weather.gov     
National Weather Service

Soaring Guidance
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  
[Printable]
945
UXUS97 KGJT 191225
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0625 MDT Tuesday, August 19, 2014

This forecast is for Tuesday, August 19, 2014:

If the trigger temperature of 80.1 F/26.7 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 480 ft/min (2.4 m/s)
   Maximum height of thermals.................. 12733 ft MSL (7894 ft AGL)

Forecast maximum temperature................... 83.0 F/28.8 C
Time of trigger temperature.................... 1145 MDT
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................. 5215 ft MSL (376 ft AGL)
Thermal soaring outlook for Wednesday 08/20.... Good

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

Remarks...

Sunrise/Sunset.................... 06:31:02 / 20:04:55 MDT
Total possible sunshine........... 13 hr 33 min 53 sec (813 min 53 sec)
Altitude of sun at 13:17:37 MDT... 63.48 degrees

Upper air data from rawinsonde observation taken on 08/19/2014 at 0600 MDT

Freezing level.................. 15070 ft MSL (10231 ft AGL)
Convective condensation level... 14917 ft MSL (10078 ft AGL)
Lifted condensation level....... 14130 ft MSL (9290 ft AGL)
Lifted index.................... -0.1
K index......................... +28.5

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  -64.3 -83.7   265   32   16  -4.7  -2.6   88.1 190.5    34.5      M    M
 45000  -58.5 -73.3   270   41   21   6.8   3.7   72.0 161.5    27.1      M    M
 40000  -53.4 -64.1   260   52   27   5.2   2.9   57.1 134.8    19.2      M    M
 38000  -50.6 -59.1   250   42   22   2.7   1.5   52.7 126.9    16.7      M    M
 36000  -47.2 -53.0   240   41   21   8.4   4.6   49.2 120.5    14.6      M    M
 34000  -42.6 -44.7   240   32   17   7.3   4.0   47.4 117.3    13.7      M    M
 32000  -36.5 -33.7   235   22   11   9.9   5.4   46.8 116.2    13.6      M    M
 30000  -31.3 -24.3   240   24   13   8.1   4.5   46.0 114.7    13.3      M    M
 29000  -28.8 -19.8   240   28   14   8.5   4.7   45.4 113.7    13.0      M    M
 28000  -26.5 -15.7   235   32   16   6.8   3.7   44.7 112.5    12.6      M    M
 27000  -24.4 -11.9   235   35   18   8.6   4.7   43.8 110.8    12.0      M    M
 26000  -21.9  -7.4   225   35   18   8.5   4.7   43.3 109.9    11.7      M    M
 25000  -19.6  -3.3   220   35   18   6.9   3.8   42.6 108.6    11.2      M    M
 24000  -17.6   0.3   215   35   18   6.5   3.6   41.4 106.5    10.3      M    M
 23000  -15.7   3.7   210   37   19   6.5   3.6   40.2 104.4     9.4      M    M
 22000  -13.5   7.7   200   27   14   8.5   4.7   39.4 103.0     8.8      M    M
 21000  -12.7   9.1   170   19   10   1.8   1.0   36.9  98.5     6.8      M    M
 20000  -11.3  11.7   180   11    6   6.1   3.4   35.2  95.4     5.4      M    M
 19500  -10.3  13.5   170    9    5   8.3   4.5   34.7  94.5     5.0      M    M
 19000   -9.1  15.6   160    9    4   8.0   4.4   34.5  94.1     4.7      M    M
 18500   -7.9  17.8   160    7    3   8.3   4.6   34.2  93.5     4.4      M    M
 18000   -6.6  20.1   160    4    2   8.8   4.8   34.0  93.2     4.4      M    M
 17500   -5.3  22.5   160    5    3   8.8   4.8   33.8  92.9     4.3      M    M
 17000   -3.4  25.9   165    7    3   7.9   4.4   33.5  92.4     4.0      M    M
 16500   -2.3  27.9   165    8    4   7.0   3.9   33.1  91.7     3.6      M    M
 16000   -1.3  29.7   165   10    5   6.6   3.6   32.7  90.9     3.2      M    M
 15500   -0.5  31.1   165   14    7   4.9   2.7   32.0  89.6     2.5      M    M
 15000    0.3  32.5   165   17    9   8.0   4.4   31.4  88.5     1.9      M    M
 14500    1.5  34.7   160   16    8   8.2   4.5   31.1  88.0     1.7      M    M
 14000    2.7  36.9   160   15    8   6.6   3.6   30.8  87.4     1.3      M    M
 13500    3.6  38.5   165   11    6   6.4   3.5   30.2  86.4     0.8      M    M
 13000    4.5  40.1   165    8    4   6.5   3.6   29.7  85.4     0.2      M    M
 12500    5.4  41.7   175    5    3   7.5   4.1   29.2  84.5    -0.3    656  3.3
 12000    6.6  43.9   200    3    2   8.4   4.6   29.0  84.1    -0.5    604  3.1
 11500    7.9  46.2   205    4    2   8.5   4.6   28.7  83.7    -0.7    552  2.8
 11000    9.1  48.4   205    4    2   8.5   4.7   28.5  83.3    -1.0    500  2.5
 10500   10.4  50.7   210    5    2   8.5   4.7   28.3  83.0    -1.2    448  2.3
 10250   11.0  51.8   210    5    3   8.8   4.8   28.2  82.8    -1.2    421  2.1
 10000   11.7  53.1   205    5    3   9.0   4.9   28.2  82.7    -1.3    394  2.0
  9750   12.3  54.1   200    6    3   9.0   4.9   28.1  82.6    -1.4    367  1.9
  9500   13.0  55.4   195    6    3   9.0   4.9   28.1  82.6    -1.4    340  1.7
  9250   13.7  56.7   195    7    3   9.0   4.9   28.0  82.5    -1.5    312  1.6
  9000   14.3  57.7   190    7    4   9.0   4.9   28.0  82.4    -1.5    285  1.4
  8750   15.0  59.0   205    7    4   9.0   4.9   27.9  82.3    -1.6    258  1.3
  8500   15.7  60.3   225    8    4   9.0   4.9   27.9  82.2    -1.6    230  1.2
  8250   16.3  61.3   235    9    5   9.0   4.9   27.8  82.1    -1.7    203  1.0
  8000   17.0  62.6   245   11    6   9.0   4.9   27.8  82.0    -1.8    176  0.9
  7750   17.7  63.9   250   11    6   9.0   4.9   27.7  81.9    -1.8    149  0.8
  7500   18.3  64.9   255   12    6   9.0   4.9   27.7  81.8    -1.9    121  0.6
  7250   19.0  66.2   265   12    6   9.0   4.9   27.6  81.7    -2.0     94  0.5
  7000   19.6  67.3   270   13    7   9.0   4.9   27.5  81.6    -2.0     67  0.3
  6750   20.3  68.5   270   13    7   9.0   4.9   27.5  81.4    -2.1     39  0.2
  6500   21.0  69.8   270   13    7   9.0   4.9   27.4  81.3    -2.2     12  0.1
  6250   21.6  70.9   270   13    7   9.0   4.9   27.3  81.2    -2.3      M    M
  6000   22.3  72.1   270   13    7   9.0   5.0   27.3  81.1    -2.4      M    M
  5750   23.0  73.4   270   11    6   8.8   4.8   27.2  81.0    -2.4      M    M
  5500   23.6  74.5   275    9    5   6.7   3.7   27.1  80.7    -2.6      M    M
  5250   24.0  75.2   280    7    4   6.4   3.5   26.8  80.2    -2.9      M    M
  5000   24.5  76.1   290    5    3   3.9   2.1   26.5  79.7    -3.1      M    M

