Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 220131
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1831 MST Saturday, February 21, 2015

This forecast is for Sunday, February 22, 2015:

If the trigger temperature of 23.3 F/-4.9 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 5307 ft MSL (0 ft AGL)

Forecast maximum temperature................... 17.0 F/-8.8 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 Monday 02/23....... Poor

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1700 MST)......... Becoming poor by morning
Height of stable layer (12-18K ft MSL)......... 12446 ft MSL (7139 ft AGL)
Weak PVA/NVA (through 1700 MST)................ Neither
Potential height of wave....................... 14415 ft MSL (9108 ft AGL)
Wave soaring outlook for Monday 02/23.......... Poor

Remarks... None

Sunrise/Sunset.................... 06:42:46 / 17:42:21 MST
Total possible sunshine........... 10 hr 59 min 35 sec (659 min 35 sec)
Altitude of sun at 12:12:50 MST... 40.16 degrees

Upper air data from numerical model forecast valid on 02/22/2015 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 8354 ft MSL (3047 ft AGL)
Lifted condensation level....... 7331 ft MSL (2025 ft AGL)
Lifted index.................... +20.4
K index......................... -3.6

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  -55.8 -68.4   300   38   20   1.3   0.7      M     M       M      M    M
 45000  -53.7 -64.7   290   43   22   1.3   0.7      M     M       M      M    M
 40000  -53.1 -63.6   275   64   33   0.3   0.1      M     M       M      M    M
 38000  -53.0 -63.4   270   75   39  -0.7  -0.4      M     M       M      M    M
 36000  -53.4 -64.1   265   95   49  -0.7  -0.4      M     M       M      M    M
 34000  -53.9 -65.0   265  116   60  -0.6  -0.3      M     M       M      M    M
 32000  -50.8 -59.4   265  119   61   6.3   3.4      M     M       M      M    M
 30000  -47.1 -52.8   260  116   60   6.4   3.5      M     M       M      M    M
 29000  -45.5 -49.9   260  112   58   4.6   2.5   29.4  84.9    28.4      M    M
 28000  -44.2 -47.6   260  108   56   4.6   2.5   27.3  81.1    27.1      M    M
 27000  -42.8 -45.0   260  103   53   4.6   2.5   25.4  77.6    26.0      M    M
 26000  -41.2 -42.2   260   99   51   7.5   4.1   23.7  74.7    25.0      M    M
 25000  -39.0 -38.2   260   96   49   7.2   4.0   22.7  72.8    24.5      M    M
 24000  -36.9 -34.4   265   93   48   7.2   4.0   21.7  71.1    24.1      M    M
 23000  -34.8 -30.6   265   88   46   5.5   3.0   20.7  69.3    23.6      M    M
 22000  -33.1 -27.6   265   78   40   5.7   3.1   19.2  66.5    22.6      M    M
 21000  -31.4 -24.5   265   68   35   5.7   3.1   17.7  63.9    21.7      M    M
 20000  -29.8 -21.6   265   59   31   5.2   2.9   16.2  61.2    20.6      M    M
 19500  -29.0 -20.2   265   56   29   5.2   2.9   15.4  59.6    20.0      M    M
 19000  -28.2 -18.8   265   53   27   5.2   2.9   14.5  58.2    19.5      M    M
