Weather Extremes

While everyone's attention has been focused on the tragedy from Hurricane Harvey (more on that in a future posting), there are some other weather extremes that have been taking place.

I was talking to a friend who lives in San Francisco and she told me the temperature there was over 100 degrees. I was floored! Sure enough, the recorded temperature on September 1 was 106 degrees F. We have a word for temperatures like that in Texas - heat wave! And, we're use to temperatures over 100 degrees. How does this compare to normal San Francisco temperatures? It's the all time high temperature ever recorded there. The average high for September 1 is 70 degrees - 36 degrees cooler.

At the same time, there are wildfires raging in the west. Fires have been burning all summer and, as of September, there are dozens still burning.

This is not some cherry-picking, either. While it is true the Northwest US is experiencing widespread record high temperatures, it actually is a worldwide thing. Worldwide 2016 temperature averages were the highest ever recorded and by a wide margin, breaking the previous record, set in 2015, by .2 degrees C (.36 F). That makes 2016 the third year in a row to set a new record high average temperature. (What was that? There hasn't been any warming since when?)

The thing I find interesting is how as soon as a snowflake falls, climate change deniers are out laughing and asking 'where is global warming.' And yet, when temperature records are smashed, they remain silent. The amusing thing is that their posturing actually supports the scientific evidence. When deniers come out and say something along the lines of, 'This particular date in this particular city was the coldest day recorded in 30 years,' what they're really saying is that temperatures that used to be the norm haven't been experienced in 30 years. Why would that be?

Meanwhile, Bangladesh is suffering from the worst flooding in 40 years. Bangladesh is a country prone to severe flooding, so that statement is highly significant. The death toll in Bangladesh from this one event is estimated at 142, as of September 3. Stunningly, over 1200 people have perished in flooding in Nepal, India and Bangladesh since June.

Even without Hurricane Harvey, we see severe weather is becoming worse and worse. And now, Hurricane Irma is on the way.

War On Science

I was reading a blog post by meteorologist Dan Satterfield about the forecasts made concerning Superstorm Sandy in 2012. At the time, the European forecast model (ECMWF) had Sandy hitting New Jersey while the American model (GFS) had it going out to sea. As we all know, the Europeans were right.

Turns out, there is more to the story than just two different forecasting models. The real problem is that the Americans did not have current computers. The European computers were faster and were able to make more detailed forecasts. It turns out, when the GFS is given the same detailed information the ECMWF had it produces similar results.

This means the problem wasn't the model. The problem was the funding. Given proper funding, the American's would have had the ability to make an accurate forecast in advance the same way the Europeans did. You now have to wonder how much damage and how many deaths were caused because of the disconnect between the two. If both ECMWF and GFS had provided a forecast showing Sandy striking New Jersey what would have been done differently?

Satterfield, states it well,

The anti-science posture of many of our so-called political leaders is actually having an impact on many aspects of how science is done in this country. The effects are widespread, and run from NASA, to weather prediction, to a serious deficiency in weather satellites. While NOAA now has new computers going online, we’re going to have a tough time catching up, because Europe,China and Japan are not sitting still. More so, they aren’t sitting around arguing over stickers in Biology books saying that natural selection is just a theory, or fighting over teaching accurate climate science to high school students. The result is that they have better weather models, faster computers and much more sophisticated weather satellites that can feed data into those models.

Missing Hurricanes Not Evidence Against Climate Change

Climate change deniers typically pull out the same false arguments over and over again. I don't believe I've heard a truly original claim in several years. Take a look at the submissions to the Global Warming Skeptic Challenge to see what I mean. That is one of the reasons I was so confident about putting up my own money. Based on what I have seen I knew my money was safe.

One of these recurring claims they make to 'prove' manmade global warming isn't real is the fact there has been a lack of hurricanes striking the U.S. It has been since 2005 that the U.S. was hit by a major hurricane - beating out 1861-1868 as the longest period in history without a major strike. This is a false argument for a number of reasons. For instance, we're discussing 'global' warming, not U.S. East Coast warming. Plus, when you look at the worldwide history of tropical cyclones the record shows the level has remained the same for the last 20 years. However, the energy released by all storms combined has apparently increased by as much as 70% over the last 35 years. 

Now, a new study indicates even the current drought of U.S. landfalls is just a random chance - nothing more.  The researchers used the historical data to calculate how often a nine-year drought in U.S. landfalls would occur and they determined it is once in 177 years. It has been 147 years since the last major drought, so the current situation falls well within the realm of statistical probability.

The results suggest that there is nothing unusual underlying the current hurricane drought. There’s no extraordinary lack of hurricane activity, for example.

“When we looked qualitatively at the nine-year drought, they aren’t inactive seasons,” said Hall. There has been no significant change in the number of North Atlantic tropical cyclones, the amounts of energy powering them, nor any other hurricane metric.

I would say the deniers will have to revise their claim, but I already know the scientific evidence doesn't matter to them so it is highly unlikely they will change. In fact, my guess is would occur only once in 177 years, but that is within the realm of probability.

Tropical Storms in the Southwest

The remnants of Hurricane Norbert hit the Southwestern U.S. this week and caused havoc. Record rainfall in the region caused flooding, closed roads and led to at least two deaths. To really add injury to injury, the flooding is not likely to help with the drought. The system missed the areas hardest hit by the drought and didn't help at all. Even in areas that got rain, the rain came so hard and fast that it ran off rather than soak in. Some, of course, will be caught in the reservoirs and will provide some help, but most will lost.

