Friday, July 05, 2013

Thunder Chances Increase Sunday

We should be able to coax a couple of dry days, although humidity levels won't be all that tolerable and if you exert yourself outside you're likely to end up pretty soaked from sweat.  Friday and Saturday will likely be dry but summery as we get our third run of 90 degree weather in place.

However, the Bermuda High responsible for the heat and humidity is going to flatten out a bit as we work into Sunday and Monday.  It doesn't mean it's going to cool off appreciably but it does mean a return of higher moisture and thunder threats for late Sunday and Monday.  The GFS (below) shows Sunday afternoon's depiction of scattered thunderstorms across parts of Pennsylvania northeast into New England.  As of now, it looks like a scattering of storms is a reasonable bet.

GFS Surface Depiction For Sunday 5 PM.

However, the threat for heavy rain does exist across the Mid Atlantic as a stream of moisture pushes northeast through the region. Atmospheric moisture will not be as high as it was earlier in the week but PWAT's (one of the moisture indicators) will approach two inches on Sunday afternoon and remain relatively high for much of the first half of next week.   Anything that does develop on Sunday could produce localized's something that we will keep an eye on through the coming days.

The thunder threat for us and South Jersey may be a bit higher on Monday than Sunday (Sunday's threat may be higher for the western burbs and points west)...but we will have to keep an eye on both days for the possibility of storms developing and impacting parts of the region.