Currently: An Alberta Clipper was located over Ontario. A weak warm front generally bisected the state as of this writing. Due to the weakness of the front and no moisture available, the only noticeable effects of the front are an increase in high clouds and temperatures a few degrees warmer than yesterday.
Tonight: Skies should clear soon after sunset. This will allow for good radiational cooling, despite modest warm air advection. I'll go below guidance temps, but not as far as a great radiative night because of the warm air advection. Expect lows generally in the mid to upper 20s, except a few low 20s in the NW Hills.
Tomorrow: A cold front will move thru in the mid to late afternoon hours. Some of the higher resolution models are hinting at a round of snow showers and squalls with that frontal system. However, they seem to show it one run and lose it the next run. They are not as consistent with the threat as they were with yesterday's. Therefore, I've restricted any chances of flurries or snow showers to the NW Hills. I could be wrong, but this seems like the course of least regret right now. As for temps, guidance looks reasonable, but I trimmed a deg or two off in spots, due to temps reaching convective potential temps. Highs should generally be around 40- maybe a deg or two warmer than that in the NW Hills.
Tomorrow night/Sat: The cold air rushes in. Saturday could feel downright bitter at times, with winds gusting in excess of 40 MPH. It will be close, but wind advisories may be needed W of I 91. Guidance temps do not look terrible, but with fresh cold air advection, I went a deg below guidance. Highs should be mostly in the upper 20s.
Long Term: The two main concerns in the long term period are an overrunning snow threat on Monday and Tuesday and then a coastal low at the tail end of the fcst period.
First, for Sunday, it stays very cold with diminishing winds. Clouds could begin increasing ahead of the next sys by late in the day. Temp guidance looks reasonable, again just chopped off a deg here or there. Most highs should be somewhere around the freezing mark, except maybe upper 20s in the NW Hills.
Now for the Mon-Tue period.. First, there is the potential for overunning snows (light) as early as late Sun night/early Mon morning. However, most of the models have backed off on that. So for now, I'll just call Mon cloudy with a flurry possible during the day. By nighttime, through all day Tues, we'll carry decent chances for snow south of I 84 and a lower chance north of there. Models have come into better agreement and are also a bit further north, so if there is any adjustment, it would be north, I would think. Ptyp should generally be all snow, but some sleet could mix in over SE CT, esp if a further N track is realized. Snowfall amounts should not be huge, probably mostly under 4 inches, assuming max totals stay south. If this comes a bit further north, significant totals could be realized along the S coast, but major snowfall is not expected at this time from this system. Everyone clears out Tue night. As for temps, I went fairly close to guidance for Mon, but a few deg under guidance for Tue, expecting nearly everyone to at least be in thick cloud cover and many to be precipitating. Look for highs of 30-35 on Mon and near 30 Tue.
Wed should be a clear interlude between systems. I went close to guidance, maybe even a deg higher here or there, given some downslope component to the wind. Highs should be in the mid 30s, except near 30 in the NW hills.
Thu-Fri (I know Fri is technically outside of the fcst period, but the storm is ongoing into Fri in areas it effects): Models are in reasonably good agreement, given the lead time, that a large coastal storm will from near the Carolinas. Whether it moves NE or E from there is still up in the air. A more northward movement gets more of CT into the game. Right now, it appears to be an NYC south threat. Given that models have come north, I'll run with chance pops along the S coast, and nothing north of there as a starting point. However, there are three things to know about this sys. First, it's cold enough for all snow. Second, it's day 7-8, so significant updates in track and evolution are still possible. Finally, it's got a much higher ceiling than the early week event, because it is going to be a large and powerful coastal low. Speaking of which, I have also introduced breezy for most of CT, except the NW Hills, because even if it does not snow, this storm will likely have a large wind field and will at least produce some gusty winds across the state. As for Thu's temps, i went pretty close to guidance, except subtracting a deg across the south coast, where cloud cover will be thicker and precip chances will be higher. Expect highs mostly around 30 degrees.
Long Range: The long range features a continuation of the blocky pattern, with a continuation of the active storm track. Obviously, each storm's track and exact evolution will determine if we get precip at all, and what the type of precipitation is, but if you have cold air to work with and a stormy pattern, you usually wind up snowing at some point.
Now, let's look at our upcoming wx events in graphical form. First, I'll show you the overrunning event for early in the week, and then the potential large coastal low at the end of the week. Here is the overrunning event. This is the Canadian model, and you can see that all of CT gets measurable snow from the Canadian. Other models are further south, but have trended north.