A tropical storm system hitting this region is very unusual. Just look at the fact that it was not only the single day record rain, but it really shattered the old record. Norbert dumped 3.29 inches on Phoenix on Monday. The old single day record was 2.91 inches and was 81-years old. The new record is more than 13% higher than the old one. (There was also a 4.98 inch rainfall in 1911 that occurred over two days, but within a 24-hour period, making it the 24-hour record holder.) What isn't revealed in that statistic is that the 3.29 inches fell in just seven hours. You don't see this kind of record history very often in places that get tropical storms on a regular basis.

According to Wikipedia, there have been four tropical storms that have hit the Southwester U.S. with gale force winds since 1900. Norbert was not the fifth. Storm organization had degraded quickly when the storm hit Mexico and wind speeds dropped precipitously.

So, why do so few storms hit this region? After all, there are lots of Pacific storms that form in this region and tropical cyclones in the Northern Hemisphere tend to hook towards the Northeast. You would think this would create a situation conducive for West Coast storm strikes.

The answer lies in the ocean temperature. The California Current along the West Coast originates in the north and moves southwards along the continental margin.  Take a look at this plot from Climate Reanalyzer showing the ocean temperature for September 11, 2014:

Source: Climate Reanalyzer

The light blue band along the coast line clearly shows how the waters in this region are cooler than ocean waters farther out to sea (to the left, or west). There are two things that are needed for tropical cyclone development: warm ocean water and a lack of high-altitude wind shear. As it turns out, the California Current not only cools the water, it also leads to high-altitude wind shear. Storms that form and move into this region run right into a hurricane killer. The U.S. West Coast has it very own hurricane-barrier.

But, what is going to happen as the ocean gets warmer as a result of climate change? We don't need to speculate, we can look at the record and we can see what is already happening.


While Norbert didn't bring gale force winds, it did fall in the category of tropical storm remnant affecting the Southwest. Again, according to Wikipedia (not a research quality source, but adequate for our purpose here), there have been 67 storms (not including Norbert) that are recorded to have had an impact on California.

Number of recorded storms impacting California

Period	Number of storms
Pre-1930	11
1930s	7
1940s	3
1950s	5
1960s	3
1970s	7
1980s	9
1990s	7
2000s	10
2010s	5

Adding Norbert, this list indicates that there have been 39 of the 68 storms since the beginning of the 1970s, over 57% of all of the storms on this list. Why did I use that time span? Take a look at this graph for the answer:

Source: NOAA

This graph shows the ocean temperature started a significant increase in the late-1960s. Remember, tropical storms need warm water. We would expect, if all things remain equal (a bad assumption, but a good starting point) that the California hurricane barrier would start to break down and that is what the data seems to be indicating.

Take a look at this plot, also from Climate Reanalyzer:

Source: Climate Reanalyzer

This plot shows the temperature anomaly for September 11, 2014, the same day as the other ocean temperature plot. The difference between the two is the first plot showed the actual water temperature and this one shows the difference between the actual temperature and the average temperature. Just as the above plot clearly showed the California Current to provide cooler waters along the West Coast, this one shows, equally clearly, that the waters along the West Coast are getting warmer. Quite a bit so, in fact.

Does this mean California and the Southwest can expect more tropical storm remnants? I believe the data shows that is already happening. Does this mean there is a possible relief for the long-term drought? Again, I believe the data already shows this is not the case. Droughts are relieved, and caused, by long-term changes in the precipitation pattern. Flash floods with large amounts of runoff are not going to provide the relief needed. That will take long, soaking rains and heavy snowfall in the mountains. In fact, there is evidence the warming oceans is what is actually causing the drought.

The conclusion I reach from this is that this region is already experiencing severe effects from global warming and will continue to see them into the future.

Global Warming and Tropical Cyclones

Tropical cyclones (hurricanes, typhoons and cyclones) get their energy from warm ocean water. As water vapor rises and condenses into liquid water it releases very large amounts of energy, which powers the storm. So, it is a natural assumption that as the oceans heat up, we should see some resulting effect in the formation of tropical cyclones. But, it isn't that easy. There are more factors in the formation of cyclones than just ocean temperature. Wind shear, in particular, is critical for the formation of cyclones. As a tropical depression starts to form, too much wind shear will blow the energy from condensing water away and will also deform the shape of the central vortex which makes up the eye of the storm, making it less likely a storm will form. Of course, global warming will have an effect on wind shear. And, there are other factors involved in storm formation, as well. So, we can't just say that as the sea surface temperature goes up we will see more and stronger storms.

But, what will happen is an important question and one that a lot of research is being done on. A paper published by scientists at Stony Brook University and MIT, appearing in the Journal of Advances in Modeling of Earth Systems described some recent computer model results. The authors modeled an idealized tropical climate and used cloud formation models to develop tropical cyclones on a supercomputer. As they varied the sea surface temperature from 21 degrees Celsius (70 degrees F) to 36 degrees Celsius (97 degrees F), they found that the size and strength of the cyclone increased as the temperature went up. At the same time, fewer storms were formed. A 6 degree Celsius (11 degree F) rise in temperature resulted in a doubling of kinetic energy in each storm as well as a doubling in the amount of precipitation.

How valid is the model? In fact, we have already seen these results taking place over the last 50 years.

Based on this computer model and the actual storm events over recent decades, what we can expect as global warming continues is fewer storms, but the ones that form will have stronger winds and more rain. Damage from storm surges will increase dramatically due to a combined effect of larger storm surges and rising sea levels.

Of course, guess who will get to pay for all of this damage? Hint: It won't be the fossil fuel industry.