SMS:Holland Symmetrical/Asymmetrical

The PBL engine is developed and maintained by Oceanweather Inc. Distribution of the model itself is controlled by OWI and is not available for sale through Aquaveo.

Holland Symmetrical/Asymmetrical

Once there is built a storm path, define the storm's attributes at each node of the path. Enter the node attributes dialog by selecting the Select Feature Point tool and double-clicking anywhere in the coverage. This opens the Storm Track Node Attributes dialog. Whenever opening this dialog, all vertices in the storm path are converted to nodes automatically.

A second way to open the Node Attributes dialog is to use the Select Feature Point tool to select one or more nodes on the path. Then right-click and select "Node Attributes...". This will highlight those nodes in the dialog.

Fields colored blue and displayed by default are those that are required for the Wind Model (symmetric or asymmetric) selected in the Coverage Attributes dialog. The "Show all"/"Show only required" button can be used to show all the fields available, even those not used by ADCIRC or for the selected wind model. These are useful for book keeping and completeness, even though they typically do not affect calculations.

The Storm start time sets the starting time for the first node in the storm's path. Each node then defines an offset from this starting time in hours (see below). Year, month, day and hour are important, while minutes and seconds should be left at 0.

The fields in the spreadsheet more or less correspond directly to a field in the fort.22 file [2]:

Node Attributes for Holland Symmetrical (NWS =8)

• Lat and Lon: These define the latitude and longitude of the given node, in tenths of degrees (900 = 90 degrees). Edit these values directly from the dialog, or select the nodes with the Select Feature Point tool and edit their X and Y that way. In this dialog, values are always positive and N/S/E/W determines quadrant, whereas the main SMS interface uses negative numbers for South and East.
• Technique: ADCIRC recommends that this be set to ASYM when dealing with asymmetric storms
• Time offset: This field combined with the Storm start time above the spreadsheet determine the YYYYMMDDHH and TAU fields in the fort.22. This field is the offset (in hours) from the storm start time.
• Max sustained wind speed (kts)
• Minimum sea level pressure (mb)
• Radius of last closed isobar
• Radius of max winds (nm)

Node Attributes for Holland Asymmetrical (NWS =19)

• Lat and Lon: These define the latitude and longitude of the given node, in tenths of degrees (900 = 90 degrees). Edit these values directly from the dialog, or select the nodes with the Select Feature Point tool and edit their X and Y that way. In this dialog, values are always positive and N/S/E/W determines quadrant, whereas the main SMS interface uses negative numbers for South and East.
• TechNum/Minutes
• Technique: ADCIRC recommends that this be set to ASYM when dealing with asymmetric storms
• Time offset: This field combined with the Storm start time above the spreadsheet determine the YYYYMMDDHH and TAU fields in the fort.22. This field is the offset (in hours) from the storm start time.
• Max sustained wind speed (knots)
• Minimum sea level pressure (mb)
• Wind radius code: ADCIRC requires that this be full circle for symmetric, and northeast quadrant for asymmetric. This is fairly restrictive, but SMS can convert many of the other options to northeast quadrant automatically. A model check will warn if some of the selections cannot be converted without losing data.
• Wind Intensity (RAD, RAD1-4): Each node can store wind intensity and radii for the storm shape at 34, 50, 64 and 100 kts.
• Wave height radius 1–4 (nm)
• Radius 1–4 Rmax
• Pressure of last closed isobar
• Radius of max winds (nm)
• Storm direction (degrees)
• Storm speed (kts)
• Storm name
• Holland B