When can we expect North foehn?
The graph shows the predicted atmospheric pressure difference in hectopascal [hPa] between Bolzano and Innsbruck. The pressure difference indicates the flow over the Alps.
For negative values, that means the pressure in Bolzano is lower than in Innsbruck, North foehn comes up in South Tyrol. The intensity of foehn wind increases with larger pressure difference.
Empirically we need at least a pressure difference of 3 hPa for the breakthrough of foehn winds in the northern valleys like the Vinschgau and Wipptal and at least 6 hPa for the breakthrough in the southern region like Bolzano.
In the contrary case (higher pressure in Bolzano) we have South foehn in the northern side of the Alps. At the same time often blows South wind in the valleys of South Tyrol.
The foehn chart is updated twice daily: 10:00 and 22:00.