Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 191241
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0541 MST Monday, February 19, 2018

This forecast is for Monday, February 19, 2018:

If the trigger temperature of 50.6 F/10.3 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 4839 ft MSL (0 ft AGL)

Forecast maximum temperature................... 45.0 F/7.7 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. None
Thermal soaring outlook for Tuesday 02/20...... Poor

Wave Soaring Index............................. Not available

Remarks...

Sunrise/Sunset.................... 07:00:17 / 17:54:45 MST
Total possible sunshine........... 10 hr 54 min 29 sec (654 min 29 sec)
Altitude of sun at 12:27:48 MST... 39.83 degrees

Upper air data from rawinsonde observation taken on 02/19/2018 at 0500 MST

Freezing level.................. 8142 ft MSL (3303 ft AGL)
Convective condensation level... 12038 ft MSL (7199 ft AGL)
Lifted condensation level....... 10312 ft MSL (5472 ft AGL)
Lifted index.................... +4.7
K index......................... +19.0

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  -59.6 -75.3   235   88   45   4.4   2.4  104.7 220.4    55.1      M    M
 45000  -54.1 -65.4   235  115   59   4.1   2.3   87.8 190.0    48.9      M    M
 40000  -52.9 -63.2   245  102   52   0.6   0.4   66.7 152.0    38.5      M    M
 38000  -50.9 -59.6   250  105   54  -3.6  -2.0   60.7 141.2    35.6      M    M
 36000  -56.9 -70.4   240  116   60 -24.0 -13.2   43.3 109.9    24.6      M    M
 34000  -55.8 -68.4   235  115   59   7.5   4.1   36.3  97.4    20.4      M    M
 32000  -51.2 -60.2   235  112   58   0.1   0.1   33.7  92.6    19.1      M    M
 30000  -48.0 -54.4   230  108   56  -0.1  -0.1   30.1  86.1    17.0      M    M
 29000  -46.4 -51.5   230  107   55   7.3   4.0   28.2  82.7    15.8      M    M
 28000  -44.2 -47.6   230  104   53   7.3   4.0   27.0  80.7    15.1      M    M
 27000  -42.0 -43.6   225  101   52   7.3   4.0   26.1  78.9    14.6      M    M
 26000  -39.8 -39.6   225   99   51   7.3   4.0   25.2  77.4    14.1      M    M
 25000  -37.6 -35.7   225   96   49   7.3   4.0   24.5  76.1    13.7      M    M
 24000  -35.8 -32.4   230   96   49   2.1   1.2   23.1  73.5    12.7      M    M
 23000  -35.1 -31.2   235   75   39   4.7   2.6   20.3  68.6    10.6      M    M
 22000  -32.9 -27.2   230   73   37   7.4   4.1   19.3  66.7     9.9      M    M
 21000  -30.6 -23.1   235   75   39   7.4   4.1   18.5  65.3     9.4      M    M
 20000  -28.6 -19.5   235   77   40   5.8   3.2   17.6  63.6     8.7      M    M
 19500  -27.7 -17.9   235   76   39   5.9   3.3   16.8  62.3     8.2      M    M
 19000  -26.8 -16.2   235   75   39   5.9   3.3   16.1  61.1     7.6      M    M
 18500  -25.9 -14.6   235   74   38   5.9   3.3   15.5  59.9     7.1      M    M
 18000  -25.0 -13.0   235   74   38   5.8   3.2   14.8  58.7     6.6      M    M
 17500  -23.5 -10.3   240   72   37   7.2   4.0   14.1  57.3     5.9      M    M
 17000  -22.4  -8.3   240   69   36  10.7   5.9   13.8  56.9     5.7      M    M
 16500  -20.9  -5.6   240   58   30   8.7   4.7   13.9  57.0     5.7      M    M
 16000  -19.6  -3.3   235   48   25   8.9   4.9   13.8  56.8     5.6      M    M
 15500  -18.3  -0.9   230   48   25   8.9   4.9   13.6  56.5     5.5      M    M
 15000  -16.9   1.6   230   48   25   8.3   4.5   13.5  56.3     5.4      M    M
 14500  -15.9   3.4   225   48   25   6.5   3.6   13.0  55.4     5.0      M    M
 14000  -14.9   5.2   225   48   25   6.5   3.6   12.5  54.5     4.5      M    M
 13500  -13.9   7.0   225   47   24   8.5   4.7   12.0  53.7     4.1      M    M
 13000  -12.5   9.5   225   47   24   9.5   5.2   12.0  53.6     4.1      M    M
 12500  -11.1  12.0   225   46   24   9.6   5.3   12.0  53.5     4.1      M    M
 12000   -9.7  14.5   225   46   24   8.9   4.9   11.9  53.4     4.0      M    M
 11500   -8.4  16.9   225   47   24   8.9   4.9   11.8  53.2     3.9      M    M
 11000   -7.0  19.4   225   48   25   8.9   4.9   11.7  53.0     3.8      M    M
 10500   -5.7  21.7   220   46   24   8.9   4.9   11.5  52.7     3.7      M    M
 10250   -5.0  23.0   220   45   23   9.0   4.9   11.4  52.6     3.6      M    M
 10000   -4.4  24.1   220   45   23   8.9   4.9   11.4  52.5     3.6      M    M
  9750   -3.7  25.3   215   44   23   9.2   5.1   11.3  52.4     3.5      M    M
  9500   -3.1  26.4   215   43   22   8.0   4.4   11.3  52.3     3.5      M    M
  9250   -2.5  27.5   215   42   21   7.1   3.9   11.1  51.9     3.3      M    M
  9000   -2.0  28.4   215   40   21   7.6   4.2   10.9  51.6     3.1      M    M
  8750   -1.4  29.5   215   40   21   7.5   4.1   10.7  51.3     2.9      M    M
  8500   -0.9  30.4   215   40   21   7.5   4.1   10.6  51.0     2.8      M    M
  8250   -0.3  31.5   210   41   21   7.5   4.1   10.4  50.7     2.6      M    M
  8000    0.2  32.4   210   41   21   7.5   4.1   10.2  50.4     2.4      M    M
  7750    0.8  33.4   205   40   21   7.5   4.1   10.0  50.1     2.3      M    M
  7500    1.3  34.3   205   40   20   7.6   4.2    9.9  49.8     2.1      M    M
  7250    1.9  35.4   200   39   20   7.4   4.0    9.7  49.5     1.9      M    M
  7000    2.4  36.3   195   39   20   8.3   4.5    9.5  49.2     1.7      M    M
  6750    3.1  37.6   195   37   19   9.7   5.3    9.5  49.1     1.7      M    M
  6500    3.9  39.0   190   34   18   9.8   5.4    9.5  49.1     1.7      M    M
  6250    4.6  40.3   190   32   16   9.8   5.4    9.5  49.1     1.7      M    M
  6000    5.3  41.5   185   30   15   9.8   5.4    9.5  49.1     1.7      M    M
  5750    6.0  42.8   185   26   14  10.0   5.5    9.5  49.1     1.7      M    M
  5500    6.8  44.2   185   23   12   9.2   5.0    9.5  49.1     1.7      M    M
  5250    7.3  45.1   185   19   10   6.4   3.5    9.4  48.9     1.6      M    M
  5000    7.7  45.9   180   16    8   4.2   2.3    9.0  48.2     1.2      M    M

