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
000
UXUS97 KBOU 280122
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1822 MST Sunday, November 27, 2016

This forecast is for Monday, November 28, 2016:

If the trigger temperature of 40.7 F/4.8 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 18 ft/min (0.1 m/s)
   Maximum height of thermals.................. 11047 ft MSL (5740 ft AGL)

Forecast maximum temperature................... 45.0 F/7.7 C
Time of trigger temperature.................... 1100 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8779 ft MSL (3472 ft AGL)
Thermal soaring outlook for Tuesday 11/29...... Poor

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1700 MST)................ Neither
Potential height of wave....................... 14388 ft MSL (9081 ft AGL)
Wave soaring outlook for Tuesday 11/29......... Fair

Remarks...

Sunrise/Sunset.................... 06:59:13 / 16:36:10 MST
Total possible sunshine........... 9 hr 36 min 58 sec (576 min 58 sec)
Altitude of sun at 11:47:42 MST... 28.69 degrees

Upper air data from numerical model forecast valid on 11/28/2016 at 0500 MST

Freezing level.................. 6003 ft MSL (696 ft AGL)
Convective condensation level... 13886 ft MSL (8579 ft AGL)
Lifted condensation level....... 13191 ft MSL (7885 ft AGL)
Lifted index.................... +1.7
K index......................... +8.7

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  -52.4 -62.3   265   16    8   1.6   0.9      M     M       M      M    M
 45000  -50.0 -58.0   270   17    9   1.6   0.9      M     M       M      M    M
 40000  -47.7 -53.9   280   17    8   1.4   0.8      M     M       M      M    M
 38000  -46.9 -52.4   280   16    8   1.1   0.6      M     M       M      M    M
 36000  -47.0 -52.6   285   15    8  -0.4  -0.2      M     M       M      M    M
 34000  -47.3 -53.1   290   14    7  -0.4  -0.2      M     M       M      M    M
 32000  -48.5 -55.3   300   13    7  -4.1  -2.2      M     M       M      M    M
 30000  -51.0 -59.8   315   13    7  -4.1  -2.2      M     M       M      M    M
 29000  -52.2 -62.0   320   13    7  -0.6  -0.3      M     M       M      M    M
 28000  -50.5 -58.9   320   12    6   4.9   2.7   18.5  65.4     8.6      M    M
 27000  -49.0 -56.2   325   12    6   4.9   2.7   16.6  62.0     7.3      M    M
 26000  -47.5 -53.5   325   11    6   5.5   3.0   14.9  58.9     6.0      M    M
 25000  -45.1 -49.2   320   10    5   8.9   4.9   14.3  57.7     5.6      M    M
 24000  -42.4 -44.3   315    9    5   8.9   4.9   14.0  57.1     5.4      M    M
 23000  -39.7 -39.5   310    9    5   8.8   4.9   13.7  56.7     5.3      M    M
 22000  -37.2 -35.0   300    8    4   8.5   4.6   13.2  55.8     4.9      M    M
 21000  -34.7 -30.5   295    8    4   8.5   4.6   12.8  55.0     4.6      M    M
 20000  -32.1 -25.8   290    8    4   8.7   4.8   12.4  54.3     4.3      M    M
 19500  -30.8 -23.4   290    7    4   8.8   4.8   12.2  53.9     4.2      M    M
 19000  -29.5 -21.1   290    7    4   8.8   4.8   12.0  53.6     4.0      M    M
 18500  -28.2 -18.8   290    7    4   8.8   4.8   11.8  53.3     3.9      M    M
 18000  -26.9 -16.4   290    7    4   8.8   4.8   11.7  53.0     3.8      M    M
 17500  -25.6 -14.1   290    7    4   8.3   4.5   11.5  52.7     3.7      M    M
 17000  -24.4 -11.9   295    7    4   8.1   4.5   11.2  52.2     3.4      M    M
 16500  -23.2  -9.8   300    7    4   8.1   4.4   11.0  51.7     3.2      M    M
 16000  -22.0  -7.6   305    8    4   7.9   4.3   10.6  51.1     2.9      M    M
 15500  -20.8  -5.4   310    8    4   7.9   4.3   10.3  50.6     2.7      M    M
 15000  -19.1  -2.4   320    9    5   8.1   4.5    9.9  49.8     2.3      M    M
 14500  -17.8  -0.0   325   10    5   8.2   4.5    9.6  49.4     2.1      M    M
 14000  -16.6   2.1   325   11    6   8.5   4.6    9.4  48.9     1.9      M    M
 13500  -15.3   4.5   325   12    6   8.4   4.6    9.2  48.6     1.7      M    M
 13000  -14.1   6.6   325   13    7   8.3   4.5    9.0  48.2     1.5      M    M
 12500  -12.9   8.8   325   14    7   8.2   4.5    8.7  47.7     1.3      M    M
 12000  -11.8  10.8   325   15    8   6.6   3.6    8.3  47.0     0.9      M    M
 11500  -10.8  12.6   320   16    8   6.7   3.7    7.9  46.1     0.4      M    M
 11000   -9.9  14.2   315   17    9   6.0   3.3    7.3  45.2    -0.1    410  2.1
 10500   -9.0  15.8   315   17    9   6.0   3.3    6.7  44.1    -0.7    369  1.9
 10250   -8.5  16.7   310   18    9   6.1   3.3    6.4  43.6    -1.0    348  1.8
 10000   -8.1  17.4   310   18    9   5.3   2.9    6.1  43.0    -1.3    328  1.7
  9750   -7.7  18.1   310   18    9   4.6   2.5    5.7  42.3    -1.7    310  1.6
  9500   -7.4  18.7   305   18    9   5.1   2.8    5.3  41.6    -2.0    293  1.5
  9250   -7.0  19.4   305   18    9   5.7   3.1    5.0  41.0    -2.4    274  1.4
  9000   -6.6  20.1   305   18    9   5.8   3.2    4.7  40.5    -2.7    253  1.3
  8750   -6.2  20.8   305   17    9   4.6   2.5    4.4  39.8    -3.1    234  1.2
  8500   -5.8  21.6   300   16    8   6.4   3.5    4.0  39.1    -3.4    217  1.1
  8250   -5.2  22.6   300   15    8   8.7   4.8    3.8  38.9    -3.6    191  1.0
  8000   -4.6  23.7   300   14    7   8.2   4.5    3.7  38.7    -3.7    165  0.8
  7750   -4.0  24.8   300   14    7   6.6   3.6    3.6  38.5    -3.9    141  0.7
  7500   -3.6  25.5   300   13    7   7.3   4.0    3.3  38.0    -4.1    119  0.6
  7250   -2.9  26.8   300   12    6   8.9   4.9    3.2  37.8    -4.2     92  0.5
  7000   -2.3  27.9   300   11    6   8.6   4.7    3.1  37.7    -4.3     66  0.3
  6750   -1.7  28.9   300   10    5   7.6   4.2    3.0  37.5    -4.4     40  0.2
  6500   -1.2  29.8   300    9    5   6.9   3.8    2.8  37.1    -4.7     17  0.1
  6250   -0.6  30.9   295    8    4   7.8   4.3    2.6  36.8    -4.9      M    M
  6000   -0.1  31.8   295    7    4   6.2   3.4    2.5  36.5    -5.0      M    M
  5750    0.3  32.5   290    6    3   2.7   1.5    2.1  35.7    -5.5      M    M
  5500    0.4  32.7   280    4    2   1.2   0.7    1.5  34.6    -6.1      M    M

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

           11/28/2016 at 0800 MST          |       11/28/2016 at 1100 MST
                                           |
CAPE...     0.0    LI...       +2.8        | CAPE...     0.0    LI...       +2.6
CINH...     0.0    K Index...  +2.0        | CINH...    -1.0    K Index...  +0.7
                                           |
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 -51.8 -61.2  275  17  9   1.6   0.9 | -52.9 -63.2  290  16  8   1.8   1.0
 45000 -49.5 -57.1  285  18  9   1.6   0.9 | -50.3 -58.5  295  21 11   1.8   1.0
 40000 -47.5 -53.5  285  17  9   1.2   0.7 | -47.1 -52.8  295  20 10   2.1   1.2
 38000 -46.8 -52.2  290  17  9   1.5   0.8 | -45.8 -50.4  295  19 10   1.6   0.9
 36000 -47.4 -53.3  295  17  9  -1.3  -0.7 | -45.9 -50.6  290  20 10  -0.3  -0.2
 34000 -48.1 -54.6  300  16  8  -1.3  -0.7 | -46.1 -51.0  290  20 10  -0.3  -0.2
 32000 -49.3 -56.7  300  17  9  -2.6  -1.4 | -47.6 -53.7  290  20 10  -5.0  -2.7
 30000 -50.9 -59.6  305  17  9  -2.6  -1.4 | -50.6 -59.1  285  20 10  -5.0  -2.7
 29000 -51.5 -60.7  305  17  9   2.6   1.4 | -52.1 -61.8  285  19 10  -1.3  -0.7
 28000 -50.1 -58.2  300  16  8   4.6   2.5 | -49.9 -57.8  285  19 10   6.4   3.5
 27000 -48.7 -55.7  295  14  7   4.6   2.5 | -48.0 -54.4  285  19 10   6.4   3.5
 26000 -47.4 -53.3  285  13  6   4.1   2.3 | -46.1 -51.0  285  19 10   6.4   3.5
 25000 -45.2 -49.4  285  11  6   8.3   4.5 | -44.1 -47.4  280  17  9   6.8   3.8
 24000 -42.7 -44.9  280  11  5   8.3   4.5 | -42.1 -43.8  270  15  8   6.8   3.8
 23000 -40.2 -40.4  280  10  5   8.3   4.5 | -40.0 -40.0  260  14  7   6.8   3.8
 22000 -37.7 -35.9  280   9  5   8.3   4.5 | -37.7 -35.9  255  13  7   8.0   4.4
 21000 -35.3 -31.5  280   8  4   8.3   4.5 | -35.4 -31.7  245  12  6   7.9   4.4
 20000 -32.8 -27.0  280   8  4   8.6   4.7 | -33.0 -27.4  240  11  5   8.5   4.7
 19500 -31.5 -24.7  280   8  4   8.8   4.8 | -31.7 -25.1  240  10  5   8.7   4.8
 19000 -30.1 -22.2  285   8  4   8.8   4.8 | -30.4 -22.7  240   9  5   8.7   4.8
 18500 -28.8 -19.8  290   8  4   8.8   4.8 | -29.1 -20.4  240   9  5   8.7   4.8
 18000 -27.5 -17.5  290   7  4   8.8   4.8 | -27.8 -18.0  240   8  4   8.7   4.8
 17500 -25.5 -13.9  300   7  4   8.9   4.9 | -26.4 -15.5  240   8  4   8.8   4.8
 17000 -24.2 -11.6  305   7  4   8.8   4.9 | -25.1 -13.2  245   7  4   8.8   4.8
 16500 -22.8  -9.0  310   8  4   8.9   4.9 | -23.8 -10.8  245   7  3   8.9   4.9
 16000 -21.5  -6.7  315   8  4   9.0   4.9 | -22.5  -8.5  250   6  3   9.1   5.0
 15500 -20.1  -4.2  320   8  4   8.7   4.8 | -21.1  -6.0  255   6  3   9.1   5.0
 15000 -18.9  -2.0  320   9  5   8.3   4.6 | -19.8  -3.6  265   6  3   8.9   4.9
 14500 -17.6   0.3  325  10  5   8.3   4.6 | -17.8  -0.0  275   7  4   8.8   4.8
 14000 -16.4   2.5  325  10  5   8.2   4.5 | -16.5   2.3  280   8  4   8.4   4.6
 13500 -15.2   4.6  325  11  6   8.2   4.5 | -15.3   4.5  285   9  5   8.4   4.6
 13000 -14.0   6.8  320  12  6   7.7   4.2 | -14.1   6.6  285  10  5   7.8   4.3
 12500 -12.8   9.0  320  12  6   7.8   4.3 | -12.9   8.8  285  12  6   7.9   4.3
 12000 -11.7  10.9  315  13  7   6.8   3.7 | -11.9  10.6  285  13  7   5.9   3.2
 11500 -10.7  12.7  310  15  7   7.0   3.8 | -11.0  12.2  285  14  7   6.1   3.4
 11000  -9.8  14.4  310  16  8   5.5   3.0 | -10.2  13.6  285  15  8   4.6   2.5
 10500  -9.0  15.8  305  17  9   5.6   3.1 |  -9.5  14.9  285  16  8   4.7   2.6
 10250  -8.6  16.5  300  18  9   5.0   2.8 |  -9.2  15.4  285  16  8   5.8   3.2
 10000  -8.3  17.1  300  18  9   4.3   2.3 |  -8.7  16.3  285  16  8   5.6   3.1
  9750  -8.0  17.6  300  18  9   4.0   2.2 |  -8.4  16.9  285  15  8   4.4   2.4
  9500  -7.7  18.1  295  18  9   4.1   2.2 |  -8.1  17.4  285  14  7   5.3   2.9
  9250  -7.4  18.7  295  18  9   4.2   2.3 |  -7.6  18.3  285  13  7   6.8   3.7
  9000  -7.1  19.2  295  18  9   4.7   2.6 |  -7.1  19.2  285  12  6   7.9   4.3
  8750  -6.7  19.9  295  17  9   5.3   2.9 |  -6.5  20.3  285  11  6   8.3   4.5
  8500  -6.3  20.7  295  16  8   6.9   3.8 |  -5.8  21.6  285  10  5   8.9   4.9
  8250  -5.7  21.7  295  15  8   8.1   4.5 |  -5.1  22.8  285   9  5   9.5   5.2
  8000  -5.1  22.8  295  14  7   8.1   4.4 |  -4.4  24.1  285   8  4   9.3   5.1
  7750  -4.5  23.9  295  13  7   8.1   4.5 |  -3.8  25.2  285   7  4   8.3   4.6
  7500  -3.9  25.0  295  12  6   8.0   4.4 |  -3.2  26.2  285   6  3   9.1   5.0
  7250  -3.3  26.1  295  11  6   7.9   4.3 |  -2.4  27.7  285   6  3  10.3   5.7
  7000  -2.7  27.1  295  10  5   7.9   4.3 |  -1.7  28.9  285   6  3   9.9   5.4
  6750  -2.1  28.2  295   9  5   8.0   4.4 |  -0.9  30.4  285   5  3   9.5   5.2
  6500  -1.5  29.3  290   8  4   7.7   4.2 |  -0.2  31.6  285   5  3   9.7   5.3
  6250  -1.0  30.2  290   7  4   7.6   4.2 |   0.5  32.9  285   5  2  10.5   5.8
  6000  -0.4  31.3  285   6  3   7.0   3.8 |   1.3  34.3  285   5  2   9.4   5.1
  5750   0.0  32.0  280   5  3   4.0   2.2 |   2.0  35.6  285   4  2  12.9   7.1
  5500   0.2  32.4  265   3  2   1.1   0.6 |   3.3  37.9  285   4  2  21.7  11.9

           11/28/2016 at 1400 MST          |       11/28/2016 at 1700 MST
                                           |
CAPE...     0.0    LI...       +2.3        | CAPE...     0.0    LI...       +2.1
CINH...    -0.6    K Index... +10.7        | CINH...    -0.5    K Index... +13.2
                                           |
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 -53.1 -63.6  290  18  9   2.0   1.1 | -53.4 -64.1  295  21 11   2.6   1.4
 45000 -50.1 -58.2  295  23 12   2.0   1.1 | -49.5 -57.1  290  24 12   2.6   1.4
 40000 -45.5 -49.9  295  21 11   3.1   1.7 | -45.1 -49.2  290  20 10   2.8   1.6
 38000 -43.7 -46.7  290  20 10   2.5   1.4 | -43.4 -46.1  290  18  9   2.3   1.2
 36000 -43.9 -47.0  290  21 11  -0.6  -0.3 | -43.4 -46.1  285  19 10  -0.1  -0.0
 34000 -44.3 -47.7  285  22 12  -0.6  -0.3 | -43.4 -46.1  285  20 10  -0.1  -0.0
 32000 -45.8 -50.4  280  23 12  -5.5  -3.0 | -44.6 -48.3  285  19 10  -4.8  -2.6
 30000 -49.1 -56.4  275  21 11  -5.4  -3.0 | -47.4 -53.3  275  18  9  -4.7  -2.6
 29000 -50.9 -59.6  270  20 10   1.8   1.0 | -49.1 -56.4  270  17  9  -0.9  -0.5
 28000 -49.5 -57.1  265  19 10   4.5   2.5 | -48.8 -55.8  265  15  8   1.2   0.6
 27000 -48.2 -54.8  260  18  9   4.5   2.5 | -48.4 -55.1  255  14  7   1.2   0.6
 26000 -46.8 -52.2  255  17  9   4.1   2.3 | -48.1 -54.6  250  12  6   0.4   0.2
 25000 -44.7 -48.5  250  16  8   8.3   4.5 | -46.1 -51.0  250  12  6   8.9   4.9
 24000 -42.2 -44.0  245  15  8   8.3   4.5 | -43.4 -46.1  260  11  6   8.9   4.9
 23000 -39.7 -39.5  235  15  8   8.4   4.6 | -40.8 -41.4  265  11  6   9.0   4.9
 22000 -37.6 -35.7  230  14  7   6.9   3.8 | -38.2 -36.8  270  11  6   8.3   4.6
 21000 -35.5 -31.9  220  13  7   6.9   3.8 | -35.7 -32.3  275  11  5   8.3   4.6
 20000 -33.5 -28.3  210  12  6   7.4   4.0 | -33.3 -27.9  280  10  5   7.8   4.3
 19500 -32.3 -26.1  210  11  6   7.9   4.3 | -32.2 -26.0  280  10  5   7.1   3.9
 19000 -31.1 -24.0  215  10  5   7.9   4.3 | -31.1 -24.0  285  10  5   7.1   3.9
 18500 -29.9 -21.8  215   9  5   7.9   4.3 | -30.1 -22.2  290  10  5   7.1   3.9
 18000 -28.7 -19.7  215   9  4   8.0   4.4 | -29.0 -20.2  290  10  5   7.1   3.9
 17500 -27.6 -17.7  215   8  4   8.3   4.6 | -27.9 -18.2  295  10  5   7.1   3.9
 17000 -26.3 -15.3  230   7  4   8.7   4.8 | -26.9 -16.4  300  10  5   7.0   3.9
 16500 -25.0 -13.0  245   7  4   8.8   4.8 | -25.9 -14.6  300  11  6   7.0   3.9
 16000 -23.7 -10.7  265   8  4   7.8   4.3 | -24.8 -12.6  305  12  6   7.2   3.9
 15500 -22.0  -7.6  280  11  6   7.6   4.2 | -23.7 -10.7  310  12  6   7.2   3.9
