Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 240119
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1819 MST Tuesday, January 23, 2018

This forecast is for Wednesday, January 24, 2018:

If the trigger temperature of 50.2 F/10.1 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 301 ft/min (1.5 m/s)
   Maximum height of thermals.................. 11672 ft MSL (6365 ft AGL)

Forecast maximum temperature................... 54.0 F/12.7 C
Time of trigger temperature.................... 1245 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8220 ft MSL (2913 ft AGL)
Thermal soaring outlook for Thursday 01/25..... 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....................... 17849 ft MSL (12542 ft AGL)
Wave soaring outlook for Thursday 01/25........ Poor

Remarks...

Sunrise/Sunset.................... 07:13:41 / 17:08:36 MST
Total possible sunshine........... 9 hr 54 min 55 sec (594 min 55 sec)
Altitude of sun at 12:11:32 MST... 31.21 degrees

Upper air data from numerical model forecast valid on 01/24/2018 at 0500 MST

Freezing level.................. 5949 ft MSL (642 ft AGL)
Additional freezing level....... 8418 ft MSL (3111 ft AGL)
Convective condensation level... 19386 ft MSL (14079 ft AGL)
Lifted condensation level....... 16270 ft MSL (10964 ft AGL)
Lifted index.................... +6.3
K index......................... -2.3

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  -57.3 -71.1   295   44   22   2.7   1.5      M     M       M      M    M
 45000  -53.1 -63.6   295   50   26   3.4   1.9      M     M       M      M    M
 40000  -58.8 -73.8   315   61   31  -4.2  -2.3      M     M       M      M    M
 38000  -60.5 -76.9   320   63   33   0.3   0.2      M     M       M      M    M
 36000  -60.2 -76.4   335   61   31   0.4   0.2      M     M       M      M    M
 34000  -60.0 -76.0   350   61   32   4.3   2.3      M     M       M      M    M
 32000  -54.9 -66.8   340   57   29   8.4   4.6      M     M       M      M    M
 30000  -49.3 -56.7   325   54   28   8.4   4.6   25.9  78.5    10.2      M    M
 29000  -46.8 -52.2   330   50   26   8.4   4.6   25.2  77.4     9.8      M    M
 28000  -44.2 -47.6   330   47   24   8.4   4.6   24.7  76.5     9.6      M    M
 27000  -41.7 -43.1   330   44   23   8.6   4.7   24.3  75.8     9.4      M    M
 26000  -39.1 -38.4   330   43   22   8.9   4.9   23.9  75.0     9.2      M    M
 25000  -36.4 -33.5   325   43   22   8.9   4.9   23.6  74.4     9.0      M    M
 24000  -33.7 -28.7   325   42   22   8.9   4.9   23.3  74.0     9.0      M    M
 23000  -31.1 -24.0   320   41   21   8.7   4.8   22.9  73.2     8.7      M    M
 22000  -28.5 -19.3   320   40   21   8.8   4.8   22.5  72.6     8.5      M    M
 21000  -25.9 -14.6   315   39   20   8.3   4.6   22.2  72.0     8.4      M    M
 20000  -23.5 -10.3   315   38   20   8.1   4.4   21.6  70.8     7.9      M    M
 19500  -22.3  -8.1   315   38   20   8.1   4.4   21.3  70.3     7.7      M    M
 19000  -21.1  -6.0   315   38   19   8.1   4.4   21.0  69.8     7.5      M    M
 18500  -19.9  -3.8   315   37   19   7.7   4.2   20.8  69.4     7.3      M    M
 18000  -18.8  -1.8   315   38   19   7.3   4.0   20.3  68.6     6.9      M    M
 17500  -17.7   0.1   315   38   20   7.2   4.0   19.9  67.8     6.6      M    M
 17000  -16.7   1.9   315   38   20   6.8   3.8   19.4  67.0     6.2      M    M
 16500  -15.6   3.9   320   37   19   6.9   3.8   18.9  66.1     5.8      M    M
 16000  -14.1   6.6   320   36   19   6.9   3.8   18.2  64.8     5.2      M    M
 15500  -13.1   8.4   320   36   18   7.0   3.8   17.7  63.9     4.8      M    M
 15000  -12.1  10.2   320   35   18   5.8   3.2   17.2  62.9     4.3      M    M
 14500  -11.3  11.7   320   34   17   6.0   3.3   16.5  61.8     3.7      M    M
 14000  -10.4  13.3   325   32   17   5.7   3.1   15.9  60.6     3.2      M    M
 13500   -9.5  14.9   320   31   16   5.7   3.1   15.2  59.4     2.6      M    M
 13000   -8.7  16.3   320   29   15   5.0   2.7   14.5  58.2     2.0      M    M
 12500   -8.0  17.6   320   26   14   4.8   2.6   13.7  56.7     1.2      M    M
 12000   -7.3  18.9   315   24   12   4.5   2.5   12.9  55.2     0.5      M    M
 11500   -6.7  19.9   315   22   11   4.3   2.4   12.0  53.7    -0.4    486  2.5
 11000   -5.9  21.4   310   20   10   6.7   3.7   11.3  52.3    -1.1    448  2.3
 10500   -4.8  23.4   305   18    9   7.9   4.3   10.9  51.6    -1.4    401  2.0
 10250   -4.3  24.3   305   17    9   4.9   2.7   10.7  51.3    -1.6    377  1.9
 10000   -4.0  24.8   305   16    8   4.8   2.6   10.2  50.4    -2.1    362  1.8
  9750   -3.4  25.9   305   17    9  10.4   5.7   10.1  50.2    -2.2    337  1.7
  9500   -2.5  27.5   305   18    9  12.4   6.8   10.2  50.4    -2.1    303  1.5
  9250   -1.7  28.9   305   19   10   8.8   4.8   10.4  50.6    -2.0    270  1.4
  9000   -1.2  29.8   305   20   10   5.3   2.9   10.1  50.1    -2.3    249  1.3
  8750   -0.8  30.6   305   21   11   7.4   4.1    9.8  49.7    -2.5    228  1.2
  8500   -0.2  31.6   305   23   12   7.9   4.3    9.7  49.4    -2.7    203  1.0
  8250    0.3  32.5   300   24   12   4.9   2.7    9.4  49.0    -2.9    181  0.9
  8000    0.6  33.1   295   24   12   3.5   1.9    9.0  48.1    -3.4    165  0.8
  7750    0.9  33.6   295   24   12   3.3   1.8    8.5  47.3    -3.9    149  0.8
  7500    1.0  33.8   290   23   12   1.1   0.6    7.9  46.3    -4.4    137  0.7
  7250    1.1  34.0   290   21   11  -0.2  -0.1    7.2  44.9    -5.2    129  0.7
  7000    1.0  33.8   290   19   10  -0.2  -0.1    6.4  43.6    -5.9    122  0.6
  6750    1.0  33.8   285   17    9  -0.2  -0.1    5.7  42.2    -6.7    116  0.6
  6500    0.9  33.6   280   15    8  -2.4  -1.3    4.9  40.8    -7.5    111  0.6
  6250    0.7  33.3   275   13    7  -2.7  -1.5    3.9  39.0    -8.5    111  0.6
  6000    0.4  32.7   265   11    6  -6.2  -3.4    2.9  37.2    -9.5    111  0.6
  5750   -0.7  30.7   245    9    5 -26.6 -14.6    1.0  33.9   -11.4    137  0.7
  5500   -3.6  25.5   225    7    4 -46.4 -25.4   -2.6  27.4   -15.1    216  1.1

