Brrrr! A Very Cold Week Ahead!
On this Saturday, many areas were sunny all day while a few places were mostly cloudy namely most communities in Essex County and in the Connecticut River Valley. Just after sunset, it cleared over northeastern Massachusetts while patches of clouds wandered into central and southeastern portions of the state. Today's highs of 40-43 except upper 30s in the Worcester Hills will likely not be reached over the next week. Temperatures were about 3 degrees below the average today and by midweek, they will be about 12-15 degrees below the average. There is no doubt about it. The cold is in control.
An interesting upper air pattern exists featuring a strong blocking upper air high pressure system in the North Atlantic(-NAO) with an upper air low pressure center over New England. In this LaNina, the jetstream charges southeastward across western Canada to the upper Mississippi Valley then out over the Southeastern States into the negatively tilted mean trough. Disturbances in the upper level wind field ride through this stream and intensify upon entering the trough offshore. One such perturbation will create a deepening surface storm over the ocean well east of North Carolina tomorrow. It will follow through the field of flow northwestward into Nova Scotia, New Brunswick and northern Maine on Monday then weaken near the St. Lawrence River Valley on Tuesday. This track protects us from precipitation but the colder air is released from central Canada and makes its way into our region. The coldest air arrives Wednesday following the passage of an arctic cold front early in the day which may trigger a few passing snow showers or possibly a squall. Prior to that, expect sunshine and patches of clouds both tomorrow and Monday with highs in the upper 30s and middle 30s respectively. It will be blustery on Monday and still breezy on Tuesday and Wednesday with lighter wind on Thursday when a ridge of high pressure moves in and the tempertature fails to rise up to 30 degrees!
At the end of the week, the forecast becomes more uncertain. It appears that a weak wave of low pressure will shift across the Great Lakes into southern Ontario. It may force a strip of warm advection light snow or flurries into the area next Friday morning. After that, the southern stream contributes a short wave disturbance which will trigger a storm feeding on some moisture from the Gulf of Mexico. Most signs indicate it will not have the support to blossom into a major storm but some rain over southeastern sections with snow north and west of Boston and a mix near the city is possible on Saturday. There could be a more energetic close call ocean storm on the 13th or 14th. Obviously, next weekend and beyond is too far out to confidently predict at this time. It will be interesting to follow subsequent forecast cycles over the next several days.
Joe Joyce delivers his latest AccuWeather Forecast tomorrow morning and I shall return later in the day. Enjoy the rest of the weekend.