Section 5 Flashcards
How often are Surface Analysis Charts transmitted?
Every three hours
Are surface analysis charts forecasts or reports?
Reports
Solid lines depicting sea level pressure patterns are called
Isobars
Isobars are usually spaced out in intervals of
4 millibars
When overall pressure gradient is weak, dashed isobars are inserted at ____ intervals to more clearly define the pressure pattern.
2 millibars
L on a surface analysis chart means?
Low pressure center
H on a surface analysis chart means?
High pressure center
The symbols on a front point in the direction the front is
heading to
Two short lines across a front indicates ________ of front ___________
Change Type
A trough will be depicted as
thick dashed line
Aviation surface analysis chart will contain:
Temperature in F, wind (kt), ceiling, sky cover, visibility, weather
Visibility less than 1sm are coded as
0
Where could you look to find the visibility if it said 0?
METAR
What are surface analysis charts mainly used for?
Pressure systems and Fronts
Are Radar charts reported or forecast weather?
Reported
Radar images are primarily used to identify areas of
Precipitation
Echoes displayed indicate the _______ of precipitation
Intensity
What are the four levels of intensity for precipitation (RADAR)
light, moderate, heavy, extreme
What does Tornado Watch mean?
severe weather is possible during the watch valid time
What does Tornado Warning mean?
Severe weather has been observed or is expected within the hour.
Convective precipitation echoes tend to form as ___________
lines or cells
Which is better at detecting embedded CBs? Aircraft on board radar or surface based radar?
Surfaced based radar
Upper air sounding are _____________ weather
reported
Upper air sounding are issued how many times per day?
2
lifted index is a measure of atmospheric ___________
stability
What does a positive LI value mean for a lifted surface parcel?
it is stable
What does a negative LI value mean for a lifted surface parcel?
it is unstable
What would a LI value of -6 or less mean?
Very unstable air
KI value is and indicator of the _________
and coverage of storms.
Probability
Large positive KI value implies _______
moist and unstable air
winds and temperatures aloft charts is a ___________ weather.
forecast
Winds and Temperature Aloft charts are published how many times per day?
4
What unit is used for Winds and Temperature Aloft Charts?
Celsius
In Winds and Temperature aloft charts do positive and negative temps both have signs TRUE/FALSE
FALSE
Positive temps will not have signs
Wind direction in a Winds and Temp aloft chart are in reference to __________ North?
TRUE
G-Airmets will display moderate or severe conditions?
Moderate
What kind of weather does G-Airmets exclude?
Convective
Short-Range SFC Prog charts are _______
weather?
Forecast
How often are Short-Range SFC Progs issued?
4 times a day
What does the green area represent on a Short-range SFC Prog?
Possibility of rain
If weather is likely in a Short-Range SFC Prog what is the percentage of probability?
More than or equal to 55%
To what height does a low level prog chart start and extend to?
Surface to FL240/400mb
Solid lines on a low level prog chart represent?
Ceiling less than 1000ft and or VV less than 3sm (IFR conditions)
Scalloped lines on a low level prog chart represent?
ceiling 1000-3000 ft and or VV 3-5 sm
(Marginal VFR)
Freezing levels aloft on a Low level prog chart are depicted by
dashes
Moderate or greater turbulence/CAT on a low level prog chart are depicted by
bold long dashed lines enclosing the area
What is omitted on a low level prog chart when turbulence reaches the surface?
base
What is depicted by zig-zag lines on a low level prog?
freezing level at surface
