Tuesday, July 02, 2013

As Storm Chances Dwindle Later This Week, Heat To Build

The interaction of a relatively deep (by July standards) trough and a relatively strong Bermuda High are resulting in the pattern we've been stuck in for a while.  The pattern is showing signs of transition in the coming days.  Two things will happen and the result will be less rainy weather, but also hotter weather as the payback.

First, between now and Saturday you'll notice the trough in the Ohio Valley weakens.  This weakening starts to take shape tomorrow and fully carries out by Wednesday.  The upper level trough also is forced back to the west as it weakens, thanks in part to a strengthening Bermuda High (factor number two).

By Saturday, you can see the influence of the Bermuda High along the East Coast, with a strong ridge and surface high tandem helping to pump in humidity and heat across the East Coast.  This will suppress most of the thunderstorm threat...

...but probably not completely eliminate it.  Modeling does indicate a stray storm or two possible on Friday, Saturday, and Sunday afternoon.  However, heat will build and temperatures will climb back into the 90's for the end of this week and the beginning of next.  This will be the longest run of heat so far this year (and perhaps the longest run of 90+ heat all year)...it's possible we go at least six or seven days at or above 90.  It will also be quite humid thanks to the oodles of rain that have fallen across the region over the past week and will fall over the next couple of days.

The plume of soak will work west and become a bigger issue in the Mississippi Delta and western Ohio Valleys although we may remain under a thunder threat of sorts each afternoon. Those storms will be more scattered, less widespread, than what we dealt with yesterday.