NOUS41 KWBC DDHHMM
PNSWSHTechnical Implementation Notice XX-XX
NOAA’s National Ocean Service Headquarters Washington DC
Related by National Weather Service Washington DCxxxx xM EDT xxx xxx xx 2011To:

Subscribers:-Family of Services-NOAA Weather Wire Service-Emergency Managers Weather Information Network-NOAAPORTOther NWS and NOS partners and NWS and NOS employees

From:Peter Stone
Chief, Oceanographic DivisionNOS Center for Operational Oceanographic Products andServices (CO-OPS)

Subject:

Implementation of National Ocean Service’s new
Oceanographic Forecast Modeling System for theDelaware Bay, Effective March 29, 2011

Effective March 29, 2011 beginning at 1500 Coordinated Universal
Time (UTC) (10AM EST), the NOAA/National Ocean Service Delaware
Bay Operational Forecast System (DBOFS) will be implemented
operationally on NOAA’s Central Computer System (CCS) operatedby NCEP Central Operations (NCO).
DBOFS provides users withnowcasts (analyses of near present) and forecast guidance of thethree-dimensional physical condition of the Delaware Bay,including 3-D water currents, water temperature, and salinity as
well as surface water levels out to 48 hours.
DBOFS uses as its core numerical ocean prediction model theRutgers University’s Regional Ocean Modeling System (ROMS), acommunity-based, free-surface, hydrostatic, primitive equation
ocean model which uses stretched, terrain-following sigma
coordinates in the vertical and curvilinear coordinates in thehorizontal. The DBOFS grid has 119 x 732 points in thehorizontal. The grid resolution in the x- and y- directions

ranges from 100m (328 feet) to 3km (1.86 miles). The verticalcoordinate system of ROMS follows the bathymetry and consists of
10 model sigma levels. The bathmetry used by DBOFS is based onNOS bathymetric data from the NOS/Office of Coast Survey’s
hydrographic surveys. The DBOFS grid domain was designed toinclude the entire Delaware Bay and a piece of the continental
shelf to allow a realistic interaction between the shelf and theentrance to the Bay.
DBOFS includes four daily nowcast and forecast cycles at 0, 6,12, and 18 UTC and operates within NOS’ Coastal Ocean Modeling
Framework (COMF). The DBOFS nowcast cyles use the previous 3-D
nowcast as its initial conditions along with meteorologicalforcing provided by hourly surface wind analyses from NCEP’s
Real-Time Mesoscale Analysis (RTMA) and surface heat flux fromNCEP’s North American Mesoscale (NAM) weather prediction model.
River discharge is estimated using near-real-time observations
from U.S. Geological Survey river gauges. Oceanographic
conditions on DBOFS’ lateral boundary on the shelf are estimatedbased on subtidal water level forecast guidance from NWS’ ExtraTropical Storm Surge (ETSS) Model and adjusted by observed
subtidal water levels at NOS water level gauges at Ocean City
Inlet, MD and Atlantic City, NJ,
tides from the Advanced
CIRCulation Model (ADCIRC) EC2001 tide database, and the U.S.
Navy’s Coastal Ocean Model (NCOM) water temperature and salinity
nowcasts.
The DBOFS forecast cycles use its latest 3-D nowcast as initialconditions, meteorological forcing provided by NCEP’s NAM model
forecast guidance, and river discharge estimated by persisting
the most recent observations for the entire forecast period. On
the lateral ocean boundary, forecast water levels are estimatedbased on subtidal water level forecast guidance from the NWS
ETSS Model and tides from the ADCIRC, while water temperatureand salinity conditions are based on NCOM forecast guidance.
Gridded and point forecast guidance from DBOFS will be available
in Network Common Data Form (netCDF) files on the NCEP server at
NOAA’s Web Operations Center(ftpprd.ncep.noaa.gov) in thedirectory/pub/data/nccfs/com/nos/prod/dbofs.yyyymmdd

At the NOS/CO-OPS OPeNDAP server
http://opendap.co-ops.nos.noaa.gov/netcdf/
and at the CO-OPS THREDDS server
http://opendap.co-ops.nos.noaa.gov/thredds/catalog.html.
DBOFS output is displayed on the CO-OPS web page
http://tidesandcurrents.noaa.gov/models.html
and the NOS nowCOAST web mapping portal athttp://nowcoast.noaa.gov.
Additional information about DBOFS can be found at
http://www.tidesandcurrents.noaa.gov/models.html.
DBOFS predictions are used by commercial and recreational
mariners and fishermen, emergency managers, search and rescue
operations, and NWS marine weather forecasters.
Thedevelopment and implementation of DBOFS was a joint project ofthe NOS/Office of Coast Survey/Coast Survey Development
Laboratory, the NOS/Center for Operational Oceanographic
Products and Services (CO-OPS), NWS/NCEP/NCO, and the ROMS
development group at Rutgers University. DBOFS is monitored 24x 7 by both NCO and CO-OPS’ Continuous Operational Real-Time
Monitoring System (CORMS) personnel.
If you have any questions concerning DBOFS,
Dr. Aijun Zhang
NOAA/NOS/CO-OPS
Silver Spring, MD 20910
Email: Aijun.Zhang@noaa.gov
orDr. Frank Aikman
Chief, Marine Modeling and Analysis Branch
Coast Survey Development Laboratory
NOAA/NOS/Office of Coast Survey
Silver Spring, MD 20910
Email: Frank.Aikman@noaa.gov

please contact:

For questions regarding the dataflow aspects with respect toNCEP server at the WOC, please contact:
Rebecca Cosgrove
NCEP/NCO Dataflow TeamCamp Springs, MD
Email: ncep.list.pmb-dataflow@noaa.govFor questions on how to access DBOFS digital products from COOPS servers please contact:
Rich Bourgerie
NOS/CO-OPS/Data Monitoring & Assessment Team
Silver Spring, MD 20910
Email: tide.predictions@noaa.gov