Soaring Guidance
Issued by NWS Grand Junction, CO

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322
UXUS97 KGJT 211254
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0554 MST Wednesday, February 21, 2018

This forecast is for Wednesday, February 21, 2018:

If the trigger temperature of 31.7 F/-0.1 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 732 ft/min (3.7 m/s)
   Maximum height of thermals.................. 14270 ft MSL (9431 ft AGL)

Forecast maximum temperature................... 37.0 F/3.2 C
Time of trigger temperature.................... 1100 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8565 ft MSL (3725 ft AGL)
Thermal soaring outlook for Thursday 02/22..... Good

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

Remarks...

Sunrise/Sunset.................... 06:57:38 / 17:56:59 MST
Total possible sunshine........... 10 hr 59 min 21 sec (659 min 21 sec)
Altitude of sun at 12:27:35 MST... 40.55 degrees

Upper air data from rawinsonde observation taken on 02/21/2018 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 10914 ft MSL (6075 ft AGL)
Lifted condensation level....... 12069 ft MSL (7230 ft AGL)
Lifted index.................... +10.5
K index......................... -19.7

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  -58.0 -72.4   225   89   46  -3.3  -1.8  110.5 230.9    60.4      M    M
 45000  -52.9 -63.2   220   78   40   3.4   1.8   92.7 198.9    54.1      M    M
 40000  -52.9 -63.2   215   84   43   2.0   1.1   69.4 156.8    42.8      M    M
 38000  -52.2 -62.0   230   74   38   8.0   4.4   61.5 142.7    38.8      M    M
 36000  -56.0 -68.8   235   84   43   3.0   1.7   47.1 116.8    30.1      M    M
 34000  -55.8 -68.4   230   75   39   4.6   2.5   38.8 101.9    25.1      M    M
 32000  -55.2 -67.4   215   80   41   0.5   0.3   30.5  86.9    19.9      M    M
 30000  -52.0 -61.6   215   75   38   6.6   3.6   26.9  80.3    17.8      M    M
 29000  -49.9 -57.8   215   72   37   7.1   3.9   25.6  78.1    17.0      M    M
 28000  -47.8 -54.0   215   69   35   7.1   3.9   24.5  76.1    16.4      M    M
 27000  -45.7 -50.3   220   66   34   7.5   4.1   23.5  74.4    15.9      M    M
 26000  -43.3 -45.9   220   64   33   8.0   4.4   22.8  73.0    15.5      M    M
 25000  -40.9 -41.6   220   61   31   8.0   4.4   22.2  71.9    15.3      M    M
 24000  -38.7 -37.7   220   59   30   4.4   2.4   21.2  70.1    14.6      M    M
 23000  -37.3 -35.1   220   56   29   5.1   2.8   19.3  66.8    13.3      M    M
 22000  -35.5 -31.9   220   49   25   8.6   4.7   17.9  64.3    12.4      M    M
 21000  -33.0 -27.4   220   51   26   8.3   4.6   17.4  63.3    12.1      M    M
 20000  -30.5 -22.9   225   53   27   8.3   4.6   16.9  62.5    11.8      M    M
 19500  -29.3 -20.7   225   55   28   8.3   4.6   16.7  62.0    11.7      M    M
 19000  -28.0 -18.4   225   58   30   8.3   4.6   16.4  61.6    11.6      M    M
 18500  -26.9 -16.4   230   51   26   4.9   2.7   16.1  60.9    11.3      M    M
 18000  -26.4 -15.5   235   43   22   2.3   1.3   14.9  58.8    10.4      M    M
