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  MADIS Surface Variables

Notes - MADIS Surface Variables

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  1. Dewpoint temperature and/or relative humidity are the moisture variables stored in the database. The user can select either of these variables, or select dewpoint depression, specific humidity, absolute humidity, or water vapor mixing ratio which will then be calculated by the MADIS API. If available, the stage 3 QC results from the dewpoint variable will be used for any of the calculated variables. If this isn't available, the QC results from the stored RH variable will be used. Also note that pressure is needed for the absolute humidity conversion; for the COOP dataset this is done by using the U.S. Standard Atmosphere calculation to calculate pressure from station elevation.

  2. As altimeter and station pressure can be calculated from each other, for datasets without altimeter (MARITIME) the altimeter will be calculated by the MADIS API, and for datasets without station pressure (METAR, SAO, 1-minute ASOS) that variable will be calculated as well. With the MESONET dataset, if the stored variable isn't the one requested by the user for each particular station, the calculated value will be returned. In all cases, the stage 3 QC from the altimeter variable (if available) will be applied.

  3. The 3 hour pressure change value consists of the numeric pressure change value, with a sign applied per the value in the character of 3h pressure change variable. The latter variable is coded:

           Value      Meaning
           -----      -------
             0        pressure same or higher than 3 hours ago
             1        increasing then steady
             2        increasing
             3        decreasing or steady, then increasing
             4        steady
             5        pressure same or lower than 3 hours ago
             6        decreasing
             7        steady or increasing, then decreasing
    

  4. Air temperature is the temperature variable stored in the database. The user can optionally select virtual temperature, which will then be calculated by the MADIS API. The QC results from air temperature will apply in either case. Also note that if virtual temperature cannot be calculated (missing or bad dewpoint or pressure), and the air temperature passed all QC checks, the air temperature will be returned instead, and a QC data descriptor value of "T" will be assigned. As with the absolute humidity conversion mentioned above, the virtual temperature conversion done for the COOP dataset uses pressure calculated from the station elevation.

  5. Wind speed and direction are reported and stored in the database. The user can optionally select u & v wind components and those will be calculated and returned. The QC results from speed and direction will be used In either case, and if one of the map projections has been selected via the MSETDOM call, the winds will be rotated to match the projection. The documentation in the COOP cdl was changed to remove the height of the anemometer. All anemometers are at 10 meters heights except for (GYX, TANM3, and STYN6) which are at 3 meters.

  6. Data platform type (MARITIME):

           Value      Meaning
           -----      -------
             0        stationary (moored buoy or CMAN)
             1        moving (drifting buoy or ship)
    

    Data platform type (1-minute ASOS):

           Value      Meaning
           -----      -------
             1        Federal ASOS
             2        Federal AWOS
             3        Federal AOS
             4        Non-fed ASOS
             5        Non-fed AWOS
             6        Non-fed AOS
    

    Data platform type (COOP):

           Value      Meaning
           -----      -------
           < 100      Phase II site (regional hub)
            100       Phase II site (GOES/HADS)
            200       Phase I site (direct connect)
            300       Phase I site (GOES/HADS)
    

    The modernized NWS Cooperative Observer sites can provide different variables, and on different schedules, dependent both on the type of site (Phase I or II) and on the processing done as part of reformatting the data sent over the various communications systems in use. Here are the primary differences:

    • Phase I sites only report a single temperature observation per hour, valid at minute 0.
    • Phase II GOES/HADS sites only report once per hour, but the reports contain 5-minute observations from the last hour.
        9/26/06: The Phase II GOES/HADS sites are being phased out, as part of
        an upgrade where the COOP network has been gradually rolling in a new
        software load over the last several months (and it's not done yet).
        The new load is indicated in MADIS as data platform types 2-99 (currently
        only 2 is in use).  This upgrade has changed what variables are available from 
        the Phase II stations.
        
