NFL Weather Report: Week 8

So, about that rain last week.

We at least noted the possibility of the games being affected in last week’s report. Our initial assumption was that FedEx Field would be covered prior to the start of game, limiting the amount of time the field could soak up any rain.

It didn't help.

Precipitation continued to pour all afternoon, leading to the 2019 Mud Bowl featuring a total of nine points. Excellent.

We also saw the same thing occur three time zones over from Maryland. Seattle’s broadcast began with the field under a constant drizzle. It led to slips and a fumble changing the tide of the entire game.

Week 7 demonstrated the downside of poor weather conditions with weak forecasts. The data suggests minor impacts can be overcome by the players: removing gloves, switching out cleats, etc.

But those adjustments come after negative outcomes -- dropped passes, the ball inexplicably slipping from your hands, sliding across the field instead of cutting -- all events we can understand after the fact but are tough to plan for ahead of time.

With more rain in the forecast for Week 8, we’ll be providing another update on Sunday ahead of the early kickoff for more info to help with last-minute roster decisions.

Overview

Below are the games with weather concerns headed into Week 8.

Games Impacted by Rain

New York Jets (17.75-point implied total) at Jacksonville Jaguars (22.75)
Cleveland Browns (16.25) at New England Patriots (29.25)
Philadelphia Eagles (20.5) at Buffalo Bills (23)

Let’s start here.

Our weekly reference table now not only serves as a gauge, but we’ve seen what happens in games where these precipitation rates actually occur. Historical observations from Week 7’s games measured less than 0.01 inches per game in Seattle. But we saw what sustained rain can do in just a few, but significant, plays. The Washington-San Francisco game averaged 0.01 inches per hour for its entirety, leading to the Slip ‘N Slide contest during the game.

With more information, we can adjust our expectations on the forecasts in Week 8.

Both the New York-Jacksonville game and the Philadelphia-Buffalo game have hourly precipitation rates projected at an average of 0.02 inches per hour. Showers aren’t expected in northern Florida until nearly noon, reducing the chance of the field being impacted prior to kickoff. However, conditions will be much worse up north.

Rain is expected in western New York as early as Saturday evening. They’ll persist throughout the night and taper off by game time. League protocol states that the field must be covered by a tarp the night before a game and removed 90 minutes prior to kickoff. While this will shield the turf for most of the evening, the rain prior to and during the game will create similar conditions to Week 7. The artificial ground will help with draining, causing less mud, but slips and cleat switching should be expected.

The Browns-Patriots game carries much more concern. A precipitation rate of 0.09 inches per hour is expected throughout the game with a steady buildup throughout the morning. It’s likely that a tarp won’t be applied to the field until late, since showers aren’t expected until mid-morning. Regardless, fantasy managers are encouraged to check the forecast ahead of the game.

Luckily, Tom Brady's lengthy career provides a suitable sample of games in similar conditions. While he’s averaged 35.3 passes in the rain, his range goes from 21 attempts (and 8 completions) to 65 attempts. His completion percentage in those games has fallen below his seasonal average 42.9% of the time, and he’s crossed the 300-yard mark at the same rate. It’s possible that because about 20% of these games have come in the final few weeks of the regular season, Brady wasn’t required to put on a stellar performance.

In addition, a light wind is expected that will cause additional problems with Gillette’s open stadium section. With these two elements combined, storms of this nature should give most fantasy managers pause as they plan for this game.

Games Impacted by Wind

Carolina Panthers (18.75-point implied total) at San Francisco 49ers (24.25)

Anything above 15 mph starts to raise the level of concern. Kickers on either side of the ball should be swapped for other options if possible.

But we’re mostly interested in the quarterbacks. Mostly. Jimmy Garoppolo was recently recommended as a drop candidate, and Kyle Allen, despite his QB wins, hasn’t topped 250 yards passing since his first start against Arizona. Now, Allen faces a San Francisco defense that’s ranked second in Adjusted Defensive Passing Net Expected Points per play behind only New England. And, of course, it’ll be windy.

The easy drawback to this game is the wind’s effect on deep passing. That’s generally true. A quarterback’s throwing velocity, along with their ability to provide proper touch, will also factor into a pass over 15 air yards.

But Allen and Garoppolo are tied at 24 attempts a piece within that range. That's tied with Marcus Mariota and Teddy Bridgewater. Deep passing isn’t in their repertoire. Allen’s aDOT on the season is 8.0. Garoppolo’s sits at 6.7. And combined with each opposing defense ranked first and second in sack percentage, neither passer will have much time to uncork a deep shot, either.

So while the northern 20.5 mph wind will create a slight crosswind due to the stadium’s 151.7-degree azimuth, both offenses work best in the short to intermediate range anyway. Their tendencies should create a natural deterrent against passing into the wind, negating most of its effects on the passing game.