Aviation meteorologists plan for and around difficult conditions, crafting weather forecasts used to determine the nuances of flights, from altitude to optimal routes. They play an essential role in ensuring travelers get to their destinations safely and efficiently.

Several major domestic carriers, including Delta Air Lines, have in-house meteorologists who monitor global weather 24 hours a day. Delta has 28 meteorologists on staff — the largest team of any airline, it declares — who sit in the carrier’s Operations and Customer Center, alongside flight dispatchers, customer service agents and hundreds of other staffers, at its headquarters in Atlanta.

In this cavernous and screen-filled room, Warren Weston, Delta’s lead meteorologist, recently spoke about the importance of data, the difference between surface weather and upper-air hazards, and how even one degree of temperature can change a flight plan. The conversation has been edited and condensed for clarity.