weather-CurrentConditions

Each WeatherReport component has a Current Conditions child component that contains a number of read-only status properties for up-to-date weather statistics, as well as sunrise and sunset time.
 NOTE: A WeatherReport’s “CurrentConditions” component includes an “Observed” property (in AX-3.7 and later), as a timestamp of when reported conditions were last observed (U.S. NWS providers only). If this time is more than two hours in the past, other Current data values are given status “stale”. 
Figure 10.   Current Conditions (property sheet)
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An iconic summary is also available, on the parent WeatherReport’s default Current Weather View.

A child Advisories container provides management of received weather advisories, for use in the station’s alarming subsystem, and an air quality view is also available.

Name Value Description
Status (Weather) read-only
Indicates the current weather condition. Typically {ok} if a connection was made. Other possible statuses include:

alarm — if a hazardous condition is imminent/detected in an NWS provider-issued advisory. If alarm, related information is also in properties Weather Summary and State.

fault — if the weather provider references an invalid weather station.

stale — if a weather update connection fails, or for a NwsWeatherProvider, if the reported observation time (Observation property) is more than 2 hours in the past. All other properties with status (Sundown, Temp, State, Humidity, and so on) also assume this stale status. The timeout for this “failed connection at update attempt” to a NWS provider is fixed at 15 seconds.

Last Update read-only
Displays the date and timestamp of the station’s last weather report update, in Baja AbsTime format.
Last Failed Write read-only date and time
Reports the last failed write.
Observed read-only
Displays the date and timestamp of when the NWS reported the observed values in the last update, in Baja AbsTime format.
Sunrise read-only
Displays the timestamp for sunrise, in Baja Time format.
Sunset read-only
Displays the timestamp for sunset, in Baja Time format.
Sundown read-only
Indicates if the sun is down (true) or up (false). This dynamically updates whenever current time matches the Sunrise and Sunset times.
Temp read-only
Displays the current temperature as a StatusNumeric value.
Weather Summary read-only
Summarizes the current weather conditions, as a StatusString value. This text string is evaluated and converted to a State enumerated value (next property). If CurrentConditions has an alarm status, this describes the alarm condition.
State read-only
Displays a StatusEnum value derived from the received weather summary text. Enumerations indicate hazardous conditions based on information received in provider-issued advisories.
Humidity read-only
Displays the current humidity reading as a StatusNumeric value.
Wind Direction read-only
Displays a StatusEnum value derived from received text.
Wind Speed read-only
Displays the current wind speed value, as a StatusNumeric.
Wind Gust read-only
Displays the reported wind gust speed (if available), as a StatusNumeric. Possibly “null” if not available.
Wind Chill read-only
Displays the wind chill as calculated by the framework using a NOAA formula, providing that the:
  • temperature is between -50 and 50 degrees F, and
  • wind speed is between 3 and 110 mph (and is specific to the NWS provider).

    Otherwise, this value is “null”. Note that humidity is also utilized.

This formula is at:

http://www.nws.noaa.gov/om/windchill/index.shtml
Pressure read-only
Displays the current barometric pressure as a StatusNumeric value.
Dew Point read-only
Current dew point reading, as a StatusNumeric value.
Heat Index read-only
Displays the heat index as calculated by using a NOAA formula based on:
  • temperature > 80 degrees F, and
  • dew point > 60 degrees F, and
  • humidity > 40% (and is specific to the NWS provider).

    Otherwise, this value is null.

This formula is at:

http://www.nws.noaa.gov/jkl/?n=heat_index_calculator
Visibility read-only
Displays a StatusNumeric value for the current visibility.
Ozone read-only
Displays the level of ozone in the air in parts per million (ppm) as a StatusNumeric value.
Particulate Matter read-only
Displays the level of particulate matter in the air in micrograms per cubic meter (ug/m^3), as a StatusNumeric value.
 NOTE:
  • Related to these last two properties, the CurrentConditions component also has a Current Air Quality View.
  • The WeatherService retrieves air quality metrics by connecting to a U.S. EPA (Environmental Protection Agency) server.
 

About weather State

The State value of CurrentConditions and any Forecast component is a status enumeration derived from received weather summary text, using a best effort approach.

 NOTE: This summary text appears in the CurrentConditions property sheet as the “Weather Summary” value. 

You can link from the State slot of CurrentConditions or a Forecast component to a StatusEnum type slot of a control point, if needed. Facets of a linked point should be set to the frozen range (EnumRange) of WeatherState in the weather module to capture all 28 possible states.

Figure 11.   WeatherState enumerations seen in Facets, range Enum dialog
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 NOTE: Some enumerations were added for hazardous weather conditions, as received in provider-issued watches, warnings, and advisories—for example: tsunami, tornado, flood, and so on. These are reflected in the State property of CurrentConditions only if its Status is alarm. 

About weather Wind Direction

The Wind Direction value of CurrentConditions is a status enumeration derived from received text. You can link from the Wind Direction slot to a StatusEnum type slot of a control point, if needed. Facets of a linked point should be set to the frozen range (EnumRange) of WindDirection in the weather module to capture all 8 possible states.

Figure 12.   WindDirection enumerations seen in Facets, range Enum dialog
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