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

           08/19/2014 at 0900 MDT          |       08/19/2014 at 1200 MDT
                                           |
K index... +29.4  LI... -0.2               | K index... +27.3  LI... -1.6
CAPE... +36.0  CIN... -18.0                | CAPE... +144.9  CIN... -43.6
                                           |
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 -64.1 -83.4  275  30 15   0.8   0.4 | -64.5 -84.1  265  34 17   0.6   0.3
 45000 -61.1 -78.0  275  44 23   5.7   3.1 | -61.5 -78.7  265  52 27   6.0   3.3
 40000 -52.2 -62.0  265  51 26   5.5   3.0 | -52.0 -61.6  265  57 29   6.0   3.3
 38000 -48.9 -56.0  260  44 23   5.4   3.0 | -48.4 -55.1  265  53 27   6.0   3.3
 36000 -45.7 -50.3  255  38 19   5.4   2.9 | -44.8 -48.6  265  49 25   5.9   3.2
 34000 -41.1 -42.0  245  33 17   8.2   4.5 | -40.1 -40.2  260  43 22   8.4   4.6
 32000 -36.1 -33.0  235  30 15   8.3   4.5 | -35.0 -31.0  250  36 19   8.4   4.6
 30000 -31.3 -24.3  235  27 14   8.0   4.4 | -30.3 -22.5  245  32 17   7.8   4.3
 29000 -28.3 -18.9  235  25 13   8.0   4.4 | -27.3 -17.1  240  30 16   7.8   4.3
 28000 -26.0 -14.8  235  24 12   7.7   4.2 | -25.0 -13.0  235  29 15   7.4   4.1
 27000 -23.7 -10.7  235  23 12   7.5   4.1 | -22.9  -9.2  240  29 15   7.1   3.9
 26000 -21.5  -6.7  235  22 11   7.5   4.1 | -20.8  -5.4  240  29 15   7.2   3.9
 25000 -19.3  -2.7  235  21 11   7.6   4.1 | -18.7  -1.7  240  28 15   7.3   4.0
 24000 -17.1   1.2  235  22 11   7.5   4.1 | -16.8   1.8  240  29 15   6.7   3.7
 23000 -15.0   5.0  230  23 12   7.5   4.1 | -14.8   5.4  240  29 15   6.7   3.7
 22000 -12.8   9.0  230  25 13   7.5   4.1 | -12.8   9.0  240  30 15   6.8   3.7
 21000 -10.9  12.4  225  28 14   6.3   3.5 | -11.1  12.0  240  31 16   6.0   3.3
 20000  -9.1  15.6  220  31 16   6.4   3.5 |  -9.3  15.3  235  33 17   6.0   3.3
 19500  -8.1  17.4  220  33 17   6.4   3.5 |  -8.4  16.9  235  34 17   6.0   3.3
 19000  -7.2  19.0  220  34 18   5.5   3.0 |  -7.6  18.3  230  35 18   5.8   3.2
 18500  -6.5  20.3  215  35 18   5.2   2.9 |  -6.7  19.9  230  36 19   5.7   3.1
 18000  -5.7  21.7  210  35 18   5.2   2.9 |  -5.9  21.4  225  38 19   5.7   3.1
 17500  -5.0  23.0  210  35 18   5.1   2.8 |  -5.1  22.8  225  38 20   5.8   3.2
 17000  -4.3  24.3  210  34 18   5.1   2.8 |  -4.2  24.4  225  38 20   5.8   3.2
 16500  -3.5  25.7  205  34 17   5.5   3.0 |  -3.4  25.9  225  38 20   5.8   3.2
 16000  -2.7  27.1  205  33 17   5.6   3.1 |  -2.5  27.5  220  37 19   5.8   3.2
 15500  -1.9  28.6  200  32 17   5.5   3.0 |  -1.7  28.9  220  36 18   5.9   3.3
