Soaring Guidance
Issued by NWS Pueblo, CO

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166
UXUS97 KPUB 251357
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0757 MDT Friday, May 25, 2018

This forecast is for Friday, May 25, 2018:

If the trigger temperature of 68.5 F/20.3 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1806 ft/min (9.2 m/s)
   Maximum height of thermals.................. 25627 ft MSL (18043 ft AGL)

Forecast maximum temperature................... 83.0 F/28.8 C
Time of trigger temperature.................... 0930 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 21681 ft MSL (14096 ft AGL)
Thermal soaring outlook for Saturday 05/26..... Excellent

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

Remarks...

Sunrise/Sunset.................... 05:38:53 / 20:13:37 MDT
Total possible sunshine........... 14 hr 34 min 44 sec (874 min 44 sec)
Altitude of sun at 12:56:15 MDT... 72.03 degrees

Upper air data from numerical model forecast valid on 05/25/2018 at 0600 MDT

Freezing level.................. 14897 ft MSL (7313 ft AGL)
Convective condensation level... 16818 ft MSL (9234 ft AGL)
Lifted condensation level....... 19434 ft MSL (11850 ft AGL)
Lifted index.................... -6.2
K index......................... +17.0

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -61.2 -78.2   260    9    5   2.4   1.3      M     M       M      M    M
 45000  -57.9 -72.2   260   12    6   1.0   0.5      M     M       M      M    M
 40000  -56.3 -69.3   260   14    7   4.5   2.5      M     M       M      M    M
 38000  -52.6 -62.7   255   12    6   6.2   3.4      M     M       M      M    M
 36000  -48.9 -56.0   255   10    5   6.2   3.4      M     M       M      M    M
 34000  -44.8 -48.6   255    9    5   7.4   4.1      M     M       M      M    M
 32000  -39.8 -39.6   260    9    5   7.4   4.1      M     M       M      M    M
 30000  -35.5 -31.9   265    9    5   7.0   3.8   32.6  90.7     3.3      M    M
 29000  -33.4 -28.1   270   10    5   7.0   3.8   31.6  88.9     2.6      M    M
 28000  -31.4 -24.5   270   10    5   7.0   3.8   30.7  87.2     1.9      M    M
 27000  -29.2 -20.6   275   10    5   7.2   4.0   29.6  85.4     1.1      M    M
 26000  -27.1 -16.8   275   10    5   7.2   4.0   28.7  83.6     0.3      M    M
 25000  -24.9 -12.8   280   10    5   7.2   4.0   27.8  82.1    -0.4   1748  8.9
 24000  -22.7  -8.9   280   11    6   7.3   4.0   26.9  80.4    -1.2   1653  8.4
 23000  -20.6  -5.1   280   12    6   7.3   4.0   26.0  78.8    -2.0   1559  7.9
 22000  -18.4  -1.1   285   13    6   7.2   3.9   25.2  77.3    -2.7   1465  7.4
 21000  -16.1   3.0   285   13    7   8.1   4.4   24.5  76.1    -3.4   1365  6.9
 20000  -13.7   7.3   285   13    7   8.1   4.4   23.9  75.0    -4.0   1264  6.4
 19500  -12.5   9.5   285   13    7   8.1   4.4   23.6  74.6    -4.2   1213  6.2
 19000  -10.8  12.6   285   13    7   7.1   3.9   23.2  73.7    -4.7   1140  5.8
 18500   -9.8  14.4   285   13    7   7.3   4.0   22.7  72.9    -5.2   1094  5.6
 18000   -8.7  16.3   285   13    6   8.5   4.7   22.4  72.2    -5.6   1048  5.3
 17500   -7.3  18.9   290   12    6   9.3   5.1   22.3  72.1    -5.7    992  5.0
 17000   -5.9  21.4   290   12    6   9.4   5.1   22.2  72.0    -5.8    936  4.8
 16500   -4.5  23.9   295   11    6   9.8   5.4   22.2  71.9    -5.9    878  4.5
 16000   -3.1  26.4   295   11    6   9.8   5.4   22.2  71.9    -5.9    820  4.2
 15500   -1.6  29.1   295   10    5   9.8   5.4   22.2  72.0    -6.0    762  3.9
 15000   -0.2  31.6   295   10    5   9.8   5.4   22.2  72.0    -6.0    703  3.6
 14500    1.3  34.3   295    9    5   9.8   5.4   22.2  72.0    -6.0    645  3.3
 14000    2.7  36.9   295    9    4   9.8   5.4   22.2  72.0    -6.1    587  3.0
 13500    4.2  39.6   295    8    4   9.4   5.1   22.2  72.0    -6.2    530  2.7
 13000    5.4  41.7   285    7    3   8.2   4.5   22.1  71.7    -6.4    479  2.4
 12500    6.5  43.7   275    6    3   7.9   4.4   21.8  71.2    -6.8    430  2.2
 12000    7.5  45.5   265    6    3   6.4   3.5   21.4  70.5    -7.3    385  2.0
 11750    8.0  46.4   260    5    3   6.7   3.7   21.1  70.0    -7.6    364  1.8
 11500    8.5  47.3   255    5    3   7.9   4.3   20.9  69.7    -7.8    341  1.7
 11250    9.1  48.4   250    5    3   7.5   4.1   20.8  69.4    -8.0    317  1.6
 11000    9.5  49.1   245    5    3   6.7   3.7   20.6  69.0    -8.3    295  1.5
 10750   10.0  50.0   235    5    2   6.4   3.5   20.3  68.6    -8.5    273  1.4
 10500   10.5  50.9   230    5    2   8.2   4.5   20.1  68.2    -8.8    251  1.3
 10250   11.2  52.2   225    5    2   8.6   4.7   20.1  68.1    -8.9    224  1.1
 10000   11.7  53.1   220    5    2   6.9   3.8   19.9  67.8    -9.1    201  1.0
  9750   12.2  54.0   215    5    2   7.6   4.2   19.7  67.4    -9.3    177  0.9
  9500   12.8  55.0   210    5    2   6.5   3.5   19.5  67.1    -9.5    154  0.8
  9250   13.2  55.8   205    5    2   5.6   3.1   19.2  66.6    -9.9    134  0.7
  9000   13.7  56.7   210    5    2   7.2   4.0   18.9  66.1   -10.1    112  0.6
  8750   14.2  57.6   210    5    2   8.6   4.7   18.8  65.8   -10.3     87  0.4
  8500   14.8  58.6   215    5    2   6.6   3.6   18.7  65.6   -10.5     63  0.3
  8250   15.1  59.2   220    4    2  -0.2  -0.1   18.2  64.8   -11.0     48  0.2
  8000   14.5  58.1   225    4    2 -16.4  -9.0   16.9  62.5   -12.3     56  0.3
  7750   12.6  54.7   235    3    2 -33.6 -18.4   14.3  57.7   -15.0    107  0.5
  7500      M     M     M    M    M     M     M      M     M       M      M    M
  7250      M     M     M    M    M     M     M      M     M       M      M    M
  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 * * * * * *

