Plots a hodograph of upper-air data.
HODO station time day [keywords]
controls display of sounding/parcel analysis values in the text frame and graphics frame; specify YES in text to list all the values in the text frame; specify YES in gra to plot selected values in the graphics frame below the hodograph; specify NO in either or both to suppress the values (default=NO YES)
source ADDE point dataset names for mandatory- and significant-level data; specify as group/descriptor or alias; you must specify NONE in the sig parameter or SIG=NO keyword to use only mandatory data, i.e., ignore the significant data (mand default=RTPTSRC/UPPERMAND; sig default=RTPTSRC/UPPERSIG if mand =RTPTSRC/UPPERMAND, otherwise sig default=NONE)
units for wind speed circles; run CU LIST to list the valid units and abbreviations (default=KTS)
HODO automatically erases the graphics before plotting the data.
A hodograph is a profile of a wind sounding representing the changing wind shear with height. Wind direction is the azimuth from the origin and wind speed is the radial distance from the origin. Northerly winds are plotted below the origin, and westerly winds are plotted to the right of the origin. The curve, or hodogram, between any two plotted points gives the wind shear between the two levels.
The table to the left of the wind speed circles lists pressure, height, wind speed and wind direction. The table includes all mandatory levels, plus significant wind and pressure levels whose pressure difference (from the adjacent levels in the table) is at least 30 mb.
Use the ANA keyword to list all available sounding/parcel analysis values in the text frame and plot selected values in the graphics frame below the diagram. To obtain the sounding/parcel analysis values, the reported heights are recomputed for hydrostatic consistency, though the adjustments are generally less than 10 meters. Also, the computed parcel temperature of a 12 UTC sounding is warmed 2 K to account for daytime heating. No adjustment is made to the computed parcel temperature of a 0 UTC sounding.
The following abbreviations are used for the sounding/parcel analysis values below the diagram: KI=K Index, LI=Lifted Index, SwI=Sweat Index, TTI=Total Totals Index, CVT=Convective Temperature in C, FMAX=Forecast Maximum Temperature in C, ThE=Equivalent Potential Temperature in K, EL=Equilibrium Level in mb, MIX=Mixing Ratio in g/kg, PW=Precipitable Water in mm, CAPE=Convective Available Potential Energy in J/kg, and HELI=Helicity in m**2/s**2. See Appendix E, Stability Parameters for definitions of these parameters.
This entry plots a blank hodograph without data from any station.
HODO KOUN 0
This entry plots a hodograph of mandatory- and significant-level data for Norman, Oklahoma at 0 UTC of the current day. The sounding table to the left of the hodograph lists pressure, height, wind speed and wind direction at each level. Note that you can also specify the station using Norman's 5-digit station ID number, 72357.
HODO KEYW 12 PRANGE=400 1000 INT=10 UNIT=MPH ANA=YES
This entry plots a hodograph of mandatory- and significant-level data for Key West, Florida at 12 UTC of the current day. Only winds between 1000 and 400 mb are plotted. Since there are only five wind speed circles and an interval of 10 miles per hour was specified with the INT and UNIT keywords, the circles represent 10, 20, 30, 40 and 50 MPH winds respectively. The ANA=YES keyword outputs all parcel/sounding analysis values in the text frame and selected values below the hodograph in the graphics frame.
HODO KMFR 12 06/JUNE/1998 DATASET=LOCAL/MAND.1017
This entry plots a hodograph of mandatory-level data for Medford, Oregon at 12 UTC on 6 June 1998. The data is obtained from the file in position 1017 of the dataset LOCAL/MAND.