Thursday, September 3, 2015

Winter 2015 2016 preliminary outlook

Here is a look at my preliminary winter 2015-2016 outlook, My final outlook will be posted in 4 to 6 weeks.

This will be based on Sea Surface Temperatures (SST). The final one will include SST but it will have other factors involved as well.

The last few years I've released my preliminary thoughts for the upcoming winter around this time.  But this year, I've tried something new; I also posted how things looked to be shaping up over the Summer and how those would impact the coming winter.

Before I start talking about the winter...I want to look at how the summer turned out.
Temperature wise the northeast saw a slightly below average to average Summer.  The precipitation pattern has been active, but still ended up being below average.

Here are a few charts I made up to show how the current setup matches what we've seen this summer. 
Above is taking the analog years and put them into a chart. The chart shows the average temperature pattern we should have see this summer.


Above is shows how the last 90 days shaped up in the temperature department. You can see that it matches up well to what the analog years said should happen.

If you've followed my Facebook weather know I've been saying for about two months, that September would start out warm, then cool off around mid month, then heat back up for the end of September into the first part of October. Here are a few charts that show the models agreeing with my thoughts. 

 Above shows the cool down for mid month..


Above is showing how we warm up to above average temperatures for the last half of September into the first part of October.... After that I do think we will see things cool off a bit for the rest of October into November....before we warm up again for December.

The above images show how the precipitation has shaped up so far this Summer.

The reason I've showed the last 90 days, is to give you confidence that this analog approach to doing long range forecasting is a very good tool.

Ok what about the upcoming winter?:

My Analog years:

1919-1920, 1957-1958, 1972-1973, 1982-1983, 1991-1992, 2009-2010, and last winter 2014-2015.

ENSO El Nino:

As most of you know, we have a strong El Nino right now.

An El Nino winter tends to be milder, than a weak El Nino or a La Nina. But Like I've posted before, the PDO, AMO, AO, and the NAO also have a lot of influence on our climate up here in the Northeast. Below I will post images of our current El Nino and how our current pattern compares to winter 2014 - 2015.

But first, I've been saying for the entire summer, that the current El Nino was going to shift west later this fall into the winter. This is now starting to happen. Here is the Current El Nino, I've also place a chart showing the El Nino regions.

Here is what the El Nino looked like last month.

And here is July

You can see the SST off the West Coast of South America are cooler than they were a month ago. The warmer water is a little farther west.

Here is last years SST setup.

I've marked five areas that have a major influence on our temperature patterns.  The sea temperatures in these areas are the reason last winter was so cold.

1) Warm SST in the Gulf of Alaska. This correlates to a ridge out west and a trough over the East.  

2) Warm SST off the West Coast and the Baja. This also correlates to cold in the Northeast.

3) When we see cooler SST's northwest of Hawaii, we often have colder air in the Northeast and Mid Atlantic.

4)  A weak El Nino Modoki also means it's typically cold on the East Coast.

5) Cold SST's in the North Atlantic around Greenland, is a good sign for cold in Eastern Canada and the Eastern U.S.

Here is the current setup.  I've marked the same five areas.

You can see area 1 has extended farther west.

Area 2 is much warmer and also has extended west.

Area 3 is still cold but the warmth to the east has eroded it's over all size a little.

Area 5 is still cold.

The biggest change is area 4.

The warm El Nino will have an impact on our winter of 2015-2016.

A cool La Nina or a weak central based Modoki is typically a cool sign in the Northeast. Last winter we had a neutral ENSO or a weak Modoki El Nino. This effected the Jet Stream. it helped setup the ridge out west and the persistent trough over the East. It also allowed the southern sub tropical jet to move further north....which helped the northern and southern jets to phase.  This is why New England saw all the snow.

The warm El Nino is going to effect our fall into winter. As I said the current El Nino is starting to shift west. I do expect this to continue into the first part of winter, I also expect the El Nino to be weakening late fall into winter. . The question is how far west and will the El Nino weaken?

Pacific Decadal Oscillation (PDO):

The PDO involves the warm SST in the Gulf of Alaska and Pacific Northwest.  Here is a chart that shows the typical impact of the PDO warm and cool phases. 

Here is how the years with a strong El Nino, stacked up to the years that had a weak El Nino.


1997-1998 was a super El Nino.  The winter of 1997 - 1998 was extremely warm in the Northeast. But 2015 -2016 has a different set up.....

The big differences are the warm waters around Greenland, the warm waters northwest of Hawaii. and the PDO had a much weaker warm phase.

So while the strong El Nino is hinting at a warm winter, the PDO is saying the exact opposite.  The El Nino will have a big impact, but of the two, the PDO will have a bigger impact.

 As we head into fall.  I've already shown how September looks to be warm.  I think we will see things cool off a little for October and November. But we will warm back up for December.

Using the current factors here is how December looks to be

When I factored in the Analog is how things look to unfold this winter January into March.....

February is looking to be very cold.

Here is how the precipitation outlook looks to unfold....if things trend the way I think they well.

So right now this is how it looks to be this winter.

Heading into winter October and November will seasonally cool. Then we will see a big warm up for December.

Winter will start out mild. But then things look to get cold for January, February, and the first part of March.

Temperatures look to be below average for the southern tier of New York State (south of the Mohawk Valley), Southern New England, Pennsylvania, and the Mid Atlantic. With Northern New York and the Rest of New England seeing average to slightly below average temperatures. 

The indications are that around the Great Lakes through Southern Pennsylvania and into the Mid Atlantic would see lots of snow.... amounts of  40% to 50% above average are looking possible. Northern Pennsylvania and New York State south of the Adirondacks would see average to 25% above average....Northern New York and northern New England look to be around average........

Here are some rough maps showing what I've just said.

Snowfall outlook

Precipitation outlook

Well that's about it.  What I've shown here is now things look at this time... I will modify all of this when I issue my final outlook sometime in October. 


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