[gradsusr] 500 hpa & Jetstream

Chorley Weather weatherstu at chorleyweather.com
Mon Apr 27 10:04:47 EDT 2015


On 27-04-2015 14:41, Stephen McMillan wrote:
> Stuart,
> Use whatever timeseries (or timestep range) fits your needs.  What I
> sent you was just an example with six timesteps.  The point was that
> you need to change your timestep through a time loop, either by
> specifying the timestep (or time/date) as an argument for the
> variable, or by setting the timestep (or time/date) for each increment
> of time.
> 
> Stephen Mc
> 
> On Mon, Apr 27, 2015 at 9:06 AM, Chorley Weather
> <weatherstu at chorleyweather.com> wrote:
> 
>> On 27-04-2015 13 [1]:33, Stephen McMillan wrote:
>>> For the heights to change, you need to change the timestep.  The
>>> example you sent has t=5.  If, for example, you want it to vary
>> from
>>> timestep 5 to 10, you need t=5 on the first, t=6 on the second,
>> and so
>>> forth.  Here's a simple loop, using your sample script:
>>> 
>>> 'set lev 500'
>>> 
>>> t1=5;t2=10
>>> ts=t1
>>> while(ts<=t2);#start time loop'set gxout shaded'
>>> 'set csmooth on'
>>> 'set clevs 4920 4960 5000 5040 5080 5120 5160 5200 5240 5280 5320
>> 5360
>>> 5400 5440 5480 5520 5560 5600 5640 5680 5720 5760 5800 5840 5880
>> 5920
>>> 5960 6000 6040 6080 6120'
>>> 'set ccols 61  63  65  67  69  71  73  75  77  79  81 
>> 83 
>>> 85  87  89  18  20  22  24  26  28  30  32  34  36 
>> 38 
>>> 41  43  45  47  49  51'
>>> 
>>> 'd hgtprs(t='ts')'
>>> 
>>> 'define slp  = const((prmslmsl*0.01),0,-u)'
>>> 
>>> 'set gxout contour'
>>> 'set ccolor 0'
>>> 'set cthick 10'
>>> 'set cint 5'
>>> 'set clopts 0'
>>> 'set clab masked'
>>> 'd slp'
>>> ts=ts+1
>>> endwhile;#end time loop
>>> 'cbarn'
>>> 
>>> Stephen Mc
>>> 
>>> On Mon, Apr 27, 2015 at 8:08 AM, Chorley Weather
>>> <weatherstu at chorleyweather.com> wrote:
>>> 
>> 
>>>> On 26-04-2015 20 [1]:28, Stephen McMillan wrote:
>>>> 
>>>> Stuart,
>>>> It would help if you shared the portion of your script that you
>>>> used
>>>> to attempt doing the 500mb height charts. What is the snag? 
>> What
>>>> GrADS error are you getting?  What are you trying to get your
>> code
>>>> to
>>>> do?
>>>> 
>>>>  Whether you need to define them depends on how you're using
>>>> them. 
>>>> Following is a simple sample, assuming I've opened the gfs 0p25:
>>>> 
>>>> 'set lev 500'
>>>> 'set clevs 5160 5280 5400 5520 5640'
>>>> 'set ccols 9 4 11 3 7'
>>>> 'd hgtprs(t=5)'
>>>> 
>>>> You can also define it first...
>>>> 'define hgt500=hgtprs(t=5)'
>>>> 'd hgt500'
>>>> 
>>>> Stephen Mc
>>>> 
>>>> On Sun, Apr 26, 2015 at 9:53 AM, Chorley Weather
>>>> <weatherstu at chorleyweather.com> wrote:
>>>> 
>>>> Hi guys,
>>>> 
>>>> Still rather new to grads but have managed to create some good
>>>> charts running the GFS 0.25, however, I have hit a snag on the
>>>> 500mb
>>>> height chart. Ive scripted all the colour and shading, including
>>>> the
>>>> contour bar but the hgt500 code will not work. Does this need
>>>> defining and if so can someone please share the definition. Also
>>>> I'd
>>>> love a jet stream chart, however, I am also struggling with
>> that.
>>>> Any info would be much appreciated.  I've attached my precip &
>>>> rainfall chart to show I'm not completely without hope :)
>>>> 
>>>> Thanks in advance,
>>>> Stuart.
>>>> 
>>>> --
>>>> Chief Forecaster & Owner
>>>> _______________________________________________
>>>> gradsusr mailing list
>>>> gradsusr at gradsusr.org
>>>> http://gradsusr.org/mailman/listinfo/gradsusr [2] [2] [1]
>>>> 
>>>> Links:
>>>> ------
>>>> [1] http://gradsusr.org/mailman/listinfo/gradsusr [2] [2]
>>>> 
>>>> _______________________________________________
>>>> gradsusr mailing list
>>>> gradsusr at gradsusr.org
>>>> http://gradsusr.org/mailman/listinfo/gradsusr [2] [2]
>> 
>>>   Hi Stephen,
>>> 
>>>   Thank you very much for your help. The sample worked fine and I
>> have
>>> manged to create a chart including a pressure overlay. However,
>> the
>>> issue I now have is the heights don't change when I run the gfs
>> data.
>>> I still get the same heights but the pressure works fine. I've
>>> attached some of my script for you to view. Not sure what I'm
>> missing
>>> to make the heights run with the gfs data. All my other charts
>> work
>>> fine so I know the noaa/dods link is fine.
>>> 
>>>   'set lev 500'
>>>   'set gxout shaded'
>>>   'set csmooth on'
>>>   'set clevs 4920 4960 5000 5040 5080 5120 5160 5200 5240 5280
>> 5320
>>> 5360 5400 5440 5480 5520 5560 5600 5640 5680 5720 5760 5800 5840
>> 5880
>>> 5920 5960 6000 6040 6080 6120'
>>>   'set ccols 61  63  65  67  69  71  73  75  77  79 
>> 81 
>>> 83  85  87  89  18  20  22  24  26  28  30  32  34 
>> 36 
>>> 38  41  43  45  47  49  51'
>>> 
>>>   'd hgtprs(t=5)'
>>> 
>>>   'define slp  = const((prmslmsl*0.01),0,-u)'
>>> 
>>>   'set gxout contour'
>>>   'set ccolor 0'
>>>   'set cthick 10'
>>>   'set cint 5'
>>>   'set clopts 0'
>>>   'set clab masked'
>>>   'd slp'
>>> 
>>>   'cbarn'
>>> 
>>>   Regards,
>>>   Stuart
>>> 
>>>   --
>>>   Chief Forecaster & Owner
>>> _______________________________________________
>>>   gradsusr mailing list
>>>   gradsusr at gradsusr.org
>>>   http://gradsusr.org/mailman/listinfo/gradsusr [2] [2]
>>> 
>>> 
>>> 
>>> Links:
>>> ------
>>> [1] tel:26-04-2015%2020
>>> [2] http://gradsusr.org/mailman/listinfo/gradsusr [2]
>>> 
>>> _______________________________________________
>>> gradsusr mailing list
>>> gradsusr at gradsusr.org
>>> http://gradsusr.org/mailman/listinfo/gradsusr [2]
>> Hi Stephen,
>> 
>> Again many thanks for your assistance. The time series I have been
>> using
>> for all my charts is below. Would I need to change this?
>> 
>> function main(args)
>> 
>> * Parse the arguments: date, hour
>>    if (args = '')
>>    prompt 'Enter forecast date (example, 20110717) --> '
>>    pull date
>>    prompt 'Enter forecast hour (example, 00 or 06 or 12 or 18)
>> --> '
>>    pull hour
>>    else
>>    date = subwrd(args,1)
>>    hour  = subwrd(args,2)
>>    endif
>> 
>> 'reinit'
>> 'sdfopen
>> 
> http://nomads.ncep.noaa.gov:9090/dods/gfs_0p25/gfs'date'/gfs_0p25_'hour'z
>> [3]'
>> 
>> * Get info from the descriptor file
>> 'q ctlinfo'
>> _ctl = result
>> _undef = getctl(undef)
>> _tdef = getctl(tdef)
>> _zdef = getctl(zdef)
>> 
>> maps = 81
>> 
>> * Get the Time axis info
>> tsize = subwrd(_tdef,2)
>> _t1 = 1       ;* 2nd half of timeseries
>> _t2 = 45
>> tsize = _t2 - _t1 + 1
>> 'set t '_t1' '_t2
>> 'q dims'
>> times  = sublin(result,5)
>> _time1 = subwrd(times,6)
>> _time2 = subwrd(times,8)
>> _tdim = _time1' '_time2
>> 
>> tincr = subwrd(_tdef,5)
>> _tdef = 'tdef 'tsize' linear '_time1' 'tincr
>> 
>> huh = subwrd(_tdef,4)
>> 
>> Regards,
>> 
>> Stuart.
>> 
>> --
>> Chief Forecaster & Owner
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr [2]
> 
> 
> 
> Links:
> ------
> [1] tel:27-04-2015%2013
> [2] http://gradsusr.org/mailman/listinfo/gradsusr
> [3]
> http://nomads.ncep.noaa.gov:9090/dods/gfs_0p25/gfs&#39;date&#39;/gfs_0p25_&#39;hour&#39;z
> 
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
Hi Stephen,

I figured it out, my time series works fine, it was just conflicting 
with the *t5* that I didn't need (doh). As mentioned I'm pretty new to 
these scripts. Cheers for all the help Stephen, much appreciated.

regards,
Stuart.
-- 
Chief Forecaster & Owner


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