The weekend weather across southern Maine will be a split decision. Saturday is going to be dry, while Sunday, especially the morning, brings quite a bit of rain.

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.

The type of storm we have this weekend is more typical of the cooler months of the year. 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 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 4th last year or Irene back in 2011.

Friday
Lots of sunshine continues the rest of the day. 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.

Saturday
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 southwestern New England in the afternoon or early evening, but mostly should not start in Maine until after sundown.

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.

Sunday
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 by 2 p.m. 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 upper 60s to near 70 degrees.

Next week
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.