11:30 PM
Spring has begun, at least according to the calendar. At 7:21 PM, the Vernal Equinox occurred, marking the beginning of spring. But we all know that this event does not always mean we have seen the last of the cold & snow for the winter weather season. And this will certainly be true this year. Our old friend, the negative NAO (North Atlantic Oscillation) is coming back, putting us back into a colder than normal pattern for the balance of March and the early part of April. Along with this will be several threats of late-season snow. The first such threat is only hours away, as a low pressure system racing eastward through the Great Lakes moves into the region on Monday. The air will be cold enough during the first few hours of precipitation so that some snow occurs. Some minor accumulations are expected, especially inland, over higher elevations, and on unpaved surfaces. Main roads closer to Boston are not expected to suffer major impact from this system, which will end as rain Monday evening as milder air will have moved in above us.
A narrow area of high pressure will provide drier, chilly weather for Tuesday. But already we’ll be turning our attention to the next threat of precipitation, which exists from late Wednesday through Thursday. The details are sketchy on how this system will set up, as there is conflicting computer model information. My best guess on this system right now is that we will get through Wednesday dry, but sometime Wednesday night or Thursday we will see a shot of mixed precipitation and snow, the extent of which will be determined by the positioning of an inverted trough of low pressure setting up over southern New England. These types of systems can become the focus for significant precipitation, without a major storm system, and they are very tricky to forecast. So we will just have to follow this to see how things set up as we get to the middle of the week.
Another episode of drier, chilly weather is expected at the end of the week, into the weekend. But a peek into the following week shows that a chilly and possibly storm pattern may be with us…
Detailed Boston Area Forecast for the next seven days…
TONIGHT: Cloudy. Low in the middle 20s. Wind south under 10 mph.
MONDAY: Overcast. Precipitation developing during the morning and continuing through the afternoon, falling as a mix of rain/snow when it’s lighter and snow when it’s heavier until 3 or 4 PM when it will become all rain. Snow accumulation of less than 1 inch near the coast and south of Boston, 1 to 2 inches mainly on unpaved surfaces away from the coast, and 2 to 4 inches over the higher elevations of inland Middlesex County and Worcester County as well as nearby southern NH. High in the middle to upper 30s. Wind southeast to south up to 10 mph.
MONDAY NIGHT: Cloudy with light rain tapering off during the evening. Clearing overnight. Temperature steady in the middle 30s. Wind W 5 to 15 mph.
TUESDAY: Mostly sunny. High in the middle 40s. Wind north 10 to 20 mph gusting to 25 mph.
TUESDAY NIGHT: Mostly clear. Low in the middle 20s. Wind north diminishing to under 10 mph.
WEDNESDAY: Increasing clouds. High in the lower 40s. Wind light variable.
THURSDAY: Chance of snow. High in the middle 30s.
FRIDAY: Clearing. High in the upper 30s.
SATURDAY: Mostly sunny. High in the lower 40s.
SUNDAY: Partly cloudy. High in the middle 40s.