Heat wave on the way?
If you follow social media or read the tabloids, you won’t have missed the headlines of the last few days that a tropical heat wave is on its way to the UK next week.
So, it’s true, and how hot will it be?
What are the rumors?
Some publications report a UK maximum of 40ºC around 16 July.
This is because one of our supercomputer models on Saturday 2 July, for the first time, raised a scenario where some parts of the UK could reach a high of 41ºC next week.
If that happened, it is unlikely to happen, it would be unprecedented.
The fact that a computer model has even suggested a temperature above 40ºC in the UK is a first and worrying sign that climate change predictions are becoming a reality.
Most popular forecast so far for the UK: GFS computer model forecast for July 16 as of Saturday, July 2, 2022 Credit: Data: GFS. Website: www.wetterzentrale.de
What is computer modeling?
To help predict the weather in advance, meteorologists use mathematical predictions made by supercomputers, called computer modeling.
There are several around the world, each using historical data and observations of the Earth to give a possible scenario of the weather ahead, based on probability.
In the UK we have our Met Office supercomputer. This requires about half a million observations a day. When there is no data, the computer will fill in the blanks.
The closer we get to the forecast day (or event), the more accurate the model will be, because it has more information.
Sometimes the models are different. Sometimes everyone agrees.
Currently, most models highlight a “warming trend” from the end of this week and continuing until next week. But the 40ºC scenario, thankfully, seems unlikely.
Most likely scenario (to date) – GFS computer model forecast for July 16 as of Monday, July 4. Credit: Data: GFS. Website: www.wetterzentrale.de
What is the reality?
Remember that the model’s forecast was for almost two weeks. Today Monday, July 4, after only 48 hours, the temperature forecast for the 16 has already dropped more than 10 degrees.
But a 10-degree drop could still bring part of the UK to about 30ºC of heat by the end of next week.
This is higher than the heat wave threshold of the UK Meteorological Office and above the July average.
Heatwave Threshold for the UK (3 consecutive days or more) Credit: Met Office
So at this stage, we’re looking at things getting warmer by the end of this week, with the heat wave criteria possibly being met next week.
It’s July. Heat waves are becoming more frequent. 30ºC is not as unusual as it was a decade ago.
And as we get closer, day by day, computer models will adjust their predictions using the latest information.
Stay tuned for the forecast, not the gossip!