Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | 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
000
UXUS97 KBOU 311336
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0736 MDT Thursday, July 31, 2014

This forecast is for Thursday, July 31, 2014:

If the trigger temperature of 70.1 F/21.2 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 763 ft/min (3.9 m/s)
   Maximum height of thermals.................. 12593 ft MSL (7308 ft AGL)

Forecast maximum temperature................... 77.0 F/25.5 C
Time of trigger temperature.................... 1130 MDT
Time of overdevelopment........................ 1530 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 10097 ft MSL (4811 ft AGL)
Thermal soaring outlook for Friday 08/01....... 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)................ Neither
Potential height of wave....................... 17111 ft MSL (11826 ft AGL)
Wave soaring outlook for Friday 08/01.......... Poor

Remarks... Scattered showers and thunderstorms

Sunrise/Sunset.................... 05:57:35 / 20:14:25 MDT
Total possible sunshine........... 14 hr 16 min 50 sec (856 min 50 sec)
Altitude of sun at 13:05:47 MDT... 68.35 degrees

Upper air data from rawinsonde observation taken on 07/31/2014 at 0600 MDT

Freezing level.................. 14461 ft MSL (9176 ft AGL)
Convective condensation level... 11539 ft MSL (6254 ft AGL)
Lifted condensation level....... 12164 ft MSL (6879 ft AGL)
Lifted index.................... -1.8
K index......................... +29.5

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  -65.3 -85.5   295   28   15  10.4   5.7   84.2 183.6    34.5      M    M
 45000  -58.5 -73.3   295   39   20   2.9   1.6   71.1 159.9    28.7      M    M
 40000  -53.8 -64.8   290   71   37   5.5   3.0   55.4 131.8    20.3      M    M
 38000  -50.3 -58.5   290   67   35   8.2   4.5   52.0 125.7    18.5      M    M
 36000  -45.0 -49.0   290   64   33   9.2   5.1   51.2 124.1    18.4      M    M
 34000  -40.2 -40.4   295   57   29   7.8   4.3   49.6 121.3    17.8      M    M
 32000  -34.7 -30.5   305   50   26   8.3   4.5   48.3 118.9    17.3      M    M
 30000  -29.0 -20.2   300   46   24   8.1   4.4   48.0 118.4    17.5      M    M
 29000  -27.3 -17.1   300   44   23   5.7   3.1   46.4 115.5    16.5      M    M
 28000  -25.2 -13.4   300   42   22   7.3   4.0   45.4 113.7    15.9      M    M
 27000  -23.2  -9.8   295   41   21   7.6   4.2   44.1 111.4    15.1      M    M
 26000  -20.9  -5.6   295   39   20   7.5   4.1   43.2 109.8    14.6      M    M
 25000  -18.7  -1.7   295   37   19   7.4   4.1   42.5 108.5    14.1      M    M
 24000  -17.5   0.5   300   32   17  -2.0  -1.1   40.3 104.6    12.5      M    M
 23000  -17.4   0.7   295   28   14   5.4   3.0   37.1  98.7     9.9      M    M
 22000  -14.9   5.2   295   24   12   7.9   4.3   36.6  97.9     9.5      M    M
 21000  -13.0   8.6   290   19   10  14.9   8.2   35.6  96.1     8.6      M    M
 20000  -11.2  11.8   305   21   11   7.2   4.0   34.4  93.9     7.6      M    M
 19500  -10.0  14.0   300   20   10   7.7   4.2   34.2  93.6     7.4      M    M
 19000   -9.0  15.8   300   18    9   5.8   3.2   33.7  92.6     6.9      M    M
 18500   -8.2  17.2   300   16    8   5.7   3.2   33.0  91.4     6.3      M    M
 18000   -7.3  18.9   300   13    7   6.0   3.3   32.3  90.1     5.8      M    M
 17500   -6.4  20.5   295   14    7  12.9   7.1   31.7  89.1     5.3      M    M
 17000   -4.6  23.7   285   15    8   6.6   3.6   32.3  90.1     5.7      M    M
 16500   -3.6  25.5   290   15    8   6.7   3.7   31.7  89.1     5.2      M    M
 16000   -2.3  27.9   295   15    8   5.6   3.1   30.8  87.4     4.3      M    M
 15500   -1.5  29.3   300   14    7   5.6   3.1   30.1  86.2     3.7      M    M
 15000   -0.7  30.7   305   13    7   5.6   3.1   29.4  85.0     3.1      M    M
 14500    0.1  32.2   295   10    5   5.6   3.1   28.7  83.7     2.4      M    M
 14000    0.9  33.6   285    7    3   5.6   3.1   28.0  82.5     1.8      M    M
 13500    1.7  35.1   280    6    3   5.6   3.1   27.3  81.2     1.1      M    M
 13000    2.5  36.5   270    5    2   5.6   3.1   26.6  79.9     0.4      M    M
 12500    3.3  37.9   255    4    2   5.6   3.1   26.0  78.7    -0.2    550  2.8
 12000    4.2  39.6   240    3    1   6.0   3.3   25.3  77.6    -0.8    511  2.6
 11500    5.0  41.0   215    2    1   6.1   3.3   24.7  76.5    -1.4    470  2.4
 11000    5.9  42.6   190    2    1   6.1   3.3   24.1  75.5    -2.0    429  2.2
 10500    6.8  44.2   165    3    2   6.0   3.3   23.6  74.5    -2.6    388  2.0
 10250    7.2  45.0   170    3    2   6.6   3.6   23.3  73.9    -2.9    367  1.9
 10000    7.8  46.0   175    3    2   8.8   4.8   23.1  73.6    -3.1    343  1.7
  9750    8.5  47.3   180    3    2   8.2   4.5   23.1  73.5    -3.1    314  1.6
  9500    9.0  48.2   185    4    2   5.2   2.9   22.8  73.1    -3.4    292  1.5
  9250    9.3  48.7   185    4    2   4.3   2.4   22.4  72.4    -3.8    274  1.4
  9000    9.6  49.3   190    4    2   4.6   2.5   22.0  71.6    -4.2    257  1.3
  8750    9.9  49.8   180    5    2   4.1   2.2   21.6  70.9    -4.7    242  1.2
  8500   10.2  50.4   170    5    3   3.8   2.1   21.1  70.0    -5.1    227  1.2
  8250   10.6  51.1   165    6    3   6.4   3.5   20.7  69.3    -5.4    206  1.0
  8000   11.2  52.2   160    7    4   8.3   4.6   20.6  69.1    -5.5    180  0.9
  7750   11.8  53.2   155    7    4   8.0   4.4   20.5  68.8    -5.7    156  0.8
  7500   12.3  54.1   150    7    4   8.1   4.5   20.3  68.6    -5.9    132  0.7
  7250   12.9  55.2   145    7    4   8.0   4.4   20.2  68.4    -6.1    108  0.5
  7000   13.4  56.1   140    7    4   8.6   4.7   20.1  68.2    -6.3     84  0.4
  6750   14.0  57.2   140    6    3   6.6   3.6   20.0  67.9    -6.5     61  0.3
  6500   14.2  57.6   140    4    2   2.5   1.3   19.5  67.2    -7.0     45  0.2
  6250   14.3  57.7   140    3    1   1.4   0.8   18.9  66.1    -7.7     35  0.2
  6000   14.4  57.9   140    1    1   1.7   1.0   18.3  65.0    -8.4     26  0.1
  5750   14.5  58.1   140    1    0   1.7   0.9   17.7  63.9    -9.0     16  0.1
  5500   14.6  58.3   000    0    0   1.8   1.0   17.1  62.8    -9.7      6  0.0

