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

000
UXUS97 KBOU 150039
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1739 MST Sunday, December 14, 2014

This forecast is for Monday, December 15, 2014:

If the trigger temperature of 42.2 F/5.7 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 7584 ft MSL (2297 ft AGL)

Forecast maximum temperature................... 38.0 F/3.8 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 5838 ft MSL (551 ft AGL)
Thermal soaring outlook for Tuesday 12/16...... 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)................ Weak NVA
Potential height of wave....................... 14393 ft MSL (9106 ft AGL)
Wave soaring outlook for Tuesday 12/16......... Fair

Remarks... Deep upper low over extreme southwest kansas races east-northeast
           acrosss kansas overnight. Upper ridge builds in from the west on
           Monday.

Sunrise/Sunset.................... 07:13:26 / 16:36:04 MST
Total possible sunshine........... 9 hr 22 min 38 sec (562 min 38 sec)
Altitude of sun at 11:54:47 MST... 27.01 degrees

Upper air data from numerical model forecast valid on 12/15/2014 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 12195 ft MSL (6908 ft AGL)
Lifted condensation level....... 10212 ft MSL (4925 ft AGL)
Lifted index.................... +13.2
K index......................... +5.7

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  -58.3 -72.9   285   41   21   4.5   2.5      M     M       M      M    M
 45000  -51.2 -60.2   285   53   27   3.8   2.1      M     M       M      M    M
 40000  -46.7 -52.1   285   55   28   3.0   1.7      M     M       M      M    M
 38000  -46.0 -50.8   285   54   28  -2.0  -1.1      M     M       M      M    M
 36000  -47.2 -53.0   285   50   26  -2.0  -1.1      M     M       M      M    M
 34000  -48.4 -55.1   280   47   24  -2.2  -1.2      M     M       M      M    M
 32000  -47.3 -53.1   285   42   22   2.3   1.3      M     M       M      M    M
 30000  -45.7 -50.3   285   36   19   5.4   3.0   31.2  88.1    20.8      M    M
 29000  -43.4 -46.1   290   37   19   7.4   4.1   30.1  86.1    20.3      M    M
 28000  -41.2 -42.2   290   39   20   7.4   4.1   29.1  84.4    19.8      M    M
 27000  -39.0 -38.2   290   40   21   7.4   4.1   28.3  83.0    19.4      M    M
 26000  -36.7 -34.1   290   41   21   7.8   4.3   27.5  81.5    19.0      M    M
 25000  -34.4 -29.9   295   41   21   7.8   4.3   26.7  80.1    18.6      M    M
 24000  -32.0 -25.6   295   41   21   7.8   4.3   26.0  78.9    18.3      M    M
 23000  -29.9 -21.8   295   38   20   6.3   3.5   25.1  77.2    17.7      M    M
 22000  -28.0 -18.4   290   32   17   6.3   3.4   23.8  74.8    16.9      M    M
 21000  -26.1 -15.0   285   27   14   6.4   3.5   22.6  72.7    16.1      M    M
 20000  -24.5 -12.1   285   24   13   5.0   2.7   21.0  69.8    15.0      M    M
 19500  -23.7 -10.7   285   24   12   5.0   2.7   20.2  68.3    14.3      M    M
 19000  -23.0  -9.4   285   24   12   5.0   2.7   19.3  66.8    13.7      M    M
 18500  -22.2  -8.0   285   23   12   5.0   2.8   18.5  65.4    13.1      M    M
 18000  -21.5  -6.7   285   23   12   4.7   2.6   17.8  64.0    12.4      M    M
 17500  -20.8  -5.4   285   22   11   4.7   2.6   16.8  62.3    11.7      M    M
 17000  -20.2  -4.4   285   22   11   4.9   2.7   16.0  60.8    11.0      M    M
 16500  -19.4  -2.9   290   20   11   5.9   3.2   15.3  59.5    10.4      M    M
 16000  -18.5  -1.3   295   19   10   6.1   3.4   14.6  58.3     9.8      M    M
 15500  -17.5   0.5   300   19   10   3.6   2.0   13.2  55.8     8.7      M    M
 15000  -17.0   1.4   305   20   10   3.7   2.0   12.2  54.0     7.8      M    M
 14500  -16.5   2.3   310   20   11   4.0   2.2   11.2  52.2     6.9      M    M
 14000  -15.9   3.4   320   21   11   3.9   2.1   10.3  50.5     6.1      M    M
 13500  -15.0   5.0   325   22   12   7.4   4.1    9.6  49.3     5.5      M    M
 13000  -14.0   6.8   330   24   12   7.0   3.8    9.2  48.6     5.1      M    M
 12500  -12.8   9.0   330   26   13   8.4   4.6    8.9  47.9     4.8      M    M
 12000  -11.6  11.1   330   27   14   8.3   4.6    8.6  47.5     4.6      M    M
 11500  -10.4  13.3   330   28   14   7.2   4.0    8.3  46.9     4.4      M    M
 11000   -9.3  15.3   330   29   15   7.4   4.1    7.9  46.2     4.0      M    M
 10500   -8.4  16.9   325   29   15   5.0   2.7    7.3  45.2     3.5      M    M
 10250   -8.1  17.4   325   29   15   4.5   2.5    6.9  44.5     3.1      M    M
 10000   -7.7  18.1   325   29   15   7.4   4.0    6.6  43.8     2.8      M    M
  9750   -7.0  19.4   320   29   15   8.1   4.4    6.5  43.7     2.7      M    M
  9500   -6.6  20.1   320   29   15   5.5   3.0    6.2  43.2     2.4      M    M
  9250   -6.1  21.0   320   28   15   6.5   3.6    5.9  42.7     2.2      M    M
  9000   -5.7  21.7   320   28   14   5.3   2.9    5.7  42.2     1.9      M    M
  8750   -5.3  22.5   320   26   14   4.7   2.6    5.3  41.5     1.5      M    M
  8500   -5.0  23.0   320   25   13   5.3   2.9    4.9  40.8     1.2      M    M
  8250   -4.6  23.7   320   24   12   5.1   2.8    4.5  40.2     0.8      M    M
  8000   -4.2  24.4   320   22   12   5.9   3.3    4.2  39.6     0.5      M    M
  7750   -3.7  25.3   320   19   10   6.0   3.3    3.9  39.1     0.2      M    M
  7500   -3.3  26.1   325   17    9   5.4   3.0    3.6  38.5    -0.1    137  0.7
  7250   -2.9  26.8   325   15    8   5.6   3.1    3.3  37.9    -0.4    118  0.6
  7000   -2.5  27.5   325   13    7   5.8   3.2    3.0  37.4    -0.8     98  0.5
  6750   -2.1  28.2   330   11    6   5.2   2.9    2.7  36.8    -1.1     78  0.4
  6500   -1.8  28.8   330    8    4   4.2   2.3    2.3  36.1    -1.5     61  0.3
  6250   -1.5  29.3   335    6    3   3.0   1.7    1.8  35.3    -2.0     46  0.2
  6000   -1.4  29.5   325    3    2   2.3   1.2    1.3  34.3    -2.6     34  0.2
  5750   -1.2  29.8   250    1    0   2.7   1.5    0.7  33.3    -3.1     22  0.1
  5500   -1.1  30.0   190    3    2  -2.8  -1.5    0.1  32.1    -3.8     13  0.1

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

           12/15/2014 at 0800 MST          |       12/15/2014 at 1100 MST
                                           |
K index... +4.6  LI... +5.1                | K index... +0.7  LI... +5.6
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.5
                                           |
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 -59.1 -74.4  275  38 20   4.6   2.5 | -58.4 -73.1  270  37 19   4.3   2.4
 45000 -51.8 -61.2  280  50 26   3.8   2.1 | -51.9 -61.4  270  45 23   3.3   1.8
 40000 -47.5 -53.5  280  56 29   2.9   1.6 | -48.6 -55.5  280  57 29   2.2   1.2
 38000 -46.4 -51.5  280  56 29  -0.3  -0.2 | -47.5 -53.5  285  60 31   0.8   0.5
 36000 -46.6 -51.9  285  53 27  -0.3  -0.2 | -47.0 -52.6  285  59 31   0.8   0.5
 34000 -46.8 -52.2  285  49 25  -0.4  -0.2 | -46.5 -51.7  285  59 30   0.9   0.5
 32000 -45.1 -49.2  290  48 25   2.8   1.5 | -44.4 -47.9  290  57 29   3.3   1.8
 30000 -43.4 -46.1  290  48 25   4.4   2.4 | -42.5 -44.5  290  56 29   4.2   2.3
 29000 -41.6 -42.9  290  51 26   6.0   3.3 | -41.0 -41.8  295  60 31   5.0   2.7
 28000 -39.8 -39.6  295  55 28   6.0   3.3 | -39.5 -39.1  300  65 33   5.0   2.7
 27000 -38.0 -36.4  295  58 30   6.0   3.3 | -38.0 -36.4  300  70 36   5.0   2.7
 26000 -36.3 -33.3  295  58 30   5.7   3.1 | -36.3 -33.3  300  71 37   6.1   3.4
 25000 -34.6 -30.3  295  54 28   5.7   3.1 | -34.5 -30.1  300  70 36   6.2   3.4
 24000 -32.8 -27.0  295  50 26   5.7   3.1 | -32.6 -26.7  305  69 35   6.1   3.4
 23000 -31.2 -24.2  295  46 24   4.8   2.6 | -30.8 -23.4  305  66 34   5.5   3.0
 22000 -29.8 -21.6  295  43 22   4.8   2.6 | -29.2 -20.6  300  60 31   5.5   3.0
 21000 -28.3 -18.9  290  39 20   4.8   2.6 | -27.6 -17.7  300  54 28   5.5   3.0
 20000 -26.8 -16.2  290  36 19   5.2   2.8 | -26.2 -15.2  300  48 25   4.2   2.3
 19500 -26.0 -14.8  290  35 18   5.2   2.8 | -25.5 -13.9  300  44 23   4.1   2.3
 19000 -25.3 -13.5  290  33 17   5.2   2.9 | -24.9 -12.8  300  41 21   4.1   2.3
 18500 -24.5 -12.1  290  32 16   5.2   2.9 | -24.3 -11.7  295  37 19   4.2   2.3
 18000 -23.7 -10.7  290  31 16   4.7   2.6 | -23.7 -10.7  295  34 17   3.8   2.1
 17500 -23.1  -9.6  285  29 15   4.5   2.5 | -23.2  -9.8  295  31 16   3.6   2.0
 17000 -22.4  -8.3  285  27 14   4.6   2.5 | -22.6  -8.7  290  28 14   3.7   2.0
 16500 -21.8  -7.2  285  25 13   4.8   2.6 | -21.8  -7.2  290  24 12   4.0   2.2
 16000 -20.7  -5.3  290  21 11   5.5   3.0 | -21.2  -6.2  295  21 11   5.3   2.9
