What Met Office weather warnings REALLY mean: The differences between the three-tier system as forecasting agency faces backlash over Storm Bert floods
Hours before the deadly Great Storm of 1987 devastated Britain, weatherman Michael Fish famously told viewers not to worry about a hurricane on the way.
Hours before the deadly Great Storm of 1987 devastated Britain, weatherman Michael Fish famously told viewers not to worry about a hurricane on the way.
But historys worst forecasting failure is also remembered for leading the Met Office to launch the National Severe Weather Warning Service (NSWWS) the following year.
The system still exists today and has come back into focus this week after the Met Office was accused in Parliament yesterday of incompetence that led to a clear underestimation of the impact of Storm Bert which caused widespread flooding.
While the Met Office has defended its forecasting after issuing 50 warnings last week, bosses said they were committed to learning the lessons from the storm.
And they will be under the microscope once again tonight after forecasters revealed Storm Conall will bring up to 2in (50mm) of rain to the South from 10pm.
It comes after experts raised fears back in February that Britons could become complacent and ignore Met Office weather warnings due to a near-record number of named storms in that year amid increasing numbers of yellow and amber alerts.
The warnings system has evolved into todays three-tier warnings service to forecast the expected impact of severe weather and the likelihood of this occurring.
Yellow, amber or red warnings are issued for a range of impact levels and likelihoods for rain, thunderstorms, wind, snow, lightning, ice, extreme heat and fog.
The alerts can have broad meanings given that a forecast with high impact but that is unlikely to happen will perhaps only get a yellow warning; and vice versa.
Two people pour water out of the front garden of a flooded property in Pontypridd on Sunday
Billing Aquadrome in Northamptonshire was badly flooded after heavy rain over the weekend
The River Avon burst its banks and flooded nearby properties in Bradford-on-Avon yesterday
A car drives through floodwater as water levels rise on the River Ouse in York yesterday
Yellow warnings are the most common and normally mean people can continue with their daily routine but should be aware that some travel disruption could be caused.
They can also be issued when the conditions could bring far more severe impacts to most people, but the certainty of these impacts happening is much lower.
Amber warnings mean an increased possibility of severe weather with a higher chance of travel delays, road closures, power cuts, and risk to life and property.
The top tier of red means dangerous weather is expected and people should take action to keep themselves safe, with substantial disruption and damage expected.
Factors considered by forecasters include the time of day, week and year, the location, underlying wet or dry ground conditions and any local events taking place.
While the Met Office can warn of flooding within a weather warning, flood alerts and warnings themselves are issued by flood agencies such as the Environment Agency for England or Natural Resources Wales.
The current system has its roots in the development of better forecasting following the 1987 Great Storm on the night of October 15 which saw Britain hit by winds of up to 115mph - including 94mph in London.
Some 18 people were killed, 15million trees were felled and billions of pounds worth of damage was caused in what was the worst storm for almost 300 years.
Forecasters had been predicting severe weather for days before the storm - but thought it would pass to the South of England and failed to predict its severity, which later provoked ridicule.
Fish famously said on the BBC lunchtime news before the storm struck: ...earlier on today apparently, a woman rang the BBC and said shed heard there was a hurricane on the way. Well, if you are watching, dont worry, there isnt…..
The incident achieved such notoriety that it featured in the opening ceremony of the London 2012 Olympic Games. Fish, now 80, later revealed that the woman caller never existed and that it is one of a number of myths surrounding the incident.
But the devastation and lack of proper forecast of the worst storm since 1703 resulted in major investment and improvement in the science, technology and communication of forecasting, including the NSWWS starting in 1988.
The Met Office wanted to provide a coordinated way of delivering warnings to government, industry, emergency responders and the public – and help people prepare for and take action to avoid the impacts of severe weather.
In the years before widespread internet access, the warnings were faxed and emailed to emergency responders and media organisations.
Yellow, amber or red warnings are now issued for a range of impact levels and likelihoods
The Met Office issues a range of information to accompany weather warnings, as shown above
The Met Office now issues weather warning maps on social media, such as this one for tonight
The scheme initially worked as a threshold-based system, delivering warnings when wind or rain of sufficient intensity was predicted.
But as the service evolved, the Met Office switched to an impact-based service in 2011 that took account of timing and environmental conditions to help people get a better idea of how conditions would affect them.
The delivery of the alerts also changed as more people began to check weather forecasts and warnings online, including through apps and social media.
In addition to the NSWWS, the Met Office launched the storm names project in 2015, giving titles to medium and high impact storms.
The aim of the scheme brought in alongside the Irish meteorological service Met Éireann was to further improve the communication of incoming severe weather.
The service has also now been extended to a seven-day lead-time rather than five, with the aim of giving the public more advance notice of bad weather.
Damage caused by the 1987 Great Storm which saw Britain hit by winds of up to 115mph
Some 18 people were killed and 15million trees were felled by the Great Storm of 1987
Michael Fish famously told BBC viewers not to worry about a hurricane on the way in 1987
Today, the Met Office insisted it will learn lessons from Storm Bert after criticism over its incompetence that led to a clear underestimation of the devastating impact.
Hundreds of homes were left underwater and roads turned into rivers after the UK was hit by up to seven inches of rain, heavy snow and 82mph winds at the weekend.
Torrential downpours caused widespread flooding with nearly 300 warnings or alerts still in place across Britain this morning as major rail disruption continued.
The Met Office was accused of letting down the public with Labour MP for Cardiff West, Alex Barros-Curtis, saying warnings should have been amber or red.
But Met Office services director Simon Brown insisted observed rainfall totals were broadly in line with the forecast and the severe weather warnings issued in advance.
He said 50 weather warnings were issued last week, but added: Im committed to learning the lessons from Storm Bert to support even greater preparedness.
