It's not unusual for weather patterns to impact air travel. However, something is happening this week that is quite out of the ordinary! A jet stream is causing a high number of flights to land at San Francisco International Airport (SFO) up to an hour early. It turns out there is actually an unusually calm jet stream over the United States at the moment.

Many travelers headed to San Francisco from the East Coast were surprised at the start of this week when they arrived at their destination between 45 minutes and one full hour ahead of schedule. This week's jet stream is having a very positive impact on SFO's on-time arrival numbers. The airport usually sees an on-time arrival rate of 75 percent. However, Sunday saw the rate of flights arriving early or on time jump to 90 percent. This has been good news for travelers heading to the West Coast from hubs like Atlanta and New York.

Travelers who are heading to San Francisco in the days and weeks to come shouldn't get too excited about the jet stream. What's happening this week is extremely rare. What's more, forecasters can't really say how long a calm jet stream will last or when another one can be expected to follow. Travelers who head from the East Coast to the West Coast have to deal with flying into what are usually very strong headwinds. The only thing to take away from this week's anomaly is that travelers should enjoy it while it lasts!

Scott Dylan is a contributing writer at GET.com and has been to (almost) every country in North, Central and South America with nothing more than a backpack, a laptop and the desire to explore. He speaks Spanish fluently and has logged enough time in planes, trains, rideshares, buses, taxis and rickshaws to know how to rack up rewards and points to get anywhere his heart desires for pennies on the dollar. Email: scott.dylan@get.com.