Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 28 29 30 31

339
UXUS97 KBOU 141316
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0716 MDT Saturday, October 14, 2017

This forecast is for Saturday, October 14, 2017:

If the trigger temperature of 66.7 F/19.3 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 17 ft/min (0.1 m/s)
   Maximum height of thermals.................. 5871 ft MSL (593 ft AGL)

Forecast maximum temperature................... 58.0 F/14.9 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 5552 ft MSL (274 ft AGL)
Thermal soaring outlook for Sunday 10/15....... Fair

Wave Soaring Index............................. Good
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....................... 45440 ft MSL (40162 ft AGL)
Wave soaring outlook for Sunday 10/15.......... Fair

Remarks... Areas of stratus/fog early til around 9 am, then clearing but gusty
           northwest winds developing late this morning and afternoon.

Sunrise/Sunset.................... 07:09:16 / 18:21:26 MDT
Total possible sunshine........... 11 hr 12 min 10 sec (672 min 10 sec)
Altitude of sun at 12:45:21 MDT... 41.69 degrees

Upper air data from numerical model forecast valid on 10/14/2017 at 0600 MDT

Freezing level.................. 13214 ft MSL (7936 ft AGL)
Convective condensation level... 20625 ft MSL (15347 ft AGL)
Lifted condensation level....... 14469 ft MSL (9191 ft AGL)
Lifted index.................... +11.5
K index......................... -28.7

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  -64.7 -84.5   245   42   22   1.4   0.8      M     M       M      M    M
 45000  -61.6 -78.9   240   55   28   5.1   2.8      M     M       M      M    M
 40000  -53.9 -65.0   240   59   30   5.1   2.8      M     M       M      M    M
 38000  -50.7 -59.3   240   57   29   5.4   3.0      M     M       M      M    M
 36000  -47.5 -53.5   240   55   28   5.4   3.0      M     M       M      M    M
 34000  -43.6 -46.5   240   54   28   7.5   4.1      M     M       M      M    M
 32000  -38.5 -37.3   235   53   28   7.5   4.1      M     M       M      M    M
 30000  -34.4 -29.9   240   52   27   6.3   3.4   42.1 107.8    20.9      M    M
 29000  -32.5 -26.5   240   51   26   6.3   3.4   40.7 105.3    20.1      M    M
 28000  -30.6 -23.1   240   50   26   6.3   3.5   39.5 103.1    19.4      M    M
 27000  -28.7 -19.7   240   48   25   6.5   3.6   38.2 100.8    18.6      M    M
 26000  -26.7 -16.1   240   45   23   6.5   3.6   36.9  98.4    17.8      M    M
 25000  -24.8 -12.6   245   42   22   6.5   3.6   35.8  96.4    17.1      M    M
 24000  -22.8  -9.0   245   40   20   6.6   3.6   34.6  94.3    16.4      M    M
 23000  -20.8  -5.4   245   37   19   6.6   3.6   33.4  92.1    15.6      M    M
 22000  -18.8  -1.8   245   34   17   6.6   3.6   32.3  90.1    14.9      M    M
 21000  -16.7   1.9   250   32   16   7.8   4.3   31.3  88.4    14.2      M    M
 20000  -14.4   6.1   250   31   16   7.8   4.3   30.6  87.1    13.8      M    M
 19500  -13.2   8.2   255   31   16   7.8   4.3   30.3  86.5    13.5      M    M
 19000  -12.0  10.4   255   31   16   7.9   4.3   30.0  85.9    13.4      M    M
 18500  -10.9  12.4   255   31   16   6.8   3.7   29.6  85.2    13.1      M    M
 18000   -9.9  14.2   255   31   16   6.8   3.7   29.0  84.3    12.7      M    M
 17500   -8.9  16.0   255   30   16   6.9   3.8   28.5  83.4    12.3      M    M
 17000   -7.8  18.0   255   30   15   7.1   3.9   28.1  82.5    12.0      M    M
 16500   -6.8  19.8   255   30   15   7.2   3.9   27.6  81.7    11.7      M    M
 16000   -5.7  21.7   250   29   15   6.9   3.8   27.2  80.9    11.3      M    M
 15500   -4.2  24.4   250   28   14   6.9   3.8   26.4  79.6    10.8      M    M
 15000   -3.1  26.4   250   27   14   7.0   3.8   26.0  78.7    10.4      M    M
 14500   -2.1  28.2   250   25   13   7.1   3.9   25.5  77.9    10.0      M    M
 14000   -1.1  30.0   250   24   12   5.4   3.0   24.9  76.9     9.6      M    M
 13500   -0.3  31.5   250   22   11   5.5   3.0   24.2  75.6     9.0      M    M
 13000    0.5  32.9   250   21   11   5.5   3.0   23.6  74.4     8.4      M    M
 12500    1.3  34.3   255   23   12   5.5   3.0   22.9  73.1     7.7      M    M
 12000    2.1  35.8   255   25   13   5.1   2.8   22.2  71.9     7.1      M    M
 11500    2.8  37.0   260   25   13   5.1   2.8   21.4  70.5     6.4      M    M
 11000    3.5  38.3   260   25   13   5.5   3.0   20.7  69.2     5.6      M    M
 10500    4.3  39.7   260   23   12   4.8   2.6   20.0  68.1     5.0      M    M
 10250    4.7  40.5   260   22   11   9.6   5.2   19.7  67.5     4.7      M    M
 10000    5.6  42.1   260   22   11  11.3   6.2   19.9  67.9     4.9      M    M
  9750    6.2  43.2   260   21   11   7.8   4.3   19.8  67.7     4.8      M    M
  9500    6.9  44.4   260   19   10   9.0   4.9   19.7  67.5     4.7      M    M
  9250    7.5  45.5   260   18    9   7.9   4.3   19.7  67.4     4.6      M    M
  9000    8.1  46.6   260   18    9   8.1   4.5   19.5  67.1     4.5      M    M
  8750    8.7  47.7   260   17    9   9.1   5.0   19.4  67.0     4.4      M    M
  8500    9.4  48.9   260   16    8   8.8   4.8   19.4  66.9     4.4      M    M
  8250   10.1  50.2   260   15    8   9.3   5.1   19.3  66.8     4.3      M    M
  8000   10.8  51.4   260   14    7   9.4   5.2   19.3  66.7     4.3      M    M
  7750   11.4  52.5   260   13    7   8.3   4.6   19.2  66.6     4.3      M    M
  7500   12.0  53.6   260   12    6   8.0   4.4   19.1  66.4     4.1      M    M
  7250   12.6  54.7   260   11    6   7.8   4.3   19.0  66.1     4.0      M    M
  7000   13.2  55.8   260   11    6   7.2   4.0   18.8  65.8     3.8      M    M
  6750   13.7  56.7   260   10    5   7.7   4.2   18.6  65.5     3.7      M    M
  6500   14.2  57.6   255    9    5   2.3   1.2   18.3  65.0     3.4      M    M
  6250   13.9  57.0   250    9    5  -8.1  -4.4   17.3  63.2     2.4      M    M
  6000   13.2  55.8   240    8    4  -9.2  -5.0   15.9  60.5     0.9      M    M
  5750   12.4  54.3   230    8    4 -14.5  -8.0   14.4  57.9    -0.6     23  0.1
  5500   10.4  50.7   215    7    4 -38.4 -21.1   11.7  53.1    -3.3     75  0.4

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

           10/14/2017 at 0900 MDT          |       10/14/2017 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +9.3        | CAPE...     0.0    LI...      +11.7
CINH...     0.0    K Index... -30.0        | CINH...     0.0    K Index... -19.2
                                           |
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 -64.7 -84.5  245  47 24   2.4   1.3 | -63.1 -81.6  245  45 23   1.1   0.6
 45000 -60.4 -76.7  240  55 28   5.0   2.7 | -60.4 -76.7  240  55 28   5.2   2.8
 40000 -53.0 -63.4  235  59 30   4.9   2.7 | -52.7 -62.9  240  57 29   5.1   2.8
 38000 -49.9 -57.8  235  58 30   5.1   2.8 | -49.5 -57.1  240  56 29   5.3   2.9
 36000 -46.9 -52.4  235  56 29   5.1   2.8 | -46.3 -51.3  240  55 28   5.3   2.9
 34000 -43.6 -46.5  240  54 28   5.7   3.1 | -43.1 -45.6  240  52 27   5.5   3.0
 32000 -40.2 -40.4  240  52 27   5.7   3.1 | -39.8 -39.6  240  49 25   5.5   3.0
 30000 -36.0 -32.8  240  50 26   7.0   3.8 | -35.9 -32.6  240  47 24   6.2   3.4
 29000 -33.9 -29.0  240  48 25   7.0   3.8 | -34.0 -29.2  240  46 24   6.2   3.4
 28000 -31.8 -25.2  245  47 24   6.9   3.8 | -32.2 -26.0  245  45 23   6.2   3.4
 27000 -29.9 -21.8  245  45 23   6.1   3.4 | -30.3 -22.5  245  45 23   5.9   3.3
 26000 -28.0 -18.4  245  43 22   6.1   3.4 | -28.5 -19.3  245  45 23   6.0   3.3
 25000 -26.2 -15.2  245  40 21   6.1   3.4 | -26.8 -16.2  245  44 23   6.0   3.3
 24000 -24.2 -11.6  245  37 19   8.1   4.4 | -24.9 -12.8  250  44 23   7.2   3.9
 23000 -21.8  -7.2  245  33 17   7.9   4.3 | -22.7  -8.9  250  44 23   7.4   4.1
 22000 -19.5  -3.1  240  29 15   7.9   4.3 | -20.5  -4.9  250  43 22   7.4   4.1
 21000 -17.0   1.4  240  26 14   8.5   4.7 | -18.2  -0.8  250  42 21   8.4   4.6
 20000 -14.5   5.9  245  28 14   8.5   4.7 | -15.7   3.7  245  37 19   8.3   4.5
 19500 -13.2   8.2  245  28 14   8.5   4.7 | -14.5   5.9  240  34 18   8.3   4.5
 19000 -11.9  10.6  245  29 15   8.7   4.8 | -13.2   8.2  235  32 17   8.4   4.6
 18500 -10.8  12.6  250  29 15   6.5   3.5 | -12.1  10.2  235  30 16   6.0   3.3
 18000  -9.8  14.4  250  29 15   6.4   3.5 | -11.3  11.7  235  29 15   5.3   2.9
 17500  -8.9  16.0  250  28 15   6.3   3.5 | -10.5  13.1  230  27 14   5.0   2.8
 17000  -8.0  17.6  250  28 15   6.1   3.3 |  -9.9  14.2  235  28 14   3.0   1.7
 16500  -7.0  19.4  250  29 15   6.2   3.4 |  -9.5  14.9  240  29 15   3.3   1.8
 16000  -6.2  20.8  245  28 14   5.3   2.9 |  -9.0  15.8  245  30 15   1.2   0.6
