Saturday 1 PM EDT
Sandy is still wobbling northward well off the South Atlantic coast. As a strong trough aloft approaches Sandy, the storm's circulation will be drawn into and become part of a greatly expanded upper air storm.
Since the storm will be a hybrid that includes some of the characteristics of the non tropical storms that cause most the cold season precipitation we see in the Great Lakes and Northeast, its circulation will be more spread out (rather than more compact). A lot of rain will be generated as tropically moist air is forced westward over air that is much cooler. This is something we typically do not see with pure tropical storms/hurricanes.
What all this means is that the heavy rain and increasing wind will reach places long before the center arrives. Delaware, New Jersey, as well as parts of eastern Pennsylvania and Maryland, are likely to start getting damaging winds and torrential rain tomorrow night, perhaps escalating into the worst conditions Monday morning. The center will come ashore after this, and by that time the rain and even the wind will be weakening.
Unless the storm tracks farther north than expected, the New York City area may be near the northern edge of the very worst conditions. Where the wind and rain are the worst, there will be streets flooded with water and massive tree damage and power outages. And, the wires have to be restrung one at a time... that's what takes so long (as well as other challenges of accessibility and maintaining safety.
It is important to complete your planning and preparation before the worst conditions approach later tomorrow. This video shows the situation and forecast as of early Saturday afternoon. Please check more recent information that will be continuously updated on AccuWeather.com. Also, your local emergency management people are trained on helping people avoid and deal with the most critical things that can kill and destroy.
Enhanced infrared satellite picture from early Saturday afternoon.
When we look more closely, we see a variety of disturbances embedded in the main current, each capable of temporarily increasing or cutting off the chance of snow. This map shows the setup:
This map shows the circulation around the offshore storm and a larger but less intense storm moving into the Great Lakes. With this sprawling storm likely to be in the region for several days, the weather can vary widely.
...speculation about a snowstorm Monday or Tuesday, and one is still possible. However, timing and placement remain elusive. This map shows the GFS ensemble mean "solution" for Tuesday morning showing snow just off the New England coast. Watch this story evolve on accuweather.com all weekend.
As we look father out this month, it looks cold for the Great Lakes and Northeast (as well as deep into the South) in the middle of next week but milder the following week. This map, for next Wednesday, shows a cold flow from way north in Canada.
A few tornadoes can also occur, especially from Mississippi and Alabama to Kentucky. This map shows the areas of potential severe weather through tonight as forecast by the NWS Storm Prediction Center.