As of Saturday morning, Columbia, South Carolina, has recorded its earliest snowfall ever on record thanks to the anomalously cold and strong storm developing over the Eastern United States. Over the next 24 to 36 hours, this storm will move just offshore of the Eastern Seaboard, strengthen, and move through Nova Scotia, leaving New England on the northwest periphery of the storm.
Snow: In forecasts this week, I've continued to leave the door open for accumulating snow with this storm in New England, including lighter accumulations south and significant accumulations in Maine. All indications are to continue with this expectation. As rain has been developing in Eastern and Southern New England Saturday morning, near-term, high-resolution modeling continues to signal a change to snow, even into Southern New England, by later tonight.
High-resolution guidance valid at 11 PM Saturday night - radar & precipitation type forecast (blue is snow, green is rain):
Accordingly, I like the general look of the Saturday morning guidance that closley matches the overall forecast we've had running for snow on NECN - below is that guidance (12Z NAM snow guidance) - perhaps a bit overdone in the Maine heavy snow, but the idea is up to a foot in parts of Maine, and lighter amounts varying by elevation and how hard the precipitation comes down, elsewhere:
Wind: Gusty wind will increase this evening, by dinnertime, and by 8 PM onward through the overnight, multiple gusts of 45 to 50 mph will be observed with isolated gusts to 60 mph, particularly along the coast. With cooler air in place than last time (limiting mixing of momentum from aloft) and fewer leaves on the trees, damage is unlikely to be as extensive, but we certainly should be in the mindset for some wind damage reports to start rolling in this evening, and continue at times through the overnight. By Sunday morning, worst wind will be on Cape Cod, then it's widespread cold, gusty wind gusts to 45 mph through the day, which will produce isolated damage but not as active as this evening. Wind forecast maps, valid at 8 PM Saturday evening (left) and 7 AM Sunday morning (right), show gusts of 45-50 mph in darker shaded red areas:
Waves: This evening's high tide is at about 6:55 PM and will have about a foot more water than tomorrow morning just prior to 7 AM, so this evening should be the greatest impact - which still probably will only be minor coastal flooding for most. Scituate and Provincetown appear most vulnerable. That said, beach erosion from pounding surf will be an issue. Wave height forecast, valid midday Sunday, shows pounding surf will continue, even after high tide cycles mentioned: