Friday, February 8, 2013

Historical or Hysterical?

The nor'easter now intensifying out over the Atlantic has received a lot of news coverage the past two days, well before the first snowflakes or rain started to fall from this system. That is in part a testimony to the sophistication of weather forecast computer models which are able to tip off meteorologists sometimes days in advance to the development of these storms.

Is the designation of this storm as potentially "historical" just hype?  Based on the forecast path, intensity, and duration of the storm, it does have the potential to be one of the most impressive and damaging nor'easters in the past 30 to 40 years. The storm to beat, so to speak, is the Blizzard of February 5-7, 1978, 35 years ago to the week.

Here is the snowfall from that storm.

Here is the forecast snowfall for this week's storm.

The winter of 1977-1978 was epic across the eastern two-thirds of the country, characterized by numerous storms and record snow and cold.

Temperature and snowfall for the winter of 1977-1978

The Northeast and New England had already been hit by nor'easters that winter, but the February 5-7 storm was in a class of it's own.  There were a number of factors that combined to make this storm one for the record books.
  • Strong high pressure stationary over Greenland acted as a block to stall the storm off the coast of Southern New England for 36 hours.
  • Astronomical tides were high in early February, and a long fetch of northeast winds increased tides even more. Tides were about four feet above normal, and storm-generated waves reached 12 feet on top of the tide. Coastal areas experienced damaging high tides for four tides cycles during the course of the storm.
  • Snowfall amounts exceeded 3 feet. Woonsocket, RI had 38.0 inches, Rockport, MA - 32.5 inches; Providence, RI - 27.6 inches, and Boston, MA - 27.1 inches. The highest unofficial snowfall measured was 55 inches at Lincoln, RI. Drifts were reported as high as 27 feet.
  • Hurricane-force wind gusts were recorded, with Boston recording a gust of 79 mph and Chatham. MA a gust of 93 mph.
  • The storm lasted 36 hours.
  • 99 people lost their lives, and damages were estimated at $1 billion.
The February 5-7 blizzard was well-forecast, and warnings for blizzard conditions were issued 15 hours ahead of time. However, a few other storms, particularly an earlier nor'easter on January 19-21, were poorly forecast, and people were skeptical of the warnings. Many were caught out because they did not heed the warnings, and because the snow started somewhat later than originally forecast.

The National Weather Service in Taunton, MA has prepared an excellent summary of the Blizzard of 1978, The Blizzard of ‘78…Revisited.  There is information on the synoptic setup, statistics, photos, and comparisons to more recent winter nor'easters. 

CoCoRaHS observers in the storm area are encouraged to submit Significant Weather Reports during this storm.  Stay safe!

You can follow information on this storm on the NWS Eastern Region Facebook page.

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