Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 251245
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0645 MDT Thursday, May 25, 2017

This forecast is for Thursday, May 25, 2017:

If the trigger temperature of 75.9 F/24.4 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1085 ft/min (5.5 m/s)
   Maximum height of thermals.................. 18060 ft MSL (13221 ft AGL)

Forecast maximum temperature................... 81.0 F/27.7 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ 1200 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8177 ft MSL (3338 ft AGL)
Thermal soaring outlook for Friday 05/26....... Good

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

Remarks...

Sunrise/Sunset.................... 05:53:34 / 20:28:31 MDT
Total possible sunshine........... 14 hr 34 min 58 sec (874 min 58 sec)
Altitude of sun at 13:11:14 MDT... 71.95 degrees

Upper air data from rawinsonde observation taken on 05/25/2017 at 0600 MDT

Freezing level.................. 13469 ft MSL (8630 ft AGL)
Convective condensation level... 16157 ft MSL (11318 ft AGL)
Lifted condensation level....... 16637 ft MSL (11798 ft AGL)
Lifted index.................... -2.4
K index......................... +19.1

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -61.5 -78.7   245   45   23 -17.0  -9.3   95.5 203.9    39.2      M    M
 45000  -56.6 -69.9   235   43   22   5.8   3.2   78.9 174.0    31.8      M    M
 40000  -53.9 -65.0   245   67   35  -5.9  -3.3   60.3 140.5    21.7      M    M
 38000  -54.5 -66.1   245   77   40   1.6   0.9   50.6 123.1    15.8      M    M
 36000  -51.4 -60.5   245   70   36   4.8   2.6   45.3 113.6    12.6      M    M
 34000  -48.4 -55.1   245   66   34   6.8   3.7   41.4 106.6    10.2      M    M
 32000  -45.3 -49.5   240   58   30   6.3   3.5   37.7  99.8     7.7      M    M
 30000  -42.2 -44.0   240   47   24   9.4   5.1   34.0  93.2     5.1      M    M
 29000  -39.4 -38.9   240   42   22   9.4   5.1   33.8  92.9     5.0      M    M
 28000  -36.6 -33.9   240   42   22   9.0   5.0   33.6  92.5     4.9      M    M
 27000  -34.0 -29.2   240   43   22   8.3   4.6   33.2  91.7     4.6      M    M
 26000  -31.5 -24.7   240   43   22   8.6   4.7   32.6  90.7     4.2      M    M
 25000  -28.9 -20.0   240   44   23   8.8   4.8   32.3  90.1     4.0      M    M
 24000  -26.3 -15.3   240   43   22   8.7   4.8   31.9  89.5     3.7      M    M
 23000  -24.0 -11.2   235   42   22   7.5   4.1   31.2  88.1     3.1      M    M
 22000  -21.7  -7.1   235   41   21   7.4   4.1   30.4  86.8     2.5      M    M
 21000  -19.4  -2.9   230   40   21   8.4   4.6   29.7  85.5     1.9      M    M
 20000  -16.9   1.6   240   40   21   8.4   4.6   29.3  84.7     1.5      M    M
 19500  -15.0   5.0   240   40   21   8.5   4.7   28.9  84.0     1.2      M    M
 19000  -13.9   7.0   245   40   21   7.6   4.2   28.6  83.5     0.9      M    M
 18500  -12.9   8.8   245   41   21   5.7   3.1   28.0  82.5     0.4      M    M
 18000  -12.0  10.4   250   42   22   5.7   3.1   27.4  81.3    -0.2   1272  6.5
 17500  -11.1  12.0   255   44   22   8.0   4.4   26.8  80.3    -0.7   1230  6.2
 17000   -9.8  14.4   255   45   23   9.3   5.1   26.7  80.1    -0.9   1175  6.0
 16500   -8.4  16.9   255   44   23   9.3   5.1   26.6  79.9    -0.9   1119  5.7
 16000   -7.0  19.4   255   44   23   9.3   5.1   26.5  79.8    -1.0   1062  5.4
 15500   -5.6  21.9   255   43   22   9.3   5.1   26.4  79.6    -1.1   1006  5.1
 15000   -4.2  24.4   250   43   22   9.3   5.1   26.3  79.4    -1.2    949  4.8
 14500   -2.8  27.0   250   42   22   9.3   5.1   26.3  79.3    -1.3    893  4.5
 14000   -1.4  29.5   250   42   22   9.5   5.2   26.2  79.2    -1.3    836  4.2
 13500    0.0  32.0   250   41   21   9.5   5.2   26.2  79.1    -1.4    778  4.0
 13000    1.4  34.5   250   41   21   9.5   5.2   26.1  79.0    -1.4    721  3.7
 12500    2.8  37.0   250   40   21   9.5   5.2   26.1  79.0    -1.5    664  3.4
 12000    4.2  39.6   250   40   21   9.5   5.2   26.1  78.9    -1.5    607  3.1
 11500    5.7  42.3   250   38   19   9.5   5.2   26.0  78.8    -1.6    550  2.8
 11000    7.1  44.8   250   36   18   9.4   5.2   25.9  78.7    -1.7    493  2.5
 10500    8.5  47.3   245   34   17   8.5   4.7   25.9  78.6    -1.7    435  2.2
 10250    9.0  48.2   245   33   17   7.0   3.8   25.7  78.2    -1.9    412  2.1
 10000    9.5  49.1   245   32   16   7.4   4.1   25.5  77.9    -2.2    389  2.0
  9750   10.1  50.2   245   30   16   8.4   4.6   25.3  77.6    -2.3    365  1.9
  9500   10.7  51.3   250   29   15   8.8   4.8   25.3  77.5    -2.4    339  1.7
  9250   11.4  52.5   255   28   14   8.7   4.8   25.2  77.3    -2.5    312  1.6
  9000   12.0  53.6   260   27   14   8.7   4.8   25.1  77.2    -2.6    286  1.5
  8750   12.6  54.7   260   26   13   8.8   4.8   25.0  77.0    -2.7    259  1.3
  8500   13.3  55.9   265   25   13   8.7   4.7   24.9  76.9    -2.9    233  1.2
  8250   13.9  57.0   265   24   12   9.1   5.0   24.9  76.7    -3.0    206  1.0
  8000   14.5  58.1   270   23   12   7.6   4.1   24.8  76.6    -3.1    180  0.9
  7750   15.0  59.0   265   21   11   5.8   3.2   24.5  76.1    -3.3    159  0.8
  7500   15.4  59.7   265   19   10   6.1   3.4   24.2  75.6    -3.6    138  0.7
  7250   15.9  60.6   260   16    8   6.0   3.3   23.9  75.1    -3.9    118  0.6
  7000   16.3  61.3   250   14    7   6.3   3.5   23.7  74.6    -4.2     97  0.5
  6750   16.8  62.2   255   12    6   8.1   4.4   23.5  74.2    -4.5     74  0.4
  6500   17.5  63.5   260    9    5   9.2   5.0   23.4  74.1    -4.5     47  0.2
  6250   18.2  64.8   265    7    3   8.9   4.9   23.3  74.0    -4.6     19  0.1
  6000   18.8  65.8   285    4    2   9.0   4.9   23.3  73.9    -4.7      M    M
  5750   19.5  67.1   300    3    2   8.9   4.9   23.2  73.8    -4.7      M    M
  5500   20.2  68.4   310    3    1   9.0   5.0   23.2  73.7    -4.8      M    M
  5250   20.9  69.6   330    2    1   8.5   4.7   23.1  73.6    -4.9      M    M
  5000   21.1  70.0   005    2    1  -5.6  -3.1   22.6  72.7    -5.4      M    M

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

           05/25/2017 at 0900 MDT          |       05/25/2017 at 1200 MDT
                                           |
K index... +25.0  LI... -0.6               | K index... +26.5  LI... -1.5
CAPE... +237.3  CIN... -46.9               | CAPE... +224.8  CIN... -27.3
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -59.8 -75.6  260  32 16   2.8   1.5 | -59.3 -74.7  255  38 20   2.1   1.1
 45000 -55.8 -68.4  255  46 24   1.1   0.6 | -56.3 -69.3  255  49 25   1.1   0.6
 40000 -53.9 -65.0  255  57 29   1.2   0.7 | -54.5 -66.1  255  53 27   1.2   0.7
 38000 -52.8 -63.0  255  58 30   2.4   1.3 | -53.3 -63.9  260  52 27   2.7   1.5
 36000 -51.2 -60.2  255  58 30   2.4   1.3 | -51.5 -60.7  260  48 25   2.7   1.5
 34000 -49.2 -56.6  255  55 28   5.2   2.8 | -49.3 -56.7  265  46 24   5.6   3.1
 32000 -46.1 -51.0  255  45 23   5.2   2.9 | -45.9 -50.6  265  45 23   5.6   3.1
 30000 -42.4 -44.3  255  37 19   8.3   4.5 | -41.9 -43.4  265  44 22   8.8   4.8
 29000 -39.9 -39.8  255  35 18   8.3   4.6 | -39.3 -38.7  265  42 21   8.8   4.8
 28000 -37.4 -35.3  255  34 17   8.3   4.6 | -36.6 -33.9  265  40 21   8.8   4.8
 27000 -35.0 -31.0  255  33 17   8.2   4.5 | -34.0 -29.2  265  38 20   8.0   4.4
 26000 -32.5 -26.5  255  37 19   8.1   4.5 | -31.7 -25.1  260  40 20   7.7   4.2
 25000 -30.1 -22.2  250  42 22   8.1   4.5 | -29.4 -20.9  260  41 21   7.7   4.3
 24000 -27.7 -17.9  250  46 24   8.2   4.5 | -27.1 -16.8  260  42 22   7.7   4.2
 23000 -25.2 -13.4  250  49 25   8.3   4.6 | -24.9 -12.8  255  44 22   7.5   4.1
 22000 -22.7  -8.9  250  51 26   8.4   4.6 | -22.7  -8.9  255  45 23   7.5   4.1
 21000 -20.2  -4.4  250  53 27   8.5   4.7 | -19.8  -3.6  255  46 24   8.2   4.5
 20000 -17.0   1.4  255  51 26   8.6   4.7 | -17.4   0.7  250  45 23   8.1   4.5
 19500 -15.7   3.7  255  50 26   8.6   4.7 | -16.2   2.8  250  44 23   8.1   4.5
 19000 -14.5   5.9  255  49 25   8.6   4.7 | -15.0   5.0  245  44 23   8.1   4.5
 18500 -13.2   8.2  255  48 25   8.6   4.7 | -13.8   7.2  245  42 22   8.4   4.6
 18000 -11.9  10.6  255  47 24   8.6   4.7 | -12.6   9.3  245  40 21   8.5   4.6
 17500 -10.7  12.7  255  45 23   8.6   4.7 | -11.4  11.5  245  37 19   8.4   4.6
 17000  -9.4  15.1  255  44 23   8.5   4.7 | -10.2  13.6  245  36 18   8.2   4.5
 16500  -8.2  17.2  255  42 22   8.6   4.7 |  -9.0  15.8  240  34 18   8.2   4.5
 16000  -7.0  19.4  255  41 21   8.3   4.6 |  -7.8  18.0  240  33 17   8.5   4.7
 15500  -5.8  21.6  255  40 21   8.4   4.6 |  -6.5  20.3  240  32 16   8.5   4.6
 15000  -4.5  23.9  255  39 20   8.6   4.7 |  -5.3  22.5  240  30 16   8.5   4.6
 14500  -3.3  26.1  255  37 19   8.6   4.7 |  -4.0  24.8  240  29 15   8.5   4.7
 14000  -2.0  28.4  255  36 18   8.6   4.7 |  -2.8  27.0  240  28 14   8.9   4.9
 13500  -0.8  30.6  255  34 17   8.5   4.7 |  -1.4  29.5  240  27 14   9.3   5.1
 13000   0.5  32.9  255  32 16   8.4   4.6 |  -0.0  32.0  240  25 13   9.0   5.0
 12500   1.7  35.1  255  30 15   8.3   4.6 |   1.2  34.2  240  23 12   8.1   4.5
 12000   3.0  37.4  255  28 15   8.3   4.6 |   2.4  36.3  240  21 11   8.2   4.5
 11500   4.2  39.6  260  27 14   8.3   4.6 |   3.7  38.7  240  19 10   8.7   4.8
 11000   5.4  41.7  260  26 13   8.3   4.6 |   5.0  41.0  235  17  9   8.7   4.8
 10500   6.6  43.9  265  24 13   7.6   4.2 |   6.3  43.3  235  15  8   8.5   4.7
 10250   7.2  45.0  265  24 12   8.4   4.6 |   6.9  44.4  235  14  7   8.8   4.8
 10000   7.8  46.0  265  23 12   9.0   5.0 |   7.6  45.7  235  13  7   9.2   5.0
  9750   8.5  47.3  265  23 12   8.2   4.5 |   8.3  46.9  235  13  6   9.9   5.4
  9500   9.0  48.2  265  22 11   7.9   4.3 |   9.0  48.2  235  12  6  10.5   5.8
  9250   9.6  49.3  265  21 11   7.8   4.3 |   9.8  49.6  235  12  6   9.8   5.4
  9000  10.2  50.4  265  20 10   6.3   3.5 |  10.5  50.9  235  11  6   8.6   4.7
  8750  10.6  51.1  265  19 10   6.2   3.4 |  11.2  52.2  235  11  6  10.0   5.5
  8500  11.1  52.0  265  17  9   6.8   3.8 |  12.0  53.6  235  11  6  11.0   6.0
  8250  11.7  53.1  260  16  8   7.0   3.9 |  12.8  55.0  235  11  6  11.3   6.2
  8000  12.2  54.0  260  14  7   5.7   3.1 |  13.6  56.5  235  11  6   9.2   5.1
  7750  12.6  54.7  260  13  6   4.9   2.7 |  14.2  57.6  235  11  6   8.7   4.8
  7500  13.0  55.4  255  11  6   5.7   3.1 |  15.0  59.0  235  11  6  10.5   5.7
  7250  13.4  56.1  250   9  5   5.5   3.0 |  15.7  60.3  235  11  6  10.1   5.6
  7000  13.9  57.0  245   7  4   5.4   2.9 |  16.5  61.7  235  11  5   9.7   5.3
  6750  14.3  57.7  235   6  3   5.7   3.1 |  17.2  63.0  235  10  5   9.6   5.3
  6500  14.7  58.5  220   5  3   5.8   3.2 |  17.9  64.2  235  10  5  10.0   5.5
  6250  15.1  59.2  210   5  2   6.7   3.7 |  18.7  65.7  240  10  5  10.3   5.6
  6000  15.7  60.3  200   5  2   8.9   4.9 |  19.5  67.1  240  10  5  10.7   5.9
  5750  16.5  61.7  200   4  2  14.3   7.8 |  20.5  68.9  240  10  5  18.8  10.3
  5500  17.8  64.0  200   4  2  21.6  11.8 |  22.4  72.3  240  10  5  32.7  17.9
  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

