NAM 3k model showing the locations of the Friday and Saturday/Sunday lows. Image courtesy of Tropical Tidbits.

Throughout this entire overnight process, the low is gathering warm, moist air from the Gulf of Mexico to fuel itself before its inevitable march Eastward. And with a number of blocking high pressures to the East and North, the low will continue to remain within striking distance of the Gulf for a significant period. The entire time, the system will be taking in and distributing moisture, building what will likely become a massive moisture plume by the end of the day on Saturday. Below is a picture from the ECMWF model runs of the low pressure on Saturday morning and Saturday evening for comparison.

You may notice that on the evening ECMWF run, the moisture plume has extended to reach the majority of New England. It’s truly impressive that while the center of the system remains in the Mid Atlantic, it has gathered and dispersed enough moisture that it is forecasted to precipitate as far away as Maine at the same time. And at this point, the low is only beginning to reach its point of maturity.

Overnight Saturday and into Sunday, the low will continue to propagate East, dumping large amounts of rain and snow as it moves. After crossing over the Appalachians and reaching the waters of the East coast, the low will ingest more available moisture and reach its peak intensity. And after sunrise on Sunday morning, the center of the low will crash into New England proper, producing some impressive rain and snowfall totals. By the end of the day on Sunday, 1.5 to 2.5 inches of a wintery mix of precipitation could fall across the Southern portions of New England, an approximately 16 inches of snow across the Northern portion where temperatures will likely remain at or below freezing. At the summit, we are even expecting snowfall totals near 20 inches!

 

 

ECMWF model showing rain and snowfall totals for Sunday Morning. Image courtesy of Tropical Tidbits. 

This low will be a classic Miller Type B Nor’easter. Once these lows cross over the Appalachians and intensify, they are well known for producing a considerable amount of precipitation before they depart offshore. Additionally, with their tight pressure and temperature gradients, wind speeds will be on the rise as well. I’d expect no more than 15 to 20 mph near surface levels, particularly on Sunday night in Monday as the storm moves off. But on the summit, we could see winds ramping up into the 100 mph range as the low centers in.

Additionally, if we look just outside the forecast window in MLK Day, temperatures are likely to plummet following the low’s associated cold front. Subzero temperatures are not out of the question for most of New England, including New Hampshire, Vermont, Massachusetts and Connecticut. So it certainly has the potential to be a frigid, blustery holiday.

It certainly is a lot to take in. But the takeaway here is that the models agree with the strong potential for a Nor’easter to blast the coast by the end of this weekend. States further South can likely expect heavy amounts of rain and wintery mixes in precipitation, while the Northern states are in for a considerable amount of snow. And in this winter storm’s wake, a brief period of elevated winds and frigid temperatures would be expected; even more so here on the summit of Mount Washington.

Model agreement is high and consistent, NWS offices are putting out Winter Storm Advisories, Watches and Warnings, and with each passing day the atmospheric structure proves to be more and more conducive for a big storm. We will continue to monitor the storm’s progress over the course of the weekend, and will certainly be outside Sunday morning for our Facebook Live update to check it out! It looks like it’s going to be quite exciting, so make sure to stayed tuned in the coming days as we track this impending Nor’easter! And be sure to check out our forecast products on our website for more information!