2013-2014 Winter

Winter2014Ranks

BRRRRRRR!!!!!!!!! It was a cold and snowy winter for many. For some, they ask, “Where is winter?” as it felt like that winter never came. This winter has been certainly cold compared to recent winters of 2011-2012 and 2012-2013. So, how cold was this winter?

America
Temperature: 31.27°F
Rainfall: 5.69

1895-2014 Winter Statistics
Winter Temperature Mean: 32.29°F
Winter Temperature Median: 32.47°F
Standard Deviation: 2.01

Winter Rainfall Mean: 6.74
Winter Rainfall Median: 6.69
Standard Deviation: 0.89

It has been quite cold for America. A far cry from last two winters, which were balmy. Winter did not want to come. So, why was this past winter cold? The reason is the North Pacific Oscillation (NPO) or East Pacific Oscillation (EPO). Like North Atlantic Oscillation (NAO) and Arctic Oscillation (AO), when EPO goes negative, it causes upper level ridging over Alaska, which allows cold air to go down south. Even if EPO is negative, while NAO and AO are positive, America gets cold. This setup happened in December 1983 and February 1989, where deep freezes hit America.

2013-2014Winter500mbGeopotentialAnomaly

Winter rainfall has been below average. This is mainly due to the dry winter in the Western US. So, how does 2013-2014 rank? Let’s look at top 20 coldest winter since 1895.

Top 20 Coldest Winter
1.) 1978-1979 26.61°F
2.) 1894-1895 26.65°F*
3.) 1935-1936 27.78°F
4.) 1898-1899 27.95°F
5.) 1909-1910 28.17°F
6.) 1904-1905 28.69°F
7.) 1928-1929 28.72°F
8.) 1977-1978 29.04°F
9.) 1916-1917 29.10°F
10.) 1917-1918 29.11°F
11.) 1911-1912 29.35°F
12.) 1903-1904 29.89°F
13.) 1976-1977 30.01°F
14.) 1902-1903 30.03°F
15.) 1948-1949 30.14°F
16.) 1936-1937 30.35°F
17.) 1914-1915 30.39°F
18.) 1963-1964 30.40°F
19.) 1983-1984 30.56°F
20.) 1919-1920/1984-1985 30.57°F

*December 1894 data is missing.

Notice there have been some data change for climate division, so the value and ranking is a little different. For example, Winter 2009-2010 was 15th coldest winter on record and now it is 22nd coldest on record. Winter 2013-2014 does not make the top 20 list. It is the 34th coldest winter on record. It is cold considering that last winter was 19th warmest winter on record. Quite a stark contrast right there. Interesting to note that some of the coldest winter occurred in the same decade, 1910s and 1970s and some occurred back to back in the early 1900s, mid to late 1910s, and late 1970s.

Since, this winter had been dry, how does 2013-2014 fare in the rainfall department. Here is a top 10 driest winter on record.

Top 10 Driest Winter
1.) 1976-1077 4.17
2.) 1930-1931 4.68
3.) 1980-1981 4.72
4.) 1894-1895 4.73*
5.) 1962-1963 4.88
6.) 1946-1947 5.40
7.) 1963-1964 5.47
8.) 1919-1920 5.63
9.) 1903-1904 5.68
10.) 2001-2002/2013-2014 5.69

*December 1894 data is missing.

I got the winter rainfall forecast way off. 2013-2014 is the 10th driest on record and ties with 2001-2002, which had little snow on the East Coast. That lack of snow contributed to the clean up of what used to be the World Trade Center, which tragically was destroyed on September 11, 2001 by terrorists. Initially, it was feared that it could take up to two years to clear the World Trade Center site. The dry winter is due to the severe drought in the Western US, especially in California. If I was in California, I would be more worried about drought than earthquakes. At least earthquakes happen quickly, while droughts are prolonged. Also, droughts can happen anywhere in the world, whether desert or tropical rainforest. A huge earthquake can only happen in areas with active fault lines, which is Pacific Rim or South Asia due to India subcontinent moving further north.

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

Texas
Temperature: 45.93°F
Rainfall: 2.42

1895-2014 Winter Statistics
Winter Temperature Mean: 47.28°F
Winter Temperature Median: 47.22°F
Standard Deviation: 2.32

Winter Rainfall Mean: 4.82
Winter Rainfall Median: 1.83
Standard Deviation: 4.68

It was even cold in the Lone Star State. The cold weather may have kept things dry as it is below standard deviation as I will look soon. It makes an abnormally dry winter. That is concerning as drought is a major problem in Texas. So, how does 2013-2014 rank in Texas?

