Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 061337
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0637 MST Tuesday, December 6, 2016

This forecast is for Tuesday, December 6, 2016:

If the trigger temperature of 29.8 F/-1.2 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 174 ft/min (0.9 m/s)
   Maximum height of thermals.................. 9065 ft MSL (4065 ft AGL)

Forecast maximum temperature................... 30.0 F/-1.6 C
Time of trigger temperature.................... 1415 MST
Time of overdevelopment........................ 1400 MST
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 7450 ft MSL (2450 ft AGL)
Thermal soaring outlook for Wednesday 12/07.... Poor

Wave Soaring Index............................. Excellent
Wave Soaring Index trend (to 1700 MST)......... No change
Height of stable layer (12-18K ft MSL)......... 17296 ft MSL (12296 ft AGL)
Weak PVA/NVA (through 1700 MST)................ Weak PVA
Potential height of wave....................... 23689 ft MSL (18689 ft AGL)
Wave soaring outlook for Wednesday 12/07....... Good

Remarks...

Sunrise/Sunset.................... 07:06:43 / 16:34:56 MST
Total possible sunshine........... 9 hr 28 min 13 sec (568 min 13 sec)
Altitude of sun at 11:50:55 MST... 27.69 degrees

Upper air data from rawinsonde observation taken on 12/06/2016 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 16448 ft MSL (11448 ft AGL)
Lifted condensation level....... 12498 ft MSL (7498 ft AGL)
Lifted index.................... +14.9
K index......................... -2.3

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  -57.1 -70.8   260   69   36  -0.8  -0.5  110.8 231.5    63.0      M    M
 45000  -57.4 -71.3   255   81   41   2.8   1.5   85.1 185.1    51.9      M    M
 40000  -52.2 -62.0   260   80   41   0.9   0.5   68.8 155.8    45.2      M    M
 38000  -51.7 -61.1   260   83   43  -0.1  -0.1   60.7 141.2    41.0      M    M
 36000  -52.1 -61.8   265   90   46  -0.7  -0.4   51.1 124.0    35.6      M    M
 34000  -52.5 -62.5   270   95   49  -0.7  -0.4   42.2 108.0    30.3      M    M
 32000  -53.0 -63.4   265   87   45   3.8   2.1   33.3  92.0    24.7      M    M
 30000  -51.0 -59.8   270   86   44   3.3   1.8   28.1  82.5    21.5      M    M
 29000  -49.7 -57.5   275   88   45   7.0   3.9   25.9  78.6    20.2      M    M
 28000  -48.2 -54.8   275   89   46   3.3   1.8   23.9  75.1    19.0      M    M
 27000  -46.9 -52.4   275   90   46   7.7   4.2   20.9  69.6    16.9      M    M
 26000  -43.9 -47.0   275   90   47  10.0   5.5   21.0  69.8    17.2      M    M
 25000  -41.1 -42.0   275   91   47   8.0   4.4   20.9  69.6    17.4      M    M
 24000  -38.7 -37.7   275   92   47   8.1   4.5   20.2  68.4    17.1      M    M
 23000  -36.3 -33.3   275   93   48   7.4   4.0   19.6  67.4    16.8      M    M
 22000  -34.1 -29.4   280   94   48   7.2   3.9   18.7  65.7    16.2      M    M
 21000  -32.0 -25.6   280   91   47   7.2   3.9   17.7  63.9    15.6      M    M
 20000  -29.8 -21.6   280   88   45   7.1   3.9   16.8  62.3    15.0      M    M
 19500  -28.8 -19.8   280   86   44   6.8   3.7   16.4  61.4    14.7      M    M
 19000  -27.9 -18.2   280   85   44   5.1   2.8   15.6  60.1    14.2      M    M
 18500  -27.1 -16.8   285   83   43   5.1   2.8   14.8  58.6    13.6      M    M
 18000  -26.3 -15.3   285   81   42   4.7   2.6   14.0  57.2    13.0      M    M
 17500  -26.0 -14.8   285   78   40   0.5   0.3   12.7  54.8    11.9      M    M
 17000  -25.9 -14.6   280   73   38   2.2   1.2   11.1  52.0    10.6      M    M
 16500  -25.3 -13.5   275   71   36   3.8   2.1   10.1  50.2     9.8      M    M
 16000  -24.8 -12.6   270   68   35   4.0   2.2    9.1  48.4     9.0      M    M
 15500  -24.1 -11.4   270   65   34   5.6   3.1    8.2  46.8     8.2      M    M
 15000  -23.2  -9.8   270   62   32   6.1   3.3    7.6  45.7     7.6      M    M
 14500  -22.3  -8.1   265   59   30   6.1   3.4    7.0  44.6     7.1      M    M
 14000  -21.4  -6.5   265   56   29   6.6   3.6    6.4  43.6     6.7      M    M
 13500  -20.4  -4.7   265   51   26   6.7   3.7    5.9  42.7     6.2      M    M
 13000  -19.4  -2.9   265   46   24   6.7   3.7    5.4  41.7     5.8      M    M
 12500  -17.9  -0.2   260   38   20   6.7   3.7    4.7  40.4     5.2      M    M
 12000  -16.9   1.6   260   33   17   6.7   3.7    4.2  39.6     4.8      M    M
 11500  -15.9   3.4   260   30   16   6.7   3.7    3.7  38.7     4.3      M    M
 11000  -14.9   5.2   260   27   14   6.9   3.8    3.2  37.8     3.9      M    M
 10500  -14.1   6.6   270   22   11   1.6   0.9    2.5  36.5     3.2      M    M
 10250  -14.1   6.6   270   19   10  -0.5  -0.3    1.7  35.1     2.5      M    M
 10000  -14.1   6.6   280   17    9  -0.1  -0.0    0.9  33.7     1.8      M    M
  9750  -14.1   6.6   285   15    8   2.2   1.2    0.2  32.4     1.1      M    M
  9500  -13.8   7.2   290   14    7   4.1   2.3   -0.3  31.5     0.7      M    M
  9250  -13.5   7.7   290   13    7   3.6   2.0   -0.7  30.7     0.2      M    M
  9000  -13.2   8.2   295   12    6   3.7   2.1   -1.2  29.9    -0.2    266  1.4
  8750  -12.9   8.8   295   10    5   3.7   2.0   -1.7  29.0    -0.7    250  1.3
  8500  -12.7   9.1   290    7    4   3.7   2.0   -2.1  28.1    -1.2    234  1.2
  8250  -12.4   9.7   285    5    3   3.7   2.1   -2.6  27.3    -1.6    219  1.1
  8000  -12.1  10.2   270    3    1   3.6   2.0   -3.1  26.5    -2.1    203  1.0
  7750  -11.8  10.8   230    2    1   4.1   2.3   -3.5  25.6    -2.5    187  1.0
  7500  -11.6  11.1   180    2    1   2.1   1.2   -4.0  24.8    -3.0    172  0.9
  7250  -11.3  11.7   160    4    2   9.6   5.3   -4.5  23.9    -3.4    156  0.8
  7000  -11.0  12.2   150    5    3 -18.2 -10.0   -4.9  23.1    -3.9    140  0.7
  6750  -10.7  12.7   150    6    3  85.6  47.0   -5.4  22.3    -4.4    124  0.6
  6500  -10.4  13.3   150    8    4 -99.0 -54.3   -5.9  21.4    -4.8    109  0.6
  6250  -10.2  13.6   150    9    5 1144.4 627.8   -6.3  20.6    -5.3     93  0.5
  6000   -9.9  14.2   150   10    5 -99.0 -54.3   -6.8  19.8    -5.8     77  0.4
  5750   -9.6  14.7   150    8    4 15890.9 8718.4   -7.3  18.9    -6.3     62  0.3
  5500   -9.3  15.3   145    6    3 -99.0 -54.3   -7.7  18.1    -6.7     46  0.2

