July 21st, 2011 Forecast

The hothouse of the last few days will become a full fledged sauna over the next three days, with a run at 100 degrees on Friday...perhaps even Saturday...in the Delaware Valley.   The temperature alone is hot but with dewpoints that are poised to be in the 70's more often than not through Saturday we could see heat index values that could reach or perhaps exceed 110 in the worst of the heat on Friday.

Despite the presence of an isolated storm or two in parts of the region this afternoon and evening, most of the region is setting up for a warm, muggy night with low temperatures in the 70's across the whole of the region.   Light winds will add little relief to the mugginess.   Sunshine should dominate on Thursday, with only a few pop up clouds around in the afternoon.   High temperatures should range from 94-98 inland, 83-86 at the immediate Shore thanks to the presence of a south-southwest wind...once you get a couple of miles inland temperatures will be just as hot as we expect to get in Philly.

Eventually the heat will ease -- we promise!   Friday does look to be the worst of the days although Saturday could be just as nasty as heat index values could reach 110 in the worst of conditions.   Thunderstorm chances should increase through the weekend as a weak frontal boundary tries to slip south late Friday into Saturday, holding over the region until a more potent cool front moves through on Monday with a more widespread thunder chance.