Extensive & Potentially Severe Flash Flooding Possible Across Western & Central Mass Wed Night & Thu

Summary: Extremely heavy rainfall associated with the remnants of Ida are likely to move in during Wednesday afternoon with the worst of the rainfall expected during Wednesday night into Thursday morning. Rainfall then comes to an end by Thursday afternoon. This rain is expected to lead to the potential for extensive and possibly severe flash flooding across all of Western and Central Mass. This is a situation that needs to be monitored extremely closely. Details: Light to moderate rain is expected to overspread the area during the late morning and early afternoon hours of Wednesday. As the energy and moisture from Ida crosses Southern New England, it will bring a slug of extremely heavy rainfall through the area that lasts upwards of 6-8 hours on Wednesday night. At this point, it appears that the heavy rain will begin across Western and Central Mass by about 8-10 pm Wednesday evening and then continue through the rest of the night before beginning to lighten up in intensity around the 5-7 am time frame Thursday morning. The rain is then expected to continue for a while on Thursday morning, albeit at a much lighter intensity, before ending during the late morning and early afternoon hours of Thursday. The rainfall totals are something that are going to have to be watched extremely closely. At this point, I’m thinking that rain totals may range from 1 to 2 inches along and north of Route 2 and from 2 to 3 inches across the rest of Western and Central Mass. Further south, rainfall totals of 4 to 6 inches are expected across central and southern Connecticut and this axis of this extremely heavy rainfall needs to be monitored as it could shift northward towards parts of Western and Central Mass, especially areas south of the Mass Pike. In fact, high resolution weather model data is painting a very ugly scenario of 3 to 5 inches of rainfall across a large part of Western and Central Mass. So, I think that isolated amounts of 4 to 6 inches are even possible at this point across Western and Central Mass depending on the location of the heaviest bands of rainfall. These rainfall totals are expected to lead to the likelihood of extensive flash flooding with the possibility of severe flash flooding. I am extremely concerned that we’re going to see extensive flooding in poor drainage areas and across urban areas, especially in metro Springfield and metro Worcester. In addition, flash flooding and washouts of roads seem very likely as well – so, use extreme caution if you’re traveling on Wednesday night and Thursday. In addition to the flash flood potential, we need to also keep a very close watch on the rivers and streams across the area. Many of the smaller rivers and streams are already at greater than 90 percent capacity, so it’s not going to take much to cause them to run out of their banks. This is a situation that I’m watching extremely closely and I’ll have updates for you as needed, especially if flash flood warnings start to be sent out by the National Weather Service.