[THREDDS #DBI-852054]: thredds nbm dataset
- Subject: [THREDDS #DBI-852054]: thredds nbm dataset
- Date: Wed, 16 Feb 2022 11:41:42 -0700
See inline below:
> At various times, two snow accumulation variables appear in the dataset.
> 1. Total_snowfall_surface_1_Hour_Accumulation (with Time coordinate
> 2. Total_snowfall_surface_Mixed_intervals_Accumulation (with Time
> coordinate time6)
> Neither of these variables is documented in the NCEP nbm documentation.
> 1. Exactly what data is represented in these variables?
I'm not sure why there was a separate hourly accumulation, but currently on the
mixed interval version is available. This is the standard snow accumulation
that is documented here:
> 2. How many hours does each variable cover in a dataset?
> 3. Which hourly runs produce which variables?
Here is NCEP's documentation for how many hours each variable extends to for
each forecast run--for what's distributed on NOAAPORT, which is what provides
the data we host on THREDDS:
> 4. What does time7 and time6 mean?
time6 means it was the 6th unique time coordinate identified by netcdf-java as
it scanned through the grib file; time7 is the 7th. These are just trying to
come up with unique dimension names given the diverse set of different times
(reference time and valid time) in the GRIB collection.
> 5. To always get the latest model run, what time range should I request?
If you use the "Best" dataset, as linked, you'll get a collection of the times
closest to the range requested, with the smallest forecast offset (e.g. 12 hour
vs. 96 hour)
> 6. What is the "stride"?
How big a step to take through the data. If your requested time range of 0-12
with hourly data, a request with a stride of 3 will give (0, 3, 6, 9, 12).
> 7. How would I select a previous model run?
Either manually find the appropriate run time that contains the data you need
from the full list here:
Or use the Full collection, and subset using the reftime for the forecast you
Hope this helps!
Ticket ID: DBI-852054
Department: Support THREDDS
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