           05/25/2017 at 1500 MDT          |       05/25/2017 at 1800 MDT
                                           |
K index... +23.9  LI... -1.3               | K index... +27.0  LI... -2.0
CAPE... +176.2  CIN... -36.7               | CAPE... +261.8  CIN... -82.1
                                           |
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 -58.9 -74.0  255  39 20   1.5   0.8 | -58.4 -73.1  255  38 20   1.6   0.9
 45000 -56.6 -69.9  255  48 25   1.0   0.5 | -56.2 -69.2  260  50 26  -0.0  -0.0
 40000 -55.1 -67.2  260  50 26   1.0   0.6 | -56.1 -69.0  260  51 26   0.1   0.0
 38000 -53.7 -64.7  260  46 24   2.7   1.5 | -54.6 -66.3  260  49 25   3.5   1.9
 36000 -52.0 -61.6  260  40 21   2.7   1.5 | -52.5 -62.5  260  46 24   3.5   1.9
 34000 -49.6 -57.3  260  37 19   6.6   3.6 | -49.8 -57.6  255  44 23   7.0   3.9
 32000 -45.6 -50.1  260  41 21   6.7   3.7 | -45.5 -49.9  255  45 23   7.1   3.9
 30000 -41.2 -42.2  255  43 22   8.6   4.7 | -41.1 -42.0  250  45 23   8.1   4.4
 29000 -38.7 -37.7  250  44 23   8.6   4.7 | -38.7 -37.7  250  46 23   8.1   4.5
 28000 -36.1 -33.0  250  44 23   8.6   4.7 | -36.3 -33.3  250  46 24   8.1   4.5
 27000 -33.5 -28.3  250  45 23   8.2   4.5 | -33.3 -27.9  250  46 24   7.9   4.3
 26000 -31.1 -24.0  250  45 23   8.1   4.4 | -30.9 -23.6  250  47 24   7.9   4.3
 25000 -28.7 -19.7  250  45 23   8.1   4.4 | -28.6 -19.5  255  47 24   7.9   4.3
 24000 -26.3 -15.3  250  45 23   7.8   4.3 | -26.2 -15.2  255  48 25   7.4   4.1
 23000 -24.1 -11.4  250  44 22   7.3   4.0 | -24.1 -11.4  260  48 25   7.3   4.0
 22000 -21.9  -7.4  250  42 22   7.3   4.0 | -21.9  -7.4  260  48 25   7.3   4.0
 21000 -19.2  -2.6  255  41 21   7.7   4.3 | -19.7  -3.5  265  48 25   7.7   4.2
 20000 -16.9   1.6  255  40 21   7.7   4.2 | -17.4   0.7  265  48 25   7.7   4.2
 19500 -15.8   3.6  255  40 21   7.7   4.2 | -16.3   2.7  265  47 24   7.7   4.2
 19000 -14.6   5.7  255  40 20   7.7   4.2 | -15.2   4.6  265  47 24   7.7   4.2
 18500 -13.4   7.9  255  40 20   8.6   4.7 | -14.0   6.8  265  46 24   7.7   4.2
 18000 -12.2  10.0  255  40 21   8.6   4.7 | -12.9   8.8  265  45 23   7.7   4.2
 17500 -10.9  12.4  255  40 21   8.4   4.6 | -11.8  10.8  260  43 22   7.9   4.3
 17000  -9.7  14.5  255  40 21   8.3   4.5 | -10.5  13.1  260  40 21   8.7   4.8
 16500  -8.5  16.7  255  40 20   8.3   4.5 |  -9.3  15.3  260  37 19   8.7   4.8
 16000  -7.2  19.0  255  39 20   8.4   4.6 |  -8.0  17.6  260  35 18   8.8   4.8
 15500  -6.0  21.2  255  39 20   8.4   4.6 |  -6.8  19.8  260  33 17   8.8   4.9
 15000  -4.8  23.4  255  38 20   8.2   4.5 |  -5.5  22.1  255  31 16   8.9   4.9
 14500  -3.6  25.5  255  37 19   8.2   4.5 |  -4.2  24.4  255  30 15   9.0   4.9
 14000  -2.4  27.7  255  36 18   8.4   4.6 |  -2.9  26.8  255  29 15   8.9   4.9
 13500  -1.1  30.0  255  34 18   8.7   4.8 |  -0.9  30.4  250  27 14   8.7   4.8
 13000   0.2  32.4  255  33 17   8.7   4.8 |   0.3  32.5  250  26 13   8.6   4.7
 12500   1.4  34.5  255  31 16   8.6   4.7 |   1.6  34.9  250  25 13   8.6   4.7
 12000   2.7  36.9  255  29 15   8.5   4.7 |   2.9  37.2  250  24 12   8.7   4.7
 11500   3.9  39.0  255  26 14   8.0   4.4 |   4.1  39.4  250  22 12   8.7   4.8
 11000   5.1  41.2  250  23 12   8.1   4.5 |   5.4  41.7  250  21 11   8.5   4.7
 10500   6.3  43.3  250  19 10   8.5   4.7 |   6.7  44.1  250  20 10   8.3   4.6
 10250   7.0  44.6  255  17  9   8.5   4.7 |   7.3  45.1  250  19 10   9.0   4.9
 10000   7.6  45.7  250  16  8   8.8   4.8 |   8.0  46.4  250  19 10   8.9   4.9
  9750   8.3  46.9  250  15  8   9.7   5.3 |   8.6  47.5  255  18  9   8.4   4.6
  9500   9.0  48.2  250  15  8  10.5   5.8 |   9.2  48.6  255  17  9   8.6   4.7
  9250   9.8  49.6  250  14  7   9.6   5.2 |   9.9  49.8  255  17  9   8.3   4.6
  9000  10.4  50.7  250  14  7   8.0   4.4 |  10.4  50.7  255  16  8   7.8   4.3
  8750  11.1  52.0  250  14  7   9.6   5.3 |  11.0  51.8  260  15  8   7.9   4.3
  8500  11.9  53.4  250  14  7  10.9   6.0 |  11.6  52.9  260  15  8   7.5   4.1
  8250  12.7  54.9  250  13  7  11.0   6.1 |  12.2  54.0  265  14  7   9.0   4.9
  8000  13.5  56.3  250  13  7   9.0   5.0 |  12.8  55.0  270  13  7   7.9   4.4
  7750  14.0  57.2  250  13  7   8.6   4.7 |  13.3  55.9  280  12  6   5.6   3.1
  7500  14.8  58.6  250  13  7  10.4   5.7 |  13.7  56.7  290  11  6   6.2   3.4
  7250  15.6  60.1  250  13  7  10.0   5.5 |  14.2  57.6  295  11  6   6.1   3.4
  7000  16.3  61.3  250  12  6  10.0   5.5 |  14.6  58.3  310  10  5   7.3   4.0
  6750  17.1  62.8  250  12  6  10.1   5.6 |  15.2  59.4  315  10  5   8.4   4.6
  6500  17.8  64.0  250  12  6  10.2   5.6 |  15.8  60.4  320  10  5   8.0   4.4
  6250  18.6  65.5  250  12  6  10.6   5.8 |  16.4  61.5  325  11  5   9.7   5.3
  6000  19.4  66.9  250  11  6  10.8   5.9 |  17.2  63.0  325  10  5  11.5   6.3
  5750  20.4  68.7  245  11  6  18.8  10.3 |  18.1  64.6  325  10  5  10.6   5.8
  5500  22.3  72.1  245  11  6  32.9  18.0 |  18.9  66.0  325  10  5  11.1   6.1
  5250     M     M    M   M  M     M     M |  19.7  67.5  325   9  5  12.9   7.1
  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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