 15500  -5.4  22.3  245  27 14   5.4   3.0 |  -8.8  16.2  250  30 16   1.4   0.8
 15000  -4.1  24.6  245  25 13   5.7   3.1 |  -8.7  16.3  250  29 15   0.0   0.0
 14500  -3.3  26.1  240  24 12   5.7   3.1 |  -8.7  16.3  250  27 14   0.2   0.1
 14000  -2.4  27.7  240  24 12   6.0   3.3 |  -8.7  16.3  255  25 13   0.6   0.3
 13500  -1.5  29.3  245  23 12   6.0   3.3 |  -8.7  16.3  260  23 12   0.6   0.3
 13000  -0.7  30.7  245  23 12   5.1   2.8 |  -8.5  16.7  265  21 11   3.6   2.0
 12500   0.0  32.0  250  24 12   5.0   2.7 |  -7.9  17.8  275  19 10   4.3   2.4
 12000   0.7  33.3  250  25 13   3.6   2.0 |  -7.1  19.2  285  17  9   7.8   4.3
 11500   1.1  34.0  255  25 13   3.1   1.7 |  -5.8  21.6  285  17  9   9.0   4.9
 11000   1.6  34.9  260  25 13   3.7   2.0 |  -4.4  24.1  290  16  8   9.1   5.0
 10500   2.1  35.8  265  23 12   4.4   2.4 |  -3.0  26.6  295  15  8  10.0   5.5
 10250   2.4  36.3  265  22 12   2.2   1.2 |  -2.4  27.7  300  15  8   5.5   3.0
 10000   2.5  36.5  265  21 11   4.2   2.3 |  -2.1  28.2  300  15  8   6.6   3.6
  9750   3.0  37.4  270  19 10   7.8   4.3 |  -1.3  29.7  300  15  8  11.9   6.5
  9500   3.6  38.5  270  18  9   7.0   3.9 |  -0.5  31.1  305  15  7  10.8   5.9
  9250   4.1  39.4  275  16  8   6.6   3.6 |   0.4  32.7  305  14  7  10.1   5.6
  9000   4.5  40.1  275  15  8   6.5   3.6 |   1.1  34.0  305  14  7   9.4   5.1
  8750   5.1  41.2  275  15  8   7.8   4.3 |   1.8  35.2  310  14  7  10.2   5.6
  8500   5.6  42.1  280  14  7   7.5   4.1 |   2.6  36.7  310  14  7  10.3   5.7
  8250   6.2  43.2  280  14  7   8.7   4.7 |   3.3  37.9  310  14  7  10.1   5.6
  8000   6.9  44.4  285  13  7   9.7   5.3 |   4.1  39.4  310  14  7  10.0   5.5
  7750   7.6  45.7  285  12  6   8.4   4.6 |   4.8  40.6  310  14  7  10.1   5.5
  7500   8.2  46.8  290  12  6   7.9   4.3 |   5.6  42.1  310  14  7  10.0   5.5
  7250   8.8  47.8  290  11  6   7.8   4.3 |   6.3  43.3  310  14  7   9.9   5.4
  7000   9.3  48.7  295  10  5   7.2   3.9 |   7.1  44.8  310  14  7   9.9   5.4
  6750   9.9  49.8  300  10  5   9.2   5.0 |   7.8  46.0  310  14  7  10.1   5.6
  6500  10.5  50.9  305   9  5   4.5   2.4 |   8.6  47.5  315  14  7  10.9   6.0
  6250  10.5  50.9  310   8  4  -2.7  -1.5 |   9.4  48.9  315  13  7  11.4   6.2
  6000  10.2  50.4  315   7  4  -2.3  -1.3 |  10.3  50.5  315  13  7  10.7   5.9
  5750  10.0  50.0  325   6  3  -3.0  -1.7 |  11.1  52.0  315  12  6  12.2   6.7
  5500   9.6  49.3  330   4  2  -6.2  -3.4 |  12.2  54.0  315  11  6  18.8  10.3

