Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
011
UXUS97 KBOU 221230
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0630 MDT Friday, July 22, 2016

This forecast is for Friday, July 22, 2016:

If the trigger temperature of 88.2 F/31.2 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1459 ft/min (7.4 m/s)
   Maximum height of thermals.................. 18535 ft MSL (13250 ft AGL)

Forecast maximum temperature................... 96.0 F/36.0 C
Time of trigger temperature.................... 1030 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 13766 ft MSL (8481 ft AGL)
Thermal soaring outlook for Saturday 07/23..... Good

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....................... 14389 ft MSL (9104 ft AGL)
Wave soaring outlook for Saturday 07/23........ Poor

Remarks...

Sunrise/Sunset.................... 05:50:08 / 20:21:59 MDT
Total possible sunshine........... 14 hr 31 min 50 sec (871 min 50 sec)
Altitude of sun at 13:05:55 MDT... 70.27 degrees

Upper air data from rawinsonde observation taken on 07/22/2016 at 0600 MDT

Freezing level.................. 16867 ft MSL (11582 ft AGL)
Convective condensation level... 16987 ft MSL (11702 ft AGL)
Lifted condensation level....... 17412 ft MSL (12126 ft AGL)
Lifted index.................... -1.0
K index......................... +25.5

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  -66.3 -87.3   255   15    8   5.7   3.1   80.8 177.5    26.5      M    M
 45000  -61.0 -77.8   250   20   10   8.3   4.6   64.1 147.4    18.0      M    M
 40000  -51.2 -60.2   280   20   10   6.0   3.3   56.7 134.1    14.3      M    M
 38000  -46.6 -51.9   260   28   14   7.2   4.0   54.9 130.8    13.4      M    M
 36000  -41.6 -42.9   240   24   12   8.4   4.6   53.6 128.5    12.8      M    M
 34000  -36.8 -34.2   235   24   13   7.5   4.1   52.2 126.0    12.1      M    M
 32000  -31.9 -25.4   240   23   12   6.9   3.8   50.9 123.6    11.4      M    M
 30000  -26.9 -16.4   240   20   10   7.6   4.2   48.9 120.0    10.1      M    M
 29000  -24.4 -11.9   240   18    9   8.0   4.4   48.3 119.0     9.8      M    M
 28000  -22.4  -8.3   245   17    9   8.6   4.7   47.2 117.0     9.0      M    M
 27000  -20.0  -4.0   245   15    8   8.4   4.6   46.6 115.9     8.6      M    M
 26000  -17.6   0.3   250   14    7   6.4   3.5   46.0 114.7     8.2      M    M
 25000  -15.6   3.9   250   13    7   7.1   3.9   44.9 112.8     7.3      M    M
 24000  -13.5   7.7   225   14    7   7.1   3.9   43.9 111.0     6.6      M    M
 23000  -11.1  12.0   230   16    8   7.8   4.3   43.3 109.9     6.1      M    M
 22000   -8.9  16.0   215   13    7   9.9   5.5   42.5 108.5     5.5      M    M
 21000   -8.9  16.0   190   12    6   7.0   3.8   39.3 102.7     2.6      M    M
 20000   -6.5  20.3   210   11    6   7.9   4.3   38.7 101.6     2.1      M    M
 19500   -5.3  22.5   200   11    6   5.4   2.9   38.4 101.1     1.9      M    M
 19000   -4.9  23.2   205   10    5   3.9   2.1   37.3  99.1     0.8      M    M
 18500   -4.2  24.4   210    9    5   6.4   3.5   36.5  97.6     0.0      M    M
 18000   -3.1  26.4   220    8    4   8.8   4.8   36.1  97.0    -0.3   1214  6.2
 17500   -1.8  28.8   215    8    4   8.6   4.7   35.9  96.6    -0.5   1161  5.9
 17000   -0.6  30.9   210    9    5   8.5   4.7   35.7  96.2    -0.7   1109  5.6
 16500    0.7  33.3   210    9    5   8.5   4.7   35.5  95.9    -0.9   1056  5.4
 16000    1.9  35.4   205   10    5   8.5   4.7   35.3  95.6    -1.1   1004  5.1
 15500    3.2  37.8   205   12    6   8.5   4.7   35.1  95.2    -1.3    951  4.8
 15000    5.0  41.0   200   15    8   6.7   3.7   34.7  94.5    -1.7    875  4.4
 14500    5.9  42.6   200   17    9   6.2   3.4   34.1  93.4    -2.3    833  4.2
 14000    6.8  44.2   200   19   10   6.2   3.4   33.5  92.3    -2.8    791  4.0
 13500    7.7  45.9   190   18    9   8.3   4.6   33.0  91.4    -3.4    748  3.8
 13000    9.2  48.6   180   18    9   9.5   5.2   33.0  91.3    -3.4    691  3.5
 12500   10.6  51.1   170   18    9   9.6   5.3   33.0  91.3    -3.5    633  3.2
 12000   12.0  53.6   160   19   10   9.6   5.3   33.0  91.3    -3.5    575  2.9
 11500   13.4  56.1   160   17    9   9.6   5.3   32.9  91.3    -3.6    518  2.6
 11000   14.9  58.8   160   15    8   9.7   5.3   32.9  91.2    -3.6    460  2.3
 10500   16.3  61.3   160   14    7   8.8   4.8   32.8  91.1    -3.7    404  2.1
 10250   16.9  62.4   160   14    7   8.5   4.6   32.7  90.9    -3.8    377  1.9
 10000   17.5  63.5   165   14    7   8.5   4.7   32.6  90.7    -3.9    351  1.8
  9750   18.2  64.8   165   14    7   8.5   4.7   32.5  90.6    -4.0    325  1.6
  9500   18.8  65.8   165   14    7   8.5   4.7   32.5  90.4    -4.1    298  1.5
  9250   19.4  66.9   170   14    7   8.7   4.8   32.4  90.3    -4.2    272  1.4
  9000   20.1  68.2   170   14    7   7.9   4.3   32.3  90.1    -4.3    245  1.2
  8750   20.6  69.1   175   14    7   6.7   3.7   32.1  89.7    -4.5    223  1.1
  8500   21.1  70.0   175   14    7   6.7   3.7   31.8  89.3    -4.8    201  1.0
  8250   21.6  70.9   180   14    7   6.7   3.7   31.6  88.9    -5.0    179  0.9
  8000   22.0  71.6   180   14    7   6.7   3.7   31.4  88.5    -5.3    157  0.8
  7750   22.5  72.5   190   13    7   6.7   3.7   31.1  88.0    -5.5    135  0.7
  7500   23.0  73.4   200   12    6   6.7   3.7   30.9  87.6    -5.8    113  0.6
  7250   23.5  74.3   215   12    6   6.8   3.7   30.7  87.2    -6.1     91  0.5
  7000   24.0  75.2   225   12    6   6.5   3.5   30.4  86.8    -6.3     69  0.3
  6750   24.5  76.1   225   12    6   7.7   4.2   30.2  86.4    -6.6     47  0.2
  6500   25.0  77.0   225   11    6   3.2   1.8   30.0  85.9    -6.8     25  0.1
  6250   24.9  76.8   220   11    5  -0.0  -0.0   29.2  84.6    -7.6     18  0.1
  6000   24.8  76.6   220   10    5  -3.8  -2.1   28.5  83.3    -8.5     13  0.1
  5750   24.2  75.6   210    8    4 -10.1  -5.5   27.1  80.8    -9.9     26  0.1
  5500   23.3  73.9   195    5    3  -9.3  -5.1   25.7  78.2   -11.5     45  0.2

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

           07/22/2016 at 0900 MDT          |       07/22/2016 at 1200 MDT
                                           |
K index... +31.2  LI... -4.0               | K index... +29.0  LI... -2.7
CAPE... +1038.2  CIN... -70.1              | CAPE... +553.1  CIN... -5.0
                                           |
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 -65.2 -85.4  230  11  6   1.4   0.8 | -65.3 -85.5  220  15  8   1.9   1.0
 45000 -60.3 -76.5  245  19 10   5.7   3.1 | -60.3 -76.5  235  20 10   5.2   2.9
 40000 -51.1 -60.0  265  24 12   7.9   4.3 | -51.4 -60.5  255  22 12   8.8   4.8
 38000 -46.4 -51.5  265  22 11   7.9   4.3 | -46.1 -51.0  250  22 11   8.8   4.8
 36000 -41.6 -42.9  260  20 10   8.0   4.4 | -40.8 -41.4  250  21 11   8.0   4.4
 34000 -36.8 -34.2  250  18  9   8.1   4.4 | -36.1 -33.0  245  19 10   8.0   4.4
 32000 -32.0 -25.6  245  16  8   8.6   4.7 | -30.7 -23.3  235  17  9   8.3   4.5
 30000 -26.8 -16.2  240  15  8   7.7   4.2 | -26.3 -15.3  235  16  8   7.4   4.1
 29000 -24.5 -12.1  235  14  7   7.7   4.2 | -24.1 -11.4  235  16  8   7.4   4.1
 28000 -22.3  -8.1  235  14  7   7.3   4.0 | -22.0  -7.6  235  15  8   7.0   3.9
 27000 -20.2  -4.4  235  14  7   7.3   4.0 | -19.9  -3.8  235  15  8   7.0   3.9
 26000 -18.0  -0.4  235  14  7   7.3   4.0 | -17.8  -0.0  235  16  8   7.0   3.9
 25000 -15.9   3.4  235  14  7   6.7   3.7 | -15.8   3.6  240  16  8   6.4   3.5
 24000 -14.0   6.8  235  14  7   6.7   3.7 | -13.9   7.0  240  16  8   6.4   3.5
 23000 -12.0  10.4  235  14  7   6.7   3.7 | -12.0  10.4  240  16  8   6.4   3.5
 22000 -10.1  13.8  235  13  7   5.9   3.2 | -10.2  13.6  240  16  8   6.3   3.5
 21000  -8.4  16.9  240  12  6   6.0   3.3 |  -8.3  17.1  240  14  7   6.3   3.5
 20000  -6.7  19.9  240  11  5   6.0   3.3 |  -6.5  20.3  235  13  7   6.4   3.5
 19500  -5.8  21.6  240  10  5   6.2   3.4 |  -5.6  21.9  235  13  7   6.4   3.5
 19000  -4.9  23.2  245  10  5   6.4   3.5 |  -4.6  23.7  235  12  6   6.4   3.5
 18500  -4.0  24.8  245   9  5   6.4   3.5 |  -3.7  25.3  230  12  6   6.4   3.5
 18000  -3.0  26.6  245   9  5   6.6   3.6 |  -2.7  27.1  230  12  6   6.5   3.6
 17500  -2.1  28.2  245   9  5   6.6   3.6 |  -1.8  28.8  230  11  6   6.6   3.6
 17000  -1.1  30.0  245   9  5   6.7   3.6 |  -0.8  30.6  225  11  6   6.7   3.7
 16500  -0.2  31.6  250  10  5   6.7   3.7 |   0.7  33.3  220  12  6   7.0   3.8
 16000   1.3  34.3  250  11  6   7.3   4.0 |   1.7  35.1  220  12  6   6.9   3.8
 15500   2.4  36.3  245  12  6   7.7   4.2 |   2.7  36.9  215  12  6   6.9   3.8
 15000   3.5  38.3  240  13  7   7.9   4.3 |   3.7  38.7  215  12  6   6.8   3.8
 14500   4.7  40.5  235  13  7   8.8   4.9 |   4.6  40.3  210  12  6   6.7   3.7
 14000   5.9  42.6  230  13  7   8.7   4.8 |   5.6  42.1  205  12  6   6.5   3.5
 13500   7.3  45.1  225  13  7   9.9   5.4 |   6.7  44.1  205  12  6   8.9   4.9
 13000   8.7  47.7  225  13  7   9.8   5.4 |   7.9  46.2  205  11  6   8.5   4.7
 12500  10.1  50.2  220  13  7   9.6   5.3 |   9.2  48.6  200  11  5  10.8   5.9
 12000  11.5  52.7  220  13  7   9.6   5.3 |  10.8  51.4  200  10  5  11.0   6.0
 11500  13.0  55.4  215  12  6   9.6   5.2 |  12.3  54.1  200   9  5  10.0   5.5
 11000  14.4  57.9  215  12  6   9.9   5.4 |  13.7  56.7  200   9  4  10.2   5.6
 10500  15.5  59.9  210  11  6   4.0   2.2 |  14.9  58.8  205   8  4   4.7   2.6
 10250  15.9  60.6  210  11  6   8.6   4.7 |  15.4  59.7  205   8  4   9.4   5.1
 10000  16.8  62.2  205  11  6  14.0   7.7 |  16.3  61.3  205   7  4  14.3   7.8
  9750  17.8  64.0  200  10  5  11.5   6.3 |  17.3  63.1  205   7  3  12.0   6.6
  9500  18.5  65.3  195  10  5   7.7   4.2 |  18.0  64.4  205   6  3   8.5   4.6
  9250  19.0  66.2  190  10  5   6.9   3.8 |  18.6  65.5  205   6  3   8.1   4.4
  9000  19.7  67.5  185  10  5  10.0   5.5 |  19.3  66.7  205   5  3  11.1   6.1
  8750  20.5  68.9  180   9  5  10.1   5.6 |  20.2  68.4  205   5  3  11.2   6.1
  8500  21.2  70.2  175   9  5   8.5   4.7 |  20.9  69.6  210   5  2  10.2   5.6
  8250  21.8  71.2  175   9  5   8.0   4.4 |  21.7  71.1  210   5  2  10.1   5.5
  8000  22.4  72.3  175   9  4   8.5   4.7 |  22.4  72.3  210   5  2  10.0   5.5
  7750  23.0  73.4  175   8  4   7.5   4.1 |  23.1  73.6  210   4  2   9.9   5.5
  7500  23.5  74.3  170   7  4   6.1   3.3 |  23.9  75.0  215   4  2  10.1   5.5
  7250  23.9  75.0  165   7  3   5.6   3.0 |  24.7  76.5  215   4  2   9.9   5.4
  7000  24.3  75.7  160   6  3   7.5   4.1 |  25.4  77.7  215   4  2  10.4   5.7
  6750  24.8  76.6  155   6  3   4.8   2.6 |  26.2  79.2  220   4  2  10.4   5.7
  6500  24.8  76.6  155   4  2   1.3   0.7 |  26.9  80.4  220   4  2  10.1   5.5
  6250  24.8  76.6  155   2  1   1.4   0.8 |  27.7  81.9  220   4  2   9.5   5.2
  6000  24.8  76.6  145   1  0   5.1   2.8 |  28.4  83.1  225   4  2  12.1   6.6
  5750  25.4  77.7  000   0  0  14.0   7.7 |  29.6  85.3  225   4  2  19.2  10.5
  5500  26.6  79.9  360   1  0  16.6   9.1 |  31.2  88.2  225   3  2  23.2  12.7

