Have you checked the weather forecast in Philadelphia for Wednesday's Rockies-Phillies game? Weather.com shows thunderstorms in the afternoon and more of it at game time. This may force a postponement, and when the Denver Post's Jim Armstrong arrived in Philadelphia on Tuesday he tweeted that there was a flood watch in event for Wednesday.
The Rockies are no strangers to rainouts this season, though. They have had four so far (April 3 vs. Diamondbacks, April 12 at Mets, April 27 at Chicago and May 11 vs. Mets) and already made two of them up. Both came against the Mets, a doubleheader in New York and then in Colorado on an originally scheduled off day for both teams. The game against the D'Backs will be made up on May 24 as part of a doubleheader and the Chicago game will be played on June 27.
Entering this week, there were 26 postponements through the middle of May, and four more took place on Tuesday. According to Daily Baseball Data (May 16 entry), we are on schedule for 100 postponements, but that pace won't keep up during the summer months.