Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 080252
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1952 MST Thursday, December 7, 2017

This forecast is for Friday, December 8, 2017:

If the trigger temperature of 49.1 F/9.5 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 284 ft/min (1.4 m/s)
   Maximum height of thermals.................. 13748 ft MSL (8441 ft AGL)

Forecast maximum temperature................... 57.0 F/14.3 C
Time of trigger temperature.................... 1045 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................. 11125 ft MSL (5818 ft AGL)
Thermal soaring outlook for Saturday 12/09..... 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....................... 14636 ft MSL (9329 ft AGL)
Wave soaring outlook for Saturday 12/09........ Poor

Remarks...

Sunrise/Sunset.................... 07:08:14 / 16:34:57 MST
Total possible sunshine........... 9 hr 26 min 43 sec (566 min 43 sec)
Altitude of sun at 11:51:41 MST... 27.51 degrees

Upper air data from numerical model forecast valid on 12/08/2017 at 0500 MST

Freezing level.................. 8323 ft MSL (3016 ft AGL)
Convective condensation level... 19046 ft MSL (13739 ft AGL)
Lifted condensation level....... 16535 ft MSL (11228 ft AGL)
Lifted index.................... +7.2
K index......................... +7.1

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -60.5 -76.9   355   21   11   0.4   0.2      M     M       M      M    M
 45000  -59.9 -75.8   005   40   20   0.4   0.2      M     M       M      M    M
 40000  -61.0 -77.8   005   63   32  -0.8  -0.4      M     M       M      M    M
 38000  -60.5 -76.9   010   69   36   3.3   1.8      M     M       M      M    M
 36000  -58.5 -73.3   015   72   37   3.3   1.8      M     M       M      M    M
 34000  -56.2 -69.2   020   75   38   8.4   4.6      M     M       M      M    M
 32000  -51.4 -60.5   020   75   39   8.1   4.4      M     M       M      M    M
 30000  -46.6 -51.9   020   76   39   8.3   4.5   29.9  85.8    12.0      M    M
 29000  -44.1 -47.4   020   76   39   8.3   4.6   29.2  84.6    11.6      M    M
 28000  -41.0 -41.8   015   76   39   8.3   4.6   28.5  83.4    11.2      M    M
 27000  -38.5 -37.3   015   76   39   8.4   4.6   28.1  82.6    11.1      M    M
 26000  -36.0 -32.8   015   73   38   8.4   4.6   27.5  81.5    10.7      M    M
 25000  -33.5 -28.3   015   71   37   8.4   4.6   27.0  80.5    10.4      M    M
 24000  -31.0 -23.8   015   68   35   8.0   4.4   26.6  79.9    10.2      M    M
 23000  -28.8 -19.8   015   66   34   7.3   4.0   25.6  78.1     9.5      M    M
 22000  -26.7 -16.1   015   63   32   7.3   4.0   24.7  76.5     8.9      M    M
 21000  -24.5 -12.1   015   61   31   6.6   3.6   23.9  75.0     8.2      M    M
 20000  -22.6  -8.7   010   60   31   6.5   3.6   22.6  72.7     7.2      M    M
 19500  -21.7  -7.1   010   59   30   6.5   3.6   22.1  71.7     6.8      M    M
 19000  -20.7  -5.3   010   59   30   6.5   3.6   21.5  70.7     6.3      M    M
 18500  -19.8  -3.6   010   58   30   6.6   3.6   21.0  69.8     5.9      M    M
 18000  -18.8  -1.8   010   59   30   6.7   3.7   20.5  68.8     5.5      M    M
 17500  -17.8  -0.0   010   59   30   6.6   3.6   19.9  67.9     5.0      M    M
 17000  -16.9   1.6   010   59   31   5.6   3.1   19.3  66.7     4.5      M    M
 16500  -16.1   3.0   010   60   31   5.7   3.1   18.6  65.5     3.8      M    M
 16000  -15.3   4.5   010   60   31   5.4   2.9   17.9  64.2     3.2      M    M
 15500  -14.5   5.9   010   60   31   5.3   2.9   17.1  62.9     2.6      M    M
 15000  -13.3   8.1   010   61   31   4.8   2.7   16.0  60.8     1.6      M    M
 14500  -12.6   9.3   010   62   32   4.8   2.6   15.2  59.4     0.8      M    M
 14000  -11.8  10.8   015   62   32   5.7   3.1   14.5  58.0     0.2      M    M
 13500  -10.9  12.4   015   62   32   5.7   3.1   13.8  56.8    -0.4    656  3.3
 13000  -10.0  14.0   015   62   32   6.3   3.5   13.2  55.7    -1.0    615  3.1
 12500   -9.1  15.6   015   61   31   6.5   3.5   12.6  54.7    -1.5    570  2.9
 12000   -8.1  17.4   010   60   31   5.7   3.1   12.1  53.7    -2.0    528  2.7
 11500   -7.3  18.9   010   58   30   5.5   3.0   11.4  52.5    -2.6    488  2.5
 11000   -6.4  20.5   010   56   29   6.7   3.7   10.8  51.4    -3.2    446  2.3
 10500   -5.4  22.3   005   55   28   7.6   4.2   10.3  50.5    -3.6    401  2.0
 10250   -4.8  23.4   005   54   28   3.6   2.0   10.1  50.1    -3.9    378  1.9
 10000   -4.7  23.5   005   54   28   4.7   2.6    9.5  49.1    -4.4    366  1.9
  9750   -4.0  24.8   360   54   28  11.7   6.4    9.4  49.0    -4.5    337  1.7
  9500   -3.1  26.4   360   54   28  12.6   6.9    9.6  49.3    -4.3    303  1.5
  9250   -2.2  28.0   360   54   28   8.5   4.6    9.7  49.5    -4.2    270  1.4
  9000   -1.8  28.8   355   53   27   5.5   3.0    9.5  49.0    -4.5    249  1.3
  8750   -1.2  29.8   355   53   27   9.5   5.2    9.3  48.7    -4.7    225  1.1
  8500   -0.5  31.1   355   52   27  10.0   5.5    9.3  48.8    -4.6    194  1.0
  8250    0.2  32.4   350   51   26   7.4   4.1    9.2  48.6    -4.7    168  0.9
  8000    0.7  33.3   350   49   25   6.6   3.6    9.0  48.2    -5.0    145  0.7
  7750    1.2  34.2   345   47   24   7.4   4.1    8.8  47.8    -5.2    123  0.6
  7500    1.7  35.1   345   45   23   5.6   3.1    8.6  47.4    -5.4    100  0.5
  7250    2.0  35.6   340   42   21   3.5   1.9    8.1  46.6    -5.9     84  0.4
  7000    2.3  36.1   335   39   20   4.6   2.5    7.7  45.8    -6.4     68  0.3
  6750    2.6  36.7   330   36   19   2.3   1.2    7.3  45.1    -6.8     52  0.3
  6500    2.5  36.5   325   33   17  -2.7  -1.5    6.5  43.7    -7.6     46  0.2
  6250    2.2  36.0   320   29   15  -4.5  -2.5    5.4  41.8    -8.7     48  0.2
  6000    1.9  35.4   310   26   13  -3.3  -1.8    4.4  39.9    -9.7     50  0.3
  5750    1.7  35.1   300   22   11  -0.8  -0.5    3.5  38.3   -10.7     48  0.2
  5500    1.8  35.2   300   17    9   1.4   0.8    2.8  37.1   -11.4     39  0.2

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

           12/08/2017 at 0800 MST          |       12/08/2017 at 1100 MST
                                           |
K index... +2.3  LI... +8.4                | K index... -0.8  LI... +9.2
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 -61.2 -78.2  350  24 12  -0.6  -0.3 | -61.2 -78.2  350  19 10  -0.1  -0.0
 45000 -62.1 -79.8  345  37 19  -0.6  -0.3 | -61.3 -78.3  355  32 16  -0.0  -0.0
 40000 -61.9 -79.4  010  64 33   0.2   0.1 | -63.2 -81.8  010  61 31  -1.3  -0.7
 38000 -60.9 -77.6  015  73 37   3.4   1.9 | -62.2 -80.0  015  69 36   5.1   2.8
 36000 -58.9 -74.0  020  76 39   3.4   1.9 | -59.1 -74.4  015  73 38   5.1   2.8
 34000 -56.5 -69.7  020  78 40   9.5   5.2 | -55.7 -68.3  020  76 39   8.9   4.9
 32000 -51.2 -60.2  020  76 39   8.8   4.8 | -50.5 -58.9  015  76 39   8.6   4.7
 30000 -46.0 -50.8  020  74 38   8.0   4.4 | -44.8 -48.6  015  75 39   8.3   4.5
 29000 -43.0 -45.4  020  74 38   8.1   4.4 | -42.3 -44.1  015  73 38   8.3   4.5
 28000 -40.5 -40.9  020  73 38   8.1   4.4 | -39.9 -39.8  010  71 37   8.3   4.5
 27000 -38.1 -36.6  015  73 37   8.3   4.6 | -37.4 -35.3  010  69 36   7.9   4.3
 26000 -35.6 -32.1  020  71 36   8.4   4.6 | -35.1 -31.2  010  65 34   7.8   4.3
 25000 -33.1 -27.6  020  69 35   8.4   4.6 | -32.7 -26.9  015  62 32   7.8   4.3
 24000 -30.6 -23.1  020  66 34   7.8   4.3 | -30.4 -22.7  015  58 30   7.6   4.2
 23000 -28.5 -19.3  020  63 33   7.2   3.9 | -28.2 -18.8  015  55 28   7.5   4.1
 22000 -26.3 -15.3  015  60 31   7.2   3.9 | -25.9 -14.6  010  52 27   7.5   4.1
 21000 -24.2 -11.6  015  57 29   6.9   3.8 | -23.7 -10.7  010  50 26   7.0   3.9
 20000 -22.2  -8.0  015  57 29   6.9   3.8 | -21.6  -6.9  010  51 26   7.1   3.9
 19500 -21.2  -6.2  015  57 29   6.9   3.8 | -20.6  -5.1  010  51 26   7.1   3.9
 19000 -20.2  -4.4  015  57 29   6.9   3.8 | -19.5  -3.1  010  51 26   7.1   3.9
 18500 -19.2  -2.6  010  56 29   6.8   3.7 | -18.5  -1.3  010  51 26   7.0   3.8
 18000 -18.2  -0.8  010  57 29   6.7   3.7 | -17.5   0.5  010  52 27   7.0   3.8
 17500 -17.2   1.0  010  57 29   6.7   3.7 | -16.5   2.3  010  52 27   6.8   3.7
 17000 -16.3   2.7  010  57 29   6.4   3.5 | -15.5   4.1  010  52 27   6.1   3.3
 16500 -15.3   4.5  010  57 29   6.5   3.6 | -14.7   5.5  010  53 27   6.2   3.4
 16000 -14.4   6.1  010  58 30   5.4   3.0 | -13.8   7.2  010  53 27   5.1   2.8
 15500 -13.6   7.5  010  58 30   5.4   3.0 | -12.7   9.1  010  54 28   5.2   2.9
