chapter Flashcards
it remains the one of the most useful charts for ascertaining current weather conditions just above the surface of the earth for a large geographic region. These maps are called
surface analysis
surface analysis charts if they contain…………………………… and……………………………..
fronts and analyzed pressure fields
surface analysis charts if they contain fronts and analyzed pressure fields, with the solid lines representing
isobars.
The word “synoptic “ is derived from
syn meaning the same or together and “optic” meaning visible
The weather data from each reporting station are plotted around these circles on these base maps in a particular systematic fashion
station model
air temperature and dewpoint temperature are reported in
whole (or integer) Fahrenheit degrees
the current near-surface air temperature and dewpoint temperature are reported in whole (or integer) Fahrenheit degrees. These temperatures are measured by instruments located in a standard instrument shelter at a height of approximately
5 feet above the ground
The value of the dewpoint may never exceed
the air temperature
wind speed and wind direction , are represented on the map by a combination of
a wind arrow shaft and wind barbs around the station model
These wind data are obtained from
a standard “anemometer height” of approximately 30 feet above the ground
the orientation of these wind arrows on the map indicates the wind direction to the
nearest 10 degrees
the orientation of these wind arrows on the map indicates the wind direction to the nearest 10 degrees, measured …………….. from …………………………………
clockwise from true north
By meteorological convention, the winds are named for the direction ………………………which they are blowing. Hence, a south wind is from ………………………………
from
the south
The number and length of the barbs on the tail of the arrow indicate the near-surface wind speed in
knots
nautical miles per hour, which are ……………………………..than the familiar statute miles per hour
15% larger
The current sea level corrected air pressure is plotted on the map to the upper right of the station model. The numeric pressure entries are in units of
tenths of millibars
The barometric pressure measured by a barometer at the station is………………………………………………..to eliminate the variations in reported pressure due to the …………………………………….of the station.
adjusted (or corrected) to sea level conditions
altitude
The amount of shading inside the station location circle is used
to depict sky cover, or the total fraction
usually refers to the sequence of operations involved with the organization of the plotted information on the weather map.
weather analysis
a major part of the analysis phase involves drawing
isopleths
lines connecting points of equal values
isopleths
While weather elements, such as temperature and pressure, are observed only at particular locations, we can assume that these elements are continuously distributed in the horizontal direction
meteorological field
Many of the surface analysis charts may contain……………………….to depict the features of the horizontal pressure field at …………………..
thin solid lines
mean sea level
H is colored
blue
L is drawn in
red
A trough of low pressure that contains
significant weather phenomena
A trough of low pressure that contains significant weather phenomena (such as precipitation and distinct wind shifts) may be identified on the map by a
thick brown dashed line running along the axis of the trough
temperature isopleth name:
Isotherms
Dew point isopleth name
Isodrosotherms
pressure isopleth name
Isobars
pressure change isopleth name
Isallobars
Wind speed isopleth name
Isotachs (Isovel)
Wind direction isopleth name
Isogon
Rainfall isopleth name
Isohyet
cloud amount isopleth name
Isoneph
Blue color:
snow and cold fronts
Red color:
Stratus cloud and warm fronts
yellow:
fog
brown
stratocumulus cloud
purple:
occluded front
black
troughs
green
rain/drizzle
The standard unit of pressure is millibars (mb or hectopascals-hPa) of which sea level is around
1015 mb
Because gravity decreases slightly with height, a modified type of height called ……………………………………is used that takes the variation of ………………………into account
“geopotential height”
gravity
most meteorological heights are strictly in units of
geopotential meters
