PIREPs are the only means of precisely determining _____ and ______ weather conditions.

When ceiling is at o below 5,000 feet and visibility is less than 5 miles, controllers are obligated to _____ PIREPs

A decrease in temperature with an increase in height is called an

Two types of barometers used to measure atmospheric pressure are _______ and _______.

In a METAR, temperature and dew point are shown in whole degrees ________

Anticipate _______ when temperature-dewpoint spread is 5 degrees or less and decreasing.

An increase in temperature of the atmosphere with an increase of altitude height defines a(n)

Weather advisories issued to amend an area forecast regarding weather phenomena that are of operational interest to all aircraft and potentially hazardous to aircraft are classified as

Weather advisories issued for extreme turbulence and severe icing are classified as

Advisories for existing and forecast weather involving tornadoes, embedded thunderstorms are classified as

In the troposphere, the lapse rate is approximately ______ degrees Celsius per one thousand feet

Convective currents are the result of

In the Northern Hemisphere, air movement around a low pressure center flows in a(n) ________ direction

The uneven heating of adjacent bodies of air cause warm air to be drawn upward and more dense are downward defines

A narrow, high speed, meandering band of air moving at a high altitude is called a

What are the two basic classifications of clouds?

Clouds formed by vertical currents of unstable air are called ______ clouds

Clouds formed by the cooling of stable air are called ________ clouds.

When a mass of cold air replaces warm air, a _______ front occurs

A squall line is a narrow band of

Warm air slides over a wedge of colder air when a _______ front progresses forward

Behind a fast moving cold front, you can expect ________ skies with gusty and turbulent winds.

The weather phenomenon particularly hazardous to aviation is ________

The three principle types of fronts are cold, warm, and ______

One of the most common and persistent weather hazards encountered in aviation is

The most frequent cause of surface visibility below 3 miles is

The most common forms of precipitation that cause restrictions to visibility are

Rain rarely reduces surface visibility to less than________ mile(s)

Three types of structural icing are clear, mixed, and _____

When accumulation of aircraft icing is such that deicing/antiicing equipment fail to remove or reduce it, the icing intensity is reported as

Clear ice is considered dangerous to aircraft in flight because it is

Small, dangerous downdrafts of wind extending horizontally 2.5 miles or less with wind speeds up to 150 knots are called

Clear Air Turbulence (CAT) most generally occurs at high altitude and in the vicinity of

The initial stage of a thunderstorm occurs in a _______ cloud.

The mature stage of a thunderstorm is reached when ________ begins.

Airports equipped with LLWAS-Network Expansion (LLWAS systems integrated with TDWR and TDWR systems) provide the capability of detecting wind shear alerts and

Two thunderstorm hazards to aircraft are hail and

A violently rotating column of air in contact with the ground and associated with a thunderstorm is called a

Pressure, temperature, and humidity are used to determine _______ altitude

What type of Aviation Routine Weather Report would be generated when a wind shift occurs?

An Aviation Routine Weather Report taken after an aircraft mishap is called a ________ observation.

A change in wind speed and/or direction in a short distance is called a

In a METAR report, the height of a cloud base is reported in _________ of feet AGL.

Broken sky cover means that ______ to 7/8 of the sky is obscured by clouds.

Station identifiers for all weather reporting stations in the conterminous United States will begin with the letter

The greatest distance that can be seen throughout at least half of the horizon circle describes _________ visibility.

"+TSRAGR" encoded in a METAR indicates a

Wind direction is determined by the direction __________ the wind is blowing.

Wind speed is the average speed given in

The standard pressure at sea level is ______ inches of mercury.

The METAR entry "SCT020 BKN250" is decoded as

The METAR entry "FEW025TCU SCT040" is decoded as

"CIG 005V008" in the remarks sections of a METAR indicates

In a METAR report, the altimeter element follows the ______ group

A very small downward gust of air (2.5 miles or less in diameter) is called a

Tower personnel shall take prevailing visibility observations when prevailing visibility at the usual point of observation or at tower level is less than _______ mile(s)

A SPECI will be taken when