Currently: A complex storm system was affecting the region. The old "parent" low pressure system was located over the Great Lakes. A trough with weak waves of low pressure attached to it was located over the Appalachian Mtns of VA and TN. Meanwhile, a secondary low was developing over the Jersey shore. With most of the low pressure systems west of our area and not much of a cold air source, precipitation has been almost exclusively rain across the state.
Tonight: Steady precipitation will generally wind down, but with all these low pressure systems, it will take some time. Expect precipitation to wind down in the west around or just after midnight, but not until dawn in the far eastern sections. As for temperatures, the GFS has initialized 5 to 8 degrees too warm, so most of that guidance is discounted. Even having said that, the NAM looks a degree or two too cold. So I'll go with lows closer to, but not all the way down, to the NAM guidance. Therefore, expect lows in the upper 20s to mid 30s. Fortunately, the "colder" areas will likely see precipitation shut off before temperatures fall below freezing, while the "warmer" areas will see rain continue to fall. The only exception could be NE CT. Temperatures aloft are much too warm for anything other than rain. So this area may need to be watched for a period of freezing rain tonight.
Tomorrow: I will do the same with temperatures tomorrow as I did today. The GFS just doesn't seem to realize we have cold air advection occurring. In addition, convective temperatures are low, so even if we did surge upwards in temperatures, clouds would quickly develop and put a lid on the temperature rise. So even though NAM temperature guidance generally exhibits a cold bias, I'll go much closer to it than the GFS. Expect highs tomorrow in the 40 to 45 degree range. Some spots in the NW Hills could stay in the upper 30s. As for precipitation, I'll keep it out of the forecast, because I don't think anyone measures. But with a ULL spinning overhead, I can't rule out a flurry late in the day. The best chances for that would be west of I 91.
Tomorrow Night/Wed: With thicknesses as low as they are progged, my feeling is that temperature guidance is way too warm. In fact, even the NAM may be a bit too warm, so I'll go under everything. Gridded data also supports my reasoning. (Even if the air mass origin is not that cold, it is still January). So expect high temperatures generally in the upper 30s, maybe a few low 40s in the I 91 corridor. Otherwise, a sunny, normal winter's day.
Long Term (Thursday through the weekend): For Thursday, with the wind flow turning SW, temps will moderate. Temperature guidance is not as bad by then, but I still may need to shave off a degree or two with lingering LL cold air. So expect highs in the 40 to 45 degree range.
The next storm system affects the area on Friday. There are a lot of questions still lingering with this system, mainly regarding speed and total precipitation. I will go with the GFS on speed, which is faster than most of the guidance. But since the model has been consistent with this and we are not in a blocky pattern, I see no reason to believe that the system will not scoot right along. I will go wetter than the GFS, however, since it has trended wetter and generally runs too dry at that range. Overrunning precipitation overspreads the state very late Thursday night and precipitation could linger until very late Friday night. However, some of the new guidance is indicating that there could very well be a break later Friday afternoon into early evening hours, so it may not rain the whole time. Despite what the calendar says, there is no question with precipitation type with this system. Thermal profiles, even at the surface, support all rain for the duration for the entire state. I will go several degrees colder than the GFS temperature guidance, since it tends to like to blast warm fronts through the area when they really do not make it this time of year. Additionally, even if we do get a break, we likely will not see any sun, as most of the state will not see the break in precipitation until after sunset. Therefore, there shouldn't be any solar insolation to boost temperatures. So expect highs generally in the low 40s, although I could be a degree or two too cool in a few locations. It's best not to get too cute this far out.
For Saturday, I'll go a few degrees under temperature guidance because I think we're more cloudy than the GFS indicates. It wants to clear us out too fast. However, the air mass is quite warm. So even after lowering guidance temperatures, we're still looking at highs around 50 degrees throughout the state.
With a strong cold frontal passage Saturday night, albeit a dry frontal passage, Sunday's temperatures should be much cooler. As is typical this far out, GFS temperature guidance does not seem to recognize there is cold air advection occurring. So I'll lower those temperatures by about 5 degrees. Expect high temperatures generally in the mid 30s. A few upper 30s are possible along the I 91 corridor.
Finally for Monday, a chilly winter's day is in store. With plenty of sun and high pressure overhead, I see no reason to stray too far from temperature guidance. Expect highs generally in the 30 to 35 degree range, except perhaps a touch warmer along the I 91 corridor.
Looking into the long range, although there could be a cold shot from time to time, temperatures generally look to average above normal as far as the eye can see. However, we are entering the heart of winter, and even above nornal temperatures with a well-timed storm can yield wintry precipitation, especially in the northern parts of the state. The pattern does look to continue active and stormy, so stay tuned!
Now, let's take a graphical look at systems slated to affect the area in the next week. Since there is only one significant system affecting the area this week and no record breaking temperatures, I'm only going to post one map. This map, valid Friday morning around dawn, captures the evolution of that system very well. You can see precipitation ongoing across the state at that time, with more moving in. You can also see the break headed to the region with more rain on the other side of the break.