Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 251242
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0642 MDT Wednesday, May 25, 2016

This forecast is for Wednesday, May 25, 2016:

If the trigger temperature of 66.8 F/19.3 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1034 ft/min (5.3 m/s)
   Maximum height of thermals.................. 16542 ft MSL (11257 ft AGL)

Forecast maximum temperature................... 74.0 F/23.8 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ 1630 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 12847 ft MSL (7562 ft AGL)
Thermal soaring outlook for Thursday 05/26..... Fair

Wave Soaring Index............................. Fair
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 18063 ft MSL (12778 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 25925 ft MSL (20640 ft AGL)
Wave soaring outlook for Thursday 05/26........ Poor

Remarks...

Sunrise/Sunset.................... 05:36:56 / 20:15:52 MDT
Total possible sunshine........... 14 hr 38 min 56 sec (878 min 56 sec)
Altitude of sun at 12:56:36 MDT... 71.34 degrees

Upper air data from rawinsonde observation taken on 05/25/2016 at 0600 MDT

Freezing level.................. 11975 ft MSL (6690 ft AGL)
Convective condensation level... 13654 ft MSL (8369 ft AGL)
Lifted condensation level....... 14746 ft MSL (9460 ft AGL)
Lifted index.................... -3.3
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  -54.6 -66.3   225   24   12   3.5   1.9  106.4 223.4    47.8      M    M
 45000  -54.3 -65.7   220   43   22   6.6   3.6   82.1 179.8    36.2      M    M
 40000  -49.0 -56.2   225   58   30   2.0   1.1   66.5 151.6    28.5      M    M
 38000  -50.7 -59.3   220   85   44   0.2   0.1   55.2 131.4    21.6      M    M
 36000  -52.2 -62.0   220   72   37   0.7   0.4   44.5 112.1    14.7      M    M
 34000  -52.1 -61.8   220   59   30   0.9   0.5   36.4  97.6     9.4      M    M
 32000  -49.1 -56.4   220   49   25   7.3   4.0   32.4  90.4     6.7      M    M
 30000  -43.9 -47.0   220   42   22   9.4   5.2   31.7  89.1     6.3      M    M
 29000  -41.0 -41.8   220   43   22   9.4   5.2   31.5  88.7     6.2      M    M
 28000  -37.6 -35.7   220   44   23   7.3   4.0   31.2  88.2     6.1      M    M
 27000  -35.4 -31.7   235   45   23   7.4   4.1   30.2  86.4     5.4      M    M
 26000  -33.2 -27.8   245   48   25   7.6   4.2   29.4  84.9     4.8      M    M
 25000  -30.5 -22.9   240   48   25   9.3   5.1   29.1  84.4     4.6      M    M
 24000  -28.0 -18.4   240   49   25   7.5   4.1   28.7  83.6     4.3      M    M
 23000  -25.3 -13.5   240   48   25   8.8   4.8   28.3  82.9     4.0      M    M
 22000  -22.7  -8.9   235   48   25   8.9   4.9   28.0  82.3     3.8      M    M
 21000  -20.1  -4.2   235   47   24   8.7   4.7   27.8  82.0     3.6      M    M
 20000  -17.6   0.3   235   47   24   8.2   4.5   27.3  81.1     3.3      M    M
 19500  -16.3   2.7   235   46   24   8.4   4.6   27.0  80.6     3.0      M    M
 19000  -15.0   5.0   240   45   23   8.4   4.6   26.8  80.2     2.9      M    M
 18500  -14.1   6.6   240   44   23   5.0   2.7   26.2  79.2     2.5      M    M
 18000  -13.7   7.3   240   45   23   1.5   0.8   24.9  76.9     1.4      M    M
 17500  -12.8   9.0   245   45   23   8.4   4.6   24.3  75.8     0.8      M    M
 17000  -11.5  11.3   245   46   24   8.0   4.4   24.0  75.3     0.6      M    M
 16500  -10.6  12.9   245   43   22   4.8   2.7   23.4  74.2     0.1      M    M
 16000   -9.9  14.2   245   40   20   5.2   2.9   22.7  72.8    -0.6   1000  5.1
 15500   -9.1  15.6   245   36   19   5.5   3.0   21.9  71.4    -1.4    963  4.9
 15000   -8.4  16.9   250   33   17   6.9   3.8   21.2  70.2    -2.1    926  4.7
 14500   -7.1  19.2   250   29   15   9.6   5.3   21.1  70.0    -2.3    872  4.4
 14000   -4.9  23.2   255   25   13   9.6   5.2   21.1  69.9    -2.3    786  4.0
 13500   -3.5  25.7   260   23   12   9.1   5.0   21.0  69.8    -2.4    728  3.7
 13000   -2.6  27.3   260   20   11   5.5   3.0   20.5  69.0    -2.9    686  3.5
 12500   -1.4  29.5   255   18    9  10.8   5.9   20.3  68.6    -3.2    634  3.2
 12000    0.2  32.4   250   16    8  10.4   5.7   20.5  68.8    -3.1    573  2.9
 11500    1.7  35.1   245   13    7  10.3   5.7   20.5  69.0    -3.1    512  2.6
 11000    3.3  37.9   240   11    6  10.1   5.5   20.6  69.1    -3.0    451  2.3
 10500    4.6  40.3   235    8    4   9.0   4.9   20.6  69.0    -3.1    395  2.0
 10250    5.3  41.5   230    7    4   9.0   5.0   20.5  68.9    -3.2    368  1.9
 10000    5.9  42.6   210    4    2   8.7   4.8   20.5  68.8    -3.3    341  1.7
  9750    6.6  43.9   185    3    2   9.3   5.1   20.4  68.7    -3.4    315  1.6
  9500    7.2  45.0   155    3    2   7.3   4.0   20.3  68.6    -3.5    290  1.5
  9250    7.4  45.3   130    4    2   1.6   0.9   19.9  67.8    -4.0    274  1.4
  9000    7.5  45.5   110    5    3   5.5   3.0   19.3  66.7    -4.6    264  1.3
  8750    8.1  46.6   070    6    3   6.9   3.8   19.2  66.5    -4.7    238  1.2
  8500    8.3  46.9   050    9    5  -0.9  -0.5   18.6  65.5    -5.3    225  1.1
  8250    8.2  46.8   040   13    6  -0.1  -0.1   17.8  64.0    -6.1    221  1.1
  8000    8.4  47.1   035   16    8   5.2   2.8   17.2  63.0    -6.7    207  1.1
  7750    8.9  48.0   030   18    9   8.0   4.4   17.0  62.6    -6.9    185  0.9
  7500    9.4  48.9   030   20   10   2.8   1.5   16.8  62.2    -7.2    164  0.8
  7250    9.3  48.7   025   22   11  -1.2  -0.6   16.0  60.7    -8.0    158  0.8
  7000    9.3  48.7   025   24   12  -1.0  -0.6   15.2  59.3    -8.8    153  0.8
  6750    9.2  48.6   020   20   10   2.5   1.3   14.4  58.0    -9.6    147  0.7
  6500    9.6  49.3   020   16    8   8.0   4.4   14.1  57.4   -10.0    127  0.6
  6250   10.2  50.4   010   12    6   8.1   4.5   14.0  57.2   -10.1    103  0.5
  6000   10.8  51.4   355    8    4   8.1   4.4   13.9  57.0   -10.3     79  0.4
  5750   11.3  52.3   345    5    3   8.3   4.5   13.8  56.8   -10.5     55  0.3
  5500   11.4  52.5   310    3    1  -5.3  -2.9   13.3  56.0   -11.2     44  0.2

