New England's current storm remains on track for the rest of today. As a warm nose of air aloft is driven into the region, a changeover from snow to a mix continues to advance northward. Both sleet and freezing rain have been reported within this mix. As thermal profiles continue to warm across southern and central New England, freezing rain will likely become more dominant before a switch to plain rain where the warmer air makes it to the surface.
The mix/snow line remains poised to make it all the way to the White Mountains and at least the foothills of Maine, though it will likely take much of the day to reach these northern areas. Across Vermont, thermal profiles have trended a bit colder, leading to less potential for icing with a bit more sleet and snowfall. This trend was not significant, but the northern half of the state is poised to see less freezing rain.
Below: HRRR showing potential hourly weather from late this morning through about midnight tonight:
Heading into this afternoon, the snow/mix line should make decent headway into northern New England. This warm nose is generally centered at the 850 millibar level (about 4,700 feet above sea level). At this level, temperatures are likely to rise above freezing for southern and central areas. The exact depth of this above freezing air will dictate the exact precipitation types (freezing rain, sleet, snow, rain). It'll suffice to say that much of New England will see a sloppy, slushy, icy mess through the day.
Below: Euro showing potential temperatures around 4,700 feet above sea level Sunday evening. The dark blue represents the freezing mark (32°). You can see marginal temperatures across the spine of the Green Mountains, plenty of above freezing air across southern and central New England and a rapid drop for northern New Hampshire and Maine:
There will be two main areas of focus for the potential of widespread, noticeable freezing rain rain and icing. The first will be across Western and central Massachusetts, into southern Vermont and much of southern New Hampshire. A deep layer of warm air aloft is expected here with surface temperatures struggling to rise above freezing for a while, delaying a switch to plain rain.
Below: Probability of seeing at least a tenth of an inch of ice:
The second area will be just to the west of a coastal front that sets up near the New Hampshire seacoast and Maine's coastal plain. Areas well to the north and west of this front will likely see more by way of sleet and snow while areas just east of it could switch to plain rain. Areas just to the west of it could see a narrow corridor of mostly freezing rain. This front looks to make it onshore across southeast New Hampshire and right along Maine's coast, although the exact placement is impossible to say ahead of time.
Below: Surface temperatures around mid-afternoon today. The thin red line represents the freezing mark:
A dry slot may work into much of New England in the middle of the day, creating much lighter precipitation rates for a time before another slug of moisture fills back in later. Both the dry slot and second slug of moisture will work from southwest to northeast. The dry slot likely won't be completely dry, but precipitation rates will be varied throughout the day, ebbing and flowing.
On the snowy side, a widespread 3-6 inches has been reported so far across southern and central New England. The heaviest snowfall for the northern tier of New England will be moving through from late morning through the evening hours. As a coastal low pressure system forms and strengthens, it will lock in cold air across northern New Hampshire and Maine, leading to mainly snow and sleet. An area of frontogenesis will accompany the strengthening system, allowing for snowfall rates over an inch an hour this afternoon and evening.
Below: Likelihood of at least 1 inch an hour snowfall rates early this afternoon. This band will push northward through the afternoon and evening:
The going snowfall forecast remains in good shape with additional snowfall of 6-12 inches likely across the northern third of New England as well as the spine of the Green Mountains. Northern Maine stands to see over a foot of snow by Monday morning. As the snow/mix line pushes northward, it will gradually bring an end to accumulating snowfall for central New England through the afternoon. This will be replaced by sleet and ice accumulations.
Below: Probability of at least 6 additional inches of snow through Monday morning:
The storm will wind down from southwest to northeast through tonight. Once the storm winds down, the winds will begin to crank up. With a moderately strong low-level jet and strong cold air advection occurring on Monday, widespread gusts of 40+mph will be possible. This will likely be most prevalent during the daylight hours Monday. High wind warnings have been issued for western and central Massachusetts for Monday. High wind watches and advisories remain in place for the rest of southern New England and the Green Mountains.
The low-level jet will be strongest across southern New England, leading to higher wind gust potential there than in northern New England. The main question on wind gusts will be if the maximum wind gusts can mix down to the surface. The atmosphere appears well-mixed, supporting gusts of at least 40-50mph. Whether or not full mixing is achieved remains a question. This would result in gusts of 50-60mph.
New England's next storm to watch will likely come around Thursday of next week. This could be a significant snowstorm for a portion of New England IF the track is right. The incoming cold will play a role in the track. As of now, trends have been suppressing the track outside the benchmark. As of now, the farther south and east you are in New England, the better the chance you have of seeing impactful snow from this storm.
Below: Current likelihood of impactful winter weather Thursday to Friday morning:
Comments