 15000 -20.9  -5.6  280  13  7   7.0   3.8 | -22.7  -8.9  310  13  7   7.3   4.0
 14500 -19.9  -3.8  285  15  8   7.0   3.9 | -21.0  -5.8  315  13  7   7.4   4.1
 14000 -18.8  -1.8  285  16  8   7.3   4.0 | -19.9  -3.8  315  13  7   7.9   4.3
 13500 -17.7   0.1  285  18  9   7.3   4.0 | -18.7  -1.7  315  13  7   7.9   4.3
 13000 -16.7   1.9  285  18  9   7.2   3.9 | -17.6   0.3  315  13  7   7.4   4.0
 12500 -15.6   3.9  285  19 10   7.1   3.9 | -16.5   2.3  310  13  7   7.3   4.0
 12000 -14.5   5.9  285  18  9   7.7   4.2 | -15.4   4.3  310  13  6   8.0   4.4
 11500 -13.4   7.9  285  17  9   7.6   4.2 | -14.2   6.4  305  12  6   7.9   4.3
 11000 -12.2  10.0  285  15  8   8.0   4.4 | -12.9   8.8  300  12  6   8.8   4.8
 10500 -11.0  12.2  285  14  7   7.7   4.2 | -11.6  11.1  300  12  6   8.7   4.8
 10250 -10.4  13.3  280  13  7  10.5   5.8 | -11.0  12.2  295  12  6  10.1   5.5
 10000  -9.5  14.9  280  12  6  10.2   5.6 | -10.2  13.6  295  11  6   9.5   5.2
  9750  -8.9  16.0  280  11  6   7.6   4.2 |  -9.6  14.7  290  11  6   7.8   4.3
  9500  -8.3  17.1  280  10  5   8.5   4.7 |  -8.9  16.0  290  10  5   8.6   4.7
  9250  -7.7  18.1  280  10  5   9.3   5.1 |  -8.3  17.1  290  10  5   9.8   5.4
  9000  -6.9  19.6  280   9  5   9.7   5.3 |  -7.5  18.5  290   9  5  10.0   5.5
  8750  -6.2  20.8  280   8  4   9.1   5.0 |  -6.8  19.8  290   9  5   9.1   5.0
  8500  -5.5  22.1  280   8  4   9.5   5.2 |  -6.1  21.0  290   9  4   9.0   5.0
  8250  -4.8  23.4  285   8  4  10.3   5.6 |  -5.5  22.1  290   8  4   9.2   5.0
  8000  -4.0  24.8  285   7  4  10.2   5.6 |  -4.8  23.4  290   8  4   9.2   5.0
  7750  -3.3  26.1  285   7  4   9.1   5.0 |  -4.1  24.6  285   8  4   9.5   5.2
  7500  -2.6  27.3  285   7  4   9.4   5.2 |  -3.4  25.9  285   7  4   9.7   5.3
  7250  -1.9  28.6  285   7  4  10.3   5.6 |  -2.6  27.3  285   7  3   9.6   5.3
  7000  -1.1  30.0  285   7  4  10.1   5.5 |  -1.9  28.6  285   6  3   9.6   5.2
  6750  -0.4  31.3  285   7  3   9.7   5.3 |  -1.2  29.8  285   6  3   9.8   5.4
  6500   0.3  32.5  285   7  3   9.7   5.3 |  -0.5  31.1  285   6  3   9.9   5.4
  6250   1.1  34.0  285   6  3  10.2   5.6 |   0.3  32.5  285   5  3  10.4   5.7
  6000   1.8  35.2  285   6  3   9.6   5.3 |   1.0  33.8  285   5  3   8.6   4.7
  5750   2.6  36.7  285   6  3  12.4   6.8 |   1.6  34.9  285   5  2   7.9   4.3
  5500   3.8  38.8  285   6  3  18.3  10.0 |   2.3  36.1  285   4  2  12.0   6.6
________________________________________________________________________________

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.

CINH (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.