1. Weather Map…Without Data!

2. What data are necessary?
Temperature
Cloud Cover
Wind
Visibility
Air Pressure
Present Weather
Precipitation
Humidity
How can all these be put in such a small spot?

3. The Weather Station Model

4. How to MAKE and READ a STATION MODEL
TURN TO ESRT p 13 NOW!!
Temperature…
Simply read the temperature…
Cloud Cover…75% cloud cover
Visibility… ½ mile
Humidity…
Read the Dewpoint 27oF
Precipitation… 0.25 inches in the last 6 hours

5. But any one of these symbols might be used!
What was the present weather on the station model?
But any one of these symbols might be used!

6. WIND 5 10
FROM the SW
NE at 25 Knots
E at 5 Knots
SE at 10 Knots

7. Barometric Pressure or AIR PRESSURE Now we’ll crack the code!
It is written in a secret code on the station model…
Now we’ll crack the code!

8. 196 19.6 1019.6 969 96.9 996.9 Decoding the Coded Pressure
Example code…
196
Insert a decimal between last 2 digits
19.6
If 1st digit is between 0 and 5 put a 10 in front!
1019.6
The actual barometric pressure is millibars (mb) How many “inches” is that?
Example Code:
969
Insert a decimal between last 2 digits
96.9
If 1st digit is between 6 and 9, put a 9 in front!
996.9
The actual barometric pressure is millibars (mb) How many “inches” is that?
1000.2
999.3
Decode these Station
Model pressures:
It’s a SNAP!
1028.0
1000.0

9. 19 means the pressure has changed by 1.9 mb
The Barometric
Pressure Trend
+ means Higher now than 3 hours ago
- means Lower now than 3 hours ago
19 means the pressure has changed by 1.9 mb
/ means pressure is rising
\ means pressure is falling
“The pressure is 1.9 mb higher and rising”

10. What are the conditions shown by the model?
Temperature= 45F
Dewpoint= 32F
Wind NE at 20 knots
Overcast
Rain Showers
Pressure Now= mb
Pressure has fallen 2.9mb in the past 3 hours
Precipitation in last 6 hrs.= .53 in.

11. Encoding the Pressure
1013.5
Remove the decimal point from the actual pressure
10135
The last 3 digits are the code to use for the station model!
135
Actual Pressure = 135 pressure code
Encode these pressures:
327
873
122
001
©S. Kluge 2007