 15500 -19.8  -3.6  300  20 11   6.4   3.5 | -20.3  -4.5  305  20 10   6.6   3.6
 15000 -18.8  -1.8  310  20 10   6.6   3.6 | -19.3  -2.7  310  19 10   7.0   3.8
 14500 -17.7   0.1  315  21 11   7.6   4.2 | -18.1  -0.6  320  21 11   8.0   4.4
 14000 -16.6   2.1  320  22 12   7.6   4.2 | -17.0   1.4  330  23 12   8.0   4.4
 13500 -15.5   4.1  325  25 13   7.4   4.1 | -15.8   3.6  330  25 13   8.0   4.4
 13000 -14.4   6.1  325  27 14   7.4   4.1 | -14.6   5.7  330  27 14   8.0   4.4
 12500 -13.3   8.1  330  30 15   7.8   4.3 | -13.4   7.9  330  28 14   7.3   4.0
 12000 -12.1  10.2  330  32 16   7.8   4.3 | -12.3   9.9  330  30 15   7.3   4.0
 11500 -11.1  12.0  325  33 17   5.7   3.1 | -11.2  11.8  325  31 16   7.2   4.0
 11000 -10.3  13.5  325  34 17   5.9   3.2 | -10.2  13.6  320  33 17   7.0   3.9
 10500  -9.4  15.1  325  33 17   6.2   3.4 |  -9.3  15.3  320  33 17   5.4   2.9
 10250  -8.9  16.0  325  33 17   5.8   3.2 |  -8.9  16.0  320  34 17   6.1   3.4
 10000  -8.5  16.7  325  32 17   7.4   4.1 |  -8.4  16.9  315  34 17   3.7   2.1
  9750  -7.8  18.0  320  31 16   7.6   4.2 |  -8.2  17.2  315  33 17   4.7   2.6
  9500  -7.4  18.7  320  30 15   5.9   3.2 |  -7.7  18.1  315  32 17   7.8   4.3
  9250  -6.9  19.6  320  29 15   6.6   3.6 |  -7.2  19.0  315  31 16   7.1   3.9
  9000  -6.4  20.5  320  28 14   5.4   3.0 |  -6.7  19.9  315  30 16   6.5   3.6
  8750  -6.1  21.0  320  27 14   5.4   2.9 |  -6.2  20.8  315  29 15   6.7   3.7
  8500  -5.6  21.9  320  26 13   6.4   3.5 |  -5.7  21.7  315  27 14   7.5   4.1
  8250  -5.2  22.6  320  25 13   6.2   3.4 |  -5.1  22.8  310  26 13   7.4   4.1
  8000  -4.7  23.5  320  23 12   6.4   3.5 |  -4.5  23.9  315  24 12   8.1   4.5
  7750  -4.2  24.4  320  20 11   6.6   3.6 |  -3.9  25.0  315  22 11   7.6   4.2
  7500  -3.7  25.3  320  19 10   6.5   3.6 |  -3.4  25.9  315  20 10   6.9   3.8
  7250  -3.3  26.1  325  17  9   7.0   3.9 |  -2.9  26.8  315  18  9   7.0   3.8
  7000  -2.7  27.1  325  15  8   8.0   4.4 |  -2.4  27.7  315  16  8   7.1   3.9
  6750  -2.1  28.2  325  13  7   6.9   3.8 |  -1.9  28.6  310  13  7   6.4   3.5
  6500  -1.7  28.9  325  11  6   4.9   2.7 |  -1.4  29.5  310  11  5   6.9   3.8
  6250  -1.4  29.5  320   9  5   3.1   1.7 |  -0.8  30.6  310   9  5   8.6   4.7
  6000  -1.2  29.8  310   6  3   2.9   1.6 |  -0.2  31.6  305   8  4   8.5   4.7
  5750  -1.0  30.2  285   4  2   2.3   1.3 |   0.4  32.7  305   7  3   9.2   5.1
  5500  -1.1  30.0  240   4  2  -6.9  -3.8 |   1.2  34.2  300   6  3  12.2   6.7