Top 20 Coldest Winter
1.) 1898-1899 41.33°F
2.) 1894-1895 41.55°F*
3.) 1904-1905 42.20°F
4.) 1978-1979 42.83°F
5.) 1977-1978 42.87°F
6.) 1963-1964 43.03°F
7.) 1911-1912 43.43°F
8.) 1983-1984 43.50°F
9.) 1972-1973/2009-2010 43.83°F
10.) 1909-1910 44.23°F
11.) 1917-1918 44.30°F
12.) 1976-1977 44.50°F
13.) 1935-1936 44.53°F
14.) 1962-1963 44.57°F
15.) 1912-1913 44.63°F
16.) 1960-1961 44.67°F
17.) 1914-1915 44.80°F
18.) 1928-1929 44.87°F
19.) 1905-1906 44.90°F
20.) 1947-1948 44.93°F

*December 1894 data is missing.

This winter is not in the top 20 coldest winter as it ranks 27th coldest on record for Texas. It makes the top 30 coldest winter on record. It is the coldest winter since 2009-2010 and that winter was cold. On the topic of rainfall, it was bone dry. That is a very concerning as Texas has been in a drought since 2008. So, how does 2013-2014 compare in the rainfall deparment?

Top 10 Driest Winter
1.) 2008-2009 1.54
2.) 1908-1909 1.67
3.) 1917-1918 1.72
4.) 1970-1971 1.80
5.) 1916-1917 2.11
6.) 1966-1967 2.12
7.) 1975-1976 2.13
8.) 1995-1996 2.31
9.) 1901-1902 2.32
10.) 2013-2014 2.42

The 2013-2014 Winter is tenth driest on record. The most recent dry winter is also the driest on record, 2008-2009. This past winter is even drier than 2010-2011 and that was a strong La Nina. This past winter was Neutral bordering into La Nina. It shows that El Nino or La Nina is not only factor for winter rainfall and temperature. There are other factors in play. In the meantime, let’s check out the Upper Texas Coast, which Houston is in.

Upper Texas Coast
Temperature: 52.17°F
Rainfall: 4.36

1895-2014 Winter Statistics
Winter Temperature Mean: 53.96°F
Winter Temperature Median: 53.98°F
Standard Deviation: 2.64

Winter Rainfall Mean: 10.24
Winter Rainfall Median: 9.88
Standard Deviation: 3.54

Top 20 Coldest Winter
1.) 1894-1895 47.85°F*
2.) 1977-1978 48.07°F
3.) 1898-1899 48.90°F
4.) 1963-1964 49.03°F
5.) 1904-1905 49.17°F
6.) 1976-1977 49.60°F
7.) 2009-2010 49.67°F
8.) 1978-1979 49.87°F
9.) 1962-1963 50.03°F
10.) 1983-1984 50.07°F
11.) 1911-1912/1972-1973 50.13°F
12.) 1939-1940 50.33°F
13.) 1935-1936 50.50°F
14.) 1905-1906 50.63°F
15.) 1909-1910 50.93°F
16.) 1917-1918 51.13°F
17.) 1967-1968 51.20°F
18.) 1959-1960 51.30°F
19.) 1947-1948/1960-1961 51.37°F
20.) 1958-1959 51.43°F

*December 1894 data is missing.

Like America and Texas, the Upper Texas Coast did not crack top 20 coldest winter. It is the 26th coldest winter on record. It is cold for sure, much colder than the past two winters. 2009-2010 was much colder than 2013-2014 despite more freezing temperatures than in 2009-2010. 2009-2010 had below average temperatures every single day. Winter 2009-2010 still remains in the top 10 coldest winter on record.

The past few months had below normal temperature. In terms of rainfall, it has been dry. The analog precipitation forecast was way off for Upper Texas Coast. The winter rainfall total is well below standard deviation of 3.54. That is very concerning as drought remains a problem. However, I was right in regards of winter precipitation as Houston saw five freezing rain events. Here is how 2013-2014 compared for Upper Texas Coast.

Top 10 Driest Winter
1.) 2008-2009 2.83
2.) 1917-1918 3.93
3.) 1970-1971 4.05
4.) 2013-2014 4.36
5.) 1908-1909 4.48
6.) 1961-1962 4.97
7.) 1896-1897 5.30
8.) 1975-1976 5.63
9.) 1903-1904 5.74
10.) 1985-1986 5.77

The 2013-2014 Winter is fourth driest on record. For the record, the Winter of 2008-2009 is driest on record since 1895. Driest winters occur usually during a La Nina and we were Neutral. This is very concerning as drought has stricken a good portion of Texas and America. However, I see light at the end of the tunnel. El Nino is developing and word is it could be a strong one like 1982-1983 or 1997-1998. If that is the case, we could see a wet spring or summer and certainly a wet fall and winter. That would be a good thing as it can bring the drought to a screeching halt.

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Spring 2013

If you thought spring was cooler than normal for the most part, you are right. Well, the exception would be the Western US, which was warmer than normal. Just last spring, it was very warm, warmest on record. That spring felt like summer came very early. This spring felt like an extension of winter.

