IRFP-01
Metro Review
II. Fronts and resulting winds 21.1.1.2.5, 21.1.1.2.5.1
A. Cold front
Fig 1: Cold Front
1. Characteristics
a. Predominantly cumuliform type clouds
b. Thunderstorms and occasional squall lines (seasonal)
c.
Turbulence and unstable air
d. Strong, gusty winds
e. Showery precipitation
f.
Clearing skies and good visibility after frontal passage
2. Wind changes
a. Before passage, wind flows parallel to (along) the front
b. After passage, wind flows perpendicular to front
(1) Follows prevailing wind in same direction as front
movement (perpendicular to front)
(2) Generally stronger due to steeper pressure gradient of
colder air mass
B. Warm front
Fig 2: Warm Front
1. Characteristics
a. Predominantly cirriform and stratiform type clouds
b. Predominantly stable air and little turbulence
c.
Continuous precipitation ahead of front in wide area
d. Poor visibility from haze or fog
e. Icing conditions
2. Wind changes
a. Before passage, wind flows parallel to front from higher to
lower pressure
b. After passage, wind flows perpendicular to front
(8-97) Original
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