<p>An answer I got on Reddit which seems to make sense is that fronts are usually accompanied by a pressure change which locally reinforces the &quot;normal&quot; <a href="https://en.wikipedia.org/wiki/Geostrophic_wind" rel="nofollow noreferrer">geostrophic wind</a> which changes the wind direction.</p>
<p>If anyone has a more in depth answer I'd love to hear it.</p>

CC BY-SA 4.0
2020-12-14T07:53:49.067Z
2020-12-14T07:53:49.067Z
Borgh
<p>Plenty of answers answer the question <em>that</em> it happens but I can't find a good answer as to <em>why</em> the wind shifts during the passing of a front.
For an extreme example see:
<a href="https://i.sstatic.net/gE2hc.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/gE2hc.png" alt="a graph of an abrubt wind shift" /></a></p>
<p>(in Dutch, x is hours and y is wind direction in degrees)<br />
Where a passing cold front moved the wind directon from south to northwest.</p>
<p>The other question provides a very broad answer as to why wind changes <em>in general</em> and the answers there are applicable <em>in general</em>. My question is about the specific circumstances of a thermal front and what causes the change in the balance of forces to suddenly allow or force the direction of the wind to change direction.</p>

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2020-12-15T14:55:34.500Z
@gansub sadly no, that answer is about the regular wind inside a system without fronts passing.
Borgh
CC BY-SA 4.0
2020-12-15T17:41:22.563Z
So yeah, what is that balance condition? It seems that a front either provides or releases some form of friction to, quite suddenly, change the balance of forces that makes the wind blow in a certain direction. Is it just the boundary between two air masses that provides this resistance?
Borgh
CC BY-SA 4.0
2020-12-16T11:45:26.420Z
Mate if a wikipedia article answered my question I wouldn't be here. You seem to know the answer, please walk me through it.
Borgh
<meteorology><wind>
Why does wind direction change in a front?
Borgh
# Why does wind direction change in a front?

(Asked by: username_0 on 2020-12-13)

Plenty of answers answer the question *that* it happens but I can't find a good answer as to *why* the wind shifts during the passing of a front.
For an extreme example see:
[![a graph of an abrubt wind shift](https://i.sstatic.net/gE2hc.png)](https://i.sstatic.net/gE2hc.png)

(in Dutch, x is hours and y is wind direction in degrees)  
Where a passing cold front moved the wind directon from south to northwest.

The other question provides a very broad answer as to why wind changes *in general* and the answers there are applicable *in general*. My question is about the specific circumstances of a thermal front and what causes the change in the balance of forces to suddenly allow or force the direction of the wind to change direction.

**Tags:** meteorology, wind

> **Comments:**
> **username_0**: @gansub sadly no, that answer is about the regular wind inside a system without fronts passing.  
> **username_0**: So yeah, what is that balance condition? It seems that a front either provides or releases some form of friction to, quite suddenly, change the balance of forces that makes the wind blow in a certain direction. Is it just the boundary between two air masses that provides this resistance?  
> **username_0**: Mate if a wikipedia article answered my question I wouldn't be here. You seem to know the answer, please walk me through it.  

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## 1 answers

### Answer by username_0 on 2020-12-14. Score: 2

An answer I got on Reddit which seems to make sense is that fronts are usually accompanied by a pressure change which locally reinforces the "normal" [geostrophic wind](https://en.wikipedia.org/wiki/Geostrophic_wind) which changes the wind direction.

If anyone has a more in depth answer I'd love to hear it.


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