foehn wind Flashcards
What is the Foehn Wind?
Strong, dry, warm wind which occasionally develops on the Lee side of mountain ranges.
How do clouds form below the top of mountains regarding Foehn winds?
If the air rising up a mountain range has a high dewpoint temperature, the resultant cooling of the dry adiabatic lapse rate (DALR) may be sufficient for cloud to form below the top of the mountain.
When does cooling occur when Foehn wind air continues to rise inside the cloud? What will this result in?
- ONLY at the saturared adiabatic lapse rate (SALR).
- Precipitation will remove the excess moisture.
What happens to the weather when the Foehn wind air descends on the leeward side of mountains?
What does it result in?
- Warms at the DALR.
- Results in a warm, dry wind.
What is the cloud like on the ‘windward’ side as a result of Foehn wind?
Thicker and more widespread.
What are the weather conditions like on the windward side of mountains due to Foehn wind if condensation exists?
Cloud, rain and poor visibility can exit.
What causes freezing level to be lower on the windward side regarding Foehn wind?
What can this lead to?
- As ascending air cools at the appropriate adiabatic lapse rate, the freezing level will be lower on the windward side.
- Airframe icing and carb icing.
Where can severe turbulence be found regarding Foehn wind and what are the factors relating to this?
- Lee side.
- Factors include strength of wind and distance from hill range.
Where can the Foehn wind effect be found in NZ?
The Northwester wind in Canterbury, but can also occur in the North Island
