Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 031234
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0534 MST Saturday, December 3, 2016

This forecast is for Saturday, December 3, 2016:

If the trigger temperature of 38.1 F/3.4 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 262 ft/min (1.3 m/s)
   Maximum height of thermals.................. 8803 ft MSL (3964 ft AGL)

Forecast maximum temperature................... 38.0 F/3.8 C
Time of trigger temperature.................... 1330 MST
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................. 7104 ft MSL (2265 ft AGL)
Thermal soaring outlook for Sunday 12/04....... Fair

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

Remarks...

Sunrise/Sunset.................... 07:16:47 / 16:51:40 MST
Total possible sunshine........... 9 hr 34 min 53 sec (574 min 53 sec)
Altitude of sun at 12:04:20 MST... 28.71 degrees

Upper air data from rawinsonde observation taken on 12/03/2016 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 15195 ft MSL (10356 ft AGL)
Lifted condensation level....... 10462 ft MSL (5623 ft AGL)
Lifted index.................... +16.5
K index......................... -37.0

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  -61.6 -78.9   285   31   16   0.3   0.2  100.2 212.4    54.9      M    M
 45000  -56.4 -69.5   305   19   10   6.2   3.4   84.1 183.3    49.0      M    M
 40000  -55.5 -67.9   325   33   17   0.6   0.3   62.2 143.9    38.2      M    M
 38000  -52.3 -62.1   330   39   20   6.5   3.5   58.1 136.6    36.5      M    M
 36000  -52.0 -61.6   320   42   21   4.8   2.6   48.8 119.8    31.2      M    M
 34000  -50.0 -58.0   350   43   22   7.8   4.3   43.1 109.7    28.1      M    M
 32000  -47.9 -54.2   350   55   28   1.5   0.8   38.0 100.4    25.1      M    M
 30000  -45.8 -50.4   350   52   27   5.7   3.1   33.0  91.3    22.0      M    M
 29000  -43.5 -46.3   350   50   26   8.3   4.6   32.1  89.8    21.7      M    M
 28000  -41.3 -42.3   355   48   25   5.8   3.2   31.1  87.9    21.1      M    M
 27000  -39.0 -38.2   355   42   22   8.8   4.8   30.3  86.5    20.8      M    M
 26000  -36.3 -33.3   350   36   19   9.1   5.0   30.0  85.9    20.8      M    M
 25000  -33.5 -28.3   345   30   16   9.2   5.0   29.8  85.6    20.9      M    M
 24000  -30.8 -23.4   340   35   18   9.6   5.3   29.5  85.1    20.9      M    M
 23000  -28.4 -19.1   340   41   21   7.8   4.3   28.9  84.0    20.7      M    M
 22000  -27.1 -16.8   340   46   24  -0.8  -0.4   27.0  80.6    19.3      M    M
 21000  -25.6 -14.1   345   38   20   7.9   4.3   25.1  77.3    18.0      M    M
 20000  -23.2  -9.8   360   30   15   8.0   4.4   24.5  76.2    17.8      M    M
 19500  -21.3  -6.3   355   25   13   7.5   4.1   24.1  75.3    17.6      M    M
 19000  -21.0  -5.8   350   21   11  -1.7  -0.9   22.8  73.0    16.5      M    M
 18500  -20.9  -5.6   325   16    8   4.4   2.4   21.1  70.0    15.2      M    M
 18000  -19.9  -3.8   320   15    8   6.7   3.7   20.6  69.0    14.8      M    M
 17500  -18.9  -2.0   320   16    8   6.8   3.7   20.0  68.1    14.5      M    M
 17000  -17.9  -0.2   320   17    9   6.8   3.7   19.5  67.2    14.1      M    M
 16500  -16.8   1.8   320   17    9   6.2   3.4   19.1  66.3    13.8      M    M
 16000  -16.7   1.9   320   18    9  -0.3  -0.1   17.6  63.7    12.6      M    M
 15500  -16.1   3.0   300   19   10   5.1   2.8   16.6  61.9    11.8      M    M
 15000  -15.3   4.5   290   21   11   5.0   2.8   15.8  60.4    11.1      M    M
 14500  -14.5   5.9   280   24   12   5.1   2.8   15.0  59.0    10.5      M    M
 14000  -13.8   7.2   270   27   14   5.1   2.8   14.3  57.7     9.9      M    M
 13500  -13.1   8.4   270   28   14   2.6   1.4   13.4  56.2     9.1      M    M
 13000  -12.9   8.8   270   29   15   5.0   2.7   12.1  53.8     7.9      M    M
 12500  -13.5   7.7   265   24   12  -3.6  -2.0   10.0  50.0     5.9      M    M
 12000  -12.6   9.3   260   20   10   1.2   0.7    9.4  48.8     5.3      M    M
 11500  -12.9   8.8   260   17    9  -0.7  -0.4    7.5  45.4     3.6      M    M
 11000  -12.3   9.9   265   13    7   6.6   3.6    6.4  43.6     2.7      M    M
 10500  -11.4  11.5   270   10    5   6.2   3.4    5.8  42.5     2.2      M    M
 10250  -11.0  12.2   270    9    4   5.5   3.0    5.6  42.0     1.9      M    M
 10000  -10.5  13.1   275    7    4   7.9   4.3    5.3  41.5     1.7      M    M
  9750   -9.9  14.2   270    6    3   6.5   3.6    5.2  41.3     1.6      M    M
  9500   -9.6  14.7   265    4    2   2.8   1.5    4.7  40.4     1.1      M    M
  9250   -9.4  15.1   255    3    2   4.7   2.6    4.2  39.6     0.6      M    M
  9000   -9.0  15.8   230    2    1   6.2   3.4    3.9  39.0     0.2      M    M
  8750   -8.6  16.5   180    2    1   5.8   3.2    3.6  38.5    -0.0    260  1.3
  8500   -8.2  17.2   140    3    1   5.2   2.9    3.3  37.9    -0.4    242  1.2
  8250   -7.9  17.8   130    4    2   4.4   2.4    2.9  37.2    -0.8    224  1.1
  8000   -7.6  18.3   120    6    3   3.5   1.9    2.4  36.4    -1.2    209  1.1
  7750   -7.3  18.9   120    6    3   3.7   2.0    1.9  35.5    -1.7    193  1.0
  7500   -7.0  19.4   120    7    4   3.7   2.0    1.5  34.6    -2.2    177  0.9
  7250   -6.8  19.8   120    7    4   3.6   2.0    1.0  33.8    -2.6    162  0.8
  7000   -6.5  20.3   120    8    4   4.0   2.2    0.5  33.0    -3.1    146  0.7
  6750   -6.1  21.0   115    8    4   6.7   3.7    0.2  32.3    -3.4    127  0.6
  6500   -5.5  22.1   115    8    4   8.3   4.6    0.0  32.1    -3.6    102  0.5
  6250   -4.9  23.2   110    7    4   7.7   4.2   -0.1  31.8    -3.7     76  0.4
  6000   -4.3  24.3   105    7    4   8.4   4.6   -0.2  31.6    -3.9     51  0.3
  5750   -3.7  25.3   105    6    3   6.2   3.4   -0.4  31.4    -4.0     25  0.1
  5500   -3.4  25.9   100    6    3   1.9   1.1   -0.8  30.5    -4.5     10  0.0
  5250   -3.3  26.1   100    5    3   2.9   1.6   -1.4  29.5    -5.1      M    M
  5000   -3.1  26.4   095    4    2  -2.5  -1.4   -2.0  28.4    -5.7      M    M

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

           12/03/2016 at 0800 MST          |       12/03/2016 at 1100 MST
                                           |
K index... -16.7  LI... +11.3              | K index... -0.3  LI... +10.4
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... M
                                           |
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 -60.1 -76.2  295  26 14   2.2   1.2 | -61.1 -78.0  300  32 16   1.3   0.7
 45000 -56.8 -70.2  310  31 16   2.1   1.1 | -59.1 -74.4  310  41 21   1.5   0.8
 40000 -55.0 -67.0  320  38 19   1.2   0.7 | -55.4 -67.7  330  49 25   2.5   1.4
 38000 -53.9 -65.0  330  43 22   2.6   1.4 | -53.9 -65.0  340  59 30   2.5   1.4
 36000 -52.2 -62.0  345  58 30   2.6   1.4 | -52.2 -62.0  350  77 40   2.5   1.4
 34000 -50.5 -58.9  350  71 37   5.7   3.1 | -50.4 -58.7  350  91 47   7.1   3.9
 32000 -47.2 -53.0  350  65 33   5.5   3.0 | -46.5 -51.7  350  86 44   6.6   3.6
 30000 -43.9 -47.0  345  58 30   6.3   3.5 | -42.6 -44.7  345  80 41   6.1   3.3
 29000 -42.0 -43.6  345  51 26   6.2   3.4 | -40.7 -41.3  345  75 38   6.1   3.3
 28000 -40.2 -40.4  345  45 23   6.2   3.4 | -38.9 -38.0  345  70 36   6.1   3.3
 27000 -38.3 -36.9  345  38 20   6.1   3.3 | -37.1 -34.8  345  65 33   6.1   3.4
 26000 -36.2 -33.2  340  34 18   7.4   4.1 | -35.3 -31.5  345  58 30   5.7   3.1
 25000 -34.0 -29.2  335  32 17   7.4   4.1 | -33.6 -28.5  340  50 26   5.7   3.2
 24000 -31.8 -25.2  330  30 16   7.4   4.1 | -31.9 -25.4  340  43 22   5.7   3.1
 23000 -29.7 -21.5  325  29 15   6.7   3.7 | -30.0 -22.0  335  38 20   6.6   3.6
 22000 -27.7 -17.9  325  28 14   6.7   3.7 | -28.0 -18.4  330  35 18   6.6   3.6
 21000 -25.7 -14.3  320  27 14   6.7   3.7 | -26.1 -15.0  320  33 17   6.6   3.6
 20000 -23.3  -9.9  325  28 14   6.7   3.7 | -23.7 -10.7  320  31 16   6.4   3.5
 19500 -22.3  -8.1  325  29 15   6.7   3.7 | -22.7  -8.9  315  30 16   6.4   3.5
 19000 -21.3  -6.3  330  29 15   6.8   3.7 | -21.8  -7.2  315  30 15   6.4   3.5
 18500 -20.3  -4.5  330  30 15   7.6   4.2 | -20.8  -5.4  310  29 15   6.6   3.6
 18000 -19.0  -2.2  330  29 15   8.7   4.8 | -19.8  -3.6  310  28 15   6.8   3.7
 17500 -17.7   0.1  330  28 15   9.1   5.0 | -18.8  -1.8  315  27 14   6.9   3.8
 17000 -16.8   1.8  330  27 14   3.6   2.0 | -17.8  -0.0  315  26 14   6.3   3.5
 16500 -16.1   3.0  325  25 13   4.1   2.3 | -16.9   1.6  315  25 13   6.5   3.6
 16000 -15.4   4.3  325  24 12   5.0   2.8 | -16.0   3.2  315  24 12   5.5   3.0
 15500 -14.6   5.7  320  23 12   5.3   2.9 | -15.3   4.5  315  22 12   5.3   2.9
 15000 -13.7   7.3  315  22 11   4.8   2.7 | -14.6   5.7  315  21 11   5.2   2.9
 14500 -13.1   8.4  310  21 11   4.1   2.3 | -13.8   7.2  315  20 10   5.0   2.8
 14000 -12.5   9.5  305  20 10   3.7   2.0 | -13.0   8.6  315  19 10   4.3   2.4
 13500 -12.1  10.2  305  19 10   2.2   1.2 | -12.5   9.5  315  18  9   2.6   1.4
 13000 -11.7  10.9  300  19 10   2.1   1.2 | -12.1  10.2  315  17  9   2.5   1.4
 12500 -11.5  11.3  300  18  9   1.3   0.7 | -11.8  10.8  310  16  8   1.7   0.9
 12000 -11.3  11.7  300  16  8   1.4   0.8 | -11.5  11.3  310  15  8   1.7   1.0
 11500 -11.0  12.2  300  15  8   2.2   1.2 | -11.2  11.8  310  13  7   1.8   1.0
 11000 -10.7  12.7  295  14  7   2.3   1.3 | -11.0  12.2  310  12  6   2.2   1.2
 10500 -10.3  13.5  295  12  6   2.9   1.6 | -10.6  12.9  310  10  5   2.9   1.6
 10250 -10.1  13.8  295  11  6   3.5   1.9 | -10.3  13.5  310   9  5   3.3   1.8
 10000  -9.9  14.2  295  10  5   1.5   0.8 | -10.1  13.8  310   8  4   1.7   0.9
  9750  -9.9  14.2  295   9  5   1.9   1.0 | -10.0  14.0  310   7  4   3.0   1.6
  9500  -9.6  14.7  295   8  4   4.3   2.3 |  -9.7  14.5  310   6  3   5.5   3.0
  9250  -9.4  15.1  295   7  4   3.7   2.0 |  -9.3  15.3  305   6  3   4.8   2.6
  9000  -9.1  15.6  295   6  3   3.6   2.0 |  -9.0  15.8  300   5  2   4.3   2.4
  8750  -8.9  16.0  290   5  2   3.7   2.0 |  -8.7  16.3  300   4  2   4.7   2.6
  8500  -8.6  16.5  290   4  2   4.0   2.2 |  -8.3  17.1  290   3  2   5.6   3.1
  8250  -8.3  17.1  285   2  1   4.2   2.3 |  -7.9  17.8  275   2  1   5.2   2.8
  8000  -8.0  17.6  280   2  1   4.2   2.3 |  -7.5  18.5  260   2  1   4.6   2.5
  7750  -7.7  18.1  275   1  0   5.1   2.8 |  -7.2  19.0  245   1  1   5.2   2.9
  7500  -7.3  18.9  000   0  0   5.9   3.2 |  -6.8  19.8  225   1  1   5.6   3.1
  7250  -6.9  19.6  000   0  0   4.7   2.6 |  -6.4  20.5  205   1  1   4.8   2.6
  7000  -6.5  20.3  130   1  1   4.0   2.2 |  -6.1  21.0  190   1  1   4.5   2.5
  6750  -6.2  20.8  130   2  1   4.5   2.4 |  -5.7  21.7  180   2  1   4.3   2.3
  6500  -5.9  21.4  135   3  1   3.1   1.7 |  -5.4  22.3  180   2  1   6.0   3.3
  6250  -5.8  21.6  135   3  2   1.8   1.0 |  -4.9  23.2  180   2  1   7.9   4.3
  6000  -5.6  21.9  130   4  2   2.5   1.4 |  -4.4  24.1  185   2  1   6.5   3.6
  5750  -5.5  22.1  130   4  2   0.8   0.5 |  -3.8  25.2  185   2  1  10.5   5.7
  5500  -5.6  21.9  120   4  2  -3.7  -2.0 |  -2.7  27.1  180   2  1  19.4  10.6
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           12/03/2016 at 1400 MST          |       12/03/2016 at 1700 MST
                                           |
K index... -12.5  LI... +10.2              | K index... -26.1  LI... +10.1
CAPE... 0.0  CIN... -1.4                   | CAPE... 0.0  CIN... M
                                           |
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 -61.0 -77.8  310  34 17   1.3   0.7 | -61.2 -78.2  320  45 23   0.9   0.5
 45000 -59.0 -74.2  325  49 25   1.6   0.9 | -59.8 -75.6  330  58 30   1.4   0.8
 40000 -55.0 -67.0  335  65 34   2.7   1.5 | -56.0 -68.8  335  72 37   2.5   1.4
 38000 -53.4 -64.1  340  73 37   2.5   1.4 | -54.2 -65.6  340  78 40   3.4   1.9
 36000 -51.9 -61.4  345  81 42   2.5   1.4 | -52.2 -62.0  350  86 44   3.4   1.9
 34000 -49.9 -57.8  350  90 46   6.2   3.4 | -50.1 -58.2  355  94 48   4.7   2.6
 32000 -46.4 -51.5  350  92 47   5.8   3.2 | -46.6 -51.9  350  95 49   5.2   2.9
 30000 -42.9 -45.2  345  93 48   6.2   3.4 | -43.3 -45.9  345  94 48   6.6   3.6
 29000 -41.0 -41.8  350  90 46   6.2   3.4 | -41.4 -42.5  350  90 46   6.5   3.6
 28000 -39.2 -38.6  350  87 45   6.2   3.4 | -39.4 -38.9  350  86 44   6.5   3.6
 27000 -37.3 -35.1  350  84 43   6.1   3.4 | -37.5 -35.5  355  82 42   6.6   3.6
 26000 -35.0 -31.0  355  84 43   8.3   4.5 | -35.2 -31.4  355  80 41   7.8   4.3
 25000 -32.5 -26.5  355  84 43   8.3   4.5 | -32.9 -27.2  355  79 41   7.8   4.3
 24000 -30.0 -22.0  355  84 43   8.4   4.6 | -30.5 -22.9  360  78 40   7.8   4.3
 23000 -27.9 -18.2  355  76 39   6.3   3.4 | -28.1 -18.6  355  72 37   7.9   4.3
 22000 -26.0 -14.8  350  65 33   6.3   3.4 | -25.8 -14.4  355  65 33   7.9   4.3
 21000 -24.1 -11.4  345  53 27   6.0   3.3 | -23.4 -10.1  350  58 30   7.4   4.0
 20000 -22.9  -9.2  340  45 23   3.7   2.0 | -21.7  -7.1  345  54 28   5.4   3.0
 19500 -22.3  -8.1  340  42 22   3.7   2.0 | -20.9  -5.6  345  52 27   5.4   3.0
 19000 -21.8  -7.2  335  38 20   3.7   2.0 | -20.1  -4.2  345  51 26   5.4   3.0
 18500 -21.2  -6.2  335  35 18   3.5   1.9 | -19.2  -2.6  340  49 25   5.4   3.0
 18000 -20.4  -4.7  330  33 17   6.9   3.8 | -18.6  -1.5  340  47 24   3.6   2.0
 17500 -19.4  -2.9  330  32 16   6.6   3.6 | -18.0  -0.4  340  44 22   3.7   2.0
 17000 -18.4  -1.1  330  30 16   7.8   4.3 | -17.4   0.7  340  41 21   5.3   2.9
 16500 -17.2   1.0  330  29 15   8.2   4.5 | -16.5   2.3  340  40 21   5.8   3.2
 16000 -15.9   3.4  330  28 14   7.0   3.8 | -15.6   3.9  345  40 20   5.2   2.9
 15500 -15.1   4.8  325  25 13   3.5   1.9 | -15.0   5.0  345  38 19   3.8   2.1
 15000 -14.6   5.7  320  23 12   3.4   1.8 | -14.1   6.6  340  34 18   2.7   1.5
 14500 -14.1   6.6  320  21 11   3.3   1.8 | -13.8   7.2  340  31 16   2.3   1.3
 14000 -13.7   7.3  320  19 10   3.1   1.7 | -13.5   7.7  335  28 15   2.3   1.3
 13500 -13.3   8.1  320  17  9   2.6   1.4 | -13.2   8.2  335  25 13   2.4   1.3
 13000 -12.9   8.8  320  15  8   2.5   1.3 | -12.9   8.8  335  22 11   2.8   1.5
 12500 -12.6   9.3  325  13  7   2.1   1.2 | -12.5   9.5  340  19 10   3.3   1.8
 12000 -12.2  10.0  330  12  6   2.4   1.3 | -12.0  10.4  350  17  9   4.0   2.2
 11500 -11.8  10.8  330  10  5   3.1   1.7 | -11.3  11.7  355  16  8   5.2   2.8
 11000 -11.3  11.7  335   9  5   3.6   2.0 | -10.5  13.1  360  17  9   4.6   2.5
 10500 -10.7  12.7  335   8  4   4.2   2.3 |  -9.9  14.2  010  14  7   4.1   2.3
 10250 -10.4  13.3  335   8  4   3.6   2.0 |  -9.6  14.7  015  13  7   3.4   1.8
 10000 -10.1  13.8  335   7  4   3.0   1.6 |  -9.4  15.1  020  13  6   3.0   1.7
  9750  -9.9  14.2  335   7  4   5.1   2.8 |  -9.1  15.6  025  11  6   5.0   2.7
  9500  -9.4  15.1  340   6  3   6.7   3.7 |  -8.7  16.3  030  10  5   6.1   3.3
  9250  -9.0  15.8  340   6  3   5.7   3.1 |  -8.2  17.2  040   8  4   5.6   3.1
  9000  -8.6  16.5  340   5  3   4.8   2.6 |  -7.8  18.0  045   7  4   5.6   3.1
  8750  -8.2  17.2  345   5  3   5.8   3.2 |  -7.4  18.7  045   6  3   6.3   3.5
  8500  -7.7  18.1  345   4  2   6.7   3.7 |  -6.9  19.6  050   6  3   6.9   3.8
  8250  -7.2  19.0  350   3  2   6.4   3.5 |  -6.4  20.5  055   5  3   5.6   3.1
  8000  -6.8  19.8  350   3  1   6.4   3.5 |  -6.0  21.2  050   4  2   4.7   2.6
  7750  -6.3  20.7  355   2  1   6.5   3.6 |  -5.6  21.9  045   4  2   5.0   2.8
  7500  -5.8  21.6  350   2  1   6.1   3.3 |  -5.3  22.5  040   3  2   5.1   2.8
  7250  -5.4  22.3  340   1  1   5.5   3.0 |  -4.9  23.2  035   3  1   5.2   2.9
  7000  -5.0  23.0  325   1  1   5.3   2.9 |  -4.5  23.9  025   2  1   5.2   2.9
  6750  -4.6  23.7  315   2  1   5.5   3.0 |  -4.1  24.6  015   2  1   5.0   2.7
  6500  -4.2  24.4  305   2  1   7.4   4.1 |  -3.8  25.2  355   2  1   4.5   2.5
  6250  -3.6  25.5  305   2  1   8.7   4.8 |  -3.5  25.7  330   2  1   4.6   2.5
  6000  -3.0  26.6  305   2  1   8.2   4.5 |  -3.2  26.2  305   2  1   4.0   2.2
  5750  -2.4  27.7  300   2  1   8.3   4.5 |  -3.0  26.6  285   2  1   2.5   1.4
  5500  -1.8  28.8  300   2  1   8.5   4.7 |  -2.9  26.8  285   2  1   2.1   1.2
  5250  -1.2  29.8  300   2  1   8.3   4.6 |  -2.7  27.1  285   2  1   2.4   1.3
  5000     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 at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  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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