Soaring Guidance
Issued by NWS Pueblo, 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 13 14
965
UXUS97 KPUB 311410
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0710 MST Sunday, January 31, 2016

This forecast is for Sunday, January 31, 2016:

If the trigger temperature of 40.9 F/4.9 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 8176 ft MSL (1006 ft AGL)

Forecast maximum temperature................... 30.0 F/-1.6 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. None
Thermal soaring outlook for Monday 02/01....... Poor

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

Remarks...

Sunrise/Sunset.................... 07:06:21 / 17:17:30 MST
Total possible sunshine........... 10 hr 11 min 8 sec (611 min 8 sec)
Altitude of sun at 12:12:17 MST... 33.72 degrees

Upper air data from numerical model forecast valid on 01/31/2016 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 12067 ft MSL (4897 ft AGL)
Lifted condensation level....... 9281 ft MSL (2112 ft AGL)
Lifted index.................... +9.3
K index......................... +18.5

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  -54.8 -66.6   275   59   30   4.8   2.6      M     M       M      M    M
 45000  -47.7 -53.9   280   69   36   3.6   2.0      M     M       M      M    M
 40000  -43.0 -45.4   280   68   35   3.1   1.7      M     M       M      M    M
 38000  -42.0 -43.6   280   73   38  -1.1  -0.6      M     M       M      M    M
 36000  -42.7 -44.9   285   85   44  -1.1  -0.6      M     M       M      M    M
 34000  -43.3 -45.9   290   97   50  -1.3  -0.7      M     M       M      M    M
 32000  -44.7 -48.5   285   97   50  -2.5  -1.4      M     M       M      M    M
 30000  -46.2 -51.2   280   96   50  -2.4  -1.3      M     M       M      M    M
 29000  -44.9 -48.8   280   95   49   6.1   3.4   22.5  72.5    18.2      M    M
 28000  -43.1 -45.6   280   94   48   6.1   3.3   21.0  69.8    17.3      M    M
 27000  -41.3 -42.3   280   93   48   6.1   3.3   19.7  67.4    16.5      M    M
 26000  -39.2 -38.6   280   92   47   9.4   5.2   18.8  65.8    15.9      M    M
 25000  -36.4 -33.5   280   91   47   9.2   5.1   18.5  65.3    15.9      M    M
 24000  -33.0 -27.4   280   89   46   9.2   5.0   18.3  65.0    16.0      M    M
 23000  -30.6 -23.1   280   88   45   6.7   3.7   17.6  63.7    15.6      M    M
 22000  -28.7 -19.7   280   86   44   6.6   3.6   16.4  61.6    14.8      M    M
 21000  -26.7 -16.1   275   84   43   6.5   3.6   15.4  59.7    14.0      M    M
 20000  -24.7 -12.5   275   80   41   7.1   3.9   14.4  57.9    13.3      M    M
 19500  -23.6 -10.5   275   78   40   7.1   3.9   13.9  57.1    12.9      M    M
 19000  -22.6  -8.7   275   76   39   7.1   3.9   13.5  56.3    12.6      M    M
 18500  -21.5  -6.7   270   74   38   7.3   4.0   13.1  55.5    12.3      M    M
 18000  -20.6  -5.1   270   72   37   4.3   2.4   12.5  54.5    11.9      M    M
 17500  -20.0  -4.0   270   68   35   3.8   2.1   11.5  52.7    11.0      M    M
 17000  -19.5  -3.1   270   64   33   4.5   2.5   10.5  50.9    10.2      M    M
 16500  -18.6  -1.5   270   60   31   6.3   3.5    9.8  49.7     9.6      M    M
 16000  -17.7   0.1   270   56   29   6.1   3.3    9.3  48.7     9.1      M    M
 15500  -16.6   2.1   265   51   26   8.5   4.6    8.8  47.9     8.8      M    M
 15000  -15.4   4.3   265   46   24   8.4   4.6    8.6  47.5     8.6      M    M
 14500  -14.3   6.3   260   40   21   6.2   3.4    8.2  46.8     8.3      M    M
 14000  -13.5   7.7   260   34   18   6.0   3.3    7.6  45.7     7.7      M    M
 13500  -12.6   9.3   255   28   15   6.9   3.8    7.0  44.7     7.2      M    M
 13000  -11.5  11.3   260   25   13   7.4   4.1    6.7  44.0     6.9      M    M
 12500  -10.4  13.3   260   22   12   9.3   5.1    6.3  43.4     6.6      M    M
 12000   -8.8  16.2   260   21   11   8.9   4.9    6.5  43.6     6.7      M    M
 11750   -8.2  17.2   260   20   10   8.0   4.4    6.3  43.3     6.6      M    M
 11500   -7.7  18.1   260   19   10   6.3   3.5    6.1  43.1     6.4      M    M
 11250   -7.3  18.9   255   19   10   4.3   2.4    5.8  42.4     6.1      M    M
 11000   -7.0  19.4   255   19   10   4.9   2.7    5.4  41.7     5.7      M    M
 10750   -6.6  20.1   255   19   10   5.4   3.0    5.0  41.0     5.4      M    M
 10500   -6.2  20.8   255   19   10   5.1   2.8    4.7  40.4     5.0      M    M
 10250   -5.9  21.4   255   18    9   4.6   2.5    4.3  39.7     4.7      M    M
 10000   -5.5  22.1   250   18    9   4.3   2.3    3.9  39.0     4.3      M    M
  9750   -5.2  22.6   250   17    9   6.1   3.3    3.5  38.3     3.9      M    M
  9500   -4.4  24.1   245   16    8   2.9   1.6    2.8  37.0     3.2      M    M
  9250   -4.2  24.4   240   15    8   3.8   2.1    2.3  36.1     2.8      M    M
  9000   -3.9  25.0   235   14    7   2.8   1.5    1.8  35.2     2.3      M    M
  8750   -3.8  25.2   230   12    6  -0.7  -0.4    1.2  34.1     1.7      M    M
  8500   -4.0  24.8   225   11    6  -2.3  -1.3    0.3  32.5     0.8      M    M
  8250   -4.1  24.6   215   10    5  -2.2  -1.2   -0.6  30.9    -0.1    156  0.8
  8000   -4.2  24.4   205    9    5  -0.4  -0.2   -1.5  29.3    -0.9    153  0.8
  7750   -4.1  24.6   200    6    3   3.6   2.0   -2.1  28.2    -1.5    141  0.7
  7500   -3.8  25.2   180    5    2   4.6   2.5   -2.5  27.5    -1.9    124  0.6
  7250   -3.5  25.7   150    4    2   4.6   2.5   -2.9  26.8    -2.3    107  0.5
  7000      M     M     M    M    M     M     M      M     M       M      M    M
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           01/31/2016 at 0800 MST          |       01/31/2016 at 1100 MST
                                           |
K index... +11.5  LI... +276.9             | K index... +9.7  LI... +276.4
CAPE... 0.0  CIN... -2.6                   | CAPE... 0.0  CIN... -0.5
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -55.5 -67.9  270  68 35   4.4   2.4 | -55.0 -67.0  270  65 33   4.3   2.4
 45000 -48.5 -55.3  275  82 42   4.0   2.2 | -48.5 -55.3  275  79 40   3.8   2.1
 40000 -42.6 -44.7  275  74 38   3.9   2.2 | -43.1 -45.6  275  82 42   3.6   2.0
 38000 -41.6 -42.9  275  74 38  -2.2  -1.2 | -42.0 -43.6  275  84 43  -1.4  -0.8
 36000 -42.9 -45.2  280  82 42  -2.1  -1.2 | -42.9 -45.2  275  86 44  -1.4  -0.8
 34000 -44.2 -47.6  285  90 46  -2.1  -1.2 | -43.7 -46.7  275  89 46  -1.6  -0.9
 32000 -45.6 -50.1  280  90 46  -2.3  -1.2 | -45.0 -49.0  270  84 43  -2.2  -1.2
 30000 -46.9 -52.4  275  88 45  -3.3  -1.8 | -46.3 -51.3  265  79 40  -1.0  -0.6
 29000 -45.5 -49.9  275  84 43   7.8   4.3 | -44.7 -48.5  265  75 38   6.5   3.6
 28000 -42.5 -44.5  275  76 39   7.8   4.3 | -42.8 -45.0  265  70 36   6.5   3.6
 27000 -40.2 -40.4  275  70 36   7.8   4.3 | -40.9 -41.6  265  66 34   6.5   3.6
 26000 -37.9 -36.2  275  68 35   7.4   4.0 | -38.7 -37.7  270  63 32   8.4   4.6
 25000 -35.7 -32.3  280  71 36   7.4   4.0 | -36.2 -33.2  270  61 32   8.3   4.6
 24000 -33.5 -28.3  280  74 38   7.4   4.0 | -33.7 -28.7  275  60 31   8.3   4.6
 23000 -31.4 -24.5  285  75 39   7.0   3.8 | -30.8 -23.4  280  60 31   7.6   4.1
 22000 -29.3 -20.7  285  75 38   7.0   3.8 | -28.5 -19.3  280  60 31   7.5   4.1
 21000 -27.2 -17.0  285  74 38   7.0   3.8 | -26.3 -15.3  280  60 31   7.6   4.2
 20000 -25.1 -13.2  280  71 37   7.0   3.9 | -24.2 -11.6  280  59 30   7.1   3.9
 19500 -24.1 -11.4  280  69 36   7.0   3.9 | -23.1  -9.6  275  59 30   7.1   3.9
 19000 -23.0  -9.4  275  68 35   7.0   3.9 | -22.1  -7.8  275  58 30   7.1   3.9
 18500 -22.0  -7.6  275  66 34   7.0   3.9 | -21.0  -5.8  275  57 29   7.1   3.9
 18000 -20.9  -5.6  270  65 33   7.3   4.0 | -20.0  -4.0  270  57 29   6.4   3.5
 17500 -19.8  -3.6  270  63 33   7.5   4.1 | -19.1  -2.4  270  56 29   6.3   3.5
 17000 -18.7  -1.7  270  62 32   7.3   4.0 | -18.1  -0.6  270  56 29   6.7   3.7
 16500 -17.7   0.1  270  61 31   6.4   3.5 | -17.1   1.2  265  55 28   7.2   4.0
 16000 -16.8   1.8  270  60 31   6.8   3.7 | -16.0   3.2  265  54 28   7.3   4.0
 15500 -16.0   3.2  270  57 30   2.6   1.4 | -15.0   5.0  265  53 27   6.8   3.7
 15000 -15.6   3.9  270  52 27   2.6   1.5 | -14.0   6.8  265  51 26   7.0   3.8
 14500 -15.2   4.6  275  46 24   3.3   1.8 | -13.1   8.4  265  48 25   4.5   2.5
 14000 -14.7   5.5  270  42 21   3.7   2.0 | -12.5   9.5  260  45 23   4.3   2.4
 13500 -14.1   6.6  270  37 19   6.4   3.5 | -11.9  10.6  260  41 21   3.3   1.8
 13000 -12.8   9.0  270  34 17   8.4   4.6 | -11.5  11.3  260  36 18   2.9   1.6
 12500 -11.6  11.1  270  30 16   7.7   4.2 | -11.0  12.2  260  30 16   3.2   1.8
 12000 -10.6  12.9  275  27 14   6.3   3.5 | -10.5  13.1  265  25 13   3.3   1.8
 11750 -10.2  13.6  275  24 12   5.4   3.0 | -10.3  13.5  265  23 12   3.1   1.7
 11500  -9.8  14.4  275  21 11   6.2   3.4 | -10.1  13.8  265  20 10   3.0   1.7
 11250  -9.3  15.3  275  19 10   7.0   3.8 |  -9.9  14.2  265  18  9   3.0   1.6
 11000  -8.8  16.2  275  18  9   6.8   3.7 |  -9.7  14.5  265  15  8   3.0   1.6
 10750  -8.3  17.1  280  16  8   7.1   3.9 |  -9.4  15.1  260  12  6   5.4   2.9
 10500  -7.8  18.0  285  15  7   6.1   3.3 |  -9.0  15.8  255   8  4   5.4   2.9
 10250  -7.0  19.4  285  12  6   5.0   2.8 |  -8.7  16.3  250   7  4   3.5   1.9
 10000  -6.6  20.1  285  11  6   6.6   3.6 |  -8.4  16.9  240   6  3   4.4   2.4
  9750  -6.1  21.0  290  10  5   5.2   2.9 |  -8.0  17.6  220   5  3   2.5   1.4
  9500  -5.9  21.4  290   9  4   2.3   1.3 |  -7.7  18.1  200   5  3   4.0   2.2
  9250  -5.7  21.7  285   7  4   3.6   2.0 |  -7.4  18.7  185   6  3   3.4   1.9
  9000  -5.5  22.1  285   6  3   1.2   0.7 |  -7.2  19.0  170   7  3   4.5   2.5
  8750  -5.5  22.1  285   5  2   0.2   0.1 |  -6.7  19.9  160   7  3   8.0   4.4
  8500  -5.4  22.3  280   3  2   1.8   1.0 |  -6.1  21.0  150   7  4   9.6   5.3
  8250  -5.3  22.5  260   2  1   1.1   0.6 |  -5.4  22.3  145   8  4   9.3   5.1
  8000  -5.2  22.6  200   1  0   3.1   1.7 |  -4.7  23.5  135   9  4   9.0   4.9
  7750  -4.8  23.4  075   1  0   8.3   4.5 |  -4.0  24.8  135   8  4  12.6   6.9
  7500  -4.0  24.8  085   2  1  11.9   6.5 |  -2.8  27.0  130   8  4  20.2  11.1
  7250  -3.2  26.2  085   3  1   6.9   3.8 |  -1.6  29.1  125   7  4   6.4   3.5
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           01/31/2016 at 1400 MST          |       01/31/2016 at 1700 MST
                                           |
K index... +14.5  LI... +274.8             | K index... +13.6  LI... +274.6
CAPE... 0.0  CIN... -1.2                   | 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 -56.2 -69.2  265  65 33   4.4   2.4 | -56.1 -69.0  260  54 28   4.3   2.4
 45000 -49.6 -57.3  265  76 39   4.8   2.6 | -49.2 -56.6  260  71 37   4.9   2.7
 40000 -42.4 -44.3  270  87 45   4.8   2.6 | -41.8 -43.2  265  86 44   4.9   2.7
 38000 -40.9 -41.6  270  90 46  -1.5  -0.8 | -40.4 -40.7  265  89 46  -1.7  -0.9
 36000 -41.9 -43.4  270  89 46  -1.5  -0.8 | -41.4 -42.5  265  87 45  -1.6  -0.9
 34000 -42.7 -44.9  270  88 45  -1.6  -0.9 | -42.4 -44.3  260  85 44  -1.6  -0.9
 32000 -43.8 -46.8  265  78 40  -1.8  -1.0 | -43.6 -46.5  260  77 40  -2.1  -1.2
 30000 -44.9 -48.8  265  68 35  -1.2  -0.7 | -44.9 -48.8  260  68 35  -2.6  -1.4
 29000 -44.0 -47.2  260  63 32   4.2   2.3 | -44.5 -48.1  260  62 32   3.2   1.8
 28000 -42.7 -44.9  260  57 29   4.2   2.3 | -43.3 -45.9  260  55 28   3.3   1.8
 27000 -41.5 -42.7  255  52 27   4.2   2.3 | -42.3 -44.1  255  49 25   3.5   1.9
 26000 -39.6 -39.3  255  48 25   9.7   5.3 | -40.4 -40.7  255  46 24   9.4   5.2
 25000 -36.8 -34.2  255  49 25   9.5   5.2 | -37.5 -35.5  255  45 23   9.6   5.3
 24000 -34.0 -29.2  260  49 25   9.5   5.2 | -34.6 -30.3  255  44 23   9.6   5.3
 23000 -30.9 -23.6  260  50 26   7.0   3.8 | -31.9 -25.4  255  43 22   7.9   4.3
 22000 -28.8 -19.8  260  51 26   6.9   3.8 | -29.6 -21.3  255  43 22   7.9   4.3
 21000 -26.8 -16.2  255  52 27   6.9   3.8 | -27.2 -17.0  260  42 22   7.9   4.4
 20000 -24.6 -12.3  255  51 26   7.6   4.2 | -24.9 -12.8  260  45 23   7.9   4.3
 19500 -23.5 -10.3  255  51 26   7.6   4.2 | -23.7 -10.7  265  47 24   7.9   4.3
 19000 -22.3  -8.1  255  50 26   7.6   4.2 | -22.5  -8.5  265  50 26   7.9   4.3
 18500 -21.2  -6.2  255  50 26   7.6   4.1 | -21.3  -6.3  265  53 27   7.9   4.4
 18000 -20.1  -4.2  255  50 26   8.2   4.5 | -20.2  -4.4  270  55 28   7.5   4.1
 17500 -18.9  -2.0  255  49 25   8.2   4.5 | -19.1  -2.4  270  56 29   7.4   4.0
 17000 -17.6   0.3  255  49 25   8.0   4.4 | -18.0  -0.4  265  57 29   7.4   4.1
 16500 -16.5   2.3  255  48 24   7.5   4.1 | -16.8   1.8  265  55 28   7.9   4.4
 16000 -15.4   4.3  255  46 24   7.5   4.1 | -15.7   3.7  260  52 27   7.9   4.4
 15500 -14.4   6.1  255  44 23   6.5   3.5 | -14.5   5.9  260  49 25   7.9   4.3
 15000 -13.5   7.7  250  41 21   6.7   3.7 | -13.3   8.1  250  46 23   8.0   4.4
 14500 -12.6   9.3  250  37 19   4.3   2.4 | -12.3   9.9  245  43 22   5.7   3.1
 14000 -12.0  10.4  245  33 17   4.0   2.2 | -11.6  11.1  235  41 21   4.6   2.5
 13500 -11.5  11.3  240  29 15   3.7   2.0 | -10.9  12.4  225  40 21   2.5   1.4
 13000 -11.0  12.2  240  25 13   3.4   1.9 | -10.9  12.4  220  37 19   0.2   0.1
 12500 -10.4  13.3  240  21 11   2.1   1.2 | -10.8  12.6  210  34 17  -0.8  -0.4
 12000 -10.3  13.5  235  18  9   0.7   0.4 | -11.2  11.8  205  31 16  -2.1  -1.1
 11750 -10.3  13.5  230  16  8   0.0   0.0 | -11.3  11.7  205  29 15  -1.7  -0.9
 11500 -10.3  13.5  220  14  7   0.5   0.3 | -11.4  11.5  200  27 14  -0.1  -0.1
 11250 -10.2  13.6  215  15  7   0.8   0.4 | -11.3  11.7  195  26 14   2.1   1.1
 11000 -10.2  13.6  205  15  8   0.9   0.5 | -11.1  12.0  190  26 13   2.3   1.3
 10750 -10.1  13.8  195  16  8  -1.4  -0.8 | -11.0  12.2  185  26 13   1.4   0.7
 10500 -10.3  13.5  190  17  9   1.1   0.6 | -10.6  12.9  175  24 12   4.2   2.3
 10250 -10.0  14.0  185  17  9   4.6   2.5 | -10.3  13.5  170  22 12   3.7   2.1
 10000  -9.7  14.5  180  17  9   4.2   2.3 | -10.0  14.0  165  21 11   4.4   2.4
  9750  -9.4  15.1  170  17  9   2.3   1.2 |  -9.7  14.5  160  20 10   4.8   2.6
  9500  -8.9  16.0  160  18  9   5.8   3.2 |  -9.3  15.3  150  19 10   4.5   2.5
  9250  -8.5  16.7  155  17  9   4.6   2.5 |  -9.0  15.8  145  19 10   4.5   2.5
  9000  -8.2  17.2  150  17  9   6.5   3.6 |  -8.7  16.3  140  18  9   4.8   2.6
  8750  -7.6  18.3  150  17  9   9.4   5.2 |  -8.2  17.2  135  18  9   7.6   4.1
  8500  -6.8  19.8  150  17  8  10.0   5.5 |  -7.6  18.3  135  18  9   9.2   5.1
  8250  -6.1  21.0  145  16  8  10.0   5.5 |  -6.9  19.6  135  17  9   8.8   4.8
  8000  -5.4  22.3  145  16  8   9.4   5.1 |  -6.3  20.7  135  17  9   8.9   4.9
  7750  -4.7  23.5  145  15  8  12.1   6.7 |  -5.6  21.9  135  16  8  10.2   5.6
  7500  -3.6  25.5  145  13  7  18.5  10.2 |  -4.8  23.4  135  14  7  12.9   7.1
  7250  -2.4  27.7  140  11  6   6.7   3.7 |  -3.9  25.0  135  11  6   8.1   4.4
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     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 near the Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 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.