Arctic Blast On The Way
The temperature reached 26 degrees at 1:34pm in Boston today. Despite highs being about 10 degrees below the average for this date, it actually was "balmy" compared to what we'll be feeling late tomorrow through Monday night. Arctic air has spread out across just about all of Canada and some of it is pressing just across the border into the United States. Once an upper air trough passes tomorrow, the gates are wide open for this harsh cold air to flow into the Northeast. A developing storm off the North Carolina coast this evening will intensify into a strong gale center way offshore and actually assist in pulling the chill in from Canada. As the arctic cold front settles southward across the area tomorrow, most of the attendant clouds and any widely scattered flurries will occur in the morning. The air appears to be too dry to produce any widespread activity. There is a slight risk that more of a northerly wind could create some beefier ocean-effect snow showers for mainly outer Cape Cod in the afternoon and evening as the much colder air arrives. After falling to the middle single numbers to lower teens tonight, temperatures tomorrow should rise up to the upper teens across Worcester County to near or slightly over 20 in the Boston area to the lower to middle 20s over southeastern MA by midday before falling back a few to several degrees as the afternoon progresses. The National Weather Service has issued a WIND CHILL WATCH for northern Middlesex County into much of Worcester County west and north from late tomorrow night through Monday morning. This means that there is a potential for wind chills to fall to -25 or colder for at least 3 hours. A wind of only 10 mph when it is 10 to 15 degrees below zero would creat the dangerous windchill temperatures of at least -25. Check out these safety rules for extremely cold weather. Outside this watch area, I am predicting lows of 5 to 10 below zero in the closer northern and western suburbs with -2 for Boston. This would match the last subzero reading in Boston on January 22, 2005. Interestingly, based upon statistics, the lowest temperatures of the year occur in the period of January 20-23. I am not expecting any record low temperatures in Boston in the next couple days. The city's record for Monday, January 24th, is -13 set in 1882. However, there could be a few near or broken records such as at Worcester where the record for Monday is -14 set in 1948. I anticipate -10 or -11 at the Worcester Airport that morning. With an arctic cold high pressure system sprawling out over the region on Monday, it probably will not warm up above 10 degrees farther north and west of Boston to near 12-14 in Boston to 14-18 over southeastern MA! Brrrrrrrrr! It will sting but, fortunately, there will only be a breeze mostly under 10 mph. Boston's lowest temperature last year was 6 degrees set on January 30th.
Looking ahead, the high pressure system weakens and shifts offshore Monday night into Tuesday. As this is happening, a weak perturbation in the northern stream will introduce much cloudiness with a risk of spotty light snow or flurries on Tuesday as a weak boundary grows into New England. Meantime, in the southern stream, a short wave will be digging southeastward from the Plains States. In response to that, a wave of low pressure will form near Louisiana and tap Gulf of Mexico moisture. It will begin shifting northeastward toward the Carolinas later Tuesday. There has been much conjecture over the last few days about the potential of this system. I must tell you that it remains highly speculative this evening and absolutely nobody can be confident about the future course of this system at this time. Earlier runs in the past couple days have depicted another major storm of snow, ice, rain and wind for us but, seemingly, the latest indications point to directing the storm farther offshore thanks to upstream kicking and unphasing jetstreams. Consequently, our region may only be impacted by the northwestern flank of this deepening ocean storm. That is just my latest thinking but there remains a degree of uncertainty with this so I submit that we must wait until Monday's guidance offers a hopefully more defining portrait of how this is all going to shake out.
Joe Joyce delivers his latest AccuWeather Forecast in the morning and I shall return later in the day.
Enjoy the rest of the weekend.
