Forecast Snowfall Amounts Tick Up For Tomorrow

The below forecast update outlines timing and forecast accumulations for the upcoming storm.  A more detailed forecast has been prepared for Premium subscribers who similarly received an email summary outlining expected impacts and forecast risks.  To view the more detailed forecast and begin receiving email alerts and detailed storm forecast updates during any winter weather, subscribe here.  Otherwise, the free forecast is attached below.

FORECAST ACCUMULATIONS: Due to slight model trends north, I have increased forecast snowfall amounts: Areas north of I-84 see 3-7 inches of snow, with the higher amounts closer to the highway.  Inland portions of Fairfield and New Haven Counties see 4-8 inches of snow, again increasing in amount as we get close to the coast.  Inland Westchester and coastal Fairfield and New Haven Counties see 5-11 inches of snow, while southern Westchester may see 6-12+ inches.

Generally amounts were raised by 1-2 inches as weather model guidance has shown just enough of a northern trend for me to be concerned about higher amounts.  Some areas could see even more, as with these storms exactly where banding and the strongest convection sets up could make a huge difference.  It is worth noting that thunder snow will be a real possibility in some of the heavier snow bands, and that this could make amounts vary relatively widely.  Some region could also get briefly dry slotted as the storm will be going through rapid intensification.

FORECAST SNOW TIMING: With this slight northern jog we have also seen the timing of the storm get very significantly pushed up.  Snow will start from southwest to northeast sometime between 10 PM and 5 AM.  The precipitation shield will be extremely slow moving, so in northeastern New Haven County it could take even longer to fall.  Precipitation begins getting heavy by 7 or 8 AM it now appears, and should remain heavy with banding off and on through around 3 or 4 PM.  Following that, there will be some some scattered snow showers through the evening before snow finally winds down between 9 PM and 12 AM Sunday.

WINDS FORECAST: The latest GFS here show sustained winds approaching 25-30 mph at the coast tomorrow morning around 10 AM with gusts to 45 mph.  I still struggle to see gusts even at the immediate coast getting much higher than that as the strongest winds and most of the worst impacts are across New Jersey.  Storm surge will not be as bad here here due to the storm positioning and more rapid intensification further south allowing the storm to wander off a little more to the east.  Inland wind gusts only get to around 35 mph, which will still be blustery with periods of heavier snow of course.  Winds peak in intensity between 7 AM and 1 PM and die down through the afternoon.

Overall, though, uncertainty continues to run extremely high.  The SREF mean here calls for widespread snowfall amounts of 12-20 inches across the region, with the NAM and other short-range guidance in agreement.  I still do not totally buy it, but again it is really something to watch for as there is a chance that amounts come in higher than I am forecasting with these small shifts.  Similarly, Canadian guidance continues to show accumulations in the lower range of the going forecast, adding confusion.  I may adjust accordingly with a late night Premium update tonight but will continue watching short-range guidance come in to see what to do.

In summary, avoid travel through the day tomorrow, as whether we get 6 or 12 inches of snow travel will be treacherous on snow-covered roads with gusty winds.  We clear out early enough Saturday evening that by Sunday things should be improving. Another Free update will be posted should the timing or accumulation be adjusted ahead of the storm.

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