           12/15/2014 at 1400 MST          |       12/15/2014 at 1700 MST
                                           |
K index... +1.0  LI... +6.6                | K index... -3.5  LI... +8.8
CAPE... 0.0  CIN... -0.9                   | CAPE... 0.0  CIN... M
                                           |
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 -58.8 -73.8  270  40 21   4.1   2.2 | -59.6 -75.3  280  38 20   4.4   2.4
 45000 -52.7 -62.9  270  54 28   3.2   1.8 | -53.0 -63.4  275  51 26   3.3   1.8
 40000 -49.4 -56.9  280  57 29   2.2   1.2 | -49.3 -56.7  285  54 28   2.5   1.4
 38000 -48.3 -54.9  285  61 31   0.9   0.5 | -48.6 -55.5  285  61 31  -0.8  -0.4
 36000 -47.8 -54.0  285  70 36   0.9   0.5 | -49.0 -56.2  280  78 40  -0.7  -0.4
 34000 -47.1 -52.8  290  80 41   2.4   1.3 | -49.4 -56.9  280  95 49   1.7   0.9
 32000 -45.4 -49.7  290  77 40   2.8   1.6 | -48.1 -54.6  285  88 45   2.1   1.1
 30000 -43.7 -46.7  295  75 38   4.9   2.7 | -46.5 -51.7  295  84 43   8.0   4.4
 29000 -41.9 -43.4  295  76 39   5.8   3.2 | -44.0 -47.2  295  85 44   8.4   4.6
 28000 -40.2 -40.4  300  77 40   5.8   3.2 | -41.5 -42.7  295  86 44   8.4   4.6
 27000 -38.5 -37.3  305  78 40   5.8   3.2 | -39.0 -38.2  300  87 45   8.3   4.6
 26000 -36.6 -33.9  305  79 41   6.4   3.5 | -36.4 -33.5  300  89 46   8.8   4.8
 25000 -34.7 -30.5  305  79 41   6.4   3.5 | -33.7 -28.7  305  92 47   8.8   4.8
 24000 -32.8 -27.0  305  80 41   6.4   3.5 | -31.1 -24.0  305  95 49   8.9   4.9
 23000 -30.7 -23.3  305  78 40   7.1   3.9 | -28.8 -19.8  310  93 48   7.0   3.9
 22000 -28.6 -19.5  300  73 38   7.1   3.9 | -26.7 -16.1  310  89 46   7.0   3.8
 21000 -26.5 -15.7  300  69 36   7.3   4.0 | -24.6 -12.3  310  85 44   7.1   3.9
 20000 -24.9 -12.8  300  62 32   4.4   2.4 | -23.0  -9.4  310  76 39   4.7   2.6
 19500 -24.3 -11.7  300  58 30   4.4   2.4 | -22.3  -8.1  310  71 36   4.7   2.6
 19000 -23.6 -10.5  300  53 28   4.4   2.4 | -21.6  -6.9  305  65 34   4.7   2.6
 18500 -22.9  -9.2  300  49 25   4.5   2.5 | -20.9  -5.6  305  60 31   5.0   2.7
 18000 -22.3  -8.1  300  45 23   3.3   1.8 | -20.4  -4.7  305  55 28   1.9   1.0
 17500 -21.9  -7.4  300  39 20   3.1   1.7 | -20.1  -4.2  305  49 25   2.0   1.1
 17000 -21.4  -6.5  300  34 18   3.5   1.9 | -19.8  -3.6  305  42 22   2.8   1.5
 16500 -20.5  -4.9  305  30 15   4.5   2.4 | -19.0  -2.2  310  36 19   3.6   1.9
 16000 -19.8  -3.6  310  27 14   5.9   3.2 | -18.4  -1.1  310  33 17   4.9   2.7
 15500 -18.8  -1.8  310  26 13   6.8   3.7 | -17.7   0.1  315  31 16   5.3   2.9
