Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 231224
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0624 MDT Thursday, April 23, 2015

This forecast is for Thursday, April 23, 2015:

If the trigger temperature of 64.5 F/18.1 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1042 ft/min (5.3 m/s)
   Maximum height of thermals.................. 18083 ft MSL (12798 ft AGL)

Forecast maximum temperature................... 70.0 F/21.6 C
Time of trigger temperature.................... 1100 MDT
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9052 ft MSL (3767 ft AGL)
Thermal soaring outlook for Friday 04/24....... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 14386 ft MSL (9101 ft AGL)
Wave soaring outlook for Friday 04/24.......... Fair

Remarks... None

Sunrise/Sunset.................... 06:10:49 / 19:44:34 MDT
Total possible sunshine........... 13 hr 33 min 44 sec (813 min 44 sec)
Altitude of sun at 12:57:52 MDT... 62.84 degrees

Upper air data from rawinsonde observation taken on 04/23/2015 at 0600 MDT

Freezing level.................. 11637 ft MSL (6352 ft AGL)
Convective condensation level... 15643 ft MSL (10358 ft AGL)
Lifted condensation level....... 16030 ft MSL (10745 ft AGL)
Lifted index.................... -0.9
K index......................... +10.7

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -58.7 -73.7   255   44   23   6.5   3.6  102.3 216.2    46.4      M    M
 45000  -57.2 -71.0   240   46   24   4.8   2.6   78.9 174.0    35.4      M    M
 40000  -54.7 -66.5   235   54   28   0.1   0.0   59.8 139.7    25.4      M    M
 38000  -58.0 -72.4   240   61   31   1.6   0.9   46.1 115.0    16.8      M    M
 36000  -57.1 -70.8   240   56   29  -2.2  -1.2   38.8 101.9    12.3      M    M
 34000  -55.3 -67.5   235   39   20   2.5   1.4   33.0  91.4     8.5      M    M
 32000  -51.9 -61.4   240   27   14   7.1   3.9   29.6  85.3     6.2      M    M
 30000  -46.0 -50.8   245   27   14   8.0   4.4   28.7  83.6     5.7      M    M
 29000  -43.6 -46.5   250   27   14   8.1   4.4   28.0  82.4     5.3      M    M
 28000  -41.0 -41.8   250   27   14   9.2   5.1   27.6  81.7     5.0      M    M
 27000  -38.2 -36.8   255   28   14   9.2   5.1   27.4  81.3     4.9      M    M
 26000  -35.4 -31.7   255   28   14   9.3   5.1   27.3  81.1     4.9      M    M
 25000  -32.8 -27.0   250   28   14   8.7   4.8   26.9  80.5     4.7      M    M
 24000  -30.2 -22.4   245   28   14   8.5   4.7   26.5  79.7     4.4      M    M
 23000  -27.7 -17.9   245   28   14   8.3   4.6   25.9  78.6     3.9      M    M
 22000  -25.2 -13.4   245   28   14   8.3   4.6   25.3  77.6     3.5      M    M
 21000  -22.7  -8.9   245   27   14   8.8   4.8   24.9  76.9     3.2      M    M
 20000  -21.3  -6.3   245   27   14   4.8   2.6   23.3  73.9     1.8      M    M
 19500  -20.6  -5.1   245   25   13   4.3   2.3   22.4  72.3     1.0      M    M
 19000  -19.7  -3.5   245   22   11   8.0   4.4   21.8  71.2     0.5      M    M
 18500  -18.4  -1.1   245   20   10   9.4   5.1   21.6  70.9     0.3      M    M
 18000  -17.2   1.0   240   17    9   6.9   3.8   21.3  70.4    -0.0   1241  6.3
 17500  -16.1   3.0   245   17    9   8.4   4.6   20.9  69.6    -0.4   1194  6.1
 17000  -14.8   5.4   250   17    9   9.2   5.0   20.8  69.4    -0.5   1138  5.8
 16500  -13.4   7.9   260   17    9   9.3   5.1   20.7  69.3    -0.5   1082  5.5
 16000  -12.0  10.4   265   17    9   9.3   5.1   20.7  69.2    -0.6   1025  5.2
 15500  -10.6  12.9   270   19   10   9.3   5.1   20.6  69.0    -0.7    969  4.9
 15000   -8.5  16.7   280   23   12   9.3   5.1   20.4  68.8    -0.8    884  4.5
 14500   -7.1  19.2   280   26   13   9.3   5.1   20.4  68.6    -0.9    828  4.2
 14000   -5.8  21.6   285   28   15   8.4   4.6   20.2  68.4    -1.0    774  3.9
 13500   -4.5  23.9   285   30   16   8.5   4.7   20.0  68.0    -1.3    721  3.7
 13000   -3.3  26.1   290   32   17   8.5   4.7   19.8  67.7    -1.4    668  3.4
 12500   -2.0  28.4   290   34   18   8.6   4.7   19.7  67.4    -1.6    615  3.1
 12000   -0.7  30.7   290   35   18   8.6   4.7   19.5  67.1    -1.8    563  2.9
 11500    0.5  32.9   290   31   16   8.6   4.7   19.3  66.7    -2.1    510  2.6
 11000    1.8  35.2   290   27   14   8.6   4.7   19.0  66.3    -2.3    457  2.3
 10500    3.0  37.4   290   23   12   8.6   4.7   18.9  65.9    -2.5    405  2.1
 10250    3.7  38.7   290   21   11   8.6   4.7   18.8  65.8    -2.6    378  1.9
 10000    4.3  39.7   290   19   10   8.7   4.8   18.7  65.6    -2.7    352  1.8
  9750    5.0  41.0   290   18    9   8.8   4.8   18.6  65.5    -2.8    325  1.7
  9500    5.6  42.1   290   17    9   8.8   4.8   18.5  65.4    -2.9    298  1.5
  9250    6.3  43.3   285   17    9   8.8   4.8   18.5  65.2    -2.9    272  1.4
  9000    6.9  44.4   285   16    8   8.8   4.8   18.4  65.1    -3.0    245  1.2
  8750    7.5  45.5   285   16    8   8.8   4.8   18.3  65.0    -3.1    218  1.1
  8500    8.2  46.8   285   15    8   8.8   4.8   18.2  64.8    -3.2    191  1.0
  8250    8.8  47.8   285   15    8   8.8   4.8   18.2  64.7    -3.3    164  0.8
  8000    9.5  49.1   285   15    8   8.9   4.9   18.1  64.6    -3.4    138  0.7
  7750   10.1  50.2   285   14    7   8.6   4.7   18.0  64.4    -3.5    111  0.6
  7500   10.8  51.4   285   14    7   9.6   5.2   17.9  64.3    -3.6     84  0.4
  7250   11.4  52.5   290   13    7   6.1   3.3   17.9  64.2    -3.7     57  0.3
  7000   11.6  52.9   290   13    7   0.7   0.4   17.3  63.2    -4.3     45  0.2
  6750   11.6  52.9   285   12    6   0.4   0.2   16.6  61.9    -5.0     37  0.2
  6500   11.6  52.9   280   11    6   0.1   0.1   15.9  60.6    -5.8     30  0.2
  6250   11.6  52.9   270   10    5   1.7   0.9   15.2  59.3    -6.5     23  0.1
  6000   11.6  52.9   260    9    5  -4.2  -2.3   14.5  58.1    -7.3     15  0.1
  5750   10.8  51.4   250    6    3 -12.3  -6.7   13.0  55.4    -8.8     31  0.2
  5500    9.9  49.8   230    4    2  -9.9  -5.5   11.4  52.6   -10.5     52  0.3

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

           04/23/2015 at 0900 MDT          |       04/23/2015 at 1200 MDT
                                           |
K index... +8.4  LI... +272.9              | K index... +11.0  LI... +270.8
CAPE... +26.7  CIN... -157.0               | CAPE... +291.3  CIN... -28.9
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -58.5 -73.3  260  43 22   1.0   0.6 | -58.5 -73.3  255  39 20   1.1   0.6
 45000 -56.8 -70.2  255  47 24   0.8   0.5 | -56.8 -70.2  250  42 21   1.2   0.6
 40000 -56.0 -68.8  245  61 31   0.6   0.3 | -55.0 -67.0  245  66 34   1.2   0.7
 38000 -55.4 -67.7  245  60 31   1.3   0.7 | -54.2 -65.6  245  69 36   1.6   0.9
 36000 -54.6 -66.3  245  52 27   1.3   0.7 | -53.3 -63.9  245  65 34   1.6   0.9
 34000 -53.7 -64.7  245  44 23   4.9   2.7 | -52.0 -61.6  240  60 31   3.9   2.1
 32000 -50.1 -58.2  240  37 19   5.3   2.9 | -49.7 -57.5  240  49 25   3.8   2.1
 30000 -46.5 -51.7  235  32 17   8.3   4.6 | -46.9 -52.4  235  40 21   8.3   4.6
 29000 -44.0 -47.2  240  31 16   8.4   4.6 | -44.4 -47.9  235  39 20   8.3   4.5
 28000 -41.5 -42.7  240  30 15   8.4   4.6 | -41.9 -43.4  235  37 19   8.3   4.5
 27000 -39.0 -38.2  245  29 15   8.6   4.7 | -39.4 -38.9  235  36 19   8.7   4.8
 26000 -36.3 -33.3  245  28 14   8.8   4.8 | -36.6 -33.9  235  33 17   9.2   5.1
 25000 -33.7 -28.7  250  27 14   8.8   4.8 | -33.9 -29.0  235  30 15   9.2   5.1
 24000 -31.1 -24.0  250  25 13   8.4   4.6 | -31.1 -24.0  235  27 14   8.9   4.9
 23000 -28.9 -20.0  250  23 12   7.3   4.0 | -28.7 -19.7  240  23 12   7.8   4.3
 22000 -26.7 -16.1  250  21 11   7.3   4.0 | -26.4 -15.5  240  20 10   7.8   4.3
 21000 -24.5 -12.1  255  18  9   8.1   4.5 | -24.1 -11.4  245  16  8   7.3   4.0
 20000 -21.9  -7.4  255  18 10   8.5   4.6 | -22.0  -7.6  250  17  9   7.1   3.9
 19500 -20.7  -5.3  260  19 10   8.5   4.6 | -20.9  -5.6  255  18  9   7.1   3.9
 19000 -19.4  -2.9  260  19 10   8.5   4.6 | -19.9  -3.8  255  18  9   7.2   4.0
 18500 -18.1  -0.6  260  19 10   8.4   4.6 | -18.8  -1.8  260  19 10   8.0   4.4
 18000 -16.9   1.6  265  19 10   8.4   4.6 | -17.5   0.5  260  20 10   8.9   4.9
 17500 -15.6   3.9  265  20 10   8.4   4.6 | -16.1   3.0  265  21 11   8.9   4.9
 17000 -14.4   6.1  265  20 10   8.8   4.8 | -14.1   6.6  265  21 11   9.2   5.1
 16500 -12.4   9.7  270  20 11   8.7   4.8 | -12.7   9.1  265  21 11   9.2   5.1
 16000 -11.1  12.0  270  21 11   8.6   4.7 | -11.4  11.5  265  19 10   8.9   4.9
 15500  -9.8  14.4  275  21 11   8.6   4.7 | -10.0  14.0  265  18  9   8.9   4.9
 15000  -8.6  16.5  275  21 11   8.5   4.7 |  -8.7  16.3  265  16  8   9.2   5.1
 14500  -7.3  18.9  280  20 11   8.5   4.7 |  -7.3  18.9  260  15  8   9.2   5.1
 14000  -6.0  21.2  280  20 10   8.8   4.8 |  -6.0  21.2  260  14  7   9.1   5.0
 13500  -4.7  23.5  285  20 11   8.9   4.9 |  -4.6  23.7  265  14  7   9.1   5.0
 13000  -3.4  25.9  285  20 11   8.7   4.8 |  -3.3  26.1  270  14  7   9.1   5.0
 12500  -2.1  28.2  285  20 10   8.6   4.7 |  -1.9  28.6  275  14  7   9.1   5.0
 12000  -0.9  30.4  285  20 10   8.5   4.7 |  -0.6  30.9  280  14  7   8.7   4.8
 11500   0.4  32.7  290  20 10   8.5   4.7 |   0.6  33.1  285  13  7   8.3   4.5
 11000   1.7  35.1  290  20 10   7.8   4.3 |   1.9  35.4  285  12  6   7.8   4.3
 10500   2.7  36.9  285  20 10   6.5   3.6 |   2.9  37.2  290  11  6   6.7   3.7
 10250   3.2  37.8  285  19 10   9.8   5.4 |   3.5  38.3  290  11  6   9.8   5.4
 10000   4.1  39.4  285  19 10  10.6   5.8 |   4.3  39.7  290  11  6  10.1   5.5
  9750   4.7  40.5  285  18  9   7.8   4.3 |   4.9  40.8  290  10  5   7.2   3.9
  9500   5.3  41.5  285  18  9   8.5   4.7 |   5.4  41.7  290   9  4   8.1   4.4
  9250   5.9  42.6  285  17  9   8.6   4.7 |   6.0  42.8  290   8  4   7.5   4.1
  9000   6.5  43.7  280  16  8   8.0   4.4 |   6.6  43.9  285   6  3   8.4   4.6
  8750   7.1  44.8  280  16  8   7.3   4.0 |   7.2  45.0  275   5  3   9.3   5.1
  8500   7.6  45.7  280  15  8   7.3   4.0 |   7.8  46.0  270   5  2   8.9   4.9
  8250   8.2  46.8  275  14  7   8.1   4.4 |   8.5  47.3  260   4  2   9.7   5.3
  8000   8.8  47.8  275  13  7   8.7   4.8 |   9.2  48.6  250   4  2  10.5   5.7
  7750   9.3  48.7  275  12  6   6.9   3.8 |  10.0  50.0  245   4  2   9.8   5.4
  7500   9.8  49.6  275  11  6   5.9   3.2 |  10.7  51.3  245   4  2   9.3   5.1
  7250  10.2  50.4  270  11  5   6.6   3.6 |  11.4  52.5  245   4  2   9.9   5.4
  7000  10.7  51.3  270   9  5   7.1   3.9 |  12.1  53.8  245   4  2  10.5   5.7
  6750  11.2  52.2  265   8  4   6.5   3.6 |  12.9  55.2  240   4  2  10.1   5.5
  6500  11.6  52.9  260   7  4   5.4   3.0 |  13.7  56.7  240   3  2  10.0   5.5
  6250  11.8  53.2  255   6  3   1.9   1.0 |  14.4  57.9  240   3  2  10.7   5.9
  6000  11.8  53.2  245   6  3   0.8   0.5 |  15.2  59.4  240   3  2  11.6   6.3
  5750  11.8  53.2  235   6  3  -2.7  -1.5 |  16.1  61.0  240   3  2   9.7   5.3
  5500  11.3  52.3  220   6  3  -5.0  -2.7 |  16.8  62.2  245   3  2  12.9   7.1