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

           01/24/2018 at 0800 MST          |       01/24/2018 at 1100 MST
                                           |
K index... +2.0  LI... +5.7                | K index... -2.0  LI... +4.6
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -58.5 -73.3  300  41 21   2.0   1.1 | -58.3 -72.9  290  37 19   1.9   1.1
 45000 -55.3 -67.5  305  46 24   2.6   1.4 | -55.4 -67.7  295  44 23   2.7   1.5
 40000 -60.1 -76.2  305  57 29  -3.5  -1.9 | -60.8 -77.4  305  54 28  -3.9  -2.1
 38000 -61.2 -78.2  310  59 31   1.7   1.0 | -61.7 -79.1  305  56 29   3.1   1.7
 36000 -60.1 -76.2  330  61 31   1.8   1.0 | -59.8 -75.6  310  53 27   3.1   1.7
 34000 -58.9 -74.0  345  67 35   6.3   3.5 | -57.2 -71.0  315  49 25   8.4   4.6
 32000 -53.0 -63.4  335  55 29   8.8   4.8 | -52.4 -62.3  315  41 21   8.0   4.4
 30000 -47.8 -54.0  320  49 25   8.0   4.4 | -47.6 -53.7  310  36 19   8.1   4.4
 29000 -45.4 -49.7  320  48 25   8.0   4.4 | -45.2 -49.4  310  39 20   8.1   4.4
 28000 -43.0 -45.4  315  49 25   8.0   4.4 | -42.7 -44.9  310  41 21   8.1   4.4
 27000 -40.6 -41.1  310  49 25   8.3   4.5 | -40.3 -40.5  310  44 22   8.5   4.6
 26000 -38.0 -36.4  305  46 24   8.6   4.7 | -37.7 -35.9  310  44 22   8.8   4.8
 25000 -35.4 -31.7  305  44 23   8.6   4.7 | -35.1 -31.2  310  44 22   8.8   4.8
 24000 -32.9 -27.2  300  41 21   8.4   4.6 | -32.5 -26.5  305  44 22   8.4   4.6
 23000 -30.5 -22.9  300  39 20   7.9   4.3 | -30.1 -22.2  305  43 22   7.7   4.2
 22000 -28.1 -18.6  300  37 19   7.9   4.3 | -27.9 -18.2  305  42 22   7.7   4.2
 21000 -25.8 -14.4  300  34 18   7.8   4.3 | -25.6 -14.1  305  41 21   7.6   4.2
 20000 -23.4 -10.1  305  34 17   7.8   4.3 | -23.3  -9.9  305  40 21   7.6   4.2
 19500 -22.3  -8.1  305  34 17   7.8   4.3 | -22.1  -7.8  305  39 20   7.6   4.2
 19000 -21.1  -6.0  305  33 17   7.8   4.3 | -21.0  -5.8  305  39 20   7.6   4.2
 18500 -20.0  -4.0  310  33 17   7.6   4.2 | -19.8  -3.6  305  38 19   8.2   4.5
 18000 -18.8  -1.8  310  33 17   7.5   4.1 | -17.9  -0.2  305  36 18   8.5   4.7
 17500 -17.7   0.1  310  32 16   7.5   4.1 | -16.7   1.9  305  35 18   7.7   4.2
 17000 -16.1   3.0  315  31 16   7.3   4.0 | -15.5   4.1  305  34 17   7.5   4.1
 16500 -15.0   5.0  315  31 16   7.2   3.9 | -14.4   6.1  305  33 17   7.4   4.1
 16000 -14.0   6.8  315  30 15   6.9   3.8 | -13.3   8.1  305  32 16   7.2   3.9
 15500 -13.0   8.6  315  29 15   6.9   3.8 | -12.3   9.9  305  31 16   7.1   3.9
