Soaring Guidance
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12
000
UXUS97 KGJT 281319
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0619 MST Wednesday, January 28, 2015

This forecast is for Wednesday, January 28, 2015:

If the trigger temperature of 54.6 F/12.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 6318 ft MSL (1479 ft AGL)

Forecast maximum temperature................... 49.0 F/9.9 C
Time of trigger temperature.................... None
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................. 5474 ft MSL (635 ft AGL)
Thermal soaring outlook for Thursday 01/29..... Poor

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

Remarks...

Sunrise/Sunset.................... 07:24:06 / 17:29:05 MST
Total possible sunshine........... 10 hr 4 min 59 sec (604 min 59 sec)
Altitude of sun at 12:26:58 MST... 32.81 degrees

Upper air data from rawinsonde observation taken on 01/28/2015 at 0500 MST

Freezing level.................. 9107 ft MSL (4268 ft AGL)
Convective condensation level... 11796 ft MSL (6957 ft AGL)
Lifted condensation level....... 9838 ft MSL (4999 ft AGL)
Lifted index.................... +9.2
K index......................... +8.2

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  -62.7 -80.9   230   43   22   3.1   1.7   95.8 204.4    49.2      M    M
 45000  -54.7 -66.5   260   39   20   6.5   3.6   83.3 181.9    45.3      M    M
 40000  -49.0 -56.2   235   41   21  -1.6  -0.9   69.2 156.5    39.1      M    M
 38000  -48.0 -54.4   235   43   22   5.2   2.8   61.8 143.2    35.2      M    M
 36000  -44.9 -48.8   240   46   24   3.0   1.7   57.7 135.9    33.3      M    M
 34000  -46.8 -52.2   235   64   33  -9.4  -5.1   46.6 115.9    26.3      M    M
 32000  -44.9 -48.8   240   58   30   1.6   0.9   40.2 104.4    22.4      M    M
 30000  -43.8 -46.8   245   53   27   2.2   1.2   33.7  92.7    18.1      M    M
 29000  -41.8 -43.2   245   56   29   8.1   4.5   32.5  90.6    17.5      M    M
 28000  -39.3 -38.7   245   59   30   8.9   4.9   31.9  89.5    17.2      M    M
 27000  -36.5 -33.7   240   61   32   9.4   5.2   31.7  89.1    17.3      M    M
 26000  -33.7 -28.7   240   64   33   9.6   5.3   31.6  88.9    17.4      M    M
 25000  -31.2 -24.2   240   67   34   8.0   4.4   31.1  88.1    17.2      M    M
 24000  -28.7 -19.7   245   69   36   8.2   4.5   30.6  87.0    16.9      M    M
 23000  -26.5 -15.7   245   66   34   7.4   4.0   29.7  85.5    16.5      M    M
 22000  -24.2 -11.6   245   63   32   8.0   4.4   28.9  84.1    16.1      M    M
 21000  -22.0  -7.6   250   60   31   4.4   2.4   28.2  82.7    15.6      M    M
 20000  -20.3  -4.5   250   57   29   6.2   3.4   26.7  80.0    14.5      M    M
 19500  -19.6  -3.3   255   53   27   3.0   1.6   25.8  78.5    13.9      M    M
 19000  -18.8  -1.8   255   49   25   7.9   4.4   25.0  77.0    13.2      M    M
 18500  -17.7   0.1   260   46   24   7.3   4.0   24.7  76.4    12.9      M    M
 18000  -16.6   2.1   260   44   23   7.1   3.9   24.2  75.6    12.6      M    M
 17500  -15.4   4.3   260   41   21   4.7   2.6   23.1  73.7    11.8      M    M
 17000  -14.7   5.5   265   39   20   4.5   2.5   22.2  72.0    11.1      M    M
 16500  -14.0   6.8   265   37   19   5.5   3.0   21.4  70.5    10.4      M    M
 16000  -13.1   8.4   265   35   18   6.7   3.7   20.7  69.3     9.9      M    M
 15500  -12.9   8.8   255   33   17  -0.8  -0.4   19.4  66.9     8.7      M    M
 15000  -12.6   9.3   250   30   16   2.0   1.1   18.1  64.6     7.6      M    M
 14500  -12.2  10.0   255   27   14   5.0   2.8   16.9  62.4     6.5      M    M
 14000  -11.2  11.8   260   25   13   7.0   3.8   16.4  61.6     6.1      M    M
 13500  -10.1  13.8   260   24   12   7.1   3.9   16.0  60.8     5.8      M    M
 13000   -9.1  15.6   260   22   12   7.4   4.1   15.5  60.0     5.3      M    M
 12500   -7.9  17.8   255   21   11   8.4   4.6   15.3  59.5     5.1      M    M
 12000   -6.8  19.8   255   20   10   7.3   4.0   15.0  58.9     4.8      M    M
 11500   -5.7  21.7   245   17    9   7.4   4.1   14.6  58.2     4.4      M    M
 11000   -4.6  23.7   230   16    8   9.0   5.0   14.2  57.6     4.1      M    M
 10500   -3.1  26.4   235   19   10  10.4   5.7   14.3  57.7     4.2      M    M
 10250   -2.4  27.7   235   20   10   9.0   4.9   14.3  57.8     4.2      M    M
 10000   -1.8  28.8   240   20   10   7.3   4.0   14.2  57.5     4.0      M    M
  9750   -1.2  29.8   240   19   10   7.5   4.1   14.0  57.2     3.9      M    M
  9500   -0.7  30.7   245   19   10   6.5   3.6   13.8  56.8     3.7      M    M
  9250   -0.3  31.5   245   18    9   6.2   3.4   13.5  56.3     3.4      M    M
  9000    0.2  32.4   250   18    9   7.1   3.9   13.2  55.8     3.1      M    M
  8750    0.7  33.3   245   17    9   7.5   4.1   13.1  55.5     2.9      M    M
  8500    1.2  34.2   240   17    9   7.4   4.1   12.9  55.2     2.7      M    M
  8250    1.8  35.2   235   16    8   7.3   4.0   12.7  54.9     2.6      M    M
  8000    2.3  36.1   230   16    8   7.8   4.3   12.5  54.5     2.4      M    M
  7750    2.9  37.2   230   14    7   6.0   3.3   12.3  54.2     2.2      M    M
  7500    3.1  37.6   225   11    6   3.2   1.8   11.9  53.4     1.7      M    M
  7250    3.3  37.9   220    9    5   2.8   1.5   11.4  52.5     1.2      M    M
  7000    3.5  38.3   215    6    3   3.6   2.0   10.9  51.6     0.7      M    M
  6750    3.8  38.8   210    5    3   6.4   3.5   10.5  50.9     0.3      M    M
  6500    4.5  40.1   215    4    2   8.3   4.6   10.3  50.6     0.2      M    M
  6250    5.0  41.0   220    2    1   4.5   2.5   10.1  50.3    -0.0     56  0.3
  6000    5.1  41.2   240    1    1   0.1   0.1    9.5  49.2    -0.6     45  0.2
  5750    5.3  41.5   170    1    0   5.5   3.0    8.9  48.1    -1.2     33  0.2
  5500    5.3  41.5   135    2    1 -15.8  -8.7    8.2  46.8    -1.9     25  0.1
  5250    3.4  38.1   130    4    2 -19.8 -10.8    5.5  41.9    -4.5     75  0.4
  5000    3.4  38.1   125    6    3  17.9   9.8    4.8  40.7    -5.3     67  0.3

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

           01/28/2015 at 0800 MST          |       01/28/2015 at 1100 MST
                                           |
K index... +14.0  LI... +2.9               | K index... +13.3  LI... +3.6
CAPE... +19.5  CIN... -9.7                 | CAPE... 0.0  CIN... M
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -60.7 -77.3  260  23 12   3.8   2.1 | -60.3 -76.5  255  21 11   4.2   2.3
 45000 -54.9 -66.8  235  22 11   4.2   2.3 | -54.2 -65.6  235  29 15   1.9   1.1
 40000 -48.3 -54.9  255  37 19   4.1   2.3 | -50.9 -59.6  260  37 19   2.1   1.1
 38000 -48.0 -54.4  260  43 22  -1.1  -0.6 | -50.5 -58.9  270  45 23   0.0   0.0
 36000 -48.6 -55.5  265  50 26  -1.1  -0.6 | -50.5 -58.9  275  56 29   0.0   0.0
 34000 -48.5 -55.3  265  58 30   3.8   2.1 | -49.7 -57.5  280  66 34   4.8   2.6
 32000 -46.1 -51.0  265  67 34   4.0   2.2 | -46.8 -52.2  280  72 37   4.9   2.7
 30000 -43.1 -45.6  265  73 37   7.3   4.0 | -43.4 -46.1  280  73 38   7.5   4.1
 29000 -40.9 -41.6  265  71 37   7.4   4.1 | -41.1 -42.0  280  68 35   7.6   4.1
 28000 -38.7 -37.7  265  70 36   7.4   4.1 | -38.9 -38.0  285  62 32   7.6   4.1
 27000 -36.5 -33.7  260  69 35   6.8   3.7 | -36.6 -33.9  285  57 29   7.3   4.0
 26000 -34.6 -30.3  265  63 32   6.2   3.4 | -34.5 -30.1  285  56 29   7.1   3.9
 25000 -32.8 -27.0  265  57 29   6.2   3.4 | -32.3 -26.1  285  55 28   7.1   3.9
 24000 -30.9 -23.6  270  51 26   6.6   3.6 | -30.2 -22.4  285  54 28   7.3   4.0
 23000 -28.6 -19.5  270  49 25   8.1   4.4 | -27.9 -18.2  285  52 27   7.6   4.2
 22000 -25.5 -13.9  275  46 24   8.1   4.4 | -25.1 -13.2  290  50 26   7.6   4.2
 21000 -23.2  -9.8  275  44 23   6.6   3.6 | -22.9  -9.2  290  48 25   6.7   3.7
 20000 -21.2  -6.2  280  42 22   6.7   3.7 | -20.9  -5.6  295  45 23   6.7   3.7
 19500 -20.2  -4.4  280  41 21   6.7   3.7 | -19.9  -3.8  295  43 22   6.8   3.7
 19000 -19.2  -2.6  280  40 21   7.0   3.8 | -18.9  -2.0  295  42 22   6.8   3.7
 18500 -18.3  -0.9  285  39 20   4.6   2.5 | -18.0  -0.4  295  40 21   6.1   3.3
 18000 -17.6   0.3  285  37 19   4.8   2.6 | -17.0   1.4  300  37 19   6.1   3.4
 17500 -16.9   1.6  285  35 18   4.9   2.7 | -16.1   3.0  300  35 18   5.9   3.2
 17000 -16.2   2.8  285  33 17   5.0   2.8 | -15.3   4.5  300  33 17   5.8   3.2
 16500 -15.5   4.1  285  32 16   5.1   2.8 | -14.4   6.1  300  30 16   5.6   3.1
 16000 -14.7   5.5  285  30 16   5.3   2.9 | -13.6   7.5  300  29 15   5.0   2.7
 15500 -13.9   7.0  280  29 15   5.3   2.9 | -12.9   8.8  295  27 14   5.1   2.8
