Aviation Weather Services and Navigation Time Conversions

Vocabulary terms and definitions focusing on preflight weather briefings, soaring and ballooning atmospheric indicators, and universal time zone conversions for navigation.

Standard Briefing

A complete preflight weather briefing that a pilot should request any time a flight is being planned and no previous briefing has been received.

Abbreviated Briefing

A weather briefing requested by a pilot to supplement mass disseminated data, update a previous briefing, or obtain only one or two specific items.

Outlook Briefing

A weather briefing provided for planning purposes only, requested whenever the proposed departure time is $6$ or more hours in advance of the briefing.

Flight Service Initial Pilot Identification

The requirement that a caller initially identify themselves as a pilot (or state the aircraft tail number) and state whether the planned flight will be flown under VFR or IFR.

Thermal Index

An index computed for any level using upper soundings to approximate the temperature difference between sinking cold air and rising warm air to evaluate soaring conditions.

Thermals

Convective rising air currents produced by atmospheric instability, whose vertical height depends on the depth of the unstable layer and whose strength depends on the degree of instability.

Growing Cumulus

A cloud with a firm and sharp outline that forms with a rising thermal, indicating positive thermal activity existing at least to the tops of the scattered clouds.

Stratiform Clouds (Balloon Operations)

Clouds that indicate an absence of turbulence, which in combination with surface winds of $5\text{ knots}$ or less, indicate good flight conditions for balloons.

Aviation Routine Weather Report (METAR)

The weather report that provides local surface observation information, serving alongside Winds Aloft Forecasts as the most important reports for local balloon operations.

Coordinated Universal Time (UTC / ZULU Time)

The international reference time used in flight planning and navigation, calculated by applying specific standard time zone offsets to local standard time.

Central Standard Time (CST) Conversion

The conversion factor used to calculate UTC from Central Standard Time, accomplished by adding $0600$ ($+0600$) to the local CST time.

Mountain Standard Time (MST) Conversion

The conversion factor used to calculate UTC from Mountain Standard Time, accomplished by adding $0700$ ($+0700$) to the local MST time.

Pacific Standard Time (PST) Conversion

The conversion factor used to calculate UTC from Pacific Standard Time by adding $0800$ ($+0800$), or used to convert UTC to PST by subtracting $0800$ ($-0800$).