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

           12/06/2016 at 0800 MST          |       12/06/2016 at 1100 MST
                                           |
K index... -15.9  LI... +7.2               | K index... -10.7  LI... +7.5
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... M
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -56.0 -68.8  265  55 28   1.0   0.5 | -55.4 -67.7  265  62 32   0.4   0.2
 45000 -54.5 -66.1  270  77 40   1.0   0.5 | -54.8 -66.6  270  77 40   0.4   0.2
 40000 -54.4 -65.9  270  82 42  -0.2  -0.1 | -54.2 -65.6  270  85 44   0.4   0.2
 38000 -54.5 -66.1  270  83 42  -0.4  -0.2 | -53.9 -65.0  270  88 45  -0.2  -0.1
 36000 -55.1 -67.2  270  84 43  -0.9  -0.5 | -54.7 -66.5  270  86 44  -1.3  -0.7
 34000 -55.6 -68.1  270  85 44  -1.0  -0.5 | -55.4 -67.7  270  83 43  -1.3  -0.7
 32000 -54.9 -66.8  275  85 44   2.6   1.5 | -54.7 -66.5  265  81 42   2.9   1.6
 30000 -53.3 -63.9  275  85 44   2.6   1.4 | -53.0 -63.4  265  78 40   2.9   1.6
 29000 -52.0 -61.6  275  84 43   9.2   5.1 | -51.6 -60.9  265  76 39   9.0   4.9
 28000 -48.8 -55.8  270  77 40   8.6   4.7 | -48.5 -55.3  260  72 37   8.5   4.6
 27000 -46.2 -51.2  270  71 37   8.6   4.7 | -45.9 -50.6  260  69 35   8.5   4.6
 26000 -43.6 -46.5  270  68 35   8.1   4.5 | -43.4 -46.1  260  67 35   8.1   4.4
 25000 -41.2 -42.2  270  73 37   8.1   4.4 | -41.0 -41.8  260  70 36   8.0   4.4
 24000 -38.8 -37.8  275  78 40   8.1   4.4 | -38.6 -37.5  265  73 37   8.0   4.4
 23000 -36.4 -33.5  275  82 42   7.3   4.0 | -36.3 -33.3  270  75 39   7.2   3.9
 22000 -34.3 -29.7  275  81 41   7.2   3.9 | -34.2 -29.6  270  73 38   7.0   3.8
 21000 -32.2 -26.0  275  79 41   7.2   3.9 | -32.1 -25.8  270  71 37   7.0   3.8
 20000 -30.1 -22.2  275  77 39   6.7   3.7 | -30.0 -22.0  270  69 36   6.5   3.6
 19500 -29.1 -20.4  275  75 39   6.7   3.7 | -29.0 -20.2  270  68 35   6.6   3.6
 19000 -28.1 -18.6  275  74 38   6.7   3.7 | -28.1 -18.6  270  68 35   6.6   3.6
 18500 -27.1 -16.8  280  72 37   6.7   3.7 | -27.1 -16.8  270  67 35   6.6   3.6
 18000 -26.1 -15.0  280  70 36   6.6   3.6 | -26.1 -15.0  270  66 34   6.5   3.5
 17500 -25.1 -13.2  280  69 35   6.1   3.3 | -25.2 -13.4  270  65 34   5.4   3.0
 17000 -24.2 -11.6  280  67 34   6.1   3.4 | -24.4 -11.9  270  64 33   5.4   3.0
 16500 -23.3  -9.9  280  65 33   5.9   3.2 | -23.6 -10.5  275  63 32   6.2   3.4
 16000 -22.4  -8.3  280  63 32   5.8   3.2 | -22.6  -8.7  275  61 31   6.3   3.4