 18500  -27.4 -17.3   265   50   26   5.2   2.9   13.8  56.8    18.9      M    M
 18000  -26.7 -16.1   265   46   24   5.1   2.8   13.1  55.5    18.4      M    M
 17500  -25.9 -14.6   265   44   23   4.9   2.7   12.2  53.9    17.7      M    M
 17000  -24.9 -12.8   265   41   21   5.9   3.2   11.0  51.7    16.8      M    M
 16500  -23.9 -11.0   265   37   19   6.6   3.6   10.4  50.7    16.4      M    M
 16000  -22.9  -9.2   260   34   17   6.8   3.7    9.9  49.8    16.0      M    M
 15500  -21.8  -7.2   260   31   16   7.6   4.1    9.5  49.0    15.7      M    M
 15000  -20.7  -5.3   255   29   15   7.5   4.1    9.1  48.4    15.4      M    M
 14500  -20.2  -4.4   245   27   14   0.3   0.2    8.1  46.5    14.6      M    M
 14000  -20.0  -4.0   235   25   13   1.0   0.5    6.6  43.9    13.3      M    M
 13500  -19.9  -3.8   230   23   12   0.6   0.3    5.1  41.2    12.1      M    M
 13000  -19.8  -3.6   220   21   11   0.8   0.5    3.6  38.5    10.8      M    M
 12500  -19.8  -3.6   215   19   10  -0.9  -0.5    2.0  35.7     9.4      M    M
 12000  -19.9  -3.8   205   17    9  -0.8  -0.4    0.3  32.6     7.9      M    M
 11500  -19.9  -3.8   205   14    7   0.7   0.4   -1.2  29.8     6.5      M    M
 11000  -19.8  -3.6   205   11    6   1.2   0.7   -2.7  27.1     5.1      M    M
 10500  -19.1  -2.4   200    7    3   7.7   4.2   -3.4  25.8     4.4      M    M
 10250  -18.5  -1.3   190    4    2   8.1   4.5   -3.6  25.5     4.3      M    M
 10000  -18.0  -0.4   155    2    1   4.5   2.5   -3.8  25.2     4.1      M    M
  9750  -17.8  -0.0   130    2    1   3.9   2.2   -4.4  24.2     3.6      M    M
  9500  -17.2   1.0   105    2    1   8.6   4.7   -4.6  23.8     3.4      M    M
  9250  -16.6   2.1   090    3    2   8.5   4.6   -4.7  23.6     3.3      M    M
  9000  -16.0   3.2   080    4    2   6.4   3.5   -4.8  23.3     3.2      M    M
  8750  -15.6   3.9   085    5    3   5.6   3.1   -5.2  22.7     2.8      M    M
  8500  -15.2   4.6   085    7    3   6.9   3.8   -5.4  22.2     2.6      M    M
  8250  -14.6   5.7   090    8    4   7.2   3.9   -5.6  21.9     2.4      M    M
  8000  -14.1   6.6   095    9    5   7.2   3.9   -5.8  21.5     2.2      M    M
  7750  -13.6   7.5   100   11    5   7.9   4.4   -6.0  21.2     2.0      M    M
  7500  -12.9   8.8   105   12    6   9.0   4.9   -6.1  21.0     1.9      M    M
  7250  -12.3   9.9   105   13    6   8.6   4.7   -6.2  20.9     1.8      M    M
  7000  -11.7  10.9   105   13    6   8.2   4.5   -6.3  20.7     1.7      M    M
  6750  -11.0  12.2   105   13    7   8.5   4.7   -6.4  20.5     1.6      M    M
  6500  -10.4  13.3   100   12    6   9.3   5.1   -6.5  20.4     1.5      M    M
  6250   -9.7  14.5   100   12    6   9.7   5.3   -6.5  20.4     1.5      M    M
  6000   -9.0  15.8   100   11    6   9.5   5.2   -6.5  20.3     1.5      M    M
  5750   -8.3  17.1   100   10    5  10.4   5.7   -6.5  20.4     1.5      M    M
  5500   -7.4  18.7   095    8    4  11.9   6.5   -6.3  20.6     1.6      M    M

