Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 251007
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0407 MDT Thursday, September 25, 2014

This forecast is for Thursday, September 25, 2014:

If the trigger temperature of 71.9 F/22.1 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 882 ft/min (4.5 m/s)
   Maximum height of thermals.................. 16444 ft MSL (9274 ft AGL)

Forecast maximum temperature................... 77.0 F/25.5 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 10876 ft MSL (3706 ft AGL)
Thermal soaring outlook for Friday 09/26....... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... Same
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 15525 ft MSL (8355 ft AGL)
Wave soaring outlook for Friday 09/26.......... Poor

Remarks...

Sunrise/Sunset.................... 06:49:27 / 18:52:41 MDT
Total possible sunshine........... 12 hr 3 min 14 sec (723 min 14 sec)
Altitude of sun at 12:50:35 MDT... 50.02 degrees

Upper air data from numerical model forecast valid on 09/25/2014 at 0600 MDT

Freezing level.................. 15257 ft MSL (8087 ft AGL)
Convective condensation level... 16318 ft MSL (9148 ft AGL)
Lifted condensation level....... 16425 ft MSL (9255 ft AGL)
Lifted index.................... +0.3
K index......................... +21.1

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -65.9 -86.6   010   11    6   3.1   1.7      M     M       M      M    M
 45000  -60.4 -76.7   010   22   11   4.9   2.7      M     M       M      M    M
 40000  -52.8 -63.0   015   31   16   6.4   3.5      M     M       M      M    M
 38000  -48.5 -55.3   035   31   16   6.4   3.5      M     M       M      M    M
 36000  -44.7 -48.5   050   34   17   7.0   3.8      M     M       M      M    M
 34000  -39.8 -39.6   045   33   17   8.1   4.4      M     M       M      M    M
 32000  -35.0 -31.0   040   33   17   8.4   4.6      M     M       M      M    M
 30000  -30.4 -22.7   040   32   17   7.6   4.2   39.8 103.6    11.4      M    M
 29000  -28.2 -18.8   035   32   16   7.6   4.2   39.0 102.2    11.0      M    M
 28000  -25.9 -14.6   035   31   16   7.6   4.2   38.3 101.0    10.5      M    M
 27000  -23.6 -10.5   040   29   15   7.6   4.2   37.4  99.3     9.9      M    M
 26000  -21.4  -6.5   040   27   14   7.6   4.2   36.6  97.9     9.4      M    M
 25000  -19.1  -2.4   045   25   13   7.5   4.1   35.9  96.6     8.9      M    M
 24000  -16.6   2.1   045   22   11   6.6   3.6   34.5  94.0     7.8      M    M
 23000  -14.6   5.7   050   19   10   6.6   3.6   33.4  92.1     7.0      M    M
 22000  -12.6   9.3   050   16    8   6.6   3.6   32.4  90.2     6.1      M    M
 21000  -10.7  12.7   050   13    7   6.6   3.6   31.2  88.1     5.2      M    M
 20000   -8.7  16.3   045   11    5   6.6   3.6   30.1  86.2     4.3      M    M
 19500   -7.7  18.1   045    9    5   6.2   3.4   29.7  85.4     3.9      M    M
 19000   -7.0  19.4   035    9    5   5.1   2.8   28.9  84.0     3.2      M    M
 18500   -6.2  20.8   020    9    5   5.2   2.9   28.1  82.6     2.5      M    M
 18000   -5.5  22.1   010    9    5   5.8   3.2   27.4  81.3     1.8      M    M
 17500   -4.7  23.5   005    9    5   5.9   3.2   26.7  80.1     1.2      M    M
 17000   -3.8  25.2   360    9    5   6.3   3.5   26.1  79.0     0.5      M    M
 16500   -2.9  26.8   360    8    4   7.1   3.9   25.6  78.1     0.1      M    M
 16000   -1.8  28.8   360    7    4   6.9   3.8   25.2  77.4    -0.4    843  4.3
 15500   -0.7  30.7   360    6    3   9.4   5.2   24.9  76.9    -0.7    794  4.0
 15000    0.6  33.1   350    5    3   9.3   5.1   24.9  76.7    -0.9    740  3.8
 14500    1.8  35.2   335    4    2   8.4   4.6   24.7  76.5    -1.1    688  3.5
 14000    3.0  37.4   325    3    2   8.2   4.5   24.5  76.1    -1.4    639  3.2
 13500    4.2  39.6   315    3    1   8.4   4.6   24.2  75.6    -1.7    589  3.0
 13000    5.4  41.7   310    2    1   8.5   4.6   24.1  75.3    -1.9    536  2.7
 12500    6.7  44.1   310    1    1   7.0   3.8   23.9  75.0    -2.1    483  2.5
 12000    7.9  46.2   285    2    1   9.7   5.3   23.5  74.4    -2.4    434  2.2
 11750    8.5  47.3   280    2    1   9.2   5.0   23.5  74.3    -2.5    406  2.1
 11500    9.2  48.6   275    3    1   8.8   4.8   23.5  74.2    -2.5    378  1.9
 11250    9.8  49.6   265    3    2   7.9   4.3   23.4  74.0    -2.6    353  1.8
 11000   10.4  50.7   260    4    2   7.1   3.9   23.2  73.7    -2.8    328  1.7
 10750   10.9  51.6   250    5    2   6.8   3.7   23.0  73.3    -3.0    306  1.6
 10500   11.4  52.5   245    5    3   6.8   3.7   22.7  72.9    -3.2    283  1.4
 10250   11.9  53.4   240    6    3   6.6   3.6   22.5  72.5    -3.5    260  1.3
 10000   12.4  54.3   235    7    4   6.5   3.6   22.2  72.0    -3.7    238  1.2
  9750   13.3  55.9   225   10    5   5.7   3.1   21.6  70.9    -4.3    198  1.0
  9500   13.7  56.7   220   10    5   7.0   3.8   21.4  70.5    -4.6    176  0.9
  9250   14.3  57.7   215   11    6   7.4   4.1   21.2  70.1    -4.8    153  0.8
  9000   14.8  58.6   215   11    6   6.6   3.6   21.0  69.8    -5.0    129  0.7
  8750   15.3  59.5   210   12    6   6.3   3.4   20.7  69.3    -5.3    108  0.5
  8500   15.8  60.4   210   12    6   6.8   3.7   20.5  68.9    -5.5     86  0.4
  8250   16.3  61.3   210   11    6   7.1   3.9   20.3  68.5    -5.8     63  0.3
  8000   16.8  62.2   215   10    5   6.0   3.3   20.1  68.1    -6.0     40  0.2
  7750   16.8  62.2   210    9    5  -9.2  -5.0   19.4  66.8    -6.7     32  0.2
  7500   15.3  59.5   230    6    3 -30.5 -16.7   17.1  62.7    -9.0     72  0.4
  7250   13.7  56.7   270    5    3   6.2   3.4   14.8  58.6   -11.3    111  0.6
  7000      M     M     M    M    M     M     M      M     M       M      M    M
  6750      M     M     M    M    M     M     M      M     M       M      M    M

 * * * * * * Numerical weather prediction model forecast data valid * * * * * *

           09/25/2014 at 0900 MDT          |       09/25/2014 at 1200 MDT
                                           |
K index... +16.0  LI... +1.0               | K index... +12.3  LI... +0.6
CAPE... 0.0  CIN... -0.8                   | CAPE... +5.5  CIN... -24.3
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -65.9 -86.6  015  12  6   2.8   1.5 | -65.8 -86.4  005  13  7   2.8   1.5
 45000 -60.7 -77.3  015  20 10   4.7   2.6 | -60.6 -77.1  015  20 10   4.7   2.6
 40000 -53.3 -63.9  020  29 15   6.9   3.8 | -52.7 -62.9  025  28 14   7.1   3.9
 38000 -48.6 -55.5  035  29 15   7.0   3.8 | -48.5 -55.3  030  27 14   7.1   3.9
 36000 -44.4 -47.9  045  30 15   7.3   4.0 | -44.3 -47.7  035  26 13   7.3   4.0
 34000 -39.7 -39.5  045  33 17   7.9   4.3 | -39.5 -39.1  045  30 16   7.9   4.3
 32000 -35.0 -31.0  045  35 18   8.1   4.4 | -34.8 -30.6  050  36 18   8.1   4.5
 30000 -30.3 -22.5  045  35 18   7.8   4.3 | -30.3 -22.5  055  34 17   7.5   4.1
 29000 -28.0 -18.4  050  35 18   7.8   4.3 | -28.1 -18.6  060  32 17   7.5   4.1
 28000 -25.7 -14.3  050  34 18   7.3   4.0 | -25.8 -14.4  060  31 16   7.4   4.0
 27000 -23.5 -10.3  050  31 16   7.3   4.0 | -23.1  -9.6  065  28 14   7.4   4.0
 26000 -21.4  -6.5  055  27 14   7.3   4.0 | -20.9  -5.6  070  26 13   7.4   4.0
 25000 -19.2  -2.6  055  24 12   7.2   4.0 | -18.6  -1.5  075  24 12   7.5   4.1
 24000 -16.5   2.3  055  21 11   7.1   3.9 | -16.4   2.5  070  21 11   7.6   4.2
 23000 -14.4   6.1  055  19 10   7.1   3.9 | -14.1   6.6  070  19 10   7.7   4.2
 22000 -12.3   9.9  055  17  9   7.0   3.8 | -11.9  10.6  065  16  8   6.9   3.8
 21000 -10.3  13.5  055  15  8   7.0   3.8 |  -9.9  14.2  060  14  7   6.7   3.7
 20000  -8.2  17.2  055  13  6   7.0   3.8 |  -7.9  17.8  055  13  7   6.8   3.7
 19500  -7.2  19.0  050  11  6   7.2   3.9 |  -6.9  19.6  055  12  6   6.9   3.8
 19000  -6.1  21.0  050  11  6   7.5   4.1 |  -5.9  21.4  055  11  6   7.1   3.9
 18500  -4.9  23.2  050  10  5   7.7   4.2 |  -4.8  23.4  055  10  5   7.1   3.9
 18000  -3.9  25.0  045  10  5   5.2   2.8 |  -3.8  25.2  055  10  5   6.8   3.7
 17500  -3.3  26.1  030   9  5   5.1   2.8 |  -2.8  27.0  050   9  5   6.7   3.7
 17000  -2.6  27.3  015   9  5   5.6   3.1 |  -1.8  28.8  045   9  4   6.7   3.7
 16500  -1.7  28.9  010   9  4   6.4   3.5 |  -0.9  30.4  040   8  4   6.5   3.6
 16000  -0.8  30.6  005   8  4   6.3   3.5 |   0.1  32.2  030   8  4   6.6   3.6
 15500   0.2  32.4  360   7  4   7.0   3.8 |   1.0  33.8  020   8  4   6.6   3.6
 15000   1.1  34.0  350   6  3   6.9   3.8 |   2.0  35.6  005   7  4   6.6   3.6
 14500   2.2  36.0  335   5  2   8.0   4.4 |   2.9  37.2  350   7  3   7.3   4.0
 14000   3.3  37.9  320   4  2   8.3   4.5 |   3.9  39.0  330   6  3   7.8   4.3
 13500   4.4  39.9  290   3  2   8.1   4.5 |   5.5  41.9  305   6  3   7.5   4.1
 13000   5.5  41.9  275   3  1   7.9   4.3 |   6.5  43.7  285   5  2   7.6   4.2
 12500   6.6  43.9  250   2  1   7.2   4.0 |   7.5  45.5  260   5  2   7.2   3.9
 12000   7.8  46.0  225   2  1   9.4   5.2 |   8.7  47.7  245   5  3   7.9   4.3
 11750   8.5  47.3  215   2  1   9.1   5.0 |   9.2  48.6  235   5  3   7.9   4.3
 11500   9.2  48.6  205   3  1   9.0   4.9 |   9.8  49.6  225   5  3   8.4   4.6
 11250   9.9  49.8  205   3  2   8.5   4.6 |  10.5  50.9  220   6  3   8.5   4.7
 11000  10.5  50.9  205   3  2   8.2   4.5 |  11.1  52.0  220   6  3   8.2   4.5
 10750  11.1  52.0  205   4  2   8.2   4.5 |  11.7  53.1  215   6  3   8.3   4.5
 10500  11.7  53.1  210   4  2   8.1   4.5 |  12.3  54.1  210   7  3   8.2   4.5
 10250  12.3  54.1  210   5  2   8.0   4.4 |  12.8  55.0  205   7  4   8.1   4.5
 10000  12.9  55.2  215   6  3   7.8   4.3 |  13.4  56.1  195   7  4   8.7   4.8
  9750  13.9  57.0  220   7  4   6.5   3.6 |  14.1  57.4  190   8  4   9.2   5.1
  9500  14.4  57.9  220   8  4   7.1   3.9 |  14.8  58.6  185   8  4   9.5   5.2
  9250  15.0  59.0  220   8  4   7.2   3.9 |  15.5  59.9  185   8  4   9.8   5.4
  9000  15.5  59.9  220   9  4   7.0   3.9 |  16.2  61.2  185   8  4   9.6   5.3
  8750  16.0  60.8  220   9  5   6.3   3.4 |  16.9  62.4  180   8  4   9.8   5.4
  8500  16.4  61.5  220   9  5   5.6   3.1 |  17.7  63.9  180   9  4  10.5   5.7
  8250  16.8  62.2  220   8  4   6.0   3.3 |  18.5  65.3  180   9  4  10.9   6.0
  8000  17.3  63.1  220   7  4   4.5   2.5 |  19.3  66.7  175   9  4  10.6   5.8
  7750  17.5  63.5  215   7  4   4.1   2.2 |  20.1  68.2  175   9  4  11.2   6.2
  7500  17.8  64.0  220   5  2   8.0   4.4 |  20.9  69.6  175   9  5  11.9   6.5
  7250  18.2  64.8  235   2  1  -0.1  -0.1 |  21.8  71.2  175   9  4  11.7   6.4
  7000     M     M    M   M  M     M     M |  22.7  72.9  175   8  4  11.9   6.5
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           09/25/2014 at 1500 MDT          |       09/25/2014 at 1800 MDT
                                           |
K index... +13.0  LI... +0.1               | K index... +12.0  LI... +0.2
CAPE... +69.9  CIN... -56.6                | CAPE... +76.3  CIN... -30.9
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -65.9 -86.6  030  12  6   2.8   1.5 | -65.5 -85.9  035  12  6   2.0   1.1
 45000 -60.6 -77.1  020  20 10   5.0   2.8 | -60.9 -77.6  025  20 10   5.3   2.9
 40000 -52.7 -62.9  030  26 13   6.9   3.8 | -52.6 -62.7  035  23 12   6.9   3.8
 38000 -48.6 -55.5  030  26 13   6.9   3.8 | -48.5 -55.3  030  23 12   6.9   3.8
 36000 -44.4 -47.9  030  25 13   6.9   3.8 | -44.3 -47.7  025  25 13   6.8   3.7
 34000 -39.2 -38.6  045  28 15   7.9   4.3 | -39.2 -38.6  045  24 13   7.7   4.2
 32000 -34.4 -29.9  060  33 17   7.9   4.3 | -34.6 -30.3  065  27 14   7.8   4.3
 30000 -30.1 -22.2  065  29 15   7.2   3.9 | -30.1 -22.2  070  25 13   7.4   4.1
 29000 -27.9 -18.2  070  27 14   7.2   3.9 | -27.8 -18.0  075  24 12   7.4   4.1
 28000 -25.7 -14.3  075  26 13   7.7   4.2 | -25.6 -14.1  080  23 12   7.4   4.1
 27000 -23.4 -10.1  075  25 13   7.6   4.2 | -23.4 -10.1  080  22 11   7.4   4.1
 26000 -21.1  -6.0  080  24 12   7.6   4.2 | -21.1  -6.0  080  22 11   7.4   4.1
 25000 -18.8  -1.8  080  24 12   7.6   4.2 | -18.9  -2.0  085  21 11   7.5   4.1
 24000 -16.6   2.1  080  21 11   7.5   4.1 | -16.6   2.1  080  19 10   7.7   4.2
 23000 -14.3   6.3  075  18  9   7.5   4.1 | -14.3   6.3  080  16  8   7.7   4.2