           05/25/2018 at 0900 MDT          |       05/25/2018 at 1200 MDT
                                           |
CAPE...  +314.0    LI...       -1.1        | CAPE...  +230.6    LI...       -1.0
CINH...   -44.2    K Index...  +8.7        | CINH...    -1.2    K Index... +21.1
                                           |
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 -61.9 -79.4  250   8  4   2.2   1.2 | -62.1 -79.8  250   9  4   2.0   1.1
 45000 -58.8 -73.8  260   9  5   1.4   0.7 | -59.1 -74.4  255  10  5   1.6   0.9
 40000 -56.6 -69.9  275  13  7   5.0   2.8 | -56.7 -70.1  275  12  6   5.1   2.8
 38000 -52.9 -63.2  275  13  7   6.1   3.4 | -53.0 -63.4  275  12  6   6.1   3.3
 36000 -49.2 -56.6  270  12  6   6.1   3.4 | -49.3 -56.7  280  13  7   6.1   3.3
 34000 -45.0 -49.0  275  12  6   7.6   4.2 | -45.1 -49.2  280  13  7   7.6   4.2
 32000 -39.9 -39.8  275  12  6   7.6   4.2 | -40.0 -40.0  280  13  7   7.6   4.2
 30000 -35.4 -31.7  280  12  6   7.4   4.1 | -35.5 -31.9  285  13  7   7.5   4.1
 29000 -33.2 -27.8  280  12  6   7.4   4.1 | -33.2 -27.8  285  13  7   7.5   4.1
 28000 -31.0 -23.8  280  13  7   7.4   4.1 | -31.0 -23.8  290  13  7   7.5   4.1
 27000 -28.8 -19.8  280  13  7   7.3   4.0 | -28.7 -19.7  290  14  7   7.5   4.1
 26000 -26.6 -15.9  280  13  7   7.3   4.0 | -26.5 -15.7  290  14  7   7.5   4.1
 25000 -24.4 -11.9  280  13  7   7.3   4.0 | -24.3 -11.7  290  14  7   7.5   4.1
 24000 -22.3  -8.1  280  13  7   7.3   4.0 | -22.0  -7.6  285  14  7   7.4   4.1
 23000 -20.1  -4.2  280  13  7   7.3   4.0 | -19.8  -3.6  285  14  7   7.4   4.1
 22000 -17.9  -0.2  280  13  6   7.2   4.0 | -17.6   0.3  280  14  7   7.5   4.1
 21000 -15.6   3.9  275  12  6   8.0   4.4 | -15.4   4.3  280  13  7   7.4   4.0
 20000 -13.2   8.2  275  12  6   8.0   4.4 | -13.2   8.2  275  13  7   7.4   4.1
 19500 -12.0  10.4  275  11  6   8.0   4.4 | -12.2  10.0  275  13  7   7.5   4.1
 19000 -10.8  12.6  275  11  6   7.6   4.2 | -10.5  13.1  270  12  6   8.1   4.5
 18500  -9.2  15.4  275  11  6   7.4   4.1 |  -9.3  15.3  270  11  6   8.2   4.5
 18000  -8.1  17.4  275  11  6   8.0   4.4 |  -8.2  17.2  270  10  5   8.6   4.7
 17500  -6.9  19.6  280  10  5   8.3   4.5 |  -6.9  19.6  270   8  4   8.8   4.8
 17000  -5.7  21.7  280  10  5   8.4   4.6 |  -5.6  21.9  270   7  3   8.9   4.9
 16500  -4.4  24.1  285   9  5   9.4   5.1 |  -4.2  24.4  270   6  3   9.7   5.3
 16000  -3.0  26.6  290   8  4   9.3   5.1 |  -2.8  27.0  270   5  3   9.7   5.3
 15500  -1.6  29.1  295   8  4   9.6   5.2 |  -1.4  29.5  270   5  2   9.4   5.2
 15000  -0.2  31.6  295   7  4   9.6   5.2 |  -0.0  32.0  270   4  2   9.4   5.2
 14500   1.2  34.2  300   6  3   9.5   5.2 |   1.4  34.5  270   3  2   9.5   5.2
 14000   2.6  36.7  300   6  3   9.4   5.2 |   2.8  37.0  270   3  1   9.6   5.3
 13500   3.9  39.0  295   5  3   9.1   5.0 |   4.2  39.6  265   2  1   9.6   5.3
 13000   5.2  41.4  290   4  2   8.7   4.8 |   5.6  42.1  260   2  1   9.8   5.4
 12500   6.6  43.9  285   3  2   9.9   5.4 |   7.1  44.8  255   2  1   9.9   5.4
 12000   7.8  46.0  280   3  1   7.5   4.1 |   8.5  47.3  240   1  1   8.6   4.7
 11750   8.4  47.1  275   3  1   8.5   4.6 |   9.1  48.4  235   1  1   9.5   5.2
 11500   9.1  48.4  270   3  1  10.8   5.9 |   9.9  49.8  230   1  1  11.1   6.1
 11250   9.8  49.6  265   3  1   8.4   4.6 |  10.7  51.3  225   1  1   9.7   5.3
 11000  10.3  50.5  260   3  1   6.2   3.4 |  11.3  52.3  220   1  1   8.7   4.7
 10750  10.7  51.3  255   3  2   5.6   3.1 |  12.0  53.6  210   1  1   7.9   4.3
 10500  11.2  52.2  250   3  2  10.3   5.6 |  12.6  54.7  205   1  1  12.0   6.6
 10250  12.1  53.8  240   4  2  10.2   5.6 |  13.7  56.7  200   1  1  12.8   7.0
 10000  12.5  54.5  240   4  2   5.3   2.9 |  14.4  57.9  195   1  1   9.1   5.0
  9750  13.0  55.4  235   4  2   6.7   3.7 |  15.2  59.4  190   1  1  10.7   5.9
  9500  13.4  56.1  235   4  2   5.9   3.2 |  15.9  60.6  185   1  1   8.0   4.4
  9250  13.9  57.0  235   4  2   6.6   3.6 |  16.4  61.5  185   1  1   7.8   4.3
  9000  14.4  57.9  230   4  2   8.0   4.4 |  17.2  63.0  180   2  1  11.1   6.1
  8750  15.0  59.0  230   3  2   8.0   4.4 |  18.0  64.4  175   2  1  11.4   6.2
  8500  15.5  59.9  225   3  2   8.4   4.6 |  18.8  65.8  175   2  1  10.8   5.9
  8250  16.1  61.0  225   3  1   9.9   5.4 |  19.6  67.3  170   2  1  10.7   5.8
  8000  17.0  62.6  220   3  1  13.9   7.6 |  20.6  69.1  170   2  1  17.7   9.7
  7750  18.2  64.8  220   2  1  18.3  10.1 |  22.3  72.1  165   2  1  27.8  15.2
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  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

