Phillies playoff weather this weekend ‘is going to be great,’ forecasters say

For weather, Major League Baseball couldn’t have picked a better October weekend in Philly for a playoff series — and if you’re reading this, Nick Castellanos, please don’t forget your sunglasses.

Given that both the Saturday and Sunday games are scheduled to start at 4:08 p.m., the oblique sunlight streaming across the field might be especially challenging for right fielders at Citizens Bank Park.

Otherwise, the weather “is going to be great,” said Patrick O’Hara, meteorologist at the National Weather Service in Mount Holly, rainless with temperatures mostly in the 70s and light winds.

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The continuation of a prolonged dry spell should be good for at least something: Forecasters see almost no chance of rain during either of the games, or even so much as a rain delay for the first two games in the National League Division Series.

Any rain likely would hold off until the early morning hours of Monday, said Dave Dombek, senior meteorologist with AccuWeather Inc.

And unlike the recent run of gloomy days in which the winds were blowing off the cloud factory known as the Atlantic Ocean, the weekend skies look to be clear, as the breezes will be sailing over dry land masses, said the weather service’s O’Hara.

The game-time temperature Saturday is forecast to be in the mid-70s, about five degrees above normal for the date, and just a few degrees cooler on Sunday.

With the scarcity of clouds, shadows could be an issue, “at least for the first half of the game or so,” said Paul Dorian, a meteorologist with Arcfield Weather who is based in Valley Forge.

Shadows and light angles may be problematic for the outfielders, particularly the right fielders, but it is uncertain if they’ll affect the hitters.

The batter’s box will be in shadows of the stands on the third-base side since Citizens Bank Park is oriented north-northeast from home plate to center field. That’s close to what Major League Baseball calls the “desirable” orientation to keep the sun out of the batters’ faces.

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But do shadows give a pitcher an advantage? A Baseball Prospectus analysis of postseason games in 2019 found that shadows meant no difference in terms of the numbers of strikeouts, a result that probably had a lot to do with the quality of the pitching

The hitters may have a slight advantage on Sunday as the light breezes in South Philly will be blowing from the south, out toward center field at 5 or 6 mph, according to the weather service.

Alan Nathan, a physicist who chaired the Major League Baseball committee that investigated the home run binge of the 2017-19 period, has observed that a wind of just 5 mph can make a 15- to 20-foot difference in the flight of a baseball.

Dorian, who publishes a “Home Run Factor” index that uses a 1-to-10 scale to assess how park and atmospheric factors may affect ball flight for a given game, says that as of midweek, it appeared that the weather is unlikely to be a big player this weekend. Since the air will be on the dry side, it would be less buoyant than it would be when the air is holding more moisture on hot summer days.

Zack Wheeler, who is slated to start for the Phillies Saturday, and his counterpart on the other team, will have the advantage of a light breeze — again, 5 to 6 mph — from the north at his back.

And one other factor is likely to hold down the run total, said Dorian: “Wheeler is pitching.”