A Yellow Alert is up across our region as we have the threat for flooding and flash flooding Friday due to the remnants of Debby. Flash flooding occurs when a lot of rain falls within a short amount of time and the ground can not soak it up quick enough. This is the recipe we have on Friday, as there will be tropical moisture and downpours falling across our region that could dump a lot of rain within a short amount of time. The greatest threat for this will be for areas just east of Rochester.

With that said, according to the Northeast River Forecasting Center, rain needed within most of our viewing area counties within one hour to cause flash flooding is around 1.5 inches. Rain within three hours to cause flash flooding is just about less than 2 inches. That is a lot of rain needed, but with the tropical moisture in place we could see rainfall rates exceed 1.5 inches an hour at times. These rainfall rates will not be widespread, but they could fall across our region Friday morning and Friday afternoon increasing the threat for flash flooding in those areas that witness the intense rain.

The good news is that Debby’s remnants will be quick moving and that rain will not sit over areas for a long period of time, but even with the quick moving system areas that see the most intense rain will likely wind up with rain totals between 2 and 3 inches, if not more, before things are all said and done Saturday morning.