High-pressure ridge keeps Switzerland’s heatwave in place

Switzerland’s heatwave is expected to continue, with temperatures above 30 degrees forecast again this week, Swiss broadcaster SRF reports. The mostly sunny and hot weather has persisted for weeks.

According to Jürg Zogg, a meteorologist with SRF Meteo, the country has been under largely constant high-pressure conditions. A high-pressure ridge in the upper layers of the atmosphere is reinforcing the stable weather and steering low-pressure systems and other disturbances in a wide arc around Switzerland.

Only occasional weaker zones have allowed isolated showers or thunderstorms to reach the country. Once such a blocking pattern forms, it tends to remain stable, with successive high-pressure ridges moving in.

The pattern would have to shift for the weather to change. If the high-pressure system moved away, low-pressure systems could advance towards Switzerland from the west or northwest, bringing cooler air and a greater likelihood of rain.

SRF Meteo sees no clear sign of that happening this week. The mostly sunny and hot summer weather is expected to continue through Saturday. Early forecasts suggest the high-pressure system could move east on Sunday or possibly Monday, potentially opening the way for disturbances from the northwest.

That would not necessarily end the heat immediately. The chance of rain could rise somewhat on Sunday, Monday or Tuesday, but this remains an initial trend. Another high-pressure system could soon arrive and bring back the hot weather.