MET 4710/5710-LOL: Broadcast Meteorology I
Notes: Surface Data

Station Model

Weather Stations

Sable Island, NS New England area Station Model
  • Weather stations consist of an array of instruments designed to collect a variety of meteorological parameters. Station WSA on Sable Island, NS is representative of a well equipped automated station(Click on images).
  • Station data is plotted on maps using the station model shown here. Click on images.

  • Complete station model
  • Search for station id here
  • List of Stations in North America

    Cloud cover(overcast)

  • Cloud cover information (if available) is plotted in a circle at the station location.
  • The fraction of sky covered in cloud is represented in eights.

  • Cloud classification scheme identifies cloud type on some station models (human observing stations only).

    Wind (Northwest at approx. 15 knots)

  • Wind barbs point in the direction that the wind is coming from. The barb in the example indicates a northwesterly wind (coming from northwest) blowing southeastward.
  • Ticks indicate windspeed in increments of 5 knots. In the northern (southern) hemisphere, ticks are drawn to the right (left) of the wind barb.
  • Windspeed conversion from NWS

    Weather symbol

  • Weather symbols indicate the presence of precipitation, fog, and other suspended particles that might interfere with visibility.
  • The following chart offers a key to the most common weather symbols.
  • More comprehensive chart can be found here.

    Pressure

  • Reduced sea-level pressure (SLP) indicates the station pressure extrapolated to sea-level.

  • Units are in 1/10 millibars. Since SLP is usually between 950 and 1050 mb, the initial "9" and "10" are omitted
    (eg: 989.1 mb => 891, 1006.1 => 061 , 999.1 = 991; 1023.0 => 230 )

    3-hr pressure tendency

  • The change in pressure is also given in tenths of millibars
  • values are followed by a symbol describing pressure fluctuations in the previous 3 hrs.

    Temperature:

  • Temperature is given in Celsius on Canadian maps and in Fahrenheit on most American maps.
  • Conversions are based on the following formula: F = 9/5 C + 32
  • Conversions can also be done by remembering that O C and 32 F represent the freezing point ] of water and and that adding 9 F for every 5 C will yield equivalent values.
  • The following table may be useful
    C -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35
    F -22 -13 -4 5 14 23 32 41 50 59 68 77 86 95

    Dew Point Temperature:

  • The dewpoint temperature (or dewpoint) is a measure of water vapour in the atmosphere. It is the temperature at which the water vapour will begin condensing, so that higher dewpoints mean that nore water vapour is present. Fog and precipitation often yield dewpoint readings equivalent to temperature. Dewpoints higher than temperature are vaery rare anf likely indicate faulty data.

    • METAR

    • Meteorological aviation reports (METARs) are hourly reports that serve aviation interests. Special off-hour reports (SPECI) record unusual or severe weather conditions. At large airports, these observations are performed manually by human observers. At most other locations, automated weather stations gather the data. The data are fed instantaneaously into global satellite networks.
      Guides Decoding Keys
    • Format METAR STATION TIME AUTO WIND VISIBILITY WEATHER CLOUDS TEMP/DEW ALTIMETER REMARKS 
      Sample 1

CYUL 081700Z 24018G25KT 10SM BKN028 27/20 A2975 RMK CU6 TCU ASOCTD SLP073=  
CYUL 081800Z 23019G24KT 10SM FEW028TCU SCT070 SCT240 27/20 A2972 RMK TCU2AC1CI0 SLP065= 
CYUL 081900Z 23022G27KT 10SM FEW028TCU BKN220 29/20 A2970 RMK TCU2CI2 CB ASOCTD SLP056=  
CYUL 081947Z 24016G24KT 10SM -SHRA FEW025TCU BKN070 BKN240 RMK TCU2AC3CI1=  
CYUL 082000Z 31013G20KT 7SM -TSRA FEW015 BKN030CB BKN070 26/22 A2971 RMK CF1CB5AC1 SLP061=
      STATION CYUL Dorval Airport
      TIME 082000Z Time 8th of month, 1900Z
      AUTO nr manual observation station
      WIND 31013G20KT sustained wind from 310 degrees (W-SW) at 13 knots, gusting to 20 knots
      VISIBILITY 7SM 7 statute miles
      WEATHER -TSRA - light thunderstorm and rain
      CLOUDS FEW015 BKN030CB BKN070 Few clouds at 1500 ft, Broken cloud at 3000 feet; broken cloud at 7000
      TEMPERATUE 26/22 temperature 26C, dewpoint temperature 22C
      ALTIMETER A2972 (surface pressure) 29.72 inches of mercury
      REMARKS RMK remarks follow
      Cloud type CF1CB5AC1 cumulus fractus covering 1/8 sky at low level ; cumulonimbus covering 5/8 of sky at mid-level altocumulus covering 1/8 of sky at upper level
      Sea-level pressure SLP061 Sea-level pressure 1006.1 mb 
      Sample 2

CWTA 081800Z AUTO 22006KT 27/20 RMK AO1 PK WND 22017/1702 SLP068 T02670203 58017=  
CWTA 081900Z AUTO 22007G17KT 27/20 RMK AO1 PK WND 18017/1853 SLP060 T02730204 58020=  
CWTA 082000Z AUTO 23005KT 26/20 RMK AO1 SLP062 T02590200 55015=  
CWTA 082100Z AUTO 19004KT 25/20 RMK AO1 PAST HR 8007 SLP061 P0013 T02520202 50034=
    Station CWTA McTavish Reservoir (McGill)
    TIME 082100Z 8th of month, 2100Z
    AUTO

    		AUTO automated station
    WIND 19004KT sustained winds from 190 degrees (S-SW) at 4 knots
    VISIBILITY nr nr
    WEATHER nr nr
    CLOUDS nr nr
    TEMPERATUE 28/18 temperature 25C, dewpoint temperature 20C
    ALTIMETER nr nr
    REMARKS RMK remarks follow
    station type AO1 automated station with rain guage
    Sea-level pressure SLP067

    		sea-level pressure 1006.1 mb
    Precipitation P0013 1 hr accumalated melted precipitation
    Temperature T02780179 temperature 25.2 C, dewpoint 20.2 C
    Pressure tendency(3-h) 50034 5 - indicates pressure tendency; 0 - rising then falling; net pressure rise 034 - 3.4 mb/3 hr

    Links

    Some links to METAR reports (to change station, change station code in the location URL of your browser):
    Raw METAR Decoded METAR Data Archives
    Other useful links