The Election Day Weather Forecast: Who Will It Favor?

Via Cliff Mass’ Weather blog,

I got a call today from a political science professor from California:  he wanted to know how to get reliable weather forecast information for next week because weather can favor one party over another.

I helped him, but this got me thinking about the weather on election day, particularly since we are now close enough in time to have some skill.

I was familiar with a number of studies that have been done on this subject, and their suggestion that bad weather favors Republicans (see an example below).

So what do the latest and best model forecasts predict for election day?

Since my blog readers deserve the best, I examined the world-leading guidance from the European Center model.

The forecast for election day over much of the U.S. is extreme….. extremely pleasant, with minimal storminess and precipitation.

To give you the best possible forecast let’s examine the European Center ensemble model predictions in which they run their model 51 times, each slightly differently,  The average or mean of  these ensemble forecasts is usually a good prediction.

The ensemble-mean upper level (500 hPa, about 18,000 ft) weather map for 11 AM PDT shows a HUGE area of high heights/pressures dominating nearly the entire U.S., while a trough of low pressure/height is offshore.    Such a pattern will bring warmer than normal and dry condition for the western two-thirds of the U.S.

To show his, there are the temperatures forecast for the same time. Toasty in California, the southwest, the central and southern Plains states, the Gulf Coast and Florida.  The only locations that will be below freezing will be northern New England and New York.

Precipitation that day?  Almost nothing except for a few sprinkles in New England.  Even Seattle will be dry

Considering this forecast, the classical papers, such as the one noted above, would suggest an enhancement of Democratic voting.

But I suspect there are some surprises ahead.   How will the COVID pandemic and huge numbers of mail-in ballots change the story?  The percentage voting on election day will be much smaller than normal.

Trump supporters are probably different that the Republican voters of 20-30 years ago.  And can one really trust telephone-based polling?  Many people are solely using smartphones and conservative voters may well be fearful of expressing their honest views to someone that calls their home out of the blue.

One thing is for certain:  the weather this weekend looks quite pleasant here in the Northwest–a perfect time enjoy the fall colors. 

A pleasant way to forget the election for a few hours.