Will the American West Coast Ever Be Hit by a Hurricane? [Journal of Events]

August 25, 2017:

As I've been driving into work each day this week, signs have been notifying everyone that a hurricane will probably hit southern Texas. They advise not driving in that direction. I'm sure others have seen these signs and have heard about the terrible weather headed that way. This got me thinking: Will a hurricane ever hit the west coast in the future?

Why aren't hurricanes hitting the west coast now?

The reason for this is that hurricanes generally only manifest in waters that are 80 degrees higher. States like Oregon, Washington, and California never experience this type of weather because their waters remain at 75 degrees or below. 

We all learned about this trait of severe storms in elementary school, but the recent news had me pondering, "If global warming is heating our oceans, when can we expect American west coast oceans to warm above 80 degrees and begin to produce hurricanes?"

As I was researching rates through Science Mag's AAAC, I decided to reach out to NOAA via Twitter for an answer (with a closely followed corrective tweet in my word-use).


A few hours went by with no response, so I reached out directly to former astronaut and current NOAA Adminstrator Kathryn D. Sullivan via email. Again, hours went by, which makes sense. She's an incredibly busy person. 

August 28, 2017:

It's now been a few days with no response, so I'm going to try and find the answer myself. 

Visiting NOAA's website, I found the temperatures for twelve different spots along America's western coast. (I only used areas with recent temperatures.)

I'm only using areas with the above recent temperatures for an average of 56.3 degrees. Since I'm trying to create a predictive temperature scale, I need a broader time frame. I'll continue my search.

According to a report published in Science Mag, the oceans are warming 15 times faster now than they have in the last 10,000 years. 

In its latest report, released in September, the UN’s Intergovernmental Panel on Climate Change (IPCC) noted the recent slowdown in the rate of global warming. While global temperatures rose by about one-fifth of a degree Fahrenheit per decade from the 1950s through 1990s, warming slowed to just half that rate after the record hot year of 1998. The IPCC has attributed the pause to natural climate fluctuations caused by volcanic eruptions, changes in solar intensity, and the movement of heat through the ocean. Many scientists note that 1998 was an exceptionally hot year even by modern standards, and so any average rise using it as a starting point would downplay the longer-term warming trend.
— Phys.org

So, here's what I've figured out so far:

Calculating surface temperatures probably won't give me an exact time frame, but rather just a poor guesstimate. It seems that to get an exact time frame, I would need to calculate the total energy housed in a climate system. This includes the melting of glaciers, water vapor according to a hygrometer/psychrometer, the amount of snow cover, and other climate system indicators. Let's go a different route.

I'm going to reach out to http://askascientist.co.uk/ask/ and ask the same question.

August 30, 2017:

Still no response from Ask A Scientist, so I've sent the question to NASA via their Ask-A-Geologist contact page. Hopefully they will respond. Until then, I'll be here just patiently waiting.


September 7, 2017:

Finally an answer.

After reaching out to multiple sources for an answer, I was finally contacted by Sharon Fitzgerald of the USGS who said:

Hi Eric,

I am sorry to take so long in answering your question. I hope people in Texas are recovering.

According to this article, while warming to >80 degrees F will be conducive to hurricane formation, the movement is still going to be away from the US coast.
— SF

She ended the email by sending me to an article called, "Why do hurricanes hit the East Coast of the U.S. but never the West Coast?" published on the Scientific American website. Here I found what I was looking for and found that I was halfway to the answer.

Finally, an Answer:

The original question was when will hurricanes hit the west coast in the future since waters are slowly warming. The answer comes in two parts:

1. First, it's due to colder water temperatures, which is what we found earlier on in this article.

2. Second, and the rest of the puzzle:

[...]hurricanes in the northern hemisphere form at tropical and subtropical latitudes and then tend to move toward the west-northwest. In the Atlantic, such a motion often brings the hurricane into the vicinity of the East Coast of the U.S. In the Northeast Pacific, the same west-northwest track carries hurricanes farther offshore, well away from the U.S. West Coast.
— SA: Chris W. Landsea - a researcher at the Atlantic Oceanographic and Meteorological Laboratory/Hurricane Research Division of the National Oceanic and Atmospheric Administration (NOAA)

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