Summer's Unofficial End Brings More Rain

Last week was a rarity of us – cool, dry, and a tease of autumn at its finest.  Temperatures struggled to hit 80 a couple of days after Irene ripped it up locally with several inches of rain.  We’ve seen humidity creep back into the picture the last couple of days as a frontal boundary lurks to the west.  This front will cross the region later on tonight and Tuesday, bringing some heavier rainfall along with it as some moisture from Tropical Storm Lee gets pulled northeast along this approaching frontal boundary.

Rainfall should be moderate to heavy in spots, with the potential for as much as two inches across parts of our region.  While in normal circumstances a two inch rain event would just result in shoulder shrugging and umbrella grabbing, the fact that our ground is saturated and has little tolerance for absorbing this kind of rainfall means the potential for localized flooding is back in the cards for our vulnerable streams such as the Perkiomen, Brandywine, and French.   We’re not looking at flooding on the order of what was experienced during Irene but flood modeling suggests a two inch rain event in Montgomery County would probably be enough to lead to some flooding in some locations.

The week as a whole looks somewhat unsettled as Tropical Storm Lee’s moisture spins northeast in pieces, the first piece being Monday night and Tuesday and the second coming in for Wednesday.

There is some question about the second piece and where that ultimately tracks but another inch or two of rain could move through Wednesday and Wednesday night, keeping soggy folks on edge and preventing soils from drying out much.   This part is a bit more uncertain as it’s dependent on how much of Lee is pulled northeast along the front and how much moisture (if any) is left behind in the Southeastern US.  To compound the “fun”, Hurricane Katia is out in the Atlantic and computer modeling is suggesting that the storm could get relatively close to the Outer Banks of North Carolina late this week before turning northeast back out into the Atlantic.

Katia could bring a few days of “surf’s up” and rip currents at the Shore starting Wednesday and continuing through the weekend.

For now, the odds favor a miss in our region but it’s not a lock (yet) that Katia avoids us.