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
000
UXUS97 KBOU 100022
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1821 MDT Wednesday, April 9, 2014

This forecast is for Thursday, April 10, 2014:

If the trigger temperature of 62.4 F/16.9 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 767 ft/min (3.9 m/s)
   Maximum height of thermals.................. 15096 ft MSL (9809 ft AGL)

Forecast maximum temperature................... 69.0 F/21.0 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 10139 ft MSL (4852 ft AGL)
Thermal soaring outlook for Friday 04/11....... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... Little change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 44914 ft MSL (39627 ft AGL)
Wave soaring outlook for Friday 04/11.......... Fair

Remarks...

Sunrise/Sunset.................... 06:29:28 / 19:31:43 MDT
Total possible sunshine........... 13 hr 2 min 16 sec (782 min 16 sec)
Altitude of sun at 13:00:45 MDT... 58.37 degrees

Upper air data from numerical model forecast valid on 04/10/2014 at 0600 MDT

Freezing level.................. 11436 ft MSL (6149 ft AGL)
Convective condensation level... 13932 ft MSL (8645 ft AGL)
Lifted condensation level....... 14261 ft MSL (8974 ft AGL)
Lifted index.................... -1.3
K index......................... +18.0

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  -60.3 -76.5   280   52   27   0.3   0.1      M     M       M      M    M
 45000  -59.9 -75.8   285   66   34  -0.4  -0.2      M     M       M      M    M
 40000  -61.2 -78.2   280   68   35  -0.9  -0.5      M     M       M      M    M
 38000  -59.7 -75.5   280   68   35   5.3   2.9      M     M       M      M    M
 36000  -56.6 -69.9   280   67   34   5.3   2.9      M     M       M      M    M
 34000  -53.2 -63.8   280   65   34   7.1   3.9      M     M       M      M    M
 32000  -49.0 -56.2   280   60   31   7.0   3.9      M     M       M      M    M
 30000  -43.9 -47.0   285   57   29   8.5   4.7   31.2  88.2     8.0      M    M
 29000  -41.4 -42.5   285   57   29   8.5   4.7   30.7  87.2     7.7      M    M
 28000  -38.8 -37.8   285   57   29   8.5   4.7   30.2  86.4     7.5      M    M
 27000  -36.3 -33.3   285   56   29   8.3   4.6   29.8  85.7     7.2      M    M
 26000  -33.8 -28.8   285   54   28   8.3   4.6   29.2  84.5     6.8      M    M
 25000  -31.3 -24.3   285   53   27   8.3   4.6   28.7  83.6     6.4      M    M
 24000  -28.8 -19.8   285   51   26   7.8   4.3   28.2  82.8     6.1      M    M
 23000  -26.6 -15.9   285   50   26   7.6   4.2   27.3  81.2     5.5      M    M
 22000  -24.3 -11.7   290   49   25   7.6   4.2   26.5  79.8     4.9      M    M
 21000  -22.1  -7.8   290   48   25   7.3   4.0   25.8  78.4     4.3      M    M
 20000  -19.9  -3.8   290   48   25   7.3   4.0   24.9  76.8     3.6      M    M
 19500  -18.7  -1.7   290   48   24   7.4   4.0   24.5  76.0     3.3      M    M
 19000  -17.6   0.3   290   47   24   7.4   4.1   24.1  75.4     3.0      M    M
 18500  -16.6   2.1   290   47   24   6.6   3.6   23.7  74.6     2.6      M    M
 18000  -15.6   3.9   290   47   24   6.6   3.6   23.1  73.6     2.1      M    M
 17500  -14.6   5.7   290   47   24   6.8   3.8   22.6  72.6     1.7      M    M
 17000  -13.6   7.5   290   46   24   7.6   4.2   22.1  71.9     1.3      M    M
 16500  -12.4   9.7   290   46   24   7.6   4.2   21.8  71.2     0.9      M    M
 16000  -11.3  11.7   290   45   23   8.1   4.5   21.5  70.6     0.6      M    M
 15500   -9.6  14.7   290   43   22   8.2   4.5   21.1  69.9     0.2      M    M
 15000   -8.4  16.9   290   41   21   8.3   4.6   20.8  69.4    -0.1    845  4.3
 14500   -7.1  19.2   295   38   20   8.3   4.6   20.6  69.0    -0.4    794  4.0
 14000   -5.9  21.4   295   36   18   8.4   4.6   20.3  68.6    -0.6    742  3.8
 13500   -4.7  23.5   295   33   17   8.4   4.6   20.1  68.2    -0.8    691  3.5
 13000   -3.5  25.7   295   30   16   7.9   4.3   19.9  67.7    -1.1    640  3.2
 12500   -2.3  27.9   300   27   14   7.8   4.3   19.5  67.2    -1.4    590  3.0
 12000   -1.2  29.8   300   25   13   7.9   4.3   19.2  66.6    -1.7    541  2.7
 11500   -0.0  32.0   300   22   12   7.9   4.3   18.9  66.1    -2.0    492  2.5
 11000    1.1  34.0   305   20   10   7.7   4.2   18.6  65.5    -2.3    442  2.2
 10500    2.3  36.1   305   19   10   8.4   4.6   18.3  64.9    -2.7    394  2.0
 10250    2.8  37.0   305   18    9   4.7   2.6   18.1  64.6    -2.9    369  1.9
 10000    3.1  37.6   305   17    9   5.7   3.1   17.6  63.7    -3.4    355  1.8
  9750    3.8  38.8   305   16    8  10.0   5.5   17.6  63.6    -3.4    327  1.7
  9500    4.4  39.9   305   15    8   9.4   5.1   17.5  63.6    -3.5    299  1.5
  9250    5.1  41.2   305   13    7   7.6   4.1   17.5  63.5    -3.5    272  1.4
  9000    5.5  41.9   310   12    6   5.7   3.1   17.2  63.0    -3.8    251  1.3
  8750    6.0  42.8   310   11    6   6.8   3.7   16.9  62.5    -4.1    230  1.2
  8500    6.5  43.7   315   10    5   7.0   3.8   16.7  62.1    -4.4    207  1.1
  8250    7.0  44.6   320    9    5   4.4   2.4   16.4  61.6    -4.6    186  0.9
  8000    7.1  44.8   330    9    4   1.8   1.0   15.9  60.6    -5.2    174  0.9
  7750    7.2  45.0   340    8    4   1.3   0.7   15.3  59.5    -5.9    163  0.8
  7500    7.3  45.1   355    7    4   0.2   0.1   14.6  58.2    -6.6    155  0.8
  7250    7.2  45.0   015    7    4  -0.4  -0.2   13.8  56.9    -7.4    149  0.8
  7000    7.2  45.0   040    9    5  -0.7  -0.4   13.0  55.5    -8.2    144  0.7
  6750    7.1  44.8   055   11    6  -0.8  -0.5   12.2  54.0    -9.0    139  0.7
  6500    7.0  44.6   060   13    7  -1.2  -0.7   11.4  52.5    -9.9    134  0.7
  6250    6.9  44.4   050   11    6  -2.1  -1.2   10.6  51.0   -10.7    130  0.7
  6000    6.8  44.2   035   10    5   0.4   0.2    9.7  49.5   -11.6    126  0.6
  5750    6.8  44.2   020   10    5  -3.8  -2.1    9.0  48.2   -12.3    117  0.6
  5500    5.8  42.4   360    6    3 -22.8 -12.5    7.3  45.2   -14.0    139  0.7

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

           04/10/2014 at 0900 MDT          |       04/10/2014 at 1200 MDT
                                           |
K index... +15.1  LI... +1.2               | K index... +12.5  LI... +0.6
CAPE... 0.0  CIN... -0.4                   | CAPE... +0.9  CIN... -1.8
                                           |
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 -60.7 -77.3  290  47 24   0.6   0.3 | -61.8 -79.2  290  41 21   1.0   0.6
 45000 -59.8 -75.6  290  61 31  -0.2  -0.1 | -60.2 -76.4  290  60 31   0.0   0.0
 40000 -60.6 -77.1  285  60 31  -0.5  -0.3 | -60.7 -77.3  290  59 31  -0.3  -0.2
 38000 -59.3 -74.7  285  60 31   4.2   2.3 | -59.5 -75.1  290  56 29   3.8   2.1
 36000 -56.8 -70.2  285  60 31   4.2   2.3 | -57.2 -71.0  290  51 26   3.8   2.1
 34000 -53.9 -65.0  285  59 30   7.3   4.0 | -54.3 -65.7  290  46 24   8.1   4.5
 32000 -49.5 -57.1  285  56 29   7.2   4.0 | -49.4 -56.9  290  43 22   8.2   4.5
 30000 -44.4 -47.9  285  52 27   8.4   4.6 | -43.8 -46.8  285  40 21   8.4   4.6
 29000 -41.9 -43.4  285  51 26   8.4   4.6 | -41.3 -42.3  290  39 20   8.4   4.6
 28000 -39.3 -38.7  285  50 26   8.4   4.6 | -38.8 -37.8  290  38 20   8.4   4.6
 27000 -36.8 -34.2  290  49 25   8.3   4.5 | -36.3 -33.3  290  38 20   8.0   4.4
 26000 -34.3 -29.7  290  48 25   8.3   4.6 | -33.9 -29.0  290  39 20   8.1   4.4
 25000 -31.9 -25.4  290  48 25   8.3   4.6 | -31.5 -24.7  290  39 20   8.1   4.4
 24000 -29.4 -20.9  290  47 24   8.2   4.5 | -29.1 -20.4  290  40 20   7.9   4.4
 23000 -26.9 -16.4  295  48 25   8.2   4.5 | -26.7 -16.1  295  40 21   7.9   4.4
 22000 -24.5 -12.1  295  48 25   8.2   4.5 | -24.4 -11.9  295  41 21   7.9   4.4
 21000 -22.1  -7.8  295  48 25   7.1   3.9 | -22.0  -7.6  295  42 21   7.3   4.0
 20000 -20.0  -4.0  295  48 25   7.2   3.9 | -19.8  -3.6  295  42 22   7.4   4.1
 19500 -18.9  -2.0  295  48 25   7.2   3.9 | -18.7  -1.7  295  42 22   7.4   4.1
 19000 -17.8  -0.0  295  48 25   7.2   4.0 | -17.6   0.3  295  42 22   7.4   4.1
 18500 -16.8   1.8  295  48 25   7.0   3.8 | -16.5   2.3  295  43 22   7.1   3.9
 18000 -15.7   3.7  295  48 25   7.0   3.8 | -15.5   4.1  295  43 22   7.1   3.9
 17500 -14.7   5.5  295  48 25   7.2   4.0 | -14.4   6.1  295  43 22   7.3   4.0
 17000 -13.6   7.5  290  47 24   7.7   4.2 | -13.3   8.1  290  43 22   7.7   4.2
 16500 -12.4   9.7  290  47 24   7.8   4.3 | -12.1  10.2  290  43 22   7.7   4.2
 16000 -11.3  11.7  290  46 24   8.1   4.4 | -10.9  12.4  290  43 22   8.5   4.7
 15500 -10.1  13.8  290  45 23   8.2   4.5 |  -9.7  14.5  285  42 22   8.5   4.7
 15000  -8.4  16.9  290  43 22   7.7   4.2 |  -7.9  17.8  285  41 21   8.0   4.4
 14500  -7.3  18.9  290  41 21   7.8   4.3 |  -6.8  19.8  280  40 20   8.1   4.5
 14000  -6.1  21.0  290  38 20   8.3   4.5 |  -5.6  21.9  280  38 19   7.7   4.2
 13500  -4.9  23.2  290  36 18   8.3   4.5 |  -4.5  23.9  280  35 18   7.8   4.3
 13000  -3.7  25.3  290  33 17   7.6   4.2 |  -3.4  25.9  280  32 17   7.5   4.1
 12500  -2.6  27.3  295  30 16   7.6   4.2 |  -2.3  27.9  280  29 15   7.5   4.1
 12000  -1.5  29.3  295  28 14   8.0   4.4 |  -1.2  29.8  275  27 14   7.9   4.3
 11500  -0.3  31.5  300  26 13   8.1   4.5 |  -0.0  32.0  275  23 12   7.9   4.3
 11000   0.8  33.4  300  24 12   6.6   3.6 |   1.1  34.0  275  21 11   8.3   4.5
 10500   1.8  35.2  300  21 11   7.3   4.0 |   2.4  36.3  270  18 10   9.1   5.0
 10250   2.2  36.0  300  20 10   3.3   1.8 |   3.0  37.4  270  17  9   4.9   2.7
 10000   2.4  36.3  300  19 10   4.2   2.3 |   3.2  37.8  270  17  9   5.7   3.1
  9750   2.9  37.2  300  18  9   8.6   4.7 |   3.9  39.0  265  15  8  10.3   5.6
  9500   3.5  38.3  300  17  9   8.4   4.6 |   4.6  40.3  265  14  7   9.7   5.3
  9250   4.1  39.4  295  15  8   5.0   2.7 |   5.3  41.5  260  13  7   7.5   4.1
  9000   4.3  39.7  295  14  7   2.2   1.2 |   5.7  42.3  260  12  6   5.9   3.2
  8750   4.5  40.1  295  12  6   4.5   2.5 |   6.2  43.2  255  11  6   7.5   4.1
  8500   4.8  40.6  290  11  6   4.1   2.3 |   6.8  44.2  250  11  6   7.0   3.8
  8250   5.1  41.2  290   9  5   1.9   1.0 |   7.3  45.1  250  10  5   5.6   3.1
  8000   5.1  41.2  290   8  4   0.4   0.2 |   7.6  45.7  245   9  4   4.5   2.5
  7750   5.1  41.2  285   6  3  -0.7  -0.4 |   7.9  46.2  235   7  4   4.2   2.3
  7500   5.0  41.0  280   4  2   0.4   0.2 |   8.2  46.8  230   6  3   4.5   2.5
  7250   5.1  41.2  235   2  1   3.2   1.8 |   8.6  47.5  215   5  2   5.5   3.0
  7000   5.3  41.5  150   3  2   3.4   1.9 |   8.9  48.0  200   4  2   5.8   3.2
  6750   5.5  41.9  135   6  3   2.0   1.1 |   9.3  48.7  185   4  2   7.3   4.0
  6500   5.7  42.3  130   8  4   3.7   2.1 |   9.9  49.8  185   3  2  10.1   5.5
  6250   6.1  43.0  130   7  4   6.6   3.6 |  10.8  51.4  185   3  2  11.6   6.4
  6000   6.5  43.7  125   5  3   4.3   2.4 |  11.6  52.9  185   3  2   9.9   5.4
  5750   6.9  44.4  120   4  2   8.7   4.8 |  12.4  54.3  185   3  2  13.7   7.5
  5500   8.0  46.4  120   4  2  20.5  11.2 |  13.8  56.8  180   3  1  25.5  14.0

           04/10/2014 at 1500 MDT          |       04/10/2014 at 1800 MDT
                                           |
K index... +14.0  LI... -1.8               | K index... +17.8  LI... -1.7
CAPE... +162.5  CIN... -21.9               | CAPE... +120.9  CIN... -19.8
                                           |
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 -61.0 -77.8  290  41 21   0.7   0.4 | -60.7 -77.3  290  48 24   0.2   0.1
 45000 -60.0 -76.0  295  58 30   0.0   0.0 | -60.3 -76.5  295  59 30  -0.2  -0.1
 40000 -60.3 -76.5  290  59 31  -0.2  -0.1 | -60.8 -77.4  290  60 31  -0.3  -0.2
 38000 -59.1 -74.4  285  57 30   3.8   2.1 | -59.4 -74.9  290  58 30   4.2   2.3
 36000 -56.8 -70.2  290  54 28   3.8   2.1 | -56.8 -70.2  290  54 28   4.2   2.3
 34000 -53.9 -65.0  290  50 26   8.1   4.4 | -53.8 -64.8  285  51 26   7.9   4.4
 32000 -49.0 -56.2  285  48 25   8.1   4.5 | -49.0 -56.2  290  50 26   8.0   4.4
 30000 -43.5 -46.3  285  45 23   8.6   4.7 | -43.3 -45.9  290  48 25   9.0   4.9
 29000 -40.9 -41.6  290  44 23   8.6   4.7 | -40.6 -41.1  290  46 24   9.0   4.9
 28000 -38.3 -36.9  290  42 22   8.6   4.7 | -38.0 -36.4  290  45 23   9.0   4.9
 27000 -35.8 -32.4  290  41 21   7.6   4.2 | -35.4 -31.7  290  44 22   7.5   4.1
 26000 -33.5 -28.3  290  41 21   7.7   4.2 | -33.1 -27.6  290  43 22   7.7   4.2
 25000 -31.2 -24.2  290  41 21   7.7   4.2 | -30.8 -23.4  290  41 21   7.7   4.2
 24000 -28.9 -20.0  290  41 21   7.5   4.1 | -28.5 -19.3  290  41 21   7.3   4.0
 23000 -26.7 -16.1  290  41 21   7.4   4.1 | -26.3 -15.3  290  41 21   7.2   4.0
 22000 -24.4 -11.9  290  42 21   7.5   4.1 | -24.2 -11.6  290  42 21   7.2   4.0
 21000 -22.3  -8.1  290  42 22   7.1   3.9 | -22.0  -7.6  290  42 22   6.8   3.7
 20000 -20.1  -4.2  290  42 22   7.1   3.9 | -20.0  -4.0  295  43 22   6.8   3.8
 19500 -19.0  -2.2  290  42 21   7.1   3.9 | -19.0  -2.2  295  43 22   6.8   3.8
 19000 -18.0  -0.4  290  42 21   7.1   3.9 | -18.0  -0.4  295  44 22   6.8   3.7
 18500 -16.9   1.6  290  42 21   7.8   4.3 | -16.9   1.6  295  44 23   7.3   4.0
 18000 -15.7   3.7  290  42 22   7.8   4.3 | -15.8   3.6  295  44 23   7.4   4.1
 17500 -14.5   5.9  290  42 22   7.9   4.3 | -14.7   5.5  295  45 23   7.7   4.2
 17000 -13.4   7.9  285  42 21   7.9   4.3 | -13.5   7.7  295  44 23   8.3   4.6
 16500 -12.2  10.0  285  41 21   7.8   4.3 | -12.3   9.9  290  44 22   8.3   4.6
 16000 -11.0  12.2  285  40 21   8.9   4.9 | -11.0  12.2  290  42 22   9.0   4.9
 15500  -9.7  14.5  285  39 20   8.8   4.9 |  -9.7  14.5  290  41 21   9.0   4.9
 15000  -7.7  18.1  285  37 19   8.5   4.7 |  -7.8  18.0  290  38 20   8.7   4.8
 14500  -6.5  20.3  280  35 18   8.6   4.7 |  -6.5  20.3  285  36 18   8.8   4.8
 14000  -5.3  22.5  280  33 17   8.3   4.6 |  -5.2  22.6  285  34 17   8.9   4.9
 13500  -4.0  24.8  275  31 16   8.4   4.6 |  -3.9  25.0  285  31 16   9.0   4.9
 13000  -2.8  27.0  275  28 15   8.5   4.6 |  -2.6  27.3  285  29 15   8.7   4.8
 12500  -1.6  29.1  270  26 13   8.4   4.6 |  -1.4  29.5  280  26 13   8.7   4.8
 12000  -0.3  31.5  270  23 12   9.0   4.9 |  -0.1  31.8  280  23 12   9.0   4.9
 11500   1.0  33.8  265  21 11   9.0   4.9 |   1.2  34.2  280  21 11   9.1   5.0
 11000   2.3  36.1  265  18  9   9.1   5.0 |   2.5  36.5  280  19 10   7.9   4.3
 10500   3.6  38.5  260  16  8  10.0   5.5 |   3.7  38.7  275  17  9   7.0   3.8
 10250   4.3  39.7  260  15  8   5.6   3.1 |   4.3  39.7  275  16  8  11.2   6.2
 10000   4.5  40.1  260  14  7   6.2   3.4 |   5.3  41.5  275  14  7  12.1   6.7
  9750   5.3  41.5  255  13  7  11.0   6.0 |   5.9  42.6  275  13  7   8.6   4.7
  9500   6.0  42.8  250  11  6  10.1   5.5 |   6.6  43.9  275  12  6   9.5   5.2
  9250   6.7  44.1  245  10  5   8.9   4.9 |   7.3  45.1  275  11  6   9.3   5.1
  9000   7.3  45.1  245   9  5   8.1   4.4 |   8.0  46.4  275  11  5   9.9   5.4
  8750   8.0  46.4  240   8  4   9.2   5.1 |   8.8  47.8  275  10  5  10.3   5.6
  8500   8.6  47.5  240   7  3   8.9   4.9 |   9.5  49.1  275  10  5  10.2   5.6
  8250   9.3  48.7  235   6  3  10.1   5.5 |  10.3  50.5  275   9  5  10.2   5.6
  8000  10.0  50.0  235   5  3  10.4   5.7 |  11.0  51.8  275   9  5   9.9   5.4
  7750  10.8  51.4  240   5  3   9.6   5.3 |  11.7  53.1  275   9  5   9.4   5.2
  7500  11.5  52.7  240   5  3   9.8   5.4 |  12.5  54.5  275   9  5   9.5   5.2
  7250  12.2  54.0  240   5  3  10.1   5.5 |  13.2  55.8  275   9  4   9.7   5.3
  7000  13.0  55.4  240   5  3  10.2   5.6 |  13.9  57.0  275   9  4   9.9   5.4
  6750  13.7  56.7  240   5  2   9.6   5.3 |  14.6  58.3  280   8  4   9.9   5.4
  6500  14.5  58.1  245   5  2  10.1   5.5 |  15.4  59.7  280   8  4  10.1   5.6
  6250  15.3  59.5  245   5  2  11.2   6.1 |  16.1  61.0  280   8  4  10.4   5.7
  6000  16.1  61.0  245   4  2  10.1   5.5 |  16.9  62.4  280   8  4  10.2   5.6
  5750  16.9  62.4  245   4  2  12.6   6.9 |  17.7  63.9  280   8  4  10.6   5.8
  5500  18.1  64.6  250   4  2  21.8  12.0 |  18.5  65.3  280   7  4  12.9   7.1
________________________________________________________________________________

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.