Thursday, October 22, 2009

Winter 09-10 Forecast

After hours upon hours of going over the climatology records, looking at past years, investigating current trends in the atmosphere and oceans, even some math (which Im not good at), and using some personal knowledge I think I have somewhat of a good idea what is in store for this winter season. You may want to go get some hot coco and a pastry before you start to read this, because it is kind of long.

Let's first take a look at what I believe to be one of, if not the greatest influence on our winter patterns, the ENSO, or as most know it the "El Nino Southern Oscillation". This image actually updates on its own so you can always come back and check it to see what is going on. As of right now (Early October) we have a weak El Nino which is becoming even weaker, more toward a "neutral" phase. Take a look for yourself:

In the past years we have been in a positive phase of the ENSO know better as "La Nina", but that has finally ended. In those years we have a lot of freezing rain and sleet, and that was a direct cause of the La Nina because it pumped up a lot of upper level warm air which melted the snow in the upper atmosphere and refroze either at the surface or just before. Last year northwest Jersey picked up 45"-65" inches of snow (elevation depending) with a weak La Nina and our snows where still affected by a decent amount of ice. And the year before that with a much stronger La Nina brought 25"-35" inches, and A LOT of ice. I actually remember somestorms dumped 6 inches of pure sleet! Several times! And that really lowered snow totals, this year, it's not going to be an issue :)

What about this years ENSO phase?
"El NiƱo is expected to strengthen and last through the Northern Hemisphere winter 2009-2010." (From the climate prediction center)

Now I realize that I am not a climatologist, but I strongly disagree with the CPC on this, and I have good reason. For one they are forecasting a somewhat strong El Nino to form throughout the season but in the past month has totally reversed from what they were forecasting. Take a look below, does it look like it makes any sense? It doesn't... This is why I'm forecasting a neutral phase in the ENSO if not slightly positive.
This is what they were forecasting: (Sorry for the poor quality. If you see where it first starts to rise thats where the rise was in the image above. That strong el nino forecast had it very strong for mid October, but look above. It went down.)

The Pacific Decadal Oscillation?

The PDO is cycle that goes on in the northwest Pacific Ocean, along the Alaskan and Canadian coasts. There is a positive cycle and then a negative cycle. See below:

Unfortunately I am not as familiar with the PDO as I should be so here is quote from Accuweather's Joe Bastardi:

"My latest evaluation of the state of the Nino finds the only negative value is the global atmospheric angular momentum, which is the great regulator of the pattern. Its negative value acts as a cap on how strong this can get, which is borderline moderate for the start of winter.

The recent crash of the SOI means this will intensify. This is a crucial aspect of my winter forecast as the warming of the ONI areas means the PDO will warm, and a warming PDO in the heart of the cold overall PDO (multi year, multi decades) has led to some interesting winter implications. As important, it means the Mei analog to 1951-1952 will fall by the wayside"

The North Atlantic Oscillation?

The North Atlantic Oscillation or NAO is the most important pattern you can look for when forecasting weather events in the Northeast United States all the way to Europe. Typically the weather in the northeast seems to be a carbon copy of what's going on in across the north atlantic in Europe. Now I would get into detail but I need to shorten the blog so if you are not educated in the NAO check the link:

When looking at the NAO a negative phase means cold and snowy conditions while a positive is the opposite. This is a live image so you can always come back to this blog and check on its progress, or check out the same links on the right hand side of this page.

How much snow?

This is my general idea of this years snowfall totals. Just please note that not all colors are in intervals of 5 inches, several are a span of 10 inches. This is based on a 150% above normal snowfall. NYC will finally get above 40 inches and the ski areas of Sussex County like Mountain Creek, Hidden Valley, and High Point XC should get upwards of 80 inches + at the summit. It's going to be a great year!

  • Neutral Phase to slightly + ENSO
  • PDO will turn warm mid winter
  • Look for negative NAO values
  • Means colder and snowy conditions
  • Snowfall 150%+ of normal
Now I'm not going to try and forecast month to month, but at the beginning of each month I can attempt an "overview" of what is to come. This winter will be noticeable different than the previous ones in past years, this time expect mostly snow events and ice may be a thing of past until La Nina develops again. Wax your boards and take the ski's out of the basement, it's going to be an amazing season. That is if you like powder anyway...

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