October Snow!!!!

Ok, so I’m going to be honest with you. . .when I first saw the possibility of snow being trumpeted by some bloggers in the private sector, I thought. . .yeah right. It’s October! Snowfall this time of year in the Mid-Atlantic and Northeast is rare, though far from impossible. October 10, 1979, while the Orioles were playing the World Series (yes, that did happen once. . .), 0.3″ of snow fell at BWI, DCA, with 1.3″ reported at IAD or Dulles International Airport. Snow this year has had an early start with light accumulations seen a couple weeks ago in the WV and western PA mountains. Even last night, snow flew in upstate NY and NH with many power outages experienced. Earlier this week, many of us saw the pictures of snow in Boulder and Fort Collins, CO. This could be a precursor of things to come. . .

This is starting to look like an impressive coastal storm with wind and rain/snow being the biggest issues. Coastal areas could experience wind gusts over 50 mph and Gale and Storm Warnings are already posted offshore. I would not be surprised to see winds gusting over 60 mph in isolated spots by Saturday evening.

As for the storm evolution. . .below are 6 hourly increments of the 12z GFS

12z GFS precipitation accumulation and sea level pressure valid at 2 p.m. EDT on 10/29/11.
12z GFS precipitation accumulation and sea level pressure valid at 8 p.m. EDT on 10/29/11.
12z GFS precipitation accumulation and sea level pressure valid at 2 a.m. EDT on 10/30/11.

And here is the 18z NAM

18z NAM precipitation accumulation and sea level pressure valid at 8 p.m. EDT on 10/29/11.
18z NAM precipitation accumulation and sea level pressure valid at 2 a.m. EDT on 10/30/11.

Both solutions show cold air draining south as the precipitation intensity increases tomorrow afternoon from DC up through NYC. A quick look at the European model confirms this as that model has been consistently calling for snow in many areas for about 4 days. So what does this mean for those that will be affected?

Sterling, VA National Weather Service (LWX) snowfall accumulation map as of 6:20 p.m. EDT on 10/28/11.
Mt. Holly, NJ National Weather Service (PHL) snowfall accumulation map as of 6:20 p.m. EDT on 10/28/11.

As you can see above, both snowfall maps are rather impressive for this time of year. The heaviest accumulations will be in the Blue Ridge, Alleganies, up through Allentown, the Poconos, and Catskills. Although the maps say anywhere from 6″-10″, it’s possible some areas see over 12″-14″. Closer to the cities, I would expect up to 2″ maybe 4″. Along the coast, it’s a tough call. . .when the rain changes to snow as it should in most areas, it will snow very hard for a couple hours. That could lead to 1″ maybe 2″ along the coast of NJ, but I’ll have to see how this plays out tomorrow. This is a bold forecast and much can still go wrong, but for snow lovers. . .this is a nice early treat. Interesting to note. . .the Northeast and Mid-Atlantic experienced a very powerful storm 20 years ago this weekend (the Halloween storm, better known as the Perfect Storm). Strange timing, huh?

Finally, be aware that if you see a good amount of snow, trees will fall down under the weight of the snow as many trees still have most of their leaves. This will be a high ratio snow. . .5:1 or 8:1 at best, so it’s heavy, wet, gloppy snow. Roads should be mostly fine as they are still warm and overall, this will melt rather fast with temperatures rebounding by Monday. I do expect many power outages between the heavy snow on trees and power lines as well as high winds during and after the storm passes with the pressure gradient.

Try to enjoy this storm as it’s a very rare event!

Thanks for reading!

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