 15000 -17.8  -0.0  315  25 13   7.2   3.9 | -16.9   1.6  320  30 15   5.8   3.2
 14500 -16.7   1.9  320  26 13   7.8   4.3 | -15.9   3.4  325  32 16   6.4   3.5
 14000 -15.5   4.1  325  28 14   7.7   4.2 | -15.0   5.0  330  33 17   5.9   3.2
 13500 -14.4   6.1  330  30 15   6.9   3.8 | -14.3   6.3  330  33 17   4.7   2.6
 13000 -13.4   7.9  330  32 16   6.9   3.8 | -13.6   7.5  330  33 17   5.0   2.8
 12500 -12.5   9.5  330  33 17   6.0   3.3 | -12.7   9.1  335  31 16   6.1   3.4
 12000 -11.6  11.1  330  33 17   6.0   3.3 | -11.8  10.8  335  30 15   5.9   3.2
 11500 -10.7  12.7  330  33 17   5.4   2.9 | -11.0  12.2  335  27 14   5.2   2.9
 11000  -9.9  14.2  325  32 16   5.6   3.1 | -10.3  13.5  335  25 13   5.6   3.1
 10500  -9.0  15.8  325  31 16   6.2   3.4 |  -9.3  15.3  335  22 11   6.2   3.4
 10250  -8.6  16.5  325  31 16   6.9   3.8 |  -8.9  16.0  335  21 11   6.6   3.6
 10000  -8.1  17.4  320  30 15   4.0   2.2 |  -8.4  16.9  335  20 10   4.5   2.5
  9750  -7.9  17.8  320  30 15   4.7   2.6 |  -8.1  17.4  335  20 10   6.3   3.5
  9500  -7.4  18.7  320  28 15   8.0   4.4 |  -7.4  18.7  335  20 10   9.8   5.4
  9250  -6.8  19.8  315  27 14   7.1   3.9 |  -6.8  19.8  330  19 10   8.3   4.6
  9000  -6.3  20.7  315  26 13   6.8   3.7 |  -6.2  20.8  330  19 10   6.2   3.4
  8750  -5.8  21.6  315  24 12   7.2   4.0 |  -5.8  21.6  330  19 10   6.8   3.7
  8500  -5.2  22.6  315  22 11   7.9   4.4 |  -5.2  22.6  330  18  9   8.3   4.5
  8250  -4.6  23.7  315  20 10   8.2   4.5 |  -4.6  23.7  330  18  9   8.0   4.4
  8000  -4.0  24.8  315  18  9   9.5   5.2 |  -4.0  24.8  330  17  9   8.2   4.5
  7750  -3.3  26.1  315  16  8   9.4   5.1 |  -3.4  25.9  330  16  8   9.0   4.9
  7500  -2.6  27.3  315  15  8   8.9   4.9 |  -2.7  27.1  330  15  8   9.6   5.3
  7250  -1.9  28.6  315  14  7   9.7   5.3 |  -2.0  28.4  335  14  7   9.1   5.0
  7000  -1.2  29.8  315  13  7  10.5   5.7 |  -1.3  29.7  335  14  7   9.1   5.0
  6750  -0.4  31.3  315  12  6   9.5   5.2 |  -0.6  30.9  335  13  7   9.0   4.9
  6500   0.3  32.5  315  12  6   9.6   5.3 |   0.1  32.2  340  12  6   9.1   5.0
  6250   1.1  34.0  315  11  6  10.6   5.8 |   0.7  33.3  340  11  6   8.9   4.9
  6000   1.8  35.2  315  11  6  10.5   5.7 |   1.4  34.5  345  10  5   9.7   5.3
  5750   2.6  36.7  315  10  5  10.2   5.6 |   2.1  35.8  345   9  5   6.9   3.8
  5500   3.4  38.1  320  10  5  11.2   6.1 |   2.3  36.1  345   7  4  -1.5  -0.8
________________________________________________________________________________

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.