Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 241234
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0634 MDT Monday, April 24, 2017

This forecast is for Monday, April 24, 2017:

If the trigger temperature of 61.2 F/16.2 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 858 ft/min (4.4 m/s)
   Maximum height of thermals.................. 15209 ft MSL (10370 ft AGL)

Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 1000 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................. 13772 ft MSL (8933 ft AGL)
Thermal soaring outlook for Tuesday 04/25...... Good

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

Remarks...

Sunrise/Sunset.................... 06:24:28 / 19:59:42 MDT
Total possible sunshine........... 13 hr 35 min 14 sec (815 min 14 sec)
Altitude of sun at 13:12:15 MDT... 64.00 degrees

Upper air data from rawinsonde observation taken on 04/24/2017 at 0600 MDT

Freezing level.................. 10617 ft MSL (5778 ft AGL)
Convective condensation level... 13044 ft MSL (8205 ft AGL)
Lifted condensation level....... 14643 ft MSL (9804 ft AGL)
Lifted index.................... -0.3
K index......................... -2.6

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  -58.1 -72.6   235   39   20   3.5   1.9  104.8 220.6    47.0      M    M
 45000  -57.9 -72.2   280   51   26   6.8   3.7   80.3 176.6    35.4      M    M
 40000  -60.6 -77.1   280   61   32  -7.8  -4.3   52.8 127.1    20.0      M    M
 38000  -62.0 -79.6   275   71   36  -0.9  -0.5   40.8 105.4    12.5      M    M
 36000  -59.1 -74.4   280   67   34   8.6   4.7   36.4  97.5     9.8      M    M
 34000  -53.8 -64.8   280   63   32   8.5   4.6   35.5  95.9     9.4      M    M
 32000  -48.5 -55.3   275   57   29   9.1   5.0   34.7  94.5     9.1      M    M
 30000  -43.1 -45.6   275   53   27   9.3   5.1   34.2  93.6     9.0      M    M
 29000  -40.3 -40.5   275   54   28   9.3   5.1   34.0  93.2     8.9      M    M
 28000  -37.7 -35.9   275   55   28   7.6   4.2   33.6  92.5     8.7      M    M
 27000  -35.4 -31.7   270   56   29   7.7   4.2   32.8  91.0     8.2      M    M
 26000  -33.1 -27.6   270   57   29   8.2   4.5   32.1  89.8     7.7      M    M
 25000  -30.6 -23.1   270   58   30   8.3   4.5   31.6  88.9     7.4      M    M
 24000  -28.2 -18.8   270   53   27   7.1   3.9   31.0  87.7     7.0      M    M
 23000  -26.1 -15.0   270   51   26   7.1   3.9   29.9  85.9     6.2      M    M
 22000  -24.2 -11.6   270   51   26   5.8   3.2   28.7  83.6     5.2      M    M
 21000  -21.9  -7.4   275   50   26   7.5   4.1   27.8  82.0     4.6      M    M
 20000  -19.3  -2.7   275   48   25   4.0   2.2   26.5  79.8     3.6      M    M
 19500  -18.3  -0.9   275   45   23   9.0   4.9   26.0  78.8     3.2      M    M
 19000  -17.0   1.4   275   43   22   8.5   4.7   25.8  78.4     3.1      M    M
 18500  -16.3   2.7   275   40   21   0.6   0.3   24.9  76.8     2.3      M    M
 18000  -16.2   2.8   270   39   20   5.2   2.8   23.3  73.9     0.9      M    M
 17500  -14.9   5.2   270   38   19   8.7   4.8   23.1  73.6     0.8      M    M
 17000  -13.5   7.7   265   37   19   9.0   4.9   23.0  73.4     0.6      M    M
 16500  -12.2  10.0   265   36   18   9.0   4.9   22.9  73.2     0.5      M    M
 16000  -10.8  12.6   260   35   18   8.9   4.9   22.8  73.0     0.5      M    M
 15500   -9.5  14.9   255   36   19   7.3   4.0   22.6  72.7     0.3      M    M
 15000   -8.8  16.2   255   37   19   3.9   2.1   21.7  71.1    -0.5    841  4.3
 14500   -8.3  17.1   265   34   18   3.0   1.6   20.7  69.2    -1.5    812  4.1
 14000   -7.9  17.8   270   32   16   3.4   1.9   19.6  67.3    -2.6    785  4.0
 13500   -7.3  18.9   270   28   14   8.3   4.5   18.9  66.0    -3.4    750  3.8
 13000   -6.0  21.2   275   24   12   8.5   4.6   18.7  65.6    -3.6    697  3.5
 12500   -4.7  23.5   275   20   10   8.5   4.6   18.5  65.3    -3.8    645  3.3
 12000   -3.5  25.7   280   16    8   8.4   4.6   18.3  64.9    -4.0    592  3.0
 11500   -2.4  27.7   280   14    7   8.3   4.6   17.9  64.3    -4.5    546  2.8
 11000   -1.1  30.0   280   12    6   9.3   5.1   17.9  64.2    -4.6    490  2.5
 10500    0.3  32.5   285   10    5   8.1   4.4   17.8  64.1    -4.8    435  2.2
 10250    0.8  33.4   285    9    5   6.8   3.7   17.6  63.7    -5.0    411  2.1
 10000    1.3  34.3   285    8    4   7.4   4.1   17.4  63.3    -5.2    388  2.0
  9750    1.9  35.4   290    7    4   8.1   4.5   17.2  63.0    -5.3    363  1.8
  9500    2.5  36.5   290    8    4   8.4   4.6   17.1  62.8    -5.5    337  1.7
  9250    3.2  37.8   295    8    4   8.3   4.6   17.0  62.7    -5.6    311  1.6
  9000    3.8  38.8   300    9    5   8.3   4.6   17.0  62.5    -5.7    285  1.5
  8750    4.4  39.9   290   10    5   8.3   4.6   16.8  62.3    -5.8    260  1.3
  8500    5.0  41.0   285   12    6   8.3   4.6   16.7  62.1    -5.9    234  1.2
  8250    5.6  42.1   280   14    7   8.3   4.6   16.6  61.9    -6.1    208  1.1
  8000    6.3  43.3   275   17    9   8.3   4.6   16.5  61.8    -6.2    182  0.9
  7750    6.9  44.4   275   16    8   8.3   4.6   16.4  61.6    -6.3    156  0.8
  7500    7.5  45.5   270   15    8   8.3   4.6   16.3  61.4    -6.4    130  0.7
  7250    8.1  46.6   265   13    7   8.3   4.6   16.2  61.2    -6.6    104  0.5
  7000    8.7  47.7   260   12    6   8.3   4.6   16.1  61.0    -6.7     78  0.4
  6750    9.3  48.7   260   11    6   8.3   4.6   16.0  60.8    -6.8     52  0.3
  6500   10.0  50.0   265   10    5   8.3   4.6   15.9  60.6    -7.0     26  0.1
  6250   10.6  51.1   265    9    4   8.4   4.6   15.8  60.4    -7.1      0  0.0
  6000   11.2  52.2   270    7    4   8.3   4.6   15.7  60.2    -7.2      M    M
  5750   11.8  53.2   275    6    3   8.5   4.7   15.5  60.0    -7.4      M    M
  5500   12.4  54.3   290    4    2   7.8   4.3   15.4  59.8    -7.5      M    M
  5250   13.1  55.6   315    3    1  10.3   5.7   15.3  59.5    -7.7      M    M
  5000   13.7  56.7   355    3    1   1.0   0.5   15.2  59.3    -7.8      M    M