 15000  -1.2  29.8  200  31 16   5.0   2.7 |  -0.8  30.6  220  34 18   6.3   3.5
 14500  -0.5  31.1  195  30 15   5.0   2.7 |   0.1  32.2  215  33 17   6.3   3.4
 14000   0.8  33.4  195  28 14   6.1   3.4 |   1.6  34.9  210  30 15   6.9   3.8
 13500   1.6  34.9  195  27 14   6.2   3.4 |   2.5  36.5  205  28 14   7.3   4.0
 13000   2.5  36.5  190  25 13   6.3   3.5 |   3.7  38.7  205  27 14   7.9   4.3
 12500   3.4  38.1  185  23 12   6.3   3.4 |   4.8  40.6  200  26 13   7.8   4.3
 12000   4.3  39.7  185  22 11   6.0   3.3 |   5.9  42.6  195  24 12   7.3   4.0
 11500   5.2  41.4  180  20 10   6.2   3.4 |   6.9  44.4  195  23 12   7.2   4.0
 11000   6.2  43.2  175  19 10   6.7   3.7 |   7.9  46.2  195  21 11   6.3   3.5
 10500   7.2  45.0  170  18  9   3.1   1.7 |   8.8  47.8  200  19 10   3.5   1.9
 10250   7.3  45.1  170  17  9   4.1   2.2 |   9.0  48.2  200  18  9   3.5   1.9
 10000   7.9  46.2  170  17  9   9.5   5.2 |   9.4  48.9  200  16  8   7.4   4.0
  9750   8.5  47.3  170  16  8   8.4   4.6 |   9.9  49.8  200  15  8   6.4   3.5
  9500   9.1  48.4  170  16  8   7.5   4.1 |  10.3  50.5  205  14  7   6.4   3.5
  9250   9.6  49.3  170  15  8   5.8   3.2 |  10.7  51.3  205  12  6   5.4   3.0
  9000  10.1  50.2  170  14  7   7.0   3.9 |  11.1  52.0  210  11  6   5.2   2.8
  8750  10.6  51.1  175  14  7   8.1   4.4 |  11.5  52.7  215  10  5   5.4   3.0
  8500  11.2  52.2  175  13  7   7.3   4.0 |  11.8  53.2  220   9  4   4.9   2.7
  8250  11.7  53.1  180  12  6   6.5   3.6 |  12.1  53.8  230   7  4   4.0   2.2
  8000  12.2  54.0  185  11  6   6.8   3.7 |  12.4  54.3  240   7  3   4.2   2.3
  7750  12.7  54.9  190  10  5   7.1   3.9 |  12.7  54.9  255   6  3   4.0   2.2
  7500  13.2  55.8  195   9  5   7.3   4.0 |  13.0  55.4  275   5  3   5.4   2.9
  7250  13.7  56.7  200   8  4   7.6   4.2 |  13.4  56.1  290   5  2   6.6   3.6
  7000  14.3  57.7  210   8  4   7.2   4.0 |  13.8  56.8  310   4  2   7.0   3.9
  6750  14.8  58.6  220   7  4   7.3   4.0 |  14.3  57.7  320   4  2   9.1   5.0
  6500  15.3  59.5  225   7  4   8.1   4.4 |  15.0  59.0  330   5  2  10.6   5.8
  6250  15.9  60.6  230   6  3   8.5   4.7 |  15.9  60.6  330   5  2  11.7   6.4
  6000  16.4  61.5  235   6  3   7.9   4.3 |  16.7  62.1  330   5  2   9.6   5.3
  5750  16.9  62.4  245   5  3   7.4   4.1 |  17.4  63.3  330   4  2  11.4   6.3
  5500  17.4  63.3  245   5  3   7.7   4.2 |  18.4  65.1  330   4  2  15.8   8.6
  5250  17.9  64.2  245   5  3   7.5   4.1 |  19.5  67.1  330   4  2  13.3   7.3
