November 01, 2012

Election Day Weather and Political Forecast

The pundits and pollsters are calling the presidential race too close to call.  They suggest even minor issues could decide the outcome.

Why listen to pollsters and pundits, when you can get the prediction of a profession that has more experience forecasting than any of those folks?

 I am, of course, talking about weathermen. 

Democrats Secret Weapon
So let me describe the weather on election day and predict who will win the presidential election.  Hey...if we can forecast a rare storm like Sandy, an election should be child's play.

We are close enough to next Tuesday to have a good idea of what the weather will be like that day.   Here is the latest forecast by the National Weather Service's GFS Model for 5 PM on Tuesday (sea level pressure plus the amount of rain over the past 12 hours).  Very Benign Forecast!  Almost no precipitation over the U.S, except for guess where?  No matter, we are used to rain and everyone knows which presidential candidate will win this state. And high pressure dominates the continental U.S. and most of Alaska.

So what about the vaunted European Center model...the model that nailed the Sandy forecast 8-9 days before?  Here it is (solid lines are sea level pressure).  Same story, with high pressure over much of the U.S.  Unlike the pollsters, meteorologists really know how to deal with uncertainty and as explained in earlier blogs, we use ensembles (many forecasts) to do this. The ensemble systems of both the U.S. and European Center models are consistent with the high-resolution forecasts described above. 

Bottom line: good weather on election day over virtually the entire country.  

What does that imply?

Obama will win.

Authoritative studies by social scientists have shown that good weather is helpful to Democratic candidates.  One well-known study by Gomez et al. 2005 (link here) entitled The Republicans Should Pray for Rain:  Weather, Turnout, and Voting in U.S. Presidential Elections found that the estimated number of voters lost due to precipitation significantly benefits the Republican Party.  The study is based on an impressive array of polling and meteorological data, with careful statistical analysis.

They state:  "we have shown that bad weather may affect electoral outcomes by significantly decreasing Democratic presidential vote share, to the benefit of Republicans".   And they make a compelling case that weather has decided some presidential elections. 

There are, of course, other weather elements that are helping Obama, such as his attentive efforts to help the victims of Sandy and his apparent turning of New Jersey Governor Christie into a implicit supporter.  But these fade compared to the nationwide effects of benign weather that are predicted by our modeling systems.

Furthermore, the suppression of votes in the Sandy destruction area will not change the electoral college totals since damage has been mainly in overwhelmingly blue states, but will greatly increase chances Obama will win the electoral vote but not the popular vote.

Bad weather, good friends.
Obama can make plans for his inauguration, the weather gods appear to be in his corner.


  1. True about this State, Cliff. If you can't win King County, but especially also Pierce, Snohomish,and Clark counties, you shouldn't waste advertising funds.

    As for the weather; still raining this morning. Just over .4 of an inch in the gauge. That brings my backyard to 2.80 inches, rounding down, over the last 72 hours.

    Now, would you whip up a few moderate windy periods for us, and maybe an early season cold push? Frost on the pumpkin at Thanksgiving is nice.

  2. I can buy in, except that the superstorm effects are ongoing and that in turn could affect Democratic voter turnout.

  3. Scrapy - Yeah, but the states with the worst impacts are not swing states by any stretch. That's why all of the "concern" in the media narrative about election impacts is a bunch of hogwash. New York and New Jersey are not going to have impacts sufficient to have them vote for Romney. The one state you might try to make that work on (Virginia) isn't nearly as bad in terms of damage.

    I think the weather conditions on Election Day would have a much greater impact.

  4. Surprised you did not mention Nate Silver, a professional forecaster with a similar level of passion and skill in the polls as you have in weather.

  5. I wonder what it is about Democrats (and liberal voting Independents) that have us staying away during bad weather?

  6. It would be hard to argue that conservatives aren't typically a little more fired up about the outcomes of presidential elections, particularly this one. A little bit of rain won't stop them.

    Fortunately the weather (and the weathermen) appear to have a liberal bias this year.

  7. Eric, in the study, they list three theories about what will affect voter turn out: "the socioeconomic status model, rational choice model, and mobilization model...No matter which of the theoretical models one favors...the common thread that runs through each is that the costs of participation are a major
    obstacle to citizen involvement. Likewise, the inherent assumption of the weather-turnout thesis is simply that bad weather adds to the costs of voting..." The idea is that the cost to the voter vs the benefit directly affects their motivation to vote. If the personal cost is too high they will not vote. Apparently those who vote Democrat are more affected by the increased 'costs' that inclement weather has on voting.
    Seems to me like a great basis to encourage early voting/mail in voting!

  8. The disabled and elderly are more likely to vote Democratic, and also more likely to have trouble getting to the polling place during bad weather. It's not a huge effect, but a difference of 2 or 3 percent can make a difference in a lot of races.

  9. We all know the results of Climate Change....But Is it possible that the "HIGH FREQUENCY ACTIVE AURORAL RESEARCH PROGRAM" "H.A.A.R.P" is responsible for damage to our ionosphere, and as a result "Global Warming". Thanks, Anne Murray


Please make sure your comments are civil. Name calling and personal attacks are not appropriate.

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