 15500 -21.6  -6.9  280  61 31   4.9   2.7 | -21.7  -7.1  275  59 30   6.2   3.4
 15000 -20.6  -5.1  280  57 29   4.1   2.3 | -20.3  -4.5  275  55 28   6.2   3.4
 14500 -20.0  -4.0  280  54 28   4.1   2.2 | -19.4  -2.9  275  52 27   5.5   3.0
 14000 -19.4  -2.9  280  51 26   4.1   2.2 | -18.6  -1.5  275  49 25   5.5   3.0
 13500 -18.8  -1.8  280  48 25   5.1   2.8 | -17.8  -0.0  275  45 23   5.1   2.8
 13000 -18.0  -0.4  280  45 23   5.4   3.0 | -17.1   1.2  275  41 21   5.0   2.7
 12500 -17.2   1.0  280  42 22   5.7   3.1 | -16.4   2.5  275  36 19   4.9   2.7
 12000 -16.4   2.5  275  37 19   5.8   3.2 | -15.7   3.7  275  31 16   4.9   2.7
 11500 -15.5   4.1  275  33 17   5.2   2.9 | -15.0   5.0  275  26 14   4.3   2.4
 11000 -14.8   5.4  275  29 15   5.3   2.9 | -14.4   6.1  275  21 11   4.2   2.3
 10500 -14.2   6.4  275  25 13   2.8   1.5 | -13.8   7.2  275  16  8   3.4   1.9
 10250 -14.0   6.8  275  23 12   1.8   1.0 | -13.6   7.5  275  14  7   3.1   1.7
 10000 -13.8   7.2  275  20 10   4.1   2.3 | -13.3   8.1  275  12  6   3.8   2.1
  9750 -13.4   7.9  270  18  9   3.9   2.2 | -13.0   8.6  275  10  5   4.2   2.3
  9500 -13.3   8.1  265  15  8   1.1   0.6 | -12.7   9.1  270   7  4   3.4   1.9
  9250 -13.2   8.2  260  13  7   0.8   0.4 | -12.5   9.5  255   5  3   3.6   2.0
  9000 -13.1   8.4  250  11  6   2.1   1.2 | -12.2  10.0  230   4  2   2.6   1.4
  8750 -12.9   8.8  240  10  5   4.2   2.3 | -12.0  10.4  185   4  2   4.9   2.7
  8500 -12.6   9.3  225   9  5   3.8   2.1 | -11.5  11.3  170   6  3   7.4   4.1
  8250 -12.3   9.9  215   9  5   3.6   2.0 | -11.0  12.2  160   8  4   7.2   3.9
  8000 -12.0  10.4  200  10  5   3.5   1.9 | -10.5  13.1  155  10  5   5.7   3.1
  7750 -11.7  10.9  195   9  5   3.8   2.1 | -10.1  13.8  150  12  6   3.9   2.1
  7500 -11.4  11.5  185   8  4   4.1   2.2 |  -9.8  14.4  145  13  7   4.0   2.2
  7250 -11.1  12.0  180   7  3   5.1   2.8 |  -9.5  14.9  140  13  7   5.2   2.9
  7000 -10.6  12.9  170   6  3   7.3   4.0 |  -8.9  16.0  135  13  7   9.7   5.3
  6750 -10.0  14.0  160   6  3   7.7   4.2 |  -8.1  17.4  135  13  7  10.8   5.9
  6500  -9.5  14.9  150   6  3   7.1   3.9 |  -7.4  18.7  135  13  7   9.5   5.2
  6250  -9.0  15.8  150   7  4   6.6   3.6 |  -6.6  20.1  135  13  7  10.2   5.6
  6000  -8.5  16.7  155   9  4   6.3   3.5 |  -5.9  21.4  135  12  6  10.6   5.8
  5750  -8.0  17.6  155  10  5   6.1   3.4 |  -5.1  22.8  135  12  6  10.0   5.5
  5500  -7.7  18.1  160  10  5   2.4   1.3 |  -4.3  24.3  135  11  6  13.4   7.3

           12/06/2016 at 1400 MST          |       12/06/2016 at 1700 MST
                                           |
K index... +5.8  LI... +5.8                | K index... +10.1  LI... +5.4
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.5
                                           |
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 -56.8 -70.2  260  52 27   0.3   0.2 | -56.8 -70.2  270  57 29   1.2   0.7
 45000 -56.3 -69.3  270  75 39   0.3   0.2 | -55.0 -67.0  275  69 35   1.2   0.7
 40000 -54.0 -65.2  270  83 43   1.8   1.0 | -52.4 -62.3  275  79 41   1.8   1.0
 38000 -52.9 -63.2  270  85 44   1.6   0.9 | -51.3 -60.3  275  83 43   0.7   0.4
 36000 -53.0 -63.4  270  83 43  -0.4  -0.2 | -51.6 -60.9  275  85 44  -0.7  -0.4
 34000 -53.3 -63.9  270  81 42  -0.4  -0.2 | -52.0 -61.6  270  87 45  -0.7  -0.4
 32000 -52.3 -62.1  270  81 42   2.6   1.4 | -51.5 -60.7  270  87 45   2.2   1.2
 30000 -50.8 -59.4  270  81 42   2.7   1.5 | -50.2 -58.4  270  85 44   2.2   1.2
 29000 -49.6 -57.3  265  80 41   5.9   3.2 | -49.4 -56.9  270  84 43   4.8   2.6
 28000 -47.9 -54.2  265  78 40   5.8   3.2 | -47.6 -53.7  270  83 42   4.8   2.6
 27000 -46.1 -51.0  260  76 39   5.8   3.2 | -46.1 -51.0  270  82 42   4.8   2.6
 26000 -44.4 -47.9  260  73 38   6.6   3.6 | -44.7 -48.5  270  81 42   5.4   3.0
 25000 -42.2 -44.0  260  73 37   7.3   4.0 | -42.9 -45.2  265  77 40   5.9   3.2
 24000 -40.0 -40.0  260  72 37   7.3   4.0 | -41.2 -42.2  265  74 38   5.9   3.2
 23000 -37.8 -36.0  265  71 37   7.3   4.0 | -39.4 -38.9  260  71 37   7.1   3.9
 22000 -35.6 -32.1  265  72 37   7.4   4.0 | -37.0 -34.6  260  66 34   8.1   4.5
 21000 -33.4 -28.1  265  73 37   7.4   4.1 | -34.6 -30.3  260  61 32   8.2   4.5
 20000 -31.3 -24.3  265  73 37   6.7   3.7 | -32.1 -25.8  260  57 29   8.7   4.8
 19500 -30.2 -22.4  265  72 37   6.8   3.7 | -30.8 -23.4  260  55 28   8.7   4.8
 19000 -29.2 -20.6  265  71 37   6.8   3.7 | -29.5 -21.1  260  54 28   8.7   4.8
 18500 -28.2 -18.8  265  71 36   6.8   3.7 | -28.2 -18.8  260  52 27   8.7   4.8
 18000 -26.7 -16.1  270  70 36   6.8   3.7 | -27.0 -16.6  260  51 26   8.7   4.8
 17500 -25.7 -14.3  270  67 35   6.8   3.7 | -25.7 -14.3  260  49 25   8.3   4.5
 17000 -24.7 -12.5  270  65 33   6.8   3.7 | -24.5 -12.1  255  47 24   8.3   4.6
 16500 -23.7 -10.7  270  61 31   6.5   3.6 | -23.2  -9.8  255  45 23   8.1   4.4
 16000 -22.7  -8.9  265  56 29   6.4   3.5 | -22.1  -7.8  255  41 21   8.0   4.4
 15500 -21.7  -7.1  265  52 27   8.1   4.5 | -20.9  -5.6  250  37 19   7.6   4.2
 15000 -20.5  -4.9  265  47 24   8.2   4.5 | -19.3  -2.7  250  33 17   7.0   3.8
 14500 -19.3  -2.7  265  42 22   7.0   3.8 | -18.3  -0.9  250  30 16   6.3   3.4
 14000 -18.3  -0.9  260  37 19   6.5   3.6 | -17.4   0.7  245  28 14   6.0   3.3
 13500 -17.4   0.7  260  32 17   5.5   3.0 | -16.6   2.1  245  25 13   4.8   2.6
 13000 -16.7   1.9  260  27 14   4.7   2.6 | -16.0   3.2  245  22 12   3.9   2.2
 12500 -16.0   3.2  255  22 11   4.1   2.3 | -15.4   4.3  240  20 10   3.1   1.7
 12000 -15.4   4.3  250  18  9   3.6   2.0 | -15.0   5.0  235  16  8   2.4   1.3
 11500 -14.9   5.2  245  15  8   3.2   1.8 | -14.7   5.5  230  13  7   2.0   1.1
 11000 -14.5   5.9  235  11  6   2.9   1.6 | -14.4   6.1  220  11  5   1.6   0.9
 10500 -14.0   6.8  215   8  4   3.1   1.7 | -14.2   6.4  205   9  5   1.8   1.0
 10250 -13.8   7.2  205   7  4   3.4   1.8 | -14.1   6.6  195   9  4   1.9   1.0
 10000 -13.5   7.7  195   7  3   3.0   1.6 | -13.9   7.0  185   9  5   2.1   1.2
  9750 -13.3   8.1  180   7  3   4.0   2.2 | -13.7   7.3  175  10  5   3.8   2.1
  9500 -12.9   8.8  165   7  4   6.2   3.4 | -13.4   7.9  165  11  6   4.8   2.6
  9250 -12.4   9.7  155   9  4   6.6   3.6 | -13.0   8.6  160  12  6   5.2   2.9
  9000 -11.9  10.6  145  10  5   6.4   3.5 | -12.7   9.1  160  13  7   3.2   1.7
  8750 -11.4  11.5  145  12  6   7.5   4.1 | -12.5   9.5  155  14  7   4.5   2.5
  8500 -10.8  12.6  140  12  6   8.5   4.7 | -11.9  10.6  155  14  7   8.1   4.4
  8250 -10.1  13.8  135  13  7   7.9   4.3 | -11.4  11.5  155  14  7   7.4   4.1
  8000  -9.5  14.9  130  13  7   9.5   5.2 | -10.8  12.6  155  14  7   8.5   4.7
  7750  -8.7  16.3  130  13  7  10.3   5.6 | -10.1  13.8  155  13  7   9.0   4.9
  7500  -8.0  17.6  130  13  7   9.2   5.1 |  -9.5  14.9  155  13  7   8.3   4.6
  7250  -7.3  18.9  130  13  7   9.3   5.1 |  -8.9  16.0  155  13  7   8.2   4.5
  7000  -6.6  20.1  130  13  7  10.8   5.9 |  -8.2  17.2  155  13  7   9.8   5.4
  6750  -5.7  21.7  125  13  7  10.4   5.7 |  -7.4  18.7  155  13  6  10.4   5.7
  6500  -5.1  22.8  125  13  7   8.3   4.5 |  -6.7  19.9  155  12  6   9.0   4.9
  6250  -4.4  24.1  125  13  7  10.0   5.5 |  -6.0  21.2  155  12  6  10.0   5.5
  6000  -3.5  25.7  125  12  6  12.3   6.8 |  -5.2  22.6  155  12  6  11.4   6.2
  5750  -2.7  27.1  125  12  6  10.3   5.7 |  -4.4  24.1  155  11  6  10.6   5.8
  5500  -1.9  28.6  125  11  6  11.2   6.1 |  -3.6  25.5  155  10  5  10.3   5.7
________________________________________________________________________________

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 near the old Stapleton
Airport site in Denver, Colorado at

                   North Latitude:  39 deg 46 min 5.016 sec
                   West Longitude: 104 deg 52 min 9.984 sec
                   Elevation: 5285 feet (1611 meters)

and may not be representative of other areas along the Front Range of the
Colorado Rocky Mountains.  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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