Airlines can’t control the weather. They can only do the next best thing, which is to predict upcoming hazards as accurately as possible, as soon as possible, and plan ahead for route disruptions. To do that, they need a team of meteorologists tracking conditions in the sky and on the ground. Delta Air Lines gave PopSci a peek into the inner workings of their weather team. Here’s what we found out. 

“There’s always weather. Every summer, we’re always ready for thunderstorms, we’re always ready for hot temperatures across the desert southwest,” says Warren Weston, lead meteorologist at Delta. Summer brings its unique set of challenges. For this summer in particular, Weston says they observed a fairly persistent high pressure set up across the desert southwest. 

“When we saw the hot temperatures, we started producing a daily forecast for Las Vegas, Phoenix, and Salt Lake City, that was available not only to our decision-makers here within our operation center, but it was also visible to the station managers in the field,” he adds. “And they could look at each day to see what the temperature was each hour, so they would know what hours of the day to expect the highest impact, and we were able to give them this higher resolution data for them to make decisions.” 

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Climate change is adding another set of challenges for meteorologists. But weather is an incredibly data-driven field, and Weston hopes that with the learnings they gather each summer, they’ll be able to predict hazardous events in a better and more timely manner. 

Here’s a detailed look at the breakdown of the meteorology team’s job. Delta boasts that it has 23 meteorologists on staff, which is more than any other airline. 

Every day, this team provides weather briefings to the operations operators at airports, and monitors ongoing conditions. They source a great deal of publicly available data from the National Weather Service and the National Oceanic and Atmospheric Administration. The team also uses in-house data for their predictions. For instance, if a plane is flying from point A to point B, and they start receiving turbulence, they can make a pilot report. That report is visible inside of Delta’s operation center, and the team can use that information to refine their turbulence forecast. 

Airline meterologists are the sole weather providers for Delta Air Lines. But every day they collaborate with government meteorologists and other airline meteorologists on highlighted areas of concern, like if a line of thunderstorms is traveling across a specific area in the US. They also collaborate with the air traffic control system command center in Washington DC to give them an idea of what Delta is thinking in terms of tailoring their routes based on the forecasts.

The meteorologists are split into two groups: The “surface desk” and the “upper air desk.”

The surface desk meteorologists look at Delta’s hub airports like Atlanta and New York City closely and puts out detailed hourly forecasts, primarily for the next 30 hours. “On those desks we’re looking for things like thunderstorms, is there going to be low clouds causing fog, or anything that could prevent us from getting into that airport when we attempt to land,” says Weston.

The “upper air desk” looks at high-level turbulence and other conditions such as space weather like solar flares, concentrations of ozone, and even volcanic ash, which can damage an airplane’s engines.

“On the upper air side, most of our forecasts are happening well before the flight is planned. If you think about a 10-hour flight from the US to Europe, you need a forecast that’s valid for the next 10 or 15 hours, not just right now,” Weston says. “We’re looking at turbulence, thunderstorms, and working with our flight planners to find the most efficient route with the least amount of turbulence.”

For example, if there was a snowstorm forecast for New York City, they’ll start issuing updates a few days before the storm gets there to other parts of the operation like the station manager looking at staffing levels. Extra hands may be needed if planes need de-icing. If it isn’t planned for, that can all cause delays. 

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If a hurricane or severe storm is brewing, the meteorology team has to issue a specific forecast showing when the main impacts will be. “Most of the times in a hurricane you’ll get winds high enough that it’s over the threshold that an airplane is able to land or take off in. So it’s our job to narrow down that time frame to say between this period and this period, conditions are going to be inoperable,” Weston explains. “But, as we get outside of this time period, the winds will come down and we should be able to gradually start operating, and restore operation to a certain region.” 

The team monitors air quality conditions too, not just for seeing whether planes can fly, but for ensuring that the ground crew is staying safe as well. In that respect, wildfire smoke has become an item of note to look out for. “Smoke is very unique because of course we don’t predict the formation of smoke, because that’s predicting a forest fire which we are not in the business of doing,” Weston says. “But our concern with the fire is that it results in mostly air quality issues. If the air quality because of the smoke reaches a certain threshold, then there’s processes in place, like having [the ground crew members] mask, or having them work outside only for a certain amount of time.”