Weather Whiz Flashcards
Define GFA
Graphic Area Forecast
Usually issued every 6hrs, for AC operating within 1000NM and below 240.
SIGMET
Significant Meteorological Phenomen
Significant weather that WAS already inlcuded in the GFA
AIRMET
Significant weather that was not previously included in the GFA.
TAF
The Aerodrome Forecast
Intended to relate to weather conditions within 6SM (5NM) of the runway.
How many hourly obs are required for a TAF to be made?
Two consecutive
ABV VC
Vicinity
ABV MI
Shallow
ABV BC
Patches
ABV PR
Partial (covering part of the aerodrome)
ABV GR
Hail (larger)
ABV GS
Hail (small) or snow pellets
Two types of GFA
-Clouds and weather
-Icing, turbulence, and freezing level.
GFA symbol that Looks like a capital R with an arrow on the tail
TS
GFA symbol that is a triangle with a dot in the middle of it.
Ice pellets
.~
Freezing Rain
,~
Freezing Drizzle
)=
Moderate Icing
) with 3 lines
Severe Icing
^
Moderate Turbulence
^ with two ^
Severe Turbulence
ISOL
Isolated (25% or less of the area)
STNR
Stationary (moving at a speed of less than 5kts)
OCNL
Occasional (25-50% of the area)
FREQ
Frequent (Greater than 50%)
LCA
Local (Less than 25% of an area)
PTCHY
Patchy (25-50% of an area)
Xtnsv
Extensive (Greater than 50%)
Light Icing
Ice accretion is such that flying for more than one hour without deicer may create a problem
Moderate Icing
Ice accretion is such that flying for even a short amount of time without deicer can be hazardous. Deicer or a diversion are necessary
Severe Icing
Ice accretion is such that deicer wont mitigate the problem. a diversion is necessary.
What are the 5 types of turbulence?
-CAT
-Mech
-MTW
-L LVL JET
-L LVL WS
Light Turbulence
Such turbulence momentarily causes slight, erratic changes to the altitude or attitude of the AC.
Moderate Turbulence
Similar to light, but more frequent. The AC is always in positive control.
Severe Turbulence
Such turbulence causes large, abrupt changes in altitude or attitude of an AC.
CAT
Clear Air Turbulence: Turbulence in the absence of clouds. Caused when masses of differently moving air meet.
Mech
Mechanical Turbulence: Caused by friction between the air and ground, over uneven land masses or man made structures.
MTW
Lee waves (Mountain Waves): Caused by stationary waves on the sheltered side of a mountain.
LLWS
Low Level Wind Shear: When there are significant differences in wind in a small vertical distance.
A wind shear of 10 knots or more per 100 feet in a layer more than 200 feet thick which occurs within 2,000 feet of the surface
L LVL Jet
Turbulence caused by high speed winds (jet streams) in low levels of the atmosphere. Included in GFA when 50kts or more.
Which way does wind travel around a L pressure system?
Counter clock-wise
Which way does wind travel around a H pressure system?
Clock-wise
How is the area of the GFA applicable to you identified?
It is within a scalloped, red border, indicating the layer of cloud affecting the area.
How is obstruction to vision shown on GFA?
Orange, hyphenated border
Continuous precip on GFA
Green border with dots inside
Intermittent precip on GFA
Hyphenated green border with lines inside
Continuous freezing precip on GFA
Red border with dots inside
Intermittent freezing precip on GFA
Red, hyphenated border with lines inside.
Moderate Icing on GFA
Blue border with fewer dots
Severe Icing on GFA
Blue border with more dots
Moderate LLVL turbulence on GFA
Red border with fewer lines going from right to left.
Severe LLVL turbulence on GFA
Red border with more lines going from left to right
Moderate HLVL turbulence on GFA
Red border with fewer lines going from right to left.
Severe HLVL turbulence on GFA
Red border with more lines going from right to left.
Freezing level on GFA
Represented by a hyphenated black line.
