Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 261235
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0635 MDT Thursday, April 26, 2018

This forecast is for Thursday, April 26, 2018:

If the trigger temperature of 50.2 F/10.1 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 508 ft/min (2.6 m/s)
   Maximum height of thermals.................. 13316 ft MSL (5727 ft AGL)

Forecast maximum temperature................... 53.0 F/12.1 C
Time of trigger temperature.................... 1430 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................. 10846 ft MSL (3257 ft AGL)
Thermal soaring outlook for Friday 04/27....... Excellent

Wave Soaring Index............................. Not available

Remarks...

Effective May 18, 2018 this product will no longer be issued.
If you have any questions, please send email to:
    jennifer.stark@noaa.gov
    paul.wolyn@noaa.gov


Sunrise/Sunset.................... 06:07:09 / 19:46:57 MDT
Total possible sunshine........... 13 hr 39 min 49 sec (819 min 49 sec)
Altitude of sun at 12:57:03 MDT... 64.68 degrees

Upper air data from numerical model forecast valid on 04/26/2018 at 0600 MDT

Freezing level.................. 9367 ft MSL (1778 ft AGL)
Convective condensation level... 17605 ft MSL (10016 ft AGL)
Lifted condensation level....... 16331 ft MSL (8742 ft AGL)
Lifted index.................... +5.0
K index......................... +14.0

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  -59.3 -74.7   310   16    8   1.1   0.6      M     M       M      M    M
 45000  -57.7 -71.9   305   24   13  -0.8  -0.4      M     M       M      M    M
 40000  -58.6 -73.5   300   29   15  -0.6  -0.3      M     M       M      M    M
 38000  -56.9 -70.4   295   30   16   5.0   2.8      M     M       M      M    M
 36000  -53.9 -65.0   290   31   16   5.0   2.8      M     M       M      M    M
 34000  -50.6 -59.1   285   31   16   6.8   3.7      M     M       M      M    M
 32000  -46.0 -50.8   275   31   16   6.8   3.7      M     M       M      M    M
 30000  -41.7 -43.1   275   30   15   7.6   4.1   27.0  80.6    11.8      M    M
 29000  -39.5 -39.1   275   29   15   7.6   4.1   26.1  78.9    11.2      M    M
 28000  -37.2 -35.0   275   28   14   7.6   4.1   25.3  77.6    10.7      M    M
 27000  -35.0 -31.0   275   26   14   7.3   4.0   24.6  76.2    10.3      M    M
 26000  -32.8 -27.0   275   25   13   7.3   4.0   23.5  74.4     9.6      M    M
 25000  -30.7 -23.3   275   24   12   7.3   4.0   22.6  72.8     8.9      M    M
 24000  -28.5 -19.3   280   23   12   7.5   4.1   21.9  71.4     8.4      M    M
 23000  -26.2 -15.2   280   22   11   7.7   4.2   21.0  69.8     7.8      M    M
 22000  -23.9 -11.0   285   21   11   7.7   4.2   20.3  68.5     7.3      M    M
 21000  -21.6  -6.9   285   20   10   6.5   3.6   19.6  67.2     6.7      M    M
 20000  -19.7  -3.5   290   19   10   6.5   3.6   18.4  65.0     5.8      M    M
 19500  -18.8  -1.8   290   18    9   6.5   3.6   17.8  64.0     5.3      M    M
 19000  -17.3   0.9   295   17    9   6.5   3.6   17.0  62.7     4.6      M    M
 18500  -16.4   2.5   295   17    9   6.4   3.5   16.5  61.7     4.1      M    M
 18000  -15.5   4.1   295   16    8   6.4   3.5   15.9  60.6     3.6      M    M
 17500  -14.6   5.7   295   16    8   6.8   3.7   15.4  59.7     3.1      M    M
 17000  -13.6   7.5   300   15    8   6.9   3.8   14.9  58.8     2.6      M    M
 16500  -12.6   9.3   300   15    8   7.2   3.9   14.4  58.0     2.2      M    M
 16000  -11.4  11.5   300   15    8   8.1   4.4   14.1  57.4     1.9      M    M
 15500  -10.2  13.6   305   15    8   8.1   4.5   13.8  56.9     1.6      M    M
 15000   -9.1  15.6   310   15    8   7.7   4.2   13.5  56.3     1.3      M    M
 14500   -8.0  17.6   315   15    8   7.8   4.3   13.2  55.7     1.0      M    M
 14000   -6.9  19.6   320   15    8   6.7   3.7   12.8  55.1     0.6      M    M
 13500   -5.9  21.4   325   14    7   6.5   3.6   12.3  54.1     0.2      M    M
 13000   -4.8  23.4   330   14    7   9.0   4.9   11.9  53.4    -0.2    476  2.4
 12500   -3.5  25.7   335   13    7   6.9   3.8   11.7  53.1    -0.3    421  2.1
 12000   -2.5  27.5   340   14    7   5.2   2.9   11.2  52.2    -0.8    378  1.9
 11750   -2.2  28.0   340   14    7   4.3   2.3   10.8  51.4    -1.2    360  1.8
 11500   -1.9  28.6   345   15    8   4.2   2.3   10.4  50.7    -1.6    343  1.7
 11250   -1.6  29.1   345   16    8   3.7   2.0    9.9  49.8    -2.1    326  1.7
 11000   -1.3  29.7   350   18    9   2.3   1.2    9.4  48.9    -2.5    311  1.6
 10750   -1.2  29.8   350   19   10   1.4   0.8    8.8  47.8    -3.2    300  1.5
 10500   -1.1  30.0   355   20   10   1.3   0.7    8.1  46.6    -3.8    289  1.5
 10250   -0.9  30.4   355   21   11   2.4   1.3    7.5  45.5    -4.4    278  1.4
 10000   -0.7  30.7   360   23   12   3.8   2.1    7.0  44.6    -4.9    264  1.3
  9750   -0.5  31.1   360   23   12   3.5   1.9    6.5  43.8    -5.4    249  1.3
  9500   -0.2  31.6   360   24   12   4.1   2.3    6.1  42.9    -5.9    234  1.2
  9250    0.1  32.2   360   25   13   1.9   1.0    5.6  42.1    -6.4    219  1.1
  9000    0.1  32.2   360   24   13   2.3   1.3    4.9  40.9    -7.0    210  1.1
  8750    0.4  32.7   355   23   12   4.9   2.7    4.5  40.1    -7.5    193  1.0
  8500    0.7  33.3   355   23   12   4.3   2.4    4.1  39.4    -7.9    176  0.9
  8250    1.1  34.0   350   22   11   4.1   2.2    3.7  38.7    -8.4    159  0.8
  8000    1.4  34.5   350   20   10   4.8   2.6    3.3  37.9    -8.8    143  0.7
  7750    1.8  35.2   345   15    8   7.3   4.0    3.0  37.4    -9.1    122  0.6
  7500      M     M     M    M    M     M     M      M     M       M      M    M
  7250      M     M     M    M    M     M     M      M     M       M      M    M
  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 * * * * * *

           04/26/2018 at 0900 MDT          |       04/26/2018 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +1.2        | CAPE...   +19.8    LI...       +4.6
CINH...     0.0    K Index...  +7.5        | CINH...    -5.9    K Index... -18.7
                                           |
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 -59.8 -75.6  310  15  8   1.1   0.6 | -60.9 -77.6  305  15  8   0.5   0.3
 45000 -58.1 -72.6  315  24 12   0.4   0.2 | -60.1 -76.2  315  23 12   0.7   0.4
 40000 -57.5 -71.5  325  27 14   0.4   0.2 | -59.0 -74.2  335  21 11   0.7   0.4
 38000 -55.1 -67.2  325  26 14   5.9   3.3 | -56.5 -69.7  345  24 12   6.2   3.4
 36000 -51.5 -60.7  325  25 13   5.9   3.2 | -52.8 -63.0  350  28 14   6.2   3.4
 34000 -47.9 -54.2  330  24 12   6.1   3.4 | -48.5 -55.3  360  31 16   6.8   3.7
 32000 -44.2 -47.6  325  23 12   6.1   3.4 | -44.5 -48.1  005  31 16   6.8   3.7
 30000 -40.5 -40.9  325  22 11   6.2   3.4 | -40.4 -40.7  010  32 16   6.9   3.8
 29000 -38.6 -37.5  320  21 11   6.2   3.4 | -38.3 -36.9  010  32 17   6.9   3.8
 28000 -36.7 -34.1  320  21 11   6.2   3.4 | -36.2 -33.2  015  33 17   6.9   3.8
 27000 -34.9 -30.8  320  20 10   6.2   3.4 | -34.2 -29.6  015  33 17   7.0   3.9
 26000 -32.5 -26.5  315  19 10   6.3   3.4 | -32.1 -25.8  015  33 17   7.1   3.9
 25000 -30.6 -23.1  315  18  9   6.3   3.4 | -29.9 -21.8  015  33 17   7.1   3.9
 24000 -28.8 -19.8  315  17  9   5.7   3.1 | -27.8 -18.0  015  33 17   6.8   3.7
 23000 -27.1 -16.8  315  17  9   5.4   3.0 | -25.8 -14.4  015  32 17   6.6   3.6
 22000 -25.5 -13.9  320  17  9   5.4   3.0 | -23.9 -11.0  015  32 16   6.6   3.6
 21000 -24.0 -11.2  325  17  9   4.3   2.4 | -21.9  -7.4  015  30 16   6.1   3.4
 20000 -22.7  -8.9  325  16  8   4.5   2.5 | -19.6  -3.3  010  27 14   6.1   3.3
 19500 -22.0  -7.6  330  16  8   4.5   2.5 | -18.7  -1.7  010  26 13   6.1   3.3
 19000 -21.3  -6.3  330  16  8   4.4   2.4 | -17.8  -0.0  010  25 13   6.1   3.4
 18500 -20.6  -5.1  330  16  8   6.5   3.6 | -17.1   1.2  005  23 12   3.1   1.7
 18000 -19.6  -3.3  335  16  8   6.7   3.7 | -16.6   2.1  360  21 11   3.4   1.9
 17500 -18.6  -1.5  335  16  8   7.4   4.0 | -16.1   3.0  360  19 10   3.4   1.9
 17000 -17.4   0.7  335  16  8   8.4   4.6 | -15.6   3.9  355  17  9   3.5   1.9
 16500 -16.2   2.8  335  15  8   8.4   4.6 | -15.1   4.8  345  16  8   3.9   2.1
 16000 -15.1   4.8  335  15  8   7.0   3.9 | -14.4   6.1  345  15  7   5.0   2.7
 15500 -14.0   6.8  335  14  7   7.0   3.9 | -13.7   7.3  340  14  7   5.0   2.7
 15000 -12.9   8.8  335  14  7   8.8   4.8 | -12.7   9.1  335  13  7   8.5   4.7
 14500 -11.5  11.3  335  13  7   9.0   4.9 | -11.6  11.1  330  12  6   8.3   4.5
 14000 -10.3  13.5  335  12  6   6.1   3.4 | -10.4  13.3  330  11  6   8.2   4.5
 13500  -9.5  14.9  340  12  6   5.3   2.9 |  -9.2  15.4  330  11  6   8.5   4.7
 13000  -8.8  16.2  350  12  6   5.1   2.8 |  -8.1  17.4  330  11  6   4.7   2.6
 12500  -8.0  17.6  360  13  7   4.4   2.4 |  -7.6  18.3  335  11  6   3.8   2.1
 12000  -7.4  18.7  005  13  7   6.2   3.4 |  -7.0  19.4  340  12  6   3.8   2.1
 11750  -6.9  19.6  005  14  7   8.3   4.5 |  -6.8  19.8  340  12  6   4.0   2.2
 11500  -6.3  20.7  005  15  8   7.2   3.9 |  -6.5  20.3  345  13  6   3.4   1.9
 11250  -5.9  21.4  005  16  8   4.9   2.7 |  -6.3  20.7  350  13  7   4.2   2.3
 11000  -5.6  21.9  005  16  8   4.6   2.5 |  -5.9  21.4  350  13  7   7.1   3.9
 10750  -5.2  22.6  010  17  9   5.3   2.9 |  -5.3  22.5  350  13  7   8.0   4.4
 10500  -4.8  23.4  010  18  9   5.6   3.1 |  -4.8  23.4  355  13  7   7.7   4.2
 10250  -4.4  24.1  010  19 10   3.9   2.1 |  -4.2  24.4  355  12  6   8.2   4.5
 10000  -4.2  24.4  010  20 10   4.3   2.3 |  -3.6  25.5  360  12  6   9.4   5.2
  9750  -3.8  25.2  010  20 10   6.3   3.5 |  -2.9  26.8  360  12  6  10.0   5.5
  9500  -3.3  26.1  010  20 10   5.6   3.1 |  -2.1  28.2  360  12  6   9.9   5.4
  9250  -2.9  26.8  010  20 11   6.3   3.5 |  -1.4  29.5  360  12  6   9.5   5.2
  9000  -2.4  27.7  005  20 10   9.0   4.9 |  -0.7  30.7  360  12  6  10.4   5.7
  8750  -1.6  29.1  005  18  9  10.5   5.8 |   0.1  32.2  360  12  6  11.4   6.2
  8500  -0.8  30.6  360  17  9  10.2   5.6 |   1.0  33.8  360  12  6  11.2   6.1
  8250  -0.1  31.8  360  16  8  10.4   5.7 |   1.8  35.2  360  12  6  10.4   5.7
  8000   0.9  33.6  355  15  8  16.0   8.8 |   2.8  37.0  360  11  6  19.3  10.6
  7750   4.0  39.2  355  11  6   9.0   4.9 |   4.9  40.8  360  10  5  36.1  19.8
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7000     M     M    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     M     M

           04/26/2018 at 1500 MDT          |       04/26/2018 at 1800 MDT
                                           |
CAPE...    +2.9    LI...       +5.0        | CAPE...     0.0    LI...       +3.7
CINH...     0.0    K Index... -13.3        | CINH...     0.0    K Index...  -9.5
                                           |
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 -61.1 -78.0  305  15  8  -0.2  -0.1 | -61.5 -78.7  310  15  8  -1.0  -0.5
 45000 -61.3 -78.3  320  19 10   1.8   1.0 | -62.8 -81.0  325  20 10   1.5   0.8
 40000 -58.8 -73.8  345  19 10   1.6   0.9 | -60.9 -77.6  350  20 10   1.4   0.8
 38000 -56.5 -69.7  350  21 11   4.9   2.7 | -58.1 -72.6  355  21 11   6.0   3.3
 36000 -53.6 -64.5  355  24 13   4.9   2.7 | -54.5 -66.1  360  21 11   6.0   3.3
 34000 -49.6 -57.3  360  27 14   7.5   4.1 | -50.5 -58.9  005  22 11   7.7   4.2
 32000 -45.1 -49.2  005  26 13   7.5   4.1 | -45.3 -49.5  005  22 11   7.7   4.2
 30000 -40.6 -41.1  005  26 13   7.7   4.2 | -40.5 -40.9  010  22 11   8.2   4.5
 29000 -38.3 -36.9  005  26 13   7.7   4.2 | -38.1 -36.6  010  21 11   8.2   4.5
 28000 -36.0 -32.8  010  25 13   7.7   4.2 | -35.6 -32.1  015  21 11   8.2   4.5
 27000 -33.7 -28.7  010  25 13   7.0   3.8 | -33.1 -27.6  015  20 10   8.3   4.5
 26000 -31.6 -24.9  010  25 13   7.1   3.9 | -30.6 -23.1  015  20 10   8.3   4.5
 25000 -29.5 -21.1  010  25 13   7.1   3.9 | -28.2 -18.8  015  20 10   8.3   4.6
 24000 -27.4 -17.3  005  25 13   7.2   4.0 | -25.8 -14.4  010  20 10   6.5   3.6
 23000 -25.2 -13.4  010  25 13   7.2   4.0 | -23.8 -10.8  010  20 10   6.7   3.7
 22000 -23.0  -9.4  010  25 13   7.2   4.0 | -21.8  -7.2  010  20 10   6.7   3.7
 21000 -20.9  -5.6  010  25 13   7.7   4.2 | -19.8  -3.6  010  19 10   6.6   3.6
 20000 -18.6  -1.5  010  24 12   7.6   4.2 | -17.9  -0.2  010  18  9   6.6   3.6
 19500 -16.8   1.8  015  23 12   7.6   4.2 | -16.4   2.5  010  17  9   6.6   3.6
 19000 -15.7   3.7  015  22 12   7.4   4.0 | -15.4   4.3  010  17  9   6.8   3.7
 18500 -14.7   5.5  015  21 11   6.6   3.6 | -14.4   6.1  005  16  8   7.0   3.9
 18000 -13.7   7.3  015  20 10   6.6   3.6 | -13.3   8.1  005  16  8   7.1   3.9
 17500 -12.7   9.1  015  19 10   6.4   3.5 | -12.3   9.9  360  15  8   6.4   3.5
 17000 -11.7  10.9  015  19 10   6.2   3.4 | -11.4  11.5  360  15  8   6.4   3.5
 16500 -10.8  12.6  015  18  9   4.4   2.4 | -10.4  13.3  360  14  7   6.6   3.6
 16000 -10.4  13.3  005  17  9   2.4   1.3 |  -9.4  15.1  355  14  7   6.7   3.7
 15500 -10.1  13.8  360  17  9   2.4   1.3 |  -8.4  16.9  355  14  7   6.1   3.4
 15000  -9.6  14.7  350  16  8   3.4   1.8 |  -7.6  18.3  350  14  7   4.1   2.2
 14500  -9.2  15.4  340  16  8   3.0   1.6 |  -7.0  19.4  345  15  8   4.1   2.3
 14000  -8.3  17.1  330  16  8   9.5   5.2 |  -6.2  20.8  340  14  7   6.9   3.8
 13500  -7.0  19.4  325  15  8   9.7   5.3 |  -5.3  22.5  335  14  7   6.8   3.8
 13000  -6.1  21.0  325  14  7   3.2   1.7 |  -4.1  24.6  330  13  7   9.8   5.4
 12500  -5.8  21.6  330  13  7   2.2   1.2 |  -2.8  27.0  325  13  6   9.6   5.3
 12000  -5.4  22.3  330  12  6   4.2   2.3 |  -1.8  28.8  330  12  6   4.0   2.2
 11750  -5.1  22.8  335  11  6   5.1   2.8 |  -1.5  29.3  330  11  6   4.2   2.3
 11500  -4.8  23.4  340  10  5   2.7   1.5 |  -1.3  29.7  335  10  5   3.7   2.1
 11250  -4.7  23.5  345  10  5   3.9   2.1 |  -1.1  30.0  335  10  5   3.4   1.8
 11000  -4.2  24.4  345   9  5   9.3   5.1 |  -0.8  30.6  335  10  5   3.6   2.0
 10750  -3.4  25.9  350   9  5  10.0   5.5 |  -0.6  30.9  340   9  4   3.9   2.1
 10500  -2.7  27.1  350   9  5  10.1   5.5 |  -0.3  31.5  340   8  4   2.8   1.6
 10250  -2.0  28.4  350   9  5   9.1   5.0 |  -0.1  31.8  345   7  4   5.2   2.8
 10000  -1.3  29.7  350   9  5   9.2   5.1 |   0.5  32.9  350   7  3   9.4   5.2
  9750  -0.6  30.9  350   9  5  10.3   5.6 |   1.2  34.2  355   6  3   9.8   5.4
  9500   0.2  32.4  350   9  5   9.9   5.5 |   1.9  35.4  355   6  3   9.7   5.3
  9250   0.9  33.6  350   9  5   8.9   4.9 |   2.6  36.7  355   6  3   8.9   4.9
  9000   1.6  34.9  350   9  5  10.1   5.6 |   3.3  37.9  355   6  3   9.7   5.3
  8750   2.4  36.3  350   9  5  11.8   6.5 |   4.1  39.4  360   6  3  10.9   6.0
  8500   3.3  37.9  350   9  5  11.3   6.2 |   4.9  40.8  360   6  3  10.4   5.7
  8250   4.1  39.4  350   9  5  10.4   5.7 |   5.6  42.1  360   6  3   9.6   5.3
  8000   5.0  41.0  355   9  5  18.4  10.1 |   6.4  43.5  360   6  3  13.5   7.4
  7750   7.0  44.6  355   8  4  33.2  18.2 |   7.7  45.9  360   6  3  21.2  11.6
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7000     M     M    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     M     M
________________________________________________________________________________

This product is issued twice per day, once by approximately 0630 MST/0730 MDT
(1330 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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