 15000 -12.0  10.4  320  28 14   6.1   3.4 | -11.2  11.8  305  30 15   6.8   3.7
 14500 -11.1  12.0  320  27 14   6.2   3.4 | -10.2  13.6  305  29 15   6.8   3.7
 14000 -10.2  13.6  320  26 13   6.2   3.4 |  -9.2  15.4  305  27 14   7.3   4.0
 13500  -9.2  15.4  320  25 13   6.2   3.4 |  -8.1  17.4  305  26 13   7.3   4.0
 13000  -8.4  16.9  320  23 12   5.5   3.0 |  -7.0  19.4  300  25 13   7.2   4.0
 12500  -7.6  18.3  320  21 11   5.4   3.0 |  -5.9  21.4  300  23 12   7.2   4.0
 12000  -6.7  19.9  320  19 10   6.0   3.3 |  -4.9  23.2  300  21 11   7.2   3.9
 11500  -5.8  21.6  320  17  9   6.1   3.3 |  -3.8  25.2  300  20 10   7.2   3.9
 11000  -4.8  23.4  320  15  8   7.5   4.1 |  -2.7  27.1  305  18  9   7.6   4.2
 10500  -3.7  25.3  315  13  7   8.5   4.6 |  -1.6  29.1  305  17  9   8.5   4.7
 10250  -3.1  26.4  315  13  7   4.6   2.5 |  -1.0  30.2  305  17  9   4.1   2.2
 10000  -2.9  26.8  315  13  6   5.6   3.1 |  -0.8  30.6  305  16  8   5.7   3.1
  9750  -2.1  28.2  315  14  7  12.0   6.6 |  -0.0  32.0  305  18  9  12.0   6.6
  9500  -1.2  29.8  315  15  8  13.2   7.3 |   0.8  33.4  305  20 10  11.9   6.6
  9250  -0.3  31.5  320  17  9   9.7   5.3 |   1.7  35.1  305  22 11   7.6   4.2
  9000   0.3  32.5  315  18  9   6.6   3.6 |   2.0  35.6  300  23 12   3.9   2.1
  8750   0.9  33.6  315  19 10   9.2   5.1 |   2.4  36.3  300  25 13   6.8   3.7
  8500   1.6  34.9  310  21 11   9.3   5.1 |   2.9  37.2  295  25 13   6.6   3.6
  8250   2.2  36.0  310  22 12   6.0   3.3 |   3.3  37.9  295  26 13   4.5   2.5
  8000   2.5  36.5  305  22 12   4.1   2.3 |   3.6  38.5  290  26 13   3.5   1.9
  7750   2.9  37.2  295  23 12   4.9   2.7 |   3.9  39.0  290  26 13   4.2   2.3
  7500   3.2  37.8  290  23 12   1.7   1.0 |   4.2  39.6  285  25 13   3.3   1.8
  7250   3.1  37.6  290  22 11  -1.5  -0.8 |   4.4  39.9  280  22 11   2.1   1.1
  7000   3.0  37.4  285  20 10  -1.5  -0.8 |   4.5  40.1  275  19 10   2.3   1.3
  6750   2.9  37.2  280  19 10  -1.2  -0.6 |   4.7  40.5  270  16  8   2.1   1.1
  6500   2.8  37.0  275  17  9  -3.4  -1.9 |   4.8  40.6  265  14  7   0.2   0.1
  6250   2.4  36.3  265  15  8  -4.0  -2.2 |   4.8  40.6  255  13  7   0.5   0.3
  6000   2.1  35.8  255  13  7  -7.7  -4.2 |   4.7  40.5  245  12  6  -3.3  -1.8
  5750   0.8  33.4  240  12  6 -29.6 -16.2 |   4.2  39.6  235  10  5  -9.0  -4.9
  5500  -2.3  27.9  220   9  5 -50.1 -27.5 |   3.5  38.3  220   7  4  -5.5  -3.0

           01/24/2018 at 1400 MST          |       01/24/2018 at 1700 MST
                                           |
K index... -9.7  LI... +4.8                | K index... -11.7  LI... +4.7
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -58.6 -73.5  285  38 19   3.3   1.8 | -58.5 -73.3  280  38 20   3.6   2.0
 45000 -53.6 -64.5  295  44 22   4.4   2.4 | -53.1 -63.6  290  39 20   4.6   2.5
 40000 -60.0 -76.0  295  57 29  -4.6  -2.5 | -61.6 -78.9  300  54 28  -5.9  -3.2
 38000 -61.1 -78.0  300  59 30   3.1   1.7 | -62.4 -80.3  300  55 29   4.2   2.3
 36000 -59.0 -74.2  310  55 28   3.1   1.7 | -59.9 -75.8  305  52 27   4.2   2.3
 34000 -56.6 -69.9  315  52 27   8.0   4.4 | -57.1 -70.8  305  48 25   8.6   4.7
 32000 -52.0 -61.6  310  46 24   7.7   4.2 | -52.2 -62.0  300  44 23   8.2   4.5
 30000 -47.3 -53.1  310  42 21   8.5   4.7 | -47.3 -53.1  295  41 21   8.0   4.4
 29000 -44.8 -48.6  310  41 21   8.5   4.7 | -44.9 -48.8  295  38 20   8.0   4.4
 28000 -42.2 -44.0  310  41 21   8.5   4.7 | -41.9 -43.4  290  35 18   8.0   4.4
 27000 -39.7 -39.5  305  40 21   8.3   4.5 | -39.5 -39.1  290  32 17   8.3   4.6
 26000 -37.2 -35.0  305  40 21   8.1   4.4 | -37.0 -34.6  290  31 16   8.3   4.6
 25000 -34.8 -30.6  305  40 20   8.1   4.4 | -34.5 -30.1  295  30 15   8.3   4.6
 24000 -32.4 -26.3  305  39 20   8.0   4.4 | -32.0 -25.6  295  29 15   8.5   4.6
 23000 -30.0 -22.0  305  38 20   7.9   4.3 | -29.5 -21.1  300  29 15   8.5   4.7
 22000 -27.7 -17.9  300  36 19   7.9   4.3 | -26.9 -16.4  300  30 15   8.5   4.7
 21000 -25.3 -13.5  300  34 18   7.9   4.3 | -24.4 -11.9  305  30 15   8.2   4.5
 20000 -22.9  -9.2  300  31 16   7.9   4.3 | -21.9  -7.4  305  30 15   8.2   4.5
 19500 -21.7  -7.1  300  29 15   7.9   4.3 | -20.7  -5.3  305  30 15   8.3   4.5
 19000 -20.6  -5.1  300  28 14   7.9   4.3 | -19.5  -3.1  305  29 15   8.3   4.5
 18500 -18.8  -1.8  305  26 13   8.0   4.4 | -18.3  -0.9  310  29 15   7.8   4.3
 18000 -17.6   0.3  305  25 13   7.9   4.4 | -17.1   1.2  310  30 15   7.7   4.2
 17500 -16.3   2.7  305  24 12   8.6   4.7 | -16.0   3.2  310  30 15   7.9   4.3
 17000 -15.0   5.0  310  25 13   8.8   4.8 | -14.7   5.5  310  30 15   8.3   4.5
 16500 -13.7   7.3  310  26 13   8.5   4.7 | -13.5   7.7  305  30 15   8.3   4.6
 16000 -12.5   9.5  310  28 14   7.7   4.3 | -12.3   9.9  305  30 15   7.4   4.1
 15500 -11.4  11.5  310  29 15   7.8   4.3 | -11.2  11.8  305  30 16   7.5   4.1
 15000 -10.3  13.5  310  30 16   7.1   3.9 |  -9.5  14.9  305  31 16   7.7   4.2