 17500  -26.7 -16.1   235   41   21  -0.3  -0.2   12.9  55.2     8.7      M    M
 17000  -25.7 -14.3   240   41   21   4.9   2.7   11.4  52.6     7.5      M    M
 16500  -25.4 -13.7   235   38   20  -1.5  -0.8   10.1  50.3     6.4      M    M
 16000  -25.7 -14.3   235   35   18  -3.6  -2.0    8.1  46.7     4.7      M    M
 15500  -26.2 -15.2   235   33   17   0.6   0.3    5.9  42.6     2.7      M    M
 15000  -25.9 -14.6   230   30   15   2.4   1.3    4.6  40.4     1.7      M    M
 14500  -25.6 -14.1   230   27   14   0.7   0.4    3.3  37.9     0.4      M    M
 14000  -25.5 -13.9   225   24   13   2.1   1.2    1.8  35.2    -0.9    820  4.2
 13500  -24.6 -12.3   220   20   10   8.4   4.6    1.2  34.2    -1.5    778  4.0
 13000  -23.4 -10.1   215   16    8   8.1   4.4    0.9  33.7    -1.7    727  3.7
 12500  -22.2  -8.0   215   16    8   8.2   4.5    0.6  33.2    -2.0    676  3.4
 12000  -21.1  -6.0   215   16    8   8.0   4.4    0.3  32.5    -2.4    629  3.2
 11500  -19.7  -3.5   215   16    8   9.9   5.4    0.2  32.4    -2.5    571  2.9
 11000  -18.4  -1.1   215   16    8   8.6   4.7    0.1  32.2    -2.6    517  2.6
 10500  -17.0   1.4   220   16    8   9.6   5.3    0.1  32.1    -2.7    460  2.3
 10250  -16.3   2.7   220   16    8   9.4   5.2    0.1  32.1    -2.7    431  2.2
 10000  -15.6   3.9   220   16    8   9.5   5.2    0.0  32.0    -2.8    403  2.0
  9750  -14.9   5.2   220   16    8  10.0   5.5    0.0  32.0    -2.8    374  1.9
  9500  -14.1   6.6   220   16    8  10.0   5.5    0.0  32.1    -2.8    344  1.7
  9250  -13.3   8.1   215   15    8  10.2   5.6    0.1  32.1    -2.7    314  1.6
  9000  -12.6   9.3   215   15    8   9.4   5.1    0.1  32.2    -2.7    284  1.4
  8750  -12.0  10.4   210   15    8   7.7   4.2   -0.0  32.0    -2.8    258  1.3
  8500  -11.4  11.5   205   14    7   7.3   4.0   -0.2  31.6    -3.0    235  1.2
  8250  -10.9  12.4   200   14    7   7.5   4.1   -0.4  31.3    -3.2    211  1.1
  8000  -10.3  13.5   195   14    7   7.2   4.0   -0.6  31.0    -3.4    187  1.0
  7750   -9.8  14.4   185   15    7   8.0   4.4   -0.7  30.7    -3.6    164  0.8
  7500   -9.2  15.4   175   16    8   8.5   4.7   -0.8  30.5    -3.7    137  0.7
  7250   -8.5  16.7   170   17    9  10.1   5.6   -0.9  30.4    -3.8    110  0.6
  7000   -7.9  17.8   160   19   10   4.1   2.3   -1.0  30.3    -3.9     83  0.4
  6750   -8.0  17.6   160   19   10  -5.2  -2.9   -1.8  28.7    -4.8     80  0.4
  6500   -8.3  17.1   160   18    9   0.7   0.4   -2.9  26.8    -5.8     82  0.4
  6250   -7.9  17.8   155   18    9   5.9   3.3   -3.2  26.2    -6.2     63  0.3
  6000   -7.6  18.3   155   17    9   4.5   2.5   -3.6  25.5    -6.6     45  0.2
  5750   -7.2  19.0   150   16    8   5.0   2.7   -4.0  24.8    -7.0     27  0.1
  5500   -6.8  19.8   140   14    7   4.6   2.5   -4.4  24.1    -7.4      9  0.0
  5250   -6.5  20.3   130   13    7   5.7   3.1   -4.7  23.5    -7.7      M    M
  5000   -6.1  21.0   115   12    6   1.6   0.9   -5.1  22.8    -8.1      M    M

