Concern continues to grow for East Coast impacts as Hurricane Sandy churns through the Caribbean, now making her move towards the Bahamas this evening. Forecast models have come into better agreement on a track with the tropical system as she moves northwest into the Bahamas, and then northeast out into the open waters of the Southwest Atlantic. Thereafter, the major changes happen which involve the US East Coast and more specifically the Northeast and Mid Atlantic. Over the past few days, we have highlighted the potential impacts from the storm system — while reminding everyone to remain objective to the situation and remember that uncertainty still exists. Much of the same applies today and as we head towards the weekend, but the potential for the storm to curve back and impact the Northeast has dramatically increased. In fact, the out to sea (no impact) solution now seems extremely unlikely. What remains to be determined is the exact track, strength, and landfall of the storm system…which will have dramatic impacts on the eventual hazards in New York, Connecticut, and New Jersey. We again answer all of your questions and give our thoughts on the event below
Keep reading for more details including three potential track scenarios and other preparedness information…
What’s the deal with this threat, why is it developing in the first place? Hurricane Sandy is currently spinning north of Cuba and is expected to shift north the next day or so. She is a strong hurricane, with maximum sustained winds over 100 mph. The pattern over the United States and Northern Atlantic ocean is completely blocked up (i.e, the pattern is very amplified, with unusually deep troughs and ridges thanks to a very low NAO and AO index). This means the steering flow (what guides the tropical storm) will bring it out of the Caribbean and then on a north, possibly northeast heading for a while. More often than not, storms in this position head out to sea. But as you can see in this diagram, there is not much room for Sandy to do that. The ridge axis building over the top of her and to her east over the Atlantic remains strong. And to the west of her, over the Central US, you can see a trough beginning to dive south and east.
How in the world can a phase bring the storm back towards the coast from the east? The atmosphere is an amazing thing. One of the most important pieces that we discussed earlier is the “Blocking” pattern, with a series of blocking high pressure systems building into the North Atlantic. In this case, most model guidance solutions are picking up on a blocking high building into Newfoundland as Sandy moves up the east coast. At the same time, an energetic disturbance moving through the Central US is sliding towards Sandy. As the two phase, Sandy cannot escape to the north and east because of the block. Instead, the disturbance over the Central US slides underneath her, phases, and a newly strengthened Sandy is forced to retrograde back towards the coast.
Okay, so Sandy is coming up the East Coast. Where is she going to head? This is the main question we’ll be dealing with over the next several days. Three main possible tracks have emerged (although we wish to remind you that there is still an outside chance the storm has a mind of its own and tracks somewhere else)
- Scenario 1: Sandy makes landfall somewhere between the Delaware/Maryland border and Long Island. This would be a worst case scenario for all of New Jersey, New York, Long Island, and Connecticut. The storm would be retrograding towards the area from the west, meaning a large storm surge would be advecting in from the southeast. In addition, this would place our area in the strongest quadrant of the storms wind field. Heavy rain, flooding, high winds, rain, beach erosion, storm surge would all be threats. Power outages would likely be widespread.
- Scenario 2: Sandy makes landfall well to our south, over the Maryland Beaches or even as far south as Wallops Island. This would still hit the area with heavy rain and southeast winds, but the core of the strongest winds in the storm system would remain south of the area..and the center of the storm would as well. High winds and storm surge would still be a concern.
- Scenario 3: Sandy makes landfall to our north over Montauk, Block Island, or Cape Cod. This scenario is the least likely of the three — and coincidentally would provide the area with the least hazards. Heavy rain and high winds would still be a threat, but the storm surge and southeast gales would hit New England instead.
What should I do to prepare now? Now is the time to start early preparations. Stay ahead of the storm. There are several preparations that we recommend to begin early. Remember that, even if the storm doesn’t hit, it is always important to be prepared ahead of time.
- Trim overgrown tree branches and bushes near your house.
- Take boats out of the water and secure docks.
- Clean leaves out of gutters and remove other debris.
- Secure loose objects and bring other objects indoors.
- Make sure your home is stocked with essentials — this includes generators, batteries, flashlights, candles.
- Know your coastal evacuation route and hurricane evacuation plan.
Finally, stay tuned for more updates, which will be giving each day going forward — and multiple times a day beginning Friday. It is very important to remember that the likelihood of the event occurring is still somewhat low. The event is still over 80 hours away — which is a lifetime for forecast models. Things can still change dramatically. So stay tuned here, and to your meteorology sources, for further updates. As soon as we get them, we’ll be passing them on.
Remember to check our Hurricane Sandy Information and Preparedness Center for live information.