First Significant Nor’easter since November 2012

So, I’m going to be honest with you. When I saw the models trending towards the prospects of this storm, I was torn between thinking it was too good to be true and really wanting to see my first significant snowstorm since moving back to the Mid-Atlantic. We have even joked at work that the lack of snow this past two years is most likely due to my “stable dome of nice weather.” Then again, the tropics have been quite the uninvited guest since I returned, so I think there are people on both sides of this split-weather personality of mine that would like me to move. Be careful what you wish for. . .

Anyway, let’s get down to business. Yes, a storm is coming and looks to deliver some wet, heavy snowfall from the mountains of VA/WV into MD. The big questions I have are based on the possibility of more than 8″ of snow from DC through Baltimore to near the MD/PA border. I will be conservative to start with most places east of the Blue Ridge and along the I-95 corridor getting at least 8″, but my gut says this could be 12″ or more. I just can’t figure out if I want it to happen so badly that I’m defying logic. At this juncture, I don’t think so.

For NJ, Philly, on up to NYC, this is going to be even tougher. With easterly flow, I think most of the precipitation that falls will be in the form of rain, but as the deformation zone (cold side of the storm with heavy precipitation) develops and moves east, it will most likely change to snow all the way to the coast. I think you have a better chance of seeing accumulating snow (more than 1″) from Toms River on south, but if the storm turns more left or north, higher amounts will spread up the coast into New England, including NYC.

Sterling NWS snowfall accumulation forecast totals up to 1 pm Weds, valid on 3/4/2013.
Sterling NWS snowfall accumulation forecast totals up to 1 pm Weds, valid on 3/4/2013.
Mt. Holly, NJ NWS accumulating snowfall forecast totals through 7 am Thursday, valid on 03/04/2013.
Mt. Holly, NJ NWS accumulating snowfall forecast totals through 7 am Thursday, valid on 03/04/2013.

The two forecast snowfall accumulation maps above were issued by the Baltimore-Washington National Weather Service (NWS) and Mt. Holly, NJ NWS offices this afternoon. So far, they are in agreement with my initial thoughts, but I do think that areas along I-95 will see more snow above the projected 4″-6″. For NJ, there is more uncertainty with the exact path of the surface low and associated deformation zone.

18z NAM surface pressure and 60-hour accumulated precipitation valid at 1 am EST on 03/07/2013.
18z NAM surface pressure and 60-hour accumulated precipitation valid at 1 am EST on 03/07/2013.

For kicks, I included the latest (18z) NAM surface pressure and 60-hour accumulated precipitation forecast valid at 1 am EST on 03/07/2013 (Thursday). That is ~2″ of liquid equivalent over the DC-Baltimore corridor stretching to southern NJ with more precipitation after this stretching up through NYC and southern New England. If this verified, the DC-Baltimore area would stand the chance of receiving 12″-18″ of snow. NJ would get about 1″-1.50″ of rain followed by a thumping of snow at the end.

18z GFS forecasted surface pressure and 3-hourly precipitation forecast valid at 7 pm EST on 03/06/2013.
18z GFS forecasted surface pressure and 3-hourly precipitation forecast valid at 7 pm EST on 03/06/2013.

The 18z GFS forecast above shows a low position near the Delmarva coastline with a 996 mb surface pressure. Note the 1032 mb high to the north over eastern Canada. This difference in pressure will create a strong onshore flow from NJ on south to the MD coast. This could lead to minor-moderate coastal flooding, strong winds, and much aggravation for NJ, DE, MD, and coastal VA residents.

The bottom line. . .

Central VA: Expect rain slowly changing to snow with light accumulations around the Richmond area.

DC-Baltimore: Maybe, and I stress maybe, some rain to begin, but changing over to snow Tuesday evening. Accumulations starting out around 6″-8″, more to the west, less to the south. Would not be surprised to see areas along the I-95 corridor breaking the 12″ mark with the potential for thundersnow and strong winds. Power outages could be possible!

Coastal NJ: Rain to start and could get heavy at times, especially south of Toms River. Winds increasing to 30-40 mph with gusts 50-60 mph or higher. Coast flooding could be an issue with early estimates of 2′-3′, but check your local NWS office for more details. Rain could change over to snow later on Wednesday with a quick thumping of 1″-2″ possible. If the model trends continue north, then more snow will be possible.

Feel free to ask questions and thanks for reading!

2 thoughts on “First Significant Nor’easter since November 2012

  1. Love your prediction
    But why are most from local and national weather service predicting. 2 -3 or up to 5 inches only! For thr baltimore area, most if not keep big snow far west, and littel here and That’s too low for me

    What do u see happening?
    Please write back? Thank you

    1. Joe, the forecast totals are actually increasing as many of us get more confident. March snowstorms are tough to forecast due to the increasing strength of the sun and the fact that it’s getting “warmer”. Know that I could be wrong on this, but based on my experience, models tend to underwhelm snowstorms, especially in March.

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