A look back at winter 2017-2018

This will discuss the major driving factors that made winter 2017-2018 what it was. It will also show the major events for each month.

A look back:

2017 was a warm year.  East of the Rockies saw heat records broken for March through October.  Here in the Northeast  October was  overall the warmest on Record.  November the pattern went back and forth between mild to cool. There was an arctic outbreak that started in the Midwest on November 9th. The air mass moved east over the Great Lakes and into the East Coast. Those downwind of Lake Ontario and Lake Erie saw a significant lake effect event. The area of low pressure brought a foot of snow southeast of Lake Erie. Downwind of Lake Ontario, parts of the Tug Hill saw upwards of two feet of snow. But overall November ended up being doggedly mild. Here are the top 10 years for warmest Autumn in the Northeast.......  1931, 1947, 1953, 1961, 1999, 2001, 2007, 2011, 2016, 2017.

Winter 2016-2017 saw two meter temperatures well above normal from November through February. There were a few very limited cold spells.  Because of the warmth snowfall was severely below average. It wasn't until March that winter like temperatures showed up.

Looking back at those warm Autumns most of the following winters ended up being lackluster with above average warmth and below average snowfall.  One of those winters was 2011-2012 one that many have dubbed "the year without a winter" The only winter that bucked the trend of mild winters was 2007-2008.  2017 was so warm it's no wonder that many winter outlets and Meteorologist were calling for a warm winter with below average snowfall. I wasn't one of them, nor were members of my weather team. Jamie Mahoney, Robbie Venditti, and Joe Karnik. We were calling for almost the exact opposite of most weather outlets.

Here is a link to my 2017-2018 winter outlook.     

 

Here is a look back at winter 2017-2018:

Teleconnections:

The El Nino-Southern Oscillation (ENSO) over the winter featured a east based weak to moderate La Nina. The  Quasi-Biennial Oscillation (QBO) was also east based. The QBO has a big influence on temperatures in North America. When the QBO is east based, the Northeast and Mid Atlantic is more prone to see high latitude blocking and ridging in the west. The East Pacific Oscillation (EPO)was predominately negative.  Winters with a negative EPO tend to be colder than average.   Over the winter we also had very low solar activity. Winters with low solar activity tend to end up colder on average.

December:

After a very warm Fall December started out mild. But by mid month arctic air plunged into the Northeast. By Christmas the Northeast was locked in a block of ice. Most locations saw record lows from Christmas to the end of the month.

January:

The record cold from December greeted those celebrating New Years Eve. Those who braved the cold in Times Square saw the coldest New Years ball drop in several decades. In fact it was so cold that many places canceled New Years Eve celebrations altogether.  On the 3rd -5th a Nor'easter brought heavy snow. Winter storm warnings stretched from Florida into New England.  New Jersey to Northern New England saw several inches of snow. By the 8th temperatures rose to well above average levels.  Over just a 4 days, the warm temperatures melted most of the snowpack in the Northeast. The entire Northeast saw huge ice jams that lead to significant flooding.  The warm up didn't last long and by the evening of the 12th arctic air once again had many of us in its grip. Most places in the Northeast saw a 45 to 60 degree drop in temperatures in only a few hours.   The arctic cold once again retreated north around the 17th. This 2nd thaw lasted to the last of January. The 2nd thaw didn't get anywhere near as warm as the 1st thaw. But lasting nearly two weeks it still melted a lot of snow and ice even on the Great Lakes.  Downwind of the Great Lakes, saw copiousness amounts of Lake Effect snow.

 

 

 

February:

La Nina's are often erratic.  During an La Nina, the Madden-Julian Oscillation (MJO) can be a big factor in influencing the pattern. We saw this happen in February. The record breaking warm temperatures cooled by February.  The first week of February it was cold enough for snow across northern New York State and northern New England.  The cooler and snowy start to February ended as we approached mid month. The pattern flipped back to above average warmth, allowing February to end as one of the warmest overall on record. The flip back to warm was a result of the MJO stalling in phase 7 for 21 days. During February phase 7 is a warm signal.  We had a historically strong area of high pressure off the Southeast Coast. This caused a heat dome over the East Coast. The Jet Stream was very wavy. The eastern ridge was well north into northern Canada, with a deep trough out west. The jet stream orientation allowed the clockwise motion of the air flow around the high pressure to drive record breaking warmth into the Mid Atlantic and Northeast. While the trough out west brought cold arctic air into the west and Rockies.   By the 28th of February all the cities in the Northeast were in the 80's.   The lake snow belts saw an abundance of lake snows for February as well.  

 

 

The 2nd half of February is when my winter outlook deviated from the actual pattern. I had not counted on the MJO stalling for a record 21 days.

 

March:

March came in as a lion. The pattern returning to below average cold and snowstorms brought my winter outlook back into focus. The warmth during the last half of February became history when the pattern changed back. The MJO finely went into the cold phases. The shift to the cold phases 8-2 allowed blocking to develop near Greenland.  We saw the ridge develop out west and the trough to develop over the East Coast.  The southern branch of the jet stayed active, which allowed the southeast ridge to interact with the northern jet stream. This was the perfect environment for Northeast snowstorms. March brought 4 nor'easters to the Mid Atlantic and Northeast. The 1st was March 1-3, 2018. The 2nd was March 6-8, 2018. the 3rd was March 12-14. and the 4th was March 20-22, 2018. The nor'easters brought feet of heavy wet snow to the Mid Atlantic and Northeast. The high winds and heavy snow led to hundreds of thousands of power outages due to downed trees and power lines. Coastal flooding was also a huge problem.

 

In retrospect:

When I issued my 2017-2018 winter outlook I Stated that Northern Pennsylvania New York State and New England  would see below average to well below average temperatures, with above average snowfall. I showed how the snow belts would end up with well above average snowfall. I outlined how Southern (especially southeast) Pennsylvania and the Mid Atlantic would see more in the way of seasonal to slightly above average snowfall and temperatures. Even with the warm spells we had, winter 2017-2018 saw overall below average temperatures. The major cities saw above average snowfall, with Northern New York and New England ending up with very ample snowfall.  There is time to even add to seasonal snowfall totals, as I always say from first flake to last flake.  April is going to be an overall colder than average month. The first half of April does have the chance to see more snow. The pattern does support the idea of the possibility of another coastal type storm during the first 10 days of April.

 

Here are some seasonal snowfall amounts for the winter so far.  They are a testament to the fact that winter 2017-2018 was stormy and not the lack luster winter many think it was.

 

 

All in all my winter outlook ended up being very close to what ended up happening.