WXP
User's Guide
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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.

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
obs observation (same as anal)
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
range (default)
avg average
acc accumulation
dif difference
max maximum
min minimum

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.

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.


Updated January 2021

plot_domain <<
forecast
>> level