Tropical cyclone track could be traced by locations of lowerest sea level pressure data. Here is an example: http://www.meteothink.org/examples/meteoinfolab/trajectory/typhoon_path_trace.html

Yaqiang Wang

Dear Professor Yaqiang Wang,

Thanks for your prompt reply,

I have checked metoinfomap, it is a great tool for visualizing WRF output.

As for cyclone tracking, Firstly I tried to use the ready NCL script but I received the following error :

fatal:Dimension sizes on right hand side of assignment do not match dimension sizes of left hand side

fatal:Execute: Error occurred at or near line 61 in file plot_ob_ascii_loc.ncl

NCL Script: https://www.ncl.ucar.edu/Applications/Scripts/WRF_track_1.ncl

For the code you attached, I am not good at programming therefore, I would like to ask you what is the code language (Fortran, Python,..) in order to run it.

Finally, I couldn't visualize the sea level pressure in both QGIS and Arc Map. In addition, I couldn't find it in the parameter panel in metoinfomap.

I attach my namelist.input in case of you need to check it.

Thanks in Advance

Sorry for late response. I am not a NCL user to help you on the problem of NCL. Sea surface level pressure (slp) is not included in WRF output file. It can be calculated from the existing variables in the file. I just update MeteoInfo to version 1.7a1 which include wrf module to get slp array from WRF output file. You can try the following MeteoInfoLab script to plot cycolone tracking.

fn = 'D:/Temp/nc/wrfout_d01_2005-08-28_00-00-00'

f = addfile(fn)

lat2d = f['XLAT'][0,:,:]

lon2d = f['XLONG'][0,:,:]

tt = f.gettimes()

tlat = []

tlon = []

press = []

for t in range(f.timenum()):

data = meteo.wrf.get_slp(f, timeidx=t)

idx = data.argmin()

idx = unravel_index(idx, data.shape)

tlat.append(lat2d[idx[0],idx[1]])

tlon.append(lon2d[idx[1],idx[1]])

press.append(data[idx[0],idx[1]])

#Plot

axesm(bgcolor=(204,255,255))

geoshow('country', edgecolor=[200,200,200], facecolor=(255,251,195))

plotm(tlon, tlat)

layer = scatterm(tlon, tlat, press)

colorbar(layer)

for t in range(0, f.timenum()):

text(tlon[t]+0.1, tlat[t], tt[t].strftime('%d:%H'))

#xlim(105, 120)

#ylim(15, 25)

title('Typoon path tracing')

The layer created from meteorological array can be ouput as a shape file which can be opened in QGIS or other GIS tools. Look at this example: http://www.meteothink.org/examples/meteoinfolab/file_io/write_shapefile.html .

Professor Yaqiang Wang ,

Thanks for your kind reply.

I will check it.

Best Regards.

Omar