Feb 15-18, 2013 Storm Summary

February 16, 2013 Snow/Wind

A frontal boundary slowly shifted to the east through the region, producing rain/snow showers with light accumulations inland. This frontal boundary then stalled just off the coast, with a rapidly intensifying coastal storm brushing southern and eastern New England with moderate snow and wind, including Long Island and Connecticut.

 

 

 


February 16, 2013 Storm Archive

February 13 – Snow Tonight, Then Mild Friday
February 14 – Snow Saturday, Then Cold
February 15 – Brief Update
February 16 – Noon Update
February 16 – Evening Update

 


Storm History

As the previous storm on February 13 exited the region, a strong trough began diving into the Midwest, amplifying as it reached the East Coast, while a cold front associated with a weak low pressure in southern Canada slowed down as it reached the region. On Friday night, February 15, the front slowly passed through the NYC area, producing light to moderate rain along I-95 and moderate snow inland.

On Saturday, February 16, the front nearly stalled to the east as a long stationary band of light snow set up from the Carolinas up the coastline into New Jersey, Long Island and southeast New England. A low pressure began developing along the stalled front overnight off the North Carolina coast, beginning to rapidly intensify on Sunday, February 17, as it accelerated and tracked northeast offshore and parallel to the coast; the track was too far east to produce widespread snow across the region, although bands of light to moderate snow, locally heavy, affected eastern New England, with the heavy snow bands staying offshore. The intense low pressure moved onshore over Nova Scotia early on Monday, February 18, at its peak strength with a minimum pressure just under 960 millibars, weakening later on as it continued to track away from the region.

 


Forecasting The Storm

ECMWF run from 2/8 early morning (0z run), showing a strong low pressure just southeast of NYC, a scenario which favors a major snowstorm to the north/west (Image credit: PSU e-Wall).

f240Long Range: As far as least 7-10 days away from the storm, the model guidance indicated the potential for a major storm to affect the region, with both the 0z and 12z ECM runs on 2/8 showing a sub-980 mb low pressure with a major snowstorm. This was followed by the 2/8 18z GFS run and 2/9 0z CMC run, which showed a similar scenario. Occasional storm signals continued with the 2/9 and 2/10 runs as the majority of the operational models, including the ECM ensemble mean, depicted a strong eastern US trough and western US ridge, with either a nor’easter affecting coastal parts of the region or a weaker low pressure staying offshore

GFS run from 2/11 morning (6z run), showing a strong low pressure on top of NYC with widespread heavy snow to the north and west (Image credit: PSU e-Wall).

f150Medium Range: The storm signals peaked with the 2/11 6z run of the GFS, which 144-150 hours out showed an extreme scenario with a 957 mb low pressure tracking over the I-95 corridor, producing a widespread major blizzard across the Northeast region. The 12z run continued to show a major snowstorm but further southeast, off the coast, and weaker, with a minimum pressure of 980 mb, producing 6-12 inches along the I-95 corridor. The majority of the 12z guidance trended in this direction as well, with the 12z UKMET, CMC and NOGAPS showing an intense storm producing widespread significant snowfall as well. The ECMWF, however, differed from the rest of the models and only showed a weak low pressure offshore.

The GFS continued to trend southeast and weaker with the rest of the 2/11 runs, although the 2/12 0z GFS ensemble mean trended towards the previous GFS scenario of a major storm. Throughout the 2/12 day runs, the model guidance gradually backed away from the major storm signal, showing a low pressure offshore that develops too late and too far east to affect the region with more than light snowfall at most. This continued with the 2/13 runs, which showed scattered rain/snow showers across the region with a low pressure developing well offshore.

