2013 Weather In Review

The unlucky 13 of 2013 has passed into memory lane. Now, we are in 2014. We will not see another year with the number 13 until 2113, which is 99 years from now. I doubt I will be around that time. Anyways, 2013 was a rather interesting weather year as you can see in the top 10 2013 weather events I compiled. Let’s see how 2013 fared in rainfall and temperature by region.

2013 America
Annual Temperature: 52.40°F
Annual Rainfall: 31.16

1895-2013 Average
Temperature
Mean: 52.19°F
Median: 51.99°F
Standard Deviation: 0.91

Rainfall
Mean: 29.18
Median: 29.31
Standard Deviation: 2.16

2013 in America is rather interesting. In terms of temperature, it was within annual mean and median. However, when it comes to rainfall, it is close to being abnormally wet, but within the standard deviation. 2013 is a far cry from 2012, which was a very warm year. Here are two maps that show the difference in in temperature and rainfall by state. Dry in the West and wet in the Midwest and East. Here is a map by state.

2013RainTemperature

Even though, America was wetter than normal, the drought persists and is getting worse, especially in the Western US. It is most severe in California, where the drought is likely the worst since 1500s. The culprit is a cool Pacific Decadal Oscillation (PDO), which is the same reason why Texas is dry. A cool PDO causes the jet stream to go further north, carrying storm systems that produce rain further north, which is amplified with La Nina.

There is also a persistent ridge at 18,000 feet or 5,600 meters over the Pacific, Western Canada, and Alaska. I generated this maps and it clearly shows that. The ridging diverts storms northwards around the ridge and the storm goes southwards towards the Upper Midwest. The ridging is what deprives the Western US their rain.

2013_500mb_GeopotentialAnomaly_NorthernHemisphere

The same ridging is also causing Alaska and Western Canada to be warmer than normal. The ridging allows the air to warm, while diverting cold air to the south. Ridging over the North Pacific and Alaska is sign of a negative East Pacific Oscillation (EPO). EPO is North Pacific equivalent to North Atlantic Oscillation (NAO). A negative NAO causes ridging over Northeast Canada and Greenland, and causes cold air to go down south. Negative NAO is a strong factor in cold winters like 2009-2010.

2013_Surface_TemperatureAnomaly_NorthernHemisphere

On the topic of the effect of PDO and EPO on Texas, let’s go straight to Texas.

2013 Texas
Annual Temperature: 65.10°F
Annual Rainfall: 27.39

1895-2013 Average
Temperature
Mean: 65.11°F
Median: 65.08°F
Standard Deviation: 0.98

Rainfall
Mean: 27.93
Median: 27.43
Standard Deviation: 5.29

The 2013 temperature average and rainfall total is within the standard deviation. It is not often that happens as Texas is prone to either extreme cool or hot and dry or wet years. In fact, 2013 was a normal year in terms of temperature and rainfall.

Granted, Texas is still in a drought, but in a better shape than in 2011. However, I am a bit concerned the drought could return if we do not see more rain. On the topic of Texas, let’s head to the Upper Texas Coast.

2013 Upper Texas Coast
Annual Temperature: 69.33°F
Annual Rainfall: 44.52

1895-2013 Average
Temperature
Mean: 69.46°F
Median: 69.43°F
Standard Deviation: 0.95

Rainfall
Mean: 47.64
Median: 46.34
Standard Deviation: 10.42

Like America and Texas, Upper Texas Coast had normal temperatures despite a heat wave in late June, where Houston saw 107°F. The reason for the slightly cooler year is that Spring 2013 is one of the coolest on record. Rainfall was within standard deviation despite dry months in 2013. Some months would be dry, while other times it would be wet. If it was not for the heavy rains of April, May, and October, 2013 would have been a dry year for the Upper Texas Coast.

Even though Upper Texas Coast had near normal rainfall total and heavy rain events have happened, I am concerned about drought as we are still in a cool PDO phase, which I mentioned previously in regards to California’s drought problem. The past five years has not seen an abnormally wet year. The last time that happened was in 2007. Here is a divisional map.

2013DivisionalRainTemperature

It shows the climate divisions in the Upper Midwest had record breaking wet years, especially in the Michigan, Dakotas, and Montana. In fact, North Dakota and Michigan had their wettest year on record. Large area of California and parts of Idaho had their driest year on record. The drought in California is worse than in 1977. Many areas saw record wet and dry years in 2013 as you can see in the divisional map.

In terms of temperature, most areas were slightly cooler than normal. There are pockets of warmth, but if you want really warm years, go West. Many areas in California were warm, but not record breaking warmth. No area shattered records in temperature in 2013.

What will 2014 hold in the weather world? I think it could be an interesting one. Perhaps we could see more freezes and snow in the winter. Than tornado outbreaks in the spring. By the time hurricane seasons starts, I think we could see the first major (Category 3 or above) hurricane to make landfall, which would be the first since Wilma in 2005. Until than, time will only tell.

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