Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 190116
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1816 MST Sunday, February 18, 2018

This forecast is for Monday, February 19, 2018:

If the trigger temperature of 42.6 F/5.9 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 6385 ft MSL (1106 ft AGL)

Forecast maximum temperature................... 25.0 F/-4.3 C
Time of trigger temperature.................... None
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................. None
Thermal soaring outlook for Tuesday 02/20...... Poor

Wave Soaring Index............................. Fair
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 PVA
Potential height of wave....................... 14383 ft MSL (9104 ft AGL)
Wave soaring outlook for Tuesday 02/20......... Poor

Remarks... None

Sunrise/Sunset.................... 06:46:22 / 17:40:12 MST
Total possible sunshine........... 10 hr 53 min 51 sec (653 min 51 sec)
Altitude of sun at 12:13:17 MST... 39.05 degrees

Upper air data from numerical model forecast valid on 02/19/2018 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 14904 ft MSL (9625 ft AGL)
Lifted condensation level....... 6900 ft MSL (1621 ft AGL)
Lifted index.................... +18.0
K index......................... +0.4

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  -62.9 -81.2   245   57   29   3.1   1.7      M     M       M      M    M
 45000  -58.0 -72.4   240   58   30   3.1   1.7      M     M       M      M    M
 40000  -58.9 -74.0   230   52   27  -1.1  -0.6      M     M       M      M    M
 38000  -59.0 -74.2   230   49   25   5.0   2.8      M     M       M      M    M
 36000  -56.3 -69.3   225   47   24   4.5   2.5      M     M       M      M    M
 34000  -53.6 -64.5   225   45   23   4.4   2.4      M     M       M      M    M
 32000  -49.6 -57.3   225   45   23   7.3   4.0      M     M       M      M    M
 30000  -44.6 -48.3   225   44   23   7.2   4.0      M     M       M      M    M
 29000  -42.6 -44.7   225   43   22   6.9   3.8   31.0  87.8    26.5      M    M
 28000  -40.5 -40.9   230   43   22   6.9   3.8   29.9  85.8    25.9      M    M
 27000  -38.4 -37.1   230   42   22   6.9   3.8   28.9  83.9    25.4      M    M
 26000  -36.4 -33.5   230   41   21   6.8   3.7   27.8  82.0    24.9      M    M
 25000  -34.3 -29.7   230   40   21   6.8   3.7   26.6  79.9    24.3      M    M
 24000  -32.3 -26.1   235   39   20   6.8   3.7   25.5  77.9    23.7      M    M
 23000  -30.2 -22.4   235   37   19   7.4   4.1   24.5  76.2    23.2      M    M
 22000  -28.0 -18.4   235   37   19   7.3   4.0   23.6  74.4    22.7      M    M
 21000  -25.9 -14.6   235   36   18   7.3   4.0   22.8  73.0    22.2      M    M
 20000  -23.7 -10.7   230   34   17   7.1   3.9   21.9  71.4    21.7      M    M
 19500  -22.6  -8.7   230   32   17   7.1   3.9   21.4  70.5    21.4      M    M
 19000  -21.6  -6.9   230   31   16   7.1   3.9   20.9  69.6    21.1      M    M
 18500  -20.5  -4.9   225   29   15   7.1   3.9   20.5  68.8    20.9      M    M
 18000  -19.4  -2.9   225   28   14   7.0   3.9   20.1  68.1    20.7      M    M
 17500  -18.4  -1.1   225   26   13   6.7   3.7   19.5  67.2    20.3      M    M
 17000  -17.4   0.7   220   24   12   6.6   3.6   19.0  66.2    20.0      M    M
 16500  -16.4   2.5   220   22   11   7.7   4.2   18.6  65.4    19.7      M    M
 16000  -15.2   4.6   215   20   10   7.8   4.3   18.2  64.8    19.5      M    M
 15500  -14.0   6.8   210   18    9   7.2   3.9   17.9  64.3    19.3      M    M
 15000  -13.1   8.4   220   19   10   6.3   3.5   17.3  63.2    18.9      M    M
 14500  -11.7  10.9   235   21   11   4.5   2.5   16.4  61.5    18.2      M    M
 14000  -11.2  11.8   240   22   11   4.1   2.2   15.4  59.8    17.4      M    M
 13500  -10.6  12.9   245   23   12   5.2   2.9   14.5  58.1    16.6      M    M
 13000   -9.7  14.5   250   23   12   6.2   3.4   13.9  57.1    16.2      M    M
 12500   -8.8  16.2   250   23   12   6.2   3.4   13.4  56.1    15.7      M    M
 12000   -7.9  17.8   250   21   11   5.9   3.3   12.8  55.0    15.2      M    M
 11500   -7.1  19.2   250   19   10   5.4   3.0   12.2  53.9    14.6      M    M
 11000   -6.4  20.5   245   17    9   4.3   2.4   11.3  52.4    13.9      M    M
 10500   -5.8  21.6   245   15    8   2.8   1.5   10.5  50.9    13.2      M    M
 10250   -5.7  21.7   245   14    7   0.6   0.3    9.8  49.6    12.5      M    M
 10000   -5.7  21.7   245   12    6  -0.1  -0.0    9.1  48.3    11.9      M    M
  9750   -5.7  21.7   245   11    6  -0.7  -0.4    8.2  46.8    11.1      M    M
  9500   -5.9  21.4   240   10    5  -4.6  -2.5    7.3  45.2    10.3      M    M
  9250   -6.4  20.5   240    9    4  -7.7  -4.2    6.0  42.8     9.0      M    M
  9000   -6.9  19.6   240    7    4  -7.1  -3.9    4.7  40.5     7.8      M    M
  8750   -7.4  18.7   240    6    3  -4.6  -2.5    3.4  38.2     6.6      M    M
  8500   -7.6  18.3   235    5    3  -1.7  -1.0    2.5  36.5     5.7      M    M
  8250   -7.8  18.0   230    4    2  -2.1  -1.1    1.6  34.8     4.8      M    M
  8000   -7.9  17.8   215    3    2  -1.8  -1.0    0.7  33.2     4.0      M    M
  7750   -8.1  17.4   195    2    1  -2.7  -1.5   -0.2  31.6     3.1      M    M
  7500   -8.2  17.2   155    2    1  -1.4  -0.8   -1.2  29.8     2.2      M    M
  7250   -8.3  17.1   110    3    2  -0.1  -0.1   -2.0  28.5     1.5      M    M
  7000   -8.3  17.1   095    5    2   1.1   0.6   -2.7  27.1     0.7      M    M
  6750   -8.0  17.6   090    6    3   6.1   3.4   -3.2  26.3     0.3      M    M
  6500   -7.4  18.7   080    5    3   7.9   4.3   -3.3  26.0     0.1      M    M
  6250   -6.9  19.6   070    5    3   7.5   4.1   -3.5  25.7    -0.1    206  1.0
  6000   -6.3  20.7   065    5    3   8.3   4.6   -3.7  25.4    -0.2    181  0.9
  5750   -5.6  21.9   060    5    3  11.3   6.2   -3.7  25.4    -0.3    153  0.8
  5500   -4.6  23.7   060    5    2  15.4   8.4   -3.4  25.9     0.0      M    M

