Align_Grids

Overview

This procedure will align the time breaks of selected weather elements to match the time breaks of the individual grids of a "source" element. The main idea is to help minimize manual splitting and stretching of grids in the Grid Manager. If a grid to align does not exist, then it will be created from scratch. Therefore one use of this procedure could be to create default SnowAmt grids that match the time breaks of QPF grids. In general, you will want to edit the source element first creating the desired time breaks and then run this procedure to align other elements before editing them. For example, edit Wx, then run Align_Grids to line up the floating PoP grids with the Wx grids, then edit PoP.

The data from an element's original time breaks are transformed to the new time breaks using the following methods:

• Wx: "MaxTime" - uses original grid with the dominant temporal coverage in the new aligned time range.
• PoP: "Max" - Maximum value of all original grids in the new time range of the aligned grid.
• Sky: "Max" - Maximum value of all original grids in the new time range of the aligned grid.
• WindGust: "Max" - Maximum value of all original grids in the new time range of the aligned grid. NOTE: WindGust is always aligned to Wind grids.
• Wind: "TimeWtAverage" - Time weighted average value
• QPF: "Sum" - Summation of all grids
• SnowAmt: "Sum" - Summation of all grids
• IceAccum: "Sum, - Summation of all grids

The logic for the procedure is as follows:

1. The procedure first copies the element to align to a temporary element.
2. New grids for the element to align are created from scratch to match the time breaks of the source element's grids.
3. The grids in the temporary element are either fragmented (for rate based elements) or split to match the time breaks of the source element.
4. Finally, the values in the temporary grids are assigned back to the aligned grids ' using the getGrids method with the appropriate setting of the getGrids "mode" argument.