           05/25/2018 at 1500 MDT          |       05/25/2018 at 1800 MDT
                                           |
CAPE...  +326.2    LI...       -0.8        | CAPE...   +20.4    LI...       +0.1
CINH...   -12.3    K Index... +26.0        | CINH...   -57.1    K Index... +16.3
                                           |
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 -62.4 -80.3  195  40 21   2.0   1.1 | -62.9 -81.2  195  48 25   1.4   0.8
 45000 -59.4 -74.9  205  28 15   1.6   0.9 | -60.6 -77.1  275  15  8   1.6   0.9
 40000 -56.9 -70.4  350 110 57   5.2   2.9 | -58.0 -72.4  350  89 46   6.2   3.4
 38000 -53.3 -63.9  355 139 71   6.0   3.3 | -53.8 -64.8  355 125 64   6.9   3.8
 36000 -49.7 -57.5  355 168 86   6.1   3.3 | -49.7 -57.5  355 161 83   6.9   3.8
 34000 -45.2 -49.4  355 170 88   8.1   4.4 | -44.4 -47.9  355 170 88   8.2   4.5
 32000 -39.8 -39.6  355 159 82   8.1   4.4 | -39.5 -39.1  355 168 86   8.1   4.5
 30000 -35.4 -31.7  355 128 66   7.0   3.8 | -34.7 -30.5  355 171 88   8.1   4.5
 29000 -33.3 -27.9  350 109 56   7.0   3.8 | -32.2 -26.0  355 174 89   8.1   4.5
 28000 -31.2 -24.2  350  90 46   7.2   3.9 | -29.8 -21.6  355 176 91   7.7   4.2
 27000 -28.9 -20.0  350  89 46   7.8   4.3 | -27.8 -18.0  355 153 79   6.5   3.6
 26000 -26.6 -15.9  350  90 46   7.8   4.3 | -25.9 -14.6  355 127 65   6.5   3.6
 25000 -24.3 -11.7  350  92 47   7.8   4.3 | -23.9 -11.0  350 100 52   6.4   3.5
 24000 -22.0  -7.6  350  81 42   7.7   4.2 | -21.7  -7.1  345  66 34   7.9   4.3
 23000 -19.7  -3.5  350  64 33   7.8   4.3 | -19.4  -2.9  330  28 14   8.0   4.4
 22000 -17.5   0.5  345  47 24   7.9   4.3 | -17.1   1.2  220  19 10   8.2   4.5
 21000 -15.0   5.0  340  30 15   8.6   4.7 | -14.7   5.5  200  29 15   8.5   4.7
 20000 -11.9  10.6  305  11  6   8.7   4.8 | -11.5  11.3  195  34 17   8.5   4.7
 19500 -10.7  12.7  255   8  4   8.7   4.8 | -10.3  13.5  195  36 18   8.6   4.7
 19000  -9.4  15.1  285   7  4   8.4   4.6 |  -8.9  16.0  190  38 20   9.6   5.3
 18500  -8.2  17.2  335  12  6   8.5   4.6 |  -7.5  18.5  190  41 21   9.5   5.2
 18000  -7.0  19.4  345  20 10   8.4   4.6 |  -6.1  21.0  190  46 23   9.6   5.3
 17500  -5.7  21.7  350  20 10   8.4   4.6 |  -4.6  23.7  185  57 29   9.6   5.3
 17000  -4.5  23.9  350  20 10   8.5   4.7 |  -3.2  26.2  185  68 35   9.6   5.2
 16500  -3.2  26.2  190  11  6   9.2   5.0 |  -1.8  28.8  185  83 43   9.3   5.1
