402.2d - visibility, wind shifts, and turb associated with weather

Visibility can be reduced well in advance of warm fronts because of ____ and the ____.

the shallow slope, generally large band of cloud and precipitation

Ahead of cold fronts, visibility is generally ___. Close to the front, visibility may be reduced in _____.

good, precipitation and mist

After the passage of a cold front, there will usually be ______ in visibility. The air behind the front is usually unstable, and the vertical currents will carry _____.

a marked improvement, suspended particles aloft

Any part of an air mass that is _____ and has recently passed over an industrial region will be loaded with ____ and have poorer visibility than usual

stable, pollutants

Which type of front has reduced visibility well in advance of the front?

Warm front

Before a cold front arrives, the wind ahead of the front is typically out of ____. Once the front passes through, the wind will usually ____ around to _____.

the SSW, veer around, the WNW

Before a warm front arrives, the wind ahead in the front is typically from _____, but once the front passes through, the wind usually _____ to ____.

the east, veers around, the SSW

The wind shift that occurs at the frontal surface is most significant ___. The wind shift associated with flight through a front is more abrupt ____.

in the lower levels, at a cold front than a warm front

Most ____ bring clouds, showers, and a wind shift, while ____ tend to bring fewer clouds and drier weather.

troughs, ridges

Whatever direction an aircraft flies from, when crossing a frontal surface, the aircraft will have to correct its heading _____.

to the right

A dry front can conceal many hazards. The main indicator of turbulence, even in clear air, is the ______ across the front at the surface. If it drops suddenly by ____ at the surface even without the expected cloud development, you are probably experiencing frontal passage.

temperature difference, 5 degrees Celsius

Wind shear occurs if the cold front is moving at ______.

30 knots or more

The degree of turbulence depends on the magnitude of the wind shear, and the amount of shear will depend on the ______. Frontal wind shear is a phenomenon associated with _______ but can be present in warm fronts as well.

the temperature contrasts between the two air masses, fast moving cold fronts