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Stationary Fronts
Stationary fronts are a stalled boundary between two air
masses. They show little or no movement. The polar front jet is running
parallel to the front in the upper air, thus it provides little or no push.
Surface winds are also parallel to each other, but running in the opposite
directions across the front itself. As in warm fronts, precipitation and
stratiform clouds are found on the north side of the front.
Surface temperatures fall slowly ahead of the front and
rise gently after passage. There is a significant temperature gradient
on either side of the front. Following Petterssen’s Rule, this would be
the ideal area for new cyclogenesis. As in warm fronts, dew points are
relatively steady before passage and rise slowly after passage. Visibility
can vary widely, since there are many different influences on this front.
Fog, rain, and haze are not uncommon. Surface pressure ahead of the front
will slowly fall, but become steady during passage. Pressures will rise
slowly after passage. Surface winds blow parallel to the front, and veer
abruptly across it. These fronts can develop further, becoming cold
fronts, warm fronts, or undergoing cyclogenesis.
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