Tropical Storm Isaac, expected to become a hurricane by midnight, could pound the northern Gulf Coast - including New Orleans - when it makes landfall late Tuesday into Wednesday.
The storm, which already dumped 10 inches of rain along western Florida and postponed the start of the Republican National Convention, is expected to create storm surges of six to 12 feet, to go along with Category 1 winds of 75 to 90 m.p.h.
Once it's over land it will lose strength but will continue dumping rain as it heads northward.
The projected path could mean welcome drought relief for East Texas and the Midwest, before what's left of Isaac heads toward New England.
Philadelphia could be along that path, but it's really too early to tell, said meteorologist Mitchell Gaines of the National Weather Service office in Mount Holly.
Current Philadelphia forecasts call for partly sunny skies Saturday, partly sunny (Weather Service) or chance of thunderstorms (AccuWeather) Sunday, and possible thunderstorms Monday (AccuWeather).
If Isaac does swing by, the likeliest timing seems to be that rain should hold off on Saturday, and possibly even much of Sunday - the dates for the two-day Made in America musicfest on the Parkway.
"We may get some moisture as early as Saturday/Saturday night, but as of now, Sunday night into Monday looks like the best period for rain with the remnants," according to the latest forecast discussion.
Bruce Springsteen fans might have more reason to fret, since the Boss' concerts at Citizens Bank Park are scheduled for Sunday and Monday at 7:30 p.m.
It won't be "a basinwide Lee type soaking," said meterologist Anthony Gigi, referring to last September's deluge from the remnants of Tropical Storm Lee.
For more on the forecast, go to Philly.com's weather page (http://weather.philly.com/US/PA/Philadelphia.html).
For more on Isaac, go to the National Hurricane Center's home page (www.nhc.noaa.gov) and click on the image of Isaac on the map.
Contact staff writer Peter Mucha at 215-854-4342 or firstname.lastname@example.org.