Currently: High pressure is sprawled across the I 95 corridor. A warm front was over Northern NYS. A clipper low was over Lake Superior- this is too far north to really bring any precipitation to our area. A trailing cold front was near Saint Louis. This cold front will ensure our area another very chilly weekend.
Tonight: Temperatures could be a bit tricky tonight, due to varying levels of clouds and wind. So areas that usually radiate could see hour to hour temperature fluctuations. With no real clear signal of which way to go, I'll split the guidance and hedge a bit toward the cooler guidance sets. There should be a fairly wide temperature distribution tonight. Lows should range from the mid 20s to the low 30s. However, some locations in the NW Hills may reach the lower 20s. While it's not out of the question for the immediate SE coast to stay in the mid 30s. Although no measurable precipitation is forecast, I would not be shocked if there was a passing flurry up north and passing flurry or sleet shower in the south.
Tomorrow: Tomorrow should be the warmest day for a while, as westerly flow allows warmer air to move in ahead of the cold front. With lots of sun and really nothing going on, I'll go right with the guidance, which means highs within a couple degrees of 50.
Tomorrow Night/Sat: Temperatures will drop quickly behind the front tomorrow night. It's not a great "radiative" night because of winds staying up, but lows should be in the 20s everywhere, with a usual north-south gradient. I am going warmer than guidance for the time being with Saturday's highs with a good deal of sun. However, it should be noted that guidance has trended cooler and it is possible that this is correct. Sometimes models do underestimate cold air until the last moment. For now, I'm going to call for highs in the upper 30s on Saturday, but later crews may want to trend this downward. I just want to avoid flip-flopping for now. Regardless, with winds gusting up to 35 MPH at time, it will feel even colder!
Long Term (Sunday and beyond): There are two systems of interest in the long term. The first is centered around Sunday night into Monday, with the next centered around Wednesday, At this time, a model consensus is a brush on the area with both of them, but models tend to trend west if anything with time. The first system bears watching as some precipitation with it could be wintry, especially away from the coast.
First, temperatures will start off very cold Sunday morning. Another morning with near record lows is possible for some areas. There will be a wide range in low temperatures Sunday morning ranging from near 10 in the NW Hills, to the mid 20s in coastal New London County. Clouds may increase toward dawn, but I think they'll be high/thin enough and not arrive until late enough as to not impact low temperatures very much! Even so, I went a degree warmer than most guidance to compensate for this possibility.
Now, for the coastal low possibility, If we get precipitation in this area, which I wouldn't call a sure thing, but odds have increased some, especially E of I 91, the timing window looks to be between Sunday evening and Monday night, with a potential break centered around Monday afternoon. The first round of precipitation is where we have the most concern for frozen precipitation. Models are showing a sleet setup for pretty much the entire state. RIght now, the highest chance for accumulations would be in Tolland and Widnham counties, because precipitation will be heavier and this would occur simultaneously with colder temperatures at the sfc. The second round of precipitation should be rain, but sfc temperatures may be cold enough to allow for some pockets of freezing rain across the far north. This all needs to be watched.
As for the storm on Wednesday, right now models have this storm too far east to bring anything but light precipitation to the state, with most of the action being east of I 91. However, models have just begun to trend west with the first system, so it wouldn't surprise me if they did the same with the second system. Thermal profiles once again may support sleet, so this is another system that should be watched!
Now, for temperatures in the long term: I went fairly close to guidance through most of the long term, with only a few tweaks here and there to bring temperatures in line with surrounding forecasts. I did go a bit cooler than guidance on Monday and Thursday. On Monday, I went cooler because precipitation will be falling, and on Thursday, I went cooler because winds should still have more of a northerly component to them than models currently indicate. But guidance overall looked fairly good in the long term.
So here's what you should expect for daily high temperatures through the long term:
Sunday: Upper 30s, with perhaps a 40 degree reading or two along the I 91 corridor.
Monday: mid to upper 30s
Tuesday: generally mid 40s
Wednesday: mid to upper 40s (could be significantly cooler if the coastal low trends west)
Thursday: mid to upper 40s
Looking out into the longer range, blocking has begun to appear earlier on modeling today. This would lock in a much colder pattern than what was being advertised the past few days. Still it should not be as cold as what we just experienced. However, there has also been a trend in recent modeling to show a more active pattern than what we have been seeing. Interesting times are ahead!
Now, let's take a graphical look at the two systems slated to affect the area (or possibly affect the area) this week. First, let's look at Monday morning. This map is a perfect illustration of why I think Tolland and Windham counties stand the best chance of any accumulating sleet. They are far enough east, so that they're into the heavier precipitation, but they're also far enough north, so it's cold enough at the sfc.