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20020501: [Fwd: Re: 20020328: Calculation of CAPE from CD-ROM soundings]
- Subject: 20020501: [Fwd: Re: 20020328: Calculation of CAPE from CD-ROM soundings]
- Date: Wed, 01 May 2002 13:34:34 -0600
Matthew,
In your message previously, you were questioning CAPE values.
I looked at the DDC sounding for 960514/1200 and clearly
the CAPE from the surface will be 0. That is the value you will arrive
at in SNLIST or SNPROF if you do not change the default level/layer
values in STNDEX using the "!" options.
The GEMPAK STNDEX computation of CAPE does allow you to change the depth and
level of
parameters using the ! characters. In NSHARP which is a completely different
program, the "PARCEL" popup window has the default set to "most unstable
parcel". With such a strong surface based inversion, the most unstable
parcel is elevated to 750 mb or so. If you select surface, then you will
get a CAPV value of 0 as well. So, as mentioned before, the
values you were comparing were not comparable.
The example 2 for JAN looks like the text input for the
sounding (from the CDROM dump output) was erroneous.
Probably if you look at the raob dump out, you will see that there is something
that the fsltogem program I wrote that will read the data into a
GEMPAK file (expecting certain columns etc) was choking on. EG:
after importing from the FSL dump out to GEMPAK
> STID = JAN STNM = 72235 TIME = 960331/0000
> SLAT = 32.32 SLON = -90.07 SELV = 91.0
> STIM = 0
>
> HGHT PRES TMPC SPED DRCT UWND VWND
> 91.00 997.20 20.60 6.00 180.00 0.00 6.00
> 6.00 997.20 20.60 180.71 185.08 16.00 180.00
> 6.00 997.20 20.60 180.71 185.08 16.00 180.00
> 6.00 997.20 20.60 180.71 185.08 16.00 180.00
You see that the HGHT value goes to 6, but that is suspiciously the value
of the SPED in the previous line. Go back to the raw RAOB dump and see
what is different about the text file in this case. My CD set only goes from
1946 to 1992 (version 1.0 from August 1993). The fsltogem program
can be beefed up to look for bad formats....if you can provide me with examples.
Steve Chiswell
Unidata User Support
>From: "Matthew Menne" <address@hidden>
>Organization: National Climatic Data Center, NOAA
>Keywords: 200205011801.g41I1aa25653
>Steve,
>
>I was just checking in to see if you had any ideas about how to deal
>with the problem that I was having calculating CAPE and extracting winds
>for certain soundings. I sent an example a month or so ago where it
>looked like some spurious levels were present in the archived sounding.
>NSHARP seemed to handle the sounding while SNLIST did not.
>
>thanks,
>
>Matt
>
>-------- Original Message --------
>Subject: Re: 20020328: Calculation of CAPE from CD-ROM soundings
>Date: Fri, 29 Mar 2002 12:17:39 -0500
>From: "Matthew.Menne" <address@hidden>
>Organization: National Climatic Data Center, NOAA
>To: Unidata Support <address@hidden>
>References: <address@hidden>
>
>Steve,
>
>I'm sending a little more information on the sounding issue. I was
>looking into a
>problem that I am having extracting the winds at various heights and
>dumped all
>levels from SNLIST for that sounding and got different values than I got
>from
>NSHARP. I've list the output from SNLIST below for the same sounding
>that I sent
>yesterday. You'll notice that the second entry wasn't in the data that
>I sent
>previously. I get a similar listing on one of the dates where I get
>strange
>values for winds at variout heights. The output for both these cases
>follow as
>examples 1 & 2. I hope this helps a little. Thanks again.
>
>Matthew
>
>Example 1 follows:
>
> SNPARM = HGHT;PRES;TMPC;DWPC;SPED;DRCT
> STNPRM = CAPE
>
> STID = DDC STNM = 72451 TIME = 960514/1200
> SLAT = 37.77 SLON = -99.97 SELV = 791.0
> STIM = 1200
>
> CAPE = 0.00
>
> HGHT PRES TMPC DWPC SPED DRCT
> 791.00 921.50 12.80 12.80 8.00 160.00
> 100.00 1000.00 -9999.00 -9999.00 -9999.00 -9999.00
> 759.00 925.00 -9999.00 -9999.00 -9999.00 -9999.00
> 913.00 908.10 12.50 12.20 12.00 169.00
> 914.00 908.00 12.50 12.20 11.80 170.00
> 988.00 900.00 12.10 11.80 14.00 175.00
> 1033.00 895.20 11.90 11.60 16.00 177.00
> 1096.00 888.60 12.40 11.90 18.00 182.00
> 1212.00 876.40 14.90 14.30 18.00 187.00
> 1219.00 875.70 14.90 14.30 18.00 180.00
> 1472.00 850.00 14.60 14.00 19.00 198.00
> 1766.00 821.00 13.40 12.80 20.00 208.00
> 1827.00 815.10 12.50 11.90 20.00 210.00
> 1828.00 815.00 12.50 11.80 19.50 210.00
> 1857.00 812.20 12.10 9.80 20.00 211.00
> 1890.00 809.00 12.10 6.40 20.00 212.00
> 1961.00 802.20 12.40 4.40 20.00 215.00
> 1984.00 800.00 12.50 4.50 20.00 216.00
> 2133.00 786.00 13.00 4.60 20.10 220.00
> 2236.00 776.40 13.40 4.60 20.00 226.00
> 2339.00 766.90 13.60 -12.50 20.00 230.00
> 2438.00 757.90 14.00 -11.60 20.10 230.00
> 2477.00 754.40 14.10 -11.30 20.00 234.00
> 2527.00 750.00 14.10 -7.80 19.00 235.00
> 2573.00 745.90 14.30 -4.90 19.00 236.00
> 2743.00 730.90 13.00 -2.30 18.00 240.00
> 3105.00 700.00 10.10 3.20 14.00 239.00
> 3352.00 679.50 8.20 0.60 12.30 245.00
> 3393.00 676.10 7.90 0.20 12.00 246.00
> 3519.00 665.80 7.20 -3.90 12.00 251.00
> 3634.00 656.60 6.70 -15.90 12.00 255.00
> 3657.00 654.70 6.50 -16.00 11.80 255.00
> 3716.00 650.00 6.00 -16.40 12.00 258.00
> 4007.00 627.20 3.60 -18.40 13.00 269.00
> 4109.00 619.40 2.50 -12.40 14.00 273.00
> 4144.00 616.70 2.20 -13.50 14.00 274.00
> 4181.00 613.90 2.10 -20.30 14.00 275.00
> 4267.00 607.40 1.50 -21.10 15.40 275.00
> 4365.00 600.00 0.80 -22.10 16.00 278.00
> 4493.00 590.50 -0.10 -23.50 17.00 279.00
> 4572.00 584.70 -0.80 -23.40 17.00 280.00
> 4858.00 564.00 -3.40 -23.00 17.00 282.00
> 4876.00 562.70 -3.60 -22.70 16.50 280.00
> 5055.00 550.00 -5.20 -19.20 16.00 282.00
> 5364.00 528.70 -7.90 -16.40 14.00 281.00
> 5795.00 500.00 -11.90 -17.10 13.00 273.00
> 6096.00 480.60 -14.40 -18.80 14.40 270.00
> 6142.00 477.70 -14.80 -19.10 15.00 269.00
> 6222.00 472.70 -15.10 -19.40 15.00 268.00
> 6302.00 467.70 -15.10 -21.60 16.00 268.00
> 6400.00 461.60 -16.00 -22.20 15.90 270.00
> 6591.00 450.00 -17.70 -23.30 19.00 269.00
> 6828.00 436.00 -19.80 -24.60 20.00 270.00
> 7107.00 419.80 -21.80 -24.70 20.00 272.00
> 7461.00 400.00 -24.30 -29.20 18.00 276.00
> 7620.00 391.30 -25.70 -31.00 17.50 275.00
> 7918.00 375.50 -28.20 -34.50 18.00 276.00
> 8026.00 369.90 -29.00 -37.50 18.00 275.00
> 8326.00 354.60 -31.20 -41.50 18.00 276.00
> 8418.00 350.00 -31.80 -43.50 18.00 277.00
> 8708.00 335.90 -34.00 -52.60 19.00 280.00
> 9144.00 315.30 -38.00 -55.60 18.00 285.00