 16000  -1.8  28.8  180  53 27   9.1   5.0 |  -0.4  31.3  180 100 51   9.4   5.2
 15500  -0.4  31.3  180  97 50   9.4   5.1 |   1.0  33.8  180 117 60   9.1   5.0
 15000   1.0  33.8  180 144 74   9.4   5.1 |   2.3  36.1  180 136 70   9.0   5.0
 14500   2.4  36.3  180 186 96   9.2   5.1 |   3.7  38.7  180 154 79   9.0   4.9
 14000   3.7  38.7  180 174 90   9.2   5.0 |   5.0  41.0  180 169 87   9.0   4.9
 13500   5.1  41.2  180 162 83   9.2   5.0 |   6.4  43.5  180 183 94   8.9   4.9
 13000   6.5  43.7  180 155 80   9.0   4.9 |   7.7  45.9  180 188 97   8.4   4.6
 12500   7.7  45.9  180 147 75   8.1   4.5 |   8.9  48.0  180 187 96   7.5   4.1
 12000   8.9  48.0  180 145 75   7.7   4.2 |  10.0  50.0  180 186 96   7.9   4.3
 11750   9.5  49.1  180 146 75   8.6   4.7 |  10.6  51.1  180 184 95   8.1   4.4
 11500  10.2  50.4  180 144 74  10.6   5.8 |  11.2  52.2  180 182 94   8.6   4.7
 11250  11.0  51.8  180 141 73   9.7   5.3 |  11.8  53.2  180 179 92   8.2   4.5
 11000  11.6  52.9  180 142 73   8.7   4.8 |  12.4  54.3  180 178 91   8.0   4.4
 10750  12.3  54.1  180 143 73   8.2   4.5 |  13.0  55.4  180 176 91   7.4   4.1
 10500  12.9  55.2  180 143 74  11.1   6.1 |  13.6  56.5  180 174 90   9.8   5.4
 10250  13.9  57.0  180 142 73  11.8   6.5 |  14.4  57.9  180 170 87  10.9   6.0
 10000  14.6  58.3  180 142 73   9.2   5.0 |  15.1  59.2  180 168 87   9.2   5.1
  9750  15.3  59.5  180 142 73  10.2   5.6 |  15.8  60.4  180 167 86   9.8   5.4
  9500  16.0  60.8  180 143 73   8.8   4.8 |  16.6  61.9  180 165 85   9.3   5.1
  9250  16.7  62.1  180 144 74   8.7   4.8 |  17.2  63.0  180 165 85   8.9   4.9
  9000  17.4  63.3  180 144 74  10.4   5.7 |  17.9  64.2  180 165 85   9.5   5.2
  8750  18.2  64.8  180 144 74  10.6   5.8 |  18.6  65.5  180 163 84   9.9   5.4
  8500  19.0  66.2  180 144 74  10.4   5.7 |  19.4  66.9  180 162 83   9.8   5.4
  8250  19.8  67.6  180 144 74  11.5   6.3 |  20.1  68.2  180 161 83  11.3   6.2
  8000  20.8  69.4  180 145 74  17.9   9.8 |  21.0  69.8  180 161 83  12.1   6.6
  7750  22.4  72.3  180 143 73  25.6  14.0 |  21.8  71.2  180 159 82  10.3   5.6
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  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).  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



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