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

           04/24/2017 at 0900 MDT          |       04/24/2017 at 1200 MDT
                                           |
K index... +17.6  LI... +0.9               | K index... +21.8  LI... +0.8
CAPE... 0.0  CIN... 0.0                    | CAPE... +2.6  CIN... -28.2
                                           |
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 -59.6 -75.3  265  40 21   0.8   0.4 | -59.3 -74.7  265  45 23   1.3   0.7
 45000 -58.5 -73.3  275  41 21   0.9   0.5 | -57.4 -71.3  275  43 22   0.8   0.5
 40000 -61.2 -78.2  280  68 35  -1.8  -1.0 | -61.0 -77.8  280  75 39  -2.5  -1.4
 38000 -60.0 -76.0  280  74 38   5.3   2.9 | -60.3 -76.5  275  83 43   5.8   3.2
 36000 -56.8 -70.2  280  74 38   5.4   2.9 | -56.8 -70.2  275  85 44   5.8   3.2
 34000 -53.3 -63.9  280  74 38   8.9   4.9 | -52.3 -62.1  270  84 43   9.2   5.1
 32000 -48.1 -54.6  280  72 37   8.7   4.7 | -46.7 -52.1  270  77 40   9.4   5.1
 30000 -42.8 -45.0  280  70 36   9.5   5.2 | -41.2 -42.2  275  71 37   8.7   4.8
 29000 -40.0 -40.0  280  68 35   9.5   5.2 | -38.6 -37.5  275  69 36   8.7   4.8
 28000 -37.1 -34.8  275  66 34   9.6   5.2 | -36.0 -32.8  275  67 35   8.7   4.8
 27000 -34.3 -29.7  275  63 33   9.4   5.2 | -33.4 -28.1  275  65 34   8.2   4.5
 26000 -31.4 -24.5  275  60 31   7.4   4.1 | -31.1 -24.0  275  62 32   7.6   4.2
 25000 -29.2 -20.6  275  58 30   7.4   4.1 | -28.8 -19.8  275  58 30   7.6   4.2
 24000 -27.0 -16.6  270  55 28   7.1   3.9 | -26.6 -15.9  275  54 28   7.6   4.2
 23000 -25.2 -13.4  270  51 27   6.1   3.3 | -24.7 -12.5  270  52 27   6.1   3.4
 22000 -23.4 -10.1  270  48 25   6.1   3.3 | -22.8  -9.0  270  50 26   6.1   3.4
 21000 -21.6  -6.9  270  44 23   5.7   3.1 | -21.0  -5.8  265  49 25   6.1   3.3
 20000 -20.0  -4.0  265  43 22   5.4   3.0 | -19.3  -2.7  265  46 24   5.9   3.3
 19500 -19.2  -2.6  265  42 22   5.4   3.0 | -18.4  -1.1  265  45 23   6.0   3.3
 19000 -18.3  -0.9  265  41 21   5.5   3.0 | -17.5   0.5  265  44 23   5.9   3.3
 18500 -17.5   0.5  265  40 21   5.9   3.2 | -16.6   2.1  265  43 22   5.8   3.2
 18000 -16.6   2.1  265  40 21   6.8   3.7 | -15.9   3.4  265  41 21   4.6   2.5
 17500 -15.6   3.9  265  41 21   6.8   3.7 | -15.2   4.6  260  40 21   4.6   2.5
 17000 -14.6   5.7  265  41 21   7.3   4.0 | -14.4   6.1  260  39 20   6.3   3.5
 16500 -13.5   7.7  265  41 21   7.3   4.0 | -13.4   7.9  260  39 20   6.7   3.7
 16000 -12.5   9.5  265  41 21   7.2   4.0 | -11.9  10.6  255  38 19   8.1   4.5
 15500 -11.4  11.5  265  40 20   7.2   3.9 | -10.7  12.7  255  37 19   8.2   4.5
 15000 -10.3  13.5  265  39 20   7.3   4.0 |  -9.5  14.9  250  36 18   7.6   4.2
 14500  -9.2  15.4  265  37 19   7.9   4.3 |  -8.4  16.9  245  35 18   7.3   4.0
 14000  -8.0  17.6  265  35 18   7.9   4.3 |  -7.4  18.7  240  34 17   7.5   4.1
 13500  -6.9  19.6  265  33 17   7.5   4.1 |  -6.2  20.8  240  33 17   7.8   4.3
 13000  -5.2  22.6  265  29 15   7.6   4.1 |  -5.1  22.8  235  33 17   7.5   4.1
 12500  -4.1  24.6  265  27 14   7.6   4.2 |  -4.2  24.4  235  31 16   6.0   3.3
 12000  -2.9  26.8  260  24 12   7.5   4.1 |  -3.3  26.1  230  29 15   6.1   3.3
 11500  -1.8  28.8  260  22 11   7.4   4.1 |  -2.4  27.7  230  26 13   6.3   3.5
 11000  -0.7  30.7  255  19 10   7.0   3.9 |  -1.4  29.5  225  22 11   6.5   3.6
 10500   0.3  32.5  250  16  8   6.0   3.3 |  -0.3  31.5  220  19 10   7.8   4.3
 10250   0.7  33.3  250  15  7   7.1   3.9 |   0.3  32.5  215  18  9   8.9   4.9
 10000   1.2  34.2  250  13  7   7.4   4.1 |   1.0  33.8  215  17  9  10.2   5.6
  9750   1.7  35.1  245  12  6   6.2   3.4 |   1.8  35.2  215  17  9   9.8   5.4
  9500   2.1  35.8  245  11  6   6.2   3.4 |   2.5  36.5  215  16  8   9.9   5.4
  9250   2.5  36.5  240  10  5   6.6   3.6 |   3.3  37.9  215  16  8   9.6   5.3
  9000   3.0  37.4  240   9  5   6.5   3.6 |   3.9  39.0  215  15  8   8.7   4.8
  8750   3.4  38.1  235   8  4   6.3   3.4 |   4.6  40.3  210  14  7   8.6   4.7
  8500   3.9  39.0  230   8  4   6.0   3.3 |   5.2  41.4  210  13  6   8.7   4.7
  8250   4.3  39.7  225   7  4   7.3   4.0 |   5.9  42.6  205  11  6   9.2   5.1
  8000   4.9  40.8  225   7  3   8.3   4.5 |   6.6  43.9  200  10  5  10.2   5.6
  7750   5.4  41.7  220   6  3   6.9   3.8 |   7.3  45.1  200   9  5   9.7   5.3
  7500   5.9  42.6  220   6  3   6.7   3.7 |   8.0  46.4  200   9  5   9.3   5.1
  7250   6.4  43.5  220   6  3   6.3   3.4 |   8.7  47.7  200   9  4   9.3   5.1
  7000   6.8  44.2  220   5  3   5.5   3.0 |   9.4  48.9  200   8  4   9.4   5.2
  6750   7.2  45.0  220   4  2   5.4   3.0 |  10.1  50.2  200   8  4  10.0   5.5
  6500   7.6  45.7  210   3  2   5.6   3.1 |  10.9  51.6  200   8  4  10.1   5.5
  6250   8.1  46.6  205   3  1   7.3   4.0 |  11.7  53.1  200   8  4  10.2   5.6
  6000   8.7  47.7  195   3  1   8.5   4.7 |  12.4  54.3  200   7  4  10.6   5.8
  5750   9.4  48.9  190   3  1   9.3   5.1 |  13.2  55.8  200   7  4  10.4   5.7
  5500  10.1  50.2  185   2  1   9.1   5.0 |  14.0  57.2  200   7  3  12.3   6.7
  5250  10.7  51.3  190   2  1   7.0   3.8 |  15.1  59.2  200   7  3  17.4   9.5
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/24/2017 at 1500 MDT          |       04/24/2017 at 1800 MDT
                                           |
K index... +24.7  LI... +0.8               | K index... +24.7  LI... +0.2
CAPE... +0.2  CIN... -0.2                  | CAPE... +0.9  CIN... -28.9
                                           |
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 -59.9 -75.8  270  45 23   1.2   0.7 | -60.2 -76.4  275  38 20   0.9   0.5
 45000 -58.1 -72.6  280  46 23   1.0   0.5 | -58.8 -73.8  270  42 22   0.9   0.5
 40000 -60.7 -77.3  275  85 44  -1.8  -1.0 | -59.4 -74.9  270  84 43  -0.5  -0.3
 38000 -59.6 -75.3  270  93 48   6.4   3.5 | -58.4 -73.1  270  94 48   5.0   2.7
 36000 -55.3 -67.5  265  91 47   6.4   3.5 | -55.1 -67.2  265  91 47   5.0   2.7
 34000 -51.3 -60.3  260  88 45   7.9   4.4 | -51.8 -61.2  265  89 46   7.9   4.4
 32000 -46.5 -51.7  265  81 42   7.9   4.3 | -47.1 -52.8  270  89 46   7.8   4.3
 30000 -41.7 -43.1  270  74 38   8.8   4.8 | -42.5 -44.5  275  88 45   7.3   4.0
 29000 -39.0 -38.2  265  71 36   8.8   4.8 | -40.3 -40.5  275  86 44   7.4   4.0
 28000 -36.4 -33.5  265  67 35   8.8   4.8 | -38.1 -36.6  275  83 43   7.4   4.0
 27000 -33.8 -28.8  265  64 33   8.2   4.5 | -35.9 -32.6  275  80 41   7.4   4.1
 26000 -31.9 -25.4  265  60 31   6.1   3.3 | -33.5 -28.3  275  73 38   7.9   4.4
 25000 -30.1 -22.2  265  57 29   6.1   3.3 | -31.2 -24.2  275  65 34   7.9   4.4
 24000 -28.2 -18.8  265  53 27   5.9   3.2 | -28.8 -19.8  270  58 30   8.0   4.4
 23000 -26.1 -15.0  265  52 27   7.9   4.3 | -26.6 -15.9  265  54 28   6.9   3.8
 22000 -23.7 -10.7  265  52 27   7.9   4.3 | -24.6 -12.3  260  53 27   7.0   3.8
 21000 -21.4  -6.5  265  52 27   7.7   4.2 | -22.6  -8.7  255  53 27   7.1   3.9
 20000 -18.8  -1.8  265  50 26   6.9   3.8 | -19.7  -3.5  255  51 26   7.9   4.3
 19500 -17.8  -0.0  265  49 25   6.9   3.8 | -18.5  -1.3  255  50 26   7.9   4.3
 19000 -16.8   1.8  265  48 25   6.9   3.8 | -17.4   0.7  255  49 25   8.0   4.4
 18500 -15.8   3.6  265  47 24   6.4   3.5 | -16.2   2.8  255  48 25   8.1   4.4
 18000 -14.9   5.2  265  47 24   6.0   3.3 | -15.0   5.0  255  46 24   8.3   4.5
 17500 -14.0   6.8  265  46 24   5.9   3.3 | -13.8   7.2  255  43 22   8.5   4.6
 17000 -13.1   8.4  265  46 24   6.8   3.7 | -12.7   9.1  255  42 22   6.8   3.7
 16500 -12.1  10.2  260  45 23   6.7   3.7 | -11.7  10.9  255  43 22   6.9   3.8
 16000 -11.1  12.0  260  44 23   6.8   3.7 | -10.7  12.7  250  43 22   7.0   3.8
 15500 -10.1  13.8  255  43 22   6.8   3.8 |  -9.6  14.7  250  41 21   7.0   3.8
 15000  -9.1  15.6  255  41 21   6.8   3.8 |  -8.6  16.5  245  39 20   7.1   3.9
 14500  -8.2  17.2  250  39 20   6.8   3.7 |  -7.5  18.5  245  38 20   7.3   4.0
 14000  -7.2  19.0  245  37 19   6.8   3.7 |  -6.5  20.3  245  37 19   7.3   4.0
 13500  -6.2  20.8  240  35 18   6.5   3.6 |  -5.3  22.5  245  36 19   8.3   4.5
 13000  -5.2  22.6  235  33 17   6.4   3.5 |  -4.1  24.6  245  35 18   8.1   4.5
 12500  -4.1  24.6  230  31 16   8.6   4.7 |  -2.8  27.0  245  33 17   8.9   4.9
 12000  -2.9  26.8  230  28 15   8.2   4.5 |  -1.5  29.3  245  33 17   8.8   4.9
 11500  -1.5  29.3  230  27 14  10.0   5.5 |  -0.2  31.6  250  32 16   8.9   4.9
 11000  -0.1  31.8  225  26 13   9.8   5.4 |   1.1  34.0  250  31 16   8.9   4.9
 10500   1.4  34.5  225  25 13   9.3   5.1 |   2.5  36.5  250  31 16   8.6   4.7
 10250   2.1  35.8  225  25 13   9.8   5.4 |   3.1  37.6  250  30 16   9.1   5.0
 10000   2.8  37.0  225  25 13  10.5   5.8 |   3.8  38.8  255  30 16   9.6   5.3
  9750   3.6  38.5  225  25 13  10.3   5.7 |   4.5  40.1  255  30 15  10.0   5.5
  9500   4.4  39.9  225  24 12  10.1   5.5 |   5.3  41.5  255  30 15  10.6   5.8
  9250   5.2  41.4  225  24 12  10.2   5.6 |   6.1  43.0  255  29 15  10.7   5.8
  9000   5.9  42.6  225  24 12   9.3   5.1 |   6.8  44.2  260  29 15   7.1   3.9
  8750   6.6  43.9  225  23 12   9.7   5.3 |   7.3  45.1  260  29 15   7.9   4.3
  8500   7.4  45.3  225  23 12  10.4   5.7 |   8.1  46.6  260  28 15  11.0   6.1
  8250   8.1  46.6  225  23 12  10.8   5.9 |   8.8  47.8  260  28 14  10.9   6.0
  8000   8.9  48.0  225  22 11   8.6   4.7 |   9.6  49.3  260  28 14   8.2   4.5
  7750   9.5  49.1  225  22 11   8.3   4.6 |  10.1  50.2  260  27 14   7.8   4.3
  7500  10.2  50.4  225  22 11  10.4   5.7 |  10.9  51.6  265  27 14  10.5   5.8
  7250  11.0  51.8  225  21 11   9.7   5.3 |  11.6  52.9  265  26 14   9.8   5.4
  7000  11.7  53.1  225  21 11  10.3   5.6 |  12.4  54.3  265  26 13   9.8   5.4
  6750  12.5  54.5  225  20 10  10.1   5.6 |  13.1  55.6  265  25 13   9.4   5.2
  6500  13.2  55.8  225  19 10   9.6   5.3 |  13.8  56.8  265  24 13   9.4   5.2
  6250  13.9  57.0  225  18  9  10.0   5.5 |  14.5  58.1  265  24 12   9.4   5.1
  6000  14.7  58.5  225  18  9  10.3   5.6 |  15.2  59.4  265  23 12   9.9   5.4
  5750  15.5  59.9  225  17  9  13.4   7.3 |  16.0  60.8  265  21 11  12.3   6.8
  5500  16.7  62.1  225  16  8  18.5  10.2 |  17.0  62.6  265  19 10  15.1   8.3
  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
________________________________________________________________________________

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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