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

           07/31/2014 at 0900 MDT          |       07/31/2014 at 1200 MDT
                                           |
K index... +28.9  LI... -0.4               | K index... +24.5  LI... -1.6
CAPE... +0.1  CIN... -28.8                 | CAPE... +121.9  CIN... -7.9
                                           |
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 -62.1 -79.8  305  25 13   1.8   1.0 | -61.5 -78.7  300  25 13   2.6   1.4
 45000 -59.0 -74.2  295  51 26   2.8   1.6 | -58.0 -72.4  295  51 26   2.0   1.1
 40000 -53.7 -64.7  295  79 40   7.1   3.9 | -53.8 -64.8  290  82 42   7.1   3.9
 38000 -49.4 -56.9  300  69 36   7.2   3.9 | -49.6 -57.3  295  73 38   7.1   3.9
 36000 -45.1 -49.2  305  60 31   7.1   3.9 | -45.3 -49.5  295  65 33   7.0   3.9
 34000 -40.1 -40.2  310  53 28   8.6   4.7 | -40.3 -40.5  300  53 27   8.5   4.7
 32000 -34.9 -30.8  310  47 24   8.6   4.7 | -35.2 -31.4  305  41 21   8.5   4.7
 30000 -30.4 -22.7  315  41 21   7.3   4.0 | -30.3 -22.5  305  36 19   8.0   4.4
 29000 -28.2 -18.8  315  39 20   7.3   4.0 | -27.9 -18.2  305  34 18   8.0   4.4
 28000 -26.0 -14.8  315  36 18   7.3   4.0 | -25.0 -13.0  305  32 16   6.9   3.8
 27000 -23.4 -10.1  310  33 17   7.2   3.9 | -23.0  -9.4  305  30 15   6.9   3.8
 26000 -21.2  -6.2  310  31 16   7.2   3.9 | -20.9  -5.6  305  28 15   6.9   3.8
 25000 -19.1  -2.4  310  30 15   7.0   3.9 | -18.9  -2.0  305  27 14   6.9   3.8
 24000 -17.1   1.2  305  30 15   6.7   3.7 | -16.9   1.6  310  26 14   7.0   3.8
 23000 -15.2   4.6  305  30 15   6.7   3.7 | -14.8   5.4  310  26 13   7.0   3.9
 22000 -13.3   8.1  300  30 15   6.3   3.4 | -12.8   9.0  310  26 13   6.6   3.6
 21000 -11.7  10.9  300  27 14   5.5   3.0 | -11.2  11.8  310  23 12   5.7   3.1
 20000 -10.1  13.8  300  24 12   5.6   3.1 |  -9.5  14.9  310  20 11   5.8   3.2
 19500  -9.3  15.3  300  22 12   5.5   3.0 |  -8.7  16.3  315  19 10   5.8   3.2
 19000  -8.5  16.7  300  21 11   7.0   3.8 |  -7.9  17.8  315  18  9   6.1   3.4
 18500  -7.5  18.5  300  20 10   6.8   3.8 |  -7.0  19.4  315  17  9   6.1   3.3
 18000  -6.5  20.3  300  19 10   6.4   3.5 |  -6.1  21.0  320  16  8   6.0   3.3
 17500  -5.6  21.9  300  18  9   6.0   3.3 |  -5.2  22.6  325  15  8   6.0   3.3
 17000  -4.8  23.4  300  17  9   6.1   3.3 |  -4.4  24.1  325  15  8   6.0   3.3
 16500  -4.0  24.8  300  15  8   5.4   2.9 |  -3.5  25.7  330  14  7   6.0   3.3
 16000  -3.2  26.2  300  14  7   5.4   3.0 |  -2.6  27.3  330  12  6   6.0   3.3
 15500  -2.4  27.7  305  12  6   5.7   3.1 |  -1.8  28.8  330  11  6   5.4   3.0
 15000  -1.6  29.1  305  11  5   5.8   3.2 |  -1.1  30.0  330   9  5   5.2   2.9
 14500  -0.8  30.6  305   9  5   6.2   3.4 |  -0.3  31.5  335   8  4   5.5   3.0
 14000   0.6  33.1  305   6  3   6.8   3.7 |   0.9  33.6  340   5  3   6.0   3.3
 13500   1.6  34.9  305   4  2   5.9   3.2 |   1.7  35.1  350   4  2   5.7   3.1
 13000   2.4  36.3  315   3  1   5.7   3.1 |   2.5  36.5  005   3  1   5.6   3.1
 12500   3.2  37.8  360   1  1   5.9   3.2 |   3.3  37.9  045   2  1   6.1   3.3
 12000   4.0  39.2  070   2  1   5.9   3.3 |   4.3  39.7  080   3  1   6.4   3.5
 11500   4.9  40.8  090   3  2   5.9   3.2 |   5.3  41.5  095   4  2   6.7   3.7
 11000   5.8  42.4  090   5  2   5.8   3.2 |   6.3  43.3  105   6  3   6.8   3.7
 10500   6.6  43.9  090   6  3   5.5   3.0 |   7.4  45.3  115   7  4   4.0   2.2
 10250   7.0  44.6  095   6  3   5.9   3.3 |   7.6  45.7  115   7  4   4.9   2.7
 10000   7.5  45.5  100   5  3   7.2   4.0 |   8.2  46.8  115   7  4  10.7   5.9
  9750   8.0  46.4  105   5  2   7.4   4.1 |   9.0  48.2  115   7  4  10.9   6.0
  9500   8.5  47.3  115   5  2   5.8   3.2 |   9.7  49.5  120   7  4   7.6   4.2
  9250   8.9  48.0  125   5  2   4.4   2.4 |  10.1  50.2  120   7  3   4.9   2.7
  9000   9.3  48.7  135   5  3   6.2   3.4 |  10.5  50.9  120   6  3   7.7   4.2
  8750   9.8  49.6  145   6  3   7.1   3.9 |  11.1  52.0  125   5  2   8.8   4.8
  8500  10.3  50.5  150   7  3   5.9   3.2 |  11.6  52.9  130   4  2   6.8   3.7
  8250  10.7  51.3  155   8  4   5.5   3.0 |  12.0  53.6  140   3  1   5.9   3.2
  8000  11.1  52.0  160   9  4   6.2   3.4 |  12.4  54.3  165   2  1   6.9   3.8
  7750  11.6  52.9  160  10  5   6.2   3.4 |  12.9  55.2  190   2  1   8.6   4.7
  7500  12.0  53.6  165  10  5   5.5   3.0 |  13.6  56.5  200   2  1   9.4   5.2
  7250  12.4  54.3  170  11  6   5.4   3.0 |  14.2  57.6  205   2  1   9.4   5.1
  7000  12.7  54.9  175  12  6   6.0   3.3 |  14.9  58.8  205   2  1   9.6   5.3
  6750  13.2  55.8  175  13  7   7.7   4.2 |  15.6  60.1  205   2  1  10.2   5.6
  6500  13.7  56.7  180  13  6   8.4   4.6 |  16.4  61.5  210   2  1  10.6   5.8
  6250  14.3  57.7  180  12  6   8.0   4.4 |  17.2  63.0  210   2  1  10.2   5.6
  6000  14.8  58.6  185  11  6   9.0   4.9 |  17.9  64.2  215   2  1  11.5   6.3
  5750  15.6  60.1  180  10  5  13.6   7.5 |  19.0  66.2  215   2  1  17.7   9.7
  5500  16.8  62.2  185   9  5  18.4  10.1 |  20.5  68.9  210   2  1  23.9  13.1

