Tuesday, July 09, 2013

It's Been Rainy...But

Philadelphia's seen a healthy amount of rain the past two weeks. Our region's picked up between two and five inches of rain...which is still quite a lot and in some places about 200 percent of normal.  Philadelphia in particular has picked up nearly three inches of rain in the past two weeks -- solidly above average.

However, some places have seen quite a bit more than us.  If you take a look at the graphic below, you can see the heaviest precipitation to average over the past two weeks has been across the Ohio Valley, Appalachians, and Southeast....oh, and California to average (but the average rainfall in California in June is rather modest compared to ours so we will focus on this side of the nation).

Chattanooga has had six inches of rain. Since July 1st.  Knoxville, TN, has picked up over seven inches of rain in the last two weeks, five of which fell in the last seven days.  Lexington, KY, has picked up nearly eight inches of rain.

Even Toronto has picked up over six inches of rain in the last two weeks, over four of which fell yesterday!

The cause of the heavy rainfall across the Ohio Valley, Great Lakes, and Southeast is the same cause of our heavy rains -- the return flow around the Bermuda High, a trough in the Midwest and Great Lakes, and the resulting gravy train of rain that pushed northeast through the Southeast, Ohio Valley, and into the Northeast.

The result?  Well, at one high school in Tennessee, a caved in roof.  This isn't to marginalize what we've dealt with in Pennsylvania but we're not alone in the rain parade this summer!

With the pattern over the coming days not far off from what we saw in the past two weeks, some areas will deal with more heavy rain and more flooding problems, especially if moisture from Chantal pulls towards the Southeastern coast.  The GFS suggests a Florida landfall on Sunday night into Monday, with the "consensus" of tropical modeling suggesting the center tracks pretty close to Florida by early next week, with impacts across the Southeast.  We'll keep an eye on the impacts of the storm system as it pushes quickly west-northwest over the next couple of days.