Boston, North Shore and Metro West: The month of October is closing out in a matter of days and at this point in the month the Boston area is running about 2 degrees above normal for the month. Another mild day is on tap for Wednesday as a warm front lifts north of the area opening the door for milder air to move northward on a south to southwest flow. Mild air will stay in place overnight and through Wednesday ahead of an approaching cold front to our west. After tomorrow temperatures begin to cool down dramatically and by the time November dawns on Saturday we are going to be feeling like it is late November or even early December as it becomes really chilly in these parts.
Wednesday brings a lot of cloudiness and widespread morning fog to the area with a chance of a passing shower or two in the afternoon and evening. The approaching cold front moves across eastern Massachusetts later in the day then offshore Wednesday evening. After a day in which high temperatures will likely reach the upper 60s and low 70s, some 10 to 15 degrees above normal, the mercury will take a good tumble Wednesday night into the 40s as much cooler air rushes in on northwest winds behind the cold front.
High pressure marches eastward on Thursday allowing for a mostly to partly sunny day, but with much cooler temperatures. Highs in the mid to upper 50s are actually more in line with average highs for late October. Under a clear sky and calm winds expect a chilly night as temperatures fall back into the mid 30s to low 40s, coolest across the interior sections.
Halloween day remains dry and cool, although all eyes will be watching for a storm to develop over the open waters south of New England. Sunshine gives way to an increase in clouds by late in the day, highs in the 50s.
Halloween night becomes mostly overcast with a chance of a shower later at night. It should stay dry for the trick or treat festivities during the evening. With temperatures falling back into the upper 40s during the evening it is going to be a cool evening with readings bottoming out in the upper 30s to low 40s.
Everyone is talking about the possibility of snow later in the weekend, primarily Saturday night, possibly Sunday as well. A storm is going to slide down from western Canada and move southeastward toward the Great Lakes over the next few days. There is a wedge of very cold air that is riding down from northern Canada. Energy is expected to transfer to the coast and trigger a storm to develop over the waters to our south which will then move southeast of Cape Cod Saturday night. The location of storm development and the eventual track will be critical in determining the extent of rain on Saturday. With much colder air slipping into the area it is not out of the question that snow could mix in Saturday night and possibly on Sunday as the low moves to our east during Sunday. The event is over three days away and as usual there is a lot of fine tuning that needs to be done over that span to get a better handle on what will most likely happen.
What is certain though are going to be the much below average temperatures as daytime highs remain in the 40s Saturday, then struggle into the low 40s on Sunday. Lows during the overnight in the 30s. Welcome November and Winter on the same day. But, it will not last long as there are signs of another mild spell next week.