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

           02/19/2018 at 0800 MST          |       02/19/2018 at 1100 MST
                                           |
CAPE...     0.0    LI...       +5.8        | CAPE...     0.0    LI...       +3.7
CINH...     0.0    K Index... -21.6        | CINH...     0.0    K Index...  -7.4
                                           |
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 -62.3 -80.1  245  56 29   3.9   2.1 | -60.9 -77.6  240  57 29   4.0   2.2
 45000 -56.2 -69.2  240  59 31   3.9   2.1 | -54.9 -66.8  235  62 32   4.0   2.2
 40000 -56.9 -70.4  235  53 28  -1.2  -0.7 | -56.5 -69.7  230  57 29  -1.9  -1.1
 38000 -57.3 -71.1  230  51 26   3.7   2.0 | -57.4 -71.3  225  54 28   3.5   1.9
 36000 -55.4 -67.7  230  50 26   3.2   1.7 | -55.3 -67.5  225  54 28   3.4   1.9
 34000 -53.5 -64.3  225  49 25   3.3   1.8 | -53.3 -63.9  220  54 28   3.5   1.9
 32000 -49.4 -56.9  225  48 25   6.8   3.8 | -49.4 -56.9  220  53 27   6.5   3.6
 30000 -45.3 -49.5  225  47 24   6.9   3.8 | -45.5 -49.9  220  52 27   6.5   3.5
 29000 -43.3 -45.9  225  47 24   6.6   3.6 | -43.5 -46.3  220  51 26   6.7   3.7
 28000 -41.3 -42.3  225  46 24   6.6   3.6 | -41.5 -42.7  220  51 26   6.7   3.7
 27000 -39.4 -38.9  230  45 23   6.6   3.6 | -39.5 -39.1  220  50 26   6.7   3.7
 26000 -37.3 -35.1  230  44 23   7.3   4.0 | -37.4 -35.3  225  49 25   7.1   3.9
 25000 -35.1 -31.2  230  44 22   7.3   4.0 | -35.3 -31.5  225  48 25   7.1   3.9
 24000 -32.9 -27.2  230  43 22   7.3   4.0 | -33.2 -27.8  225  47 24   7.1   3.9
 23000 -30.8 -23.4  235  42 21   7.2   4.0 | -31.0 -23.8  225  46 24   7.3   4.0
 22000 -28.6 -19.5  235  40 20   7.2   4.0 | -28.8 -19.8  230  45 23   7.4   4.0
 21000 -26.4 -15.5  235  37 19   7.2   4.0 | -26.6 -15.9  230  44 22   7.3   4.0
 20000 -24.3 -11.7  235  35 18   6.7   3.7 | -24.5 -12.1  230  42 22   6.3   3.5
 19500 -23.3  -9.9  230  34 17   6.7   3.7 | -23.6 -10.5  230  42 22   6.4   3.5
 19000 -22.3  -8.1  230  33 17   6.7   3.7 | -22.6  -8.7  235  41 21   6.4   3.5
 18500 -21.3  -6.3  230  32 16   6.7   3.7 | -21.6  -6.9  235  41 21   6.4   3.5
 18000 -20.3  -4.5  230  30 16   6.7   3.7 | -20.7  -5.3  235  40 21   6.4   3.5
 17500 -19.4  -2.9  230  29 15   6.0   3.3 | -19.6  -3.3  235  39 20   7.3   4.0
 17000 -18.5  -1.3  230  27 14   6.0   3.3 | -18.6  -1.5  235  37 19   7.3   4.0
 16500 -17.5   0.5  230  25 13   7.3   4.0 | -17.5   0.5  235  36 18   7.4   4.1
 16000 -16.4   2.5  230  23 12   7.6   4.2 | -15.8   3.6  230  32 17   7.7   4.2
