center on Hurricane Katrina has been issued.

The highlights on Hurricane Katrina are as follows:

1. Hurricane Katrina was a category three (3) storm when it made its closest approach to New Orleans, although it had been a category five (5) storm previously.

2. “The strongest winds corresponding to that [Category 3] intensity were likely present only over water to the east of the eye.” This means that the category 3 winds were well east of New Orleans.

3. “The sustained winds over all of metropolitan New Orleans and Lake Pontchartrain likely remained weaker than Category 3 strength.” New Orleans was experiencing a Category 2 hurricane. A majority of the damage was due to flooding, not winds. Flooding was caused by political failures in terms of 40-50 years of neglect and political games.

4. Surge was signficant and pentrated miles inland along bays and rivers. In some cases up to 12 miles inland. It was worse east of the eye, but still significant to the west of the eye – e.g. in the New Orleans area.

The facts on Katrina and Wilma should illustrate several important points that must be remembered.

a. Storm strength can change quickly. In 24 hours Hurricane Wilma went from a small tropical storm to the most powerful hurricane (measured by low central pressure) ever measured in the Atlantic Basin (to that point). Likewise Hurricane Katrina strengthened rapidly.

b. There is no such thing as “only a Category 1 or 2” hurricane – let alone “only category 3.” When both Hurricane Wilma and Hurricane Katrina made landfall neither was a Category 4 or 5 storm and New Orleans only experienced Category 2 force winds. In both cases the damage was significant. Much damage was due to neglect of flood control systems over 40 years due to political neglect and political game playing.

In short, there is no such thing as a minor hurricane. Evacuation is always your safest option – get out of the path of the storm. Following hurricane preparation guidelines – for water, food, yard etc. Too often we hear people blaming others for their own failure to prepare. Your own safety is your own responsibility first. Simple steps will help you to ensure that you do remain safe, but they do require planning.

Likewise, when the City, State, and Federal governments are assuring you that levees (or buildings or any structure) can survive a category 3 (or higher) storm do not always believe them. The National Hurricane Center will provide extremely accurate facts and information. However, politicians will use that information for their own political gain – look at the Hurricane Katrina hearings and the finger pointing in Hurricane Katrina’s aftermath. Politicians who are quick to assign blame to anyone they can in order to cover themselves are people to whom you should not look to for advice. They’ll take credit when they can, and deflect blame for everything else. No one who behaves that way is a leader, they are a disgrace.

Christian H F Riley

You can read the entire Hurricane Katrina report on the web. Hurricane Katrina Report

You can read the entire Hurricane Wilma report on the web.

A great satellite image of Katrina