Severe weather moved across the area this afternoon and some continues this evening. There is very heavy rain along the Mass Pike and this will continue through the early evening. Some areas will see 3 inches of rain and street flooding. I don’t expect much more severe weather, but very strong storms are likely in areas mostly from Boston south and west. If you are not using twitter yet, give it a try. I update the forecast regularly, give garden tips and will answer short questions. You can find me on Twitter at @growingwisdom
We have seen a lot of severe weather this afternoon from Boston north and for the rest of the day the focus will be south of Boston towards Rhode Island and the Cape. The heat the past week has been caused by a large high pressure area that is finally going to relax its grip on the northeast and Midwest. Whenever you have a change in air masses there is the risk for showers or thunderstorms and that risk will be with us for much of the afternoon and evening today. Fine weather returns later Thursday and by Friday morning it will be refreshing Canadian air for a few days. If you are not using twitter yet, give it a try. I update the forecast regularly, give garden tips and will answer short questions. You can find me on Twitter at @growingwisdom
Storms were prevalent at mid-afternoon as you can see above across the area. That line continues to move south. A cold front will cross the area today and usher in a new air mass. All types of fronts have something called lift associated with them. Lift is simply a term meteorologists use to describe what may happen to the air. Basically,the air goes up with lift, remember, gravity wants to keep it down. When air rises, it cools, condenses and forms clouds and sometimes precipitation. Lift is one of the most important forecast elements to get right. If you miss lift and it occurs, you end up with clouds and preciptation. If you forecast lift and it doesn’t happen, your rain or snow forecast never materializes. Today, our lift is being provided by two things. The first, the sun heating the air and causing it to rise or lift.
The second, the cold front, (blue line on map) will push cool air into the hot air and help lift the air. These two mechanisms are going to work together this afternoon to bring us the chance for storms.
The chance of storms increases if the air that gets lifted is warm and humid. So the later in the day we get, the warmer the air. The issue for today is when does the front, the other lifting mechanism pass? If the front goes by too early then we won’t have enough heat built up to get many storms. The storms will form ahead of the front and it may be that we see them get strongest south of the Boston if the front moves through Boston too early this afternoon. The front is moving very slowly and will take over 12 hours to move from Nashua to Nantucket. I will update this blog as needed about the storms and the front.
Whatever happens today the cooler air will start to move through overnight and by Thursday morning much drier air will great most New Englanders. Tomorrow the cold front will still be very near the south coast of the area. Since the area of lift will be so close, clouds will be slow to leave the Cape and Islands on Thursday. It may be that many areas hold the clouds much of the day.
A severe thunderstorm watch remains in affect until 9PM for much of the area. Humidity will be high in southern New England but drop all afternoon to the north. There, highs will be in the 80s, while in the Boston area many spots will reach for 90F again. (that will be 8 days of this heat for many) We are already seeing large cumulonimbus clouds, the forerunner of thunderstorms, forming. We have the risk for showers and storms through midnight. Overnight it will depend on exactly where you are as to whether or not it is comfortable. Most areas start muggy and warm, however, Chelmsford, Lawrence, Fitchburg and other towns along the New Hampshire border will be drier and cooler by Thursday morning. That dry air will push south all day Thursday.
Highs on Thursday will be in the 80s again, but without humidity.
Friday and the weekend
The front that passes through today will get hung up to our south on Friday. There will be an area of clouds and rain that may try to skirt the south coast of New England Friday and keep it cloudy and muggy. Finally, this area will move south far enough for the weekend to bring a return to sunshine. Friday’s forecast is going to change several times in the next day so stay tuned. I do think the humidity will return later Monday for a day.
A quick peak at the weather next week shows a brief warm-up Monday before another front crosses the area for Tuesday. I don’t see any prolonged 90F days in our future which is a good thing. We do need rain badly and many towns have expanded their bans so be sure to check your local area for when you can water, if you can at all.
Gardening this week
There has been late blight on tomatoes reported in a few places across the area including Middlesex county. Late blight is horrible because it is tough to control and will kill your tomato plants. In 2009 the blight hurt millions of dollars of the tomato crop. This year, it remains to be seen just how bad the blight is going to turn out. I have it on some of my tomatoes and have been treating aggressively. Here is a video about tomato blight below.
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