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

           05/25/2016 at 0900 MDT          |       05/25/2016 at 1200 MDT
                                           |
K index... -7.2  LI... +3.5                | K index... +6.8  LI... +2.1
CAPE... 0.0  CIN... M                      | 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 -55.0 -67.0  230  30 15   2.8   1.5 | -54.0 -65.2  225  27 14   3.3   1.8
 45000 -51.0 -59.8  230  53 28  -0.9  -0.5 | -49.9 -57.8  240  48 25  -2.6  -1.4
 40000 -52.0 -61.6  230  64 33  -0.6  -0.3 | -54.0 -65.2  240  66 34  -2.7  -1.5
 38000 -52.1 -61.8  235  65 33  -0.0  -0.0 | -53.8 -64.8  240  70 36   1.8   1.0
 36000 -52.1 -61.8  235  64 33  -0.0  -0.0 | -52.8 -63.0  240  72 37   1.8   1.0
 34000 -51.2 -60.2  235  63 32   5.8   3.2 | -50.9 -59.6  245  73 38   6.5   3.6
 32000 -47.6 -53.7  235  58 30   6.0   3.3 | -47.0 -52.6  245  70 36   6.6   3.6
 30000 -43.3 -45.9  235  53 27   7.0   3.8 | -42.2 -44.0  245  64 33   7.9   4.4
 29000 -41.2 -42.2  235  51 26   7.0   3.8 | -39.8 -39.6  245  61 31   7.9   4.4
 28000 -39.1 -38.4  235  49 25   7.0   3.8 | -37.4 -35.3  240  58 30   7.9   4.4
 27000 -36.9 -34.4  230  48 25   9.4   5.2 | -35.1 -31.2  240  55 28   7.1   3.9
 26000 -34.1 -29.4  230  47 24   9.2   5.0 | -33.0 -27.4  235  51 26   7.2   3.9
 25000 -31.4 -24.5  225  47 24   9.2   5.1 | -30.9 -23.6  235  48 25   7.2   3.9
 24000 -28.6 -19.5  220  46 24   9.2   5.0 | -28.6 -19.5  230  46 23   8.7   4.8
 23000 -25.9 -14.6  220  45 23   9.2   5.0 | -26.0 -14.8  230  44 23   8.9   4.9
 22000 -23.1  -9.6  225  44 23   9.2   5.0 | -23.3  -9.9  225  43 22   8.9   4.9
 21000 -20.5  -4.9  225  42 22   7.4   4.1 | -20.8  -5.4  230  42 22   7.3   4.0
 20000 -18.3  -0.9  235  38 20   7.5   4.1 | -18.6  -1.5  235  42 21   7.4   4.1
 19500 -17.2   1.0  235  37 19   7.5   4.1 | -17.5   0.5  240  42 21   7.4   4.1
 19000 -16.0   3.2  240  36 18   7.6   4.1 | -16.4   2.5  245  42 22   7.4   4.1
 18500 -14.9   5.2  245  34 18   7.4   4.1 | -15.2   4.6  250  42 22   7.4   4.1
 18000 -13.8   7.2  245  32 17   7.4   4.1 | -14.1   6.6  250  42 22   7.4   4.1
 17500 -12.7   9.1  250  30 16   7.5   4.1 | -13.0   8.6  255  41 21   7.3   4.0
 17000 -11.5  11.3  250  29 15   7.7   4.2 | -12.0  10.4  255  40 21   7.0   3.9
 16500 -10.4  13.3  255  29 15   7.7   4.2 | -11.0  12.2  255  38 20   7.1   3.9
 16000  -9.2  15.4  255  28 15   7.9   4.3 | -10.0  14.0  260  37 19   6.2   3.4
 15500  -7.4  18.7  260  29 15   7.8   4.3 |  -8.6  16.5  260  34 18   6.4   3.5
 15000  -6.3  20.7  260  29 15   7.0   3.8 |  -7.6  18.3  260  32 16   6.9   3.8
 14500  -5.3  22.5  265  29 15   7.0   3.9 |  -6.6  20.1  260  29 15   6.8   3.7
 14000  -4.2  24.4  265  29 15   7.1   3.9 |  -5.5  22.1  260  26 14   7.9   4.3
 13500  -3.2  26.2  270  28 15   7.1   3.9 |  -4.4  24.1  255  23 12   7.8   4.3
 13000  -2.2  28.0  270  28 14   6.4   3.5 |  -3.2  26.2  255  20 10   8.2   4.5
 12500  -1.2  29.8  275  27 14   6.4   3.5 |  -2.0  28.4  250  18  9   8.2   4.5
 12000  -0.3  31.5  275  27 14   6.0   3.3 |  -0.8  30.6  245  16  8   8.5   4.7
 11500   0.5  32.9  275  25 13   6.0   3.3 |   0.5  32.9  240  14  7   8.6   4.7
 11000   1.4  34.5  280  24 12   7.1   3.9 |   1.7  35.1  235  12  6   7.8   4.3
 10500   2.5  36.5  280  21 11   8.0   4.4 |   2.8  37.0  225  10  5   8.3   4.5
 10250   3.0  37.4  285  20 10   4.6   2.5 |   3.4  38.1  215   9  5   5.1   2.8
 10000   3.2  37.8  285  19 10   5.8   3.2 |   3.7  38.7  215   9  4   6.6   3.6
  9750   3.9  39.0  285  18  9  10.1   5.5 |   4.4  39.9  205   7  4  10.7   5.9
  9500   4.6  40.3  285  17  9   9.4   5.2 |   5.1  41.2  200   6  3   9.8   5.4
  9250   5.2  41.4  290  16  8   8.1   4.4 |   5.8  42.4  190   5  3   9.4   5.2
  9000   5.8  42.4  290  15  8   7.7   4.2 |   6.5  43.7  185   5  3   9.7   5.3
  8750   6.4  43.5  295  14  7   9.3   5.1 |   7.3  45.1  185   5  3  10.7   5.9
  8500   7.1  44.8  295  13  7   9.0   4.9 |   8.1  46.6  185   5  2  10.4   5.7
  8250   7.7  45.9  295  13  6   9.1   5.0 |   8.8  47.8  185   5  2  10.6   5.8
  8000   8.4  47.1  300  12  6   8.7   4.8 |   9.6  49.3  185   4  2  10.1   5.6
  7750   9.0  48.2  300  11  6   7.9   4.3 |  10.3  50.5  185   4  2   9.1   5.0
  7500   9.6  49.3  305  11  5   7.7   4.2 |  11.0  51.8  185   4  2   9.3   5.1
  7250  10.2  50.4  305  10  5   8.1   4.4 |  11.7  53.1  185   4  2  10.6   5.8
  7000  10.8  51.4  305   9  5   8.2   4.5 |  12.6  54.7  185   4  2  11.0   6.0
  6750  11.4  52.5  310   9  4   7.9   4.3 |  13.3  55.9  185   4  2   9.5   5.2
  6500  11.9  53.4  310   8  4   8.4   4.6 |  14.0  57.2  185   4  2   9.8   5.4
  6250  12.6  54.7  305   7  3   9.2   5.1 |  14.8  58.6  190   3  2  11.4   6.2
  6000  13.2  55.8  305   5  3   8.7   4.8 |  15.7  60.3  190   3  2  10.3   5.7
  5750  13.8  56.8  295   4  2  10.2   5.6 |  16.5  61.7  190   3  1  12.7   7.0
  5500  14.8  58.6  285   3  1  16.2   8.9 |  17.7  63.9  195   3  1  22.5  12.3

