Thursday, January 4, 2018

Winter Storm Grayson

It sounds like a name from a Jane Austen novel: Winter Storm Grayson.

Winter Storm Grayson will undergo bombogenesis off the Eastern Seaboard into Thursday, becoming an intense ocean low producing heavy snow, blizzard conditions, damaging winds and coastal flooding in New England.

Blizzard warnings have been posted for much of the coast from Maine to far northeastern North Carolina, including Boston, Portland, Maine, Atlantic City, New Jersey, and Norfolk, Virginia.

Winter storm warnings have been issued to the west of the blizzard warnings, including much of the Interstate 95 Northeast urban corridor from Maine to Delaware. This includes New York City and Philadelphia.

Low pressure well off the Southeast coast will track north-northeast off the Eastern Seaboard and explosively intensify through Thursday, before plowing into Atlantic Canada Thursday night into Friday.

Areas in light blue denote snow. Pink and purple areas denote sleet or freezing rain. Areas in green, yellow, orange or red denote progressively heavier rain.

This explosive development is what meteorologists call bombogenesis, defined by a rapid drop in atmospheric pressure of 24 millibars or more in a period of 24 hours.

In this case, according to NOAA’s ensemble tracks forecast, Grayson’s central pressure could drop roughly 45 millibars in 24 hours ending Thursday evening just off southwestern Nova Scotia.

Not only would this be one of the most rapid rates of bombogenesis associated with an East Coast storm, but its central pressure may bottom out in the 950s millibars, also among the strongest offshore storms you’ll see.

Yeah, this is the subzero equivalent, at least in terms of threats to life and property, of a hurricane.  Take it very seriously.