Wednesday, June 27, 2012

Fry Day May Start Thundery

Our second foray into extended summer heat is approaching, with 90's a pretty solid bet for Philly tomorrow and the potential for high heat and humidity as we get into the upcoming weekend.  Excessive heat watches are out for the Delaware Valley for Friday (er, "Fry Day") through Sunday as the combination of heat and humidity may drive apparent temperatures to or over 100 degrees in the region.   We could end up seeing a repeat in terms of temperatures to what we saw last Wednesday through Friday around here this weekend.

There's still a fair bit of difference between the Euro and GFS over how hot it gets in this upcoming stretch -- the GFS still tries to paint a frontal boundary overhead that is a bit more active with thunderstorms nearby, with the Euro suggesting the front ultimately lies a bit farther north and is a bit less active.   That said, there are a couple of time frames that seem to be prone for a bit more thunderstorm activity.  First, Friday looks to bring a chance of some storms as hot air builds in...the storm chances look to be a good bit higher in the morning hours as a warm front crosses the region, with a few isolated storms possible in the afternoon.  However, Friday's thunder threat seems (as of now) to be one of those "early morning specials" that wake some people up around 4 AM with loud rattles of thunder.  The second chance would be on Sunday with a wave of energy crossing the region as the frontal boundary slips back to our south a bit.


In terms of records, Friday doesn't offer a great chance of reaching or breaking any record highs -- Wilmington and Atlantic City offer the two locations outside of the Poconos with the "cheapest" record highs to set (98 for both).  If the hotter guidance sets up (Euro), we could approach the AC and Wilmington record highs but odds favor most of us not getting into record territory on Friday.  Records through Sunday are generally in the upper 90's or low 100's so breaking records may ultimately be pretty tough to pull off.