Posts

Cold air filters in, light snow likely this week

Temperatures fell back towards normal on Monday (it wasn’t hard to notice the lack of warmth and return of colder wind), with highs generally only reaching the mid to upper 30’s throughout the area. While this certainly felt more chilly than what we experienced this weekend, the real chill is still on the way this coming Tuesday and is expected to continue through the week. More interestingly, a parade of disturbances is likely to traverse the country from the Pacific northwest towards the East Coast, providing multiple opportunities for wintry precipitation in the area.

The main difficulty in the forecast will be the exact track of these systems, owing to the positioning of the Polar Vortex which is forecast to remain parked over Southeast Canada. This positioning allows for plentiful cold air, but also suppresses the baroclinic zone and favored storm track to our south. Forecast models, picking up on this and the southward sag of the arctic front, have trended farther south and east with the storm system forecast to track near the East Coast on Wednesday — the first in the parade. Currently, light snow still seems likely due to favorable jet streak positioning, but the heaviest precipitation is expected to remain offshore.

GFS model showing Wednesday's potential system passing mostly seaward.

GFS model showing Wednesday’s potential system passing mostly seaward.

Read more

Colder, more wintry weather set to return

It was a wonderful Saturday. High temperatures in the 50’s, plenty of sun and no precipitation to speak of. The first “winner” of a day in several weeks, in fact. The unfortunate news is that it won’t last long, and in fact the weather from Saturday will become a distant memory by the middle of the upcoming work week. The winter pattern, which dominated for the last month or two, will return — and remain relatively relentless.

Colder temperatures will begin filtering into the area by Sunday, as a frontal boundary nears the area. All won’t be lost, still, as high temperatures will reach back into the 40’s and 50’s just ahead of the front. But as the front nears, temperatures will begin to drop — and winds turn to a much cooler direction. By late Sunday Night into Monday, forecast models are in agreement that light precipitation will begin to develop just behind the cold front, beginning as rain and likely ending as snow in some locations away from the coast.

NAM model forecasting precipitation along a frontal boundary on Monday morning.

NAM model forecasting precipitation along a frontal boundary on Monday morning.

Read more

Milder air will give way to rain, storm threat

A relentlessly active pattern continues as we make our way into the latter half of February. Despite warmer air moving into the area on Thursday and Friday, a significant storm system in the Central United States will move northeastward towards the Great Lakes and drag a cold front through the area later on Friday. The weather on Thursday, in sensible terms, will be much milder than usual with temperatures both aloft and at the surface increasing and plenty of sun expected. We’ll consider it a bit of a consolation prize for the volatility of the pattern over the last several weeks. High temperatures are expected to reach close to 50 degrees in many locations (although cooler near the shore, as usual for this time of year) which will feel almost balmy compared to what we’ve become accustomed to.

Friday, however, looks to be another active weather day in the area with multiple hazards. First and foremost, the Storm Prediction Center has placed parts of Central and Southern NJ in a Slight Risk for severe thunderstorms. As mentioned above, a cold front will move through the area later on Friday. Increased forcing/lift along this front will act as an impressive trigger for storms — and southerly flow ahead of the front will likely provide adequate instability for at least elevated thunderstorms in those areas. A very impressive mid and low level jet just above our heads provides the potential for strong winds to mix down to the surface in any thunderstorms. Although widespread strong/damaging winds aren’t expected, a few severe gusts seem likely but will remain isolated. The threat drops off farther north where instability is less, although rumbles of thunder and heavy rain are still likely along the front.

Hazards overview for Friday, February 21 2014.

Hazards overview for Friday, February 21 2014.

Read more

You just lived through one of the snowiest periods in NYC’s history

Sounds dramatic. The response to the title of this article, from some, will likely be: “Well,  obviously.” But when you take a second to consider that we actually did live through one of the snowiest periods in the history of observed weather at New York City, it becomes fairly remarkable. The past 30 days or so have been nothing short of anomalous, with colder than normal temperatures (including a visit from an unusually impressive Polar Vortex) and well above normal snowfall throughout a vast majority of the forecast area.

The statistics don’t only confirm what we’ve known all along, they bring to the surface the reality of just how impressive the past month or so has actually been. The entire winter, in a certain sense, has been a giant anomaly — and it has been relentless. Things came to a bit of a head over the last 30 days, however, and our stats will focus on just how impressive the past month or so has actually been.

Snowfall by season in NYC, including 2013-2014 to date. Image courtesy Yehuda Hyman.

Snowfall by season in NYC, including 2013-2014 to date. Image courtesy Yehuda Hyman.

Read more