        Variables that are no longer available for COOP PLATTYP 2 stations:
    
             TD1H      hourly average dewpoint temperature  
             RH        relative humidity                    
             RH1H      hourly average relative humidity     
             Q         specific humidity                    
             Q1H       hourly average specific humidity     
             DPD       dewpoint depression                  
             DPD1H     hourly average dewpoint depression   
             AH        absolute humidity                    
             AH1H      hourly average absolute humidity     
             WVMR      water vapor mixing ratio             
             TV        virtual temperature
             T1H       hourly average temperature           
             TV1H      hourly average virtual temperature   
             DD1H      hourly average wind direction        
             DD24H     daily average wind direction         
             FF1H      hourly average wind speed            
             FF24H     daily average wind speed             
             U1H       hourly average u wind component      
             U24H      daily average u wind component       
             V1H       hourly average v wind component      
             V24H      daily average v wind component       
             PCPTOTL   total precipitation                  
             PCP1H     accumulated precip - 1h              
             PCP24H    accumulated precip - 24h             
             PCPUDAY   accum. precip - user-defined day     
             UDSTART   user-defined day start HHMM          
             PCPRATE   precipitation rate                   
             T24MIN    24 hour minimum temperature          
             T24MAX    24 hour maximum temperature          
             SOILM2    soil moisture percent - 2 inch       
             SOILM4    soil moisture percent - 4 inch       
             SOILM8    soil moisture percent - 8 inch       
             SOILM20   soil moisture percent - 20 inch      
             SOILM40   soil moisture percent - 40 inch      
             SOILT2    soil temperature - 2 inch            
             SOILT4    soil temperature - 4 inch            
             SOILT8    soil temperature - 8 inch            
             SOILT20   soil temperature - 20 inch           
             SOILT40   soil temperature - 40 inch           
             DDMAX1H   wind dir at hourly max wind speed    
             FFMAX1H   hourly maximum wind speed            
             GSRD5M    global solar radiation - 5min        
             STNSPC1   station specific #1                  
             STNSPC2   station specific #2                  
             T24MINT   time of 24 hour minimum temperature  
             T24MAXT   time of 24 hour maximum temperature  
    
        Variables that have been added for COOP PLATTYP 2 stations:
    
             DDGUST    wind dir at gust  (5m)
             FFGUST    wind gust         (5m)
             PCP5M     accumulated precip - 5m              
    

  7. The user can select either accumulated precip - 1h or precipitation rate. Whichever variable is actually stored in the MADIS database will be converted to the form desired by the caller.
        OMO -- One Minute ASOS (listed as HFMETAR) PCP1H is an accum starting ~45 minutes after the hour until 44 minutes after the next hour.
    

  8. Precipitation intensity (MESONET):

           Value      Meaning
           -----      -------
             0        intensity info not available
             1        none
             2        light
             3        moderate
             4        heavy
             5        slight
             6        other
    

    Stations measuring precipitation type and intensity may take observations with one or two sensors. Therefore, an array of 2 elements will be returned for each record, and the caller should dimension the array to (2,200000).

  9. Precipitation type (MESONET):

           Value      Meaning
           -----      -------
             0        no precipitation
             1        precipitation present but unclassified
             2        rain
             3        snow
             4        mixed rain and snow
             5        light
             6        light freezing
             7        freezing rain
             8        sleet
             9        hail
            10        other
            11        unidentified
            12        unknown
            13        frozen
            14        ice pellets
            15        recent
            29        RPU-to-maxSensor communications failure
            30        sensor failure
    

    Stations measuring precipitation type and intensity may take observations with one or two sensors. Therefore, an array of 2 elements will be returned for each record, and the caller should dimension the array to (2,200000).

  10. The sky cover variables (METAR, SAO, MESONET, 1-minute ASOS) can have up to 6 different layers (array elements) for each record. The "sky cover layer base" variable is a number, so it should be dimensioned to (6,200000) by the caller. The character "sky cover" variable gives information about each layer reported in the sky cover layer base variable, and has 8 characters for each of the 6 layers, so it should be dimensioned character*8 skycover(6,200000). Note that the 1-minute ASOS dataset can only go up to 3 layers, but to allow for mixing its data with the other surface providers 6 layers (the last 3 always missing) will be returned.

