Time and Meteorological Forecasts

At least two time dimensions are routinely used to specify our fundamental data - basically the start and end points of a forecast. Meteorologists naturally think of T+00 as the important start point and T+nn as the end-point of an nn hour or day forecast, because of the time-critical scheduled forecasting process.

The natural way of thinking for most _non_-expert users is that the T+nn 'end point' is the time of interest, and the 'start point' of T+00 is less important and is only a proxy measure of quality.

There are several other relevant times to qualify a forecast, such as actual time of issue of the T+nn forecast, or the validity period for using the forecast (both somewhere between T+00 and T+nn), or the time of the latest observational data incorporated into the forecast, called the data cut-off time (possibly before T+00).

This aspect of time has been addressed in the Met-Ocean Domain Working Group's WMS 1.3 Best Practice for TIME and ELEVATION.

-- PieroCampalani - 09 Apr 2013 (from Chris Little's email, 18 Mar 2013)