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

           02/22/2015 at 0800 MST          |       02/22/2015 at 1100 MST
                                           |
K index... -4.9  LI... +285.8              | K index... -7.2  LI... +287.8
CAPE... 0.0  CIN... -0.4                   | CAPE... +39.8  CIN... -1.4
                                           |
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 -55.3 -67.5  295  31 16   1.4   0.8 | -54.7 -66.5  280  24 13   1.7   1.0
 45000 -53.1 -63.6  285  36 19   1.4   0.8 | -51.9 -61.4  270  33 17   1.7   0.9
 40000 -52.5 -62.5  270  59 30   0.3   0.2 | -52.9 -63.2  265  61 32  -0.9  -0.5
 38000 -52.4 -62.3  270  70 36  -0.9  -0.5 | -53.4 -64.1  265  74 38  -0.2  -0.1
 36000 -52.9 -63.2  265  90 46  -0.8  -0.5 | -53.5 -64.3  260  94 48  -0.2  -0.1
 34000 -53.4 -64.1  265 113 58  -1.4  -0.8 | -53.6 -64.5  260 113 58  -0.3  -0.2
 32000 -50.7 -59.3  260 115 59   5.5   3.0 | -51.0 -59.8  260 114 59   5.6   3.1
 30000 -47.4 -53.3  260 113 58   5.5   3.0 | -47.3 -53.1  260 110 57   5.7   3.1
 29000 -45.8 -50.4  260 110 56   5.5   3.0 | -45.5 -49.9  260 106 55   5.8   3.2
 28000 -44.2 -47.6  260 106 55   5.5   3.0 | -43.8 -46.8  260 102 52   5.8   3.2
 27000 -42.5 -44.5  260 102 53   5.5   3.0 | -42.1 -43.8  260  98 50   5.8   3.2
 26000 -40.8 -41.4  260  98 50   6.5   3.6 | -40.2 -40.4  260  92 47   6.7   3.7
 25000 -38.9 -38.0  260  91 47   6.4   3.5 | -38.3 -36.9  260  85 44   6.7   3.7
 24000 -36.9 -34.4  260  84 43   6.4   3.5 | -36.3 -33.3  260  77 40   6.7   3.7
 23000 -34.9 -30.8  260  77 40   8.0   4.4 | -34.2 -29.6  255  70 36   7.0   3.8
 22000 -32.6 -26.7  260  71 36   7.9   4.3 | -32.2 -26.0  255  62 32   6.9   3.8
 21000 -30.2 -22.4  260  64 33   7.7   4.2 | -30.1 -22.2  250  54 28   7.0   3.8
 20000 -28.6 -19.5  260  58 30   3.3   1.8 | -28.2 -18.8  250  48 24   6.1   3.4
 19500 -28.1 -18.6  260  55 28   3.2   1.7 | -27.3 -17.1  250  45 23   6.1   3.4
 19000 -27.6 -17.7  260  51 26   3.2   1.7 | -26.4 -15.5  250  42 22   6.1   3.4
 18500 -27.1 -16.8  260  48 25   3.3   1.8 | -25.4 -13.7  250  40 20   6.1   3.4
 18000 -26.0 -14.8  255  43 22   9.6   5.3 | -24.5 -12.1  250  37 19   5.9   3.2
 17500 -24.7 -12.5  255  39 20   9.2   5.1 | -23.7 -10.7  255  35 18   5.7   3.2
 17000 -23.3  -9.9  255  35 18   8.2   4.5 | -22.8  -9.0  255  34 17   5.8   3.2
 16500 -22.2  -8.0  250  34 18   7.5   4.1 | -21.9  -7.4  255  30 16   7.0   3.8
 16000 -21.1  -6.0  250  34 17   6.8   3.8 | -20.4  -4.7  245  25 13   5.9   3.2
