NCL Study Notes (weather analysis chart)

One, wind speed vector diagram

Let's look at a sample picture of wind and wind speed:

This is basically the same as the previous method of drawing the temperature map, the difference is

  Wres@vcrefmagnitudef          = 20.                ; Make vectors larger
  WRES@VCREFLENGTHF             = 0.030             ; Ref VEC length
  wres@vcglyphstyle             = " Windbarb "        ; Select wind Barbs
  WRES@VCMINDISTANCEF           = 0.025              ; Thin out Windbarbs
  Wres@vcwindbarbcolor      = 3
and the last called drawing function

Wplot = Gsn_csm_vector_map (wks,ddata1,vdata1,wres); Create plot

Ddata1 is the wind direction after interpolation, Vdata1 is the wind speed after interpolation

Since the wplot is to be superimposed with the previous map, the Overlayhas function is used, and finally the map after the overlay is displayed

Overlay (Map,wplot)
Draw (map)
Second, the surface meteorological elements of the weather analysis map

The image is plotted as a sample, not real data.

1. Each factor analysis icon

A string of 50char is required to display the icon on the left side of the graph, with the following data format:

Example

Imdat = "11721700181008020050300004983052026604007289086925"

A string (or array) of characters encoded as per the WMO/NOAA (World Meteorological Organization/United States National Oceanic and Atmospheric Administration) guidelines.
If an array, it must has the same shape as the x and Y arrays.
In more detail (where the characters is numbered from left to right, starting at character number 0):

Character 0 = ir-the precipitation Data indicator (hail index)
Character 1 = Ix-weather data and station type indicator (weather data and site Type index)
Character 2 = H-height above ground of base of lowest cloud
Characters 3-4 = vv-visibility in miles and fractions (visibility)
Character 5 = n-total amount of cloud cover (total cloud cover)
Characters 6-7 = Dd-direction from which winds is blowing (wind direction)
Characters 8-9 = Ff-wind speed in knots (air velocity)

If character = "1", then

character = Sn-sign of temperature
Characters 12-14 = ttt-current air temperature

If character = "2", then

character = Sn-sign of temperature
Characters 17-19 = Td-dew point

If character = "3", then

Characters 21-24 = po-station pressure (not plotted)

If character = "4", then

Characters 26-29 = Pppp-pressure reduced to sea level

If character = "5", then

character = A-characteristic of barograph
Characters 32-34 = Ppp-pressure, last 3 hrs.

If character = "6", then

Characters 36-38 = rrr-precipitation
Character = Tr-time duration of precipitation

If character = "7", then

Characters 41-42 = ww-present Weather
character = w1-most significant past weather
character = w2-2nd most sig. Past Weather

If character = "8", then

character = Nh-fraction of Sky cover
character = Cl-cloud type, low clouds
character = Cm-cloud type, medium clouds
character = Ch-cloud type, high clouds
The data can be converted to 50char according to the actual data, transmitted to

WMSTNM (Wks,lat_imdat,lon_imdat,imdat) to draw

2. Warm and cold peaks

WMSETP ("Fro", "warm"); Specify stationary front. Cold or warm or stationary (interal)
WMSETP ("CFC", 3); Use blue for the triangles.
WMSETP ("WFC", 2); Use red for the bumps.
WMSETP ("Swi", 0.02); Increase the size of the bumps and triangles.
WMSETP ("NMS", 2); Set the number of peaks
WMSETP ("Sig", 0.005)
WMSETP ("SLF", 0); 0 Using SL1 and SL2, 1 using SL1, 2 using SL2, 3 are not used, default value
WMSETP ("SL1", 90.) ; The angle between the starting direction and the X-axis
WMSETP ("SL2", 0.) ; The angle between the end direction and the X axis
Xlat = (/25., 30./); Latitudes.
Xlon = (/113., 116./); longitudes.
Wmdrft (wks, Xlat, Xlon)

3. Draw a high-pressure center

Take the high pressure as an example, with the red "D" represented.

Tres = True; Text Mods Desired
TRES@TXFONTHEIGHTF = 0.015; Make smaller
Tres@txfontcolor = 2; Red font

Gsn_text (Wks,map, "D", 123.,51.,tres)

Three, high-altitude meteorological elements Synoptic Analysis Map

   is the superposition of the isotherm and isobars, using the function map = Gsn_csm_contour_map_overlay (Wks,pdata,vdata,res,res2), and other terrestrial meteorological elements