Tonight: As the coastal low pulls away and with the loss of daytime heating, showers and thunderstorms will dissipate quickly after sunset. One more coolish night is in store for much of the state before the weather turns much warmer. Lows tonight should be in the 50s.
Tomorrow... sunny and much warmer. It will feel like late May or June. High temperatures should be in the 80-85 degree range.
Tomorrow night into Thursday: A continuation of a similar pattern. However, the winds will be lighter on Thursday, which could promote sea breeze development along the immediate south coast. At the moment, models are not in good agreement regarding this, so temperatures would be highly dependent on that along the Sound. A fair compromise at this point would be to go just a couple degrees cooler than Wednesday for those areas, with similar temperatures elsewhere. Low temperatures tomorrow night should be within a few degrees of 60, with highs on Thursday again in the 80-85 degree range, but with the potential to be a few degrees cooler right along the Sound. A back door cold front will approach late in the day Thursday. At this time, deep layer moisture appears to be lacking, so the chance for thunderstorms with the front appears to be very low at best, but this could change.
Longer Term: On Friday, a backdoor cold front will be south of the state, bringing cooler air with it. With more clouds than sun, but no rain expected, lows should be again a few degrees of 60, with high temperatures in the 70s.
On Saturday, the backdoor cold front will return north as a warm front. Right now, it looks like the timing of this feature will be too late to cause a significant change in temperatures during the day, but rather produce a more muggy night. This time around, there will be more moisture and instability present, so there is a pretty good chance of showers and thunderstorms, beginning Saturday evening and lasting until Sunday morning. High temperatures on Saturday should be a couple degrees warmer than those of Friday- in the upper 70s.
On Sunday, any lingering showers and thunderstorms clear out in the morning. This backdoor front probably drapes itself somewhere across Long Island. This will leave Connecticut in the cooler sector. Although most of the day Sunday will be rain-free, it will be generally cloudy, and high temperatures should only be in the low 70s.
For Memorial Day, a strong onshore flow will persist throughout the day, keeping most areas in the upper 60s. A few interior places could touch 70, though, away from the water. There are some hints of the next system bringing rain to the state, but it looks like that will wait until very late at night at the earliest, so at least we can keep precipitation out of the forecast.
Finally, for Tuesday, the next system will approach the area and could even spawn a coastal low. This will keep most of the day gray and rainy, if it occurs, with high temperatures in the 70-75 degree range.
The long range pattern in a word looks stormy. Various frontal systems will be very close to the state through much of this period, keeping the area in the crosshairs for showers and thunderstorms. There could be a couple warm days, like what we're going to see tomorrow and Thursday, but there don't look to be a any long-lived periods of hot weather any time soon.
Now, here is a graphical look at some of the features in the upcoming pattern. First, let's look at the GFS' forecasted high temperatures for tomorrow.
Finally, let's look at a graphical presentation of high temperatures for Memorial Day. You can see Connecticut is clearly on the cold side of the boundary, with the hot temperatures restricted to the Southeastern states.