Rain, Mixing Continues for New England Through Monday Before Cool-Down

Thermal profiles today will continue to allow for snow or a wintry mix across Vermont and northern New Hampshire through this morning and into the early afternoon. This will come as these areas will remain on the north side of a warm front lifting toward New England today. This comes as a system in the Ohio Valley continues to lift northeast within a deep trough over the eastern United States.

This setup will allow for warm air advection to occur through the day. This will allow for rising temperatures after a cold morning for southern and central New England. The northern tier will likely remain north of the warm front all day and stay generally chillier through the entire day. As always with this setup, it's tough to say just how far north the warm front will push by Sunday afternoon, but it won't make it too deep into northern New England. Areas south of this front will likely push well into the 40s and possibly all the way to the mid 50s while northern areas are apt to stay in the 30s and low 40s.

Below: HRRR showing potential temperatures around mid-afternoon today:

Showers will likely increase from south to north as the afternoon and evening go on. This will continue into the first part of Sunday night. By midnight tonight, a majority of the precipitation will likely have pushed into Maine, with continued spotty showers elsewhere. Showers will tend to be on the lighter side throughout this event, with a widespread quarter to half inch likely through Sunday night.

Mixed precipitation across the north will generally change to plain rain through today and into tonight as warm air advection continues. The only area really expected to remain wintry all night is northernmost Maine. Areas outside of the mountains should see all rain with this one, with some mixing for the mountains and northern valleys. With warmer air aloft and colder air at the surface across northernmost New England, a period of freezing rain will be possible. This would be most likely across the valleys of Vermont and northernmost Maine.

Below: HRRR showing potential weather early this evening (1st image) and later tonight (2nd image):

A winter weather advisory has been issued for northern Maine (the first of the season for New England). This is in effect from this evening through Monday morning. Precipitation here is expected to arrive late this afternoon and continue through about sunrise Monday. 1-3 inches of snow is possible along with a trace of ice as warm air working in aloft helps to change the snow over to freezing rain.

This changeover would occur from the Maine Mountains northward through the night. Evaporative cooling processes may allow the precipitation type to remain snow for a longer period of time across the Crown of Maine, which is why a few inches may be possible before any switchover.

As the center of the low pressure system lifts north and west of New England Sunday night into Monday, a secondary area of low pressure will form around coastal New England. This will allow for another round of showers to develop for Monday, along with some gusty winds. Overall, this shouldn't bring too much by way of impacts as the secondary low pressure system looks to remain on the weaker side.

How much wintry precipitation falls in western New England will be a race between the colder air moving in and the end of precipitation. Overall, not too much is expected from this system, with another widespread tenth of an inch to quarter of an inch of rainfall across New England on Monday.

Below: HRRR showing potential weather Monday afternoon:

What this system will do is pivot the warm front up into Maine during the day Monday. This will come as the system's cold front moves west to east across the region. This will set up a west to east temperature divide across the region. Monday will start off mild for most before temperatures gradually fall through the afternoon and evening from west to east as the cold front moves through. The only area likely to warm all day will be eastern Maine, where it could briefly surge into the mid 50s just before the cold front as the front naturally reaches them last.

Below: HRRR showing hourly temperatures from sunrise Monday through Monday evening:

This cold front will be strong and temperatures will fall sharply behind it as it pushes across New England (and across the entire east coast all the day to Florida) on Monday. This will bring a shot of Arctic air through the east. This blast of air is more reminiscent of a mid-winter Arctic blast than an early-season cold front. Tuesday will likely see temperatures bottom out, with highs in the 30s north to mid 40s south. This will be cold for the time of year, but it will be the south that will see the brunt of this cold snap (relative to their seasonal averages).

A ridge-in-the-west-trough-in-the-east pattern will set up this week, with chilly temperatures and continued unsettled weather on tap for New England. While Tuesday will be the coldest day, much of next week will remain on the chilly side. Broad cyclonic flow will be over New England. This will create plenty of clouds and the potential for quick, pop-up showers and flurries Tuesday through Thursday. Precipitation will be most likely within the mountains. It's possible a subtle shortwave enters the area later Wednesday to Thursday, allowing precipitation to become a bit more widespread across New England, but we'll see.

Below: 500mb height anomaly on Wednesday, showing troughing remaining over New England: