Wednesday, February 3, 2016

The Great Northeast Snow Meltdown: From Winter Storm Jonas to Bare Ground In Less Than Two Weeks

Jon Erdman
Published: February 3,2016

A little more than week ago, Winter Storm Jonas was the heaviest snowstorm of record for over a handful of Northeast cities.
(JONAS RECAPS: A Record Setter | News Recap)
Incredibly, except for some crusty, dirty snowpiles left over from snowplows, the ground will be largely bare by late this week.
NOAA calculated Winter Storm Jonas blanketed about 434,000 square miles of the mid-Atlantic and Northeast with snow, with almost 24 million people from eastern West Virginia to western Long Island experiencing 20 inches of snow or more.
(MORE: Jonas a Category 4 Winter Storm)
While morning lows were quite cold, thanks in part to the fresh, snow cover, since Jan. 24, daytime highs above freezing, and a warm spell heading into February, withered the hefty snowpack.
Animation of snow depth from January 24 through February 2, 2016 in the mid-Atlantic states.































For instance, Washington's Dulles International Airport set a record snow depth in their 54-year history after Winter Storm Jonas, with 28 inches of snow on the ground January 24.
One week later, they topped out with a high of 60 on Jan. 31, then after topping out in the mid 50s Monday and near 50 degrees Tuesday, Dulles' snow depth early Wednesday was down to a mere 1 inch. That's melting 27 inches of snow in roughly ten days.
Similarly, New York's LaGuardia Airport melted 27 inches of snow in nine days.

LaGuardia's Snow Meltdown (Jan.-Feb. 2016)

024681012141618202224260491317222631353944485257Jan. 24Jan. 25Jan. 26Jan. 27Jan. 28Jan. 29Jan. 30Jan. 31Feb. 1Feb. 2Snow Depths (inches)Daytime Highs (˚F)
Snow Depths (inches)
Daytime Highs (˚F)
Data: National Weather Service; Graph: weather.com/Infogr.am

This may sound like an impressively fast snowmelt in the middle of winter, but it's happened before several times.
Using Washington's Dulles Airport as an example, here are four relatively recent examples of rapid snowmelts of impressive snowpacks:
  • 23 inches in six days:  Jan. 13-19, 1996
  • 22 inches in seven days:  Feb. 19-26, 1979 (following the "original" Presidents' Day snowstorm)
  • 22 inches in 11 days: Feb. 12-23, 1983 (following the "Megalopolitan" snowstorm) 
  • 26 inches in 16 days: Feb. 10-26, 2010 (following the twin "Snowmageddon" snowstorms)
In short, sometimes the cold pattern that locked a heavy snowstorm into the mid-Atlantic states flips in the matter of 1-2 weeks, bringing either a thaw or a soaking of rain.

Rain Ahead Will Melt What's Left

The area of low pressure associated with Winter Storm Kayla tracked into eastern Canada Wednesday which means most of the Northeast, including all of the areas swamped with snow from Winter Storm Jonas, saw rain this time.

Northeast Rain/Snow Forecast
Some areas may pick up over an inch of rain before the cold front clears the Northeast seaboard by later Thursday.
This, combined with snowmelt could lead to some flooding of small creeks, streams, low-lying and poor-drainage areas.
(MORE: NWS Current River Stages and Forecasts)
Flood watches have been posted in parts of the mid-Atlantic states.
The National Weather Service in Mount Holly, New Jersey, mentioned in their flood watch issued Tuesday morning that some road closures are possible late Wednesday into Thursday near any flooded areas. Generally minor to moderate river flooding was possible in the Raritan, Passaic, and Schuylkill Basins, according to the NWS.

MORE: Winter Storm Jonas Photos (Jan. 2016)

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