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[GEMPAK #SYC-256075]: GEMPAK - CAPE, CIN, LI, SHOWALTER, ETC using GDPROF or NSHARP?

> Steve,
> 
> When attempting to use your advice, the following script gave the error: 
> [GDPROF -6] Input for GVCORD is invalid.


Evan,

The cause of the error message above is your GVCORD should be PRES for a PTYPE 
of SKEWT. 
But,it doesn't make sense to plot anything but TMPC and DWPC on a SKEWT.
Any other vertical plot would use PTYPE=log or lin. However, in this case,
CAPE will be defined from the single level of the input to the CAPE
function, so there is no need to try to create a vertical profile of the data.
You can use GDPOINT for a single point, or GDPLOT2
to display CAPE over an area of points.

Steve Chiswell
Unidata User SUpport


> 
> gdprof << EOF
> GPOINT=44.588;-69.622
> GDATTIM=050622/000000F000
> GVCORD=hght
> GFUNC=cape(pres@0%none,hght@0%none,tmpc@2%hagl,dwpc@2%hagl)
> GVECT=
> GDFILE=/storm/huge/emlowery/research/narr/2005/narr_a_221_20050622_0000_000.grid
> LINE=2//2
> MARKER=5//1.25
> BORDER=1
> PTYPE=skewt
> SCALE=0
> XAXIS=-40/40/10
> YAXIS=1000/100/100/;1
> WIND=bm6//2
> REFVEC=10
> WINPOS=1
> FILTER=no
> TITLE=1/3
> PANEL=0
> CLEAR=yes
> TEXT=1
> DEVICE=xw
> OUTPUT=t
> THTALN=8/3/1
> THTELN=23/1/1
> MIXRLN=16/10/2
> 
> So, I looked at GDINFO and changed the GFUNC command to the following:
> 
> GFUNC=cape(pres@2%hght,hght@2%hght,tmpc@2%hght,dwpc@2%hght)
> 
> I'm able to get CAPE and CINS.  Hopefully these are true values starting at 
> 2m above ground level.
> 
> Thanks,
> Evan
> 
> -----Original Message-----
> From: Unidata GEMPAK Support [mailto:address@hidden]
> Sent: Tuesday, August 07, 2007 10:06 PM
> To: address@hidden
> Cc: address@hidden
> Subject: [GEMPAK #SYC-256075]: GEMPAK - CAPE, CIN, LI, SHOWALTER, ETC using 
> GDPROF or NSHARP?
> 
> > Institution: Plymouth State University
> > Package Version: 5.9.4
> > Operating System: UNIX
> > Hardware Information: UNIX
> > Inquiry: Hello,
> >
> > Currently I'm doing a 10-year thunderstorm climatology of northern New 
> > England thunderstorms.  In this study, each thunderstorm identified 
> > (thousands) will need a NARR proximity sounding at varying lat/lons.  NARR 
> > .grb were succesfully converted to .grid using NAGRIB.  GDPROF only seems 
> > to calculate the stability indices (CTOT,VTOT,TOTL,KINX,SWET).  Is it 
> > possible to have GDPROF calculate additional indices such as CAPE, CIN, LI, 
> > SHOWALTER INDEX, 0-3km shear, 0-6km shear, BRN, BRN SHEAR, etc?  I was 
> > unable to find any clear documentation on this.
> 
> Evan,
> 
> The stability indicies that GEMPAK can calculate involve individual level 
> values
> such as 700mb temp, dwpt, 850 temp 500mb height etc.
> 
> I added two functions for grids available on pressure vertical coordinates:
> CAPE ( PRES, HGHT, TMPC, DWPC )
> CINS ( PRES, HGHT, TMPC, DWPC )
> 
> The values of these are the initial level of the parcel (can be surface, 
> boundary or
> other level). All pressure level grids will be read in so that the 
> positive/negative
> area can be computed from the parce versus the environment. These 
> calculations become
> slow on larger grids since every level has to be read in and evaluated.
> An example using commonly available grids would be:
> CAPE(PRES@0%none, HGHT@0%none, TMPC@2%HAGL, DWPC@2%hagl)
> 
> The 2m temp and dewpoint and surface pres and height grids are typically 
> available
> from NCEP models.
> 
> To do other calculations such as 0-3km shear, you can use the LYR_ functions
> since you will have to interpolate between normal pressure levels of grids to
> find the 3km level.
> 
> Steve Chiswell
> Unidata User Support
> 
> 
> >
> > NSHARP did successfully calculate these indices.  However, I was only able 
> > to manually ingest the data into NSHARP and manually output the data into a 
> > postscript file.  This study will require an automatic process and text 
> > output.
> >
> > Thanks in advance,
> > Evan Lowery
> >
> > Plymouth State University Grad Program
> >
> >
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: SYC-256075
> Department: Support GEMPAK
> Priority: High
> Status: Closed
> 
> 
> 


Ticket Details
===================
Ticket ID: SYC-256075
Department: Support GEMPAK
Priority: High
Status: Closed