           10/14/2017 at 1500 MDT          |       10/14/2017 at 1800 MDT
                                           |
CAPE...    +3.6    LI...      +10.7        | CAPE...     0.0    LI...      +10.4
CINH...   -11.6    K Index...  +7.7        | CINH...     0.0    K Index... -17.1
                                           |
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 -59.5 -75.1  250  39 20   0.2   0.1 | -59.3 -74.7  260  34 18   1.4   0.8
 45000 -58.5 -73.3  250  52 27   3.4   1.9 | -56.8 -70.2  255  43 22   3.5   1.9
 40000 -53.3 -63.9  245  49 25   3.5   1.9 | -51.4 -60.5  255  46 24   3.6   2.0
 38000 -50.7 -59.3  250  48 25   4.6   2.5 | -49.5 -57.1  255  44 23   3.1   1.7
 36000 -48.0 -54.4  250  47 24   4.6   2.5 | -47.6 -53.7  255  40 21   3.1   1.7
 34000 -44.9 -48.8  255  46 24   6.0   3.3 | -45.1 -49.2  260  38 20   4.5   2.5
 32000 -40.8 -41.4  250  46 24   6.0   3.3 | -42.4 -44.3  265  39 20   4.5   2.5
 30000 -37.0 -34.6  255  45 23   6.8   3.7 | -39.1 -38.4  265  38 20   6.9   3.8
 29000 -35.0 -31.0  255  43 22   6.8   3.7 | -37.1 -34.8  265  37 19   6.8   3.8
 28000 -32.9 -27.2  255  42 22   6.8   3.7 | -35.0 -31.0  270  36 19   6.8   3.8
 27000 -30.9 -23.6  260  41 21   6.5   3.6 | -33.0 -27.4  270  35 18   6.7   3.7
 26000 -28.9 -20.0  260  42 21   6.5   3.6 | -31.0 -23.8  270  34 18   6.7   3.7
 25000 -27.0 -16.6  260  42 22   6.5   3.6 | -29.0 -20.2  270  34 17   6.7   3.7
 24000 -25.0 -13.0  260  43 22   7.4   4.1 | -26.9 -16.4  270  33 17   7.7   4.2
 23000 -22.6  -8.7  255  40 21   7.9   4.4 | -24.4 -11.9  265  30 16   8.3   4.5
 22000 -20.2  -4.4  245  38 19   8.0   4.4 | -22.0  -7.6  265  28 14   8.3   4.6
 21000 -18.0  -0.4  240  36 19   4.6   2.5 | -19.7  -3.5  260  25 13   3.5   1.9
 20000 -16.8   1.8  245  37 19   4.3   2.3 | -18.7  -1.7  275  23 12   3.5   1.9
 19500 -16.1   3.0  245  37 19   4.3   2.3 | -18.2  -0.8  280  22 11   3.5   1.9
 19000 -15.5   4.1  245  38 19   4.1   2.3 | -17.6   0.3  285  22 11   3.5   1.9
 18500 -14.9   5.2  245  38 19   1.1   0.6 | -17.1   1.2  295  21 11   2.9   1.6
 18000 -15.1   4.8  245  36 19  -1.1  -0.6 | -16.7   1.9  300  22 11   2.6   1.5
 17500 -15.3   4.5  245  34 18  -1.2  -0.6 | -16.3   2.7  305  22 12   2.6   1.4
 17000 -15.8   3.6  250  32 16  -4.9  -2.7 | -15.8   3.6  310  22 12   2.3   1.3
 16500 -16.9   1.6  250  27 14  -3.6  -2.0 | -15.5   4.1  315  22 12   2.7   1.5
 16000 -17.1   1.2  255  23 12  -0.1  -0.1 | -15.0   5.0  315  22 11   3.3   1.8
 15500 -17.2   1.0  255  20 10  -0.8  -0.5 | -14.5   5.9  315  21 11   3.3   1.8
