Last night's burst of snow in northern New England was generated by a wayward polar vortex positioned over Ontario, Canada, where record cold has been in place all week. At the same time, we had baseball-sized hail in Oklahoma and Texas.
Those two weather systems are going to merge east of Maine tomorrow. Most of New England is getting just the initial phase of this merger with a batch of rain and snow tonight.
The new storm center is poised to intensify rapidly as 'Bombogenesis,' moving northeast from the Ohio Valley and crossing through New England.
The storm center is along a cold front that represents the leading edge of a shot of cold weekend air, and where that new air arrives first, the rain will change to snow in northern and western New England, even into the hilly terrain of northern and western Worcester County.
Most of the rain and snow kicks out by dawn Saturday except for northern New Hampshire into Maine, where snow still falls Saturday morning, while a blustery blend of sun and clouds takes over elsewhere in New England with wind gusts to 45 mph late in the day for an isolated tree or limb down, a wind chill factor that never rises out of the 30s, actual highs in the 40s and a few sprinkles and flurries cropping up from time to time.
On the southern edge of the snow, only a coating on the grass is expected overnight with wet roads. But the farther into northern New England one is, the greater the impact from the snow with a heavy dependence on elevation. We will see one to three inches of snow in northern and western New England with deep valleys seeing less, high terrain seeing more and roads impacted only where two inches or more falls.
Saturday night reinforces the old school New England thought of waiting to plant until later in May. We'll drop into the 20s and 30s and the wind will continue to whip.
The wind continues to gust as high as 35 to 40 mph on Sunday, but the chill relaxes as highs climb to 55-60 degrees by Mother's Day afternoon under a fair sky.
An approaching disturbance Monday may deliver some scattered showers, but it should leave a quick shot of cool air in its wake Tuesday and Tuesday night.
Behind that is another batch of cool to record cold air with a hard freeze possible Wednesday morning.
After that, we have a warming trend for the end of next week in our exclusive First Alert 10-day forecast, though the chance of showers is likely to rise with that warmer air.