If you look at averages in New England, the period from the middle of June until the middle of August is generally filled with warm and somewhat humid weather. We don’t usually have full days of rain and it’s rarely very chilly. There are some exceptions to this of course. The mid and Downeast coast of Maine often has fog and cooler readings than their inland counterparts. The highest peaks of the White Mountains are generally cooler and can be shrouded in clouds and Cape Cod and the south coast of Southern New England enjoy a cooling affect from the ocean which can also often bring morning low clouds and fog.
If you are taking a vacation in New England, these microclimates are an important piece of the meteorological puzzle. When you see the forecast this week for warm and humid conditions, there are going to be some exceptions to this and also areas where it’s quite a bit warmer than others.
Areas closest to the coast are often cooler during the day, but actually stay warmer and more humid at night. If you have a beach house and leave your towels outside at night they can be quite wet in the morning. Inland mornings can be 5 or 8 degrees cooler than those in the larger cities, but some inland areas can also experience 3 or 4 days near 90F, while the coast is only in the mid-80s or even cooler. Each area has their own advantages and disadvantages depending on your preference and perspective. I tend to favor anywhere it’s cooler in the summer because I am not a fan of the heat.
Today, temperatures over northern Maine are going to warmer than many areas south of them. Notice readings are near 90 there while it’s it in the mid-80s south of there. The way the pressure systems are oriented at the beginning of this week is bringing the warmest air into that part of New England while a southerly flow will allow slightly cooler air to penetrate southern New England.
Showers and thunderstorms start entering the forecast in some areas later this week, while others remain dry. As the humidity increases, especially on Tuesday and Wednesday it won’t take a lot to kick off a shower, but we do need some mechanism to lift the air enough for this to happen. The sun itself can heat the ground and in turn the air starts rising to form clouds and perhaps a shower or two. Fronts are good catalysts for showers and there will be one of those coming through towards the second half of the week.
I’ll be updating the forecast @growingwisdom on Twitter.
The map below shows the probability of any rain today. It’s virtually zero. Notice back through western New York the chance increase over 50%. This area is going to come east this week and eventually increase our risk of thunderstorms. The risk will go up first over western New England and last on Cape Cod.
Presently, Thursday looks to be the day with the highest risk of showers. Of course, this is also the day before the 4th of July holiday. If the front forecast to cause the showers keeps moving, as some models are saying, the 4th itself will be sunny, warm and dry. However, other models are showing the front moving so slowly showers and storms continue into at least the morning of the 4th. Towns with fireworks on the 3rd may have to postpone or cancel them, but those on the 4th should fare much better. Of course this is all subject to change, it’s only Sunday.