An Operational Forecast System (OFS) consists of the automated integration of observing system data streams, hydrodynamic model predictions, product dissemination and continuous quality-control monitoring. State-of-the-art numerical hydrodynamic models driven by real-time data and meteorological, oceanographic, and/or river flow rate forecasts form the core of these end-to-end systems. The OFS perform nowcast and short-term (0 hr. - 48 hr.) forecast predictions of pertinent parameters (e.g., water levels, currents, salinity, temperature, waves) and disseminate them to users.
Nowcasts and forecasts are scientific predictions about the present and future states of water levels (and possibly currents and other relevant oceanographic variables, such as salinity and temperature) in a coastal area. These predictions rely on either observed data or forecasts from a numerical model. A nowcast incorporates recent (and often near real-time) observed meteorological, oceanographic, and/or river flow rate data. A nowcast covers the period of time from the recent past (e.g., the past few days) to the present, and it can make predictions for locations where observational data are not available. A forecast incorporates meteorological, oceanographic, and/or river flow rate forecasts and makes predictions for times where observational data will not be available. A forecast is usually initiated by the results of a nowcast.
The files are in NETCDF format. Both NOAA and NASA provide tools for accessing NETCDF files:
Panoply is an application from NASA that allows users to view and graph data that are contained in NETCDF files.
ncdump is a software library that can be used for extracting data from a NETCDF file. It is aimed at advanced users.
Other tools are also available here.
The OFS Forecast is stored in an Amazon S3 bucket in us-east-1 AWS region.
This bucket contains the ensemble forecast data organized by day.
You can use the AWS Command Line Interface to list a particular day in the bucket like this:
aws s3 ls
OFS stands for Operational Forecast System, see table below
YYYY = year,
MM = month,
DD = day
|OFS Code||Operational Forecast System||Forecast Horizon||Resolution|
|cbofs||Chesapeake Bay||48 hrs||50m - 3km|
|creofs||Columbia River Estuary||48 hrs||100m - 4km|
|dbofs||Delaware Bay||48 hrs||100m - 3km|
|glofs||Great Lakes||60 hrs||5 km|
|gomofs||Gulf of Maine||72 hrs||700 m|
|leofs||Lake Erie||120 hrs||400m - 4km|
|negofs||North Eastern Gulf of Mexico||48 hrs||45m - 2km|
|ngofs||Northern Gulf of Mexico||54 hrs||600m - 10km|
|nwgofs||North Western Gulf of Mexico||48 hrs||60m - 3.5km|
|sfbofs||San Francisco Bay||48 hrs||100m - 4km|
|tbofs||Tampa Bay||48 hrs||100m - 1.2km|
Construction of the path for particular OFS will access to the forecast data. To construct the path and filename substitute the following variables into the path templates below:
OFS is the
OFS Code from previous table
CC is the model run cycles, 00, 06, 12, 18 , or 03, 09, 15, 21 for nowcast and forecast runs
YYYY = year,
MM = month,
DD = day
HHH is forecast hour, i.e. 001 – 072, check the forecast horizon in previous table
|File Names||Format||File Type|
|nos.OFS.stations.nowcast.YYYYMMDD.tCCz.nc||Station nowcast file (NetCDF)||output|
|nos.OFS.stations.forecast.YYYYMMDD.tCCz.nc||Station forecast file (netCDF)||output|
|nos.OFS.fields.nHHH.YYYYMMDD.tCCz.nc||Field nowcast file (NetCDF)||output|
|nos.OFS.fields.fHHH.YYYYMMDD.tCCz.nc||Field forecast file (NetCDF)||output|
|nos.OFS.2ds.nHHH.YYYYMMDD.tCCz.nc||Surface layer 2D Field nowcast file (NetCDF)||output|
|nos.OFS.2ds.fHHH.YYYYMMDD.tCCz.nc||Surface layer 2D Field forecast file (NetCDF)||output|
|nos.OFS.met.nowcast.YYYYMMDD.tCCz.nc||Surface forcing nowcast file (NetCDF)||input|
|nos.OFS.hflux.nowcast.YYYYMMDD.tCCz.nc||Surface flux forcing nowcast file (NetCDF)||input|
|nos.OFS.met.forecast.YYYYMMDD.tCCz.nc||Surface forcing forecast file (NetCDF)||input|
|nos.OFS.hflux.forecast.YYYYMMDD.tCCz.nc||Surface flux forcing forecast file (NetCDF)||input|
|nos.OFS.obc.YYYYMMDD.tCCz.nc||Open boundary forcing file (NetCDF)||input|
|nos.OFS.clim.YYYYMMDD.tCCz.nc||Climate nudging file from global RTOFS||input|
|nos.OFS.river.YYYYMMDD.tCCz.nc||River forcing file (NetCF)||input|
|nos.OFS.init.nowcast.YYYYMMDD.tCCz.nc||Initial condition file (NetCDF)||input|
|nos.OFS.roms.tides.YYYYMMDD.tCCz.nc||Tidal forcing file (NetCDF)||input|
|nos.OFS.nowcast.YYYYMMDD.tCCz.in||Runtime input file for nowcast (text)||input|
|nos.OFS.forecast.YYYYMMDD.tCCz.in||Runtime input file for forecast (text)||input|
|nos.OFS.fields.nowcast.YYYYMMDD.tCCz.nc||3D field nowcast file (NetCDF)||output|
|nos.OFS.fields.forecast.YYYYMMDD.tCCz.nc||3D field forecast file (NetCDF)||output|
If you append the model run name onto the path you will get:
Special Case - Great Lakes
The GLOFS data, the Great Lakes, is not structured in the same way as the data is for the other OFS models. GLOFS is composed of the nowcasts and forecasts for the lakes Huron (lhofs), Michigan (lmofs), Ontario (loofs) and Superior (lsofs).
Where lOFS is lhofs, lmofs, loofs or lsofs and BB is 00, 06, 12 or 18.
Learn more about the Operational Forecast System models via the following link: