Soaring Guidance
Issued by NWS Grand Junction, CO

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375
UXUS97 KGJT 091221
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0521 MST Friday, December 9, 2016

This forecast is for Friday, December 9, 2016:

If the trigger temperature of 45.4 F/7.5 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 7413 ft MSL (2574 ft AGL)

Forecast maximum temperature................... 42.0 F/6.0 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 6357 ft MSL (1518 ft AGL)
Thermal soaring outlook for Saturday 12/10..... Poor

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

Remarks...

Sunrise/Sunset.................... 07:22:02 / 16:51:35 MST
Total possible sunshine........... 9 hr 29 min 33 sec (569 min 33 sec)
Altitude of sun at 12:06:53 MST... 28.04 degrees

Upper air data from rawinsonde observation taken on 12/09/2016 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 18075 ft MSL (13236 ft AGL)
Lifted condensation level....... 11673 ft MSL (6834 ft AGL)
Lifted index.................... +14.3
K index......................... +13.1

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  -59.9 -75.8   280   57   29  -6.0  -3.3  103.6 218.5    55.5      M    M
 45000  -57.0 -70.6   285   70   36   4.5   2.5   83.5 182.3    47.2      M    M
 40000  -60.8 -77.4   295   74   38  -3.0  -1.6   54.2 129.6    31.6      M    M
 38000  -60.4 -76.7   300   78   40   1.6   0.9   45.9 114.6    26.9      M    M
 36000  -60.1 -76.2   305   83   43  -6.1  -3.3   37.7  99.9    22.0      M    M
 34000  -57.1 -70.8   300   77   40   7.2   4.0   32.6  90.6    19.1      M    M
 32000  -52.1 -61.8   295   70   36   9.6   5.3   31.3  88.3    18.7      M    M
 30000  -46.5 -51.7   290   62   32   8.3   4.6   31.0  87.8    18.9      M    M
 29000  -44.0 -47.2   290   60   31   9.0   4.9   30.4  86.8    18.8      M    M
 28000  -41.3 -42.3   295   61   32   8.8   4.8   30.1  86.2    18.8      M    M
 27000  -38.7 -37.7   295   63   32   8.8   4.8   29.8  85.6    18.7      M    M
 26000  -36.1 -33.0   300   64   33   7.9   4.3   29.3  84.8    18.6      M    M
 25000  -33.7 -28.7   300   66   34   7.9   4.3   28.6  83.6    18.3      M    M
 24000  -31.3 -24.3   300   66   34   8.8   4.8   28.0  82.4    18.0      M    M
 23000  -28.5 -19.3   300   65   33   9.6   5.3   27.9  82.2    18.1      M    M
 22000  -26.1 -15.0   295   64   33  -6.1  -3.3   27.3  81.1    17.8      M    M
 21000  -24.8 -12.6   295   63   32   9.3   5.1   25.4  77.8    16.4      M    M
 20000  -22.0  -7.6   290   62   32   8.8   4.8   25.3  77.5    16.4      M    M
 19500  -20.7  -5.3   290   61   31   4.8   2.6   25.2  77.3    16.4      M    M
 19000  -20.4  -4.7   285   60   31   6.6   3.6   23.8  74.9    15.4      M    M
 18500  -18.5  -1.3   285   59   31   8.3   4.6   23.5  74.3    15.2      M    M
 18000  -17.3   0.9   285   58   30   6.3   3.5   23.2  73.7    15.0      M    M
 17500  -17.0   1.4   285   52   27   0.3   0.2   21.8  71.3    13.9      M    M
 17000  -16.9   1.6   280   46   23  -0.0  -0.0   20.3  68.5    12.6      M    M
 16500  -16.4   2.5   280   39   20   7.3   4.0   19.2  66.6    11.8      M    M
 16000  -15.4   4.3   275   34   17   6.6   3.6   18.7  65.7    11.3      M    M
 15500  -14.5   5.9   270   31   16   6.6   3.6   18.2  64.7    10.9      M    M
 15000  -13.5   7.7   270   29   15   6.6   3.6   17.6  63.7    10.4      M    M
 14500  -12.5   9.5   280   28   15   7.5   4.1   17.1  62.8    10.0      M    M
 14000  -11.4  11.5   285   28   14   7.8   4.3   16.8  62.3     9.8      M    M
 13500  -10.2  13.6   280   28   15   7.9   4.3   16.5  61.6     9.5      M    M
 13000   -9.0  15.8   280   28   15   7.9   4.4   16.2  61.1     9.2      M    M
 12500   -7.9  17.8   275   29   15   8.7   4.8   15.9  60.6     9.0      M    M
 12000   -7.2  19.0   275   29   15  -0.3  -0.2   15.1  59.1     8.3      M    M
 11500   -6.5  20.3   270   29   15   9.7   5.3   14.3  57.7     7.6      M    M
 11000   -5.1  22.8   265   29   15   9.8   5.4   14.2  57.5     7.5      M    M
 10500   -4.2  24.4   265   29   15   5.5   3.0   13.6  56.4     7.0      M    M
 10250   -3.9  25.0   260   29   15  -5.7  -3.1   13.1  55.6     6.6      M    M
 10000   -4.9  23.2   265   31   16 -13.9  -7.6   11.2  52.2     4.9      M    M
  9750   -5.4  22.3   260   28   15  -0.5  -0.3    9.9  49.8     3.7      M    M
  9500   -5.2  22.6   255   26   13   3.1   1.7    9.3  48.8     3.2      M    M
  9250   -5.0  23.0   245   24   12   2.0   1.1    8.7  47.7     2.6      M    M
  9000   -4.8  23.4   235   22   11   3.0   1.6    8.2  46.7     2.1      M    M
  8750   -4.5  23.9   235   18    9   6.9   3.8    7.8  46.0     1.7      M    M
  8500   -3.8  25.2   230   14    7   9.0   4.9    7.7  45.8     1.6      M    M
  8250   -3.2  26.2   230   10    5   8.7   4.8    7.6  45.6     1.6      M    M
  8000   -2.5  27.5   220    7    3   7.6   4.2    7.5  45.5     1.5      M    M
  7750   -1.9  28.6   220    5    3  12.3   6.8    7.4  45.3     1.4      M    M
  7500   -1.4  29.5   215    5    2  -9.6  -5.3    7.2  45.0     1.2      M    M
  7250   -2.8  27.0   210    4    2 -12.0  -6.6    4.9  40.8    -1.0    168  0.9
  7000   -2.6  27.3   205    3    2   7.6   4.2    4.4  39.9    -1.5    152  0.8
  6750   -2.2  28.0   200    3    1   3.8   2.1    4.0  39.2    -1.9    134  0.7
  6500   -1.9  28.6   195    2    1   2.5   1.3    3.6  38.4    -2.2    116  0.6
  6250   -2.0  28.4   185    2    1  -8.2  -4.5    2.6  36.7    -3.2    114  0.6
  6000   -2.7  27.1   175    2    1  -1.5  -0.8    1.3  34.3    -4.5    126  0.6
  5750   -2.4  27.7   165    1    1   1.6   0.9    0.8  33.5    -5.0    109  0.6
  5500   -2.7  27.1   145    1    0  -8.5  -4.6   -0.3  31.4    -6.1    113  0.6
  5250   -3.3  26.1   075    1    0  -6.5  -3.6   -1.6  29.1    -7.4    123  0.6
  5000   -3.7  25.3   035    1    0  -3.9  -2.1   -2.7  27.1    -8.6    128  0.6

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

           12/09/2016 at 0800 MST          |       12/09/2016 at 1100 MST
                                           |
K index... +18.6  LI... +3.5               | K index... +14.0  LI... +4.5
CAPE... +7.3  CIN... -8.6                  | CAPE... 0.0  CIN... -0.4
                                           |
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 -63.0 -81.4  285  44 23   2.2   1.2 | -62.9 -81.2  290  54 28   0.9   0.5
 45000 -59.6 -75.3  285  52 27   2.6   1.4 | -61.5 -78.7  285  60 31   1.2   0.6
 40000 -61.6 -78.9  315  82 42  -1.5  -0.8 | -63.2 -81.8  305  80 41  -1.3  -0.7
 38000 -60.8 -77.4  315  89 46   4.6   2.5 | -62.0 -79.6  310  82 42   5.3   2.9
 36000 -58.0 -72.4  310  89 46   4.6   2.5 | -58.8 -73.8  300  76 39   5.3   2.9
 34000 -55.0 -67.0  310  88 45   8.1   4.5 | -55.2 -67.4  300  72 37   8.2   4.5
 32000 -50.2 -58.4  310  80 41   7.9   4.3 | -50.3 -58.5  305  68 35   8.2   4.5
 30000 -45.5 -49.9  310  72 37   8.0   4.4 | -45.3 -49.5  305  66 34   8.7   4.8
 29000 -43.1 -45.6  310  71 36   8.0   4.4 | -42.7 -44.9  305  66 34   8.8   4.8
 28000 -40.6 -41.1  310  69 36   8.0   4.4 | -40.0 -40.0  305  66 34   8.8   4.8
 27000 -38.2 -36.8  310  67 35   8.0   4.4 | -37.4 -35.3  305  66 34   8.7   4.7
 26000 -35.9 -32.6  310  68 35   7.8   4.3 | -34.8 -30.6  305  66 34   8.5   4.7
 25000 -33.5 -28.3  305  68 35   7.9   4.3 | -32.3 -26.1  305  66 34   8.5   4.7
 24000 -31.2 -24.2  305  69 35   7.8   4.3 | -29.7 -21.5  305  65 34   8.2   4.5
 23000 -28.9 -20.0  305  67 35   7.6   4.2 | -27.5 -17.5  305  63 33   7.3   4.0
 22000 -26.0 -14.8  305  64 33   7.7   4.2 | -24.8 -12.6  305  61 31   7.3   4.0
 21000 -23.8 -10.8  305  62 32   6.6   3.6 | -22.7  -8.9  305  58 30   5.6   3.1
 20000 -21.8  -7.2  305  58 30   6.7   3.7 | -21.0  -5.8  305  54 28   5.8   3.2
 19500 -20.8  -5.4  305  56 29   6.8   3.7 | -20.2  -4.4  305  52 27   5.8   3.2
 19000 -19.9  -3.8  305  54 28   6.9   3.8 | -19.3  -2.7  300  50 26   5.7   3.1
 18500 -18.9  -2.0  305  52 27   5.4   3.0 | -18.4  -1.1  300  48 25   6.8   3.8
 18000 -18.1  -0.6  300  50 26   5.3   2.9 | -17.4   0.7  300  47 24   6.8   3.7
 17500 -17.4   0.7  300  47 24   4.4   2.4 | -16.4   2.5  300  45 23   6.6   3.6
 17000 -16.9   1.6  295  43 22   3.0   1.6 | -15.4   4.3  300  44 23   6.4   3.5
 16500 -16.5   2.3  295  38 19   3.0   1.6 | -14.5   5.9  295  43 22   6.2   3.4
 16000 -16.0   3.2  290  33 17   3.9   2.1 | -13.8   7.2  295  42 21   3.5   1.9
 15500 -15.4   4.3  290  27 14   3.5   1.9 | -13.3   8.1  290  40 21   3.8   2.1
 15000 -14.7   5.5  295  24 12   7.5   4.1 | -12.8   9.0  290  38 19   2.9   1.6
 14500 -13.5   7.7  295  24 12   7.6   4.2 | -12.3   9.9  290  34 18   2.8   1.5
 14000 -12.4   9.7  300  24 12   8.2   4.5 | -11.8  10.8  295  31 16   5.2   2.8
 13500 -11.2  11.8  300  26 13   8.4   4.6 | -11.0  12.2  290  29 15   5.6   3.0
 13000 -10.0  14.0  295  28 14   7.2   3.9 | -10.1  13.8  290  26 14   6.3   3.5
 12500  -9.0  15.8  295  28 15   6.7   3.7 |  -9.2  15.4  290  24 13   6.5   3.6
 12000  -8.0  17.6  295  29 15   6.9   3.8 |  -8.2  17.2  290  23 12   7.5   4.1
 11500  -7.0  19.4  295  29 15   7.1   3.9 |  -7.0  19.4  295  22 11   7.8   4.3
 11000  -6.0  21.2  290  29 15   5.5   3.0 |  -5.9  21.4  295  21 11   8.0   4.4
 10500  -5.3  22.5  290  27 14   5.1   2.8 |  -4.7  23.5  295  20 10   8.5   4.6
 10250  -5.0  23.0  290  26 14   3.6   2.0 |  -4.1  24.6  295  19 10   6.5   3.6
 10000  -4.8  23.4  285  25 13   0.7   0.4 |  -3.8  25.2  290  19 10   3.1   1.7
  9750  -4.8  23.4  285  23 12   0.9   0.5 |  -3.6  25.5  290  18  9   2.8   1.5
  9500  -4.6  23.7  280  20 11   1.7   0.9 |  -3.3  26.1  285  17  9   3.4   1.9
  9250  -4.5  23.9  275  18  9   2.1   1.1 |  -3.1  26.4  280  15  8   2.4   1.3
  9000  -4.3  24.3  270  17  9   2.8   1.6 |  -3.0  26.6  270  14  7   1.3   0.7
  8750  -4.0  24.8  265  15  8   3.6   2.0 |  -2.8  27.0  265  13  7   2.0   1.1
  8500  -3.7  25.3  260  14  7   4.5   2.5 |  -2.6  27.3  255  11  6   2.5   1.4
  8250  -3.3  26.1  250  12  6   5.1   2.8 |  -2.4  27.7  240  10  5   2.9   1.6
  8000  -2.8  27.0  245  11  6   5.6   3.1 |  -2.2  28.0  235   9  5   3.0   1.7
  7750  -2.4  27.7  240  10  5   5.8   3.2 |  -1.9  28.6  225   8  4   3.4   1.9
  7500  -2.0  28.4  230   9  4   4.6   2.5 |  -1.6  29.1  210   7  3   4.0   2.2
  7250  -1.7  28.9  220   9  4   3.0   1.6 |  -1.3  29.7  200   7  3   4.1   2.2
  7000  -1.5  29.3  205   9  5   3.0   1.7 |  -1.0  30.2  190   7  4   3.7   2.0
  6750  -1.3  29.7  195  10  5   3.2   1.7 |  -0.7  30.7  185   8  4   5.3   2.9
  6500  -1.1  30.0  190  10  5   3.1   1.7 |  -0.2  31.6  180   8  4   6.4   3.5
  6250  -0.9  30.4  185   9  5   3.0   1.7 |   0.2  32.4  180   7  4   5.7   3.1
  6000  -0.7  30.7  180   9  5   2.5   1.4 |   0.6  33.1  180   6  3   6.0   3.3
  5750  -0.7  30.7  175   9  5  -4.9  -2.7 |   1.1  34.0  175   6  3  10.2   5.6
  5500  -1.5  29.3  170   6  3 -15.2  -8.3 |   2.1  35.8  175   6  3  16.8   9.2
  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

           12/09/2016 at 1400 MST          |       12/09/2016 at 1700 MST
                                           |
K index... +13.1  LI... +4.4               | K index... +12.2  LI... +5.7
CAPE... 0.0  CIN... -0.4                   | 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 -63.5 -82.3  280  58 30   0.9   0.5 | -64.3 -83.7  285  57 29   0.2   0.1
 45000 -62.1 -79.8  280  61 32   1.1   0.6 | -63.9 -83.0  285  63 32   0.2   0.1
 40000 -63.4 -82.1  300  75 38  -0.9  -0.5 | -63.5 -82.3  300  70 36   0.3   0.2
 38000 -61.9 -79.4  300  78 40   5.5   3.0 | -61.5 -78.7  300  71 36   5.7   3.1
 36000 -58.6 -73.5  295  78 40   5.5   3.0 | -58.1 -72.6  300  67 35   5.7   3.1
 34000 -55.0 -67.0  295  76 39   8.0   4.4 | -54.4 -65.9  300  64 33   7.4   4.1
 32000 -50.2 -58.4  295  69 35   8.0   4.4 | -49.9 -57.8  300  61 32   7.5   4.1
 30000 -45.2 -49.4  290  62 32   9.4   5.2 | -45.2 -49.4  295  58 30   9.0   4.9
 29000 -42.3 -44.1  295  60 31   9.5   5.2 | -42.5 -44.5  295  56 29   9.0   5.0
 28000 -39.5 -39.1  295  57 29   9.5   5.2 | -39.8 -39.6  290  55 28   9.0   5.0
 27000 -36.7 -34.1  295  55 28   8.6   4.7 | -37.1 -34.8  290  53 27   8.4   4.6
 26000 -34.3 -29.7  295  53 28   8.0   4.4 | -34.7 -30.5  290  50 26   8.0   4.4
 25000 -31.9 -25.4  295  52 27   8.0   4.4 | -32.3 -26.1  290  47 24   8.0   4.4
 24000 -29.5 -21.1  295  51 26   7.7   4.2 | -29.9 -21.8  295  45 23   8.1   4.5
 23000 -27.4 -17.3  295  49 25   7.0   3.9 | -27.4 -17.3  295  45 23   8.3   4.6
 22000 -24.8 -12.6  295  48 25   7.1   3.9 | -25.0 -13.0  295  45 23   8.3   4.6
 21000 -22.7  -8.9  295  47 24   6.4   3.5 | -22.0  -7.6  290  45 23   7.2   3.9
 20000 -20.8  -5.4  290  45 23   6.4   3.5 | -19.8  -3.6  290  46 23   7.3   4.0
 19500 -19.9  -3.8  290  45 23   6.4   3.5 | -18.7  -1.7  290  46 24   7.3   4.0
 19000 -18.9  -2.0  290  44 23   6.5   3.6 | -17.7   0.1  290  46 24   7.6   4.2
 18500 -18.0  -0.4  290  43 22   5.8   3.2 | -16.8   1.8  290  45 23   4.1   2.2
 18000 -17.1   1.2  290  42 22   5.9   3.2 | -16.1   3.0  290  44 23   4.4   2.4
 17500 -16.2   2.8  290  41 21   6.1   3.3 | -15.5   4.1  290  44 22   4.7   2.6
 17000 -15.3   4.5  290  41 21   6.2   3.4 | -14.8   5.4  290  44 23   4.9   2.7
 16500 -14.4   6.1  290  41 21   6.4   3.5 | -14.0   6.8  285  44 23   5.1   2.8
 16000 -13.3   8.1  290  41 21   7.9   4.3 | -13.1   8.4  285  44 23   6.4   3.5
 15500 -12.2  10.0  290  42 22   8.1   4.5 | -12.2  10.0  285  43 22   6.2   3.4
 15000 -11.2  11.8  290  41 21   4.6   2.5 | -11.1  12.0  285  42 22   8.2   4.5
 14500 -10.5  13.1  290  40 21   4.9   2.7 |  -9.9  14.2  285  40 21   8.2   4.5
 14000  -9.8  14.4  285  38 20   4.7   2.6 |  -8.7  16.3  285  38 20   6.9   3.8
 13500  -9.1  15.6  285  36 18   4.7   2.6 |  -7.7  18.1  280  36 18   6.8   3.7
 13000  -8.4  16.9  285  33 17   5.0   2.8 |  -6.8  19.8  280  33 17   5.1   2.8
 12500  -7.6  18.3  280  30 16   5.2   2.8 |  -6.2  20.8  275  30 16   4.5   2.4
 12000  -6.9  19.6  280  27 14   5.9   3.2 |  -5.5  22.1  270  27 14   4.4   2.4
 11500  -5.9  21.4  275  24 12   6.2   3.4 |  -4.9  23.2  270  24 12   4.3   2.4
 11000  -5.0  23.0  270  21 11   6.1   3.4 |  -4.2  24.4  260  21 11   5.9   3.2
 10500  -4.1  24.6  270  18 10   6.3   3.5 |  -3.3  26.1  255  19 10   6.8   3.7
 10250  -3.7  25.3  265  17  9   5.2   2.9 |  -2.8  27.0  255  18  9   5.0   2.8
 10000  -3.4  25.9  265  16  8   4.1   2.3 |  -2.5  27.5  250  18  9   3.1   1.7
  9750  -3.0  26.6  260  15  8   5.0   2.8 |  -2.2  28.0  250  16  8   4.6   2.5
  9500  -2.6  27.3  260  14  7   6.0   3.3 |  -1.9  28.6  245  15  8   5.8   3.2
  9250  -2.2  28.0  255  13  7   4.1   2.3 |  -1.5  29.3  240  14  7   3.9   2.2
  9000  -2.0  28.4  250  12  6   2.0   1.1 |  -1.3  29.7  235  13  7   1.9   1.0
  8750  -1.8  28.8  245  11  6   2.5   1.4 |  -1.1  30.0  230  12  6   3.3   1.8
  8500  -1.6  29.1  240  10  5   2.7   1.5 |  -0.8  30.6  225  11  6   4.4   2.4
  8250  -1.4  29.5  230   9  5   3.8   2.1 |  -0.6  30.9  215  10  5   3.6   2.0
  8000  -1.0  30.2  225   8  4   4.4   2.4 |  -0.3  31.5  210  10  5   3.3   1.8
  7750  -0.7  30.7  215   7  4   4.6   2.5 |  -0.1  31.8  205  10  5   3.2   1.8
  7500  -0.3  31.5  210   6  3   4.3   2.4 |   0.2  32.4  200   9  5   3.4   1.9
  7250  -0.1  31.8  205   6  3   3.6   1.9 |   0.5  32.9  195   9  5   4.1   2.3
  7000   0.2  32.4  200   5  2   3.1   1.7 |   0.8  33.4  195   8  4   4.1   2.2
  6750   0.4  32.7  195   4  2   4.9   2.7 |   1.1  34.0  190   7  4   4.6   2.5
  6500   0.9  33.6  195   4  2   7.7   4.2 |   1.5  34.7  190   6  3   4.3   2.4
  6250   1.5  34.7  200   3  2   7.9   4.3 |   1.7  35.1  190   4  2   3.5   1.9
  6000   2.0  35.6  210   2  1   7.7   4.2 |   2.0  35.6  200   2  1   4.1   2.2
  5750   2.7  36.9  225   2  1  10.6   5.8 |   2.3  36.1  255   1  1   2.6   1.4
  5500   3.6  38.5  225   2  1  15.6   8.6 |   2.3  36.1  260   1  1  -0.9  -0.5
  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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