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

           02/21/2018 at 0800 MST          |       02/21/2018 at 1100 MST
                                           |
K index... -5.0  LI... +6.3                | K index... +4.3  LI... +6.2
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 -56.4 -69.5  225  84 43   2.0   1.1 | -56.6 -69.9  225  84 43   2.2   1.2
 45000 -53.3 -63.9  225  81 42   2.1   1.1 | -53.3 -63.9  220  81 42   2.2   1.2
 40000 -53.6 -64.5  225  85 44  -0.7  -0.4 | -53.8 -64.8  225  84 43  -0.8  -0.5
 38000 -54.0 -65.2  225  87 45  -0.3  -0.2 | -54.3 -65.7  225  85 44  -0.9  -0.5
 36000 -53.9 -65.0  225  86 44   0.2   0.1 | -54.8 -66.6  225  87 45  -0.9  -0.5
 34000 -53.8 -64.8  230  84 43   0.2   0.1 | -55.4 -67.7  225  88 45  -1.0  -0.5
 32000 -52.0 -61.6  230  82 42   3.8   2.1 | -53.4 -64.1  225  86 44   4.8   2.6
 30000 -49.7 -57.5  225  81 42   3.8   2.1 | -50.5 -58.9  225  82 42   4.8   2.6
 29000 -48.7 -55.7  225  79 40   3.2   1.8 | -49.2 -56.6  225  80 41   4.2   2.3
 28000 -47.7 -53.9  225  75 39   3.2   1.8 | -47.9 -54.2  225  77 39   4.2   2.3
 27000 -46.8 -52.2  230  72 37   3.2   1.8 | -46.6 -51.9  225  74 38   4.2   2.3
 26000 -45.6 -50.1  230  68 35   7.6   4.2 | -45.2 -49.4  230  71 36   7.7   4.2
 25000 -43.1 -45.6  235  65 33   8.2   4.5 | -42.9 -45.2  230  68 35   7.6   4.2
 24000 -40.7 -41.3  235  61 32   8.2   4.5 | -40.6 -41.1  230  65 33   7.6   4.2
 23000 -38.2 -36.8  240  58 30   7.7   4.2 | -38.4 -37.1  230  62 32   7.2   3.9
 22000 -35.9 -32.6  240  56 29   7.7   4.2 | -36.2 -33.2  230  58 30   7.2   3.9
 21000 -33.6 -28.5  235  53 27   7.6   4.2 | -34.0 -29.2  230  54 28   7.2   3.9
 20000 -31.7 -25.1  235  51 26   4.5   2.5 | -32.0 -25.6  230  50 26   6.5   3.6
 19500 -31.1 -24.0  235  50 26   4.5   2.5 | -31.0 -23.8  230  49 25   6.5   3.5
 19000 -30.4 -22.7  235  48 25   4.5   2.5 | -30.1 -22.2  235  47 24   6.5   3.5
 18500 -29.7 -21.5  235  47 24   4.6   2.5 | -29.1 -20.4  235  45 23   6.5   3.6
 18000 -29.0 -20.2  235  46 24   5.6   3.1 | -28.1 -18.6  235  44 22   7.0   3.8
 17500 -27.9 -18.2  240  44 23   7.9   4.3 | -27.0 -16.6  235  42 21   7.4   4.1
 17000 -26.7 -16.1  240  42 22   7.9   4.4 | -25.9 -14.6  230  40 21   7.4   4.1
 16500 -25.7 -14.3  240  40 21   6.7   3.7 | -24.9 -12.8  230  37 19   6.5   3.5
 16000 -24.6 -12.3  245  39 20   6.9   3.8 | -23.9 -11.0  230  34 18   6.7   3.7
 15500 -23.3  -9.9  245  36 19   4.6   2.5 | -23.1  -9.6  230  32 16   4.5   2.5
 15000 -22.6  -8.7  245  34 18   4.6   2.5 | -22.0  -7.6  230  29 15   4.6   2.5
