
With areas of moderate rainfall on the way on the order of 1-2" for many in southern Vermont and New Hampshire, I wanted to talk a little about flood potential. First, let me start by saying, I don't believe flooding will be a widespread issue by any means. Several rivers, will however, rise due to the rainfall, and one or two may come close to causing minor flooding.
First, here is a model forecast of the rainfall potential through Tuesday night in our region. Keep in mind, this is a model, and numbers will vary, but it gives a general idea of how much to expect and where the heaviest rain is forecast to fall.
The ground is somewhat wet due to rain in recent days, but as a whole the ground can easily tolerate 1-2" of rainfall over the long period of time the rain will be falling. I know this by looking at the flash flood guidance, which shows the amount of rainfall the ground can handle over a 3 hour period, mind you, to cause flooding. The key there is over 3 hours time...our rain will fall over more like a 6-10 hour period. Here is the guidance, showing most areas able to tolerate over 2-inches of rain. Some counties in western Vermont are highlighted yellow, indicating a slightly lower tolerance of 1.6"-2" before flash flooding would occur.
Finally, there are forecast models that show the expected river level rises due to the amount of rainfall in the forecast. I have not seen any rivers forecast to go into, even minor, flood stage. This is good. While several rivers will rise quite a bit, they should stay below the level that would cause flooding to property nearby. A couple of rivers forecast to rise to "Action stage", or rather high levels, but below flood danger, are the Sugar River near West Claremont, and the Otter Creek near Rutland.