NOUS41 KWBC 221235
PNSWSH
Service Change Notice 22-91
NOAA’s National Ocean Service Headquarters Silver Spring MD
Relayed by National Weather Service Headquarters Silver Spring MD
835 AM EDT Thu Sep 22 2022
To:

Subscribers:-NOAA Weather Wire Service-Emergency Managers Weather Information Network-NOAAPort
Other NWS and NOS Partners, Users and Employees

From:

Patrick Burke
Chief, Oceanographic Division
NOS/Center for Operational Oceanographic Products
and Services

Subject: NOS OFS Version Updates and Implementation of Upgraded
Oceanographic Forecast Modeling Systems for Lakes Superior and Ontario:
Effective October 25, 2022
Effective on or about October 25, 2022 beginning at 1800 Coordinated
Universal Time (UTC), NOAA/National Ocean Service’s (NOS’) framework of
Operational Forecast Systems (NOS OFS) will be updated to version 3.5.
With this update, the upgraded Lake Superior Operational Forecast System(LSOFS) and Lake Ontario Operational Forecast System (LOOFS) will be
implemented by the National Centers for Environmental Prediction (NCEP)
Central Operations (NCO). The development and implementation of LSOFS
and LOOFS is a joint project of the NOS/Center for Operational
Oceanographic Products and Services (CO-OPS), the NOS/Office of Coast
Survey (OCS), the OAR/Great Lake Environmental Research Laboratory(GLERL), the FVCOM development group at the University of Massachusetts,
Dartmouth and NCO. This NOS OFS version update will change the directory
structure on the NOAA Operational Model Archive and Distribution System(NOMADS)/ftpprd to com/nosofs from com/nos. The upgraded LOOFS and LSOFS
will replace the existing Princeton Ocean Model (POMGL) based LOOFS andLSOFS. The existing LOOFS and LSOFS will be retired and their outputs
will no longer be available after the upgraded LOOFS and LSOFS are
implemented into operations.
NOS OFS NOMADS/FTPPRD directory structure changes:
The code package of the NOS model will be updated to v3.5 from v3.4, andthe name of the overall directory structure will change. This updatewill change NOS directory structures on NOMADS/FTPPRD under the top-levelcom/ directory:
https://nomads.ncep.noaa.gov/pub/data/nccf/com
https://ftpprd.ncep.noaa.gov/data/nccf/com
ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com

The following changes will be observed:
nos/{ENV}/cbofs.YYYYMMDD -> nosofs/{ENV}/cbofs.YYYYMMDD
nos/{ENV}/ciofs.YYYYMMDD -> nosofs/{ENV}/ciofs.YYYYMMDD
nos/{ENV}/creofs.YYYYMMDD -> nosofs/{ENV}/creofs.YYYYMMDD
nos/{ENV}/dbofs.YYYYMMDD -> nosofs/{ENV}/dbofs.YYYYMMDD
nos/{ENV}/gomofs.YYYYMMDD -> nosofs/{ENV}/gomofs.YYYYMMDD
nos/{ENV}/leofs.YYYYMMDD -> nosofs/{ENV}/leofs.YYYYMMDD
nos/{ENV}/lmhofs.YYYYMMDD -> nosofs/{ENV}/lmhofs.YYYYMMDD
nos/{ENV}/ngofs2.YYYYMMDD -> nosofs/{ENV}/ngofs2.YYYYMMDD
nos/{ENV}/sfbofs.YYYYMMDD -> nosofs/{ENV}/sfbofs.YYYYMMDD
nos/{ENV}/tbofs.YYYYMMDD -> nosofs/{ENV}/tbofs.YYYYMMDD
nos/{ENV}/wcofs.YYYYMMDD -> nosofs/{ENV}/wcofs.YYYYMMDD
where ENV is “prod” and “v3.4” for nos/ and “prod” and “v3.5” for nosofs/
and YYYYMMDD is the forecast day.
Parallel data is available in the following locations:
https://nomads.ncep.noaa.gov/pub/data/nccf/com/nosofs/v3.5
https://nomads.ncep.noaa.gov/pub/data/nccf/com/nosofs/para
https://ftpprd.ncep.noaa.gov/data/nccf/com/nosofs/v3.5
https://ftpprd.ncep.noaa.gov/data/nccf/com/nosofs/para
ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/nosofs/v3.5
ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/nosofs/para
NOTE: The ftpprd link only works for FTP-enabled web browsers.
Existing output changes:
One station is added to both the Lake Michigan and Huron Operational
Forecast System (LMHOFS) and the Northern Gulf of Mexico Operational
Forecast System (NGOFS2) station output files. Therefore, there are now
48 stations/locations for LMHOFS and 293 stations/locations for NGOFS2.
The following ice related float variables are added to the Lake Erie
Operational Forecast System (LEOFS)and LMHOFS hourly fields files: aice,latent_heat_flux, long_wave, sensible_heat_flux, tsfc, uuice, vice andvvice.
The following float variables are added to the LEOFS forecast met andhflux forcing files: long_wave, short_wave, net_heat_flux andair_pressure.
The Tair (surface air temperature) variable is added to surface field
output files for the Gulf of Maine Operational Forecast System (GOMOFS)
and the West Coast Operational Forecast System (WCOFS).
Changes to the existing LOOFS and LSOFS:
The existing LOOFS and LSOFS will be retired after the upgraded LOOFS andLSOFS are implemented in operations. Accordingly, the following output
files will no longer be available on the CO-OPS THREDDS server,
https://opendap.co-ops.nos.noaa.gov/thredds/catalog.html and on NCEPNOMADS and FTPPRD Web services:https://nomads.ncep.noaa.gov/pub/data/nccf/com
https://ftpprd.ncep.noaa.gov/data/nccf/com
ftp://ftpprd.ncep.noaa.gov/pub/data/nccf/com/
Under directory structure:
glofs/prod/glofs.YYYYMMDD
glofs.loofs.fields.nowcast.YYYYMMDD.tCCz.nc
glofs.loofs.fields.forecast.YYYYMMDD.tCCz.nc
glofs.lsofs.fields.nowcast.YYYYMMDD.tCCz.nc
glofs.lsofs.fields.forecast.YYYYMMDD.tCCz.nc
glofs.loofs.stations.nowcast.YYYYMMDD.tCCz.nc
glofs.loofs.stations.forecast.YYYYMMDD.tCCz.nc
glofs.lsofs.stations.nowcast.YYYYMMDD.tCCz.nc
glofs.lsofs.stations.forecast.YYYYMMDD.tCCz.nc
glofs.loofs.corms.YYYYMMDD.tCCz.log
glofs.lsofs.corms.YYYYMMDD.tCCz.log
Where YYYY, MM, DD is year, month, day, CC is cycle (00, 06, 12, 18).
Information on the new LOOFS and LSOFS output is provided further below.
Meteorological forcing condition changes of forecast cycles for LEOFS and
LMHOFS:LEOFS and LMHOFS meteorological forcing conditions for forecast cycles
will switch to the hybrid HRRR and NDFD from NDFD for LEOFS and GFS for
LMHOFS. As a result, the meteorological forcing condition file for
LMHOFS is smaller because NDFD provides 6-hourly products after forecasthour 66. Note that the size of the meteorological forcing condition filefor LEOFS is still increased because of additional fields added, as
discussed earlier. HRRR forecasts from 00, 06, 12, 18 cycles are used
for forecast hours 00-48, and a hybrid of HRRR+NDFD products are used forforecast hours 48-120. As a result, the job start/launch time of theGreat Lake models must be after HRRR completion which is roughly 1:50,
7:50, 13:50, 19:50 UTC.
Delivery time changes for LEOFS, LMHOFS, LOOFS, and LSOFS:
The Great Lake OFS product delivery times will be delayed byapproximately 65 minutes for LEOFS and LMHOFS, approximately 100 minutes
for LOOFS, and approximately 120 minutes for LSOFS due to the dependence
on HRRR completion and LOOFS and LSOFS upgrades to FVCOM-based highresolution models. The new delivery completion times in UTC are: 2:20,
8:20, 14:20, and 20:20 for LEOFS; 2:45, 8:45, 14:45, and 20:45 for
LMHOFS; 2:35, 8:35, 14:35, and 20:35 for LOOFS; and 2:55, 8:55, 14:55,
and 20:55 for LSOFS. The four delivery completion times correspond to
00Z, 06Z, 12Z and 18Z model forecast cycles.
Upgraded LSOFS and LOOFS:LSOFS/LOOFS will provide users with nowcasts (analyses of near present)
and forecast guidance of the three-dimensional (3-D) physical conditionsof Lake Superior and Lake Ontario including surface water levels and 3-Dwater currents and water temperature, as well as ice concentration,
thickness and velocity out to 120 hours.

As its core ocean prediction model, LSOFS and LOOFS use the Finite Volume
Community Ocean Model (FVCOM) developed jointly by the University of
Massachusetts, Dartmouth and the Woods Hole Oceanographic Institution.
FVCOM is a prognostic, unstructured-grid, finite-volume, free-surface, 3D primitive equation coastal ocean model with a horizontal grid comprisedof unstructured triangular cells. The irregular bottom is presented
using generalized terrain-following coordinates. FVCOM ice sub-model isadapted from an unstructured grid variant of Los Alamos Sea Ice Model(UG-CICE), version 3.4. Some updates have been made to reflect changes
in the subsequent versions of CICE. Ice dynamics include ice motion anddeformation, and ice thermodynamics describe new ice formation, growthand melting.
FVCOM and CICE are community models for NOS hydrodynamic and ice forecast
systems. LSOFS and LOOFS operate within the NOS Coastal Ocean Modeling
Framework (COMF) and have four daily nowcast and forecast cycles at 00,
06, 12, and 18 UTC.
The unstructured model grid for LSOFS has 90,964 nodes and 174,015
elements, and for LOOFS has 34,395 nodes and 64,453 elements. The cellsize ranges from approximately 200 m to 2.5 km, with higher resolution
along the shoreline and coarser resolution in the open waters of bothlakes. The model has 21 vertical sigma levels.
The surface meteorological forcing for the nowcast cycles is provided byshort-term forecast guidance from NOAA’s hourly updated High-Resolution
Rapid Refresh (HRRR) atmospheric forecast modeling system using the
Coupled Ocean–Atmosphere Response Experiment (COARE2.6) flux algorithm.
Surface forcing for the forecast cycles is obtained from a combination of
HRRR forecast guidance for the first 48 hours and then from the NWS
National Digital Forecast Database (NDFD) forecasts from 49 to 120 hours.
The specification of water levels due to inflow from tributaries, outflow
from connecting channels, and over-lake precipitation and evaporation isprescribed to track low-frequency seasonal changes in the lake waterlevels. NWS National Water Model (NWM) analysis and predictions are usedfor LOOFS and LSOFS river forcing conditions for eight rivers for boththe nowcast and forecast cycles. Real-time river discharge observations
at U.S. Geological Survey river gauges are used as a backup in bothcycles when NWM predictions are not available. Unaccounted
inflow/outflow due to inflow from additional tributaries, runoff, andover-lake precipitation and evaporation is determined via FVCOM’s
precipitation and evaporation parameters. Artificial “precipitation” or“evaporation” is calculated from the difference between the modeled
spatially-averaged water level and the average of measured water level
over the previous five days at six stations for LSOFS and four stations
for LOOFS from CO-OPS’ National Water Level Observation Network (NWLON)
and Canadian water level observation system.
The temperature of waters flowing into Lakes Superior and Ontario were
specified at U.S. Geological Survey (USGS) station 04024000 (St. LouisRiver) in LSOFS and USGS station 0421964005 YNTN6 (Niagara River) in
LOOFS.

