Winds. Winds on a weather map are represented by wind barbs; e.g., Notes:

Transcription

1 Winds Winds on a weather map are represented by wind barbs; e.g., flag half flag pennant wind direction The wind is blowing from the side with the flags and pennants (think an arrow with feathers) Speeds are given by: pennant: 50 knots flag: 10 knots half flag: 5 knots = 75 knots

2 Winds Winds on a weather map are represented by wind barbs; e.g., flag half flag pennant wind direction The wind is blowing from the side with the flags and pennants (think an arrow with feathers) Speeds are given by: 1 knot = 1 nautical mile hr = 1.15 mile hr = 1.85 km hr = 0.51 m s

3 The Station Model The data reported at a weather station looks like (in simplified form): wind (15 knots) temperature precipitation pressure dew point 63 pressure trend cloud cover

4 The Station Model The data reported at a weather station looks like (in simplified form): wind (15 knots) Winds use the same scale as before; i.e., pennant: 50 knots flag: 10 knots half flag: 5 knots

5 The Station Model The data reported at a weather station looks like (in simplified form): temperature dew point 63 In the US, the temperature and dew point temperature are given in o F. Everywhere else it's o C.

6 The Station Model The data reported at a weather station looks like (in simplified form): precipitation Precipitation types are represented by symbols: light rain moderate rain heavy rain ** ** light snow * moderate snow freezing rain and others...see Appendix C (or wikipedia)

7 The Station Model The data reported at a weather station looks like (in simplified form): cloud cover Shading of the station dot shows the extent of cloud cover: clear half coverage full coverage (overcast) etc...see Appendix C for details

8 The Station Model The data reported at a weather station looks like (in simplified form): pressure trend The trend line shows the change in pressure over the past 3 hours: steady (no change) falling rising falling, then rising etc...

9 The Station Model The data reported at a weather station looks like (in simplified form): pressure The pressure is shown using a three-digit code; i.e.,: mb mb mb

10 The Station Model The data reported at a weather station looks like (in simplified form): pressure The rule of thumb is If the three-digit code is less than 500: Add a 10 in front and a decimal before the last digit hpa If the code is greater than 500: Add a 9 in front and a decimal before the last digit hpa

11 Upper Levels (e.g., 500 mb) Data at upper levels is similar, but with a couple of changes: temperature height dew point depression 23

12 Upper Levels (e.g., 500 mb) Data at upper levels is similar, but with a couple of changes: dew point depression 23 Instead of the dew point temperature, we get the dew-point depression, defined as: depression = temperature dew point temperature

13 Upper Levels (e.g., 500 mb) Data at upper levels is similar, but with a couple of changes: temperature dew point depression Somewhat inexplicably, the temperature and dew point depression are given in o C. (Remember the surface temperature was o F.)

14 Upper Levels (e.g., 500 mb) Data at upper levels is similar, but with a couple of changes: height Instead of pressure, we get the height of the surface, in units of decameters (or 10 m) m

15 Frontal Symbols front warm front stationary front for the, warm and occluded fronts, the symbols show the direction of motion occluded front

16 Frontal Symbols warm front warm front stationary front for the, warm and occluded fronts, the symbols show the direction of motion occluded front

17 Frontal Symbols warm warm front warm front stationary front for the, warm and occluded fronts, the symbols show the direction of motion occluded front

18 Frontal Symbols warm warm warm front warm front stationary front for the, warm and occluded fronts, the symbols show the direction of motion occluded front

19 Frontal Symbols warm warm warm er front warm front stationary front occluded front for the, warm and occluded fronts, the symbols show the direction of motion