 15500 -20.3  -4.5  250  32 16   4.8   2.7 | -19.7  -3.5  245  25 13   4.0   2.2
 15000 -19.6  -3.3  245  30 15   4.8   2.7 | -19.1  -2.4  245  25 13   3.5   1.9
 14500 -19.3  -2.7  240  28 14  -0.5  -0.3 | -19.1  -2.4  245  23 12  -2.3  -1.2
 14000 -19.3  -2.7  235  26 13   0.3   0.2 | -19.4  -2.9  235  22 11  -1.8  -1.0
 13500 -19.5  -3.1  235  23 12  -3.9  -2.1 | -19.7  -3.5  230  21 11  -3.3  -1.8
 13000 -20.1  -4.2  225  20 10  -3.6  -2.0 | -20.2  -4.4  225  20 10  -3.2  -1.8
 12500 -20.5  -4.9  220  18  9  -2.1  -1.2 | -20.6  -5.1  225  18  9  -2.2  -1.2
 12000 -20.8  -5.4  220  16  8  -2.5  -1.4 | -20.9  -5.6  220  16  8  -2.2  -1.2
 11500 -20.7  -5.3  215  14  7   3.6   2.0 | -20.9  -5.6  215  13  7   1.5   0.8
 11000 -20.2  -4.4  215  11  6   3.2   1.8 | -20.8  -5.4  205  10  5   2.1   1.2
 10500 -19.6  -3.3  205   6  3   4.8   2.6 | -20.0  -4.0  185   7  4   6.2   3.4
 10250 -19.3  -2.7  190   2  1   5.3   2.9 | -19.6  -3.3  170   6  3   6.7   3.7
 10000 -18.9  -2.0  080   2  1   2.9   1.6 | -19.1  -2.4  150   6  3   3.7   2.0
  9750 -18.8  -1.8  080   2  1   3.5   1.9 | -19.0  -2.2  155   6  3   4.1   2.2
  9500 -18.3  -0.9  100   3  2   8.3   4.6 | -18.4  -1.1  155   8  4   9.4   4.9
  9250 -17.6   0.3  110   5  2   8.6   4.7 | -17.8  -0.0  150  10  5   8.7   4.7
  9000 -17.1   1.2  115   6  3   6.0   3.3 | -17.2   1.0  150  11  6   6.9   3.8
  8750 -16.7   1.9  110   7  4   5.7   3.1 | -16.7   1.9  150  12  6   7.5   4.1
  8500 -16.1   3.0  110   9  4   8.5   4.7 | -16.0   3.2  150  13  7  10.3   5.7
  8250 -15.5   4.1  110  10  5   8.1   4.4 | -15.2   4.6  150  14  7   9.9   5.4
  8000 -15.0   5.0  115  11  5   6.7   3.7 | -14.6   5.7  145  14  7   8.8   4.8
  7750 -14.5   5.9  120  11  6   7.3   4.0 | -13.9   7.0  140  14  7   9.4   5.1
  7500 -13.9   7.0  125  12  6   8.4   4.6 | -13.2   8.2  140  13  7   9.5   5.2
  7250 -13.2   8.2  125  13  7   9.0   4.9 | -12.5   9.5  135  13  7   9.3   5.1
  7000 -12.6   9.3  130  13  7   8.9   4.9 | -11.8  10.8  135  12  6   8.9   4.9
  6750 -11.9  10.6  130  13  7   9.3   5.1 | -11.2  11.8  130  12  6   9.9   5.4
  6500 -11.2  11.8  130  13  7   9.8   5.4 | -10.4  13.3  130  11  6  10.3   5.7
  6250 -10.5  13.1  130  12  6   9.8   5.4 |  -9.7  14.5  125  10  5   9.5   5.2
  6000  -9.8  14.4  125  11  6   9.8   5.4 |  -9.0  15.8  125  10  5  10.1   5.5
  5750  -9.0  15.8  125  10  5  10.5   5.8 |  -8.2  17.2  125   9  5  12.2   6.7
  5500  -8.2  17.2  125   8  4  12.2   6.7 |  -7.1  19.2  120   8  4  15.0   8.2