 14500 -22.1  -7.8  245  32 16   2.8   1.5 | -21.3  -6.3  235  27 14   4.6   2.5
 14000 -21.7  -7.1  240  29 15   2.9   1.6 | -20.6  -5.1  235  25 13   4.6   2.5
 13500 -21.2  -6.2  240  26 14   3.5   1.9 | -19.9  -3.8  230  24 12   4.6   2.5
 13000 -20.7  -5.3  235  24 12   3.3   1.8 | -19.3  -2.7  230  22 11   4.6   2.5
 12500 -20.0  -4.0  230  21 11   6.2   3.4 | -18.6  -1.5  230  20 11   4.6   2.5
 12000 -19.2  -2.6  225  19 10   6.0   3.3 | -18.0  -0.4  225  19 10   4.9   2.7
 11500 -18.1  -0.6  220  17  9   7.7   4.2 | -17.0   1.4  225  18  9   7.6   4.2
 11000 -17.0   1.4  215  16  8   7.6   4.2 | -15.9   3.4  220  18  9   7.4   4.1
 10500 -15.8   3.6  210  15  8   8.0   4.4 | -14.8   5.4  220  17  9   7.3   4.0
 10250 -15.2   4.6  210  15  7   9.0   5.0 | -14.2   6.4  215  16  8   8.2   4.5
 10000 -14.6   5.7  210  14  7   4.9   2.7 | -13.7   7.3  215  16  8   4.7   2.6
  9750 -14.4   6.1  205  14  7   5.8   3.2 | -13.4   7.9  215  15  8   6.4   3.5
  9500 -13.6   7.5  205  13  7  10.7   5.9 | -12.6   9.3  210  14  7  11.4   6.3
  9250 -12.9   8.8  205  13  7   9.3   5.1 | -11.9  10.6  210  13  7   9.6   5.3
  9000 -12.3   9.9  200  13  6   6.4   3.5 | -11.2  11.8  205  12  6   7.5   4.1
  8750 -11.9  10.6  200  12  6   6.3   3.5 | -10.7  12.7  205  11  6   7.4   4.1
  8500 -11.3  11.7  195  12  6   9.0   4.9 | -10.0  14.0  200  11  5   9.3   5.1
  8250 -10.6  12.9  195  11  6   7.2   4.0 |  -9.4  15.1  190  10  5   7.3   4.0
  8000 -10.2  13.6  190  11  6   6.0   3.3 |  -8.9  16.0  185   9  5   5.6   3.1
  7750  -9.7  14.5  180  11  6   5.5   3.0 |  -8.5  16.7  180   8  4   4.8   2.6
  7500  -9.3  15.3  175  11  6   4.7   2.6 |  -8.2  17.2  170   7  4   4.9   2.7
  7250  -9.0  15.8  170  11  6   3.8   2.1 |  -7.7  18.1  165   6  3   7.2   3.9
  7000  -8.8  16.2  165  11  6   3.2   1.7 |  -7.2  19.0  160   6  3   7.8   4.3
  6750  -8.5  16.7  155  11  6   4.3   2.4 |  -6.6  20.1  155   5  3   8.2   4.5
  6500  -8.2  17.2  150  11  5   2.8   1.5 |  -5.9  21.4  155   5  2   9.9   5.5
  6250  -8.1  17.4  145   9  5   1.5   0.8 |  -5.1  22.8  155   4  2  11.0   6.0
  6000  -8.0  17.6  140   8  4   0.2   0.1 |  -4.3  24.3  155   4  2   9.9   5.5
  5750  -8.0  17.6  125   6  3   1.5   0.8 |  -3.6  25.5  155   4  2  10.4   5.7
  5500  -7.7  18.1  120   6  3   5.2   2.8 |  -2.8  27.0  155   4  2  11.8   6.5
  5250  -7.4  18.7  115   5  3   2.5   1.3 |  -1.9  28.6  155   4  2  10.7   5.9
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           02/21/2018 at 1400 MST          |       02/21/2018 at 1700 MST
