‘Textbook’ Snowpocalypse: Major East Coast shut down?

East Coast weather 'event' likely 

At least it's hitting on a weekend.

A textbook major East Coast winter storm looks increasingly likely to achieve the early pre-storm hype. All the major ingredients for crippling snowfall totals of 1 to 2 feet or more seem to be coming together with each passing forecast model run. This looks like the biggest winter storm of the season for the East Coast, and it could challenge some snowfall records for major east coast cities.

Here's the developing system. A relatively moderate low pressure center crosses the Mississippi River Valley and drops into the Deep South, preparing for intensification before tracking northeast along the coast this weekend. Note how the southerly flow ahead of the storm pre-loads deep Gulf moisture into the system even before it hits the Atlantic.

Big snowfall totals?

Take one part Arctic air to the north, one intense low pressure bomb and a warm Atlantic moisture source and what do you get? Some incredible snowfall total projections. The track of the storm is still in flux, and a change of 50 to 100 miles still could make a huge difference in snowfall totals at any one spot.

That said, the likelihood of heavy, even crippling snowfall for several majors east coast cities is growing. Washington, D.C., Baltimore, Philly, and New York could all be in virtual shutdown-mode this weekend.

Again, it's still early. But the model averages for Washington, D.C. are running between 15" and 25" with this storm.

Top 10 snowfall event for Washington D.C.?

Again it's too early to be precise. But the modeled snowfall totals of 15"+ would crack the top 10 all time snowfall events in D.C. and 20"+ would be #2.

Hurricane-force storm surges?

Snow totals will get a lot of headlines with this storm as usual. But one of the most damaging aspects of this winter mega-storm will be several hours the combined effects of near hurricane force wind gusts, 2- to 5-foot storm surges and 20 to 30 foot waves pounding the east coast. Tightly packed isobars on the northern side of the advancing deep low pressure center produce a core of sustained high winds along the Jersey coast and Long Island.

The hurricane force wind gusts will combine with full moon high tides to drove storm surge to major levels along the coast this weekend. Moderate to major flooding is expected at high tide this weekend in coastal New Jersey.

The easterly fetch into Long Island Sound is a concern. That's the scenario that produced severe flooding in Hurricane Sandy. This storm will likely not reach Sandy surge levels, but it could challenge Irene's 5-foot storm surges in NYC.

As you would expect, several east coast NWS offices are on high alert well before the storm.

Here's Baltimore/Washington, D.C.

Philly.

NYC.

All signs say this is going to be the big one back east this winter. Stay tuned.