As pre-election opinion polling ended Friday, with a series of final surveys that showed a narrowing of the right-wing and Orthodox bloc’s lead over the center-left and Arab bloc — reflecting many of the trends predicted in The Times of Israel’s major poll — one key factor that could yet have a significant effect on the results is voter turnout.

What percentage of legally eligible voters will actually exercise their right to vote on Tuesday, which factors affect that turnout, and what impact could a high or low turnout have on the final result? Here’s how things could play out:

1. Weather won’t play a role

There are two competing arguments about how the weather on election day in Israel negatively affects turnout — one reasonable and one borderline ridiculous.

The first argument is pretty straightforward — the worse the weather, the lower the turnout. This argument is based on the assumption that if it’s cold and rainy outside, fewer people will leave their homes to go vote. Fewer people will wait in lines. Online weather sites suggest that this argument will be irrelevant this year, as Election Day is expected to be dry and sunny.

The second argument is based on the fact that Election Day is an official holiday in Israel. Most employees have the day off, and even those employees defined by the government as providing essential services — hotel employees, emergency and security personnel, bread factories, food delivery workers, and others — must be given the opportunity in their schedule to vote. Many argue that if the weather is good, families and young adults alike will use the holiday to travel, see friends, visit leisure sites, and do just about anything but vote. But it is very hard to believe, to put it mildly, that beautiful weather will lead to lower voter turnout, so unless there’s a surprise storm on Tuesday, weather should have no effect on turnout.

2. Lower turnout helps smaller parties

There are 34 parties registered for the elections, and the majority of them are unlikely to be represented in the next Knesset. For starters, a party must clear a threshold percentage of the popular vote in order to reach parliament. For elections up to 1992, the threshold was 1%. From 1992 through 2003, it was raised to 1.5% and since 2003, it has been placed at 2% of the popular vote.

In actual votes, the smallest party to make the cut in 2009 was the Israeli-Arab Balad party with 83,739 votes. The biggest party not to make it was the Green Movement-Meimad with 27,737 votes. In 2006, the smallest party to pass the threshold was also Balad with 72,066 votes and the Green Party was the biggest to not make the Knesset with 47,595 votes.

Here, the math works in favor of the smaller parties. The lower the overall turnout, the fewer votes a fringe party needs to clear the 2% threshold. So if turnout is low Tuesday, expect a smaller party such as Otzma Leyisrael or Eretz Hadasha to fare well. If turnout is high, these parties aren’t likely to make it into the Knesset.

3. Israeli-Arabs vote in low numbers

The Ministry of Interior publishes detailed election results, including the breakdown for 1,156 communities (yishuvim) nationwide. The Times of Israel looked at the 100 communities with the lowest turnout in 2009, the worst of which produced a pitiful 3% turnout of eligible voters. In these bottom 100 communities, 36% of those who did go out to vote chose an Israeli-Arab party, 16% voted for Likud, 14% for Kadima, 12% for Yisrael Beytenu, 7% for Shas, 6% for Labor, and 2% each for the National Union and Jewish Home parties. This data suggests a very clear conclusion — voter turnout is lowest in predominantly Israeli-Arab communities. According to an article published by Ynet citing Professors Avraham Diskin and Reuven Hazan of the IDC and Hebrew University respectively, turnout in the Israeli-Arab sector fell to 53.4% in the 2009 elections. It is unlikely that this trend will change on Tuesday.

4. Nationalist and religious Jews vote in high numbers

In the 100 communities with the highest 2009 turnout — from 85% to 95% — a staggering 33% voted for the Jewish Home and National Union parties (which only won 7 seats in the Knesset), 19% for United Torah Judaism, and 15% for Shas. Voters chose Likud at 12%, Kadima at 10%, Labor at 5%, and Yisrael Beytenu and Meretz at 2% each. The data suggests highest turnout amongst voters who support Jewish nationalist and Orthodox parties. As such, lower overall turnout will increase their share of votes.

5. History says turnout will be low, but perhaps a bit higher than 2009

In the first 20 years of elections in Israel, with the exception of 1951, turnout was over 81%. Then it started sinking. In the 1970s, ’80s, and ’90s, voter turnout fluctuated between 77% and 79%. In the last four elections — all held in the 2000s — turnout fluctuated between 62% and 68%, and turnout for the 2013 elections is likely to remain in this window.

If turnout was 62.3% in 2001, 67.8% in 2003, 63.5% in 2006, and 64.8% in 2009, what will it look like in 2013? In analyzing the direction turnout has gone in the last 19 elections, typically there is a pendulum effect. If in one election turnout is up relative to the previous election, in the next election it goes down and then the next election it goes up. Indeed, during the last 18 periods between national elections, turnout has followed this pendulum effect 14 times. Following this trend, turnout on Tuesday should be lower than 2009’s 64.8%.

However, while the pendulum effect was true 14 times, in four cases turnout continued to move in the direction of the trend of the previous election cycle. Israel has never gone more than 15 years of elections without an exception to the pendulum effect. Since 1999, turnout has followed the pendulum effect perfectly, suggesting that it’s time for the exception to kick in. So turnout, though still in that 62-68% framework, could yet be higher in 2013 than it was in 2009.

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Stephan Miller, cited by Campaigns and Elections magazine in 2008 as “James Carville’s young protege,” is an American-Israeli public opinion research analyst and communications strategist, and a former adviser to Jerusalem Mayor Nir Barkat, who has worked on campaigns in eight countries across three continents.