Updated Snowfall Forecast 02/17/2018 into 02/18/2018

No big changes to yesterday's forecast, however, forecast models have become a bit more aggressive with total precipitation accumulation across the state thus have decided to increase snowfall totals for northwestern CT. There are some indications that the immediate shoreline will see warmer air towards the surface work in thanks to a developing southerly flow transporting warmer air off the ocean so this will work to keep snowfall totals down here. However, with this influx of warmer air, this will make for snow to be on the wet side across these areas and this could result in some pockets of power outages. While the atmosphere is rather dry right now, forecast models indicate we will saturate rather quickly and because of this the timing of the onset of the snow may be on the earlier side.

Forecast models continue to indicate a several hour period of very intense upward vertical motion moving over the state and there are strong indications that the maximum degree of frontogenesis will coincide with maximum upward vertical velocities. This coupled with excellent snowgrowth and strong upward vertical motion and moisture within the snowgrowth zone will result in a several hour window of moderate to heavy snowfall. This window should be from 11:00 PM this evening to 4:00 AM tomorrow morning. During this time snowfall rates will approach or perhaps even briefly exceed 1.5'' per hour. It will be during this period where the majority of the snowfall accumulations will occur. The latest run of the European forecast model drops upwards of 0.5'' of liquid equivalent over much of CT during a 6-hour window which suggests very heavy precipitation falling and this precipitation will be in the form of snow. Computer forecast soundings also show modest instability within the 700mb-500mb level which further indicates the likelihood for moderate to heavy snows.

What to expect:

• Snow begins to breakout between 7:00 PM and 9:00 PM. 
• Snow quickly begins to increase in intensity with the heaviest snows falling between 11:00 PM and 4:00 AM. During this time snowfall rates may approach or exceed 1.5'' per hour. 
• While snow will be on the fluffier and lighter side across inland Connecticut, closer to the shore were warmer air will work in, this will allow for snow to be wetter and heavier. This could result in some isolated pockets of power outages.
• There is the possibility for a few towns to receive upwards of 9-10'' of snow, however, due to the very fast movement of this storm those amounts are not expected to be widespread.
• Snow begins to wind down after 4:00 AM and will be out the state by 7:00 AM, however, some leftover flurries may remain across eastern CT. 
• Below is the updated snowfall map: