Submit a request

Articles in this section

See more

WGEN Weather Simulator

Avatar
Jason
  • Updated
Follow

WGEN is a stochastic weather generator originally developed in the 1980s in Fortran at the US Department of Agriculture Agricultural Research Service (Richardson and Wright 1984). It uses monthly and annual statistics to generate daily time series of precipitation, minimum temperature, maximum temperature, and solar radiation.

Use the WGEN PAR model to generate the parameter inputs for this model.

Experience Level:

Advanced

Download the Model File:

Tags:

  • rainfall
  • precipitation
  • hydrology
  • dashboard
  • weather
  • temperature
  • solar radiation
  • climate

Related articles

Comments

4 comments

Sort by Date Votes
  • Avatar
    Jason

    Model version 1.015 released on 4 Jan, 2019

    Version Report

    1. Added clarification to some element descriptions
    2. Changed the random number generator for determining wet/dry states in the Markov model from a Random Choice element to a stochastic with Uniform distribution.
    3. Added ability to override the random numbers with a user-defined value for the purposes of validation, if it is needed (so you can predict the outcome).
    1
    Permalink
  • Avatar
    Jason
    • Edited

    Model version 1.020 released on 11 Jan, 2019

    Version Report

    1. Corrected the label for observed rain, which was mislabeled as "observed radiation" and placed in the radiation portion of the inputs. This change doesn't affect the model output.
    2. Hard-code in deterministic values so that user only needs to turn it on or off to debug in deterministic mode
    3. Minor clarifications in documentation of temperature calculations
    4. Some textbooks define the scale factor for the gamma distribution differently. Some use the notation of lambda and this is 1/beta. Clarified in the documentation.
    1
    Permalink
  • Avatar
    Jason
    • Edited

    Model version 1.024 released on 25 Jan, 2019

    Version Report

    The harmonic value "x" in the temperature container should have an initial condition of vector(0) unless you are running it deterministically for verification purposes. This has been fixed using an IF statement: 

    if(Temp_Determ, vector(-0.3513, -1.754, 0.6244), vector(0))

    Where "Temp_Determ" is set to False by default. Only set this to True if you need to run a deterministic validation run.

    I was using a Random Choice element for determining the wet/dry state but it's not possible to use this if you want to switch to a deterministic run for validation. I rolled this back to an earlier version of the markov function that uses a stochastic with uniform distribution instead. This is how the FORTRAN code is implemented.

    1
    Permalink
  • Avatar
    Jason

    Model version 1.025 released on 7 Feb, 2019

    Version Report

    1. Fixed random number generator in markov rain model. The stochastic element used to generate random numbers in the rainfall container was not set to trigger daily. The trigger was added.
    1
    Permalink

Please sign in to leave a comment.