           02/22/2015 at 1400 MST          |       02/22/2015 at 1700 MST
                                           |
K index... -5.7  LI... +288.0              | K index... -5.1  LI... +289.5
CAPE... +40.0  CIN... M                    | CAPE... +3.5  CIN... -0.6
                                           |
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 -55.4 -67.7  270  28 14   2.2   1.2 | -55.3 -67.5  270  30 15   1.8   1.0
 45000 -51.9 -61.4  265  32 17   2.3   1.2 | -52.5 -62.5  255  34 17   1.9   1.0
 40000 -52.9 -63.2  265  67 35  -0.9  -0.5 | -52.4 -62.3  265  65 34  -0.1  -0.0
 38000 -53.3 -63.9  265  82 42  -0.1  -0.1 | -52.5 -62.5  265  80 41  -0.6  -0.3
 36000 -53.4 -64.1  265  98 50  -0.1  -0.1 | -52.9 -63.2  265  97 50  -0.6  -0.3
 34000 -53.5 -64.3  260 113 58  -0.3  -0.2 | -53.2 -63.8  265 115 59  -0.9  -0.5
 32000 -51.0 -59.8  260 114 59   5.1   2.8 | -50.8 -59.4  265 115 59   5.0   2.8
 30000 -47.6 -53.7  260 111 57   5.5   3.0 | -47.4 -53.3  260 112 57   5.7   3.1
 29000 -45.7 -50.3  260 107 55   6.5   3.6 | -45.4 -49.7  260 107 55   6.9   3.8
 28000 -43.7 -46.7  260 103 53   6.5   3.6 | -43.3 -45.9  260 103 53   6.9   3.8
 27000 -41.8 -43.2  260  99 51   6.6   3.6 | -41.2 -42.2  260  99 51   6.8   3.8
 26000 -39.8 -39.6  260  94 48   6.7   3.7 | -39.3 -38.7  260  94 48   6.3   3.5
 25000 -37.8 -36.0  260  86 44   6.7   3.7 | -37.4 -35.3  260  88 46   6.3   3.5
 24000 -35.8 -32.4  260  78 40   6.7   3.7 | -35.5 -31.9  260  83 43   6.3   3.5
 23000 -33.7 -28.7  255  69 36   7.9   4.3 | -33.5 -28.3  260  75 39   7.8   4.3
 22000 -31.3 -24.3  255  60 31   7.9   4.3 | -31.1 -24.0  255  64 33   7.8   4.3
 21000 -29.0 -20.2  250  51 26   7.9   4.4 | -28.8 -19.8  255  52 27   7.8   4.3
 20000 -27.0 -16.6  245  44 23   6.3   3.5 | -26.5 -15.7  255  48 24   8.1   4.4
 19500 -26.0 -14.8  245  41 21   6.3   3.4 | -25.3 -13.5  255  47 24   8.1   4.4
 19000 -25.1 -13.2  240  38 20   6.3   3.4 | -24.1 -11.4  255  47 24   8.1   4.4
 18500 -24.2 -11.6  240  35 18   6.3   3.4 | -22.9  -9.2  255  46 24   8.1   4.5
 18000 -23.2  -9.8  240  32 17   6.5   3.6 | -21.7  -7.1  255  45 23   6.9   3.8
 17500 -22.3  -8.1  240  30 16   6.6   3.6 | -20.8  -5.4  255  43 22   6.3   3.5
 17000 -21.3  -6.3  240  28 15   6.4   3.5 | -19.9  -3.8  250  41 21   6.1   3.3
 16500 -20.5  -4.9  240  27 14   4.8   2.6 | -19.1  -2.4  250  41 21   5.0   2.7
 16000 -19.7  -3.5  245  26 13   5.0   2.7 | -18.0  -0.4  245  42 22   3.5   1.9
 15500 -18.7  -1.7  245  24 12   4.1   2.3 | -17.8  -0.0  245  40 21   1.1   0.6
 15000 -18.1  -0.6  245  23 12   3.8   2.1 | -17.6   0.3  245  38 19   0.6   0.3