           07/22/2016 at 1500 MDT          |       07/22/2016 at 1800 MDT
                                           |
K index... +29.9  LI... -2.7               | K index... +30.2  LI... -1.5
CAPE... +339.0  CIN... -13.3               | CAPE... +59.1  CIN... -31.6
                                           |
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 -66.1 -87.0  220  18  9   1.9   1.0 | -66.5 -87.7  230  22 11   1.0   0.5
 45000 -60.6 -77.1  230  25 13   5.9   3.3 | -61.5 -78.7  230  28 14   6.4   3.5
 40000 -50.8 -59.4  245  28 14   8.7   4.8 | -51.0 -59.8  235  25 13   9.2   5.0
 38000 -45.6 -50.1  245  26 13   8.7   4.8 | -45.5 -49.9  235  24 13   9.2   5.0
 36000 -40.3 -40.5  245  24 13   8.5   4.7 | -40.0 -40.0  235  24 12   8.4   4.6
 34000 -35.2 -31.4  245  22 11   8.6   4.7 | -35.0 -31.0  235  22 11   8.5   4.6
 32000 -29.5 -21.1  245  20 10   8.1   4.5 | -29.9 -21.8  235  21 11   9.0   5.0
 30000 -25.2 -13.4  240  19 10   7.2   4.0 | -25.0 -13.0  235  18  9   7.4   4.1
 29000 -23.1  -9.6  240  18  9   7.2   4.0 | -22.8  -9.0  235  17  9   7.4   4.1
 28000 -21.1  -6.0  240  18  9   6.4   3.5 | -20.7  -5.3  240  16  8   6.8   3.7
 27000 -19.2  -2.6  240  17  9   6.4   3.5 | -18.7  -1.7  240  15  8   6.8   3.7
 26000 -17.3   0.9  235  17  9   6.4   3.5 | -16.7   1.9  245  14  7   6.8   3.7
 25000 -15.4   4.3  235  17  9   6.2   3.4 | -14.8   5.4  245  13  7   6.2   3.4
 24000 -13.6   7.5  240  17  9   6.2   3.4 | -12.9   8.8  250  12  6   6.2   3.4
 23000 -11.8  10.8  240  17  9   6.3   3.4 | -11.1  12.0  255  12  6   6.3   3.4
 22000 -10.0  14.0  245  16  8   6.0   3.3 |  -9.4  15.1  260  11  6   5.8   3.2
 21000  -8.3  17.1  245  15  8   6.0   3.3 |  -7.7  18.1  265  11  5   5.8   3.2
 20000  -6.5  20.3  245  14  7   6.1   3.3 |  -6.0  21.2  270  10  5   5.8   3.2
 19500  -5.7  21.7  250  13  7   6.3   3.4 |  -5.2  22.6  270  10  5   5.9   3.2
 19000  -4.7  23.5  250  12  6   6.5   3.6 |  -4.3  24.3  270  10  5   6.0   3.3
 18500  -3.8  25.2  250  12  6   6.5   3.6 |  -3.5  25.7  270  10  5   6.0   3.3
 18000  -2.8  27.0  255  11  6   7.0   3.9 |  -2.6  27.3  265   9  5   6.2   3.4
 17500  -1.8  28.8  255  10  5   7.1   3.9 |  -1.7  28.9  265   9  5   6.2   3.4
 17000  -0.7  30.7  255   9  5   7.4   4.0 |  -0.8  30.6  260   9  4   6.1   3.3
 16500   1.0  33.8  250   8  4   7.9   4.3 |   0.0  32.0  255   8  4   5.7   3.1
 16000   2.2  36.0  245   8  4   7.9   4.4 |   1.2  34.2  245   8  4   7.2   4.0
 15500   3.3  37.9  230   7  4   8.0   4.4 |   2.6  36.7  235   8  4   9.1   5.0