> 9448.00 301.70 -40.80 -57.70 16.50 295.00
> 9487.00 300.00 -41.20 -58.00 17.00 292.00
> 9842.00 284.60 -44.40 -60.70 16.00 288.00
> 10174.00 270.80 -46.50 -9999.00 13.00 279.00
> 10668.00 251.10 -50.90 -9999.00 12.30 265.00
> 10698.00 250.00 -51.20 -9999.00 13.00 264.00
> 11277.00 228.30 -55.50 -9999.00 16.50 260.00
> 11718.00 213.10 -58.70 -9999.00 14.00 270.00
> 11887.00 207.40 -59.60 -9999.00 13.90 280.00
> 12114.00 200.00 -60.70 -9999.00 14.00 283.00
> 12935.00 175.00 -65.40 -9999.00 19.00 282.00
> 13009.00 172.90 -65.80 -9999.00 19.00 281.00
> 13411.00 161.90 -64.90 -9999.00 21.60 280.00
> 13876.00 150.00 -63.90 -9999.00 22.00 286.00
> 14232.00 141.50 -64.00 -9999.00 21.00 292.00
> 14417.00 137.30 -63.40 -9999.00 22.00 297.00
> 14641.00 132.40 -61.40 -9999.00 21.00 300.00
> 14836.00 128.30 -60.70 -9999.00 21.00 302.00
> 14998.00 125.00 -60.70 -9999.00 21.00 305.00
> 15240.00 120.20 -60.90 -9999.00 20.60 305.00
> 15554.00 114.30 -61.20 -9999.00 19.00 310.00
> 15926.00 107.60 -63.60 -9999.00 20.00 310.00
> 16154.00 103.70 -63.40 -9999.00 20.10 310.00
> 16224.00 102.50 -63.40 -9999.00 20.00 312.00
> 16376.00 100.00 -62.50 -9999.00 20.00 312.00
> 16459.00 98.70 -62.40 -9999.00 19.50 310.00
> 16615.00 96.20 -62.10 -9999.00 20.00 313.00
> 16924.00 91.50 -63.60 -9999.00 19.00 316.00
> 17170.00 87.90 -63.20 -9999.00 18.00 318.00
> 17746.00 80.00 -65.30 -9999.00 16.00 322.00
> 17807.00 79.20 -65.50 -9999.00 16.00 323.00
> 17947.00 77.40 -64.80 -9999.00 15.00 326.00
> 18058.00 76.00 -65.50 -9999.00 14.00 326.00
> 18557.00 70.00 -65.80 -9999.00 13.00 328.00
> 19072.00 64.30 -66.70 -9999.00 12.00 332.00
> 19202.00 62.90 -65.30 -9999.00 11.80 335.00
> 19323.00 61.70 -64.00 -9999.00 11.00 336.00
> 19483.00 60.10 -64.80 -9999.00 11.00 342.00
> 19493.00 60.00 -64.80 -9999.00 11.00 342.00
> 19812.00 57.00 -63.30 -9999.00 7.20 360.00
> 19829.00 56.80 -63.20 -9999.00 7.00 360.00
> 19994.00 55.30 -61.20 -9999.00 6.00 1.00
> 20165.00 53.80 -61.70 -9999.00 5.00 2.00
> 20424.00 51.60 -59.50 -9999.00 5.00 2.00
> 20621.00 50.00 -60.20 -9999.00 4.00 5.00
> 20940.00 47.50 -61.50 -9999.00 5.00 2.00
> 21306.00 44.80 -57.10 -9999.00 5.00 7.00
> 21336.00 44.60 -57.10 -9999.00 5.10 10.00
> 21609.00 42.70 -57.60 -9999.00 4.00 6.00
> 22028.00 40.00 -51.70 -9999.00 2.00 315.00
> 22092.00 39.60 -50.90 -9999.00 2.00 305.00
> 23019.00 34.30 -54.70 -9999.00 1.00 284.00
> 23876.00 30.00 -54.20 -9999.00 3.00 27.00
> 24902.00 25.60 -50.20 -9999.00 5.00 44.00
> 25058.00 25.00 -48.70 -9999.00 4.00 56.00
> 25354.00 23.90 -45.90 -9999.00 4.00 92.00
> 26087.00 21.40 -47.20 -9999.00 4.00 141.00
> 26535.00 20.00 -46.60 -9999.00 2.00 150.00
> 27313.00 17.80 -43.50 -9999.00 2.00 38.00
> 27432.00 17.50 -44.00 -9999.00 1.50 45.00
> 27736.00 16.70 -45.50 -9999.00 2.60 60.00
> 27821.00 16.50 -45.90 -9999.00 3.00 60.00
> 28194.00 15.60 -45.10 -9999.00 -9999.00 -9999.00
>
>Example 2 follows:
>
> STID = JAN STNM = 72235 TIME = 960331/0000
> SLAT = 32.32 SLON = -90.07 SELV = 91.0
> STIM = 0
>
> HGHT PRES TMPC SPED DRCT UWND VWND
> 91.00 997.20 20.60 6.00 180.00 0.00 6.00
> 6.00 997.20 20.60 180.71 185.08 16.00 180.00
> 6.00 997.20 20.60 180.71 185.08 16.00 180.00
> 6.00 997.20 20.60 180.71 185.08 16.00 180.00
>
>(Note that the heights should be 91;1091;3091;6091 and they are for most
>other
>days)
>
>
> SNPARM = HGHT;PRES;TMPC;DWPC;SPED;DRCT
> STNPRM = CAPE
>
> STID = JAN STNM = 72235 TIME = 960331/0000
> SLAT = 32.32 SLON = -90.07 SELV = 91.0
> STIM = 0
>
> CAPE = -9999.00
>
> HGHT PRES TMPC DWPC SPED DRCT
> 91.00 997.20 20.60 16.00 6.00 180.00
> 11582.00 -9999.00 -9999.00 -9999.00 39.60 265.00
> 66.00 1000.00 -9999.00 -9999.00 -9999.00 -9999.00
> 118.00 994.10 20.60 15.20 6.00 179.00
> 304.00 972.80 18.80 15.30 6.70 170.00
> 491.00 951.90 17.00 15.50 6.00 159.00
> 508.00 950.00 16.80 15.30 6.00 158.00
> 609.00 938.80 16.20 14.80 5.70 150.00
> 736.00 925.00 15.40 14.10 5.00 148.00
> 914.00 905.80 14.00 13.10 4.60 150.00
> 922.00 904.90 13.90 13.10 5.00 149.00
> 950.00 901.90 14.30 13.00 5.00 151.00
> 968.00 900.00 14.50 12.00 5.00 152.00
> 1006.00 896.00 15.00 9.40 5.00 155.00
> 1058.00 890.50 15.00 6.30 5.00 158.00
> 1162.00 879.60 14.80 5.30 5.00 165.00
> 1219.00 873.70 14.40 5.90 5.10 170.00
> 1451.00 850.00 12.60 8.30 6.00 182.00
> 1524.00 842.60 12.40 7.30 6.20 180.00
> 1629.00 832.10 12.10 5.90 7.00 195.00
> 1828.00 812.60 12.00 1.30 8.20 210.00
> 1924.00 803.30 11.90 -0.90 9.00 221.00
> 1959.00 800.00 12.00 -3.30 9.00 223.00
> 2007.00 795.40 12.10 -8.30 9.00 226.00
> 2088.00 787.70 12.00 -12.20 10.00 231.00
> 2133.00 783.50 11.70 -12.50 10.30 235.00
> 2438.00 755.20 9.40 -14.90 13.40 250.00
> 2496.00 750.00 9.00 -15.40 13.00 250.00
> 2585.00 742.00 8.30 -16.00 14.00 251.00
> 2743.00 727.80 7.20 -11.20 15.40 255.00
> 2826.00 720.60 6.70 -8.80 16.00 253.00
> 3062.00 700.00 4.50 -10.70 17.00 251.00
> 3193.00 688.80 3.40 -10.50 18.00 251.00
> 3282.00 681.30 2.70 -8.00 19.00 252.00
> 3394.00 671.90 1.80 -10.90 20.00 252.00
> 3534.00 660.30 0.60 -9.90 21.00 251.00
> 3621.00 653.20 0.10 -11.80 21.00 251.00
> 3657.00 650.20 -0.30 -11.60 21.10 250.00
> 3660.00 650.00 -0.30 -11.60 21.00 251.00
> 3855.00 634.30 -2.00 -10.20 22.00 251.00
> 3941.00 627.50 -2.70 -11.60 22.00 251.00
> 4073.00 617.10 -3.40 -19.60 22.00 252.00
> 4128.00 612.80 -3.70 -21.20 22.00 253.00
> 4267.00 602.10 -4.80 -20.40 22.60 255.00
> 4294.00 600.00 -5.00 -20.20 23.00 255.00
> 4595.00 577.40 -7.50 -19.30 25.00 260.00
> 4876.00 556.70 -10.20 -19.90 25.70 260.00
> 4969.00 550.00 -11.10 -20.10 27.00 263.00
> 5230.00 531.60 -13.60 -21.00 27.00 263.00
> 5692.00 500.00 -17.60 -34.00 -9999.00 -9999.00
> 5831.00 490.80 -19.10 -36.80 -9999.00 -9999.00
> 12059.00 212.00 -19.10 -37.10 39.60 -9999.00
>
>
>
>Unidata Support wrote:
>
>> Matthew,
>>
>> It could be the need to interpolate temperature and dewpoint over
>> levels missing data, or something else. Remember that the STNDEX allows you
>> to specify the depth of the layer from which the lifted parcel
>> is computed. The default for CAPE is CAPE!500. Verying the depth
>> of the layer of course can change the computed value especially
>> if the boundary layer lape rate causes the surface temperature value
>> or moinsture not to be representative of the layer.
>>
>> Can you provide me with the soundings for one of the times below.
>> Snlist output for all levels would be fine.
>>
>> Steve Chiswell
>> Unidata User Support
>>
>> >From: "Matthew Menne" <address@hidden>
>> >Organization: National Climatic Data Center, NOAA
>> >Keywords: 200203281838.g2SIc7a22625
>>
>> >This is a multi-part message in MIME format.
>> >--------------6EECDA8CE93B4F00786AB76F
>> >Content-Type: text/plain; charset=us-ascii
>> >Content-Transfer-Encoding: 7bit
>> >
>> >Hello,
>> >
>> >I am calculating a number of sounding parameters for soundings from the
>> >CD-ROM "Radiosonde Data for North America". I used what I believe to be
>> >your latest version of the fsltogem program to convert from the FSL to
>> >GEMPAK format. Using SNLIST, I occasionally get values of CAPE=0 for
>> >soundings that I think should have non-zero CAPE. At first I thought
>> >the it must be that either LFC or EL or both could not be obtained.
>> >However, I checked a few examples using the NSHARP program and it looks
>> >like at least in some cases the sounding may be OK, and NSHARP gives
>> >reasonable values CAPE, the LI, etc. I'll provide few station/days as
>> >examples where NSHARP calculates non-zero CAPE and SNLIST calculates
>> >zero. They all happen to be from 1996 but this problem occurs in other
>> >years that I've looked at.
>> >
>> >Station (WMO) Date/Time
>> >72340 03/31/1996 0000z
>> >72451 05/14/1996 1200Z
>> >72451 09/07/1996 1200Z
>> >72456 05/25/1996 1200Z
>> >
>> >Any ideas regarding what may be happening are most appreciated.
>> >
>> >thanks,
>> >
>> >Matthew Menne
>> >
>> >--------------6EECDA8CE93B4F00786AB76F
>> >Content-Type: text/x-vcard; charset=us-ascii;
>> > name="Matthew.Menne.vcf"
>> >Content-Transfer-Encoding: 7bit
>> >Content-Description: Card for Matthew.Menne
>> >Content-Disposition: attachment;
>> > filename="Matthew.Menne.vcf"
>> >
>> >begin:vcard
>> >n:Menne;Matthew
>> >tel;work:(828) 271-4449
>> >x-mozilla-html:FALSE
>> >org:National Climatic Data Center/NOAA;Scientific Services Division
>> >version:2.1
>> >email;internet:address@hidden
>> >adr;quoted-printable:;;151 Patton Avenue=0D=0A;Asheville;NC;28801;USA
>> >fn:Matthew Menne
>> >end:vcard
>> >
>> >--------------6EECDA8CE93B4F00786AB76F--
>> >
>>
>> ****************************************************************************
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