 15500 -14.6   5.7  225  21 11   7.9   4.3 | -14.8   5.4  230  31 16   4.8   2.6
 15000 -13.4   7.9  225  20 10   8.0   4.4 | -14.1   6.6  230  31 16   4.6   2.5
 14500 -12.3   9.9  225  20 10   5.9   3.3 | -13.5   7.7  230  31 16   3.9   2.2
 14000 -11.6  11.1  230  21 11   5.1   2.8 | -13.0   8.6  235  32 16   3.7   2.0
 13500 -10.8  12.6  240  23 12   4.7   2.6 | -12.5   9.5  235  32 17   5.3   2.9
 13000 -10.2  13.6  240  24 12   4.4   2.4 | -11.5  11.3  235  30 16   7.6   4.2
 12500  -9.6  14.7  245  25 13   5.1   2.8 | -10.4  13.3  230  28 15   8.1   4.5
 12000  -8.7  16.3  245  25 13   6.5   3.6 |  -9.1  15.6  230  27 14   9.2   5.0
 11500  -7.8  18.0  245  25 13   6.4   3.5 |  -7.7  18.1  230  25 13   8.9   4.9
 11000  -6.9  19.6  245  23 12   5.9   3.3 |  -6.5  20.3  225  23 12   8.2   4.5
 10500  -6.0  21.2  240  21 11   5.0   2.8 |  -5.3  22.5  225  21 11   7.5   4.1
 10250  -5.7  21.7  240  20 10   3.7   2.1 |  -4.8  23.4  220  20 10   6.6   3.6
 10000  -5.5  22.1  240  19 10   2.3   1.3 |  -4.3  24.3  220  18  9   5.3   2.9
  9750  -5.4  22.3  240  17  9   1.5   0.8 |  -4.0  24.8  220  17  9   5.5   3.0
  9500  -5.4  22.3  240  16  8  -4.2  -2.3 |  -3.7  25.3  215  15  8  -0.2  -0.1
  9250  -6.0  21.2  235  14  7  -9.2  -5.1 |  -4.0  24.8  215  14  7  -6.5  -3.5
  9000  -6.7  19.9  235  13  6  -8.3  -4.5 |  -4.5  23.9  210  12  6  -5.5  -3.0
  8750  -7.3  18.9  230  11  6  -6.1  -3.3 |  -4.9  23.2  210  11  6  -7.3  -4.0
  8500  -7.6  18.3  230  10  5  -2.1  -1.2 |  -5.5  22.1  205  10  5  -6.7  -3.7
  8250  -7.7  18.1  220   8  4  -1.6  -0.9 |  -5.9  21.4  195   9  5  -5.3  -2.9
  8000  -7.8  18.0  215   7  4  -1.3  -0.7 |  -6.4  20.5  190   9  4  -5.8  -3.2
  7750  -8.0  17.6  200   6  3  -2.8  -1.6 |  -6.8  19.8  180   8  4  -5.0  -2.7
  7500  -8.2  17.2  180   6  3  -2.0  -1.1 |  -7.1  19.2  170   8  4  -2.6  -1.4
  7250  -8.2  17.2  160   6  3  -0.1  -0.1 |  -7.2  19.0  155   7  3  -2.2  -1.2
  7000  -8.3  17.1  140   6  3  -0.1  -0.0 |  -7.4  18.7  135   6  3  -0.9  -0.5
  6750  -8.1  17.4  130   7  3   4.2   2.3 |  -7.2  19.0  125   6  3   5.8   3.2
  6500  -7.7  18.1  120   6  3   6.7   3.7 |  -6.6  20.1  120   6  3   8.8   4.8
  6250  -7.2  19.0  110   6  3   6.2   3.4 |  -6.0  21.2  110   6  3   7.6   4.2
  6000  -6.7  19.9  100   6  3   8.0   4.4 |  -5.4  22.3  105   6  3   7.9   4.3
  5750  -5.9  21.4  100   6  3  11.9   6.5 |  -4.7  23.5  105   5  3  12.3   6.8
  5500  -4.9  23.2  100   5  3  14.7   8.1 |  -3.4  25.9  100   5  3  20.3  11.2

