Thursday, February 7, 2013

Historic Blizzard to Impact All of southern New England 2/8-13-2/9-13

Computer model guidance continues to be in major agreement that an historic blizzard will have extreme impacts on all of southern New England as a long duration event is a little less than 24-hours away from unfolding.  This storm will have the potential to dump 1.5 to 2 feet of snow region wide along with the possibility of up to 3 feet of snow for some.  We will also be experiencing strong/damaging winds leading to blizzard conditions and whiteout conditions at times, widespread power outages, especially with the weight of snow on tree limbs and power lines, extreme coastal flooding, and the possibility of thunder/lightning.  This will also be a life threatening situation for the homeless and anyone who is trapped outside.  Below we will look into all the hazards associated with what looks to be an historic blizzard.

-Potential for Substantial Snowfall Accumulations Region Wide.

Computer model guidance is in major agreement that we will be seeing substantial (widespread 12''+) snowfall accumulations region wide as many places will pick up as much as 18-24'' of snow.  In fact, we could be looking at as much as 24-30'' of snow for quite a few with even some spots getting as much as 36''.  This will be a fairly slow moving storm and it's associated with a great deal of moisture, with moisture being fed into the storm from both the Gulf of Mexico and the Atlantic Ocean.  There will be a vigorous amount of lift associated with this system along with excellent snow growth.  All of these factors will lead to very heavy snowfall rates with rates as high as 2-4''/HR, especially if there is any thunder/lightning associated with the heavier bands.  Snowfall ratios could also be as high as 13:1 to 15:1, especially across the interior away from the coast.

-Potential for Strong/Damaging Winds Region Wide

With the storm undergoing rapid intensification and a large pressure gradient developing over the region we will see a major increase in the winds, especially out across far eastern MA/Cape region.  Here we could be looking at a prolong period with winds sustained as high as 45-60 mph with wind gusts as high as 75-85 mph.  This is equivalent to category 1 hurricane force winds.  With substantial snowfall accumulations out across this area and snow sticking to tree limbs and power lines widespread power outages can be expected with the possibility for power outages to last for several days.  Elsewhere across southern New England, we are looking at the possibility for sustained winds of 25-35 mph with wind gusts as high as 55 mph.  This, along with substantial amounts of snow should lead to widespread power outages as well with some of the outages lasting for several days.  These winds will lead to a several hour period of blizzard/whiteout conditions making visibility values close to 0 at times.  This will make travel extremely difficult and very life threatening.  Travel during the storm is strongly not recommended.  Strong winds will also lead to drifting snow and we could see snow drifts as high as 4-6 feet!

-Potential for Extreme Coastal Flooding

With such an intense storm system just off the coast and an easterly component to the winds this will lead to extreme coastal flooding across the east facing shores of the ocean across eastern MA/Cape.  Currently we are in a new moon phase so high tides will be running much higher than average and high tide will be occurring during the height of the storm.  This could pose a life threatening situation to anyone near the immediate coast, especially if you're outdoors.  Looking at wave heights as high as 7-10' and perhaps a bit higher.

-Potential for Thunder/Lightning

With such a strong system and vigorous lift associated with it, the possibility of thunder/lightning is possible with this system.  If there is any thunder/lightning that would locally lead to snowfall rates as high as 4'' per hour.

-Storm Timing/Travel Hazards

As the morning hours progress on Friday we should see periods of snow showers as an initial piece of energy moves overhead.  It's possible that these snow showers could lead to a quick coating or an inch for some but the brunt of the storm starts occurring during the early to mid-afternoon hours and then conditions will rapidly deteriorate.  Throughout the duration of the storm travel is not recommended at all as this will be a very dangerous storm and anyone caught or trapped outside could be in a life threatening situation as it could take a while for safety officials to reach you.  Plows will have a very difficult time keeping the roads clear, given snowfall rates could exceed 2-4'' per hour.  The snow should begin winding down sometime late morning Saturday with on and off snow showers the remainder of the afternoon, especially across eastern MA.

This is a very dangerous and perhaps life threatening storm for anyone who risks travel.  We are looking at the possibility of an historic storm with substantial snowfall totals, strong/damaging winds/widespread power outages/extreme coastal flooding.

Below is the snowfall map:

Below is Wind Forecast: