低压槽是从低压中心延伸出来的狭长区域，经常与锋伴随出现。

与锋面不同，槽在天气图上没有通用的符号。在美国，槽是用虚线表示，如果槽线没有标明，也可以通过从低压中心延伸出来的等压线或等高线来判断。还有一些国家和地区，槽在天气图上用虚线表示。在香港和斐济，槽线是从低压中心延伸出来或是画在两个低压中心之间的粗线。在澳门及澳大利亚，槽线则是用点线表示。

有时，处于两个高压中心之间的区域，若地表有风向切变，可以判定有槽存在。如果没有风向切变，该区域称为鞍形气压场。

在中纬度地区槽的两侧具有温度差，以锋的形式存在。锋的对流往往不如槽强烈，消亡的锋面系统有时会转为槽。

A trough is an elongated region of relatively low atmospheric pressure, often associated with fronts.

Unlike fronts, there is not a universal symbol for a trough on a weather chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked as a dashed line. In the UK, Hong Kong and Fiji, it is represented by a bold line extended from a low pressure center or between two low pressure centers; in Macau and Australia, it is a dotted line. If they are not marked, troughs may still be identified as an extension of isobars away from a low pressure center.