 15000 -13.2   8.2  280  27 14   5.2   2.8 | -12.2  10.0  295  25 13   4.7   2.6
 14500 -12.4   9.7  280  25 13   5.1   2.8 | -11.5  11.3  295  23 12   4.7   2.6
 14000 -11.6  11.1  280  24 12   7.0   3.9 | -10.8  12.6  295  21 11   5.1   2.8
 13500 -10.5  13.1  275  22 12   7.2   3.9 | -10.1  13.8  290  20 10   5.1   2.8
 13000  -9.5  14.9  275  21 11   7.6   4.2 |  -9.3  15.3  290  18  9   6.4   3.5
 12500  -8.3  17.1  270  21 11   7.7   4.2 |  -8.4  16.9  285  17  9   6.6   3.6
 12000  -7.2  19.0  270  20 10   7.5   4.1 |  -7.4  18.7  285  16  8   7.0   3.8
 11500  -6.1  21.0  265  20 10   7.5   4.1 |  -6.3  20.7  280  16  8   7.1   3.9
 11000  -5.0  23.0  265  19 10   7.4   4.1 |  -5.3  22.5  275  16  8   7.4   4.0
 10500  -3.9  25.0  265  19 10   7.7   4.2 |  -4.2  24.4  275  16  8   7.7   4.2
 10250  -3.4  25.9  260  19 10   6.4   3.5 |  -3.7  25.3  275  16  8   6.2   3.4
 10000  -3.0  26.6  260  19 10   5.9   3.2 |  -3.3  26.1  270  16  8   5.6   3.0
  9750  -2.5  27.5  260  19 10   7.3   4.0 |  -2.8  27.0  270  16  8   7.2   4.0
  9500  -2.0  28.4  260  19 10   7.6   4.2 |  -2.3  27.9  270  15  8   7.7   4.2
  9250  -1.5  29.3  260  19 10   7.0   3.8 |  -1.7  28.9  270  15  8   6.5   3.6
  9000  -1.0  30.2  260  19 10   6.5   3.6 |  -1.3  29.7  270  15  8   5.5   3.0
  8750  -0.5  31.1  255  18  9   7.1   3.9 |  -0.9  30.4  265  15  8   6.3   3.5
  8500  -0.0  32.0  255  17  9   6.9   3.8 |  -0.4  31.3  265  14  7   6.2   3.4
  8250   0.4  32.7  255  16  8   5.4   2.9 |  -0.0  32.0  265  13  7   5.0   2.8
  8000   0.8  33.4  255  15  8   4.3   2.4 |   0.3  32.5  265  12  6   4.6   2.5
  7750   1.1  34.0  255  13  7   5.6   3.1 |   0.6  33.1  265  11  5   4.5   2.5
  7500   1.5  34.7  250  12  6   5.3   2.9 |   0.9  33.6  265   9  5   4.0   2.2
  7250   1.9  35.4  250  10  5   4.1   2.3 |   1.2  34.2  265   8  4   4.0   2.2
  7000   2.2  36.0  240   8  4   4.1   2.2 |   1.5  34.7  260   6  3   3.7   2.0
  6750   2.5  36.5  235   6  3   4.9   2.7 |   1.8  35.2  255   4  2   4.8   2.6
  6500   2.9  37.2  225   5  3   4.6   2.5 |   2.2  36.0  255   4  2   7.1   3.9
  6250   3.2  37.8  205   5  3   4.1   2.3 |   2.8  37.0  250   3  2   7.5   4.1
  6000   3.5  38.3  190   5  3   2.5   1.4 |   3.3  37.9  245   3  2   7.6   4.2
  5750   3.3  37.9  180   6  3 -12.7  -7.0 |   4.0  39.2  240   3  1  12.0   6.6
  5500   1.6  34.9  170   5  3 -31.2 -17.1 |   5.2  41.4  240   3  1  18.5  10.2
  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