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           08/19/2014 at 1500 MDT          |       08/19/2014 at 1800 MDT
                                           |
K index... +29.0  LI... -1.7               | K index... +32.0  LI... -1.5
CAPE... +234.2  CIN... -30.3               | CAPE... +125.1  CIN... -41.7
                                           |
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 -63.6 -82.5  265  26 13   1.2   0.6 | -64.5 -84.1  270  33 17   1.4   0.7
 45000 -60.4 -76.7  265  48 25   4.1   2.2 | -61.2 -78.2  265  56 29   3.8   2.1
 40000 -53.7 -64.7  260  65 34   7.5   4.1 | -54.7 -66.5  245  57 29   8.9   4.9
 38000 -49.1 -56.4  255  57 30   7.6   4.2 | -49.2 -56.6  245  49 25   9.0   5.0
 36000 -44.6 -48.3  250  50 26   7.5   4.1 | -43.8 -46.8  240  41 21   9.1   5.0
 34000 -39.5 -39.1  245  41 21   8.7   4.7 | -38.6 -37.5  245  37 19   8.6   4.7
 32000 -34.3 -29.7  245  32 17   8.7   4.8 | -33.4 -28.1  250  34 18   8.7   4.8
 30000 -29.5 -21.1  240  31 16   7.9   4.4 | -28.5 -19.3  245  33 17   8.2   4.5
 29000 -26.5 -15.7  235  32 17   8.0   4.4 | -25.5 -13.9  245  32 16   8.2   4.5
 28000 -24.2 -11.6  235  33 17   7.4   4.0 | -23.1  -9.6  240  32 16   7.2   3.9
 27000 -22.1  -7.8  235  32 16   7.1   3.9 | -21.1  -6.0  235  31 16   6.5   3.6
 26000 -20.0  -4.0  235  31 16   7.1   3.9 | -19.2  -2.6  235  30 15   6.6   3.6
 25000 -17.9  -0.2  230  30 15   7.1   3.9 | -17.3   0.9  230  29 15   6.5   3.6
 24000 -16.0   3.2  230  29 15   6.6   3.6 | -15.3   4.5  225  29 15   6.8   3.7
 23000 -14.0   6.8  230  28 14   6.6   3.6 | -13.3   8.1  225  30 15   6.8   3.8
 22000 -12.1  10.2  230  27 14   6.7   3.7 | -11.3  11.7  225  30 16   7.0   3.8
 21000 -10.3  13.5  230  27 14   6.2   3.4 |  -9.6  14.7  220  31 16   5.9   3.2
 20000  -8.5  16.7  230  28 15   6.2   3.4 |  -7.8  18.0  215  32 17   5.9   3.3
 19500  -7.6  18.3  225  29 15   6.2   3.4 |  -7.0  19.4  215  33 17   5.9   3.3
 19000  -6.7  19.9  225  29 15   6.0   3.3 |  -6.1  21.0  210  33 17   5.6   3.1
 18500  -5.8  21.6  225  29 15   5.9   3.2 |  -5.4  22.3  210  33 17   5.4   2.9
 18000  -5.0  23.0  225  30 15   5.9   3.2 |  -4.6  23.7  210  33 17   5.3   2.9
 17500  -4.1  24.6  225  29 15   5.7   3.1 |  -3.8  25.2  210  33 17   5.7   3.1
 17000  -3.3  26.1  220  28 15   5.7   3.1 |  -3.0  26.6  205  33 17   5.7   3.1
 16500  -2.4  27.7  220  28 14   5.9   3.3 |  -2.2  28.0  205  33 17   5.6   3.1
 16000  -1.6  29.1  220  27 14   6.0   3.3 |  -1.4  29.5  205  33 17   5.6   3.1
 15500  -0.7  30.7  215  26 13   6.1   3.4 |  -0.6  30.9  205  32 17   5.6   3.1
 15000   0.2  32.4  215  25 13   6.5   3.6 |   0.2  32.4  205  31 16   5.7   3.1
