East coast “bombogenesis” expected as nor’easter strengthens

Nor’easter Clips Eastern Seaboard

A classic nor’easter set up across the eastern United States will yield the first significant winter storm of the season from Florida to Maine.

Low pressure has developed along a stalled out frontal boundary off the coast of Florida. A cold high pressure system to the north is ensuring cold air is entrenched well south into the system.

Already, northern Florida and Georgia have seen snow and ice as this storm takes shape.

Rapid intensification is expected as the system tracks north just off the coast, feeding off of the large temperature gradient between the cool land and warm air over the Gulf Stream Current.

Blizzard warnings are in effect for a few coastal areas where heavy snow will combine with damaging winds to create whiteout conditions, power outages, and significant drifting snow. These blizzard warnings include the Norfolk/Virginia Beach area as well as the Delmarva Penninsula, Cape Cod, and eastern Maine.

Winter Storm Warnings are also in effect for snow and ice up and down the Eastern Seaboard with less serious Winter Weather Advisories further inland.

This storm will not be a tremendous snow maker, with top snow totals of 12-16 inches from Boston into Maine. While certainly a major storm, it will not be breaking any notable snowfall records.

The wind will be the bigger issue, especially along the coast, where beach erosion and coastal flooding are also concerns.

This storm will make its way up the coast Wednesday night through Thursday and should be departing northern New England by Friday morning.

What is Bombogenesis?

Remember a couple of years ago when the media caught hold of the term “Polar Vortex” and kicked up a massive frenzy?

The same thing seems to be happening with this storm and the term “Bombogenesis”.

Like Polar Vortex, Bombogenesis is a term that meteorologists have been using for many, many years. It sounds scary but has a very specific meaning in meteorology.

Breaking the word down, there are two parts “Bomb” and “Genesis”.

“Genesis” is a meteorological suffix we attach to words to indicate development. Thus, cyclogenesis is the development of a low pressure system.

“Bomb” brings to mind explosions.  In this case, it is a simple metaphor.

“Bombogenesis”, therefore, simply means the explosive, in other words, rapid and intense, development of a low pressure system.

Technically, “bombogenesis” occurs when the pressure of a low drops over 24 millibars in 24 hours.

Now, most weather systems that pass through on a week to week basis have pressures between 1020 millibars and 990 millibars. Those numbers represent a relatively strong high and low pressure system, respectively.

This storm is currently measured at about 1000 millibars. By Thursday evening, its pressure should be closer to 950 millibars, far exceeding the 24 millibar threshold. This is certainly an impressive display of strengthening.

Impacts in the Finger Lakes

Here in the Finger Lakes, the impacts from this coastal storm will be more indirect.

With the low pressure center tracking well off the coast of New England, no more than a few snow showers from the storm itself are expected to reach the eastern Finger Lakes, let alone areas further west.

However, there will be an arctic cold front passing through which will contribute to the snow showers Thursday.

More importantly, as the storm strengthens, so too will its winds. Behind the low Thursday evening, strong northwest winds will develop over the Finger Lakes.

Combined with the arctic front, this will usher in the coldest air we have seen yet in our recent stretch of frigid weather.

Wind Chill Watches are currently in place and will likely be changed to Wind Chill Warnings for at least parts of the region, with wind chills colder than -20 degrees expected Friday into Saturday.