           01/28/2015 at 1400 MST          |       01/28/2015 at 1700 MST
                                           |
K index... +6.2  LI... +5.2                | K index... +1.5  LI... +6.2
CAPE... 0.0  CIN... -0.4                   | CAPE... 0.0  CIN... -0.7
                                           |
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 -60.2 -76.4  250  25 13   4.5   2.5 | -59.7 -75.5  260  26 13   3.8   2.1
 45000 -53.9 -65.0  255  33 17  -0.0  -0.0 | -54.5 -66.1  270  32 16  -0.5  -0.3
 40000 -53.4 -64.1  275  47 24   0.3   0.2 | -54.6 -66.3  275  53 28  -0.1  -0.1
 38000 -53.4 -64.1  280  55 29  -0.2  -0.1 | -54.5 -66.1  280  65 33   0.4   0.2
 36000 -53.5 -64.3  280  63 32  -0.2  -0.1 | -54.3 -65.7  280  79 41   0.4   0.2
 34000 -52.3 -62.1  280  66 34   6.6   3.6 | -52.6 -62.7  280  84 43   7.7   4.2
 32000 -48.3 -54.9  280  61 31   6.7   3.7 | -47.9 -54.2  280  74 38   7.8   4.3
 30000 -44.0 -47.2  285  55 28   8.3   4.6 | -43.1 -45.6  280  64 33   8.4   4.6
 29000 -41.5 -42.7  285  51 26   8.3   4.6 | -40.6 -41.1  280  59 30   8.4   4.6
 28000 -39.0 -38.2  290  48 25   8.3   4.6 | -38.1 -36.6  280  54 28   8.4   4.6
 27000 -36.5 -33.7  290  45 23   8.5   4.6 | -35.6 -32.1  275  49 25   7.6   4.2
 26000 -33.9 -29.0  295  45 23   8.5   4.6 | -33.3 -27.9  280  43 22   7.6   4.2
 25000 -31.4 -24.5  295  44 23   8.5   4.7 | -31.0 -23.8  280  38 19   7.6   4.2
 24000 -28.9 -20.0  295  44 22   8.2   4.5 | -28.7 -19.7  280  33 17   8.4   4.6
 23000 -26.4 -15.5  300  42 22   8.1   4.5 | -26.1 -15.0  280  32 16   8.7   4.8
 22000 -24.0 -11.2  305  40 21   8.1   4.5 | -23.5 -10.3  280  31 16   8.7   4.8
 21000 -21.1  -6.0  310  39 20   6.9   3.8 | -21.0  -5.8  280  29 15   7.4   4.0
 20000 -19.1  -2.4  315  37 19   6.9   3.8 | -18.2  -0.8  290  24 12   7.5   4.1
 19500 -18.0  -0.4  315  36 18   6.9   3.8 | -17.1   1.2  295  22 11   7.5   4.1
 19000 -17.0   1.4  315  35 18   6.9   3.8 | -15.9   3.4  300  20 10   7.4   4.1
 18500 -16.0   3.2  315  33 17   6.4   3.5 | -14.8   5.4  305  19 10   7.3   4.0
 18000 -15.1   4.8  315  32 16   6.5   3.6 | -13.7   7.3  305  19 10   7.4   4.0
 17500 -14.1   6.6  315  30 16   6.1   3.3 | -12.7   9.1  310  19 10   6.6   3.6
 17000 -13.2   8.2  310  29 15   6.0   3.3 | -11.7  10.9  310  19 10   6.4   3.5
 16500 -12.3   9.9  310  28 14   5.5   3.0 | -10.8  12.6  310  19 10   5.7   3.1
 16000 -11.6  11.1  310  26 13   4.7   2.6 | -10.1  13.8  310  18  9   4.4   2.4
 15500 -10.9  12.4  310  25 13   4.7   2.6 |  -9.4  15.1  310  17  9   4.4   2.4
 15000 -10.5  13.1  305  23 12   2.4   1.3 |  -9.0  15.8  310  16  8   2.2   1.2