           05/25/2016 at 1500 MDT          |       05/25/2016 at 1800 MDT
                                           |
K index... +14.1  LI... -0.5               | K index... +10.3  LI... -1.0
CAPE... +43.2  CIN... -40.7                | CAPE... +149.9  CIN... -52.9
                                           |
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 -54.3 -65.7  230  33 17   2.8   1.5 | -54.8 -66.6  220  26 13   2.6   1.4
 45000 -50.7 -59.3  245  36 19  -1.7  -0.9 | -51.3 -60.3  235  16  8  -1.9  -1.1
 40000 -53.4 -64.1  245  62 32  -1.7  -1.0 | -53.8 -64.8  245  56 29  -1.5  -0.8
 38000 -53.1 -63.6  245  70 36   1.5   0.8 | -53.3 -63.9  245  66 34   1.8   1.0
 36000 -52.2 -62.0  245  77 39   1.5   0.8 | -52.3 -62.1  245  72 37   1.8   1.0
 34000 -50.6 -59.1  245  80 41   5.8   3.2 | -50.6 -59.1  245  76 39   5.5   3.0
 32000 -47.0 -52.6  245  76 39   5.9   3.3 | -47.2 -53.0  245  71 37   5.6   3.1
 30000 -42.5 -44.5  245  70 36   8.2   4.5 | -42.9 -45.2  245  65 33   7.9   4.3
 29000 -40.0 -40.0  245  67 34   8.2   4.5 | -40.5 -40.9  245  62 32   7.9   4.3
 28000 -37.5 -35.5  245  63 33   8.2   4.5 | -38.2 -36.8  245  58 30   7.9   4.3
 27000 -35.2 -31.4  245  60 31   7.0   3.9 | -35.9 -32.6  245  55 28   7.1   3.9
 26000 -33.0 -27.4  245  56 29   7.1   3.9 | -33.7 -28.7  245  53 27   7.2   3.9
 25000 -30.9 -23.6  245  52 27   7.1   3.9 | -31.6 -24.9  250  51 26   7.2   3.9
 24000 -28.8 -19.8  245  48 25   7.3   4.0 | -29.4 -20.9  250  48 25   8.2   4.5
 23000 -26.6 -15.9  245  47 24   7.4   4.0 | -26.9 -16.4  250  45 23   8.2   4.5
 22000 -24.4 -11.9  245  45 23   7.4   4.0 | -24.5 -12.1  250  41 21   8.2   4.5
 21000 -22.1  -7.8  245  43 22   8.1   4.4 | -22.0  -7.6  245  37 19   8.7   4.8
 20000 -19.8  -3.6  245  40 20   8.0   4.4 | -19.5  -3.1  245  32 16   8.7   4.8
 19500 -18.6  -1.5  245  38 20   8.1   4.4 | -18.2  -0.8  245  30 15   8.7   4.8
 19000 -17.4   0.7  245  36 19   8.0   4.4 | -16.9   1.6  245  27 14   8.6   4.7
 18500 -16.2   2.8  245  34 18   8.5   4.7 | -15.6   3.9  245  26 13   9.6   5.3
 18000 -14.9   5.2  245  32 16   8.5   4.7 | -14.2   6.4  240  24 13   9.5   5.2
 17500 -13.6   7.5  245  30 15   8.6   4.7 | -12.7   9.1  240  23 12   9.4   5.1
 17000 -12.4   9.7  240  28 14   8.6   4.7 | -11.4  11.5  240  22 11   9.3   5.1
 16500 -11.1  12.0  240  26 13   8.7   4.7 | -10.0  14.0  235  21 11   9.3   5.1
 16000  -9.1  15.6  235  23 12   8.9   4.9 |  -8.6  16.5  235  20 10   9.2   5.0
 15500  -7.8  18.0  235  22 11   9.0   4.9 |  -6.5  20.3  235  18  9   9.1   5.0
 15000  -6.4  20.5  235  21 11   9.1   5.0 |  -5.2  22.6  235  17  9   9.0   4.9
 14500  -5.1  22.8  230  19 10   9.1   5.0 |  -3.8  25.2  230  16  8   9.0   4.9
 14000  -3.7  25.3  230  18  9   8.7   4.8 |  -2.5  27.5  230  16  8   9.1   5.0
 13500  -2.4  27.7  225  17  9   8.7   4.8 |  -1.1  30.0  225  15  8   9.1   5.0
 13000  -1.1  30.0  225  16  8   8.9   4.9 |   0.2  32.4  220  14  7   8.9   4.9
 12500   0.2  32.4  220  15  8   8.9   4.9 |   1.5  34.7  220  13  7   8.9   4.9
 12000   1.5  34.7  215  14  7   9.0   4.9 |   2.9  37.2  215  12  6   9.0   4.9
 11500   2.9  37.2  210  12  6   9.1   5.0 |   4.2  39.6  210  11  6   9.1   5.0
 11000   4.1  39.4  205  11  6   7.4   4.1 |   5.5  41.9  200  10  5   7.7   4.2
 10500   5.2  41.4  200   9  5   6.5   3.6 |   6.6  43.9  195   8  4   6.9   3.8
 10250   5.7  42.3  195   8  4  10.2   5.6 |   7.2  45.0  195   8  4  10.2   5.6
 10000   6.6  43.9  190   6  3  10.9   6.0 |   8.0  46.4  185   6  3  10.5   5.8
  9750   7.2  45.0  190   5  3   7.7   4.2 |   8.6  47.5  180   5  3   7.5   4.1
  9500   7.8  46.0  185   4  2   8.5   4.7 |   9.2  48.6  175   4  2   8.5   4.6
  9250   8.4  47.1  175   4  2   8.5   4.7 |   9.8  49.6  160   3  1   7.9   4.3
  9000   9.1  48.4  175   3  2   9.7   5.3 |  10.3  50.5  140   2  1   8.3   4.5
  8750   9.8  49.6  175   3  1  10.2   5.6 |  11.0  51.8  105   1  1   9.0   4.9
  8500  10.5  50.9  175   2  1  10.1   5.5 |  11.6  52.9  060   1  1   8.7   4.8
  8250  11.3  52.3  170   2  1  10.1   5.6 |  12.2  54.0  035   2  1   9.3   5.1
  8000  12.1  53.8  175   2  1  10.0   5.5 |  12.9  55.2  025   3  1   9.8   5.4
  7750  12.8  55.0  175   2  1   9.7   5.3 |  13.6  56.5  020   3  2   9.5   5.2
  7500  13.5  56.3  180   1  1   9.8   5.4 |  14.3  57.7  015   3  2   9.6   5.3
  7250  14.3  57.7  185   1  1  10.1   5.5 |  15.1  59.2  010   3  2  10.3   5.7
  7000  15.0  59.0  185   1  1  10.3   5.7 |  15.9  60.6  005   4  2  10.6   5.8
  6750  15.8  60.4  190   1  0  10.1   5.5 |  16.6  61.9  005   4  2   9.0   5.0
  6500  16.5  61.7  205   1  0  10.4   5.7 |  17.3  63.1  360   4  2   9.2   5.1
  6250  17.3  63.1  220   1  0  11.1   6.1 |  18.0  64.4  360   4  2  10.7   5.9
  6000  18.1  64.6  000   0  0  10.6   5.8 |  18.8  65.8  355   4  2  10.7   5.9
  5750  19.0  66.2  000   0  0  12.0   6.6 |  19.6  67.3  355   4  2  10.4   5.7
  5500  20.1  68.2  280   1  0  20.3  11.1 |  20.4  68.7  355   4  2  12.7   7.0
________________________________________________________________________________

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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