GFS run from 2/14 morning (6z run), showing an intensifying low pressure east of NYC with light-moderate snow in New England. This run incorrectly developed the 2/15 night rain/snow into the main storm – in reality, the low pressure in this time frame was near North Carolina (Image credit: PSU e-Wall).

f66Short Range: The model guidance gradually trended towards some more impact in the region, showing a weak wave of low pressure producing light rain/snow along and west of I-95 on Friday night, 2/15, followed by a coastal low brushing New England with light-moderate snow. The 2/14 12z GFS and CMC runs ended up west of the previous runs, with a more significant low pressure producing 4-8 inches of snow in the area and 6-12″ with near blizzard conditions in New England. Compared with the actual result, the 2/14 12z runs were not far off with depicting minor accumulations along and west of I-95 on Friday night, but then developed the coastal low too close to the coast. The ECM, however, remained further east, showing an insignificant event.

The GFS and CMC runs on 2/14 and 2/15 continued to occasionally show heavy snow in New England; the GFS runs on 2/15 12z and 2/16 12z showed over 12 inches in Rhode Island and eastern MA, while the 2/15 18z run kept the heavy snow offshore. The ECM, meanwhile, slowly edged further west, with the 2/15 12z run showing at least 1″ of snow in the NYC area and a swath of 3-6+ inches of snow in eastern New England. The GFS slightly corrected to the east late on 2/16 and on 2/17, with a model agreement emerging regarding light-moderate snow in eastern New England.

 


Storm Impact in the Northeast

Regional radar image from 1:58 AM 2/17,  from the National Weather Service. Light to moderate snow can be seen over central-eastern Long Island and southeastern New England.

Precipitation first affected the region on Friday night into Saturday morning, February 15-16, as the cold front slowly made its way through the NYC area. Although temperatures aloft were below freezing, surface temperatures were in the upper 30s and 40s, resulting in rain for most of the NYC area, although interior north/west locations such as NW NJ and SE NY recorded light to moderate snow, locally heavy at times. Regionwide, a band of moderate snow set up over western Maryland into SE PA, NW NJ and eastern NY, where light accumulations were observed. (1-3 inches).

By Saturday morning, February 16, a narrow yet long band of light precipitation spread from the Carolinas up the coast into New Jersey, Long Island and south/east New England. Scattered rain/snow showers affected the NYC area throughout the day with little to no accumulations. As the low pressure began to organize off the North Carolina coast in the evening, a band of heavy snow developed and stalled barely a few miles off the coast, extending from southern Delaware to New Jersey, while light to moderate snow showers affected the coastal regions.

Later overnight into Sunday morning, February 17, the heavy snow bands stayed primarily offshore while lighter snow bands extended north into the eastern half of Long Island and southeastern New England. A wind driven moderate snow affected these regions while gradually extending north into Maine, where near blizzard conditions were observed with heavy snow and strong winds creating low visibility. Snow gradually ended from south to north on Sunday as the storm continued to rapidly intensify and approach Nova Scotia.

 


Storm Snow Totals

The map below shows estimated snow totals from the storm across the region, excluding lake effect snow, based on NWS storm reports. Actual totals may be locally higher/lower than shown below.

feb1618snow - Copy (2)The first part of the storm affected the region on Friday night-early Saturday, February 15-16, producing rain and snow; a narrow band of 1-3 inches of snow set up over western Maryland into southeast Pennsylvania, NW NJ and eastern NY state, with up to 2 inches recorded in Sussex county in NW NJ and Orange County in SE NY. With the second round on Saturday night-Sunday, February 16-17, light accumulations under 1-2 inches spread from southeast Virginia up the eastern NJ coast. At least 1 to 4 inches of snow were observed in Long Island and the eastern half of Connecticut, with higher accumulations towards Rhode Island and southeast Massachusetts, where at least 3 to 7 inches of snow fell. The highest accumulations fell in eastern Maine, where snow amounts were locally as high as 10-12 inches.

Below is a list of selected snow reports across the area from the National Weather Service, listed by highest total from each county:

Southern CT:
3.3″ – Stonington, CT (New London)
1.0″ – Milford, CT (New Haven)

Long Island:
3.0″ – Southampton, NY (Nassau)

 

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