3:58PM
First off, let me wish all of you a happy and healthy 2014! Thank you for being part of this blog!
Several days ago, I indicated concern about the period of January 2-4 for a potential winter storm event of some sort, and as would be expected, it was far too early to say much more than that. As much as we’d love to think these things come into focus quickly, they simply do not, given the level of technology available to us. Even at this stage with details much more clear about the event, there are still unknowns that leave us with a forecasting challenge. The details may be more minute, like for example which towns will get over a foot of snow because ocean enhancement and which will not, but nevertheless they remain less than 100% clear. There is always going to be uncertainty built into any forecast. It’s the core of the definition of inexact science given to the term “meteorology”. But with that challenge in place, it’s still not going to deter us from trying to understand it. Now it’s time to “apply the try”.
The storm: It comes in 2 parts, the first a strip of energy that comes in from the west and a developing surface low moving along an Arctic boundary south of New England, delivering light to occasionally moderate snow from the early hours of Thursday into Thursday evening with a few to several inches falling across the region during this time. The second part will be a hang-back piece of energy spawning a stronger surface low pressure area that passes just a little closer to the region later Thursday night and early Friday. All the while, a sprawling Arctic high pressure area will be in place across extreme northern New England and southeastern Canada, supplying not only very cold air for the storm to be in the form of fluffy snow, but also a pressure gradient and a moderate to occasionally strong northeast wind, adding Atlantic moisture to the system. This will enhance snowfall especially over eastern MA where the highest totals will likely be realized. All of it winds down and comes to an end during the day on Friday, but winds will increase and shift more to the north, pulling pure Arctic air into the region, as well as blowing the snow around during the after the snowfall, reducing visibility significantly at times. Occasional blizzard conditions are not out of the question. When the snow is done falling, expect total accumulations for the entire event to be in the 7 to 14 inch range in most of the region. However, a few lower totals may occur on the South Coast and over Nantucket, and bands of higher totals may take place near the eastern coastal areas of MA due to ocean enhancement. It is too early to say exactly which communities will see the highest totals. This is something best figured out as the event unfolds. Truth be told, anything in this range won’t make much difference because there will be considerable blowing and drifting of snow. The benefit of having snow with such cold air around is that the very low water content of the snow will make it much easier to move (though the wind will counteract some of our efforts to move it). Total snow accumulation that I expect: 7-14 over most of the region, with a few lighter amounts South Coast and Nantucket, and locally higher amounts possible in parts of eastern MA due to ocean-enhanced snowfall. Watch for minor coastal flooding at times of high tides, especially around midnight Thursday night for east-facing shores and midday Friday for north-facing shores.
The cold: The deep freeze arrives during the storm and remains in place into Saturday. Winds will remain quite gusty, so air temperatures in the single digits above and below zero across the region Friday night and early Saturday, combined with the gusty wind, will drive wind chill values to dangerously low levels.
The moderation: Daytime Saturday will remain very cold, struggling to reach 20, but by Sunday expect it to moderate at least to 30 if not above, ahead of the next weather system.
The next system: There are some uncertainties due to varying guidance, but for the time being I will go for a fast moving system heading northward, passing just west of New England Sunday night and Monday, then dragging a cold front through here. It may warm up significantly as this system makes its approach, then likely turn dramatically colder as it drags a cold front across the region at its conclusion.
Cold again: A fresh batch of Arctic air is likely to arrive behind the Monday system, turning it very cold again for Tuesday and Wednesday of next week.
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Updated forecast for southeastern New England…
TONIGHT: Clouding up. Snow developing west to east before dawn but only minor accumulation at most (less than 1 inch). Lows 12-17. Wind light NE.
THURSDAY: Overcast. Snow much of the time, light to moderate in most areas, accumulating up to a few inches during the day. Highs 18-23. Wind NE 10-20 MPH.
THURSDAY NIGHT: Overcast. Snow, light to moderate early, moderate to at times heavy later, accumulating several inches during the night. Blowing and drifting snow. Lows 7-12 except 12-17 South Coast. Wind NE 15-25 MPH gusting 30-40 MPH. Wind chills around zero.
FRIDAY: Overcast with snow in the morning, tapering off from west to east with time, but accumulating a few more inches (see above for storm totals). Breaking clouds afternoon. Blowing and drifting snow. Temperatures steady 7-12 except 12-17 south Coast. Wind NE to N 15-35 MPH. Wind chills often below zero.
SATURDAY: Mostly sunny. Lows -10 to 0. Highs 15-25.
SUNDAY: Mostly cloudy. Lows 5-15. Highs 32-42.
MONDAY: Mostly cloudy with rain AM. Breaking clouds PM but chance of rain showers then snow showers. Temperature rise to 45-55 morning, fall to 30s afternoon.
TUESDAY: Partly cloudy. Chance of snow showers. Lows 5-15. Highs 15-25.
WEDNESDAY: Mostly sunny. Lows -5 to 5. Highs 15-25.