High pressure overhead with clear sky, calm wind, and deep snowcover tonight – perfect radiational cooling. There will be some low temperatures well below zero, but most areas will be above, just very cold. This low launching pad for Sunday means it struggles back to the 20s as clouds increase ahead of the next storm system, which will occur Sunday night in the form of snow for all areas except for the possibility of some mixed precipitation over the outer part of Cape Cod and over the islands of Nantucket and Martha’s Vineyard. It looks like this system will drop a general 3 to 6 inches of snow across most areas, but there may be a little less than 3 inches in portions of north central MA and southern NH due to less overall precipitation, and less than 3 inches in areas where mixing occurs. There may also be a few areas that receive over 6 inches not far inland from the South Coast in south central RI and southeastern MA. Once this system exits early Monday, that day will turn out breezy, chilly, and drier with sun returning. Another cold night Monday night as high pressure moves overhead, but not as cold as tonight. Tuesday, sun will be followed by clouds as the next storm system approaches, but this one is destined to take a track northwest of New England, putting this region on the “mild” side. Remember that a deep snowcover in place will make it difficult for many areas to warm up, so freezing rain will be a possibility for some areas, along with rain where it warms sufficiently, after all areas start as snow. It is entirely possible that Boston breaks its all-time seasonal snowfall record of 107.6 inches set in 1995-1996 after the next 2 storms. After the midweek storm the confidence is a little lower late in the week as there will be some lingering moisture to the southeast and a few more disturbances in the northern jet stream, so timing and possible interaction are difficult to determine this far in advance. Will make an attempt to do this with a little more confidence on the next update.
SOUTHEASTERN NEW ENGLAND FORECAST…
TONIGHT: Clear. Lows from -15 interior valleys to +10 Cape Cod. Wind calm.
SUNDAY: Increasing clouds. Highs in the 20s. Wind light SE.
SUNDAY NIGHT: Cloudy with snow. See above for accumulations. Temperatures steady in the 20s but may rise to 30-35 Outer Cape Cod and Islands. Wind SE to S 5-15 MPH shifting to N then NE overnight.
MONDAY: Mostly cloudy early, then sunshine and passing clouds. Highs 35-40. Wind W 15-25 MPH.
TUESDAY: Sunny morning. Increasing clouds afternoon. Snow to mix at night. Lows 15-20. Highs 30-35.
WEDNESDAY: Cloudy morning with rain but possible ice inland. Mostly cloudy afternoon with rain showers. Lows 30-35. Highs 35-40 late day inland, 40s coast.
THURSDAY: Mostly cloudy. Chance of rain or mix Cape Cod. Lows 30-35. Highs 35-40.
FRIDAY: Mostly cloudy. Chance of snow showers. Lows 25-30. Highs 30-35.
SATURDAY: Partly sunny. Lows 20-25. Highs 35-40.