Currently: A basically "empty" weather map in our part of the world. Strong high pressure (for this time of year) stretches from Rockford, IL, to right over our area. This ridging is why the next few days will feature pleasant weather, and since the air mass can be traced to the Great Lakes and not Bermuda, it will be warm, not hot, and dry, rather than humid.
Tonight: With clear skies and light winds, tonight should be as good a radiative cooling night as one could ever expect in this area. Lows should range 50 to 60.
Tomorrow: A sunny, fair day... what more can be said? Highs 80 to 85. It is conceivable that one or two spots in the I 91 corridor surpass 85.
Tomorrow Night/Thu: Generally more of the same. It could be a degree or two warmer on Thursday and humidity will begin to increase late as more of a return flow sets up.
Long Term: (the weekend and beyond): The weather will deteriorate as the weekend wears on. A cold front will approach the region. However, as the front approaches the Bermuda High will already be in the process of retrograding and strengthening. Therefore, this high will provide resistance and cause the front to stall. It will be nearly impossible to try to time the various waves of showers and thunderstorms that ride up the stalled cold front, but suffice it to say, as has been the theme this summer, heavy rain and localized flash flooding will be possible with any training cells. Taking a cursory look at the atmospheric setup, it does not really scream severe weather outbreak to me. However, we just had a few of these setups the past couple of weeks and they all overachieved in that department. So I do not want to say we aren't going to get severe thunderstorms. All this said, let's try to figure out the dailies.
Friday: I'll keep Friday dry, but with increasing cloudiness and we'll keep most of the shower and thunderstorm activity to the SW of the state with this package. With cloudiness and some onshore flow, temperatures will be cooler, in the mid to upper 70s.
Saturday: Waves of showers and thunderstorms ride up the stalled cold front. It probably will not rain every second, but it should rain, possibly heavily at times, for much of the day, especially mid afternoon onwards. The morning *MAY* turn out dry, depending on how far the front is. High temperatures should be in the mid to upper 70s.
Sunday: This looks like the biggest washout of the weekend. By then, the front will be closer and waves of showers and thunderstorms should be training across the area. Temperatures are very tricky on Sunday. The air mass will be significantly warmer overhead than that of Friday and Saturday. If there are any breaks in the precipitation, especially if there is any sun, could see temps surging upward quickly. (Of course, that would only serve to develop more heavier showers and thunderstorms). I'll go with a mostly rainy solution, as mentioned, but owing to the possibility of a break in the clouds here or there, I'll go a degree or two higher on temps, with 75 to 80 degrees expected.
Monday: I will optimistically go with a clearing trend and assume that any lingering showers and thunderstorms end by Monday morning. However, there are some models that keep showers and thunderstorms going. The ECMWF model, most notably, develops a coastal wave along the cold front. I am adding a "model notes" section at the bottom of this disco, and I hope that my coworkers here at SCTWX, as well as any hobbyists and meteorologists who read this, follow the guidance, because our two most important computer models are showing notable biases right now. Since I will assume that it will not be raining all day on Monday and that there could be some breaks of sun in the afternoon, I'll go with 80 to 85 for temperatures.
It looks like Tuesday should turn out very similar to this Tuesday, if not a tiny bit warmer and drier. Highs should probably be in the mid 80s, although it could turn out a touch warmer in the I 91 corridor. Humidity levels should be low and there should be plenty of sun.
Looking into the long range, once again, and I don't know how many times I can repeat this in one summer, it could very well turn out that we have a 2 or 3 day break with nice weather, followed by another several-day long unsettled pattern. Wash, rinse, repeat.
Now, let's take a look at some of the systems affecting our area in the upcoming week... for now, I am going to post Sunday's training thunderstorms and a look at the CPC long range outlook. You can see on this map that the frontal rains cover much of New England, and also extend all the way through much of Pennsylvania, and even down to Kentucky! This is why it is going to become hard to exactly time the various waves of rain!
Model Note: The GFS has been running too warm. That feels weird to say, since the GFS has been known to have a cool bias, but it has been running warm, especially the gridded data. I'd like to think of the GFS data as the absolute ceiling for how warm it could get.
The ECMWF has been showing a bias for blowing up storms and then tracking them much too far to the west. This is why it was discarded for Monday with this package.
It will be interesting to see if these trends continue into the winter.
That's all for now! Enjoy the rest of your week!
-GP!