           04/23/2015 at 1500 MDT          |       04/23/2015 at 1800 MDT
                                           |
K index... +20.9  LI... +271.2             | K index... +23.4  LI... +271.2
CAPE... +298.8  CIN... -13.0               | CAPE... +305.1  CIN... -51.8
                                           |
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 -58.3 -72.9  245  39 20   1.7   0.9 | -58.0 -72.4  245  44 23   1.3   0.7
 45000 -55.7 -68.3  245  44 23   1.1   0.6 | -56.1 -69.0  245  46 23   1.1   0.6
 40000 -55.1 -67.2  240  68 35   0.4   0.2 | -54.8 -66.6  240  64 33   0.8   0.5
 38000 -54.6 -66.3  240  72 37   1.2   0.6 | -54.5 -66.1  240  64 33   0.1   0.1
 36000 -53.9 -65.0  240  68 35   1.2   0.6 | -54.5 -66.1  235  54 28   0.1   0.1
 34000 -52.7 -62.9  240  62 32   5.5   3.0 | -53.7 -64.7  235  44 22   6.8   3.7
 32000 -49.5 -57.1  235  49 25   5.3   2.9 | -49.8 -57.6  225  33 17   6.4   3.5
 30000 -46.0 -50.8  230  39 20   8.1   4.4 | -45.6 -50.1  215  24 13   9.1   5.0
 29000 -43.6 -46.5  235  38 20   8.1   4.4 | -42.9 -45.2  220  23 12   9.1   5.0
 28000 -41.1 -42.0  235  37 19   8.1   4.4 | -40.1 -40.2  220  22 12   9.1   5.0
 27000 -38.7 -37.7  235  36 19   8.4   4.6 | -37.4 -35.3  220  22 11   8.9   4.9
 26000 -36.1 -33.0  235  34 18   8.8   4.8 | -34.9 -30.8  220  21 11   8.5   4.6
 25000 -33.4 -28.1  235  33 17   8.8   4.8 | -32.3 -26.1  220  20 10   8.5   4.7
 24000 -30.8 -23.4  235  31 16   8.7   4.8 | -29.8 -21.6  215  19 10   8.4   4.6
 23000 -28.4 -19.1  235  28 15   8.1   4.4 | -27.5 -17.5  215  18  9   7.8   4.3
 22000 -25.9 -14.6  235  25 13   8.1   4.4 | -25.1 -13.2  220  17  9   7.8   4.3
 21000 -23.5 -10.3  235  21 11   7.9   4.3 | -22.8  -9.0  220  16  8   7.6   4.2
 20000 -21.3  -6.3  230  19 10   7.7   4.2 | -20.6  -5.1  220  14  7   7.5   4.1
 19500 -20.1  -4.2  230  18  9   7.7   4.2 | -19.5  -3.1  225  13  7   7.5   4.1
 19000 -19.0  -2.2  225  17  9   7.7   4.2 | -18.4  -1.1  225  12  6   7.5   4.1
 18500 -17.8  -0.0  225  16  8   7.7   4.2 | -17.3   0.9  225  11  6   7.4   4.0
 18000 -16.7   1.9  225  15  8   7.8   4.3 | -16.2   2.8  225  10  5   7.0   3.8
 17500 -15.0   5.0  220  14  7   7.8   4.3 | -15.2   4.6  220   9  5   7.0   3.8
 17000 -13.8   7.2  215  13  7   8.0   4.4 | -13.6   7.5  215   8  4   7.6   4.2
 16500 -12.6   9.3  215  12  6   8.0   4.4 | -12.5   9.5  210   7  4   7.6   4.1
 16000 -11.4  11.5  210  11  6   8.7   4.8 | -11.3  11.7  200   6  3   8.1   4.5
 15500 -10.1  13.8  210  11  6   8.6   4.7 | -10.1  13.8  195   6  3   8.1   4.4
 15000  -8.8  16.2  205  10  5   8.7   4.7 |  -8.9  16.0  190   5  3   7.9   4.3
 14500  -7.5  18.5  205  10  5   8.7   4.7 |  -7.8  18.0  190   5  3   7.9   4.3
 14000  -6.2  20.8  205   9  5   9.1   5.0 |  -6.6  20.1  190   5  2   8.0   4.4
 13500  -4.8  23.4  200   9  5   9.2   5.1 |  -5.4  22.3  190   4  2   8.1   4.4
 13000  -3.4  25.9  200   8  4   9.2   5.0 |  -4.2  24.4  195   4  2   8.0   4.4
 12500  -2.1  28.2  200   7  4   9.1   5.0 |  -3.1  26.4  195   4  2   7.7   4.2
 12000  -0.7  30.7  200   6  3   9.2   5.1 |  -1.9  28.6  200   4  2   8.1   4.4
 11500   0.7  33.3  205   6  3   9.4   5.2 |  -0.6  30.9  200   5  2   9.2   5.1
 11000   2.1  35.8  205   5  3   8.9   4.9 |   0.7  33.3  205   5  3   9.2   5.1
 10500   3.3  37.9  215   5  2   7.5   4.1 |   2.1  35.8  205   6  3   9.2   5.0
 10250   3.8  38.8  220   4  2   9.3   5.1 |   2.8  37.0  210   6  3  10.6   5.8
 10000   4.6  40.3  230   4  2  10.4   5.7 |   3.7  38.7  210   6  3  11.4   6.2
  9750   5.3  41.5  240   4  2   9.1   5.0 |   4.4  39.9  215   6  3   9.6   5.3
  9500   5.9  42.6  245   4  2   9.4   5.2 |   5.1  41.2  215   7  3   9.2   5.0
  9250   6.6  43.9  250   5  2   8.8   4.8 |   5.8  42.4  220   7  4   9.6   5.3
  9000   7.2  45.0  255   5  2   9.1   5.0 |   6.5  43.7  220   7  4   8.4   4.6
  8750   8.0  46.4  255   5  3  10.0   5.5 |   7.0  44.6  225   7  4   7.0   3.9
  8500   8.7  47.7  260   5  3   9.6   5.3 |   7.6  45.7  230   8  4   7.1   3.9
  8250   9.4  48.9  260   5  3  10.3   5.6 |   8.1  46.6  235   8  4   7.3   4.0
  8000  10.2  50.4  265   6  3  11.0   6.0 |   8.6  47.5  245   9  5   8.0   4.4
  7750  11.0  51.8  265   6  3  10.0   5.5 |   9.2  48.6  250  10  5   6.6   3.6
  7500  11.7  53.1  265   6  3   9.3   5.1 |   9.6  49.3  255  11  6   5.3   2.9
  7250  12.4  54.3  265   6  3   9.8   5.4 |  10.0  50.0  260  13  6   5.7   3.1
  7000  13.2  55.8  270   6  3  10.4   5.7 |  10.4  50.7  260  14  7   5.9   3.2
  6750  13.9  57.0  270   6  3  10.1   5.5 |  10.8  51.4  265  15  8   6.6   3.6
  6500  14.7  58.5  270   6  3   9.8   5.4 |  11.3  52.3  265  16  8   6.5   3.6
  6250  15.4  59.7  270   7  3  10.4   5.7 |  11.8  53.2  265  17  9   8.3   4.6
  6000  16.2  61.2  270   7  3  11.1   6.1 |  12.5  54.5  270  17  9  10.3   5.7
  5750  17.0  62.6  275   7  3   9.7   5.3 |  13.1  55.6  270  16  8   9.3   5.1
  5500  17.8  64.0  275   6  3  13.5   7.4 |  13.9  57.0  270  15  8  11.7   6.4
________________________________________________________________________________

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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