This document describes the stm-file format and its usage.

ABOUT

Background

The stm-file was developed to provide inputs on a 6-hourly basis rather than the hourly basis in the original trk-file format. This is because we typically have information about a hurricane every 6-hours, so SLOSH users do not have to manually interpolate the 1-hourly trk-file values.

Structure

The stm-file consists of 3 comment lines, 13 lines to describe the storm at 6-hourly locations, 4 lines to describe the time associated with the 9th point, and a final line to describe the initial water levels. The 13 storm description lines consist of lat, lon (positive west), delta pressure (mBar), and radius of maximum winds (RMW; statute miles). The delta pressure typically assumes an ambient pressure of 1012 mBar.

The format is a fixed Fortran format, so keep the lat in col 0-9, lon in 10-19, delta pressure in col 20-29, and RMW in col 30-39. Anything after col 39 is ignored.

Example

HUR   H U G O BEST TRK BY BRJ;   DATUMS= 2.1/2.1 FT
 DELTA-P = 76MB ; CAT 4 ; RMW= 13 ST. MI.;  NW/28MPH
CHARLESTON HARBOR
24.40     70.10     60.       30.
25.20     71.00     60.       30.
26.30     72.20     60.       30.
27.20     73.40     60.       30.
28.00     74.90     60.       30.
29.00     76.10     62.       27.
29.85     77.20     65.       25.
31.00     78.23     70.       19.                 T-6 22Z/21
32.76     79.81     75.       13.                 T-0 LANDFALL
35.08     81.22     40.       15.                 T+6 10Z/22
37.70     81.96     25.       20.
42.20     80.20     22.       20.
46.00     74.50     20.       20.
0000
20
SEP
1989
2.1  2.1    TIDAL ANOMALIES (FEET) IN- AND OUTSIDE BAY (PRESSURE HEAD).

USE STM-FILE

Convert to trk-file

In order to run a stm-file, it helps to first convert it to a trk-file, since the trk-file can be visualized in the SLOSH-Display-Program (SDP). To convert a stm-file to a trk-file do:

cd ~/slosh/sorc/stm2trk.cd
make install
../../exec/stm2trk.exe hugo.stm hugo.trk 46 70 82

Choose Basin

To run the trk-file you need a computational domain (e.g., basin). To choose the appropriate basin, you can: load the trk-file in the SLOSH-GUI; load the basins in the SLOSH-Display-Program; utilize Google Maps; guess based on the basin’s lat/lon; or other. To find nearby basins, it helps to know their geographical order, which can be seen in ../parm/bnt/sloshdsp.bnt.

Determine Start/Stop

The start/stop hr of the model run should be adjusted appropriately. In the stm2trk example above the start-hr was 46 and the stop-hr was 82. The easiest way to adjust those is to bring the trk-file into the SLOSH-GUI, load the basin and have it compute the range. It attempts to compute the time between 1-hr before tropical-storm force winds enter the basin to 1-hr after tropical-storm force winds leave the basin.

Run the model

The model can now be run via:

cd ~/slosh/dev
cp ~/slosh/sorc/stm2trk.cd/hugo.trk .
../exec/sloshDos -rootDir ../parm -basin hch2 -trk hugo.trk -rex hugo.rex \
      -env hugo.env -verbose 1 -f_tide VDEF -TideDatabase 2014

That should create hugo.rex and hugo.env files in ~/slosh/dev. Those can then be viewed in the SDP, or manipulated via the SLOSH-Utility-Programs “rexout” or “envutil” described in README.md.