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

           02/19/2018 at 0800 MST          |       02/19/2018 at 1100 MST
                                           |
K index... +5.8  LI... -0.8                | K index... -0.6  LI... -0.1
CAPE... +75.7  CIN... -12.4                | CAPE... +159.8  CIN... -0.2
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -58.8 -73.8  250 102 53   4.2   2.3 | -58.2 -72.8  245 105 54   3.6   1.9
 45000 -52.3 -62.1  245 114 59   4.2   2.3 | -52.6 -62.7  245 120 62   3.6   2.0
 40000 -52.3 -62.1  240 112 58  -0.9  -0.5 | -52.1 -61.8  235 116 60  -0.3  -0.2
 38000 -52.8 -63.0  240 111 57  -0.5  -0.3 | -52.3 -62.1  235 113 58   0.0   0.0
 36000 -52.7 -62.9  235 113 58   0.3   0.2 | -51.9 -61.4  230 114 59   0.7   0.4
 34000 -52.5 -62.5  230 115 59   0.3   0.1 | -51.5 -60.7  230 115 59   0.7   0.4
 32000 -50.8 -59.4  230 115 59   4.0   2.2 | -50.1 -58.2  225 115 59   3.0   1.6
 30000 -48.4 -55.1  230 113 58   4.1   2.2 | -48.3 -54.9  225 114 59   3.0   1.7
 29000 -46.9 -52.4  230 112 57   6.2   3.4 | -47.1 -52.8  225 112 58   5.7   3.2
 28000 -45.0 -49.0  230 108 56   6.2   3.4 | -45.4 -49.7  225 110 57   5.6   3.1
 27000 -43.2 -45.8  230 105 54   6.2   3.4 | -43.7 -46.7  225 108 55   5.6   3.1
 26000 -41.3 -42.3  230 102 52   6.7   3.7 | -42.1 -43.8  225 105 54   6.4   3.5
 25000 -39.1 -38.4  230  98 50   7.3   4.0 | -39.8 -39.6  225 103 53   7.7   4.2
 24000 -36.9 -34.4  235  94 49   7.3   4.0 | -37.5 -35.5  225 101 52   7.7   4.2
 23000 -34.7 -30.5  235  91 47   7.1   3.9 | -35.2 -31.4  225  98 51   7.6   4.2
 22000 -32.8 -27.0  235  86 44   6.5   3.5 | -33.0 -27.4  225  95 49   7.4   4.1
 21000 -30.8 -23.4  230  81 42   6.5   3.5 | -30.7 -23.3  225  92 47   7.4   4.1
 20000 -28.9 -20.0  230  75 39   6.4   3.5 | -28.6 -19.5  225  88 45   6.6   3.6
 19500 -28.0 -18.4  230  72 37   6.3   3.5 | -27.6 -17.7  225  86 44   6.4   3.5
 19000 -27.0 -16.6  230  68 35   6.3   3.5 | -26.7 -16.1  225  83 43   6.3   3.5
 18500 -25.6 -14.1  230  63 33   6.4   3.5 | -25.7 -14.3  230  81 42   6.3   3.5
 18000 -24.6 -12.3  230  60 31   6.6   3.6 | -24.3 -11.7  230  77 40   6.3   3.5
 17500 -23.6 -10.5  225  56 29   7.7   4.3 | -23.4 -10.1  230  75 38   5.6   3.1
 17000 -22.4  -8.3  225  51 26   7.6   4.2 | -22.5  -8.5  230  72 37   5.7   3.1
 16500 -21.2  -6.2  225  47 24   8.2   4.5 | -21.7  -7.1  230  70 36   5.6   3.0
 16000 -20.0  -4.0  225  44 23   8.2   4.5 | -20.9  -5.6  230  67 34   5.5   3.0
 15500 -18.8  -1.8  225  42 21   7.8   4.3 | -20.0  -4.0  230  64 33   5.7   3.1
 15000 -17.7   0.1  225  43 22   7.5   4.1 | -19.2  -2.6  230  61 31   6.1   3.3
 14500 -16.6   2.1  230  44 23   7.5   4.1 | -18.3  -0.9  230  58 30   6.4   3.5
 14000 -15.4   4.3  230  43 22   7.8   4.3 | -17.2   1.0  230  57 29   7.7   4.2
 13500 -14.3   6.3  230  42 21   7.8   4.3 | -16.1   3.0  225  56 29   7.7   4.2
 13000 -13.2   8.2  230  45 23   7.1   3.9 | -15.0   5.0  225  56 29   7.8   4.3
 12500 -12.2  10.0  230  50 26   7.2   3.9 | -13.9   7.0  225  55 28   7.8   4.3
 12000 -11.1  12.0  230  51 26   7.6   4.2 | -12.7   9.1  225  54 28   8.4   4.6
 11500 -10.0  14.0  225  50 25   7.6   4.2 | -11.5  11.3  225  53 27   8.3   4.6
 11000  -8.8  16.2  225  49 25   9.2   5.0 | -10.3  13.5  225  52 27   9.0   5.0
 10500  -7.5  18.5  225  49 25   9.2   5.0 |  -9.0  15.8  225  50 26   8.9   4.9
 10250  -6.8  19.8  220  48 25  10.9   6.0 |  -8.3  17.1  220  49 25  10.7   5.9
