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.

Why the Stakes Are High with Hurricane Sandy

By now, most of you have heard the chatter surrounding Hurricane Sandy and her potential impacts in New England early next week. The wise and clever meteorologist will always preach caution when projecting confidence in a forecast period over 100 hours away, so I must preface this entry by saying that there is still a lot of changing variables and factors that can alter the outcome. That being said, special attention needs to be paid to this storm as the stakes will be higher than normal. It is quite likely that should the storm make landfall near our region, some communities will experience devastating conditions, the likes of which haven't been felt here in some 60 plus years.

I fear that some of the public might not take this storm as seriously since we just had a tropical system (Irene) last summer. Irene certainly took her toll in terms of devastation, but as far as tropical storms go, most of us got off lightly. However, this storm will be different than Irene, and different from most mid-latitude tropical storms that we sometimes see. And here is why.

1.) Strength/Duration- Typically, a tropical storm or hurricane that travels up the East Coast will quickly lose a lot of its tropical features the further North it goes. What that amounts to is a decrease in wind strength, lose of any eye wall features and a sharp cut off in the position of strong winds and heavy rainfall placement within the storm. Sandy won't be so quick to lose her tropical features. She will be aided by an abnormal feature currently setting up over the lower 48, as seen in the image below. The jet stream, upper level steering current, is about to become very tilted. Strong cold air diving south from Canada will result in a jet stream that will run from south to north by the weekend. Whats worse, this jet stream will set up just to the West of Sandy, who will be emerging from the Caribbean with a tremendous amount of energy.  Tropical systems exist outside of the jet stream and any steering currents, so this jet stream position will be two fold. It will capture Sandy and push her North but also infuse her with even more energy, allowing her to maintain and even gain strength.

2.)Abnormal blocking- In meteorology, blocking refers to a large pool of cold air way up in the atmosphere that acts as a blocking agent to normal atmospheric flow. We hear a lot about blocking in the winter, since it is a favorable pattern for nor'easter development. It just so happens that a strong block developed early this week, eliminating any escape route for Atlantic storms. It will also slow Sandy down tremendously, in a spot where tropical storms usually speed up. Remember how quickly Irene was over with? Take a look at the image above again and you might notice what looks like a "path" that is carved out right up the East Coast.  With a south to north upper level flow, an abundance of tropical moisture and strong blocking to the East, the triple threat has been set in place.

The terms like "perfect storm" and "storm of the century" have been used quite liberally in the past. But this atmospheric set up is the closest thing that meteorologists have seen to an actual perfect storm set up. As such, the negative impacts we can expect to feel will be greatly amplified, something I will address in a later post.

For now, a heightened vigilance is all that is needed. Specifics won't be reliable until we get closer to the weekend.