PJM’s First-Ever Meteorologist on the Job

Weather plays a vital role at PJM, specifically in determining load forecasts. When the air temperature changes, consumers’ electricity use changes, generating units operate differently, and, ultimately, transmission lines need to carry more electricity. In order to schedule enough generation resources, PJM needs precise weather forecasts so that electricity use can be predicted more accurately.

Why PJM now needs a meteorologist

Historically, PJM relied on automated forecasting programs to predict weather patterns based on seasonal norms. When extreme weather conditions such as Hurricane Irene occurred, the automated systems were no longer sufficient to provide consistent accuracy for load forecasts. The load forecasting error margin began exceeding the standard of three percent.

PJM researched other utility and member companies and found that hiring an operational meteorologist would be prudent. That’s when PJM hired Elizabeth Ellis, meteorologist – Dispatch, to fill the role. Ellis graduated from The Pennsylvania State University with a Bachelor of Science degree in meteorology and energy, business and finance.

“I always liked doing things a little differently than everyone else,” said Ellis on

why she’s working for a power grid rather than a television network. “When I started as a student in meteorology, I already knew I didn’t want to be a TV forecaster, because that’s what most of my peers wanted to do with their degrees. I love taking my knowledge of weather forecasting and applying it to something completely different, like load forecasting. And with my background in energy and economics, this is the perfect place for me.”

The role of a power grid meteorologist


Ellis provides Dispatch and senior management with current and future weather conditions, evaluation of the control room tools and determining which weather programs are the most effective for tracking weather changes.

Since hiring a meteorologist, PJM’s load forecast accuracy has consistently improved. In addition, Ellis suggested implementing several dedicated displays in the control room for tracking weather so that a visible display will always show weather radar and satellite data. The current displays are handled by the master coordinator as one of the many tools used in shift responsibilities.

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