We’ve all heard it before: “There will never be another storm like the Blizzard of ’96”.
And then there was.
This past weekends blizzard will be remembered for many things. 30 inches of snow at Kennedy Airport, drifts above windows and along sides of homes, strong wind gusts and damaging coastal flooding (yes, Gov. Christie). Meteorologically, however, it will stand as a testament to the fact that analogs, no matter how wild they may seem, can be a tremendously useful tool in forecasting.
During the medium range period on forecast models, specifically between days 3 and 5, analog tools and algorithms were continuously signaling the Blizzard of 1996 (January 6-8, 1996) as a tremendously high percentage analog. The evolution of the storm system at multiple levels of the atmosphere was comparable to what forecast models were indicating. And as it turned out, the Blizzard of 2016 would have a very similar evolution and outcome to the famed ’96 Blizzard.
The Pattern Evolution
Earlier this January, a large ridge of high pressure developed over the Kara Sea. This is what is known as a major tropospheric disruption to the global weather pattern. Essentially, the lower atmosphere featured such an anomalous ridge, that it altered the circulations around the globe. In fact, the ridge this year in the Kara Sea was so strong and anomalous, that it broke the height record at 500mb (the middle of the atmosphere) in that region for the months of December, January, and February. The development of this ridge caused a tropospheric pattern change that eventually aided in the development of high latitude blocking, colder air, and chances for snow in our part of the world.
The MJO, which was progressing through Phases 7 and 8 during the same time, also enhanced a large ridge from the West Coast of the United States into Western Canada. This initiated a pattern change with a crashing Arctic Oscillation and a negative NAO over Greenland by mid January.
The pattern prior to the Blizzard of ’96 was, in actuality, not all that similar to the Blizzard of 2016. A different ENSO state (Weak La Nina), and a strong -NAO were in place prior to the storm. Interestingly enough, there was an anomalous and strong ridge near the Kara Sea that January of 1996 — but it was not responsible for the blizzard or a pattern change prior to it, as it actually developed after the Blizzard.
Atmospheric progression similarities
The similarities between 2016 and 1996 became much more apparent as the storm grew closer, in the medium range. A large trough in the Gulf of Alaska was present for both storms, allowing a ridge to amplify on the West Coast of the United States about 3 days prior to both storms. This ridge aided in the northern and southern stream disturbances phasing over the Central Plains States.
Both storms also occurred within a transitional period of the AO and NAO regions. This allowed the amplifying shortwave more space to move northward up the East Coast of the United States. Pieces of the Polar Vortex remained over Eastern Canada during both systems, as well, helping to keep cold air in place.
Interestingly enough, analysis of the mid level pattern shows that in 2016, a shortwave rotating around a piece of the Polar Vortex moved through New England just one day prior to the storm. This helped enhance a confluent flow over the Northeast US as the storm came up the coast, keeping the heavier snow bands near our area and inhibiting their movement northward.
Both the Blizzard of 96 and the Blizzard of 16 featured very similar surface level progressions. A low pressure center moved into the Tennessee Valley before transferring to a surface low off the Southeast US Coast. The eventual track of the surface low pressure up the Eastern Seaboard was also quite similar, with the main difference being that the Blizzard of 2016 did not progress as far northward as the Blizzard of 96 — again, attributed to enhanced confluence to the north.
Stronger subsidence and a farther south surface low track resulted in lower totals to our north over New England. But that subsidence also enhanced the bands of heavy snow in our area. With sinking air enhanced to our north, and moisture and lift surging into our area from the south, bands of heavy snow were locked in over the area for 12 or more hours. This led to prolific snowfall totals and record breaking snow accumulations.
Cold Airmass and Storm Dynamics
A 1042mb artic high to the north supplied a very deep artic antecedent airmass over Northeast US during the Blizzard of 1996. Surface temperatures were locked in the teens for most of the event in the New York City metro area. Snowfall ratios throughout storm where running 20 to 1 or higher, making the snow very light.
This deep artic airmass coincided with a modest 30kt southeasterly 700mb jet, ahead of the storm. This lead to more overrunning bands of snow with snowfall rates frequently between 1″-2″ over the Northern Mid-Atlantic on January 7th, 1996. With confluence weaker, more frontogenesis was able to push further north into Hudson Valley and New England.
The antecedent airmass was not as deeply cold for the Blizzard of 2016. The high to north was around 1032mb. Warmer, drier air in the mid-levels caused what we called in-office “poor snow growth slot” early Saturday morning. However, once the storm began to deepen and consolidate more off the Delmarva coast, this slot began to fill with more snow growth and ratios rose to about 12 to 1 on average.
Heavier bands with snowfall rates between 2″-3″ developed over Eastern PA, Northern NJ, New York City, and Long Island during the late morning and afternoon hours on January 23, 2016. A 65kt southeasterly 700mb jet up against stronger confluence to the north enhanced very strong frontogenesis over these regions. Stronger lifting here, to lead to more subsidence over the Hudson Valley and New England during the day.
These two storms were remarkably similar. Throughout the evolution of the system in the medium range, Jan 6-8, 1996 was flagged as the #1 mid and upper level atmospheric analog on multiple sources of information. This, obviously, is no surprised when we take a look at how each storm evolved.
Despite the similarities, the differences are also striking, and a testament to the fact that no two weather patterns..no matter how similar they may seem..will behave the same.
This post was written and compiled by John Homenuk, Doug Simonian, and Miguel Pierre.