On Monday, March 9, strong storms affected parts of southern France, and several departments, including Hérault, Var and the Alpes-Maritimes, were placed under yellow alert for heavy rain.
Some of the heaviest rainfall totals came from a cell that passed over the Var department. Examples of high rainfall totals taken from some private weather stations come from the cities of Carqueiranne and Saint-Mandrier-sur-Mer, where 104.4 mm were recorded in seven and a half hours and 92.7 mm in three hours, respectively. However, as they are private weather stations, they may contain measurement errors.
The official Hyères weather station recorded 113.7 mm in 24 hours, which makes these values seem credible. This marks a new record for the station, surpassing the previous March daily record of 84.1 mm in 1988.
Furthermore, due to these heavy rains, the Gapeau River in Var overflowed. The river reached a height of 2.34 m, approaching the 2.66 m observed in the November 2011 floods, and as a result flooding continued over the following days.
The United States has experienced an active few days of severe convective storms, including heavy rain, tornadoes, and large hail. As a result, the state of Illinois may be on track to record a new hail size record. On Tuesday, a Kankakee City resident reported six-inch hail that, if verified, would set a new state record. The previous state record was 4.75 inches and was recorded in the village of Miniooka in June 2015. There have been other reports of hail exceeding this diameter, so a new record will likely be made official soon.
A persistent region of high pressure has brought record-breaking heat across South Africa’s Namakwa District and Western Cape, with many weather stations breaking their March temperature records. The strong anticyclone resulted in the formation of a “heat dome”, where the air descending below this high pressure zone is continuously compressed and heated throughout the days, resulting in very dry and hot conditions. Notable new temperature records for March include a reading of 42.1°C recorded in Cape Town, more than 2°C warmer than the previous record of 39.8°C set in March 2015.