Here is a map of temperature anomaly comparing Spring 2012 to 2013. Spring 2012 shows abnormally warm temperatures over a large portion of the US, especially over the Lower 48. Spring 2013 shows abnormally cool temperature from Alaska, Midwest, and South. Looks like all that cold air came from the Arctic.
2012-2013SpringTemperatureCompared

Here is a precipitation and temperature map ranking map. In terms of rainfall, the Midwest saw unusually wet spring. Many areas in the Midwest had their wettest spring on record. Iowa had their wettest spring on record. Spring 2013 was quite cool, especially east of the Rocky Mountain. In fact some areas had their coolest spring on record, mainly in the South and Midwest. For them, it felt like an extended winter. So, how did Spring 2013 stack up?
Spring2013Ranks

Let’s start with America from the Division Data. It was very cool throughout America, especially east of the Rocky Mountain.

America
Spring 2013
Temperature: 50.45°F
Rainfall: 7.92

Here is the spring norms for America.
Normal Spring 1895-2013
Temperature: 51.99°F
Rainfall: 7.70

Spring was below normal and below the standard deviation of 1.35. Spring in America was much cooler than normal. Quite the opposite from last spring, which was the warmest on record. So, how cool was Spring 2013 in America? Let’s look at the ranking.

Top 20 Coolest Spring For America
1.) 1917 47.45°F
2.) 1924 48.46°F
3.) 1975 48.68°F
4.) 1920 48.77°F
5.) 1950 48.97°F
6.) 1912 48.99°F
7.) 1909 49.10°F
8.) 1983 49.16°F
9.) 1960 49.19°F
10.) 1923 49.22°F
11.) 1899 49.29°F
12.) 1965 49.36°F
13.) 1971 49.43°F
14.) 1906 49.48°F
15.) 1951 49.65°F
16.) 1907 49.66°F
17.) 1970 49.69°F
18.) 1932 49.79°F
19.) 1944 49.85°F
20.) 1947 49.89°F

Spring 2013 did not make the top 20 coolest spring as it rank 38th coolest on record for America. Still cooler than normal, especially compared from last spring. It shows how much of a difference a year makes. Last spring, America wondered what happened to spring, let alone winter. 2012 could be seen as one long summer.

Rainfall was within normal. At least it is putting a dent on the severe drought, especially in the Midwest.

So, how did the Lone Star State fair for Spring 2013.

Texas
Spring 2013
Temperature: 64.20°F
Rainfall: 5.15

Here is the spring norms for Texas.
Normal Spring 1895-2013
Temperature: 65.06°F
Rainfall: 5.15

Top 20 Coolest Spring For Texas
1.) 1931 60.13°F
2.) 1915 61.47°F
3.) 1926 61.97°F
4.) 1924/1958 62.00°F
5.) 1969 62.3°F
6.) 1983 62.43°F
7.) 1987 62.7°F
8.) 1941/1947 62.77°F
9.) 1970 62.87°F
10.) 1914 63.07°F
11.) 1968/1993 63.2°F
12.) 1997 63.23°F
13.) 1973 63.27°F
14.) 1957 63.30°F
15.) 1952/1960 63.33°F
16.) 1912 63.40°F
17.) 1913/1919 63.43°F
18.) 1903/1906 63.47°F
19.) 1932 63.50°F
20.) 1917/1980 63.63°F

Spring 2013 did not make the top 20 coolest spring for Texas. Spring 2013 was the 38th coolest spring on record for Texas. Like America, a year makes a huge difference from last spring from being very warm to a much cooler spring.

Upper Texas Coast
Spring 2013
Temperature: 67.07°F
Rainfall: 9.30

Here is the spring norms for Upper Texas Coast.
Normal Spring 1895-2013
Temperature: 69.17°F
Rainfall: 10.66

This spring had temperature that were 2.1°F below normal. That is the main highlight. The standard deviation for spring temperature is 1.6°F. It is clearly a cooler than normal spring. So, how does Spring 2013 compare to past spring in terms of temperature?

Top 20 Coolest Spring For Upper Texas Coast
1.) 1931 63.80°F
2.) 1915 65.90°F
3.) 1926 65.97°F
4.) 1983 66.13°F
5.) 1969 66.57°F
6.) 1952 66.93°F
7.) 1993 66.97°F
8.) 1924/1960 67.03°F
9.) 2013 67.07°F
10.) 1937/1970 67.13°F
11.) 1932 67.17°F
12.) 1941 67.20°F
13.) 1913 67.23°F
14.) 1914 67.30°F
15.) 1901 67.40°F
16.) 1947 67.43°F
17.) 1980 67.67°F
18.) 1903 67.73°F
19.) 1988 67.77°F
20.) 1906 67.80°F

It is the ninth coolest spring on record! Yes, you read it right. Like the rest of America, Upper Texas Coast had one of the warmest spring on record in 2012. This past spring is one of the coolest on record. Weird, isn’t it? The last time Upper Texas Coast had spring that cool was in 1993.

So, why was it cool this spring? There was upper level ridging over Greenland. It causes the jet stream to go further south than usual. This allows cold air from the Arctic to march down south. March 2013 had one of the most negative Arctic Oscillation (AO). It is on top of a negative North Atlantic Oscillation (NAO). There is also ridging off the West Coast of America. Like the ridging over Greenland, it causes the jet stream to go further south than normal and allow cold air to rush in. The areas under the ridging are warmer than normal. Basically, the cool and warm air have to go somewhere. Ridging means warmer and drier, while trough means cooler and wetter.
2013Spring500mbGeopotentialHeight_JetStream

Here is what gets interesting, of the top 20 coolest springs in Upper Texas Coast, I notice a tropical system made landfall later that year. The years with top 20 coolest springs saw a tropical cyclone make landfall are:
1915
1932
1941
1947
1960
1970
1980
1983

Some of them saw major hurricanes (Category +3) make landfall, like in 1915, 1932, 1941, and 1983. In fact, I ran a correlation between Upper Texas Coast spring temperatures and tropical cyclone landfall. Here is the result.

Tropical Storm
r = -0.03
p = 0.71

Hurricane
r = 0.10
p = 0.26

Major Hurricane
r = -0.21
p = 0.02

Total Tropical Cyclone Landfall
r = -0.05
p = 0.58

There was no correlation between spring temperature and tropical storm landfall. There is some correlation between spring temperature and hurricane landfall, when the temperature is warmer. However, the p-value is not below 0.05. Now, correlation between spring temperature and major hurricane is significant as p-value is below 0.05. The correlation is negative, which means the cooler the spring, more likely to see major hurricane make landfall.

Keep in mind that correlation does not equate with causation, but interesting to note there is. Major hurricanes rarely make landfall on Upper Texas Coast as they make landfall about every 10 years on average. The closest was Hurricane Rita in 2005, but that affected East Texas and Southwest Louisiana. However, with an active hurricane season being forecasted, it increases the probability that a tropical system including a major hurricane could make landfall anywhere. It includes the Upper Texas Coast. As I say, it only takes one to make a season very devastating. Just ask the people who were affected by Alicia, Andrew, and Sandy.

Drought Misery Index

With the ongoing drought, I came up with the Drought Misery Index (DMI), which is similar to the Misery Index for the economy. Here is the formula for Drought Misery Index.

Palmer Drought Severity Index (PDSI) + Precipitation (PCP) = Drought Misery Index

Example:
-8.00 + 1 = -7.00

The more negative the DMI, the worse the drought is. Here is the current DMI, based on September outcome.

America
-2.78
-4.78 (PDSI) + 2.00 (PCP)
Lowest: -6.01 August 1934
Highest: +9.91 May 1983

Texas
-2.49
-3.78 (PDSI) + 1.29 (PCP)
Lowest: -7.22 September 1956
Highest: +15.51 October 1919

Upper Texas Coast
0.38
-2.05 (PDSI) + 2.43 (PCP)
Lowest: -4.64 July 1925
Highest: +20.98 October 1949

All data is from the Division Data and it can change as more data is put in and averaged out.

2012-2013 Winter Report Progress Report

Winter2013Ranks

Meteorological Winter of 2012-2013 has passed into memory lane. Time flies fast as Christmas felt like yesterday and it is almost Easter. So, how did Winter 2012-2013 stack up?

America
Temperature: 34.36°F
Rainfall: 7.10

1895-2013 Winter Statistics
Winter Temperature Mean: 33.01°F
Standard Deviation: 1.99

Winter Rainfall Mean: 6.43
Standard Deviation: 0.88

America had the 24th warmest winter on record. Quite warm if you think about it. This winter was cooler as last winter. 2011-2012 Winter was the 5th warmest winter on record. A winter without much snowfall, which gave way to drought and warm year in 2012.

If there is a consolation prize for this winter, it was a wetter than normal winter on top of more snow. America had the 22nd wettest winter on record. That is an improvement from last winter, which had the 24th driest winter on record. It is rain that is needed to put a dent on the drought.

Texas
Temperature: 50.07°F
Rainfall: 4.93

1895-2013 Winter Statistics
Winter Temperature Mean: 47.97°F
Standard Deviation: 2.29

Winter Rainfall Mean: 5.10
Standard Deviation: 1.90

Texas had quite a warm winter as it was above the standard deviation. Texas had the 18th warmest winter on record, which puts it in the top 20 warmest winter from 1895 to 2013. The previous winter had the 35th warmest winter on record. 2011-2012 winter was cooler than the winter of 2012-2013.

Texas had the 55th wettest winter on record. Last winter, Texas had the 10th wettest winter on record. Quite a stark contrast if you think about it. A wet winter gives a cooler winter as there are cloud cover and moisture in the air that moderates the temperature. The rainfall amount is within the normal range as it is within standard deviation. Texas could use more rain to put an end to the drought plaguing Texas.

Upper Texas Coast
Temperature: 58.07°F
Rainfall: 11.45

1895-2013 Winter Statistics
Winter Temperature Mean: 55.12°F
Standard Deviation: 2.63

Winter Rainfall Mean: 10.72
Standard Deviation: 3.46

Upper Texas Coast had the 16th warmest winter on record. It was warm even by Southeast Texas standard, even though they have mild winters. Last winter, the Upper Texas Coast had the 18th warmest winter on record. Another warm winter for the record book and back to back, like in 1998-1999 and 1999-2000. The Ghost of Winter Past did not want to leave the Upper Texas Coast.

The Upper Texas Coast had the 42nd wettest winter on record. Last winter, Upper Texas Coast had the 14th wettest winter on record, which occurred in a La Nina winter. Upper Texas Coast is drier than last year. However, in terms of rainfall, Upper Texas Coast had a normal rainfall as it is within the standard deviation. It is still concerning as there has not been a lot of rain lately as Upper Texas Coast is seeing droughts developing.

2012-2013WinterAnalogWeatherOutcome

So, how did my winter forecast hold up? It held up for the most part. East of the Continental Divide had warmer than normal winters, while west of the Continental Divide and Hawaii were cooler. However, Alaska, Western Canada, and Northeastern Canada was warmer than normal. The analog winters of 1951-1952, 1963-1964, and 2001-2002 have Alaska, Western Canada, and Northeastern Canada cooler than normal. In terms of rainfall, it was much wetter in the Midwest, Great Lakes, Southern Alaska, and Western Canada than in the analog winters. It was much drier in the West Coast and Southeast.

2012-2013WinterAnalogOutcome500mbGeopotentialHeight

How was the upper level atmosphere like? For the most part it came close. The North Atlantic Oscillation (NAO) was positive as there is a upper level high pressure over Greenland. There is also upper level ridging over Northwest Africa. On the other hand, there were strong upper level trough over Russia and Central Europe.

I think my winter forecast held up well. I would give myself a A- as there are rooms for improvements. I base analogs on Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and El Nino Southern Oscillation (ENSO). The reason I use PDO and AMO is that they are long term and change about every decade or so. ENSO changes every year, so one year could be La Nina, while the other year is El Nino. El Nino and La Nina have an impact on winter weather.

1951-1952, 1963-1964, and 2001-2002 had cool PDO, warm AMO, and neutral ENSO, which 2013 had. As for spring analogs, I am going to use the same analog winters, which are 1952, 1964, and 2002.

2012-2013 Winter So Far

It is now February and Valentine’s Day is coming. Time to get some chocolate and roses. It is also ever getting closer to spring as days start to get longer and longer each day. How has winter turned out so far? Have my analog forecast come out correct, which I issued back in December? To keep you up to speed, the analog winters I used are 1952, 1964, and 2002. Here is what winter has been like for North America from December 2012 to January 2013.

2012-2013DecJanTemperatureAnomalyNALet’s start with temperature. As you can see in the map, the eastern half of North America has been warmer than normal so far. Greenland is quite warm. The Arctic Oscillation (AO) has been overall negative, while North Atlantic Oscillation (NAO) has been overall positive, which is rather interesting. Normally, if NAO is positive, AO should be positive as well. However, it is not the case. Another piece to the puzzle is the Pacific North America (PNA) and it trends towards positive. A positive PNA means more chance for cold blasts as it creates ridging over Alaska and Northwest region of North America and diverts cold air further south. There were cold blasts this winter, but not anything that is really impressive. The western half of North America has been cooler than normal, with a pocket of warmth in northwestern America and Canada. Northern Canada where it meets Alaska has been very cold this winter, while western Alaska has been warmer than normal.

2012-2013DecJanPrecipitationAnomalyNAPrecipitation rate for most of North America has been within normal. Most areas have seen average snowfall total so far, which is better than last winter. Last winter was dry, which meant less snow on the ground. Southeast Texas, around the Mississippi River basin where Arkansas, Louisiana, and Tennessee meet, and Great Lakes region have been wetter than normal. There was flooding in Louisiana, where some areas saw up to 12 inches of rain. The area around that has below normal precipitation rate is around Vancouver and southeast Georgia. We could use more rain as America is gripped in a severe drought.

2013-2013DecJanWinterAnalogSo, how has my analog forecast hold up? Surprisingly it came close with a few exception. Let’s start with winter temperature. December to January in 1951-1952, 1963-1964, and 2001-2002 were quite warm in the eastern half of North America, while it was cooler in the western half of North America. It is quite cold in Alaska and northern part of Hudson Bay. Strangely, the southern part of Hudson Bay is very warm in those analog years. Greenland is warm in the analog winter years, but not extremely warm.

