Friday 9 AM
Sandy continues to threaten the Northeast, and in the area where is comes ashore, there will be damaging winds knocking down trees and cutting power, flooding rain and, at the coast, a dangerous storm surge. Time of that is crucial, because we will be close to the time of the full moon, and range between high tide and low tide is greatest then. This map shows the track forecasts of a wide variety of computer models. Why the differences? Each one has its own way of ingesting data and handling the intricate math associated with second order nonlinear differential equations. A big problem is we simply do not have data for every place in the atmosphere.
This video discusses where the storm is heading now, what should happen next, and what some of the effects will be. Unfortunately, this kind of storm can affect millions and cost billions.
That could lead to tough travel at the end of the weekend. This map for Sunday at 7 p.m. ET shows where those troubles could be (north of the line with the label "snow rain line.")
This table shows the ensemble means for the next two weeks at Philadelphia: It suggests that whereas it does turn cold, any snowfall looks quite limited.
It is too early to be confident about any forecast for Christmas Day (or even the week before). However, the GFS model does go out 16 days, and it has a cold look for the Northeast exactly one week before Christmas.
As the flow aloft becomes southwesterly, mild moist air will spread northeastward from the Gulf States. In summer, this creates a hazy, very warm and humid scene for the Northeast. Now though, the warmth is slowly drained away as the moist mild air advances over cold ground. With temperatures near the saturation point, clouds form.
If each one of us lights an inner flame for just one thing- just one aspect of our lives we are thankful for, the warmth we create can light the world on Thanksgiving. The flame of warmth and love can burn so bright that no cold wind on earth can blow it out.
One concern for later this afternoon and evening is a trailing batch of precipitation moving northeast from the Carolinas. If this survives to reach the I-95 corridor just as the cold air arrives, there could be a brief but nasty episode of snow that makes it slippery.