                                           |
K index... +2.5  LI... +4.7                | K index... +13.7  LI... +3.1
CAPE... +1.9  CIN... -1.8                  | CAPE... +1.9  CIN... -4.3
                                           |
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 -56.4 -69.5  225  84 43   1.7   1.0 | -56.3 -69.3  230  76 39   1.8   1.0
 45000 -53.6 -64.5  225  80 41   1.8   1.0 | -53.4 -64.1  230  73 38   1.8   1.0
 40000 -53.8 -64.8  230  82 42  -0.5  -0.3 | -52.9 -63.2  230  71 37   0.0   0.0
 38000 -54.1 -65.4  230  83 43  -1.0  -0.5 | -52.9 -63.2  230  70 36  -0.6  -0.3
 36000 -55.0 -67.0  225  86 45  -1.5  -0.8 | -53.9 -65.0  230  75 38  -1.6  -0.9
 34000 -56.0 -68.8  225  90 46  -1.6  -0.9 | -54.8 -66.6  230  79 41  -1.6  -0.9
 32000 -54.4 -65.9  225  92 47   4.2   2.3 | -54.2 -65.6  225  83 43   2.7   1.5
 30000 -51.9 -61.4  225  93 48   4.1   2.3 | -52.4 -62.3  225  87 45   2.7   1.5
 29000 -50.2 -58.4  225  90 47   6.5   3.6 | -51.0 -59.8  225  86 44   6.0   3.3
 28000 -48.2 -54.8  225  86 45   6.5   3.6 | -49.2 -56.6  225  83 43   6.1   3.3
 27000 -46.3 -51.3  225  83 42   6.5   3.6 | -47.4 -53.3  225  79 41   6.1   3.3
 26000 -44.3 -47.7  225  78 40   6.6   3.6 | -45.5 -49.9  225  76 39   6.7   3.7
 25000 -42.3 -44.1  225  73 38   6.6   3.6 | -43.5 -46.3  225  71 36   6.7   3.7
 24000 -40.4 -40.7  225  68 35   6.6   3.6 | -41.5 -42.7  225  66 34   6.7   3.7
 23000 -38.3 -36.9  225  63 32   7.7   4.2 | -39.4 -38.9  225  60 31   8.5   4.7
 22000 -36.0 -32.8  225  58 30   7.6   4.2 | -36.9 -34.4  225  53 27   8.5   4.6
 21000 -33.8 -28.8  225  54 28   7.6   4.2 | -34.4 -29.9  225  45 23   8.4   4.6
 20000 -31.6 -24.9  225  51 26   6.8   3.8 | -32.0 -25.6  225  43 22   7.2   4.0
 19500 -30.6 -23.1  225  50 26   6.8   3.7 | -31.0 -23.8  225  44 23   7.2   3.9
 19000 -29.6 -21.3  225  49 25   6.8   3.7 | -29.9 -21.8  225  45 23   7.2   3.9
 18500 -28.5 -19.3  225  48 25   6.8   3.8 | -28.8 -19.8  225  47 24   7.1   3.9
 18000 -27.5 -17.5  225  47 24   7.0   3.8 | -27.7 -17.9  225  48 25   6.8   3.7
 17500 -26.4 -15.5  220  46 24   7.1   3.9 | -26.8 -16.2  225  45 23   6.4   3.5
 17000 -25.4 -13.7  220  45 23   7.0   3.8 | -25.9 -14.6  225  42 22   6.3   3.4
 16500 -24.5 -12.1  220  43 22   5.3   2.9 | -25.0 -13.0  225  40 21   5.2   2.8
 16000 -23.7 -10.7  215  40 21   5.3   2.9 | -24.2 -11.6  220  39 20   5.3   2.9
 15500 -22.8  -9.0  215  38 19   6.9   3.8 | -23.4 -10.1  220  38 20   5.3   2.9
 15000 -21.2  -6.2  215  34 17   6.2   3.4 | -22.7  -8.9  215  36 19   5.2   2.9
