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.
Let’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.
Precipitation 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.
So, 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.
So, 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.
Just 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.
In 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.