Weather Conditions that Depend on Seasons
Orographic Lifting
Moist air is always dangerous in flying. When it is lifted it forms cloud bases or worse depending on the season.
Flat-landers see this in the Winter. Keep in mind air loses its moisture when temperatures a low. Using the Adiabatic Lapse Rate of 4.5 degrees F the air will cool each 1,000 feet the air is lifted. There is a relationship between unsaturated air and its dew point. When the air temperature reaches its dew point condensation occurs and clouds begin to form. Now the situation changes, will the dryer air continue to rise to a level where freezing of the water molecules begins. Energy release begins and rapid buildups of clouds starts. Thunderstorms is the ultimate result of lifting air with moisture present.
In mountains the amount of air may contain less moisture than at sea level and the cloud bases form below the peaks. This cuts visibility and, if you fly into them you may meet what ever the cloud is hiding.
In the summer time the air, at high elevations, can contain more moisture. As the lifting of the air, by bumping into mountain slopes, occurs the air not only reaches the point where condensation takes place but continues to rise until the freezing point of water is reached. When a change of state from liquid to a solid (ice) heat is given off. This increase in heat pushes the cloud development to a level where a thunderstorm forms. Weather, weather and more weather. IFR pilots are very cautious about weather. It is an excellent safety lesson.
Mountain valleys are places where an inversion can happen. Cold dense air tumbles underneath warmer air that contains more moisture. Cloud formation begins at night to form under the warm air and fog forms.
Your departure and arrival should coincide with a time when the fog layer heats up and dissipates with sunrise. If the weather calls for a cloudy day it will take longer for the fog to clear.
Moist air is always dangerous in flying. When it is lifted it forms cloud bases or worse depending on the season.
If you into weather (and you should be) the Adiabatic Lapse Rate and the Dew Point is a rough way to predict cloud bases for decision making in flight plans.
In mountains the amount of air may contain less moisture than at sea level and the cloud bases form below the peaks. This cuts visibility and, if you fly into them you may meet what ever the cloud is hiding.
In the summer time the air, at high elevations, can contain more moisture. As the lifting of the air, by bumping into mountain slopes, occurs the air not only reaches the point where condensation takes place but continues to rise until the freezing point of water is reached. When a change of state from liquid to a solid (ice) heat is given off. This increase in heat pushes the cloud development to a level where a thunderstorm forms. Weather, weather and more weather. IFR pilots are very cautious about weather. It is an excellent safety lesson.
Temperature inversions
Mountain valleys are places where an inversion can happen. Cold dense air tumbles underneath warmer air that contains more moisture. Cloud formation begins at night to form under the warm air and fog forms.
Your departure and arrival should coincide with a time when the fog layer heats up and dissipates with sunrise. If the weather calls for a cloudy day it will take longer for the fog to clear.