 14500 -17.8  -0.0  240  22 11   0.7   0.4 | -17.9  -0.2  240  33 17  -3.6  -2.0
 14000 -17.7   0.1  240  21 11   1.1   0.6 | -18.3  -0.9  240  27 14  -3.3  -1.8
 13500 -18.1  -0.6  235  20 10  -6.4  -3.5 | -18.8  -1.8  245  23 12  -2.9  -1.6
 13000 -19.0  -2.2  235  19 10  -5.8  -3.2 | -19.2  -2.6  245  19 10  -2.9  -1.6
 12500 -19.7  -3.5  230  18  9  -4.9  -2.7 | -19.7  -3.5  240  15  8  -3.8  -2.1
 12000 -20.5  -4.9  220  15  8  -4.9  -2.7 | -20.3  -4.5  230  12  6  -3.6  -2.0
 11500 -20.5  -4.9  210  13  7   3.2   1.8 | -20.1  -4.2  215  10  5   5.3   2.9
 11000 -20.2  -4.4  195  12  6   3.3   1.8 | -19.4  -2.9  195  11  6   4.6   2.5
 10500 -19.3  -2.7  185  12  6   7.1   3.9 | -18.7  -1.7  185  13  7   4.3   2.3
 10250 -18.7  -1.7  180  12  6   8.0   4.4 | -18.4  -1.1  180  14  7   5.0   2.8
 10000 -18.2  -0.8  175  12  6   3.8   2.1 | -18.1  -0.6  175  15  8   2.2   1.2
  9750 -18.1  -0.6  175  13  7   4.4   2.4 | -17.9  -0.2  175  16  8   5.5   3.0
  9500 -17.4   0.7  170  14  7  10.1   5.6 | -17.2   1.0  170  16  8  11.9   6.5
  9250 -16.7   1.9  170  15  8   9.3   5.1 | -16.3   2.7  165  17  9  10.9   6.0
  9000 -16.1   3.0  165  16  8   7.1   3.9 | -15.6   3.9  165  17  9   8.3   4.6
  8750 -15.6   3.9  160  16  8   7.4   4.1 | -15.1   4.8  160  18  9   7.9   4.3
  8500 -14.9   5.2  155  16  8  10.5   5.8 | -14.4   6.1  160  18  9  10.6   5.8
  8250 -14.2   6.4  150  16  8   9.3   5.1 | -13.6   7.5  155  18  9   8.7   4.8
  8000 -13.6   7.5  145  16  8   7.4   4.1 | -13.1   8.4  150  19 10   6.2   3.4
  7750 -13.0   8.6  140  16  8   8.8   4.8 | -12.6   9.3  150  19 10   7.6   4.2
  7500 -12.3   9.9  135  16  8  10.0   5.5 | -12.0  10.4  145  19 10   8.4   4.6
  7250 -11.6  11.1  135  16  8   9.6   5.2 | -11.4  11.5  140  19 10   7.9   4.3
  7000 -10.9  12.4  130  15  8   9.2   5.1 | -10.9  12.4  135  19 10   7.2   4.0
  6750 -10.2  13.6  125  15  8   9.7   5.3 | -10.3  13.5  130  18  9   8.6   4.7
  6500  -9.5  14.9  125  14  7   9.8   5.4 |  -9.6  14.7  125  18  9   9.5   5.2
  6250  -8.8  16.2  125  13  7   9.5   5.2 |  -9.0  15.8  125  17  9   8.8   4.8
  6000  -8.1  17.4  120  13  7   9.8   5.4 |  -8.3  17.1  120  16  8   9.0   4.9
  5750  -7.3  18.9  120  12  6  12.1   6.6 |  -7.6  18.3  115  14  7   9.8   5.4
  5500  -6.3  20.7  120  11  6  15.2   8.3 |  -6.8  19.8  115  12  6  11.3   6.2
________________________________________________________________________________

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.

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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