By Kate Bilo
CAMDEN, Del. (CBS) – Remember the first week of September last year? All the kids going back to school, Labor Day picnics and, oh yes, over 6″ of rain in four days thanks to the slow-moving moisture and circulation around what was once Tropical Storm Lee. This rain led to some of the worst flooding Central PA has ever seen.
Fast-forward to this year: the remnant circulation from what was once Hurricane Isaac sitting over the Ohio Valley, and the first week of September arrives with, once again, the threat for heavy, flooding rain. While the tracks of Lee and Isaac differ, the setup is similar – a slow-moving area of low pressure coupled with air that’s just laden with tropical moisture. This pattern leads us, once again, into the threat for flash flooding.
We started out Labor Day Monday with a drenching batch of rain moving through Chester, Montgomery and Delaware counties. Devault, in Chester County, clocked in with 3.5″ of rain Monday morning.
Then, Monday afternoon, the storms rolling across the state of Delaware produced suspected tornadoes and caused damage to homes in Camden, Kent County, and sent one person to the hospital. There were numerous reports of a funnel cloud in the area, a reminder that even though heavy rain is our biggest threat this week, any of these storms can produce severe weather in the form of damaging wind and tornadoes.
And this pattern isn’t over yet. As the low across the Ohio Valley slowly meanders up toward New England by Thursday, we’ll be in a very stagnant, sluggish atmospheric pattern – with nothing really MOVING quickly, the storms will have a tendency to sit in one spot for an extended period of time, dumping rainfall at the rate of 1-2″ per hour. This can lead to ponding on the roadways, small creeks and streams breaching their banks, and depending on where the storms set up, we may have to keep an eye even on some of the larger streams and waterways in the area through the midweek time frame.