 15000 -16.6   2.1  255  17  9   9.4   5.1 | -14.0   6.8  320  21 11   4.2   2.3
 14500 -15.3   4.5  260  16  8   8.5   4.7 | -13.4   7.9  320  20 10   4.0   2.2
 14000 -14.1   6.6  265  15  8   7.7   4.2 | -12.7   9.1  320  20 10   5.3   2.9
 13500 -13.0   8.6  270  15  8   7.7   4.2 | -11.9  10.6  320  19 10   5.1   2.8
 13000 -11.9  10.6  280  15  8   7.5   4.1 | -11.1  12.0  320  18  9   6.0   3.3
 12500 -10.7  12.7  285  14  7   7.5   4.1 | -10.2  13.6  320  17  9   5.9   3.3
 12000  -9.6  14.7  295  14  7   7.8   4.3 |  -9.3  15.3  320  16  8   6.7   3.7
 11500  -8.5  16.7  300  13  7   7.7   4.2 |  -8.3  17.1  320  15  8   6.6   3.6
 11000  -7.2  19.0  305  13  7   9.4   5.1 |  -7.3  18.9  315  14  7   7.6   4.2
 10500  -5.8  21.6  310  13  7  10.4   5.7 |  -6.2  20.8  315  13  7   7.6   4.2
 10250  -5.1  22.8  315  13  7   5.1   2.8 |  -5.6  21.9  315  12  6   6.6   3.6
 10000  -4.9  23.2  315  13  7   5.6   3.1 |  -5.2  22.6  315  12  6   6.8   3.7
  9750  -4.1  24.6  315  13  7  13.1   7.2 |  -4.6  23.7  315  12  6   8.5   4.7
  9500  -3.2  26.2  315  13  7  12.5   6.9 |  -3.9  25.0  315  11  6   8.7   4.8
  9250  -2.3  27.9  320  13  7   9.3   5.1 |  -3.3  26.1  315  11  6   8.3   4.5
  9000  -1.7  28.9  320  13  7   7.9   4.3 |  -2.7  27.1  315  11  5   8.2   4.5
  8750  -1.0  30.2  320  13  7  11.5   6.3 |  -2.1  28.2  315  10  5   9.9   5.5
  8500  -0.1  31.8  320  13  7  11.5   6.3 |  -1.3  29.7  315  10  5  10.1   5.5
  8250   0.7  33.3  320  13  7   9.3   5.1 |  -0.6  30.9  315  10  5   9.1   5.0
  8000   1.3  34.3  320  13  7   9.0   4.9 |   0.1  32.2  315  10  5   9.0   4.9
  7750   2.1  35.8  320  13  7  10.8   5.9 |   0.8  33.4  315  10  5  10.9   6.0
  7500   2.9  37.2  320  13  7  10.6   5.8 |   1.7  35.1  315   9  5  10.9   6.0
  7250   3.6  38.5  320  13  7   9.2   5.0 |   2.4  36.3  315   9  5   9.2   5.1
  7000   4.3  39.7  320  13  7   9.3   5.1 |   3.1  37.6  315   9  5   9.3   5.1
  6750   5.0  41.0  320  13  7  10.3   5.7 |   3.8  38.8  315   9  5   9.1   5.0
  6500   5.9  42.6  320  13  7  10.9   6.0 |   4.5  40.1  315   9  4   9.8   5.4
  6250   6.6  43.9  320  13  7  10.3   5.6 |   5.2  41.4  315   8  4   9.8   5.4
  6000   7.4  45.3  320  13  6  10.3   5.6 |   6.0  42.8  315   8  4  10.4   5.7
  5750   8.2  46.8  320  12  6  12.1   6.6 |   6.7  44.1  315   7  4   9.3   5.1
  5500   9.2  48.6  320  11  5  15.8   8.7 |   7.2  45.0  315   6  3   5.4   3.0
________________________________________________________________________________

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.