 15000 -12.4   9.7  010  60 31   5.4   2.9 | -11.9  10.6  010  55 28   5.3   2.9
 14500 -11.6  11.1  010  61 31   5.4   2.9 | -11.0  12.2  010  55 28   5.5   3.0
 14000 -10.7  12.7  010  61 32   5.7   3.1 | -10.3  13.5  010  55 28   4.3   2.4
 13500  -9.8  14.4  010  62 32   5.8   3.2 |  -9.5  14.9  010  54 28   4.5   2.5
 13000  -9.0  15.8  010  62 32   5.2   2.8 |  -8.8  16.2  010  53 27   4.5   2.5
 12500  -8.2  17.2  010  61 31   5.1   2.8 |  -8.2  17.2  010  52 27   4.4   2.4
 12000  -7.4  18.7  010  60 31   5.1   2.8 |  -7.4  18.7  005  51 26   5.8   3.2
 11500  -6.6  20.1  010  59 31   5.0   2.7 |  -6.5  20.3  005  51 26   5.6   3.1
 11000  -5.8  21.6  010  58 30   6.9   3.8 |  -5.5  22.1  005  50 26   8.0   4.4
 10500  -4.7  23.5  005  57 29   7.8   4.3 |  -4.4  24.1  360  49 25   8.8   4.8
 10250  -4.2  24.4  005  57 29   4.1   2.2 |  -3.8  25.2  360  48 25   4.4   2.4
 10000  -4.0  24.8  005  57 29   5.3   2.9 |  -3.6  25.5  360  48 25   5.9   3.3
  9750  -3.3  26.1  005  56 29  11.7   6.4 |  -2.8  27.0  360  47 24  12.9   7.1
  9500  -2.4  27.7  360  56 29  12.1   6.6 |  -1.8  28.8  360  46 24  12.0   6.6
  9250  -1.6  29.1  360  55 28   8.6   4.7 |  -1.0  30.2  355  45 23   8.5   4.7
  9000  -1.1  30.0  360  55 28   6.3   3.4 |  -0.5  31.1  355  45 23   6.7   3.7
  8750  -0.5  31.1  355  54 28   9.2   5.0 |   0.1  32.2  355  44 23   9.5   5.2
  8500   0.2  32.4  355  52 27   9.5   5.2 |   0.8  33.4  355  43 22   9.1   5.0
  8250   0.8  33.4  350  51 26   7.9   4.3 |   1.4  34.5  350  42 22   7.2   3.9
  8000   1.4  34.5  350  49 25   7.3   4.0 |   1.9  35.4  350  40 20   6.8   3.7
  7750   1.9  35.4  350  47 24   8.3   4.6 |   2.5  36.5  345  38 19   8.3   4.6
  7500   2.5  36.5  345  44 23   6.3   3.4 |   3.0  37.4  345  35 18   5.7   3.1
  7250   2.8  37.0  345  41 21   3.5   1.9 |   3.3  37.9  340  31 16   2.8   1.5
  7000   3.2  37.8  340  38 20   5.2   2.9 |   3.5  38.3  335  28 14   3.0   1.7
  6750   3.5  38.3  335  35 18   1.3   0.7 |   3.7  38.7  330  24 13   5.1   2.8
  6500   3.2  37.8  330  32 17  -5.6  -3.0 |   4.2  39.6  325  22 11   5.6   3.1
  6250   2.7  36.9  320  28 15  -7.1  -3.9 |   4.5  40.1  320  19 10   3.2   1.8
  6000   2.2  36.0  310  26 13  -5.8  -3.2 |   4.7  40.5  315  16  8   4.9   2.7
  5750   1.9  35.4  305  22 11  -2.6  -1.4 |   5.3  41.5  310  14  7  10.9   6.0
  5500   1.8  35.2  300  16  8   0.5   0.3 |   6.4  43.5  305  13  6  18.1   9.9

           12/08/2017 at 1400 MST          |       12/08/2017 at 1700 MST
                                           |
K index... -8.5  LI... +8.2                | K index... -18.3  LI... +7.9
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 -60.6 -77.1  330  16  8  -0.2  -0.1 | -60.6 -77.1  335  27 14  -0.5  -0.3
 45000 -60.9 -77.6  335  28 14  -0.1  -0.1 | -61.3 -78.3  335  44 22  -0.4  -0.2
 40000 -64.8 -84.6  010  60 31  -2.7  -1.5 | -66.3 -87.3  360  58 30  -3.3  -1.8
 38000 -63.6 -82.5  010  67 34   6.8   3.7 | -64.7 -84.5  360  60 31   8.4   4.6
 36000 -59.5 -75.1  005  66 34   6.8   3.7 | -59.7 -75.5  355  59 30   8.4   4.6
 34000 -55.2 -67.4  005  65 33   9.1   5.0 | -54.6 -66.3  355  58 30   8.8   4.8
 32000 -49.8 -57.6  005  65 33   9.0   4.9 | -49.4 -56.9  355  58 30   8.7   4.8
 30000 -43.9 -47.0  005  64 33   8.4   4.6 | -44.2 -47.6  360  57 29   8.1   4.4
 29000 -41.4 -42.5  005  63 32   8.4   4.6 | -41.2 -42.2  360  55 28   8.1   4.5
 28000 -38.8 -37.8  005  62 32   8.4   4.6 | -38.7 -37.7  360  54 28   8.1   4.5
 27000 -36.4 -33.5  010  60 31   7.4   4.0 | -36.4 -33.5  360  52 27   7.3   4.0
 26000 -34.2 -29.6  005  57 29   7.3   4.0 | -34.2 -29.6  360  51 26   7.3   4.0
 25000 -32.0 -25.6  005  54 28   7.3   4.0 | -32.0 -25.6  360  50 26   7.3   4.0
 24000 -29.8 -21.6  005  51 26   7.4   4.1 | -29.8 -21.6  360  48 25   7.2   3.9
 23000 -27.6 -17.7  005  50 26   7.4   4.1 | -27.7 -17.9  360  48 25   7.1   3.9
 22000 -25.4 -13.7  005  49 25   7.5   4.1 | -25.6 -14.1  360  48 24   7.1   3.9
 21000 -23.2  -9.8  005  48 25   6.7   3.7 | -23.5 -10.3  360  48 24   6.7   3.7
 20000 -21.2  -6.2  005  47 24   6.8   3.7 | -21.5  -6.7  360  49 25   6.8   3.7
 19500 -20.2  -4.4  005  47 24   6.8   3.7 | -20.5  -4.9  005  49 25   6.8   3.7
 19000 -19.2  -2.6  005  47 24   6.8   3.7 | -19.5  -3.1  005  50 26   6.8   3.7
 18500 -18.3  -0.9  005  47 24   6.4   3.5 | -18.5  -1.3  005  50 26   6.7   3.7
 18000 -17.3   0.9  005  47 24   6.4   3.5 | -17.5   0.5  005  50 26   6.7   3.7
 17500 -16.4   2.5  005  48 24   6.3   3.5 | -16.4   2.5  360  50 26   6.7   3.7
 17000 -15.5   4.1  005  48 25   6.1   3.3 | -15.4   4.3  360  50 26   6.7   3.7
 16500 -14.6   5.7  005  48 25   6.1   3.4 | -14.4   6.1  360  49 25   6.8   3.8
 16000 -13.6   7.5  005  48 25   6.0   3.3 | -13.4   7.9  360  49 25   5.8   3.2
 15500 -12.3   9.9  005  48 25   6.0   3.3 | -12.1  10.2  360  48 25   5.8   3.2
 15000 -11.4  11.5  005  49 25   5.7   3.1 | -11.3  11.7  360  47 24   5.5   3.0
 14500 -10.5  13.1  005  49 25   5.8   3.2 | -10.5  13.1  360  47 24   5.5   3.0
 14000  -9.7  14.5  005  49 25   5.3   2.9 |  -9.6  14.7  360  46 24   5.7   3.2
 13500  -8.8  16.2  005  48 25   5.3   2.9 |  -8.8  16.2  360  45 23   5.7   3.1
 13000  -8.0  17.6  005  48 25   5.9   3.2 |  -7.9  17.8  360  45 23   6.3   3.4
 12500  -7.1  19.2  360  48 25   5.8   3.2 |  -6.9  19.6  360  45 23   6.3   3.4
 12000  -6.2  20.8  360  48 25   6.4   3.5 |  -6.0  21.2  360  44 23   6.2   3.4
 11500  -5.3  22.5  360  48 25   6.3   3.5 |  -5.1  22.8  360  44 22   6.0   3.3
 11000  -4.2  24.4  355  47 24   7.4   4.1 |  -4.1  24.6  360  43 22   7.9   4.3
 10500  -3.1  26.4  355  46 24   8.3   4.6 |  -2.9  26.8  355  42 22   8.6   4.7
 10250  -2.6  27.3  350  45 23   3.9   2.1 |  -2.3  27.9  355  42 22   4.2   2.3
 10000  -2.4  27.7  350  45 23   5.2   2.9 |  -2.1  28.2  355  42 22   5.9   3.3
  9750  -1.7  28.9  350  44 23  11.2   6.1 |  -1.4  29.5  355  40 21  12.0   6.6
  9500  -0.9  30.4  350  42 22  10.0   5.5 |  -0.5  31.1  350  38 20  10.6   5.8
  9250  -0.3  31.5  350  41 21   6.9   3.8 |   0.1  32.2  350  36 19   7.2   3.9
  9000   0.1  32.2  345  38 20   5.1   2.8 |   0.5  32.9  350  33 17   5.5   3.0
  8750   0.6  33.1  345  35 18   7.6   4.1 |   1.0  33.8  345  30 15   8.0   4.4
  8500   1.1  34.0  345  31 16   7.6   4.2 |   1.6  34.9  345  26 14   7.8   4.3
  8250   1.6  34.9  345  28 14   6.7   3.7 |   2.2  36.0  340  24 12   6.7   3.7
  8000   2.1  35.8  340  25 13   6.6   3.6 |   2.6  36.7  340  22 11   6.5   3.6
  7750   2.6  36.7  335  22 11   7.3   4.0 |   3.1  37.6  335  20 11   7.7   4.2
  7500   3.2  37.8  335  19 10   8.8   4.8 |   3.7  38.7  335  20 10   7.6   4.2
  7250   3.9  39.0  335  18  9   9.4   5.2 |   4.2  39.6  330  19 10   6.7   3.7
  7000   4.6  40.3  330  17  9   9.2   5.0 |   4.7  40.5  325  19 10   7.0   3.8
  6750   5.3  41.5  330  16  8   9.6   5.3 |   5.2  41.4  325  18  9   6.4   3.5
  6500   6.0  42.8  330  16  8  10.1   5.5 |   5.7  42.3  320  18  9   6.9   3.8
  6250   6.8  44.2  330  15  8   9.9   5.4 |   6.3  43.3  320  17  8   7.6   4.2
  6000   7.5  45.5  330  15  8  10.3   5.7 |   6.8  44.2  320  15  8   7.6   4.1
  5750   8.3  46.9  330  14  7  12.0   6.6 |   7.3  45.1  315  13  7   2.2   1.2
  5500   9.3  48.7  330  13  7  13.6   7.5 |   7.0  44.6  315   9  5  -7.0  -3.8
________________________________________________________________________________

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


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