Some may recognize this, but a refresher is always a good thing:
The topic of thermals seems to come up occasionally and hope this post is helpful.
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Thermals should not be confused with Wind.
Thermals are driven mostly by the heating/cooling of the earth surface
Thermals are very gentle movements of the air, sometimes almost imperceptible.
Cold air sinking below the rising thermal causes a downdraft.
That\'s why you can feel thermals in your face in one spot, then feel it on your neck in another.
Typically the thermals move DOWNSLOPE in the mornings until the air heats. When the air heats up, it mixes.
After the air heats up and stabilizes, the thermals will be UPSLOPE during the day.
Later in the day, as the air starts to cool, the thermals will mix again and then just before dark, they will be predominately DOWNSLOPE again
Thermals are weather dependent. You wont have any consistent thermals if a weather front is moving thru.
Slope direction definitely has an impact. The sun or prevailing wind will warm one side or mix it before the other.
Here\'s some more info regarding thermals...
Downslope wind—
1. A wind directed down a slope, often used to describe winds produced by processes larger in scale than the slope. Because this flow produces subsidence, downslope winds experience warming, drying, increasing stability, and clearing if clouds are present.
2. Flow directed down a mountain slope and driven by cooling at the earth\'s surface: a component of the mountain–valley or mountain–plains wind systems; same as katabatic wind.
The many synonyms for downslope flow are sometimes used interchangeably, and this gives rise to ambiguity and confusion. Downslope can be used generically to denote any wind flow blowing down a slope, or it is used specifically for katabatic flows on any scale, such as the nocturnal slope-wind component of mountain–valley wind systems or mountain–plains wind systems.
The topic of thermals seems to come up occasionally and hope this post is helpful.
********
Thermals should not be confused with Wind.
Thermals are driven mostly by the heating/cooling of the earth surface
Thermals are very gentle movements of the air, sometimes almost imperceptible.
Cold air sinking below the rising thermal causes a downdraft.
That\'s why you can feel thermals in your face in one spot, then feel it on your neck in another.
Typically the thermals move DOWNSLOPE in the mornings until the air heats. When the air heats up, it mixes.
After the air heats up and stabilizes, the thermals will be UPSLOPE during the day.
Later in the day, as the air starts to cool, the thermals will mix again and then just before dark, they will be predominately DOWNSLOPE again
Thermals are weather dependent. You wont have any consistent thermals if a weather front is moving thru.
Slope direction definitely has an impact. The sun or prevailing wind will warm one side or mix it before the other.
Here\'s some more info regarding thermals...
Downslope wind—
1. A wind directed down a slope, often used to describe winds produced by processes larger in scale than the slope. Because this flow produces subsidence, downslope winds experience warming, drying, increasing stability, and clearing if clouds are present.
2. Flow directed down a mountain slope and driven by cooling at the earth\'s surface: a component of the mountain–valley or mountain–plains wind systems; same as katabatic wind.
The many synonyms for downslope flow are sometimes used interchangeably, and this gives rise to ambiguity and confusion. Downslope can be used generically to denote any wind flow blowing down a slope, or it is used specifically for katabatic flows on any scale, such as the nocturnal slope-wind component of mountain–valley wind systems or mountain–plains wind systems.
