DAYS 1-5 (MARCH 11-15)
The volatility of March will be on display over the next 5 days. Today, a back-door cold front is in the process of slicing across the region from northeast to southwest and will come to a stop this morning somewhere around southern RI / eastern CT, with the majority of the region spending the majority of today’s hours on the cool side with a northeast wind making it much cooler than yesterday’s late spring preview temperatures, while the cool-down is more modest in the small area that remains on the front’s warmer side. We’ll see both an increase in clouds from the west in response to an approaching trough, but as the day goes on, more ocean-formed stratus clouds will invade the sky at lower levels from northeast to southwest and a few patches of drizzle can occur in the NH Seacoast region and eastern MA from this low level maritime air flow. Tonight, the frontal boundary is going to be pushed back to the north and east in response to low pressure moving through the Great Lakes, as a stronger south to southwest air flow overtakes the region. Areas of rain showers will accompany this transition, and these will persist Thursday as that low’s cold front moves through the region from west to east during the day – creating an “upside-down” temperatures profile for the day – warmest in the morning, followed by a drop. The air incoming is cold enough that when a wave forms and moves up along the frontal boundary, we can expect to see a mix over to wet snow, with even some minor accumulation likely in portions of the region Thursday evening before clearing arrives from west to east. This chilly air mass will be in place on Friday, a day that starts with sun but ends up with clouds as the next disturbance heads our way via the Great Lakes. This low is going to pass to our north Friday night and early Saturday, so we’ll get a warm front / cold front combo. The warm front will produce a shield of snow and mixed precipitation, but the bulk of the steadiest should pass just to the north of the area, with the greatest chance to see it in northern MA and southern NH Friday late-day and evening. The cold front will swing through in the early hours of Saturday with rain and snow showers, followed by drier, but breezy weather during the day. Had enough quick change? Well, another low pressure system will approach our region from the west again during Sunday, again destined for a track to our north, dragging its warm front our way with more clouds and a chance of rain, which may start as mixed precipitation, as early as the late afternoon hours of Sunday, though the majority of that day will be precipitation-free.
TODAY: Sun gives way to clouds. Afternoon drizzle patches eastern coastal areas and a late-day rain shower possible western areas. Highs 45-52 except 53-60 western RI and eastern CT. Wind NE 5-15 MPH except SW up to 10 MPH western RI and eastern CT.
TONIGHT: Cloudy. Occasional rain showers. Patchy fog. Temperatures steady 53-60 western RI and eastern CT and rising to 53-60 elsewhere. Wind SW to S 5-15 MPH, higher gusts overnight.
THURSDAY: Cloudy. Numerous rain showers mixing with or changing to wet snow later in the day from west to east. Highs 55-62 early, then falling from west to east into the 30s by the end of the day. Wind S 10-20 MPH, higher gusts, shifting to NW from west to east.
THURSDAY NIGHT: Cloudy early including the chance of mix to wet snow with minor accumulation possible, then clearing. Lows 32-39. Wind NW 5-15 MPH.
FRIDAY: Sun followed by clouds. Late-day mix / snow possible favoring north central MA / southwestern NH. Highs 38-45. Wind variable up to 10 MPH.
FRIDAY NIGHT: Cloudy evening with snow / mix / rain most likely in southern NH and northern MA and a few rain showers to the south. Lows 31-38, coldest southern NH / northern MA. Wind variable 5-15 MPH becoming W with higher gusts overnight.
SATURDAY: Mostly cloudy morning with rain and snow showers possible, then a sun / cloud mix. Highs 43-50. Wind W to NW 10-20 MPH, higher gusts.
SATURDAY NIGHT: Partly cloudy. Lows 28-35. Wind NW 5-15 MPH, diminishing.
SUNDAY: Mostly cloudy. Evening mix potential north and west of Boston. Highs 45-52. Wind variable to SE up to 10 MPH.
DAYS 6-10 (MARCH 16-20)
Low pressure passing to our north produces a stronger southerly air flow but accompanied by abundant moisture with numerous to widespread rain showers expected for at least part of March 16, followed by a push of drier and colder air weather St. Pat’s Day on March 17 and fair, chilly weather continuing during the middle of next week before the next trough and low pressure brings unsettled weather with a precipitation chance for the day of the Vernal Equinox (10:46 a.m. EDT) March 20.
DAYS 11-15 (MARCH 21-25)
The early days of spring show signs of typical volatility with up and down temps and a couple periods of unsettled weather, the details of which will be sorted in the days ahead.