AEROGRAPHER'S MATE 3 & 2 



(B) SHALLOW STATIONARY FRONT 



Figure 14-17. — Types of unstable stationary fronts. 



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PRESSURE AT FRONTS 



One of the important characteristics of all 

 fronts is that on both sides of a front the 

 pressure is higher than at the front. This is 

 true even though one of the air masses is 

 relatively warm and the other is relatively 

 cold. Fronts are associated with troughs of 



low pressure. (A trough is defined as an 

 elongated area of relatively low pressure.) A 

 trough may have U-shaped or V-shaped lo- 

 bars. 



Friction causes the air near the ground 

 to drift across the isobars toward lower 

 pressure. This causes a drift of air toward 

 the front from both sides. Since the air 



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