 10000  -6.0  21.2  220  48 25   9.5   5.2 |  -7.5  18.5  220  48 25   9.1   5.0
  9750  -5.5  22.1  220  48 25   7.4   4.0 |  -7.0  19.4  220  47 24   6.4   3.5
  9500  -4.9  23.2  220  47 24   8.1   4.4 |  -6.5  20.3  220  46 24   7.4   4.1
  9250  -4.3  24.3  220  47 24   8.6   4.7 |  -5.9  21.4  220  45 23   9.0   4.9
  9000  -3.6  25.5  215  45 23   8.4   4.6 |  -5.2  22.6  220  43 22   9.7   5.3
  8750  -3.1  26.4  215  44 23   7.8   4.3 |  -4.5  23.9  220  42 22   9.4   5.1
  8500  -2.5  27.5  215  43 22   7.7   4.2 |  -3.8  25.2  220  41 21   8.9   4.9
  8250  -2.0  28.4  210  42 22   7.5   4.1 |  -3.2  26.2  220  40 20   8.0   4.4
  8000  -1.4  29.5  210  40 21   7.5   4.1 |  -2.6  27.3  220  38 19   8.3   4.5
  7750  -0.9  30.4  205  38 20   7.6   4.2 |  -1.9  28.6  220  36 19  10.2   5.6
  7500  -0.3  31.5  205  37 19   7.2   3.9 |  -1.2  29.8  220  35 18  10.2   5.6
  7250   0.2  32.4  205  35 18   6.7   3.7 |  -0.5  31.1  215  34 18   9.2   5.0
  7000   0.7  33.3  200  33 17   6.9   3.8 |   0.2  32.4  215  33 17   9.4   5.2
  6750   1.1  34.0  195  31 16   6.0   3.3 |   0.9  33.6  215  32 16  10.3   5.6
  6500   1.5  34.7  195  28 14   5.2   2.8 |   1.7  35.1  215  30 15  10.7   5.9
  6250   1.9  35.4  190  24 12   5.6   3.1 |   2.5  36.5  215  28 14  10.6   5.8
  6000   2.3  36.1  185  21 11   4.6   2.5 |   3.3  37.9  215  26 13   9.6   5.3
  5750   2.6  36.7  180  20 10   2.0   1.1 |   4.0  39.2  215  26 13  13.2   7.2
  5500   2.6  36.7  180  16  8   0.3   0.1 |   5.4  41.7  215  24 12  22.3  12.2
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           02/19/2018 at 1400 MST          |       02/19/2018 at 1700 MST
                                           |
K index... +18.9  LI... -1.1               | K index... +10.3  LI... -0.5
CAPE... +105.8  CIN... -0.7                | CAPE... +84.7  CIN... -4.7
                                           |
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 -58.9 -74.0  245 110 57   4.0   2.2 | -57.7 -71.9  245 106 54   3.9   2.2
 45000 -52.6 -62.7  240 118 61   4.0   2.2 | -51.6 -60.9  240 112 57   3.9   2.2
 40000 -50.7 -59.3  235 112 58   0.7   0.4 | -49.5 -57.1  235 106 55   0.9   0.5
 38000 -50.3 -58.5  235 109 56   0.9   0.5 | -48.9 -56.0  235 103 53   0.9   0.5
 36000 -49.4 -56.9  230 112 58   1.5   0.8 | -48.4 -55.1  230 106 55   0.9   0.5
 34000 -48.5 -55.3  230 116 60   1.5   0.8 | -47.8 -54.0  230 110 56   0.9   0.5
 32000 -47.3 -53.1  225 119 61   2.7   1.5 | -46.9 -52.4  230 111 57   2.2   1.2
 30000 -45.5 -49.9  225 120 62   2.7   1.5 | -45.4 -49.7  225 111 57   2.2   1.2
 29000 -44.7 -48.5  225 120 62   2.7   1.5 | -44.7 -48.5  225 110 57   2.9   1.6
 28000 -43.9 -47.0  225 119 61   2.7   1.5 | -43.8 -46.8  225 106 55   3.0   1.6
 27000 -43.1 -45.6  225 118 61   2.7   1.5 | -42.9 -45.2  225 102 53   3.0   1.6
 26000 -42.3 -44.1  225 117 60   2.4   1.3 | -42.1 -43.8  225  98 50   3.0   1.6
 25000 -40.8 -41.4  220 115 59   5.7   3.1 | -41.1 -42.0  225  93 48   3.3   1.8
 24000 -39.1 -38.4  220 113 58   5.6   3.1 | -40.1 -40.2  225  88 46   3.3   1.8
 23000 -37.4 -35.3  220 110 57   5.6   3.1 | -39.1 -38.4  220  84 43   3.2   1.8
 22000 -35.7 -32.3  220 106 55   5.9   3.2 | -37.6 -35.7  220  80 41   5.7   3.1
 21000 -33.9 -29.0  220 101 52   5.9   3.2 | -35.9 -32.6  220  76 39   5.8   3.2
 20000 -32.2 -26.0  220  96 50   6.1   3.4 | -34.2 -29.6  220  73 38   5.8   3.2