           02/19/2018 at 1400 MST          |       02/19/2018 at 1700 MST
                                           |
CAPE...     0.0    LI...       +0.3        | CAPE...     0.0    LI...       +0.7
CINH...     0.0    K Index... +14.9        | CINH...     0.0    K Index... +18.4
                                           |
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 -59.9 -75.8  240  57 30   3.8   2.1 | -59.2 -74.6  240  56 29   4.4   2.4
 45000 -54.2 -65.6  235  63 33   3.8   2.1 | -52.5 -62.5  235  61 32   4.5   2.5
 40000 -55.5 -67.9  230  59 30  -1.7  -0.9 | -52.8 -63.0  225  60 31  -1.0  -0.5
 38000 -56.4 -69.5  225  57 29   1.8   1.0 | -53.4 -64.1  225  59 30   0.5   0.3
 36000 -54.7 -66.5  220  57 29   2.8   1.5 | -52.3 -62.1  220  59 31   1.6   0.9
 34000 -52.9 -63.2  220  57 29   2.5   1.4 | -51.4 -60.5  220  60 31   1.7   0.9
 32000 -49.2 -56.6  220  56 29   6.9   3.8 | -48.6 -55.5  220  61 31   5.6   3.1
 30000 -45.0 -49.0  220  56 29   6.9   3.8 | -45.2 -49.4  225  61 31   5.7   3.1
 29000 -43.0 -45.4  220  55 28   6.8   3.8 | -43.4 -46.1  225  61 31   6.4   3.5
 28000 -40.9 -41.6  220  55 28   6.8   3.8 | -41.4 -42.5  225  61 31   6.5   3.5
 27000 -38.9 -38.0  220  55 28   6.8   3.8 | -39.5 -39.1  225  60 31   6.5   3.5
 26000 -36.8 -34.2  220  54 28   6.0   3.3 | -37.6 -35.7  225  60 31   5.3   2.9
 25000 -35.1 -31.2  225  53 27   5.9   3.2 | -36.3 -33.3  225  59 30   4.3   2.4
 24000 -33.3 -27.9  225  53 27   5.9   3.2 | -35.0 -31.0  225  58 30   4.3   2.4
 23000 -31.6 -24.9  225  52 27   6.2   3.4 | -33.7 -28.7  230  57 29   4.5   2.5
 22000 -29.6 -21.3  230  51 26   6.4   3.5 | -32.2 -26.0  230  52 27   4.9   2.7
 21000 -27.7 -17.9  230  49 25   6.4   3.5 | -30.7 -23.3  230  46 24   5.0   2.7
 20000 -26.0 -14.8  230  48 25   4.0   2.2 | -28.5 -19.3  230  40 20   8.6   4.7
 19500 -25.3 -13.5  235  46 24   4.2   2.3 | -27.2 -17.0  230  37 19   8.5   4.7
 19000 -24.7 -12.5  235  45 23   4.3   2.3 | -26.0 -14.8  230  34 18   8.5   4.7
 18500 -24.1 -11.4  235  43 22   4.3   2.4 | -24.7 -12.5  230  32 16   8.5   4.7
 18000 -23.4 -10.1  235  41 21   4.2   2.3 | -23.4 -10.1  230  29 15   8.6   4.7
 17500 -22.2  -8.0  235  38 20   6.5   3.6 | -22.2  -8.0  225  28 15   8.8   4.8
 17000 -21.3  -6.3  230  35 18   6.3   3.4 | -20.9  -5.6  225  28 15   8.8   4.8
 16500 -20.1  -4.2  230  33 17   9.1   5.0 | -19.6  -3.3  220  28 14   8.0   4.4
 16000 -18.8  -1.8  230  31 16   8.8   4.8 | -18.4  -1.1  220  28 14   8.0   4.4
 15500 -17.5   0.5  225  29 15   9.3   5.1 | -17.2   1.0  215  28 14   8.0   4.4
