It’s hurricane season in the North Atlantic and forecasters in the National Hurricane Center (NHC) in Miami are on high alert 24/7 shifts until November. Then they get six months of quiet weather when they get a chance to analyse the meteorology and forecasting skill of the previous season’s hurricanes.
During this quiet winter time they also do important outreach and training with the emergency services and citizens most affected by these monsters in Central and North America. The Hurricane names are chosen sequentially by the forecasters from a fixed list rotated through a six-year cycle.
The World Meteorological Organisation (WMO) Hurricane Committee has oversight of this list and names such as Mitch and Andrew are retired and replaced. Naming goes back to the 1600s when sailors called these beasts after the saint on whose feast day they struck but nowadays we try to name it a week before it strikes.
While undoubtedly a child of our warming world, Ophelia was not the first storm of hurricane origin to reach Ireland
The RDS, as part of their science outreach and education remit, hosted along with Met Éireann, Dr Mike Brennan from the NHC at a public talk in April 2018. Apart from wanting to hear about his fascinating job as a hurricane forecaster and his undoubtable Irish roots, Mike was invited as he led the transatlantic briefings between the NHC, Met Éireann and the UK Met Office ahead of the arrival of Hurricane Ophelia to our shores.
Ophelia was a rare beast having meandered northwards towards western Europe from the Cape Verdes instead of the usual path of moving westwards towards the Caribbean and developing there in the warm 27 degrees plus waters. On October 16th, 2017 Ophelia having maintained Category 1 status only six hours from Kerry, thankfully — as forecast — transitioned into a mid-latitude storm as it spun out over our relatively cool seas of 16 degrees. While devastatingly there was some loss of life, modern forecasting methods led to sufficient preparation time and a red alert closed the country down for one day under the guidance of Seán Hogan and the National Directorate for Fire and Emergency Services.
However, while undoubtedly a child of our warming world, Ophelia was not the first storm of hurricane origin to reach Ireland. The most similar track was by so-called Hurricane Debbie in 1961 which raced up from the Canaries along the west coast of Ireland and caused significant destruction from Kerry up to Sligo and Donegal and then over Northern Ireland. Unlike Ophelia, Debbie was not forecast in this pre-satellite and pre-computer era and there were tragically 28 fatalities. Damage included the entire glasshouse industry in Donegal being wiped out.
While summer is the busy time for the NHC in Miami, traditionally it is meant to be a fairly quiet time for weather forecasters in Europe
More recently in August, 1986, ex-Hurricane Charley dumped a record breaking 280mm of rain across Dublin and Wicklow resulting in widespread flooding including the controversially so-called “trendy cottages” in Dublin 4. Mount Usher Gardens in Wicklow were destroyed and tragically 11 people lost their lives. While atmospheric modelling was developing in 1987 it was still in its infancy and the severity of the rainfall was not forecast nor indeed were any of the impacts.
Met Éireann have done a reanalysis of this event and will be running our high-resolution weather model designed specifically for Ireland to reproduce its circumstances and to gauge its predictability. We also are moving strongly towards Impact-based warnings rather than by criteria alone.
Hurricane Charley itself had spent its fury over in the United States but it was not finished as the “left-over” low pressure system engaged with the North Atlantic jet stream. The low tracked steadily across the Atlantic and 10 days after it had struck Georgia and South Carolina, the tropical rainfall here alleviated drought conditions but also producing damaging winds of 130km/h.
It tracked along the south coast of Ireland on August 25th and then took a sharp left at Wexford and slowly moved northwards over the Irish Sea dumping its rain down relentlessly over a 24-hour period over the East coast. There was orographic enhancement of this moisture laden tropical weather system over the Wicklow Mountains with onshore northeast winds on the northern flank of the low. Similar enough to the so-called nor’easters which affect the east coast of the US but without the wind thankfully.
Events like these are outliers to our usual rather benign, temperate weather but the warming atmosphere is producing more frequent and stronger outliers worldwide as witnessed with this summer’s European heatwaves. The physics of the atmosphere explaining this has long been understood and demonstrated in the Royal Institution by our own John Tyndall, born in Leighlinbridge, Co Carlow, in 1820. He identified that heat trapping gases such as water vapour and carbon dioxide are necessary for life on Earth otherwise “we would be gripped in frost”, but too much and we would fry.
While summer is the busy time for the NHC in Miami, traditionally it is meant to be a fairly quiet time for weather forecasters in Europe when we get a chance to do some study and training and make preparations for the potential severe weather approaching in winter. We also get to pick storm names for the coming season which starts on September 1st.
In 2015 Met Éireann and the UK Met Office trialled a storm naming scheme which instantly took off as an effective method of communicating weather warnings, as well as impact risks and dangers. RTÉ’s Teresa Mannion valiantly played her part in this ahead of Storm Desmond. Who will ever forget, “Don’t make unnecessary journeys.”
Now all national met services (NMSs) in Europe have agreed to name storms. The rules are simple. The NMS which predicts orange or red level warnings/impacts from a low pressure system names it a few days ahead to highlight the potential severe impacts. It doesn’t have to be for wind. It can be for rain or snow too. For example, the Dutch KNMI named storm Darcy ahead of expected blizzards in March 2021.
However for many European Met Services the record-breaking summer heat requires Red level warnings matching in impacts any winter storms. In fact heatwaves and the attendant wildfires and droughts cause much more severe and fatal impacts on society than storms.
The early onset heatwaves in June and unprecedented 40+ degree heat and other worldwide extreme severe weather such as floods, droughts and storms have left scientists facing their worst fears. This is climate change in action; its effects have started earlier than predicted and its just the beginning with the Arctic and Greenland moving towards meltdown ... literally. John Tyndall’s greenhouse gases are demonstrating their heat-trapping properties in a very real and a very frightening way.
As a small Island nation we will be saved to some extent from the most extreme heat by the cooling effect of the Atlantic Ocean and it’s this same ocean that could help solve our energy crisis through wind and wave power — but it could also drown out Galway, Cork and Dublin if things progress as at present.
Evelyn Cusack is Head of Forecasting Division at Met Éireann