May 18, 1980. It was a mild sunny Sunday morning. People were walking their dogs, some enjoying their morning coffee, and others still rising from their weekend slumber.

I was a young forecaster with the National Weather Service Seattle Forecast Office working the aviation forecast desk. Back then, we were a state forecast office. So I was responsible for forecasts across the state at air terminals like Seattle-Tacoma International Airport (SEA), Boeing Field, Spokane, Yakima, Wenatchee, Paine Field – Everett, and Bellingham as well as air route forecasts between many of these locations.

At my desk in the far left corner was a red phone. The phone was a hotline between the FAA flight service station at Boeing Field and us. I was told it had never rung. Yet shortly after 8:30 a.m. that morning, that red phone rang.

I picked it up – ‘Seattle Weather’! The flight service staffer said he had a pilot on the radio that needed help and he was going to patch me through. I was suddenly talking with that pilot.

The pilot was flying a sight-seeing tour group of five out of Chehalis in a twin-engine Cessna around Mount St Helens. Right away, I could tell something BIG had happened. The pilot told me he was on the south side of the mountain when it blew. The force twisted his plane vertically with the wings pointed up and down, he was being pelted with rocks, and it felt like they got hit by the heat of a monstrous pizza oven.

He had already spun the aircraft south toward Portland and regained control. He wanted to know where the ash plume was going and how to get back to Chehalis. In the meantime, I could hear the five frantic passengers in the background. Let’s just say their language was R-rated.

The latest plume trajectory forecast based on the winds aloft was released earlier in the morning to support all the groups involved in the volcano’s preparedness. Those groups included the U.S. Forest Service, the U.S. Geological Survey, the Federal Aviation Administration (FAA), emergency management organizations including Cowlitz and Skamania Counties, the state of Washington, and more. Since the volcano’s tummy began rumbling in March, these groups worked together to prepare plans to respond in case of an eruption. Those plans were fully executed that morning.

I informed the pilot that the plume was heading east-northeast and that he could turn toward Kelso and follow Interstate 5 north to Chehalis with no impact. He thanked me for the guidance, and I hung up the red phone.

My lead forecaster Paul looked at me with a knowing gaze of what that red phone call conversation involved. I assured him, it was the anticipated eruption of Mount St. Helens.

The NWS response role involved several pieces. First, Paul issued a flash flood warning and the Emergency Broadcast System (EBS back then) was activated. I had several tasks to do. Initially, I contacted the Air Route Traffic Control Center in Auburn to inform them of the eruption and where the plume was headed. Their job was to shut down the airspace in the path of the ash plume and divert all aircraft away from any ash. The eruption threw ash as high as 80,000 feet into the atmosphere.

I next updated all the Eastern Washington-coded air terminal forecasts. But there was a problem; there was no code for volcanic ash. The International Civil Aviation Organization or ICAO had not established an aviation forecast code for volcanic ash. I gave Paul a few options and we chose ‘dust’. That element was the closest available to ash. Since then, the ICAO has created a volcanic ash code.

After that, I updated all the air route forecasts that involved the volcanic ash plume. In all, that hour on a mild sunny Sunday morning was one that blew by fast. Most have big highlights in their career and for me; this was my first – quite memorable.

57 people around the volcano perished that morning. A lahar roared down the Toutle River, and tons of debris settled into the river, Cowlitz River, and dumped into the Columbia River. Ash was transported around the world and in Eastern Washington; skies darkened so that streetlights turned on, and up to five inches of ash piled up. It was a historic day.