 15000 -16.1   3.0  225  28 14   9.4   5.2 | -16.0   3.2  215  27 14   8.0   4.4
 14500 -14.7   5.5  225  27 14   9.4   5.2 | -14.9   5.2  210  27 14   8.1   4.4
 14000 -13.3   8.1  220  25 13   9.4   5.1 | -13.7   7.3  210  27 14   8.1   4.5
 13500 -11.9  10.6  220  24 12   9.4   5.1 | -12.5   9.5  210  26 13   8.2   4.5
 13000 -10.5  13.1  220  23 12   9.4   5.1 | -11.2  11.8  205  25 13   8.7   4.8
 12500  -9.1  15.6  220  23 12   9.3   5.1 |  -9.9  14.2  205  24 12   8.8   4.8
 12000  -7.8  18.0  220  22 11   9.1   5.0 |  -8.8  16.2  205  22 11   6.2   3.4
 11500  -6.4  20.5  215  21 11   9.0   4.9 |  -7.8  18.0  200  20 10   6.7   3.7
 11000  -5.2  22.6  215  19 10   7.3   4.0 |  -7.2  19.0  200  17  9   1.5   0.8
 10500  -4.1  24.6  210  17  9   7.1   3.9 |  -7.0  19.4  195  14  7   2.1   1.1
 10250  -3.6  25.5  210  16  8   6.9   3.8 |  -6.9  19.6  190  12  6   0.7   0.4
 10000  -3.2  26.2  205  15  8   3.9   2.1 |  -6.9  19.6  185  11  5  -0.5  -0.3
  9750  -3.1  26.4  205  14  7   1.7   0.9 |  -6.9  19.6  175   9  5  -0.2  -0.1
  9500  -2.9  26.8  200  13  6   0.3   0.1 |  -7.0  19.4  170   9  4  -0.6  -0.3
  9250  -3.1  26.4  195  11  6  -3.6  -2.0 |  -7.1  19.2  160   8  4  -1.8  -1.0
  9000  -3.5  25.7  190  11  5  -4.3  -2.4 |  -7.2  19.0  145   7  4  -2.6  -1.4
  8750  -3.8  25.2  185  10  5  -3.5  -1.9 |  -7.4  18.7  125   7  3  -1.2  -0.7
  8500  -4.1  24.6  175   9  5  -4.2  -2.3 |  -7.5  18.5  115   6  3  -3.2  -1.7
  8250  -4.5  23.9  165   9  4  -4.9  -2.7 |  -7.9  17.8  100   6  3  -6.2  -3.4
  8000  -4.8  23.4  155   8  4  -5.5  -3.0 |  -8.3  17.1  080   6  3  -7.3  -4.0
  7750  -5.1  22.8  145   8  4  -0.6  -0.3 |  -8.8  16.2  065   7  4  -3.6  -2.0
  7500  -5.0  23.0  130   8  4   1.6   0.9 |  -8.8  16.2  055   8  4  -0.0  -0.0
  7250  -5.0  23.0  115   7  3  -0.9  -0.5 |  -8.9  16.0  045   8  4  -0.4  -0.2
  7000  -5.0  23.0  100   6  3  -1.4  -0.8 |  -8.9  16.0  035   9  4  -2.0  -1.1
  6750  -5.0  23.0  080   7  3   3.2   1.8 |  -8.9  16.0  025   9  5   5.0   2.7
  6500  -4.4  24.1  070   7  3   9.9   5.5 |  -8.2  17.2  020   9  5  11.2   6.1
  6250  -3.7  25.3  065   6  3  10.1   5.6 |  -7.5  18.5  015   9  5   8.3   4.6
  6000  -2.9  26.8  065   6  3   9.6   5.3 |  -6.8  19.8  015   9  5  10.0   5.5
  5750  -2.1  28.2  060   6  3  13.8   7.6 |  -6.0  21.2  010   9  5  13.3   7.3
  5500  -0.8  30.6  055   6  3  22.3  12.2 |  -4.8  23.4  010   8  4  16.8   9.2
________________________________________________________________________________

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



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