 14500  -9.2  15.4  305  30 16   7.2   3.9 |  -8.4  16.9  305  31 16   7.7   4.2
 14000  -8.1  17.4  305  30 16   7.0   3.8 |  -7.3  18.9  305  31 16   7.3   4.0
 13500  -7.1  19.2  305  30 15   7.0   3.9 |  -6.2  20.8  300  31 16   7.3   4.0
 13000  -6.0  21.2  300  29 15   6.8   3.7 |  -5.1  22.8  300  31 16   7.0   3.9
 12500  -5.0  23.0  300  28 15   6.8   3.7 |  -4.1  24.6  300  31 16   7.0   3.8
 12000  -4.0  24.8  295  27 14   6.7   3.7 |  -3.0  26.6  295  30 16   7.5   4.1
 11500  -3.0  26.6  295  24 12   6.6   3.6 |  -1.9  28.6  295  29 15   7.6   4.2
 11000  -1.9  28.6  290  22 11   7.9   4.3 |  -0.8  30.6  290  28 15   6.9   3.8
 10500  -0.7  30.7  290  19 10   9.1   5.0 |   0.2  32.4  285  28 14   7.6   4.2
 10250  -0.1  31.8  290  18  9   4.0   2.2 |   0.7  33.3  285  27 14   3.7   2.0
 10000   0.0  32.0  285  18  9   4.9   2.7 |   0.9  33.6  280  27 14   4.0   2.2
  9750   0.7  33.3  285  20 10  10.4   5.7 |   1.4  34.5  280  26 13   8.1   4.5
  9500   1.4  34.5  285  21 11  10.0   5.5 |   1.9  35.4  275  25 13   7.5   4.1
  9250   2.1  35.8  285  23 12   6.5   3.6 |   2.4  36.3  270  24 12   6.3   3.5
  9000   2.4  36.3  285  24 12   3.8   2.1 |   2.8  37.0  270  23 12   6.3   3.5
  8750   2.8  37.0  285  24 12   7.1   3.9 |   3.4  38.1  265  21 11   8.7   4.8
  8500   3.3  37.9  280  23 12   7.6   4.2 |   4.1  39.4  265  20 10   8.8   4.8
  8250   3.9  39.0  275  22 11   7.6   4.2 |   4.7  40.5  260  18  9   8.5   4.7
  8000   4.4  39.9  270  20 10   7.6   4.1 |   5.3  41.5  260  15  8   8.4   4.6
  7750   5.0  41.0  265  18  9   7.8   4.3 |   5.9  42.6  255  14  7   8.8   4.8
  7500   5.6  42.1  260  15  8   7.0   3.8 |   6.6  43.9  255  12  6   8.4   4.6
  7250   6.0  42.8  255  13  7   5.7   3.1 |   7.2  45.0  250  11  6   7.6   4.2
  7000   6.5  43.7  250  12  6   5.6   3.1 |   7.7  45.9  250   9  5   7.7   4.2
  6750   6.9  44.4  240  10  5   5.9   3.2 |   8.3  46.9  245   8  4   7.1   3.9
  6500   7.3  45.1  230   9  4   3.8   2.1 |   8.7  47.7  240   7  4   4.6   2.6
  6250   7.4  45.3  225   8  4   2.1   1.1 |   9.0  48.2  235   6  3   2.4   1.3
  6000   7.6  45.7  215   7  4   2.8   1.5 |   9.2  48.6  230   6  3   5.9   3.2
  5750   7.8  46.0  205   6  3   3.1   1.7 |   9.5  49.1  220   5  3  -2.1  -1.1
  5500   7.9  46.2  195   5  3   2.0   1.1 |   8.3  46.9  215   4  2 -26.8 -14.7
________________________________________________________________________________

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



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