There is a possibility that a nor’easter could develop by the middle of the week, and it may become a long-duration event for residents living in the Northeast. There is an upper-atmospheric area of low lying pressure that is going to slide southeast from the Great Lakes and spawn an area of low pressure at sea level off of the Mid-Atlantic coast on Tuesday night.
This low will remain off of the New England coast through at least Thursday. This low will only continue to intensify as it moves towards the Eastern Seaboard. There is also a strong surface high pressure system that is in place in Canada, which will then combine with the low. This will then create a tight area of pressure which will bring very strong easterly winds into portions of the Northeast. Now for New England, this will most likely be onshore winds. What does this mean? It means that it poses a risk of coastal flooding and beach erosion due to the long duration and long fetch of these winds.
This is expected to then move to the North Shore Region of Massachusetts, and will then move into Downeast Maine. The rainfall in this region will definitely not be light, and this is due to a subtropical jet stream that is making its way northward, bringing tropical moisture along with it.
Any area that is located from the northern Mid-Atlantic to New England will see the brunt of this system and will be subjected to strong winds and very heavy rains. The exact track that this storm is going to take is not known yet, but it will determine the timing and location of the heaviest rain and the strongest winds once it is figured out completely.
On Wednesday and Thursday, the northeast will see the worst of the storm. Strong winds and heavy rain will pound Maine, New Hampshire, and possibly Vermont. Over four inches is possible on both days this week. Excessive rainfall and flooding (especially near the streams and rivers) are very likely, but this storm is not all bad news.
Actually, there are parts of the Northeast that really do need the rain.
Some parts of Southern New England and the lower Hudson Valley (New York) are in a moderate drought, according to the most recent U.S Drought Monitor. Another snippet of good news is that the coldest air will stay up in Canada, so the only chance for snow during this snap of weather is Tuesday night into Wednesday morning in the Central Appalachians, where only a few snow showers are possible above 2500 feet.
With that being said, the Northeast and Mid-Atlantic need to be braced for beach erosion, high surf, and localized flooding, as this will start during the middle of the week and continue throughout Friday.
Now, what is a nor’easter exactly? The nor’easter gets its name from the strong northeastern winds that blow over coastal areas. This anomaly is most common from September and April, and it always occurs off of the Eastern Coast of the United States.
This will usually develop when the colder air from Canada meets the warm air from the Gulf of Mexico and Atlantic. This Gulf Stream will remain relatively warm during the fall and winter months, which definitely helps warm the cooler air that remains over the water. The vast difference in temperature is what fuels the storm.
A Nor’easter is not always associated with snow, although wintry conditions do occur during these anomalies. A typical nor’easter will bring locally heavy rainfall, strong winds, and coastal flooding and beach erosion off of the eastern coast of the U.S.