    For more information on these variables, see section 9.4.2 of Federal Meteorological Handbook 1 (FMH-1). A PDF version of FMH-1 is available at https://www.ofcm.gov/fmh-1/fmh1.htm.

    Sky cover values:

           Value      Meaning               Summation amount of layer
           -----      -------               -------------------------
           VV         Vertical Visibility   8/8
           SKC or CLR Clear                 0
           FEW        Few                   1/8 - 2/8
           SCT        Scattered             3/8 - 4/8
           BKN        Broken                5/8 - 7/8
           OVC        Overcast              8/8
    
           1.  CLR is used at automated stations when no layers at or below 12,000 ft
               are reported; SKC is used at manual stations when no layers are 
               reported.
    
           2.  Any layer amount less than 1/8 is reported as FEW.
    

  11. Height of the lowest cloud layer (MARITIME):

           Value      Meaning
           -----      -------
             0        0 to 100 ft
             1        200 to 300 ft
             2        400 to 600 ft
             3        700 to 900 ft
             4        1000 to 1900 ft
             5        2000 to 3200 ft
             6        3300 to 4900 ft
             7        5000 to 6500 ft
             8        7000 to 8000 ft
             9        8500 or higher or no clouds
            -1        unknown or cloud base below surface of station
    

  12. Low level cloud type (MARITIME):

           Value      Meaning
           -----      -------
             0        no Cu, Cb, Sc, or St
             1        Cu w/ little vertical extent
             2        Cu w/ moderate or great vertical extent
             3        Cb w/out fibrous or striated upper part
             4        Sc formed by spreading Cu
             5        Sc not formed by spreading Cu
             6        St or ragged St
             7        ragged St or ragged Cu
             8        Cu and Sc w/ bases at different levels
             9        Cb w/ fibrous or striated upper part
            -1        low clouds not visible (obscured)
    

  13. Middle level cloud type (MARITIME):

           Value      Meaning
           -----      -------
             0        no Ac, As, or Ns
             1        semi-transparent As
             2        opaque As, or Ns
             3        semi-transparent Ac predominant
             4        Ac continually changing in appearance
             5        Ac invading the sky
             6        Ac formed by spreading of Cu or Cb
             7        double layered Ac or thick Ac; or Ac & As
             8        turreted Ac or Ac in tufts
             9        Ac of a chaotic sky
            -1        middle clouds not visible (obscured)
    
    

  14. High level cloud type (MARITIME):

           Value      Meaning
           -----      -------
             0        no Ci, Cs, or Cc
             1        Ci in filaments or hooks
             2        dense Ci & turreted Ci & Ci in tufts
             3        dense Ci orig from Cb, present
             4        Ci invading the sky
             5        Cs not exceeding 45 degrees altitude
             6        Cs exceeding 45 degrees altitude
             7        Cs covering the whole sky
             8        Cs not invading the sky
             9        Cc alone, or Cc more than (Ci & Cs)
            -1        high clouds not visible (obscured)
    

  15. Tide indicator (MARITIME):

           Value      Meaning
           -----      -------
             0        Data not available
             1        Low tide, observed tide below predicted level
             2        Low tide, observed tide same as predicted level
             3        Low tide, observed tide above predicted level
             4        Neither low nor high tide, observed tide below predicted level
             5        Neither low nor high tide, observed tide same as predicted level
             6        Neither low nor high tide, observed tide above predicted level
             7        High tide, observed tide below predicted level
             8        High tide, observed tide same as predicted level
             9        High tide, observed tide above predicted level
    

  16. The dewpoint & temperature from tenths of a deg C variables (METAR) are decoded from the remarks section of the raw reports, for designated stations only, and have values rounded to the nearest 0.1 degree C. The primary temperature and dewpoint variables are reported from all stations, and in the raw reports, are rounded to the nearest whole degree C.

