Forecast Times
When a program involves viewing forecast information, the ability to determine the forecast time is necessary. This value can also be set with the time resource.
Menu
This menu lists possible forecast times. Since WXP does not make any assumptions as to what forecast times are available, this menu represents potential values of which some might not be valid for a particular model.
Forecast Time Menu 1: Initialized 14: 4.5 day 2: 6 hour 15: 5 day 3: 12 hour 16: 5.5 day 4: 18 hour 17: 6 day 5: 24 hour 18: 6.5 day 6: 30 hour 19: 7 day 7: 36 hour 20: 7.5 day 8: 42 hour 21: 8 day 9: 48 hour 22: 8.5 day 10: 60 hour 23: 9 day 11: 3 day 24: 9.5 day 12: 3.5 day 25: 10 day 13: 4 day 0: Back to previous menu -1: Exit program Enter the time:
The items in the time menu can be changed with the ".tim" menu files. This will allow you to set appropriate menu items based on model type.
Specifying Forecast Times
There are several ways to specify the forecast time in addition to above menu values. The syntax is:
time[-range][type]
You can specify a time by using entering the time and its units:
| Value | Description |
| init | Initial time |
| anal | analysis |
| 12hr | 12 hour forecast |
| h12 | 12 hour forecast |
| 2day | 2 day forecast |
| d2 | 2 day forecast |
| 4.5day | 4 1/2 day forecast |
| e4 | 4 1/2 day forecast |
| time | use the value of the time resource (useful in var files) |
| miss | missing value, take first available |
The range is an hour range that is followed by the type of range. The types of ranges are:
| Value | Description |
| rng | range |
| avg | average |
| acc | accumulation |
| dif | difference |
This leads to several possible combinations:
| Value | Description |
| anal-12acc | 12 hour accumulation up to analysis time or 12 hour observed accumulation. |
| anal-24dif | 24 hour difference between current and previous 24 hours. |
| 24hr-12acc | 12 hour accumulation up to the 24 hour forecast time. |
| time-12acc | 12 hour accumulation up to time specified in time resource (used in var files). |
Forecast Times and GRIB Data
Often gridded model data is specified with a complex time. The time and range syntax is a way of solving the problem of accessing these grids. A simpler way is to specify only the valid time.
-ft=24hr
-ft=24hr-12acc
The GRIB search algorithm will find the first grid with that valid time. The more verbose method will also work if there is more than one grid matching the same valid time.
Last updated June 1, 1998