 15000   4.5  40.1  215   7  4   8.1   4.4 |   4.0  39.2  225   8  4   9.1   5.0
 14500   5.7  42.3  210   7  4   8.8   4.8 |   5.3  41.5  220   8  4   8.9   4.9
 14000   7.0  44.6  205   7  4   8.7   4.8 |   6.6  43.9  220   8  4   8.9   4.9
 13500   8.3  46.9  200   7  4   9.3   5.1 |   7.9  46.2  215   8  4   9.1   5.0
 13000   9.6  49.3  195   7  4   9.3   5.1 |   9.2  48.6  210   7  4   9.1   5.0
 12500  10.9  51.6  195   7  4   9.4   5.2 |  10.6  51.1  210   7  4   9.3   5.1
 12000  12.3  54.1  195   7  3   9.5   5.2 |  11.9  53.4  210   7  4   9.3   5.1
 11500  13.7  56.7  195   6  3   9.1   5.0 |  13.3  55.9  210   7  4   9.6   5.2
 11000  15.0  59.0  195   6  3   9.3   5.1 |  14.8  58.6  210   7  4   9.7   5.3
 10500  16.1  61.0  195   5  3   4.8   2.6 |  16.0  60.8  210   7  4   4.7   2.6
 10250  16.5  61.7  195   5  3   9.2   5.0 |  16.4  61.5  210   7  4   7.7   4.3
 10000  17.4  63.3  195   5  3  13.6   7.5 |  17.3  63.1  210   7  4  13.1   7.2
  9750  18.3  64.9  195   5  3  12.2   6.7 |  18.2  64.8  210   7  4  11.9   6.5
  9500  19.2  66.6  200   5  3   8.9   4.9 |  19.0  66.2  210   7  4   8.9   4.9
  9250  19.7  67.5  200   5  2   8.2   4.5 |  19.5  67.1  215   7  4   7.7   4.2
  9000  20.5  68.9  200   5  2  11.2   6.2 |  20.2  68.4  215   7  4  10.5   5.8
  8750  21.3  70.3  200   5  2  11.1   6.1 |  21.0  69.8  215   7  4  10.7   5.9
  8500  22.1  71.8  205   5  2  10.0   5.5 |  21.8  71.2  220   7  4   9.7   5.3
  8250  22.8  73.0  205   5  2   9.2   5.1 |  22.5  72.5  225   7  4   9.2   5.1
  8000  23.5  74.3  205   5  2  10.3   5.6 |  23.2  73.8  230   7  4   9.0   4.9
  7750  24.4  75.9  205   5  2  10.7   5.9 |  23.8  74.8  235   7  4   8.4   4.6
  7500  25.1  77.2  205   4  2  10.0   5.5 |  24.5  76.1  245   7  4   8.3   4.5
  7250  25.8  78.4  210   4  2   9.9   5.4 |  25.0  77.0  250   8  4   8.3   4.6
  7000  26.6  79.9  210   4  2   9.8   5.4 |  25.6  78.1  255   9  4   7.8   4.3
  6750  27.3  81.1  215   4  2  10.0   5.5 |  26.2  79.2  260  10  5   7.9   4.4
  6500  28.1  82.6  215   4  2  10.5   5.8 |  26.8  80.2  265  10  5   9.0   4.9
  6250  28.8  83.8  215   4  2  10.2   5.6 |  27.5  81.5  265  10  5   9.4   5.1
  6000  29.6  85.3  220   4  2  11.5   6.3 |  28.1  82.6  265  10  5   8.6   4.7
  5750  30.7  87.3  220   4  2  18.2  10.0 |  28.7  83.7  270  11  5  10.5   5.7
  5500  32.4  90.3  220   4  2  25.2  13.8 |  29.7  85.5  270   9  5  15.8   8.7
________________________________________________________________________________

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.