Month: January 2017

Beginning later tonight through Tuesday morning, our area will be impacted by a strong Nor’Easter. Winds will begin to pickup later this afternoon into tonight. Additionally, there may be some light rain in the area this afternoon and tonight. By tomorrow morning winds will be gusting over 30-40mph. The core of the storm will impact the area later tomorrow afternoon through early Tuesday morning. During this time, we can expect to see sustained winds over 50 mph, with wind gusting over 60mph. It is possible that within strong thunderstorm cells (yes thunderstorms) that winds may gust over 70mph or more. Below you will see on the maps that winds just above the surface will be over 70mph during the height of the storm. In regards to rain, we can expect somewhere between 1-2inches of rain, and possibly more if a strong thunderstorm passes over your area.

Overall, this is shaping up to be the strongest Nor’easter that the region has seen in a long time and has the potential to cause significant property damage and power outages.

Note that 925MB is about 2,000 feet above the surface

Gif courtesy of stormvistawxmdoels

Models this morning have trended slightly North with precipitation related to a wave of low pressure passing South of the area. What this means for us is a chance of some light snow after 4PM today. By the time the low moves out late tonight, we could have a coating to an inch on the ground. 

Overall this will be a low impact event. 

Don’t look now, but the HRRR/GFS/RGEM just came in and they all have increased the precipitation that we can expect in the region. At this point in time, 8 inches of snow is looking more possible. Therefore, I am now increasing the forecast for Nassau to 4-8 with an outside chance of may even 10 though I doubt it at this time, and NYC to 3-6.

Tonights model runs continue the theme of a moderate snowfall for the region tomorrow. The snow will overspread the region between 8 and 10 am tomorrow. It will continue throughout the day, heavy at times. Snow should begin to taper off sometime between 5 and 7PM tomorrow evening. Most models have come into agreement that snowfall will be somewhere in the 3-6″ range. However, I caution that we could see up to 8″ depending on ratios. (Usually we calculate 10:1, 10 inches for every inch of liquid, but when it becomes extra cold in the atmosphere this can go up to 15:1 or 20:1).

The further East on Long Island you are, the more snow you will see. The East End may every well see a foot of snow by the time the storm pulls away. For NYC you can expect about 2-4″, but the ratio comment above applies to NYC as well.

Here’s a current summary of liquid amounts that models are showing in NYC (Remember multiple these by 10/12/15/20 to get actual snowfall amounts). These liquid amounts increase as you go further East:

SREF:  0.45
NAM (regular): 0.35- 0.45
NAM (Hi-Res): 0.4-0.5
GFS: 0.10 – 0.15
RGEM: 0.40 – 0.45
GGEM: 0.30 – 0.35

The most recent model runs continue to trend towards more snow. The RGEM which is considered decent in the short range placed our region solidly in the 3-6/4-8 range. This aligns fairly well with the HiRes NAM model. The GFS continues to show less than both these models but has also trended towards a more significant storm.

Overall, we can expect snow to start mid morning and continue throughout the day. I will provide a late night update tonight and early morning update tomorrow. This is truly a nowcast type storm.

Total snowfall expectations:

• Nassau and Western Suffolk: 3-6 inches with more possible depending on track.
• Mid-Suffolk to the East end: 4-8+
• NYC: 2-4