Spring 2014 Report

Spring2014Ranks

Spring has passed as we approach summer as the days get longer. So, did winter choose to remain despite the fact the calendar says spring? Some areas were still cold and ice still prevailed in the Great Lakes. It was warm in the Western US as they are still languishing in a drought.

America
Temperature: 51.13°F
Rainfall: 8.01

1895-2014 Spring Statistics
Spring Temperature Mean: 51.06°F
Spring Temperature Median: 50.82°F
Standard Deviation: 1.36

Spring Rainfall Mean: 7.93
Spring Rainfall Median: 7.91
Standard Deviation: 0.97

America as a whole had a largely normal spring because of the stark contrast in temperature and rainfall. Some regions were cooler, while others were warmer. In terms of rain, some regions got more, while others got less. So that cancels each other out. This surface temperature anomaly map shows the eastern half of the US was cooler, while western half of the US was warmer. Most of the cold air was over Canada and Upper Midwest. Most of Arctic, Asia, and Europe had warmer than normal spring.

2014SpringSurfaceTemperatureAnomaly

One wonders why was the Eastern US cooler than the Western US this past spring. Look at a 500 millibar level geopotential height to look for anomalies. A positive anomaly is persistent ridging, while negative anomaly is persistent troughing. Here is a map of the 500 millibar level geopotential height anomaly map.

2014Spring500mbGeopotentialAnomaly

The North Atlantic Oscillation (NAO) is in a positive phase, as there is persistent troughing over Greenland and Northeastern Canada. A positive NAO usually means warmer than normal winter when NAO is positive. However, there is persistent ridging over Alaska. That area is called Nort Pacific Oscillation (NPO) or East Pacific Oscillation (EPO). When there is ridging over Alaska, the NPO/EPO is negative, while troughing over Alaska means positive NPO/EPO. The NPO/EPO is similar to NAO, but over the North Pacific Ocean. A negative NPO/EPO gives America a cooler than normal winter. It can have much influence than NAO, like this past winter, which was a cold one. Another cold winter where the NAO was positive, but NPO/EPO was negative is the winter of 1983-1984. That winter was really cold, especially December 1983.

Now, let’s look at the great state of Texas’s spring.

Texas
Temperature: 64.13°F
Rainfall: 6.12

1895-2014 Spring Statistics
Spring Temperature Mean: 64.75°F
Spring Temperature Median: 64.73°F
Standard Deviation: 1.77

Spring Rainfall Mean: 7.26
Spring Rainfall Median: 7.05
Standard Deviation: 2.16

Like America, Texas had a normal spring in terms of temperature and rainfall. The temperature is below average, but within average. Texas saw normal March rainfall as it got beneficial rains to put a dent on the drought. However, Texas needs more rain to end this drought, which will hopefully be case with El Nino. So, how did Houston area fared in Spring.

Upper Texas Coast
Temperature: 66.93°F
Rainfall: 11.12

1895-2014 Spring Statistics
Spring Temperature Mean: 68.50°F
Spring Temperature Median: 68.39°F
Standard Deviation: 1.68

Spring Rainfall Mean: 10.38
Spring Rainfall Median: 9.91
Standard Deviation: 4.28

It is not your imagination that Spring 2014 was cool in Southeast Texas. It was cooler than normal despite the fact that Texas and America had normal spring. The Upper Texas Coast cracked the top 20 coolest spring on record. It is even cooler than Spring 2013. Winter prevailed in Spring 2014 for Upper Texas Coast. This is despite the fact it is within the mean, but close enough to be outside the mean to be considered abnormal. Here is the top 20 coolest spring in the Upper Texas Coast.

Top 20 Coldest Spring
1.) 1931 63.37°F
2.) 1915 64.87°F
3.) 1926 65.53°F
4.) 1913 65.63°F
5.) 1983 65.67°F
6.) 1914/1969 65.87°F
7.) 1952 65.90°F
8.) 1924/1960 66.07°F
9.) 1941 66.40°F
10.) 1947 66.53°F
11.) 1970/1993 66.57°F
12.) 1912 66.60°F
13.) 1919 66.63°F
14.) 1917 66.67°F
15.) 1932 66.77°F
16.) 1942 66.83°F
17.) 1937 66.90°F
18.) 2014 66.93°F
19.) 1928/1962 67.03°F
20.) 1930 67.07°F

Spring 2014 is the 18th coolest spring on record since 1895! Spring 2013 is 22 coolest spring on record and ties with Spring 1901 as the average was 67.13°F. Interesting to note following a cool spring, a major hurricane has made landfall on the Upper Texas Coast in these years. Here are the correlation values between Spring Temperatures (March to May) and tropical landfall on the Upper Texas Coast.

Tropical Storm
r = 0.03
p = 0.71

Hurricane
r = 0.11
p = 0.22

Major Hurricane
r = -0.21
p = 0.02

All Landfall
r = 0.00
p = 0.99

There is a significant negative correlation between cool springs and major hurricanes making landfall on the Upper Texas Coast. Cooler the spring, the more likely a major hurricane is likely to make landfall. It is significant because the p-value below 0.05. Anything above 0.05 is not significant. Four of the top 20 coolest spring had a major hurricane make landfall during the hurricane season from June to November.

Major Hurricane
1915-Galveston Hurricane of 1915 (Category 3)
1932-Freeport Hurricane (Category 4)
1941-Hurricane #2 (Category 3, Based on Reanalysis)
1983-Alicia (Category 3)

Hurricanes
1947-Hurricane 3 (Category 1)

Interesting to note that San Antonio Spurs won the NBA Championship, a hurricane made landfall. Here are the championship years for Spurs and hurricanes that made landfall.

1999-Bret
2003-Claudette
2005-Rita
2007-Humberto
2014-?

Two are Category 3 or above, while the other two are Category 1. In Humberto’s case, had it stayed over the Gulf of Mexico longer, it easily would have been a Category 3 or above hurricane. Thankfully that never happened as it made landfall east of Galveston on September 13, 2007 at 2:00 AM. Eerily, exactly one year later on that day and time, a much larger hurricane, Hurricane Ike, made landfall on the eastern part of Galveston Island.

However, none of them had an El Nino developing that year. Most were either Neutral (2003) or going into La Nina (1999, 2005, and 2007). El Nino is forecasted to develop for this year and that reduces storm formation from westerly wind shear. However, during El Nino years, storms form closer to land and increase their chance for landfall. My spring forecast for the 2014 Atlantic Hurricane Season used years that saw El Nino developing early. Looking at it this 2014 analog GIS heat map, many of them end up in the Gulf of Mexico, particularly the Central and Western Gulf of Mexico.

2014AnalogHurricaneHeatMap

Notice the highest risk for storms to hit are the Central Gulf Coast region, which is Louisiana, Mississippi, and Alabama. Southeast Texas is also in a high risk area for landfall during an analog season where El Nino is developing. It proves that even a less active season is just as dangerous as an active season.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s