Powerful ocean storm likely, worst impacts may stay seaward

A mid and upper level atmospheric phase is likely to force the development of a significant coastal storm, which will rapidly develop off the East Coast early next week. The storm system is expected to begin strengthening off the southeast coast of the United States, before shifting northeastward over time. As a phase between multiple disturbances occurs in the mid levels of the atmosphere, and the mid and upper level jet streaks become favorable for strengthening, the surface low pressure will deepen rapidly and the storm system will mature.

Forecast models have come into better agreement over the past few cycles in regards to the track and intensity of the system, namely the area where the system will strengthen most as a result of the occurring phase. Arguably the most notable development in terms of sensible weather in our area, is the fact that the system will “hook” eastward before phasing, taking a track from a point southeast of the Outer Banks to a position south of the 40/70 benchmark. This likely will spare our area from significant precipitation in direct relation to the coastal low, as well as more widespread wind or coastal flooding impacts.

Euro model showing a significant storm a few hundred miles off the Northeast US Coast early next week.

But despite the increasing confidence that the coastal system will head east of the area — or east enough to spare New York City the brunt of the storm system — a high degree of uncertainty still exists in regards to a few other aspects of the system. First, parts of Central and Eastern Long Island into much of Southern New England remain on the western envelope of potential major impact from the storm system. A few forecast models still show a significant snowstorm on parts of Long Island — including high winds and coastal impacts. So although the general idea is for the storm system to pass seaward, eastern areas still remain under an especially low confidence part of the forecast.

Complicating matters further is the fact that the pieces of energy responsible for the developing storm system are in sparse observation regions. In short, forecast models rely on observations for initial conditions. And if the initial conditions aren’t as fine tuned as they should be, especially in systems like this which feature incredibly delicate interactions, the result can often be model errors in multiple facets. While this day in age features much more satellite data than ever before, confidence is always higher once the pieces of energy responsible for forming the storm system are in a dense observation area or on the United States soil. And currently, the pieces of energy responsible for the storm are in Northern Canada, Northwest Canada, and the Northeast Pacific ocean.

GFS model showing the mid level energy responsible for the storm system developing early next week.

Finally, some forecast models have hinted at the development of an inverted trough near our area as the storm system develops offshore. Inverted troughs are areas of lower pressure that extend west or northwestward from the main surface low, which could be hundreds of miles away. The enhanced lift along the area of lower pressures extending well away from the center of low pressure can cause precipitation development — in our case, it could mean snow developing even though the system is well off the coast. Unfortunately for us, these inverted troughs are extremely difficult to forecast — and model guidance can never seem to pinpoint exactly where they will set up.

Over time, these details will become much more apparent and we are beginning to approach that time period. The storm system develops rather quickly, so these pieces of energy will begin to come into the more dense data areas by Sunday night — adding confidence to the forecast. That being said, even now, given the consistent model guidance consensus — our confidence is slowly rising in the fact that our area will escape the greatest impacts from the storm system early next week, and that winter weather impacts will be higher east of the city if they do materialize.

We have our eyes peeled to the storm system and new data which we will continue to analyze and interpret. We encourage you to stay up to date with our social network accounts and obviously the blog for the latest updates, which will become more numerous as the storm approaches.