Sandy is Coming!

There is no doubt about it now. Sandy is going to make landfall somewhere in New Jersey late tomorrow night. And she will be a monster of a storm, packing a central pressure somewhere in the 940-950 mb range. Where we had no model consensus earlier this week, we now have an almost unanimous landfall location.

So lets get right to it, what can we expect?

Rainfall- This won't be a huge rainmaker for those of us in Southern New England. I expect some showers to break out as early as this evening, but the bulk of the moisture should hold off until about 5-8AM tomorrow morning. Expect heavy rain through Monday night and Tuesday morning with totals ranging from 1-3 inches. Nothing drastic, but when the rain does fall, it will be heavy. Nothing compared to the totals the mid Atlantic will see. Check out some of those totals below.

Wind- This will be the biggest impact of Sandy for us. I know that it must be hard to understand, since Sandy is clearly making landfall well to our south. For most tropical systems, this landfall location would spare us any real wind damage. But as I have said again and again, this storm set up is like nothing we have seen before. Sandy's strongest winds are actually going to be break away from her center and pivot up into Eastern and Southern Massachusetts. Her wind field is going to become MASSIVE as well, with sustained tropical storm force winds extending some 300+ miles from her center in both directions!   So here are some numbers. Winds are already picking up this afternoon. By Monday morning, sustained winds in Boston will be on the 25-45mph range, with stronger winds along the coast and south to the Cape. By about 1 or 2 pm, we are expecting the strongest gusts to begin to effect our area. From Monday afternoon into Monday evening, sustained winds in Boston will be 30-50mph, with frequent gusts of 65mph+. This will be an extremely dangerous time, where I suspect most of the power outages and wind damage will occur. Along the south shore and on Cape Cod, Monday afternoon will feature sustained winds of 50-65mph with frequent gusts of 75mph+! It goes without saying, that this figures to be the most destructive time frame of the storm. I have to mention the very real possibility of some gusts over 100mph in extreme southern Mass and Cape Cod. Take a look at the projection of wind speeds at 1000 feet above surface for tomorrow afternoon. That maroon area over Cape Cod indicates wind speeds of 90-100knots (103-115mph!) which could very easily mix down to the surface in an isolated gust. Just one gust of that strength would be devastating.

Coastal Flooding- This will be a concern for coastal areas over about 3 high tide periods, Monday in the afternoon, Monday at midnight and Tuesday afternoon. The full moon is tomorrow night, which means tides are running a bit higher right now. Sandy is also in no rush to go anywhere once she makes landfall, which means water is going to continue to pour in for a 36 hour period, making each successive high tide more dangerous than the last. Storm surge(the amount in height that the ocean will rise) is going to be about 2-5 feet for Eastern MA. Bad but not catastrophic. The biggest issue will be the duration of the storm surge. The storm surge in Long Island and further south to NYC will be in the 4-8 foot range with even some higher amounts. That DOES have the potential to be catastrophic, especially for parts of NYC. I would imagine that parts of lower Manhattan will see some of their worst flooding ever.

 Phew! That was a lot to cover. If I could convey one message to you, it would be to take Sandy seriously. Power outages are going to be the biggest issue for us and I expect them to be quite extensive. We have not seen wind speeds of this velocity in quite some time around here. I suspect that many work places and schools will be making decisions about canceling tomorrow. Most probably will. The timing will be a bit tricky, as the worst effects will be felt Monday afternoon. At the very least, it would make sense for most organizations to offer an early release tomorrow, before the heavy wind moves in.

That is all for now! I will be updating this blog later once the storm gets underway.