Could this be a big snow?

I guess this depends on your definition of “big snow”.  Considering I had my biggest snowfall on 1/3/14, since moving back to the East Coast, this may pass that one by.  For most of my Mid-Atlantic to New England friends, this is a typical snowstorm that we just haven’t been able to get in the DC-Baltimore area for about 2-3 years.  So, what happened in the last 24 hours to go from flurries to several inches of snow?

GOES-13 water vapor valid at 0045 UTC on 01/21/14.
GOES-13 water vapor valid at 0045 UTC on 01/21/14.

The shortwave disturbance highlighted in the red circle is strengthening (amplifying) as it approaches the Mid-Atlantic tonight into tomorrow morning.  This will help a surface low strengthen near the Delmarva and with moisture increasing from the Atlantic, moderate to heavy snow will break out during the midday hours tomorrow from DC-Baltimore.  I anticipate a start time as follows:

DC-Baltimore:  8a-11a

Philly-NJ:  11a-1p

NYC-Long Island:  12p-2p

CT-MA:  1p-3p

The heaviest or most intense part of the storm is mid-aftn into the evening from south to north.  I will post the various National Weather Service forecasted snowfall amounts below, but here is my take:

DC-Baltimore:  6-9″ with some areas possibly seeing close to 12″

Philly-NJ:  6-8″ near Philly with coastal NJ coming in at 8-12″.  Now this is an average, but someone could get a bit more than 12″.

Northern NJ into NYC:  6-8″

Long Island, Rhode Island, and far southern Massachusetts:  10-12″ with some amounts closer to 15″

CT-MA:  6-8″, again with some areas closer to 10″

So, why the possible higher amounts?  There will be localized bands of snow that may even contain some thunder and lightning.  In these bands, you could get enhanced snow rates of 2″ or more.  It’s very hard to predict this ahead of time and becomes more of a nowcast challenge.

All areas will experience gusty winds (> 35 mph) in the late afternoon and overnight.  The coastal areas could gust over 4o-50 mph!!!  I would not be surprised to see at least coastal areas get upgraded to a blizzard warning, but it’ll be close.  Then comes the cold. . .we will probably go 3-4 days without breaking the 32 F mark, so get ready!

This pattern will continue to provide forecast challenges, so don’t be surprised if more snow chances pop up and surprise you!

Sterling NWS snowfall forecast for 1/21/14.
Sterling NWS snowfall forecast for 1/21/14.
Mt. Holly NWS snowfall forecast for 1/21/14.
Mt. Holly NWS snowfall forecast for 1/21/14.
Islip NWS snowfall forecast for 1/21/14.
Islip NWS snowfall forecast for 1/21/14.

 

Taunton NWS snowfall forecast for 1/21/14.
Taunton NWS snowfall forecast for 1/21/14.

I will update tomorrow as necessary.

Thanks for reading!

 

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