New LSOFS/LOOFS Product Outputs:
Gridded fields and station/point forecast guidance from LSOFS and LOOFS
will be available in NetCDF format on the CO-OPS THREDDS server.
http://opendap.co-ops.nos.noaa.gov/thredds/catalog.html
and on NCEP Web services under lsofs.YYYYMMDD and loofs.YYYYMMDD:
https://nomads.ncep.noaa.gov/pub/data/nccf/com/nosofs/prod/
https://www.ftpprd.ncep.noaa.gov/data/nccf/com/nosofs/prod/
ftp://www.ftpprd.ncep.noaa.gov/pub/data/nccf/com/nosofs/prod/
Where YYYYMMDD is year, month, and day.
LSOFS and LOOFS graphics output is displayed on the CO-OPS web page at:https://tidesandcurrents.noaa.gov/ofs/lsofs/lsofs.html andhttps://tidesandcurrents.noaa.gov/ofs/loofs/loofs.html.
LSOFS and LOOFS have two types of model output data where YYYYMMDD isyear, month, day; CC is forecast cycle (00, 06, 12, 18).
One is field/gridded data which include two- and three-dimensional
gridded data with hourly intervals:
nos.l[s|o]ofs.fields.nHHH.YYYYMMDD.tCCz.nc
where HHH is 000, 001, 002, ..., 006
nos.l[s|o]ofs.fields.fHHH.YYYYMMDD.tCCz.nc
where ’n’ and ’f’ are used in front of nowcast and forecast hours
respectively, HHH is 000, 001, 002, ..., 120.
The other is station/point output data with a 6-minute interval. Water
level, surface wind, water temperature, and water currents are thepreliminary output variables:
nos.l[s|o]ofs.stations.nowcast.YYYYMMDD.tCCz.nc
nos.l[s|o]ofs.stations.forecast.YYYYMMDD.tCCz.nc
Model Input Files:
Initial files for nowcast:nos.l[s|o]ofs.init.nowcast.YYYYMMDD.tCCz.nc
Surface meteorological forcing NetCDF files:
nos.l[s|o]ofs.met.nowcast.YYYYMMDD.tCCz.nc
nos.l[s|o]ofs.met.forecast.YYYYMMDD.tCCz.nc
nos.l[s|o]ofs.hflux.nowcast.YYYYMMDD.tCCz.nc
nos.l[s|o]ofs.hflux.forecast.YYYYMMDD.tCCz.nc
River forcing files:
nos.l[s|o]ofs.river.YYYYMMDD.tCCz.nc.tar
LSOFS/LOOFS runtime input files:
nos.l[s|o]ofs.nowcast.YYYYMMDD.tCCz.in

nos.l[s|o]ofs.forecast.YYYYMMDD.tCCz.in
LSOFS/LOOFS also include the following log files:
The corms log file is used for generating OFS status flags for NOS/CO-OPS
Continuous Operational Real-Time Monitoring System (CORMS)
nos.l[s|o]ofs.corms.YYYYMMDD.tCCz.log.
ROMS runtime log file:
nos.l[s|o]ofs.jlogfile.YYYYMMDD.tCCz.log
nos.l[s|o]ofs.nowcast.YYYYMMDD.tCCz.log
nos.l[s|o]ofs.forecast.YYYYMMDD.tCCz.log
Additional information about LSOFS and LOOFS will be available after
implementation into production at:https://tidesandcurrents.noaa.gov/ofs/lsofs/lsofs_info.html
https://tidesandcurrents.noaa.gov/ofs/loofs/loofs_info.html
LSOFS and LOOFS predictions are used by commercial, recreational
mariners, fishermen, emergency managers, search and rescue responders,and NWS marine weather forecasters. The development and implementationof LSOFS and LOOFS is a joint project of the CO-OPS, OCS, GLERL, NCO, andthe FVCOM development group at the University of Massachusetts,
Dartmouth. LSOFS and LOOFS are monitored 24 x 7 by both NCO/NCEP and COOPS Continuous Operating Real-time Management System (CORMS) personnel.
NCEP urges all users to ensure their decoders can handle changes incontent order and volume changes. These elements may change with future
NCEP model implementations. NCEP will make every attempt to alert users
to these changes before implementation.
As part of NCEP’s standard 30-day parallel testing, the new output
products will be available here:
https://nomads.ncep.noaa.gov/pub/data/nccf/com/nosofs/v3.5
Any questions, comments or requests regarding this implementation should
be directed to the contacts below. We will review any feedback anddecide whether to proceed.
If you have any questions concerning these changes, please contact:
Dr. Aijun Zhang
NOS/Center for Operational Oceanographic Products and Services
Silver Spring, MD
Email: aijun.zhang@noaa.gov
For questions regarding the dataflow aspects, please contact:
Anne Myckow
NCEP/NCO Dataflow Team Lead
College Park, MD
Email: ncep.pmb.dataflow@noaa.gov

National Service Change Notices are online at:https://www.weather.gov/notification/
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