In terms of precipitation, it has held up to be accurate with the exception of the area around Seattle and Vancouver, which is normally wetter than normal in the analog years. The rainfall has been within average in the southeastern part of Alaska for this winter, which is drier than normal in the analog years. Southeast Texas so far has been wetter than normal, but not by much. In a typical analog year, Southeast Texas gets rainfall within the norms. Not too wet or dry.

2012-2013FebruaryForecastSo, what would February be like? Again, I will be using the analog years, which are 1952, 1964, and 2002. Looking at the February temperature in those analog years, shows cooler than normal February over the Rocky Mountain, Texas, and South. It is warmer than normal over Canada, Midwest, and Northeast. Northern Canada, Alaska, and Hudson Bay are cold in those analog years. In terms of precipitation, it is drier than normal in the West Coast, Midwest, Ohio River Valley, and Northeast. The area which are wetter than normal are Texas, Louisiana, and Mississippi, near the coast. It is also wetter than normal in Northwestern Canada and Southeast Alaska.

What does this mean? I think Texas could see a cooler and wetter than normal February. I do not expect an abnormally cool February like in 2010 or 2011. We are in a pattern of seeing rain up mid February as there will be upper level disturbances and lows traversing across America. I cannot rule out snow in February as in one of the analog winters did have snow on February 21, 1964. Granted, it was only a trace of snow, but snow did actually fall.

2012-2013DecJanTemperatureComparedJust for kicks, here is how December 2012 to January 2013 are compared to past winters since 2009-2010 in terms of temperature and precipitation. It has been a warm winter so far, but not as warm as last winter, which was very warm. You had to wonder what happened to winter in 2011-2012. It felt like Old Man Winter did not want to visit America. There was not much snow cover that winter, which contributed to the drought. Winter snow is inconvenient and annoying to some, but it has a purpose to keep soil moist and have water for farming and drinking. It was cold in 2010-2011 even before February 2011, which brought frigid temperatures throughout America. It was even colder in 2009-2010, which produced one of the coldest winters on record for America, especially in the South, including Texas.

2012-2013DecJanPrecipitationComparedIn terms of precipitation, it is not as dry as most places have seen normal rainfall amount this winter. Last winter was drier, especially in the West Coast and East Coast. The winter of 2010-2011 was drier over a large area due to La Nina. The drought in Texas was under way that winter. The winter 2009-2010 was wetter due to El Nino. It was very snowy winter as many areas saw above average snowfall total. All of America was covered in snow in 2009-2010, the most since 1977-1978, another really cold winter of the late 1970s, which stretched from 1976 to 1980.

Farewell Winter 2011-2012

Winter 2011-2012 has passed into memory lane. Meteorological winter is defined by NOAA as being from December to February. Now, we are heading into spring, which is the start of the severe weather season. It started early with tornado outbreaks that claimed a total of at least 53 lives in the Midwest and South.

Here is the temperature and precipitation outcome. It is based on 1895 to 2012.

Upper Texas Coast 2011-2012 Winter Temperature
2012 Winter = 57.7°F
Mean = 55.1°F
Median = 55.19°F
Standard Deviation = 2.63
Coolest = 48.90°F (1977-1978)
Warmest = 60.93°F (1949-1950)

If you thought this winter was warm, you are right. It has been warm, 19th warmest winter on record. A far cry from last winter and the previous winter. Winter of 2009-2010 is one of the coldest winters on record, while 2010-2011 was cold due to freezes in February. Winter temperature for the Upper Texas Coast in Winter 2012 was warmer than normal.

Upper Texas Coast 2011-2012 Winter Precipitation
2012 Winter = 13.90
Mean = 10.71
Median = 10.19
Standard Deviation = 3.46
Driest = 2.84 (2008-2009)
Wettest = 23.72 (1991-1992)

Winter precipitation for the Upper Texas Coast is above average, but within the norms. Anything above the standard deviation would be abnormal, which would be 14.17 inches or less in Winter. On the flip side, there have been improvements made in ending the drought, but the drought still persists. Also, Winter of 2011-2012 is the 19th wettest winter on record.

Texas 2011-2012 Winter Temperature
2012 Winter = 49.07°F
Mean = 47.96°F
Median = 47.91°F
Standard Deviation = 2.29
Coolest = 42.45°F (1894-1895)
Warmest = 53.13°F (1906-1907)

It was just as warm in the state of Texas, but not abnormally warm. It was the 36th warmest winter on record.

Texas 2011-2012 Winter Precipitation
2012 Winter = 7.39
Mean = 5.10
Median = 4.95
Standard Deviation = 1.91
Driest = 1.56 (2008-2009)
Wettest = 13.23 (1991-1992)

Texas had an abnormally wet winter and that is a good thing for one. Texas is plagued by the severe drought and the winter rains really help. Texas had the 14th wettest winter on record. Not bad despite a La Nina winter and I am very pleased about it.

America 2011-2012 Winter Temperature
2012 Winter = 36.8°F
Mean = 33.00°F
Median = 33.22°F
Standard Deviation = 2.00
Coolest = 27.29°F (1978-1979)
Warmest = 37.17°F (1999-2000)

America too was basking in this warm winter. In fact, winter in America was abnormally warm, that is the 4th warmest winter on record. Only the winter of 1999-2000, 1998-1999, and 1991-1992 were warmer. No wonder why we had little snow this past winter. This is quite a far cry from last and previous winter, which was cold, especially 2009-2010. The warm winter was due largely to a positive Arctic Oscillation and North Atlantic Oscillation. Also, it was La Nina, which means warmer winter.

America 2011-2012 Winter Precipitation
2012 Winter = 5.70
Mean = 6.43
Median = 6.38
Standard Deviation = 0.88
Driest = 4.08 (1976-1977)
Wettest = 8.68 (1997-1998)

The warm winter also means a drier winter. The winter was dry, but not abnormally dry. America had its 21st driest winter on record. The dry winter is concerning for me as the drought is increasing throughout America. An expanding drought in America could lead to higher food prices for everyone. No one wants that for sure. If there is light at the end of the tunnel, La Nina is dying and heading into Neutral and possibly El Nino. If that is the case, we could see rain returning, which would reduce the drought.

Overall, winter of 2011-2012 was warmer than normal. In regards to rain, the further south was wetter, while north and west was drier. The warm winter is likely more conducive for an active severe weather season in spring. The Gulf of Mexico is warmer than normal in winter.

2011-2012 Winter Forecast Part 2

Let’s look at the atmospheric and ocean patterns besides El Nino/La Nina in those analog years. Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) is by season. North Atlantic Oscillation (NAO), Arctic Oscillation (AO), Pacific-North American Teleconnection Pattern (PNA), and Quasi-Biennial Oscillation (QBO) are by month because they can change quickly since they are in the atmosphere, not ocean.

1917-1918
Winter PDO = -8 Weak Cool
Winter AMO = -17.5 Strong Cool
December NAO = -18 Strong Negative
January NAO = -45 Strong Negative
February NAO = +25 Strong Positive
Overall Winter NAO = -12.7 Moderate Negative
December AO = N/A
January AO = N/A
February AO = N/A
Overall Winter AO = N/A
December PNA = N/A
January PNA = N/A
February PNA = N/A
Overall Winter PNA = N/A
December QBO = N/A
January QBO = N/A
February QBO = N/A
Overall Winter QBO = N/A

There is no data for AO, PNA, and QBO, since earliest goes back to the late 1940s or 1950s.

1956-1957
Winter PDO = -12.6 Moderate Cool
Winter AMO = -3.9 Neutral
December NAO = +17 Strong Positive
January NAO = +18 Strong Positive
February NAO = -10 Moderate Negative
Overall Winter NAO = +8.3 Weak Positive
December AO = +0.01 Neutral
January AO = +20.6 Strong Positive
February AO = -15.1 Strong Negative
Overall Winter AO = +1.8 Neutral
December PNA = -3.1 Neutral
January PNA = -11.9 Moderate Negative
February PNA = -11.9 Moderate Negative
Overall Winter PNA = -9.0 Weak Negative
December QBO = -15.02 Easterly
January QBO = -13.05 Easterly
February QBO = -11.89 Easterly
Overall Winter QBO = -13.32 Easterly

2000-2001
Winter PDO = +4.7 Neutral
Winter AMO = -5.5 Weak Cool
December NAO = -22 Strong Negative
January NAO = -1 Neutral
February NAO = -5 Weak Negative
Overall Winter NAO = -9.3 Moderate Negative
December AO = -23.5 Strong Negative
January AO = -9.6 Moderate Negative
February AO = -6.2 Weak Negative
Overall Winter AO = -13.1 Moderate Negative
December PNA = +12.3 Moderate Positive
January PNA = +15.1 Strong Positive
February PNA = -1.6 Neutral
Overall Winter PNA = +8.6 Weak Positive
December QBO = -14.6 Easterly
January QBO = -15.7 Easterly
February QBO = -15.5 Easterly
Overall Winter QBO = Strong Easterly

2008-2009
Winter PDO = -12.7 Moderate Cool
Winter AMO = -2.8 Neutral
December NAO = +3 Neutral
January NAO = +15 Strong Positive
February NAO = -3 Neutral
Overall Winter NAO = +5 Weak Positive
December AO = +6.5 Weak Positive
January AO = +8 Weak Positive
February AO = -6.7 Weak Negative
Overall Winter AO = +2.6 Neutral
December PNA = -14.1 Moderate Negative
January PNA = +6.1 Weak Positive
February PNA = -9.5 Weak Negative
Overall Winter PNA = -5.8 Weak Negative
December QBO = +10.5 Westerly
January QBO = +10.7 Westerly
February QBO = +12.3 Westerly
Overall Winter QBO = +11.2 Westerly

Here is the correlation of ocean and atmospheric patterns on regions in America. They are based on seasonal average anomalies from December to February.


PDO
Of the four analog winters, three were in cool phases. The only winter in a neutral or warm phase was 2000-2001. Pacific can be cooler due to season variables and ENSO . A cooler PDO is more likely to have warmer and drier winters on average. It is opposite when the PDO is a warmer phase. Currently, we are in a cool cycle of PDO. Cool phase of PDO is more likely to see La Nina than El Nino since the water is cooler. The opposite happens when PDO is in a warm phase, when we see more El Nino. PDO impact on temperature and rainfall is similar to El Nino for Texas. Cooler the PDO, the drier and warmer it is. Warmer the PDO, the wetter and cooler it is.


AMO
Two of the four winters were in neutral phase. Two of the winters were in cool phase. Three of the four winters were in the warm phase of Atlantic, which is during the “active” or warm cycle of the Atlantic Hurricane Season. 1956-1957 was during the warm phase from 1926 to 1971, while 2000-2001 and 2008-2009 was during the current warm phase of the Atlantic. The Atlantic can be cooler due to seasonal variation and AO and NAO. 1917-1918 was during the cooler and less active period of the Atlantic, which was from 1900-1925. Currently, we are in the warm cycle of AMO. AMO does not have much of an impact on Texas.


NAO
Two of the four winters had overall negative NAO (1917-1918 and 2000-2001). The winters were quite cold, especially in January of 1918. The Northeast and New England had their coldest winter on record in 1917-1918. The 1917-1918 winter is yet to be beaten even to this very day. December 2000 was cold throughout the nation, especially east of the Rocky Mountains. Houston had its third coolest December on record, only 1983 and 1989 were cooler. A negative NAO leads to cooler winters.

Two of the four winters had positive NAO (1956-1957 and 2008-2009). The winter of 1956-1957 was quite warm, especially in the South and East Coast. 2008-2009 is interesting in that the South was warmer than normal. Up North, it was cooler than normal. A positive NAO leads to warmer winters.


AO
The AO can change quickly within weeks to months. It can go neutral than positive than negative in weeks. The winter of 1956-1957 went from neutral, positive, than negative. The AO stayed largely negative in winter of 2000-2001. AO in 2008-2009 went from positive than negative. A negative AO allows cold air to travel further south than normal leading to freezes, while positive AO generally has a blocking pattern that inhibits cold air to travel southwards. The more negative AO is, the cooler the winters will be, especially east of the Rocky Mountains. A negative AO has been responsible for Arctic blasts in the past.


PNA
There is no PNA data from 1917-1918. Two of the three winters (1956-1957 and 2008-2009) had an overall negative PNA. Only one winter (2000-2001) had a positive PNA. A positive PNA means cooler temperatures and more rain for Texas. A negative PNA likely means cooler temperatures for the Western United States.


QBO
There is no QBO data from 1917-1918. In two of three winters, the QBO was negative or easterly. Only one winter was a positive or westerly QBO (2008-2009). QBO likely has relationship with temperature. On the other hand, there is a relationship with QBO and rain. The more negative or easterly QBO is, the wetter winter is for Texas and the South. A positive or westerly QBO is wetter for the West. Interestingly, for the West, a easterly QBO means cooler, but the correlation is not as strong. It is unclear what impact QBO has on temperature. We do know that QBO happens in the stratosphere and when the stratosphere warms up, it is signs that we may see a freeze, since the energy is being distributed somewhere else.

All the images are from US Climate Division Dataset Seasonal Correlation Page

Conditions for December 2011
ENSO
Moderate La Nina

PDO
Cool Phase

AMO
Cool Phase

NAO
Positive

AO
Positive

PNA
Positive

QBO
Easterly

Data for ENSO is from ENSO Cycle: Recent Evolution, Current Status and Predictions. Data for PDO, NAO, AO, and PNA are from Daily Indices during last 120 days in Ascii format using GDAS. Data for AMO and QBO are from Climate Indices: Monthly Atmospheric and Ocean Time Series

What do I think this upcoming winter will be like? I think we could see multiple cold blasts and winter storms, especially up north. It is going to be dependent on NAO and AO because it can change month to month. If NAO goes negative, we could see more cold blasts in America and Texas. If NAO goes positive, there is likely a period of warmth in the winter. Also, PNA is an important factor as well and changes month to month like NAO and AO. A positive PNA means cooler winter as well. QBO has little impact on temperature, but it could have an impact on rainfall. If the QBO is still  easterly by February, we could see more rain.

La Nina winters are warmer in generally because it is drier. The lack of moisture does not moderate the temperature. This upcoming winter should be a roller coaster ride like last winter. In regards to rainfall, I think we could have periods of rain and than periods of dryness. However, we should prepare if the drought worsens this winter. Let us hope the drought ends in 2012. I think this winter will be average to slightly above average in temperature department. In regards to rainfall, I think the rainfall should be within average or below, which is typical of La Nina.