scientimate.hurricanetranslationvel#

Vt, VtAzmdir, VtTrigdir, distxy = scientimate.hurricanetranslationvel(xCenter, yCenter, dt=6*3600, distCalcMethod='gc', CalcMethod='backward', dispout='no')

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#

import scientimate as sm

#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=sm.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