If you want to get done with some last-minute late fall activities, like stringing up Christmas lights, this may be the week to do it!
Currently: Not much going on across the Eastern United States. High pressure has shifted East of Nantucket. With the high to the east of the region, most areas will see above normal temperatures, but spring-like sea breezes will be possible along the south coast.
Tonight: Uncertainty as to how much cloud cover we'll have. However, there should be at least some cloud cover. This, combined with weak warm air advection, leads me to go a couple degrees warmer than most guidance for low temperatures tonight, so generally 40-45, except upper 30s in the NW Hills.
Tomorrow: Plenty of sun. Not a lot going on. Temperatures above normal. Guidance is in good agreement and generally accepted. Highs should be 55 to 60.
Tomorrow Night/Thu: A strong cold front moves through tomorrow night and temperatures turn much colder. Clouds increase ahead of the next system on Thursday. Look for lows from the low 20s to low 30s and highs 40 to 45.
Long Term: The weekend and beyond: The first system of note is Friday. This system was initially modeled to be a large Great Lakes Cutter. However, the modeling has since significantly change (as the developing blockiness up north gets modeled better). Now most models agree that this is just a cold frontal passage. However, some precipitation, mainly centered on Friday morning, is still likely with this system. Temperatures Friday morning should generally be in the upper 30s, and most of the upper level profile is above freezing, so this should be a mainly (light) rain event. However, some sleet pellets could mix in at the end in the north. Since precipitation amounts will be light and temperatures above freezing, there is no concern for any frozen precipitation accumulation. As skies clear later Friday, it should turn into a decent day, with highs of 45-50 and a few lower 50s possible in the I 91 corridor.
Saturday should be a lull in between systems and a relatively nice, crisp fall day, with high temperatures generally the same as those of Friday. Then on Sunday, the next system to watch will be something of an inverted trough. These systems are notoriously tough to forecast until the last minute. There is a weak coastal low, which could amplify things as well, but right now most modeling keeps the two systems separate. However, it would not take much for these to move closer to each other with time. The latest GFS has trended significantly colder in the upper levels with this system. There hasn't been much change with surface temperatures, verbatim. However, it is important to note that if the upper levels are significantly colder and precipitation is heavier, surface temperatures would be much cooler and this would not be modeled correctly. So how does a meteorologist handle all this at this juncture? For now, I'll go for a chance of snow showers (at least) around midday, and I'll cautiously go a few degrees cooler than guidance, keeping high temperatures under 45 degrees. Although this forecast could be subject to significant changes.
The beginning of the next work week should be fairly tranquil and a bit warmer. The strong cold front that will be the nail in the coffin for any warmth should pass through on Wednesday afternoon, with a line of brief heavy showers, possibly ending as snow in the north, IF precipitation holds on into the cold air. As for temperatures on Monday and Tuesday, I'll go with 45-50 for Monday and low 50s on Tuesday as we warm up ahead of the cold front.
The long range looks cold. Nearly all modeling is in agreement that Canada largely becomes blocked, which would displace the cold air into the continental United States. As far as any wintry threats, as always, they would ultimately depend on the trough orientation when an individual wave shows up, but let's get cold first and go from there!
Now, let's take a look at some graphical products, to help illustrate how our weather pattern will be evolving over the next week and beyond. First on deck is Friday morning's cold frontal passage. Here is a model depiction of that. Notice on this map, valid in the predawn hours on Friday, precipitation is just starting to move into the western portions of the state.