 14500 -20.6  -5.1  210  32 16   2.7   1.5 | -21.2  -6.2  210  35 18   8.2   4.5
 14000 -20.2  -4.4  210  29 15   3.0   1.7 | -20.0  -4.0  205  35 18   8.1   4.4
 13500 -19.5  -3.1  210  27 14   5.6   3.1 | -18.7  -1.7  205  34 18   8.7   4.8
 13000 -18.8  -1.8  215  25 13   5.5   3.0 | -17.4   0.7  200  34 18   8.7   4.7
 12500 -17.7   0.1  215  23 12   8.6   4.7 | -16.2   2.8  200  32 16   8.7   4.8
 12000 -16.5   2.3  210  22 11   8.3   4.6 | -14.9   5.2  205  29 15   8.6   4.7
 11500 -15.3   4.5  210  19 10   7.4   4.1 | -13.8   7.2  200  25 13   6.8   3.7
 11000 -14.2   6.4  210  16  8   7.3   4.0 | -12.7   9.1  200  21 11   6.8   3.7
 10500 -13.2   8.2  205  13  7   6.2   3.4 | -11.8  10.8  195  17  9   5.7   3.1
 10250 -12.8   9.0  205  11  6   7.1   3.9 | -11.4  11.5  190  15  8   6.7   3.7
 10000 -12.3   9.9  200  10  5   4.2   2.3 | -11.0  12.2  185  13  7   3.1   1.7
  9750 -12.0  10.4  200   9  5   4.8   2.7 | -10.8  12.6  185  12  6   3.4   1.9
  9500 -11.5  11.3  195   8  4   8.2   4.5 | -10.4  13.3  180  11  6   7.1   3.9
  9250 -10.9  12.4  190   7  3   7.2   4.0 |  -9.9  14.2  175  10  5   6.2   3.4
  9000 -10.4  13.3  190   5  3   6.1   3.3 |  -9.5  14.9  165   9  5   4.8   2.6
  8750 -10.0  14.0  185   4  2   5.7   3.1 |  -9.1  15.6  165   8  4   4.6   2.5
  8500  -9.5  14.9  180   3  1   6.1   3.4 |  -8.7  16.3  155   6  3   5.8   3.2
  8250  -9.1  15.6  165   1  1   6.8   3.7 |  -8.3  17.1  135   4  2   5.5   3.0
  8000  -8.5  16.7  150   1  0   8.1   4.4 |  -7.9  17.8  115   3  1   5.8   3.2
  7750  -7.9  17.8  000   0  0   9.2   5.0 |  -7.4  18.7  080   2  1   6.7   3.7
  7500  -7.1  19.2  000   0  0  10.0   5.5 |  -6.9  19.6  045   2  1   7.5   4.1
  7250  -6.4  20.5  000   0  0   9.9   5.4 |  -6.3  20.7  020   2  1   8.8   4.8
  7000  -5.6  21.9  000   0  0  10.1   5.5 |  -5.6  21.9  010   2  1  10.0   5.5
  6750  -4.9  23.2  000   0  0   9.2   5.0 |  -4.8  23.4  360   2  1   9.0   5.0
  6500  -4.2  24.4  000   0  0   9.8   5.4 |  -4.2  24.4  350   2  1   9.2   5.1
  6250  -3.4  25.9  315   1  0  11.2   6.1 |  -3.5  25.7  345   2  1   9.7   5.3
  6000  -2.6  27.3  310   1  0  10.2   5.6 |  -2.7  27.1  340   2  1  10.0   5.5
  5750  -1.9  28.6  305   1  0   9.9   5.4 |  -2.0  28.4  335   2  1   8.7   4.8
  5500  -1.1  30.0  305   1  0  10.9   6.0 |  -1.5  29.3  330   2  1   6.3   3.4
  5250  -0.3  31.5  305   1  0  11.1   6.1 |  -1.0  30.2  335   2  1   6.3   3.4
  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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