Gold Seal Weather Flashcards
define
Ceiling
– Lowest layer of broken or overcast clouds
define
IFR conditions
ceilings, visibilities
Ceilings less than 1,000 feet or visibilities less than three statute miles
define
MVFR conditions
ceilings, visibilities
Ceilings between 1,000 and 3,000 feet AGL or visibilities from three to five statute miles
reports
AIRMET
what is…
An AIRMET is an advisory of significant weather conditions primarily of interest to smaller aircraft.
Issued every six hours, AIRMETs report IFR conditions, moderate turbulence, moderate icing, and surface winds of 30 knots or greater.
reports
SIGMET
define…
advisory of non-convective conditions hazardous to all aircraft. SIGMETs report severe turbulence, severe icing, and obscurations due to duststorms or volcanic ash. SIGMETs forecast
conditions for a maximum of four hours.
reports
Convective SIGMET
define…
SIGMET associated with thunderstorms. SIGMETs forecast conditions for a maximum of 2 hours.
how often
METARs
hourly observation at an airport
define
TAFs
24-hour forecast of conditions expected within five statute miles of an airport. Issued every six hours: 00, 06, 12,18 Zulu
define
Aviation Area Forecasts
general weather forecast that covers several states and uses abbreviations similar to those used in TAFs. They are issued three times a day.
define
Severe Weather Outlook Charts
a two-panel chart that presents a 48-hour forecast of thunderstorms and severe thunderstorms, indicating expected areas of coverage. Issued 5 times a day.
define
Surface Analysis Charts
overview chart
Generated every three hours, a Surface Analysis Chart shows fronts, winds, and temperature/dewpoints across the contiguous United States. This is the type of overview chart that you usually see in newspapers and on television weather reports.
define
Significant Weather Prognostic Charts
Surface Analysis chart shown as a forecast in increments of 12 hours into the future. Nothing special except that the aviation version outlines areas of IFR, MVFR, significant turbulence, and freezing levels.
define
Weather Depiction Charts
The Weather Depiction Chart shows fronts, cloud coverage at reporting stations across the country, and outlines current areas of IFR and MVFR. It is peppered with small circles that represent reporting
stations. The circles are filled in to indicate cloud cover.
define
Freezing Level Charts
Freezing Level Charts are dedicated to identifying current areas and altitudes where
freezing temperatures exist.
what is…
HIWAS
A recorded broadcast of hazardous weather transmitted over the voice channel of some VOR
stations. You can locate them on your sectional. The availability of HIWAS will be indicated by a small
circle with the letter “H” in it within the VOR information box.