Weather

Weather data are required in several places in a WAM setup. The primary use is to determine potential evapotranspiration through GLEAMS using monthly averages. These are average monthly values over the entire period of record, in other words for any given parameter, e.g., average minimum montly temperature, there is a single value for January, a single value for February, etc. In the Scenario_WAM.mdb database, there are two tables that pertain to this: "Weather_Type" and "Weather_Detail_Char". The Weather_Type table contains an ID for a weather station and an associated name, as well as the elevation (in meters), the latitude (degrees), and four other parameters "NEWT", "NEWR", "NEWW", and "NEWD".

There must be at least one entry for the weather station. Note, however, that only one station is used per scenario. Multiple stations may be used so that different scenarios have different station data.

The Weather_Detail_Char table holds the monthly averages. Each record is the average value for a give month, with the WeatherID value relating back to the ID of the station. The other values are the MonthID (1 = January, 2 = February, etc.) and average maximum and minimum temperatures (in degrees Celsius), average solar radiation (in Megajoules per square meter per day), average windspeed (km/day; multiply km/hour by 24), and dewpoint (also in degrees Celsius)

In addition, a time series of daily temperatures (in degrees Celsius) must be provided in the Weather_Temperature_Char table. If a full time series is available (e.g., from NOAA) that may be used, otherwise a cyclic repeating time series of average values may be used.