  17. Road state (MESONET):

           Value      Meaning
           -----      -------
             0        No report
             1        Dry
             2        Moist
             3        Moist and chemically treated
             4        Wet
             5        Wet and chemically treated
             6        Ice
             7        Frost
             8        Snow
             9        Snow/Ice watch
            10        Snow/Ice warning
            11        Wet above freezing
            12        Wet below freezing
            13        Absorption
            14        Absorption at dewpoint
            15        Dew
            16        Black ice warning
            17        Other
            18        Slush
    

  18. Automated station type (METAR, SAO):

           Value      Meaning
           -----      -------
            AO1       automated station without precipitation discriminator (METAR)
            AO2       automated station with precipitation discriminator (METAR)
            AUTO2     automated station (SAO)
            AUTO4     automated station (SAO)
            AUTO7     automated station (SAO)
            AUTO8     automated station (SAO)
            blank     manual station
    

  19. Report type (METAR, SAO):

           Value      Meaning
           -----      -------
           METAR      scheduled report (METAR)
           SPECI      report triggered by SPECI criteria (METAR) (see FMH-1)
           SA         scheduled report (SAO)
    

  20. The coded values for the present weather variable (METAR, MARITIME) are too extensive to list in this document. See FMH-1, particularly section 12.6.8. A PDF version of FMH-1 is available at https://www.ofcm.gov/fmh-1/fmh1.htm.

    The coded values for the COOP present weather variable are listed below:

        
           Value      Meaning
           -----      -------
            -         No report
            FG        Fog
            IE        Ice
            GL        Glaze
            TS        Thunder
            GR        Hail
            DW        Damaging Winds
            RA        Rainy
            SN        Snowy
    

  21. The station location (METAR, MESONET, COOP) generally contains a geographic description of the station's location, typically including the city, state, and sometimes the country.

    With the MESONET dataset, in addition, characters (40:50) are used to denote the "subprovider", if any. Some (but not all) mesonets contain data from a number of smaller networks. In these cases, the "subprovider" for each station is the name of the smaller network. If this field is all blank, then there isn't a subprovider associated with the station. This information can also be obtained directly by reading the SUBPVDR variable, which only contains the subprovider designation.

    Note that the station location variable isn't available in the AWIPS database for METAR.

  22. The PCPUDAY (COOP) variable provides the accumulated precipitation for a 24 hour period that can be defined by each individual station. The UDSTART variable can be used to determine the start hour & minute of the "user-defined day". E.g., a UDSTART value of 1330 would mean the 24 hour accumulation period starts at 13:30 local time, a value of 200 would represent 02:00.

  23. The 1-minute ASOS Runway Visual Range (RVRID) is specified in degrees. The location of the RVR runway relative to other parallel runways (RVRLOC) is specified as follows:

           Value      Meaning
           -----      -------
           0          no runway parallel to RVR runway
           1          left
           2          center
           3          right
    

    The RVR distance type (RVRTYPE) variable has the following values:

           Value      Meaning
           -----      -------
           0          between highest and lowest reportable values
           1	  lowest reportable value
           2	  highest reportable value
    

  24. The 1-minute ASOS alert data bitmasks (ALERT1, ALERT2) provide an optional means to alert users to an operational value. This feature is optional, and may not be implemented on all stations. The tables below indicate the meaning of bits that may be set in the two words (LSB=1, MSB=16).

         ALERT1:
    
           Bit          Meaning
           ---          -------
           1            Sky Condition, In
           2            Ceiling, Up
           3            Ceiling, Down
           4            Visibility, Increase
           5            Visibility, Decrease
           6            Wind Direction/Preferred Runway Change
           7            Wind Speed, Increase
           8            Reserved
           9            Hail, Begin
           10           Hail, End
           11           Ice Pellets, Begin
           12           Ice Pellets, End
           13           Freezing Rain, Begin
           14           Freezing Rain, End
           15           Freezing Drizzle, Begin
           16           Freezing Drizzle, End
    
         ALERT2:
    