 19500 -31.2 -24.2  220  94 49   6.4   3.5 | -33.3 -27.9  220  72 37   5.9   3.2
 19000 -30.3 -22.5  220  92 47   6.5   3.6 | -32.4 -26.3  220  71 36   5.9   3.2
 18500 -29.3 -20.7  220  90 46   6.5   3.6 | -31.6 -24.9  220  69 36   5.9   3.2
 18000 -27.9 -18.2  220  86 44   6.5   3.6 | -30.2 -22.4  220  67 35   5.9   3.2
 17500 -26.8 -16.2  220  85 44   7.5   4.1 | -29.3 -20.7  220  66 34   6.2   3.4
 17000 -25.8 -14.4  220  83 43   7.4   4.1 | -28.4 -19.1  220  65 34   6.3   3.4
 16500 -24.7 -12.5  220  81 42   7.8   4.3 | -27.5 -17.5  220  64 33   6.9   3.8
 16000 -23.5 -10.3  220  79 41   8.0   4.4 | -26.4 -15.5  220  63 32   7.5   4.1
 15500 -22.3  -8.1  220  77 40   8.1   4.4 | -25.3 -13.5  220  62 32   7.8   4.3
 15000 -21.1  -6.0  220  74 38   8.3   4.6 | -24.0 -11.2  220  59 30   8.9   4.9
 14500 -19.8  -3.6  225  71 37   8.3   4.6 | -22.7  -8.9  225  56 29   8.9   4.9
 14000 -18.6  -1.5  225  68 35   8.0   4.4 | -21.4  -6.5  225  54 28   9.5   5.2
 13500 -17.4   0.7  225  65 33   8.0   4.4 | -20.0  -4.0  225  53 27   9.5   5.2
 13000 -16.2   2.8  225  62 32   8.5   4.6 | -18.6  -1.5  225  52 27   9.1   5.0
 12500 -15.0   5.0  225  58 30   8.5   4.7 | -17.2   1.0  225  50 26   9.1   5.0
 12000 -13.8   7.2  230  55 28   7.9   4.3 | -15.9   3.4  225  48 25   9.2   5.1
 11500 -12.6   9.3  230  51 26   7.8   4.3 | -14.5   5.9  230  46 24   9.3   5.1
 11000 -11.4  11.5  230  47 24   8.3   4.5 | -13.2   8.2  230  44 23   9.0   4.9
 10500 -10.2  13.6  230  43 22   7.7   4.3 | -11.9  10.6  230  42 21   8.6   4.7
 10250  -9.6  14.7  230  41 21  10.3   5.7 | -11.2  11.8  230  41 21  11.2   6.1
 10000  -8.8  16.2  230  40 20   9.8   5.4 | -10.3  13.5  235  40 21  10.6   5.8
  9750  -8.3  17.1  230  38 20   6.8   3.7 |  -9.7  14.5  235  39 20   7.7   4.2
  9500  -7.7  18.1  230  36 19   7.6   4.2 |  -9.1  15.6  235  39 20   8.5   4.7
  9250  -7.2  19.0  230  35 18   8.1   4.5 |  -8.4  16.9  235  38 20   8.9   4.9
  9000  -6.5  20.3  230  33 17   8.9   4.9 |  -7.7  18.1  235  37 19   9.5   5.2
  8750  -5.9  21.4  230  32 16   9.1   5.0 |  -7.0  19.4  235  37 19   9.9   5.4
  8500  -5.2  22.6  230  30 16   9.0   5.0 |  -6.3  20.7  235  36 19   9.6   5.3
  8250  -4.5  23.9  230  29 15   8.7   4.8 |  -5.6  21.9  235  36 18   8.7   4.8
  8000  -3.9  25.0  230  29 15   8.8   4.8 |  -4.9  23.2  235  35 18   8.7   4.8
  7750  -3.2  26.2  230  28 14  10.5   5.8 |  -4.2  24.4  240  34 17  11.0   6.0
  7500  -2.4  27.7  230  28 14  10.5   5.8 |  -3.4  25.9  240  33 17  10.7   5.9
  7250  -1.6  29.1  230  27 14   9.4   5.2 |  -2.7  27.1  240  32 17   8.9   4.9
  7000  -0.9  30.4  230  26 14   9.7   5.3 |  -2.0  28.4  240  31 16   9.4   5.1
  6750  -0.2  31.6  230  26 13  10.1   5.6 |  -1.3  29.7  240  30 16   9.6   5.3
  6500   0.6  33.1  230  25 13  10.1   5.6 |  -0.6  30.9  240  29 15   9.8   5.4
  6250   1.3  34.3  230  23 12   9.8   5.4 |   0.2  32.4  240  26 14   9.9   5.4
  6000   2.0  35.6  230  21 11   9.7   5.3 |   0.9  33.6  240  24 13   9.1   5.0
  5750   2.8  37.0  230  21 11  11.4   6.3 |   1.5  34.7  240  24 12   9.5   5.2
  5500   3.8  38.8  230  19 10  15.0   8.2 |   2.4  36.3  240  21 11  12.8   7.0
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

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 at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  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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