Our weather team has continued and expanded the First Alert for New England from 2 p.m. Thursday to 10 a.m. Friday for impactful rain, which is expected to change to snow for many overnight Thursday night into Friday morning.
The setup is a complex one: Hurricane Zeta is charging north through the Gulf of Mexico, expected to make impact at the eastern Louisiana coast Tuesday evening, likely as a Category Two hurricane, with the eye passing directly over New Orleans, delivering a storm surge, damaging wind and several inches of rain.
Zeta will weaken while continuing to move northeast across the southeast United States and off the mid-Atlantic coast by Thursday night, but will send a push of moisture north, arriving to New England Thursday morning and afternoon from the south coast to central New England, slowing the Thursday evening commute and dropping a soaking rain on the southern half of New England.
Most of northern New England will see enough cold and dry air to hold heaviest precipitation to the south from Zeta’s remnants, but the story doesn’t end here.
Intense atmospheric energy associated with a southwest and south-central U.S. snow and ice storm will cross New England immediately behind Zeta’s remnant moisture Thursday overnight into Friday morning, sending precipitation farther north through New England.
As that moisture encounters the cold air in northern New England, snow will fall, and a northerly wind will slowly bring the rain/snow line southward, eventually reaching the suburbs of Boston, Providence and Hartford by Friday morning.
Although snow amounts are not expected to be high, our First Alert Team is expecting one to three inches in the Worcester Hills, southern New Hampshire away from the coast and southwest Maine, with as much as two to four inches in the Southern Greens to the Berkshires, and a couple inches possible even in the Litchfield Hills.
By Friday midday, most of the rain and snow will be quickly breaking up, leading to a dry but blustery afternoon with high temperatures barely above 40 degrees.
Temperatures should drop below freezing overnight Friday night even in Boston, Providence and Hartford and for most of New England except Cape Cod.
Saturday will be a downright chilly Halloween beneath sunshine, with highs in the 40s and evening temperatures in the 30s.
Sunday brings some moderation, but that will likely come at the expense of sunshine, with clouds increasing and a chance of showers later in the day into the night. Another shot of chilly but dry air arrives next week, including Election Day, and rounding out the week in our exclusive First Alert 10-day forecast.