 22000 -12.1  10.2  070  16  8   7.2   3.9 | -12.0  10.4  075  14  7   7.3   4.0
 21000 -10.0  14.0  065  13  7   7.0   3.9 |  -9.9  14.2  065  12  6   6.9   3.8
 20000  -7.9  17.8  055  11  6   7.1   3.9 |  -7.9  17.8  050  10  5   7.0   3.8
 19500  -6.9  19.6  050  11  5   7.2   4.0 |  -6.8  19.8  040  10  5   7.0   3.9
 19000  -5.8  21.6  050  10  5   7.3   4.0 |  -5.8  21.6  035   9  5   7.0   3.8
 18500  -4.8  23.4  045   9  5   7.3   4.0 |  -4.8  23.4  030   8  4   7.0   3.9
 18000  -3.7  25.3  045   9  4   7.1   3.9 |  -3.8  25.2  025   8  4   7.3   4.0
 17500  -2.7  27.1  040   8  4   6.9   3.8 |  -2.7  27.1  020   7  4   7.5   4.1
 17000  -1.6  29.1  035   7  4   6.9   3.8 |  -1.5  29.3  015   7  3   7.5   4.1
 16500  -0.7  30.7  025   7  4   6.5   3.6 |  -0.5  31.1  010   7  3   7.1   3.9
 16000   0.8  33.4  010   8  4   6.7   3.7 |   1.1  34.0  355   7  4   7.1   3.9
 15500   1.8  35.2  360   8  4   7.2   4.0 |   2.1  35.8  345   8  4   6.9   3.8
 15000   2.8  37.0  345   9  5   7.2   4.0 |   3.1  37.6  340   9  5   7.0   3.8
 14500   3.8  38.8  335  10  5   8.3   4.6 |   4.0  39.2  335   9  5   7.8   4.3
 14000   4.9  40.8  330  10  5   8.4   4.6 |   5.1  41.2  330   8  4   8.0   4.4
 13500   6.1  43.0  320   9  5   8.7   4.8 |   6.1  43.0  330   6  3   8.1   4.5
 13000   7.3  45.1  320   7  4   8.9   4.9 |   7.2  45.0  335   3  1   8.2   4.5
 12500   8.5  47.3  315   5  2   6.9   3.8 |   8.3  46.9  130   1  1   5.6   3.1
 12000   9.5  49.1  275   2  1   7.4   4.0 |   9.2  48.6  165   4  2   7.2   3.9
 11750  10.0  50.0  230   2  1   7.5   4.1 |   9.7  49.5  165   5  3   6.5   3.6
 11500  10.5  50.9  195   3  1   6.1   3.3 |  10.2  50.4  170   6  3   7.7   4.2
 11250  10.9  51.6  185   5  2   5.5   3.0 |  10.8  51.4  170   7  4   7.3   4.0
 11000  11.3  52.3  180   6  3   6.7   3.7 |  11.2  52.2  175   9  4   5.8   3.2
 10750  11.8  53.2  175   8  4   6.1   3.3 |  11.6  52.9  175  10  5   5.6   3.1
 10500  12.3  54.1  170   9  5   8.1   4.4 |  12.1  53.8  175  11  5   6.8   3.8
 10250  13.0  55.4  170  10  5  10.0   5.5 |  12.6  54.7  175  11  6   8.4   4.6
 10000  13.7  56.7  170  10  5   9.3   5.1 |  13.2  55.8  175  11  6   7.8   4.3
  9750  14.4  57.9  170  10  5   9.3   5.1 |  13.8  56.8  170  12  6   7.2   4.0
  9500  15.1  59.2  170  10  5   9.5   5.2 |  14.4  57.9  170  13  7   8.4   4.6
  9250  15.8  60.4  170  11  5   9.7   5.3 |  15.0  59.0  170  13  7   9.3   5.1
  9000  16.5  61.7  170  11  5   9.9   5.4 |  15.7  60.3  170  14  7   9.3   5.1
  8750  17.3  63.1  170  11  6  10.8   5.9 |  16.5  61.7  170  14  7  10.3   5.6
  8500  18.1  64.6  170  11  6  10.6   5.8 |  17.2  63.0  170  14  7  10.3   5.6
  8250  18.9  66.0  170  11  6  10.3   5.6 |  18.0  64.4  170  14  7   9.8   5.4
  8000  19.6  67.3  170  11  6   9.9   5.4 |  18.7  65.7  170  13  7  10.0   5.5
  7750  20.4  68.7  170  11  6  11.9   6.5 |  19.4  66.9  170  13  7   9.5   5.2
  7500  21.4  70.5  170  11  6  12.7   6.9 |  20.1  68.2  170  13  7   6.8   3.8
  7250  22.2  72.0  165  11  6  10.8   5.9 |  20.5  68.9  170  12  6   5.0   2.8
  7000  23.0  73.4  165  11  5  12.4   6.8 |  20.9  69.6  170  11  6   6.4   3.5
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

This product is issued twice per day, once by approximately 0630 MST/0730 MDT
(1330 UTC) and again by approximately 1830 MST/1930 MDT (0130 UTC).  It is not
continuously monitored nor updated after its initial issuance.

The information contained herein is based on rawinsonde observation and/or
numerical weather prediction model data taken near the Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 meters)

and may not be representative of other areas along the Front Range of the
Colorado Rocky Mountains.  Note that some elevations in numerical weather
prediction models differ from actual station elevations, which can lead to
data which appear to be below ground.  Erroneous data such as these should
not be used.

The content and format of this report as well as the issuance times are subject
to change without prior notice.  Comments and suggestions are welcome and should
be directed to one of the addresses or phone numbers shown at the bottom of this
page.  To expedite a response to comments, be sure to mention your interest in
the soaring forecast.

DEFINITIONS:

CAPE (Convective Available Potential Energy) - An integrated measure of the
     energy available for convective development, also known as the positive
     area on a thermodynamic diagram.  Units are Joules per kilogram.  Larger
     values are indicative of greater instability and the possibility of
     stronger convective activity, including thunderstorms.  Values around or
     greater than 1000 suggest the possibility of severe weather should
     convective activity develop.

CIN (Convective Inhibition) - An integrated measure of the amount of energy
     needed to initiate convective activity, also known as the negative area on
     a thermodynamic diagram.  Units are Joules per kilogram.  The more negative
     this number, the more energy is required to initiate convection.  This
     inhibitive energy can be overcome through surface heating, cooling aloft,
     lifting mechanisms (orographic, frontal, gravity waves, etc.)

Convective Condensation Level - The height to which an air parcel possessing the
     average saturation mixing ratio in the lowest 4000 feet of the airmass,
     if heated sufficiently from below, will rise dry adiabatically until it
     just becomes saturated.  It estimates the base of cumulus clouds that are
     produced by surface heating only.

Convection Temperature (ConvectionT) - The surface temperature required to make
     the airmass dry adiabatic up to the given level.  It can be considered a
     "trigger temperature" for that level.

Freezing Level - The height where the temperature is zero degrees Celsius.

Height of Stable Layer - The height (between 12,000 and 18,000 feet above
     mean sea level) where the smallest lapse rate exists.  The location and
     existence of this feature is important in the generation of mountain
     waves.

K Index - A measure of stability which combines the temperature difference
     between approximately 5,000 and 18,000 feet above the surface, the amount
     of moisture at approximately 5,000 feet above the surface, and a measure
     of the dryness at approximately 10,000 feet above the surface.  Larger
     positive numbers indicate more instability and a greater likelihood of
     thunderstorm development.  One interpretation of K index values regarding
     soaring in the western United States is given in WMO Technical Note 158
     and is reproduced in the following table:

          below -10    no or weak thermals
           -10 to 5    dry thermals or 1/8 cumulus with moderate thermals
            5 to 15    good soaring conditions
           15 to 20    good soaring conditions with occasional showers
           20 to 30    excellent soaring conditions, but increasing
                       probability of showers and thunderstorms
           above 30    more than 60 percent probability of thunderstorms

Lapse Rate - The change with height of the temperature. Negative values indicate
     inversions.

Lifted Condensation Level - The height to which an air parcel possessing the
     average dew point in the lowest 4000 feet of the airmass and the forecast
     maximum temperature must be lifted dry adiabatically to attain saturation.

Lifted Index (LI) - The difference between the environmental temperature at a
     level approximately 18,000 feet above the surface and the temperature of
     an air parcel lifted dry adiabatically from the surface to its lifted
     condensation level and then pseudoadiabatically thereafter to this same
     level.  The parcel`s initial temperature is the forecast maximum
     temperature and its dew point is the average dew point in the lowest 4000
     feet of the airmass.  Negative values are indicative of instability with
     positive values showing stable conditions.

Lift Rate - An experimental estimate of the strength of thermals.  It is
     computed the same way as the maximum rate of lift but uses the actual
     level rather than the maximum height of thermals in the calculation.
     Also, none of the empirical adjustments based on cloudiness and K-index
     are applied to these calculations.

Maximum Height of Thermals - The height where the dry adiabat through the
     forecast maximum temperature intersects the environmental temperature.

Maximum Rate of Lift - An estimate of the maximum strength of thermals.  It
     is computed from an empirical formula which combines the expected maximum
     height of thermals with the difference in the environmental temperatures
     between the maximum height of thermals and the temperature 4,000 feet
     above the ground.  After this computation, further empirical adjustments
     are made based on the value of the K-index and the amount and opacity of
     middle and high level cloudiness expected between the time of trigger
     temperature and the time of overdevelopment.

Middle/High Clouds - The amount and opacity of middle (altostratus, altocumulus)
     or high (cirrus, cirrostratus, cirrocumulus) clouds.  Broken means that
     between 60% and 90% of the sky is covered by the cloud, with overcast
     conditions occurring when more than 90% of the sky is covered by the cloud.
     Thin implies that the clouds are predominantly transparent, meaning that
     some sunlight is reaching the ground, in contrast to opaque which suggests
     that little sunlight is reaching the ground.

Potential Height of Wave - The minimum of the following two heights:
     1. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind direction changes by 30 degrees or more
     2. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind speed no longer increases with height

PVA/NVA - Positive vorticity advection (PVA)/negative vorticity advection (NVA)
     on the 500 millibar isobaric surface (approximately 18,000 feet above mean
     sea level).  Weak PVA has been shown to assist in mountain wave soaring.

Soaring Window - The time between the time the trigger temperature is reached
                 and the time of overdevelopment.

Thermal Index - The difference between the environmental temperature and the
     temperature at a particular level determined by following the dry adiabat
     through the forecast maximum temperature up to that level.  Negative values
     are indicative of thermal lift.

Thermal Soaring Index - An adjective rating (for sailplanes) based on the
     computed maximum rate of lift, and the wind speed and middle and high
     cloud cover expected during the soaring window (the time of the trigger
     temperature and the time of overdevelopment) according to the following:

                 Maximum rate of lift        Adjective Rating
                      >= 800 fpm                 Excellent
                 >= 400 and < 800 fpm              Good
                 >= 200 and < 400 fpm              Fair
                       < 200 fpm                   Poor

Time of Overdevelopment - The time one or more of the following phenomena,
     which essentially shut off thermal lift, is expected to occur:
     1. formation of broken to overcast convective cloud cover
     2. formation of scattered to numerous downbursts
     3. initiation of widespread precipitation

Time of Trigger Temperature - The time the surface temperature is expected to
     reach the trigger temperature.

Trigger Temperature - The surface temperature required to make the first 4000
     feet of the atmosphere dry adiabatic.

Wave Soaring Index - An empirical, adjective rating (for sailplanes) which
     attempts to combine a variety of phenomena important in mountain wave
     soaring into a single index number.  Objective points are assigned to
     these phenomena: wind speed and direction at 14,000 ft MSL, the static
     stability in the 12,000-18,000 ft MSL layer, the wind speed gradient above
     the stable layer, jet stream location and frontal and upper trough
     movements.

042613



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