Rockville Centre, NY blanketed with several inches of snow on Friday, March 20. (Doug Simonian)

First week of Spring looks to only be a technicality

Happy Spring, everyone! Well, sort of. Most of the area was blanketed with between 4 and 7 inches of snow on Friday, which was the first day of Spring. This has helped to bring many official weather stations in our area to over double their average snowfall.

Central Park: 4.7″ on March 20-21, 18.6″ of snow in March, 50.3″ seasonal total.

LaGuardia: 4.6″ on March 20-21, 17.2″ of snow in March, 53.8″ seasonal total.

Islip: 5.5″ on March 20-21, 17.9″ of snow in March, 62.2″ seasonal total.

The snowiest March on record was a whopping 30.5″ in 1896, which is unlikely to be broken this year. But snowfall nearing 20″ this month, combined with temperatures averaging between 3 and 4 degrees below average so far has certainly helped to contradict the fact that March is “Meteorological Spring”.

Unfortunately, the cold pattern looks to be continuing, with perhaps even another chance or two of snow over the next ten days.

Today has obviously been a well below average day, as high temperatures have struggled to reach 40 degrees, compared to an average of 51 degrees. Temperatures tonight will fall below freezing, and temperatures tomorrow should hold in the upper 30s. Fortunately, the sun angle this time of year is high, so the snow will continue to melt.

Today's NAM Model valid for tomorrow afternoon shows plenty of cold air filtering into the region.

Today’s NAM Model valid for tomorrow afternoon shows plenty of cold air filtering into the region.

The culprit of this is more ridging in the higher latitudes, which has helped to displace a piece of the Polar Vortex into SE Canada, which provides the area with plenty of cold air. Tomorrow, the piece of the Polar Vortex will make its closest approach, leading to strong NW winds, temperatures only holding in the upper 30s during the day, and crashing into the upper teens to low 20s tomorrow night! The strong winds and cold temperatures will allow Wind Chills to fall to the upper single digits to low teens tomorrow night. For perspective, the average low this time of year in NYC is 36 degrees.

The cold will continue to hold its ground on Monday, before a slow moderation trend occurs ahead of a cold front. Upper 30s on Monday, low to mid 40s on Tuesday, and then Wednesday looks to be the winner of the week with temperatures rising into the low 50s with sunshine.

Wednesday night and Thursday is when the cold front will take its closest approach. This will lead to periods of rain, but with still initially mild temperatures. However, on Thursday night, the cold front will cross the region but be slow to depart, and when this is combined with yet another developing ridge in the west, troughs and waves of energy could result for Friday and next weekend.

Today’s Canadian Model valid for Friday shows a large ridge developing in the West and a downstream sharp trough in the East. Strong waves of energy ridge along the departed cold front, leading to a snowstorm (PSU-Ewall).

With the March 5 snow event, waves of energy rode along a departed cold front and gave the area 6-8″ of snow, so we have seen these setups before. Given the strength of the ridging out West, another good shot of cold air should be dislodged into the region on Friday and onward. The Canadian Model shows the extreme scenario of lagging very strong energy immediately behind the front and turning it into a snowstorm. Most other guidance, however, shows the ridge out west quickly rolling eastward, as energy crashes into the Pacific. This in turn would deamplify the pattern and force any storm system to develop well to the east of our area. Although we are leaning towards the latter (out to sea) scenario at this time, we will still have to monitor the data this week. As long as persistent ridging redevelops in the West, high latitudes, or both, it remains possible that a wave of energy could amplify into the cold air and produce snow — if not next weekend, then perhaps a few days after.

And even if it doesn’t, the cold, for the most part, looks to be holding on. But hey, it’s only 91 days until Summer.