 14500 -10.1  13.8  305  22 11   2.6   1.4 |  -8.6  16.5  310  16  8   2.5   1.4
 14000  -9.7  14.5  300  20 10   3.7   2.0 |  -8.4  16.9  310  15  8   1.6   0.9
 13500  -9.2  15.4  300  19 10   3.5   1.9 |  -8.2  17.2  305  14  7   1.5   0.8
 13000  -8.6  16.5  295  17  9   5.6   3.1 |  -7.9  17.8  305  13  7   3.8   2.1
 12500  -7.8  18.0  295  16  8   5.7   3.1 |  -7.3  18.9  305  12  6   4.0   2.2
 12000  -6.9  19.6  295  14  7   6.8   3.7 |  -6.7  19.9  305  11  6   5.9   3.2
 11500  -5.9  21.4  295  13  7   6.9   3.8 |  -5.8  21.6  305   9  5   6.2   3.4
 11000  -4.9  23.2  295  12  6   6.9   3.8 |  -4.8  23.4  305   8  4   7.1   3.9
 10500  -3.9  25.0  290  11  6   7.1   3.9 |  -3.8  25.2  300   7  4   7.3   4.0
 10250  -3.4  25.9  290  10  5   6.0   3.3 |  -3.3  26.1  300   6  3   6.6   3.6
 10000  -3.0  26.6  290  10  5   6.0   3.3 |  -2.8  27.0  300   6  3   6.8   3.7
  9750  -2.4  27.7  285  10  5   7.7   4.2 |  -2.3  27.9  295   6  3   7.9   4.3
  9500  -1.9  28.6  285  10  5   7.8   4.3 |  -1.7  28.9  295   5  3   8.0   4.4
  9250  -1.3  29.7  285  10  5   6.6   3.6 |  -1.1  30.0  295   5  2   7.2   4.0
  9000  -0.9  30.4  280  10  5   5.7   3.2 |  -0.6  30.9  295   5  2   6.5   3.6
  8750  -0.4  31.3  280  10  5   6.6   3.6 |  -0.1  31.8  290   4  2   6.9   3.8
  8500   0.1  32.2  275  10  5   6.6   3.6 |   0.4  32.7  285   4  2   7.0   3.8
  8250   0.5  32.9  275   9  5   6.1   3.3 |   0.9  33.6  280   4  2   7.1   3.9
  8000   1.0  33.8  270   8  4   6.2   3.4 |   1.4  34.5  275   3  2   7.2   4.0
  7750   1.4  34.5  265   7  4   5.2   2.8 |   2.0  35.6  265   3  2   6.9   3.8
  7500   1.7  35.1  260   6  3   5.2   2.8 |   2.4  36.3  255   3  2   6.0   3.3
  7250   2.1  35.8  255   5  3   6.1   3.3 |   2.8  37.0  250   3  1   5.6   3.0
  7000   2.5  36.5  255   4  2   5.9   3.2 |   3.2  37.8  240   2  1   5.6   3.1
  6750   2.9  37.2  250   3  2   6.0   3.3 |   3.6  38.5  220   2  1   5.7   3.1
  6500   3.4  38.1  245   3  1   8.7   4.8 |   4.1  39.4  205   1  1   7.5   4.1
  6250   4.2  39.6  245   3  1  10.7   5.9 |   4.7  40.5  210   1  1   8.4   4.6
  6000   4.9  40.8  250   3  1  10.0   5.5 |   5.3  41.5  210   1  1   9.2   5.0
  5750   5.8  42.4  245   3  1  13.7   7.5 |   6.0  42.8  205   1  1   9.7   5.3
  5500   7.0  44.6  245   3  1  19.4  10.6 |   6.6  43.9  205   1  1   7.1   3.9
  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 0.000 sec
                   West Longitude: 108 deg 32 min 0.000 sec
                   Elevation: 4839 feet (1475 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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.