           07/31/2014 at 1500 MDT          |       07/31/2014 at 1800 MDT
                                           |
K index... +24.5  LI... -0.8               | K index... +21.9  LI... -1.2
CAPE... +60.9  CIN... -3.4                 | CAPE... +81.1  CIN... -7.2
                                           |
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 -61.6 -78.9  300  30 15   3.0   1.7 | -62.5 -80.5  300  36 19   3.7   1.6
 45000 -57.5 -71.5  295  53 28   1.9   1.0 | -58.3 -72.9  295  55 28   2.2   1.2
 40000 -53.5 -64.3  285  81 42   7.4   4.0 | -53.6 -64.5  285  76 39   7.9   4.3
 38000 -49.1 -56.4  290  72 37   7.4   4.1 | -48.9 -56.0  285  69 35   7.9   4.4
 36000 -44.6 -48.3  290  63 32   7.4   4.1 | -44.1 -47.4  285  61 32   7.9   4.3
 34000 -40.1 -40.2  290  52 27   7.7   4.2 | -39.6 -39.3  285  53 27   7.5   4.1
 32000 -35.5 -31.9  290  42 21   7.5   4.1 | -35.1 -31.2  290  44 23   7.3   4.0
 30000 -30.4 -22.7  295  36 19   8.5   4.7 | -30.4 -22.7  295  38 20   8.0   4.4
 29000 -27.2 -17.0  300  34 17   8.5   4.7 | -28.0 -18.4  295  35 18   8.0   4.4
 28000 -24.8 -12.6  300  32 16   7.0   3.9 | -25.1 -13.2  300  32 16   7.3   4.0
 27000 -22.7  -8.9  300  29 15   7.1   3.9 | -22.9  -9.2  305  28 14   7.3   4.0
 26000 -20.6  -5.1  305  27 14   7.1   3.9 | -20.7  -5.3  310  25 13   7.3   4.0
 25000 -18.4  -1.1  305  24 13   7.0   3.8 | -18.5  -1.3  315  21 11   7.2   3.9
 24000 -16.4   2.5  310  23 12   6.8   3.7 | -16.4   2.5  315  20 10   6.9   3.8
 23000 -14.4   6.1  310  22 11   6.8   3.7 | -14.4   6.1  315  18  9   7.0   3.8
 22000 -12.4   9.7  315  21 11   6.5   3.6 | -12.3   9.9  315  16  8   6.3   3.5
 21000 -10.7  12.7  315  18  9   6.1   3.4 | -10.7  12.7  315  14  7   5.6   3.1
 20000  -8.9  16.0  315  15  8   6.3   3.5 |  -9.2  15.4  320  12  6   5.7   3.1
 19500  -8.1  17.4  320  14  7   6.5   3.6 |  -8.4  16.9  320  11  6   5.8   3.2
 19000  -7.2  19.0  320  13  7   5.4   3.0 |  -7.5  18.5  325  10  5   5.6   3.1
 18500  -6.4  20.5  325  12  6   5.5   3.0 |  -6.6  20.1  325   9  5   5.7   3.1
 18000  -5.6  21.9  330  11  6   5.0   2.7 |  -5.7  21.7  330   8  4   5.2   2.9
 17500  -5.0  23.0  330  10  5   4.4   2.4 |  -5.1  22.8  340   7  4   4.7   2.6
 17000  -4.3  24.3  340  10  5   4.2   2.3 |  -4.4  24.1  350   6  3   4.5   2.5
 16500  -3.6  25.5  345   9  5   6.6   3.6 |  -3.6  25.5  360   5  3   6.7   3.6
 16000  -2.6  27.3  350   8  4   6.4   3.5 |  -2.6  27.3  010   5  3   6.5   3.5
 15500  -1.7  28.9  360   8  4   6.3   3.5 |  -1.7  28.9  020   5  3   6.6   3.6
 15000  -0.8  30.6  005   8  4   6.3   3.5 |  -0.7  30.7  030   5  3   6.7   3.7
 14500   0.6  33.1  010   7  4   6.6   3.6 |   0.2  32.4  045   5  3   6.7   3.7
 14000   1.5  34.7  020   6  3   6.7   3.6 |   1.6  34.9  060   5  3   6.7   3.7
 13500   2.5  36.5  025   6  3   6.5   3.5 |   2.6  36.7  070   6  3   6.7   3.7
 13000   3.4  38.1  035   5  3   6.4   3.5 |   3.5  38.3  085   6  3   6.7   3.7
 12500   4.3  39.7  045   4  2   6.3   3.4 |   4.4  39.9  090   6  3   6.6   3.6
 12000   5.2  41.4  070   4  2   6.2   3.4 |   5.3  41.5  095   6  3   6.6   3.6
 11500   6.1  43.0  095   4  2   6.2   3.4 |   6.2  43.2  090   5  3   7.3   4.0
 11000   7.0  44.6  100   4  2   6.1   3.4 |   7.3  45.1  085   5  2   7.6   4.2
 10500   7.8  46.0  100   4  2   2.8   1.5 |   8.3  46.9  080   4  2   2.7   1.5
 10250   7.9  46.2  095   4  2   5.1   2.8 |   8.4  47.1  080   4  2   5.5   3.0
 10000   8.6  47.5  095   3  2  11.8   6.5 |   9.3  48.7  080   4  2  13.9   7.6
  9750   9.4  48.9  090   3  2  11.1   6.1 |  10.2  50.4  080   4  2  12.3   6.8
  9500  10.1  50.2  085   3  1   8.6   4.7 |  11.0  51.8  075   4  2   9.2   5.1
  9250  10.6  51.1  080   3  1   6.5   3.6 |  11.5  52.7  075   3  2   6.7   3.7
  9000  11.2  52.2  080   3  1  10.8   5.9 |  12.2  54.0  075   3  2  10.4   5.7
  8750  12.1  53.8  080   3  1  12.6   6.9 |  13.0  55.4  075   3  1  11.6   6.3
  8500  12.9  55.2  075   2  1  10.1   5.5 |  13.8  56.8  075   2  1   9.7   5.3
  8250  13.6  56.5  075   2  1   9.1   5.0 |  14.5  58.1  070   2  1   8.9   4.9
  8000  14.3  57.7  075   2  1   9.8   5.4 |  15.1  59.2  070   2  1   9.7   5.3
  7750  15.1  59.2  075   2  1  10.3   5.6 |  15.9  60.6  070   2  1  10.2   5.6
  7500  15.8  60.4  070   2  1  10.2   5.6 |  16.6  61.9  065   2  1  10.0   5.5
  7250  16.6  61.9  070   2  1  10.3   5.6 |  17.4  63.3  065   1  1   9.7   5.3
  7000  17.3  63.1  070   2  1  10.1   5.5 |  18.1  64.6  060   1  1  10.7   5.9
  6750  18.1  64.6  070   2  1  10.1   5.5 |  18.9  66.0  060   1  0  10.6   5.8
  6500  18.8  65.8  065   2  1  10.3   5.7 |  19.6  67.3  050   1  0   9.6   5.3
  6250  19.6  67.3  065   1  1  10.1   5.5 |  20.3  68.5  035   1  0   9.7   5.3
  6000  20.3  68.5  060   1  1  10.9   6.0 |  21.1  70.0  020   1  0  10.3   5.6
  5750  21.3  70.3  050   1  1  15.6   8.5 |  21.9  71.4  005   1  0  12.5   6.8
  5500  22.6  72.7  050   1  1  20.9  11.4 |  22.9  73.2  360   1  0  14.3   7.8
________________________________________________________________________________

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.