Extreme Weather is the “New Norm”

The summer of extremes continues. July was the hottest month ever recorded. The high-impact weather is continuing through August.

“This is the new normal and does not come as a surprise,” said Alvaro Silva, a climate expert with WMO. “The frequency and intensity of many extremes, such as heatwaves and heavy precipitation, have increased in recent decades. There is high confidence that human induced climate change from greenhouse emissions, is the main driver,” he told a regular media briefing in Geneva.

Moderate and severe heat warnings for the third week of August have been issued by several national meteorological and hydrological services in Europe, including from France, Switzerland, Germany, Poland, Croatia, Italy, Greece, Hungary, Austria, Lithuania.

WMO stresses the need to follow authoritative warnings from national meteorological and hydrological services to stay safe.

During the weekend of 19–20 August, maximum temperatures may reach up to 40°C in parts of southern France, according to Meteo-France. It said it would be the most intense heatwave of the summer of 2023. This situation is due to a strong high pressure and subtropical warm air from North Africa.

Meteo-Suisse has issued level 3 amber alerts for most of the country, with maximum daytime temperatures between 33 and 35 °C and high night-time temperatures.

Morocco set a new national temperature record of 50.4°C in Agadir on 11 August, as temperatures crossed 50°C for the first time. Turkey reported a new national temperature record of 49.5°C on 15 August, beating the previous record of 49.1°C set in July 2021. Many parts of the Middle East also saw temperatures of above 50°C.

Spain, including Canary Islands, and Portugal also experienced extreme heat, fueling an extremely severe fire risk. As of 17 August, the Tenerife wildfire continued out of control, with more than 2600 ha burnt area and people evacuated in some sites. Dry conditions, maximum temperatures above 30°C, night temperatures above 20°C, peak wind gusts above 50 km/h were observed on 16 and 17 in some AEMET weather stations of Tenerife.

Japan has also suffered a prolonged heatwave, with many station records broken, according to the Japanese Meteorological Agency, which issued concurrent warnings for torrential rain and typhoon-related floods.

North America

Canada’s record-breaking wildfire season continues. More than 600 wildfires were out of control in Canada as of 17 August. In total there are more than 1 000 active firest, including 265 in the Northwestern Territories near the Arctic Circle. Authorities issued an evacuation order for the town of Yellowknife.

Environment and Climate Change Canada issued heat warnings in western Canada and widespread poor air quality warnings. Some daily temperature records were observed for example in Lytton, a new August temperature record of 42.2°C on 15 August 2023. (Old record of 40.6°C set in 1967 and records in this area have been kept since 1921.)

In the United States, the US National Weather Service says intense heat will build middle in the Plains this Friday, and continue to expand this weekend and early next week to include much of the Central and Southeast U.S. with maximum temperature forecasted to be above 100°F (38°C) in many parts and numerous daily temperature records expected.

Hurricane Hilary

Hurricane Hilary intensified to a major Category 4 hurricane on 18 August, according to the US National Hurricane Center, which is WMO’s Specialized Meteorological Center.

Maximum sustained winds increased on 18 August to near 140 mph (220 km/h),with higher gusts. Rapid intensification is expected to continue before the system begins to weaken.

On the forecast track, the center of Hilary will approach the Baja California peninsula in Mexico over the weekend of 19–20 August.

Hurricane-force winds extend outward up to 60 miles (95 km) from the center and tropical-storm-force winds extend outward up to 290 miles (465 km).

Hilary is expected to produce rainfall amounts of 3 to 6 inches (152 mm), with isolated maximum amounts up to 10 inches (254 mm), across portions of the Baja California Peninsula through Sunday night. Flash flooding, locally significant, will be possible. Rainfall amounts of 2 to 4 inches, with isolated amounts in excess of 8 inches, will be possible across portions of southern California and southern Nevada.

Courtesy of World Meteorological Organization (WMO).