The first batch of heavy showers with embedded thunderstorms is now pushing northward into the region. This will be the first of many waves of extremely heavy showers with scattered thunderstorms that are expected today.
I cannot emphasize this enough - the FLASH FLOOD THREAT today is EXTREMELY HIGH. Rain totals of 2 to 3 inches are likely across all of Western and Central Mass.
In addition, rain totals of 4 to 6 inches likely in an area from the lower Pioneer Valley of Western Mass eastward to the Worcester Metro. This includes areas near and south of the Mass Pike from Springfield to Auburn and also includes areas in the western Worcester Hills and across the I-84 corridor, including Sturbridge, Brimfield, Brookfield, Ware, Spencer and Rutland.
These extremely heavy rainfall amounts, which will include hourly rainfall rates of 2 to 3 inches will lead to the potential for very significant amounts of flash flooding of streets, highways, underpasses and areas of poor drainage. Basement flooding is also quite possible for many given the additional rainfall on already extremely saturated ground.
If that wasn't enough, some of the thunderstorms today will likely rotate given the moderate amounts of low-level wind shear that's available. This means there is the potential for a couple of tornadoes across the region, mainly from mid-morning into the early afternoon hours.
Again, I cannot stress enough that the flash flood threat is extremely high today and widespread very significant flooding is likely across the entire area.
Many more updates will be sent out as needed.