Cold Fronts

Active cold fronts and returning warm fronts from the Gulf produce the most adverse weather conditions experienced in the Pensacola region.

The movement of winter frontal systems through the area depends on the trajectory of the air mass behind the front, the strength of the Bermuda High, and the 500 mb flow associated with the frontal system.  Active cold fronts generally begin to reach this area in October and continue through April, reaching a frequency peak in December and January.

1) If the Bermuda High is in its normal position, another high that moves down the Mississippi Valley to north Texas, then eastward, will move the cold front through the local area and well into the Gulf. 

During fall, early winter and spring, cold frontal systems pass through the local area with cloudy conditions persisting for 36-48 hours after the front has passed.  A sharp 500 mb trough will accompany these systems. There will be clearing in the low levels with the passage of the 850 mb trough. Mid and high cloudiness will remain until the 500 mb flow has veered from a southwesterly to westerly to northwesterly flow. 

2) Alternately, cold fronts in the local areas may be associated with wave development on quasi-stationary frontal systems. This normally occurs when a wave develops in the southwestern Gulf and moves northeast.  The wave center moves inland usually around Lafayette, Louisiana. The cold front trails the wave center southwest into the western Gulf. The low center tracks northeast, and the cold front moves in relation to the low.  Typical cold frontal weather is experienced during passage.  Rapid clearing follows frontal passage.

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