We all become a bit pre-occupied with the weather at this time of year, whether it's because family members are flying back from holidays at home or we ourselves are making the most of the last few days of the festive season.
Aviation weather forecaster Michelle Dillon is one of a team of forecasters who work 24/7 at Met Éireann, offering regular forecasts to the airports, aeroplanes and search-and-rescue helicopters flying in Irish air space.
“We send standard forecasts four times a day to airports in Shannon, Dublin, Knock and Cork. These include wind speed, wind direction, visibility, amount and height or cloud cover. We also issue four- to five-day planning forecasts, highlighting any hazards such as snow and ice on the runway or aircraft, freezing temperatures, fog, heavy rain or cross winds. This allows the airports to plan take-offs and landings accordingly.”
Fog in particular is a huge problem for airports, which rely on accurate forecasting to adjust landing and take-off times.
‘Needs to be accurate’
“If we issue low visibility, it takes a while for the airport procedures to be put in place. It’s short-term, specific forecasting which needs to be accurate,” says Dillon.
If there is a search and rescue mission, the forecast briefings to these helicopters are prioritised. The aviation forecasters also offer verbal en-route weather briefings to small aircraft at a premium rate.
The biggest difficulty in winter is the changing weather systems. “There might be a rapidly deepening Atlantic system which will change the timing of weather coming in. The decisions we make have a big impact on our customers. If we issue fog or snow warnings, they call in teams of workers.”
‘Atmosphere is chaotic’
Dillon says there is no reliable forecast beyond 10 days. “The atmosphere is chaotic. Even shorter-term forecasting is based on combining a number of forecasts and getting the best estimates using [mathematical] models.” Our geographical position on the edge of the Atlantic means we can’t rely on ground-level forecasting from surrounding countries. “We do get forecasts from aircraft and ships and we have satellites but the Atlantic Ocean means we don’t have ground forecasts to the west.”
The aviation forecasters work 12-hour shifts in the meteorological station in Glasnevin. Dillon studied mathematics and computer science at undergraduate level and then completed masters degrees in both mathematics and meteorology. She has worked at Met Éireann for eight years.
“Getting warnings out on time and monitoring changing weather systems is what I enjoy. It’s not an exact science. You can only give your best forecast. The satisfaction of getting it right is the best part of the job; making sure the skies are safe and airports can plan efficiently and cost-effectively.”
