Dramatic Changes Ahead
As of 7pm this evening, Boston's temperature has been below 32 degrees for 165 consecutive hours! The total will reach 182 or 183 hours then the city's temperature will finally rise above freezing by a degree or two. That will happen early tomorrow afternoon when a shield of snow will be arriving in eastern MA from the west. Undoubtedly, the snowfall is destined to impact the homebound commute. The pavements are plenty cold so it will not take much snow to make traveling tricky. Road treatment will help but I predict that a mere inch or two by 6pm will slow the flow so just take it easy and plan on extra time to get to your destination tomorrow afternoon and evening.
As the sky remains mainly clear and brightly moonlit for at least the first half of this night coupled with subsiding wind, the temperature will decline steadily or even quickly as radiational cooling flourishes. It will fall into the teens then stop somewhere in the upper single numbers in places after midnight. By daybreak, the high thin cloudiness will be appearing and may result in a very colorful sunrise in spots. Morning sunshine will become filtered and dim rather swiftly as the shield of snow advances from NY and PA. It will press across western MA by noon then into Boston in the 2-3pm hour. It is created by an approaching frontal boundary of warmer air. A weak wave of low pressure may form along this axis and warmer air arriving aloft suggests a transition to sleet and freezing rain tomorrow evening before the precipitation tapers off after midnight. It may turn warm enough at the surface for a complete turn to plain rain across southern CT, RI and southeastern MA. As the wave tracks east southeastward and off the coast by early Tuesday morning, the frontal boundary will linger across southern New England. Under a mostly cloudy sky with light winds, the temperatures will slowly creep up to the middle to upper 30s Tuesday afternoon with 40-45 in places south of the MA Pike.
Going forward, as an upper level trough amplifies sharply in the central portion of the country, a resultant surge of warm air will charge into the Northeast including New England. This surge will push the stalled frontal boundary northward and temperatures should rocket on Wednesday with highs easily reaching well into the 50s. Some lower 60s are possible as the air turns more humid via gusty south-southwesterly winds. An outbreak of sunshine would send temperatures to record-breaking levels in the upper 60s but I think that there will be considerable low-level moisture in place that will be tough to scour out as much mid and high level cloudiness arrives from an approaching strong cold front. Consequently, the 1914 record high of 63 for January 30 may be challenged but it is unlikely to be broken. This frontal boundary may trigger some strong to severe thunderstorms along the eastern seaboard Wednesday into Wednesday night. Thunder cannot be ruled out in this area as a ribbon of heavier rain and howling winds pass through later in the evening to just after midnight. With the passage of the cold front, the air will dry out rapidly and the temperatures will fall from the 50s that evening down to near 40 by dawn Thursday. There will be gusty westerly winds on Thursday with a mix of sunshine and fast-moving clouds with highs of 40-45.
Looking ahead, colder air will be draining in Thursday night so it's right back to bad habits on Friday with varying amounts of clouds and sunshine with a brisk cold wind and highs in the upper 20s. The next weather maker will arrive late Saturday and depart by midday Sunday. It will be a clipper system dropping across the Great Lakes for some moisture then releasing it in the form of a period of snow or snow showers. There could be some accumulation early Sunday but this feature looks quite progressive so there should not be a large amount of snow released. As the storm intensifies over the Maritimes, it will strengthen the wind and pull in more very chilly air from Canada for Sunday afternoon and Monday.
Melissa Mack delivers her latest WBZ AccuWeather Forecast in the morning and Todd Gutner follows later in the day.
Make it a great week!
