El Nino Or La Nina this Year?
In my little sneak peak to everyone on the homepage of the website, I displayed an article on what this years El Nino or La Nina question, would have the most logical answer and actually have a greater chance of happening. (Click Here to see article) but as of right now I am thinking this year will be a weak la nina, which is right in line with the national weather service.
Winter of 2009-2010- Moderate El Nino
Winter of 2010-2011-Strong La Nina
Winter of 2011-2012- ? (weak la nina) 65% confident
NAO, AO, PNA. How Will They Act?
This is a particularly hard question to answer. On the previous forecast I posted that I like to follow the trend/pattern in order to see if there is any consistency and then make a prediction on it. On my last winter outlook video I posted that I thought we would be more on the positive side for the NAO and AO, But over the past few months, really starting after I said that it seems, that the NAO and AO have been consistently Negative the NAO more than the AO. The PNA has remained either neutral or positive for several months. This happened most of last summer by comparison. So I now think will will remain in the pattern for a while of a negative NAO and AO and a neutral to positive PNA. for this upcoming winter. This is subject to change, because if there is one thing I definitely know about the weather, it is that nothing in it ussually stays the same. But we will see what happens as we head into September when my 3rd update will be released!
NAO Prediction- Negative most of the time
PNA Prediction- Positive most of the time
AO Prediction- Negative to neutral most of the time.
What Is the NAO, AO, & PNA?
The North Atlantic oscillation (NAO) is a climatic phenomenon in the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level between the Icelandic low and the Azores high. Through east-west oscillation motions of the Icelandic low and the Azores high, it controls the strength and direction of westerly winds and storm tracks across the North Atlantic. It is part of the Arctic oscillation, and varies over time with no particular periodicity.
The Arctic oscillation (AO) is an index (which varies over time with no particular periodicity) of the dominant pattern of non-seasonal sea-level pressure variations north of 20N latitude,
The Pacific-North American teleconnection pattern is a climatological term for a large-scale weather pattern with two modes, denoted positive and negative, and which relates the atmospheric circulation pattern over the North Pacific Ocean with the one over the North American continent.
Definitions from wikipedia.org
Reflection of the 2000-2011 Winters: The Effect of the AO, NAO & PNA
Now for those that think that just because you have a certain type of condition in the pacific means that you are going to toast or freeze in certain areas of the US. Well you would be partially right. But when you look at the 11 year history of winters you will see that the winter has a little more influence than a La Nina or El Nino or La Nada (Neutral).
When you look at the history there were 5 la nina winters, 4 el ninos and 2 Neutral. ( please note that 2010 & 2011 are not included in the picture). Anyway 2 out of 4 of those El Nino’s (The most recent being 2009-2010) winter’s were cold and snowy in the Easter half of the Nation while the Western half stayed warm. However an el nino based off of the history over the past decade does not always mean cold & Snowy in the east. 1/4 of the el ninos was warm in the east and relatively cool in the West, and 1/4 was warm pretty much nationwide. What was the difference most likely the state of the NAO, AO and PNA. Looking at the la nina winters that also does not guarantee a great winter for the west. But if conditions are favorable, like with a negative PNA, positive NAO & AO they would be very cold and snowy most likely.
Rembemer last year, a lot of people thoughgt that just because it was a la nina winter, and a moderate to strong one at that, people thought that it was going to be milder than average in the southeast & Mid-Atlantic with most of the Snow in the interior. And then a January thaw. It was actually fairly cold and snowy along and in the Southeast & Mid-Atlantic. (Besides Central Virginia, Washington D.C & Central Maryland, We were in the snow hole last year, I do not expect a repeat of the snow hole in the same area but someone will expirence it.) Why because the NAO, AO and PNA were all rocking and bocking in a favorable patter for the Eastern half of the nation.
So yes an el nino or la nina situation is important but it has to have ther right variables (NAO, AO, and PNA) working along with it. Just like any pattern. The type and strength of a la nina, and el nino’s are also important as well.
So here we go, I am going to break down the winter forecast for each region and at the end show you my nationwide outlook. Remember in a La Nina winter, everything is really dependant on the condition of the NAO, AO, and PNA. Also since it will most likely be a weak La Nina we will factor that in a well.
As For the Mid-Atlantic, it looks like it will be another colder than average winter for you. The snow hole that was over the Southern Mid-Atlantic last year, D.C, Maryland and Virginia I do not expect to be here again. I expect slightly bellow average temperatures for I-95 and points east, which include the major cities of Philadelphia, Baltimore, Washington D.C. and Richmond. This may actually be a good thing that we are not in the depth of the cold or else it may push storms farther off the coast. I also expect it to be wetter than average. So Cold & Moisture usually equals snow/Ice so expect a repeat of last year for most areas in the mid-Atlantic. That is how it looks now. Things may change!
Last years winter in the Northeast was nothing short of amazing. You guys had snowstorm after snowstorm after snowstorm. Several areas individualy broke snowfall records for the season. I do not expect a repeat performace like that, but another cold and snowy winter could be on the way for areas in the Northeast, As I expect once again areas Just east of the I-95 corrideor to be slightly colder than average, and areas west of I-95 to be much bellow average in temperatures, and above average precipitation.
Perhaps some of you in the Midwest who like snow fondly remember the massive snowstorm in Chicago that brought out the most amazing forecasting I have seen from him in a while. The Midwest received several snow and Ice systems that plowed through there. Usually they were clipper systems that brought a good swath of 3-5″ of snow with Isolated 8″ events. But for the most part that large Blizzard that shook Chicago may be a sign of things to come this winter. If you are in the upper Midwest like, Wisconsin or Minnesota I expect near average Precip with colder than average temperatures. Areas Like Chicago and Ohio may be in for a snowy than average winter and a colder than average one.
Chicago Forecast- Cold and Snowy, perhaps ”A” brief mild spell.
As For The Pacific Northwest I expect a Cold and Wet winter for you guys. I do not expect as much of the moisture you will get to be transitioned over to snow, like it will be in the East, Due to you guys always having an onshore flow keeping temps in the upper 30′s and low 40′s. But I do expect you to still be slightly above average in snowfall.
Seattle Forecast- Cold & Wet, slightly above average snowfall
Last But Not Least The Southeast I Expect in general for most of the southeast except for the gulf coast to be colder than average. Well let me just put it this way, conditions should be similar to the last couple of winters. If you live in Western or Southern Texas and Western Oklahoma, slightly milder than average conditions with average precip should prevail and along the gulf coast should also be slightly above average when it come to temperatures.