THE SAME MODEL BATTLE FOR A WEEK….
A week ago, I wrote about the rain chances for the Papal Weekend in Philadelphia. Some computer models showed rain moving up from the Southeast U.S., while others kept us dry. And after some time off, what do I return to? As the Four Tops once sang: “It’s the Same Old Song." The players are the same, and none have changed “teams." But one of the teams looks weaker, while the other has gained strength.
THE PLAYERS: “TEAM RAIN”
As it was a week ago, the main U.S. computer model, the GFS continues to show rain now from North Carolina to Florida moving up the coast for at least part of the weekend. But it’s not as far north nor as widespread as it looked two days ago. The Canadian model is similar. Now that we’re closer to the event, the shorter-range models come into play. A couple of days ago, the NAM (another U.S. model) was suggesting heavy rain Sunday. Yesterday it looked less impressive. And today the rain barely makes it up to Philly.
Here is a forecast map from the NAM for Sunday afternoon
Now look below at what the NAM was showing yesterday…..a much wetter solution:
“TEAM DRY”: BETTER RECORD-ADDED PLAYERS
Yes, the sports metaphors continue (forever, in my case). The other side of the computer model forecasts already has the top star in the game (the European model), and continues to add to their already impressive roster. On board now are the UKMET, the SREF, the RPM, and two others I haven’t mentioned in previous blogs: the JMA (Japan) and the NAVGEM (new U.S. Navy model). All show the southern moisture staying to our south. Well, at least south of Philadelphia. Southern Delaware and extreme South Jersey are still a close call.
Here is the NAVGEM forecast for Sunday afternoon:
That’s not even CLOSE to what the NAM has been showing. The NAVGEM keeps the rain farther south than any other model I’ve seen, but you get the idea-HIGH pressure just off the New England coast remains strong enough to hold off the southern moisture. It’s not a sure bet, but the odds-makers (me) have increased the point spread even more on the side of “DRY." There are about a million or so people who are rooting for that team to win, so they get to stay dry for the Papal weekend.
As we’ve seen many times before, the trends of individual models and/or the overall picture give greater confidence to a forecast. The trend is on the drier side, so I’ve lowered rain chances even more.