NOUS41 KWBC 181244

PNSWSH

 

Technical Implementation Notice 13-41

NOAA’s National Ocean Service Headquarters Washington DC

Related by National Weather Service Washington DC

745 AM EST Mon Nov 18 2013

 

To:       Subscribers:

          -Family of Services

          -NOAA Weather Wire Service

          -Emergency Managers Weather Information Network

          -NOAAPORT

          Other NWS and NOS partners and NWS and NOS employees

 

From:     Peter Stone

          Chief, Oceanographic Division

          NOS Center for Operational Oceanographic Products

            and Services (CO-OPS)

 

Subject:  Implementation of National Ocean Service’s new

          Oceanographic Forecast Modeling System for the San

          Francisco Bay, Effective January 28, 2014

 

Effective January 28, 2014 beginning at 15z Coordinated Universal

Time (UTC), 10:00 AM EST, the NOAA/National Ocean Service San

Francisco Bay Operational Forecast System (SFBOFS) will be

implemented on NOAA’s Weather Climate Operational Supercomputing

System (WCOSS) operated by NCEP Central Operations (NCO). SFBOFS

will now provide users with nowcasts (analyses of near present)

and forecast guidance of the three-dimensional physical

conditions of the San Francisco Bay, including surface water

levels and 3-D water currents, water temperature, and salinity

out to 48 hours.

 

As its core ocean prediction model, SFBOFS uses the Finite Volume

Coastal 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, 3-D primitive equation coastal ocean model.

It has a horizontal grid comprised of unstructured triangular

cells in which the irregular bottom is presented using

generalized terrain-following coordinates.

 

The SFBOFS grid consists of 54,120 nodes and 102,264 elements and

includes the near shelf from Point Reyes (north) to Point San

Pedro (south), the entrance of San Francisco Bay, and the

complete bay system (Suisin Bay, San Pablo Bay and Central and

South Bays). Grid resolution ranges from 39 km near the offshore

open ocean boundary to approximately 100 m near the coast,

indicating the flexibility of the grid size based on bathymetry

from the deep ocean to the coast. Additionally, the higher

resolution along the navigational channels within the bays, from

approximately 100 m to 10 m, provides detailed current features.

 

SFBOFS operates within the NOS Coastal Ocean Modeling Framework

(COMF) and has four daily nowcast and forecast cycles at 03, 09,

15 and 21 UTC.

 

For the SFBOFS nowcast cycle, the meteorological forcing is

provided by the nested, high resolution (4 km) NCEP North

American Mesoscale (NAM) weather prediction model. River

discharge and stage are estimated using near real-time

observations from U.S. Geological Survey river gauges.

Oceanographic conditions of subtidal water levels, water

temperature and salinity on the SFBOFS lateral open boundary on

the shelf are estimated based on forecast guidance from the

Global Real-Time Ocean Forecast System (G-RTOFS) and adjusted by

real-time observations at NOS water level gauges. Tides are

derived from a regional tidal model of the northeast Pacific

Ocean developed by Dr. Mike Foreman. The Navy’s Hybrid Coordinate

Ocean Model (HYCOM) and the NWS Extra-Tropical Storm Surge (ETSS)

Model are used as a backup if G-RTOFS is not available.

 

For the SFBOFS forecast cycle, the meteorological forcing is

provided by the nested, high resolution (4 km) NCEP North

American Mesoscale (NAM) weather prediction model. River

discharge and stage are estimated by persistence of the most

recent near real-time observations from U.S. Geological Survey

river gauges. Oceanographic conditions of subtidal water levels,

water temperature and salinity on the SFBOFS lateral open

boundary on the shelf are estimated based on forecast guidance

from G-RTOFS. Tides are derived from Dr. Foreman’s northeast

Pacific Ocean tidal model. The Navy’s HYCOM and the NWS Extra-

Tropical Storm Surge (ETSS) Model are used as a backup if G-RTOFS

is not available.

 

Gridded and point forecast guidance from SFBOFS will be available

in netCDF files on the NCEP server at NOAA’s Web Operations

Centers (WOC) (ftpprd.ncep.noaa.gov) in the directory

 

/pub/data/nccfs/com/nos/prod/sfbofs.yyyymmdd

 

at NOS/CO-OPS OPeNDAP server

 

http://opendap.co-ops.nos.noaa.gov/netcdf/

 

and at CO-OPS THREDDS server

 

http://opendap.co-ops.nos.noaa.gov/thredds/catalog.html

 

SFBOFS output is displayed on the CO-OPS web page at

 

http://tidesandcurrents.noaa.gov

 

Additional information about SFBOFS can be found at

 

http://www.tidesandcurrents.noaa.gov/models.html

 

 

SFBOFS predictions are used by commercial and recreational

mariners and fishermen, emergency managers, search and rescue

operations, and NWS marine weather forecasters. The development

and implementation of SFBOFS was a joint project of the

NOS/Office of Coast Survey (OCS), the NOS/Center for Operational

Oceanographic Products and Services (CO-OPS), NWS/NCEP/NCO, the

University of Massachusetts, Dartmouth, and the Woods Hole

Oceanographic Institution. SFBOFS is monitored 24x7 by both

NCO/NCEP and CO-OPS Continuous Real-Time Monitoring System

(CORMS) personnel.

 

If you have any questions concerning these changes, contact:

 

Dr. Aijun Zhang

NOS/CO-OPS

Silver Spring, MD

Email: Aijun.Zhang@noaa.gov

or

Dr. Frank Aikman

Marine Modeling and Analysis Branch

Coast Survey Development Laboratory

NOAA/NOS/Office of Coast Survey

Silver Spring, MD

Email: Frank.Aikman@noaa.gov

 

For questions regarding the dataflow aspects with respect to the

NCEP server at the WOC, please contact:

 

Rebecca Cosgrove

NCEP/NCO Dataflow Team

College Park, MD

Email: ncep.list.pmb-dataflow@noaa.gov

 

For questions on how to access SFBOFS digital products from CO-

OPS servers please contact:

NOS/CO-OPS/User Services Team

Silver Spring, MD

Email: tide.prediction@noaa.gov

 

NWS National Technical Implementation Notices are online at:

 

http://www.nws.noaa.gov/os/notif.htm

 

$$