This weekend we have a somewhat unusual, for the time of year, since a weather system is on the way. This will bring steady rain and wind to the area, mostly tomorrow night.
One of the more important pieces in the formation of mid-latitude, non-tropical storms is a strong temperature contrast. These types of storms are the ones you see on the weather map with the L, representing low pressure.
These storms generally track west to east with the jet stream and are most prevalent in the cooler months. Fall, winter, and early spring are a time of the year when it can be very warm over the southern part of the United States and bitter cold here in New England. In the summer, the difference in temperatures north to south are small, and therefore, these types of storms are much less common.
Generally, the rainfall we receive between about mid-June to mid-September is in the form of showers that are a result of frontal systems crossing the area or from warm and humid air being heated and building into thunderstorms. Rainfall can also come from tropical systems, similar to what occurred on July 4 last year or Irene back in 2011.
This weekend, a storm will move out of the Ohio Valley and to the west of New England. It will bring a windswept rain to the area, especially overnight Saturday and during the first half of Sunday. As the storm moves into Canada, the rain will end, and some clearing might even take place later in the day.
A return to drier and warmer weather is likely Monday, but there will be other opportunities for showers during next week.
Showers are pushing off the coast, and there is a clearing moving southward this morning. I do expect a decrease in clouds as the day progresses. It won?t be humid and with highs in the low to mid-70s, the afternoon looks great for most outdoor activities.
It will be very comfortable for sleeping overnight with some of the cooler spots falling into the 40s, most areas stay in the 50s, which is still an open window kind of night.
It?s not going to be bright and sunny, but it won?t rain most of the day either. If you get up early, there will be some sunshine, but clouds are going to quickly increase and the sunshine will fade. Steady rain will begin to spread eastward from southwest, reaching far western New England in the afternoon or early evening, but overall rain should not start in the Boston metro area until a few hours after sunset.
These systems can speed up a bit, so a few rain showers ahead of the main batch of rain aren’t impossible. This means although the bulk of the rain falls Saturday night and Sunday morning, some showers could fall from roughly 4 p.m to 9 p.m.
Winds pick up Saturday night making for a windswept soaking rain late at night and into Sunday. It will continue to feel cool for late June.
As the storm system moves north the rain will end. I don’t expect skies to clear, but the bulk of the rain will be over. Everything will be wet, lawns, gardens, etc., so just keep that in mind. It won’t be warm either with highs struggling to reach the 70s.
The weather turns typically warm next week with a return to more sunshine and highs in the upper 70s to lower 80s much of the time. There may be additional opportunities for showers, but nothing that indicates a washout.