           Bit          Meaning
           ---          -------
           1            Thunderstorm, Begin
           2            Thunderstorm, End
           3            Thunderstorm, Increase
           4            Tornado Observed
           5            Funnel Cloud Observed
           6            Water Spout Observed
           7            Reserved
           8            Local Threshold Exceeded
           9            Snow, Begin
           10           Snow, End
           11           Rain, Begin
           12           Rain, End
           13           Non-specific Precip, Begin
           14           Non-specific Precip, End
           15           Fog, Begin
           16           Fog, End
    

  25. The COOP stations have the option to add up to two variables that are specific to the individual station.

  26. Commissioned status (COOP):

           Value      Meaning
           -----      -------
           0          commissioned             
           1          not yet commissioned
    

  27. Station quality indicator (COOP):

           Value      Meaning
           -----      -------
           [TBD]
    

  28. All times reported in the MADIS API are in Universal Coordinated Time, with the format of "YYJJJHHMM", where:

    YY = 2-digit year (good from 1980 - 2179)
    JJJ = Julian date of the year (1-366)
    HH = Hour (0-23)
    MM = Minute (0-59)

    If the max/min temperature time is missing, the 9-character field will be set to all blanks, e.g., " ". Users of the MADIS API sfcdump program will get the time output in their chosen format, either YYJJJHHMM or YYYYMMDD_HHMM.

  29. Some (but not all) mesonets, and the COOP dataset, contain data from a number of smaller networks. In these cases, the "subprovider" for each station is the name of the smaller network. If this variable is all blank, then there isn't a subprovider associated with the station.

  30. The total precipitation variable (COOP, MESONET, 1-minute ASOS) is an accumulation over a period of unknown duration. Stations that report this value will also report the PCP1H and PCP24H observations, except for 1-minute ASOS, which will report PCP1H but not PCP24H. The High Frequency total precipitation values are only available for AWOS stations. The PCPTOTL value is made available for those interested in calculating the accumulation over a period of other than 1 or 24 hours.

  31. The COOP door open/closed indicator is used to show when the instrument enclosure has been opened for maintenance.

           Value      Meaning
           -----      -------
             0        closed
             1        open
    

  32. The COOP rim heating on/off indicator is used to indicate when rim heating is on for the precipitation gauge.

           Value      Meaning
           -----      -------
             0        off
             1        on
    

  33. The stage 3 results from the 5m variables are also assigned to the 15m variables for UrbaNet.

  34. The 1-minute ASOS dataset contains the following "remarks" variables:

    Automated remarks status (ARMKST) is a bitmask with set bits indicating the detection of conditions triggering automated remarks (LSB=1, MSB=16):

           Bit          Meaning
           ---          -------
            1           variable visibility
            2           variable wind direction
            3	    variable ceiling
            4	    reserved
            5	    visibility at second location
            6	    ceiling height at second location
    
        Automated remarks (AUTORMK) encoding
        ------------------------------------
    
        Variable Visibility  
    
        The automated remark pertaining to variable visibility is
        expressed as: VSBY aaa(a)Vbbb(b), where aaa(a) and bbb(b) are 3-
        or 4-character, variable-length fields with leading "0" characters
        as necessary to ensure a 3 character minimum, and these represent
        range limits provided in hundredths of statute miles.  For
        example: VSBY 075V250 indicates a variation in visibility between
        0.75 and 2.5 miles.
    
        (ASOS/AOS Only) A multiple sensor visibility remark is inserted in
        this field in the exact format by which it is prepared for
        insertion as a multiple sensor visibility REMARK in METAR format.
        See FMH-1 for details of the formatting.
    
        Variable Wind
    
        The automated remark for variable wind direction is encoded as
        follows when the current average wind speed exceeds 6 knots: 
        WND ccVdd, where cc and dd are 2-character, fixed-length fields 
        with a leading "0" character as necessary, and indicates range
        limits provided in tens of degrees. For example: WND 06V13 denotes
        a variation in the true direction between 60 and 130 degrees.  
    
        The automated remark for variable wind direction is encoded as
        follows when the current average wind speed is equal to or less
        than 6 knots and five-second wind samples have varied over a range
        of 60 degrees or more over the past two minutes: VRBkkKT, where kk
        is a 2-character, fixed-length field with a leading "0" character,
        and "VRB" and "KT" shall be literals. For example: VRB03KT
    
        Variable Ceiling (ASOS/AOS Only)
    
        The automated remark for variable ceiling condition may indicate
        one (for an airport configured with a single cloud sensor) or one
        of two (for an airport configured with multiple cloud sensors)
        cloud conditions.  The format for the single cloud sensor
        configuration is: CIG eeeVfff, and the format for the multiple
        cloud sensor configuration is: 
    
        CIG eee gggggggg
        CIG eeeVfff
        CHINO gggggggg
    
        Upper case letters and blanks within individual remarks are
        fixed. Lower case eee,fff are 3-character, fixed-length fields
        with leading "0" character(s) as necessary, and respectively
        represent minimum and maximum ceiling heights, in hundreds of
        feet, above ground level (AGL).
    
        gggggggg is a 1- to 8-character, variable-length field
        representing one of the eight cardinal directions: "N", "NE", "E",
        "SE", "S", "SW", "W", "NW" and/or additional descriptors such as
        runway designators, etc.
    
        For example: CIG 008V020 indicates that a variable ceiling base
        height was detected between 800 and 2000 feet.
    
        Visibility At Second Location (ASOS/AOS Only) 
    
        The automated remark pertaining to visibility at a second
        location, generated only when this value is less than that
        registered at the primary location, is encoded as: 
        VIS aaaaa gggggggg, where aaaaa is a variable length field of up 
        to 5 characters representing the visibility in fractional format, 
        with a single space character separating the integer and fractional
        parts, and gggggggg is a 1- to 8-character, variable-length field
        representing one of the eight cardinal directions: "N", "NE", "E",
        "SE", "S", "SW", "W", "NW" and/or additional descriptors such as
        runway designators, etc. For example: VIS 1 3/4 RWY22 indicates a
        visibility of one and three quarters statute miles registered at
        the Runway 22 location.
    
        Ceiling Height At Second Location (ASOS/AOS Only) 
    
        The automated remark pertaining to ceiling height at a second
        location, generated only when this value is less than that
        registered at the primary location, is encoded as: 
        CIG hhh gggggggg, where hhh is a fixed length field of 3 characters
        representing the measured ceiling height in hundreds of feet, and
        gggggggg is a 1- to 8-character, variable-length field
        representing one of the eight cardinal directions: "N", "NE", "E",
        "SE", "S", "SW", "W", "NW" and/or additional descriptors such as
        runway designators, etc. For example: CIG 003 RWY22 indicates a
        ceiling height of three hundred feet registered at the Runway 22
        location.
    
        Operator remarks (OPERRMK) are free-formatted text.
    

  35. The 1-minute ASOS sensor status variables (DDSS, FFSS, FRZRSS, PCPASS, PCPTSS, PSS, RVRSS, SCLBSS, TDSS, TSS, VISSS) indicate the operational status of each sensor, as shown in the following table:

           Value      Meaning
           -----      -------
            0         Sensor operating/data available
            1         Reserved
            2         Sensor not installed
            3         Sensor out of service
            4         Reserved
            5         Sensors output in conflict
            6         Invalidated: Auto range check
            7         Invalidated: Auto rate of change
            8         Invalidated: Auto insufficent count
            9         Invalidated: By operator
            10        Data source offsite: Link failure
            11        Reserved
            12        Dewpoint sensor invalidated *
            13        Reserved
            14        Reserved
            15        Reserved
            16        Operator manual data entry
    
            * Value 12 is only used for the dewpoint sensor (TDSS).
    

  36. The 1-minute ASOS operating status (OPSTAT) is a bitmask indicating the status of the station as a whole, the meaning of the possible set bits (LSB=1, MSB=16) is shown below.

           Bit          Meaning
           ---          -------
            1           Operator on duty
            2           Test Mode
            3           Manual Mode
            4           Part or all data are suspect
    

  37. The 1-minute ASOS dataset parameter activation status (PARACT) pertains to obstructions to visibility and precipitation types. This is a bitmask, with set bits indicating that the associated parameters are active, i.e., being monitored (e.g. rain or snow), or determined by algorithm (e.g., haze, smoke). (LSB=1, MSB=16)

           Bit          Meaning
           ---          -------
            1           Mist monitoring active
            2           Fog monitoring active
            3           Ground fog monitoring active
            4           Ice fog monitoring active
            5           Haze monitoring active
            6           Smoke monitoring active
            7           Dust, volcanic ash monitoring active
            8           Blowing snow, sand monitoring active
            9           Rain monitoring active
            10          Snow grains monitoring active
            11          Freezing rain monitoring active
            12          Small hail and/or ice pellets monitoring active
            13          Ice pellets monitoring active
            14          Snow monitoring active
            15          Ice crystals monitoring active
            16          Hail monitoring active
    

  38. The road variable mobile head lights (HEDLIT) indicates whether the headlights are on or not.

           Value      Meaning
           -----      -------
            0         Not on
            1         On
    

  39. The road variable surface black ice signal (RDBIS) indicates if black ice is detected.

           Value      Meaning
           -----      -------
            0         Reserved
            1         Other
            2         No ice
            3         Black Ice
            4         Detector error
    

  40. The road variable visibility situation (VISSIT) describes visibility of travel environment.

           Value      Meaning
           -----      -------
            0         Reserved
            1         Other visibility anomaly
            2         Unknown
            3         Clear
            4         Fog - not patchy
            5         Patchy fog
            6         Blowing snow
            7         Smoke
            8         Sea spray
            9         Vehicle spray
            10        Blowing dust or sand
            11        Sun glare
            12        Swarms of insects
    

  41. The road variable mobile wipers (WIPER) indicates whether the wipers are on or not.

           Value      Meaning
           -----      -------
            0         Not on
            1         On
    

  42. The road variable precipitation Yes No (PCPYN) indicates if precipitation detected.

           Value      Meaning
           -----      -------
            0         Reserved
            1         Precip
            2         No Precip
            3         Error
    

    *The AWIPS database only has QC available for the MESONET dataset.


Notes - MADIS Radiometer Variables

  1. The radiometer dataset includes meteorological "profiles" from microwave radiometers. The station type variable is used to specify the type of radiometer that's in use, with these code values:
           Value      Meaning
           -----      -------
             0        Unspecified
             1        Radiometrics WVR-1100
             2        Radiometrics WVP-1500
             3        Radiometrics TP-2500
             4        Radiometrics TP/WVP-3000
             5        Radiometrics TP/WVP-3001
             6        Radiometrics TP/WVP-3002
             7        Radiometrics TP/WVP-3005
             8        Radiometrics TP/WVP-3006
    

    The number of levels (up to 100) and the heights of those levels may vary by the station type. Station types 1 through 4 all report 47 levels, from 0 to 1 km in 100 m steps, then from 1 km to 10 km in 250 m steps.

  2. Air temperature is the temperature variable stored in the database. The user can optionally select virtual temperature, which will then be calculated by the MADIS API. The QC results from air temperature will apply in either case. If virtual temperature cannot be calculated (missing or bad relative humidity), and the air temperature passed all QC checks, the air temperature will be returned instead, and a QC data descriptor value of "T" will be assigned. Also note that pressure is needed for the virtual temperature conversion; this is done by using the U.S. Standard Atmosphere calculation to calculate pressure from height.

  3. Relative humidity and absolute humidity are the moisture variables reported and stored in the database. The user can optionally select dewpoint temperature, dewpoint depression, specific humidity, or water vapor mixing ratio. These values will then be calculated by the MADIS API. The QC results from relative humidity will apply to any of the calculated variables. As with the virtual temperature conversion mentioned above, the specific humidity conversion uses pressure calculated from the heights. Also note that absolute humidity is sometimes referred to as "vapor density", these are in fact the same quantity.

  4. The true vertical coordinate is height. If the user selects pressure as the vertical coordinate, the heights are converted to pressure using the U.S. Standard Atmosphere calculation.

Last updated 31 October 2022