I would normally have made a forecast map for an event of this magnitude, but I haven’t had the time. I will, however, post a short forecast discussion regarding the second major snowstorm to impact New York and Boston with likely 12+” totals in under three weeks.
This morning, moderate to heavy snow and freezing rain continue to impact parts of the southeastern US in association with a low pressure system along the Gulf Coast. As this storm throws warm moist air from the tropics into a preexisting cool air mass, places from Atlanta, GA to Shrieveport, LA are beginning to dig out from an unusually bad I-20 ice and snow event (as much as 6 inches of snow has fallen in northern Alabama and Georgia). This system is weakening as is expected to all but dissipate today. However, it leaves behind a region of tropical moisture content and has set the stage for an I-95 corridor snowstorm to impact all of the major cities of the megalopolis.
That event will begin as another storm dives into the Mississippi Valley tonight. This upper level low has caused some bands of heavy snow to break out this morning in the Central Plains and that snow will spread East today into the Mississippi and Ohio River Valleys before weakening as it approaches the Appalachians. This feature will weaken and transfer its energy to the coast near the mouth of the Chesapeake Bay, helping to form a new coastal storm tonight. As it does, light snows will overspread the DC and Baltimore metro areas after sunrise Tuesday. Those snows will continue to expand and intensify as the storm lifts NNE along the wall of the Gulf Stream and eventually to near 73 W and 40 N (about 50-100 miles SE of Montawk Point, NY) before fading ENE. Some uncertainty remains regarding the exact track of the storm and small shifts in that track may cause big changes in snowfall totals as the storm acquires some warm cored characteristics and develops a band of heavy snow to its’ north and west.
That snow band may carry 2-4 inch per hour snowfall rates, winds in excess of 30 mph, and near whiteout conditions Tuesday Night and early Wednesday Morning as it lifts through Long Island and Southern New England, tapering off in Boston by early in the evening Wednesday.
Current snowfall estimates for the big cities and nearby suburbs from this storm:
Richmond, VA: Dusting to 1″
Charlottesville, VA: Dusting at most
Washington, DC: 2-4″
Baltimore, MD: 3-6″
Dover, DE: 4-8″, lower amounts if rain/sleet mix in
Philadelphia, PA: 6-10″
State College, PA: 4-8″
Trenton, NJ: 8-12″
Atlantic City, NJ: 6-10″
Newark, NJ: 10-14″
New York City, NY: 10-14″
Brookhaven, NY: 14-20″
Montawk, NY: 12-18″ with sleet and/or rain mixing in
Hartford, CT: 10-14″
New London, CT: 14-20″
Providence, RI: 18-24″
Boston, MA: 18-24″
Worcester, MA: 18-24″
Cape Cod, MA: 8-12″ changing to rain
Portland, NH: 18-24″
Stay tuned…I’ll score those forecasts after the event passes!