 14500   1.1  34.0  215  25 13   6.5   3.5 |   1.0  33.8  205  30 15   5.6   3.1
 14000   2.6  36.7  215  23 12   6.7   3.7 |   2.4  36.3  205  26 14   6.7   3.7
 13500   3.5  38.3  210  22 12   6.9   3.8 |   3.3  37.9  205  24 12   6.9   3.8
 13000   4.5  40.1  210  20 11   7.4   4.0 |   4.4  39.9  205  22 11   8.2   4.5
 12500   5.6  42.1  205  18  9   7.4   4.1 |   5.6  42.1  205  20 10   8.1   4.5
 12000   6.6  43.9  205  16  8   7.6   4.2 |   6.7  44.1  205  18  9   8.4   4.6
 11500   7.7  45.9  205  15  8   7.6   4.2 |   8.0  46.4  205  17  9   8.7   4.7
 11000   8.7  47.7  200  13  7   6.3   3.5 |   9.0  48.2  205  15  8   6.2   3.4
 10500   9.6  49.3  195  12  6   9.0   4.9 |  10.0  50.0  210  13  7   7.9   4.4
 10250  10.4  50.7  195  11  6   9.6   5.3 |  10.6  51.1  215  12  6   8.3   4.6
 10000  10.9  51.6  190  11  5   6.5   3.6 |  11.1  52.0  215  12  6   6.4   3.5
  9750  11.4  52.5  190  10  5   7.4   4.1 |  11.6  52.9  220  11  5   6.7   3.7
  9500  11.9  53.4  190   9  5   7.0   3.8 |  12.0  53.6  225  10  5   6.7   3.7
  9250  12.4  54.3  190   9  4   6.9   3.8 |  12.5  54.5  230   9  5   6.6   3.6
  9000  12.9  55.2  190   7  4   7.3   4.0 |  13.0  55.4  235   8  4   6.2   3.4
  8750  13.5  56.3  195   6  3   7.6   4.1 |  13.4  56.1  245   7  4   6.1   3.3
  8500  14.0  57.2  200   4  2   7.6   4.2 |  13.8  56.8  255   7  3   6.1   3.3
  8250  14.6  58.3  205   3  2   7.8   4.3 |  14.3  57.7  265   6  3   6.7   3.7
  8000  15.1  59.2  215   2  1   7.6   4.2 |  14.8  58.6  280   6  3   6.0   3.3
  7750  15.6  60.1  230   2  1   7.0   3.8 |  15.2  59.4  290   6  3   5.0   2.8
  7500  16.1  61.0  250   2  1   8.2   4.5 |  15.6  60.1  300   6  3   5.6   3.1
  7250  16.8  62.2  265   2  1  10.0   5.5 |  16.0  60.8  310   7  4   6.0   3.3
  7000  17.5  63.5  270   2  1  10.0   5.5 |  16.4  61.5  310   7  4   6.7   3.7
  6750  18.3  64.9  275   2  1   9.8   5.4 |  16.9  62.4  310   8  4   6.6   3.6
  6500  19.0  66.2  275   2  1  10.6   5.8 |  17.4  63.3  315   8  4   8.2   4.5
  6250  19.8  67.6  275   2  1  11.4   6.3 |  18.1  64.6  315   8  4   9.8   5.4
  6000  20.7  69.3  275   2  1  10.8   5.9 |  18.8  65.8  310   8  4   9.7   5.3
  5750  21.5  70.7  275   2  1  11.8   6.5 |  19.5  67.1  310   8  4   9.5   5.2
  5500  22.4  72.3  275   2  1  14.2   7.8 |  20.2  68.4  310   8  4   8.3   4.5
  5250  23.5  74.3  280   3  1  15.0   8.3 |  20.7  69.3  310   7  4   7.1   3.9
  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




U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE