Transcript “Making the Invisible Visible: Monitoring Weather - Hewlett

Aim: What are station
models?
Do Now: Explain why we would
put symbols on a map instead of
the actual information.
Representing Weather with a
“Station Model”
National Weather Service (NWS)
meteorologists use a simple system to
represent the weather at a location. A circle
on a map identifies the location. Numbers
and symbols added to the circle indicate the
kind of weather instruments at that station
have measured.
The next set of slides will explain how this
is done.
Temperature
 Air temperature is shown in Fahrenheit
degrees by the number to the upper left of
the circle.
75
Dew Point Temperature
 The dew point temperature in Fahrenheit
degrees is shown to the lower left of the
circle.
57
Wind Direction and Speed
 Wind direction is show by an
“arrow” going into the circle.
The example shows wind
blowing from the lower right,
so this is a southeast wind.
 Each long “feather”
represents 10 knots and each
short “feather 5, so the wind
speed is 25 knots.
Cloud Cover
 The amount of the circle that is filled in
indicates how much of the sky is covered by
clouds.
 It may range from “clear” (left) to “overcast”
(right).
“Present Weather”
 When rain, snow, or
other forms of
precipitation, lightning,
and special weather
conditions exist, these
are shown by symbols
to the left of the circle
between air
temperature and dew
point temperature
rain
showers
thunderstorm
*
snow
Pressure
 Pressure—measured in mb (millibars)—is
given by the number to the upper right of
the circle
 For example, suppose it’s 1019.4 mb
 Only the 10s/1s/0.1s are shown—so it is
represented as 194
194
• Pressures below 1000 mb would start with
high numbers, such as 964 for 996.4 mb
Station model
milibars
020
956.3
1002.1
567
987.6
1009.7
749
942
234
Station model
Milibars
020
1002.0
563
956.3
021
1002.1
567
956.7
876
987.6
097
1009.7
749
974.9
942
994.2
234
1023.4
Barometric pressure
Barometric trend
055
/11
899
\21
888
/09
100
\14
020
\02
999
/99
789
/67
234
\23
987
\42
Barometric trend
three hours ago
Barometric pressure
Barometric trend
Barometric trend
three hours ago
055
/11
1004.4
899
\21
992.0
888
/09
987.9
100
\14
1011.4
020
\02
1002.2
999
/99
990.0
789
/67
972.2
234
\23
1025.7
987
\42
1002.9
Try to interpret this station model
1. Temperature: 45 o F
2. Pressure: 1004.5 mb
6
o
3. Dew Point: 29 F
4. Clouds: overcast
5. Wind: from southeast at
15 knots
6. Precipitation: light rain
2
1
4
3
5
Station model plot
 http://cimss.ssec.wisc.edu/wxwise/station/ex
ample1.html
 http://profhorn.meteor.wisc.edu/wxwise/stati
on_model/index.html