103W: NC-SWOP, MANOBS and Types of Weather Observations

What is the primary purpose of surface weather observations according to NC-SWOP?

To provide aviation users with detailed weather and climate information for safe and efficient operations.

When must an observer give the highest priority to their weather observing duties?

When the imminent occurrence of severe weather conditions requires the rapid dissemination of a warning or advisory.

What is the name of the international meteorological code for an Aviation Routine Weather Report taken on the hour?

METAR

A _____ is an aerodrome Special Meteorological report issued when selected changes in weather conditions significant to aviation occur off the hour.

SPECI

What does the acronym HWOS stand for?

Human Weather Observation System.

In HWOS, which observations can be corrected during the current hour?

Only the current METAR and the last SPECI observation processed during the current hour.

According to NC-SWOP, how early can an hourly observation be started, and by when should it be transmitted?

Observations may start as early as six minutes prior to the observation hour and the hourly must be transmitted before seven minutes past the hour

If more than one weather element changes enough to trigger a SPECI, what time is used for the observation?

The time of observation of the element considered to be the most important to aviation.

What two types of remarks in a METAR/SPECI are excluded when relayed to an aircraft?

Cloud types (unless TCU or CB) and cloud amounts, and sea level pressure data.

What is the correct phraseology for the wind code '00000KT'?

WIND CALM

Decode the following wind report into correct phraseology: '01015KT 340V040'.

WIND ZERO ONE ZERO AT FIFTEEN VARIABLE BETWEEN THREE-FOUR-ZERO AND ZERO-FOUR-ZERO.

What is the correct phraseology for the Runway Visual Range trend 'D'?

DOWNWARD TREND

What is the phraseology for the sky condition 'VV'?

VERTICAL VISIBILITY

What is the correct phraseology for the sky condition 'BKN015'?

CEILING ONE THOUSAND FIVE HUNDRED BROKEN

What does the METAR remark 'PRESRR' stand for?

PRESSURE RISING RAPIDLY

What does the lightning remark 'OCNL LTGICCG OHD' mean?

OCCASIONAL LIGHTNING IN CLOUD, CLOUD TO GROUND OVERHEAD

For an aerodrome without a 24-hour observing program, how many observations are required before a TAF can be issued?

Two consecutive hourly observations immediately prior to the issue time.

What is the only cloud type identified in a TAF?

CB (Cumulonimbus).

What does the change group 'FM' (FROM) indicate in a TAF?

A permanent and rapid change, where all forecast conditions before this group are superseded.

What does the change group 'BECMG' (BECOMING) indicate in a TAF?

A permanent change that is expected to occur gradually over a period of one to four hours.

The change group 'TEMPO' indicates a temporary fluctuation that is expected to last less than ____ in each instance.

one hour

The probability group (PROB) is restricted to what kind of weather elements?

Hazards to aviation, such as thunderstorms, freezing precipitation, low level wind shear, or significant ceiling/visibility values