hurricanetranslationvel#

[Vt, VtAzmdir, VtTrigdir, distxy] = hurricanetranslationvel(xCenter, yCenter, dt, distCalcMethod, CalcMethod, dispout)

Description#

Calculate hurricane center translational (forward motion) velocity

Inputs#

xCenter

x (longitude) of hurricane center (track)

yCenter

y (latitude) of hurricane center (track)

dt=6*3600;
Time interval between pressure data points in (s)
National Hurricane Center reports data every 6 hours
distCalcMethod=’gc’;
Distance calculation method
‘cart’: Distances are calculated on cartesian coordinate
‘gc’: Distances are calculated on Great Circle based on Vincenty formula, Vincenty (1975)
Earth radius coonsidered as mean earth radius=6371000 m
CalcMethod=’backward’;
Calculation method
‘forward’: Calculate hurricane central pressure intensity change over time using forward difference method
If CalcMethod=’forward’; then last element is zero
‘backward’: Calculate hurricane central pressure intensity change over time using backward difference method
If CalcMethod=’backward’; then first element is zero
‘central’: Calculate hurricane central pressure intensity change over time using central difference method
If CalcMethod=’central’; then first and last elements are zero
dispout=’no’;

Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs#

Vt

Hurricane central translational velocity in (m/s)

VtAzmdir
Hurricane center velocity azimuth (bearing) direction in (Degree)
azimuth (bearing) direction which is measured clockwise from the north:
0 (degree): toward North, 90 (degree): toward East, 180 (degree): toward South, 270 (degree): toward West
VtTrigdir

Hurricane center velocity trigonometric direction in (Degree)

distxy

Distance between hurricane locations of hurricane center in (m)

Examples#

%Longitude of Hurricane Katrine best track
longtrack=[-75.1;-75.7;-76.2;-76.5;-76.9;-77.7;-78.4;-79.0;-79.6;-80.1;-80.3;-81.3;...
    -82.0;-82.6;-83.3;-84.0;-84.7;-85.3;-85.9;-86.7;-87.7;-88.6;-89.2;-89.6;...
    -89.6;-89.6;-89.6;-89.6;-89.1;-88.6;-88.0;-87.0;-85.3;-82.9];

%Latitude of Hurricane Katrine best track
lattrack=[23.1;23.4;23.8;24.5;25.4;26.0;26.1;26.2;26.2;26.0;25.9;25.4;...
    25.1;24.9;24.6;24.4;24.4;24.5;24.8;25.2;25.7;26.3;27.2;28.2;...
    29.3;29.5;30.2;31.1;32.6;34.1;35.6;37.0;38.6;40.1];

[Vt,VtAzmdir,VtTrigdir,distxy]=hurricanetranslationvel(longtrack,lattrack,6*3600,'gc','backward','yes');

References#

Data

  • www.nhc.noaa.gov/data/

  • www.nhc.noaa.gov/data/hurdat/hurdat2-format-nencpac.pdf

  • coast.noaa.gov/hurricanes

  • www.aoml.noaa.gov/hrd/data_sub/re_anal.html