Ice, Rain Continues Across New England as Long-Duration Event Persists

New England's waffling frontal boundary has continued to drop southward over the past 24 hours and has settled well south of New England, around southern New Jersey. Steadier and more widespread precipitation will continue to steadily lift northward through the morning hours. The frontal boundary will also begin to slowly lift back northward as the day progresses, but will likely remain south of New England until at least late in the day.

The warm nose of air aloft will continue to work northward through New England during the daytime, deepening as it does so. This will allow for freezing rain across southern and central New England to transition to plain rain. Southern and central New England will also likely see widespread precipitation come to an end by this afternoon. Precipitation will become more scattered and showery in nature. Northern New Hampshire and much of Maine will see more numerous showers this afternoon.

Below: HRRR showing expected weather from midday Sunday through sunrise Monday:

Snow showers will gradually be replaced with a wintry mix as the afternoon and evening progresses. Temperatures will continue to gradually rise above freezing through the overnight as warm air advection continues across the region as the front lifts back northward. While much of the region will see plain rain showers by this afternoon, colder air will be stubborn to scour out across the north (as it very often is this time of year). This will allow a wintry mix to continue across northern New Hampshire and interior Maine through Monday morning.

Icing conditions will gradually improve as today goes on across areas that saw the most through Sunday morning. 0.25-0.50 inches of ice has been reported, though only scattered reports have come in as of writing. As of 10am, just under 15,000 are without power across New England with nearly 11,000 in Vermont alone. Rutland and Windsor counties have seen the highest number of outages. Vermont has seen an early peak of just over 11,000 earlier this morning. These numbers will continue to fluctuate throughout the day.

The threat for accumulating freezing rain will shift northward as Sunday progresses. Light additional ice accumulations are expected through the higher elevations of southern and central New England this afternoon. Northern New Hampshire and the Maine mountains will see the best chance for 0.10-0.25 inches of ice this afternoon and evening.

Below: Probability of at least a tenth of an inch of ice accumulations through Monday morning:

Rounds of precipitation will continue to move through New England Sunday night through Monday night. An enhanced southerly flow will commence tonight as the main area of low pressure connected to this frontal boundary lifts northeast out of the Great Lakes tonight and north of New England on Monday. This will allow the boundary to lift northward as a warm front.

The front will likely move into southern and central New England by Monday morning, allowing for a much warmer day compared to the weekend. Temperatures will likely rebound back into the upper 50s to mid 60s. Across the northern tier, it will likely take much of the day for the front to arrive. The warm front will also be weakening as it lifts into the area, so a sharp temperature contrast will be possible across New England once again.

Winter and early spring warm fronts are often over-powered among guidance. That is to say guidance often has them move through New England much faster than what actually ends up happening. With that said, there could be a time Monday afternoon where the south side of Lake Winnipesaukee is in the mid 50s and the north side is in the upper 30s to low 40s. The warmer air will spread through all of New England by Monday evening, but it will take time for the colder air to scour out across northernmost areas.

Below: GFS showing potential temperatures early Monday afternoon:

This long-duration weather event's final act will come Monday evening into Monday night as the area of low pressure to the north of New England drags its cold front across the region. This will likely set off one last round of rainfall (this will be all rain everywhere) from west to east later Monday into Monday night. With New England in the warm sector and a robust cold front approaching, scattered thunderstorms embedded within the rain will be possible.

Thunderstorms will be most likely across western New England with chances gradually diminishing moving eastward. As of now, westernmost New England has a marginal risk of severe thunderstorms. Instability will be at a minimum, so the risk of stronger storms does remain low. All of New England has at least a chance to hear a rumble of thunder, however.

Below: HRRR showing potential weather Monday night:

New England's weather will remain active after this event clears the region. There will be a brief break on Tuesday and much of Wednesday before the next storm arrives later Wednesday. This looks to be an area of low pressure rising to the north of New England. This will drag a warm front across the region, resulting in mainly rain for southern and central New England. Northern New England could see a snow to wintry mix to rain situation as the front moves northward.

Below: Probability of impactful winter weather Wednesday to Thursday morning: