Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 191300
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0700 MDT Tuesday, September 19, 2017

This forecast is for Tuesday, September 19, 2017:

If the trigger temperature of 73.8 F/23.2 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 711 ft/min (3.6 m/s)
   Maximum height of thermals.................. 13537 ft MSL (8698 ft AGL)

Forecast maximum temperature................... 81.0 F/27.7 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 10074 ft MSL (5235 ft AGL)
Thermal soaring outlook for Wednesday 09/20.... Good

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

Remarks...

Sunrise/Sunset.................... 06:59:22 / 19:17:01 MDT
Total possible sunshine........... 12 hr 17 min 40 sec (737 min 40 sec)
Altitude of sun at 13:07:42 MDT... 52.07 degrees

Upper air data from rawinsonde observation taken on 09/19/2017 at 0600 MDT

Freezing level.................. 14210 ft MSL (9371 ft AGL)
Convective condensation level... 22642 ft MSL (17803 ft AGL)
Lifted condensation level....... 18913 ft MSL (14074 ft AGL)
Lifted index.................... +6.3
K index......................... -6.3

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  -60.7 -77.3   250   54   28   0.8   0.4   96.6 205.8    39.8      M    M
 45000  -61.0 -77.8   255   63   32  -9.4  -5.1   70.3 158.5    26.6      M    M
 40000  -59.7 -75.5   270   68   35   8.8   4.8   49.3 120.8    14.6      M    M
 38000  -54.8 -66.6   265   70   36   8.1   4.4   47.8 118.0    14.0      M    M
 36000  -49.7 -57.5   265   69   36   8.7   4.8   46.7 116.1    13.6      M    M
 34000  -44.4 -47.9   260   69   35   8.3   4.5   46.0 114.8    13.4      M    M
 32000  -39.0 -38.2   255   69   35   8.1   4.4   44.4 111.8    12.6      M    M
 30000  -34.1 -29.4   255   72   37   7.9   4.3   43.3 109.9    12.1      M    M
 29000  -31.6 -24.9   255   71   36   8.4   4.6   42.5 108.5    11.6      M    M
 28000  -29.1 -20.4   255   69   36   8.4   4.6   41.8 107.3    11.3      M    M
 27000  -26.6 -15.9   255   68   35   8.4   4.6   41.3 106.4    11.0      M    M
 26000  -24.0 -11.2   255   66   34   8.4   4.6   41.0 105.7    10.8      M    M
 25000  -21.5  -6.7   255   65   33   8.5   4.7   40.7 105.2    10.7      M    M
 24000  -19.1  -2.4   255   63   33   3.8   2.1   40.0 104.0    10.3      M    M
 23000  -17.5   0.5   250   62   32   8.8   4.8   38.5 101.2     9.1      M    M
 22000  -14.8   5.4   245   61   32   8.3   4.6   38.1 100.6     8.9      M    M
 21000  -12.9   8.8   240   61   31   6.1   3.3   36.9  98.5     8.1      M    M
 20000  -11.7  10.9   235   61   31   6.0   3.3   34.9  94.9     6.4      M    M
 19500  -10.8  12.6   235   60   31   6.3   3.5   34.3  93.8     5.9      M    M
 19000   -9.9  14.2   235   59   31   5.7   3.1   33.7  92.7     5.3      M    M
 18500   -9.0  15.8   235   59   30   7.6   4.2   33.1  91.7     4.8      M    M
 18000   -7.8  18.0   235   59   30   7.6   4.2   32.8  91.0     4.6      M    M
 17500   -6.1  21.0   235   54   28   7.3   4.0   32.2  90.0     4.1      M    M
 17000   -5.3  22.5   235   51   26   3.5   1.9   31.4  88.5     3.5      M    M
 16500   -4.7  23.5   230   47   24   3.8   2.1   30.4  86.7     2.7      M    M
 16000   -4.1  24.6   230   44   22   3.5   1.9   29.4  85.0     1.8      M    M
 15500   -3.2  26.2   230   42   21   8.3   4.6   28.8  83.8     1.2      M    M
 15000   -2.0  28.4   230   40   20   8.8   4.8   28.6  83.4     1.0      M    M
 14500   -0.6  30.9   235   38   19   8.7   4.8   28.4  83.1     0.9      M    M
 14000    0.7  33.3   235   36   18   7.0   3.8   28.3  82.9     0.8      M    M
 13500    1.1  34.0   235   35   18   1.7   0.9   27.1  80.8    -0.2    708  3.6
 13000    1.9  35.4   235   34   18   8.1   4.4   26.4  79.6    -0.9    669  3.4
 12500    3.1  37.6   235   34   17   7.7   4.2   26.1  79.0    -1.2    620  3.2
 12000    4.2  39.6   235   33   17   7.7   4.2   25.8  78.4    -1.6    572  2.9
 11500    5.3  41.5   235   29   15   7.7   4.2   25.4  77.8    -1.9    524  2.7
 11000    6.4  43.5   235   25   13   7.7   4.2   25.1  77.2    -2.3    475  2.4
 10500    7.5  45.5   235   20   11   8.0   4.4   24.8  76.6    -2.7    427  2.2
 10250    8.1  46.6   235   18    9   7.0   3.8   24.6  76.3    -2.8    403  2.0
 10000    8.6  47.5   240   16    8   6.9   3.8   24.4  75.9    -3.1    381  1.9
  9750    9.1  48.4   240   16    8   7.9   4.3   24.2  75.6    -3.2    357  1.8
  9500    9.7  49.5   240   16    8   7.6   4.2   24.1  75.3    -3.4    332  1.7
  9250   10.3  50.5   240   17    9   7.7   4.2   23.9  75.1    -3.5    308  1.6
  9000   10.9  51.6   240   17    9   7.7   4.2   23.8  74.8    -3.7    283  1.4
  8750   11.4  52.5   240   17    9   7.7   4.2   23.6  74.5    -3.9    259  1.3
  8500   12.0  53.6   235   17    9   7.7   4.2   23.5  74.2    -4.0    234  1.2
  8250   12.6  54.7   235   17    9   7.7   4.2   23.3  74.0    -4.2    210  1.1
  8000   13.1  55.6   230   17    9   7.7   4.2   23.2  73.7    -4.4    185  0.9
  7750   13.7  56.7   220   17    9   7.7   4.2   23.0  73.4    -4.5    161  0.8
  7500   14.3  57.7   215   18    9   7.7   4.2   22.8  73.1    -4.7    136  0.7
  7250   14.9  58.8   205   18    9   7.7   4.2   22.7  72.8    -4.9    112  0.6
  7000   15.4  59.7   195   20   10   7.7   4.2   22.5  72.5    -5.0     87  0.4
  6750   16.0  60.8   195   20   10   7.7   4.2   22.4  72.2    -5.2     63  0.3
  6500   16.6  61.9   190   19   10   7.7   4.2   22.2  71.9    -5.4     38  0.2
  6250   17.1  62.8   190   19   10   7.7   4.2   22.0  71.6    -5.6     14  0.1
  6000   17.7  63.9   185   19   10   7.5   4.1   21.9  71.4    -5.8      M    M
  5750   18.3  64.9   180   16    8   8.5   4.7   21.7  71.1    -5.9      M    M
  5500   18.8  65.8   175   13    7   4.6   2.5   21.5  70.8    -6.1      M    M
  5250   18.9  66.0   165    9    5   0.3   0.2   20.9  69.6    -6.8      M    M
  5000   18.8  65.8   140    7    3  -4.4  -2.4   20.1  68.2    -7.6      M    M

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

           09/19/2017 at 0900 MDT          |       09/19/2017 at 1200 MDT
                                           |
K index... -2.0  LI... +7.4                | K index... +10.4  LI... +7.4
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -62.3 -80.1  260  56 29  -1.2  -0.7 | -63.1 -81.6  260  59 31  -2.3  -1.3
 45000 -63.1 -81.6  265  71 37   2.9   1.6 | -65.2 -85.4  265  78 40   4.4   2.4
 40000 -58.8 -73.8  280  75 38   4.8   2.6 | -58.2 -72.8  270  80 41   5.9   3.3
 38000 -54.1 -65.4  275  74 38   7.9   4.4 | -53.6 -64.5  270  79 41   7.8   4.3
 36000 -49.3 -56.7  270  73 38   7.9   4.4 | -48.9 -56.0  270  79 41   7.8   4.3
 34000 -44.3 -47.7  265  73 38   8.6   4.7 | -44.0 -47.2  270  79 41   8.3   4.6
 32000 -39.2 -38.6  265  73 38   8.6   4.7 | -39.0 -38.2  265  79 41   8.3   4.6
 30000 -34.1 -29.4  265  74 38   8.5   4.6 | -34.0 -29.2  265  79 41   8.6   4.7
 29000 -30.9 -23.6  265  74 38   8.5   4.6 | -30.7 -23.3  265  78 40   8.6   4.7
 28000 -28.4 -19.1  265  74 38   8.6   4.7 | -28.2 -18.8  265  77 40   8.7   4.7
 27000 -26.1 -15.0  260  73 38   7.3   4.0 | -25.8 -14.4  265  76 39   7.8   4.3
 26000 -23.9 -11.0  260  71 37   7.3   4.0 | -23.5 -10.3  265  75 39   7.8   4.3
 25000 -21.7  -7.1  260  70 36   7.4   4.0 | -21.2  -6.2  265  74 38   7.8   4.3
 24000 -19.5  -3.1  260  68 35   7.9   4.3 | -18.9  -2.0  265  73 37   7.6   4.2
 23000 -17.1   1.2  255  66 34   7.9   4.3 | -16.6   2.1  260  71 37   7.6   4.2
 22000 -14.7   5.5  255  65 33   7.8   4.3 | -14.3   6.3  260  70 36   7.6   4.2
 21000 -12.7   9.1  250  63 33   6.1   3.4 | -12.1  10.2  255  69 35   7.4   4.1
 20000 -10.9  12.4  250  62 32   6.1   3.3 |  -9.9  14.2  255  68 35   7.4   4.1
 19500  -9.9  14.2  245  61 31   6.1   3.3 |  -8.8  16.2  255  68 35   7.5   4.1
 19000  -9.0  15.8  245  60 31   6.1   3.3 |  -7.7  18.1  250  67 35   7.5   4.1
 18500  -8.1  17.4  245  59 30   6.3   3.5 |  -6.7  19.9  250  67 34   5.6   3.1
 18000  -7.2  19.0  240  58 30   6.3   3.5 |  -5.9  21.4  250  66 34   5.7   3.1
 17500  -6.3  20.7  240  57 29   6.1   3.4 |  -5.1  22.8  250  65 34   5.0   2.8
 17000  -5.4  22.3  240  55 28   6.0   3.3 |  -4.4  24.1  245  64 33   4.5   2.4
 16500  -4.5  23.9  240  54 28   6.0   3.3 |  -3.8  25.2  245  63 32   4.5   2.4
 16000  -3.6  25.5  240  53 27   4.9   2.7 |  -3.3  26.1  245  61 31   2.8   1.6
 15500  -2.8  27.0  235  51 26   5.2   2.8 |  -2.9  26.8  245  58 30   3.1   1.7
 15000  -2.2  28.0  235  49 25   3.0   1.6 |  -2.5  27.5  240  56 29   1.3   0.7
 14500  -1.8  28.8  235  47 24   2.7   1.5 |  -2.4  27.7  240  52 27   1.0   0.6
 14000  -1.2  29.8  235  44 23   2.6   1.4 |  -2.2  28.0  240  46 24   2.7   1.5
 13500  -0.9  30.4  235  42 22   2.5   1.4 |  -1.9  28.6  240  42 22   2.2   1.2
 13000  -0.5  31.1  235  40 21   4.9   2.7 |  -1.3  29.7  235  38 20   7.1   3.9
 12500   0.2  32.4  240  39 20   4.9   2.7 |  -0.2  31.6  235  36 18   7.4   4.1
 12000   1.0  33.8  240  38 19   7.3   4.0 |   1.0  33.8  235  33 17   8.8   4.8
 11500   2.2  36.0  240  37 19   7.7   4.2 |   2.3  36.1  235  31 16   9.2   5.0
 11000   3.3  37.9  240  36 19   7.9   4.4 |   3.7  38.7  235  30 15   8.4   4.6
 10500   4.5  40.1  235  36 18   7.5   4.1 |   4.9  40.8  235  27 14   8.5   4.7
 10250   5.1  41.2  235  35 18  11.4   6.3 |   5.6  42.1  235  26 13  11.5   6.3
 10000   6.1  43.0  235  35 18  12.2   6.7 |   6.5  43.7  235  26 13  11.2   6.2
  9750   6.9  44.4  235  35 18   9.2   5.0 |   7.3  45.1  235  25 13   9.2   5.1
  9500   7.6  45.7  235  34 18  10.4   5.7 |   8.0  46.4  235  25 13   9.8   5.4
  9250   8.4  47.1  235  34 18   8.4   4.6 |   8.7  47.7  235  24 13   9.7   5.3
  9000   8.9  48.0  235  34 17   8.3   4.5 |   9.4  48.9  235  24 12   9.5   5.2
  8750   9.6  49.3  235  33 17  10.1   5.5 |  10.1  50.2  240  24 12   9.6   5.2
  8500  10.4  50.7  235  32 17   9.4   5.2 |  10.8  51.4  240  23 12   9.0   4.9
  8250  11.1  52.0  235  32 16  10.3   5.7 |  11.6  52.9  240  23 12  11.2   6.1
  8000  11.8  53.2  230  31 16   8.1   4.4 |  12.5  54.5  240  23 12  11.2   6.1
  7750  12.3  54.1  230  30 16   5.7   3.1 |  13.2  55.8  240  22 12   9.0   5.0
  7500  12.8  55.0  225  30 15   5.8   3.2 |  13.9  57.0  240  22 11   9.6   5.2
  7250  13.1  55.6  225  29 15   2.0   1.1 |  14.6  58.3  240  22 11  10.1   5.5
  7000  13.1  55.6  215  26 14  -1.2  -0.7 |  15.4  59.7  240  21 11  10.4   5.7
  6750  13.0  55.4  210  24 12  -2.7  -1.5 |  16.1  61.0  240  21 11   9.7   5.3
  6500  12.8  55.0  200  21 11  -1.2  -0.7 |  16.9  62.4  240  21 11  10.2   5.6
  6250  12.8  55.0  195  18  9   1.5   0.8 |  17.7  63.9  240  20 10  11.1   6.1
  6000  12.9  55.2  190  16  8   2.7   1.5 |  18.5  65.3  240  19 10  11.7   6.4
  5750  13.3  55.9  185  14  7   6.4   3.5 |  19.4  66.9  240  18  9  12.0   6.6
  5500  13.8  56.8  180  12  6   8.6   4.7 |  20.3  68.5  240  17  9  13.8   7.6
  5250  14.5  58.1  180  11  6   7.4   4.0 |  21.5  70.7  240  17  9  16.7   9.2
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           09/19/2017 at 1500 MDT          |       09/19/2017 at 1800 MDT
                                           |
K index... +15.4  LI... +4.1               | K index... +21.4  LI... +2.1
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -61.7 -79.1  270  57 29  -0.9  -0.5 | -63.5 -82.3  285  57 29  -1.7  -0.9
 45000 -62.4 -80.3  270  68 35   2.5   1.4 | -64.7 -84.5  290  79 41   4.7   2.6
 40000 -58.4 -73.1  280  87 45   5.0   2.7 | -57.2 -71.0  285  90 46   6.1   3.4
 38000 -53.7 -64.7  275  86 44   7.9   4.3 | -52.7 -62.9  280  85 44   7.5   4.1
 36000 -49.0 -56.2  275  85 44   7.9   4.3 | -48.3 -54.9  275  80 41   7.5   4.1
 34000 -44.0 -47.2  270  81 42   8.5   4.6 | -43.4 -46.1  270  78 40   8.5   4.7
 32000 -39.0 -38.2  270  75 39   8.5   4.6 | -38.3 -36.9  270  77 40   8.5   4.7
 30000 -34.0 -29.2  275  73 38   8.1   4.4 | -33.3 -27.9  270  76 39   8.3   4.5
 29000 -31.6 -24.9  275  74 38   8.1   4.4 | -30.2 -22.4  270  76 39   8.3   4.5
 28000 -28.6 -19.5  275  74 38   8.1   4.5 | -27.7 -17.9  270  75 39   8.4   4.6
 27000 -26.3 -15.3  275  75 39   7.6   4.2 | -25.6 -14.1  270  72 37   6.8   3.7
 26000 -24.0 -11.2  270  76 39   7.7   4.2 | -23.5 -10.3  265  67 35   6.8   3.7
 25000 -21.7  -7.1  270  77 39   7.7   4.2 | -21.5  -6.7  260  63 32   6.8   3.7
 24000 -19.5  -3.1  265  76 39   7.1   3.9 | -19.5  -3.1  260  61 32   6.4   3.5
 23000 -17.4   0.7  265  74 38   7.1   3.9 | -17.6   0.3  265  64 33   6.4   3.5
 22000 -15.3   4.5  260  73 37   7.1   3.9 | -15.7   3.7  265  67 35   6.4   3.5
 21000 -13.2   8.2  260  71 36   6.7   3.7 | -13.8   7.2  265  68 35   6.4   3.5
 20000 -11.2  11.8  260  68 35   6.7   3.7 | -11.9  10.6  265  65 33   6.4   3.5
 19500 -10.2  13.6  260  67 34   6.7   3.7 | -11.0  12.2  265  63 33   6.4   3.5
 19000  -9.2  15.4  255  65 34   6.7   3.7 | -10.0  14.0  265  62 32   6.4   3.5
 18500  -8.3  17.1  255  64 33   5.9   3.2 |  -9.2  15.4  265  60 31   5.5   3.0
 18000  -7.4  18.7  255  63 32   5.9   3.3 |  -8.3  17.1  265  58 30   5.6   3.1
 17500  -6.6  20.1  255  61 32   5.5   3.0 |  -7.5  18.5  265  56 29   4.7   2.6
 17000  -5.8  21.6  255  60 31   5.2   2.9 |  -7.0  19.4  265  53 27   4.1   2.3
 16500  -5.1  22.8  255  58 30   5.2   2.8 |  -6.4  20.5  265  50 26   4.2   2.3
 16000  -4.4  24.1  255  56 29   4.3   2.4 |  -5.7  21.7  260  46 24   5.3   2.9
 15500  -3.8  25.2  250  53 27   4.4   2.4 |  -5.0  23.0  260  43 22   5.2   2.8
 15000  -3.1  26.4  250  51 26   5.3   2.9 |  -4.2  24.4  255  39 20   7.3   4.0
 14500  -2.4  27.7  245  48 24   5.4   3.0 |  -3.1  26.4  255  37 19   7.5   4.1
 14000  -1.6  29.1  240  45 23   5.7   3.1 |  -1.4  29.5  250  34 18   8.2   4.5
 13500  -0.4  31.3  240  40 21   5.6   3.1 |  -0.3  31.5  245  34 17   8.2   4.5
 13000   0.6  33.1  235  37 19   8.3   4.6 |   1.0  33.8  245  33 17   8.7   4.7
 12500   1.9  35.4  235  36 18   8.3   4.6 |   2.2  36.0  245  32 17   8.6   4.7
 12000   3.1  37.6  235  34 18   9.1   5.0 |   3.5  38.3  245  32 16   9.3   5.1
 11500   4.5  40.1  240  33 17   9.2   5.1 |   4.9  40.8  245  31 16   9.4   5.2
 11000   5.8  42.4  240  32 16   8.5   4.7 |   6.3  43.3  245  30 16   8.6   4.7
 10500   7.1  44.8  240  30 16   8.8   4.8 |   7.5  45.5  250  30 15   9.1   5.0
 10250   7.8  46.0  245  30 15  10.4   5.7 |   8.3  46.9  250  30 15  10.8   5.9
 10000   8.6  47.5  245  29 15  10.3   5.7 |   9.1  48.4  250  29 15  10.2   5.6
  9750   9.3  48.7  245  29 15   9.6   5.3 |   9.8  49.6  250  29 15   9.4   5.2
  9500  10.0  50.0  245  28 15   9.9   5.4 |  10.5  50.9  250  29 15   9.5   5.2
  9250  10.8  51.4  250  28 14   9.5   5.2 |  11.2  52.2  250  28 15   9.8   5.4
  9000  11.5  52.7  250  28 14   9.4   5.2 |  12.0  53.6  250  28 14   9.7   5.3
  8750  12.2  54.0  250  27 14   9.8   5.4 |  12.7  54.9  250  27 14   9.5   5.2
  8500  12.9  55.2  250  27 14   9.1   5.0 |  13.4  56.1  255  26 14   9.2   5.1
  8250  13.6  56.5  250  27 14  11.5   6.3 |  14.1  57.4  255  26 13  10.7   5.9
  8000  14.6  58.3  250  27 14  11.2   6.1 |  15.0  59.0  255  25 13  10.3   5.7
  7750  15.2  59.4  255  26 14   8.7   4.8 |  15.6  60.1  255  24 13   8.5   4.7
  7500  15.9  60.6  255  26 13   9.1   5.0 |  16.3  61.3  260  24 12   9.0   4.9
  7250  16.6  61.9  255  26 13  10.6   5.8 |  16.9  62.4  260  23 12   9.3   5.1
  7000  17.5  63.5  255  26 13  11.2   6.1 |  17.7  63.9  260  23 12   9.8   5.4
  6750  18.2  64.8  255  25 13   9.6   5.3 |  18.4  65.1  260  22 11   9.8   5.4
  6500  19.0  66.2  255  25 13  10.1   5.5 |  19.1  66.4  260  21 11   9.8   5.4
  6250  19.7  67.5  255  24 12  10.8   5.9 |  19.9  67.8  260  20 10  10.0   5.5
  6000  20.6  69.1  255  23 12  11.7   6.4 |  20.6  69.1  260  19 10   9.9   5.4
  5750  21.5  70.7  255  22 11  12.8   7.0 |  21.4  70.5  265  18  9  10.5   5.8
  5500  22.5  72.5  260  20 10  14.1   7.7 |  22.1  71.8  265  15  8   8.7   4.8
  5250  23.6  74.5  255  20 10  15.2   8.3 |  22.6  72.7  265  15  8   4.0   2.2
  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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