METplus Practical Session Guide (July 2019) | MET Tool: MTD > MTD: Run

MTD: Run

First, we need to prepare our observations by putting 1-hourly StageII precipitation forecasts into 3-hourly buckets. Create an output directory:

Run the following PCP-Combine commands to prepare the observations:

Rather than listing 8 input forecast and observation files on the command line, we will write them to a file list first. Since the 0-hour forecast does not contain 3-hourly accumulated precip, we will exclude that from the list. We will use the 3-hourly APCP output from PCP-Combine that we prepared above:

Next, run the following MTD command:

Just as with MODE, MTD applies a convolution operation to smooth the data. However, there are two important differences. In MODE, the convolution shape is a circle (radius = conv_radius). In MTD, the convolution shape is a square (width = 2*conv_radius+1) and for time t, the values in that square are averaged for times t-1, t, and t+1. Convolving in space plus time enables MTD to identify more continuous space-time objects.

If your data has high enough time frequency that the features at one timestep overlap those at the next timestep, it may be well-suited for MTD.