Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 170013
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1813 MDT Wednesday, May 16, 2018

This forecast is for Thursday, May 17, 2018:

If the trigger temperature of 78.5 F/25.8 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1420 ft/min (7.2 m/s)
   Maximum height of thermals.................. 19596 ft MSL (14289 ft AGL)

Forecast maximum temperature................... 84.0 F/29.3 C
Time of trigger temperature.................... 1145 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................. 9206 ft MSL (3900 ft AGL)
Thermal soaring outlook for Friday 05/18....... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 45603 ft MSL (40296 ft AGL)
Wave soaring outlook for Friday 05/18.......... Poor

Remarks...

***ATTENTION Soaring Forecast Users***The National Weather Service in Boulder wants to hear from you.
Please send and email to paul.t.schlatter@noaa.gov and let us know how you use the Soaring Forecast.  Thanks!

Sunrise/Sunset.................... 05:43:10 / 20:08:26 MDT
Total possible sunshine........... 14 hr 25 min 16 sec (865 min 16 sec)
Altitude of sun at 12:55:59 MDT... 69.66 degrees

Upper air data from numerical model forecast valid on 05/17/2018 at 0600 MDT

Freezing level.................. 14509 ft MSL (9202 ft AGL)
Convective condensation level... 18182 ft MSL (12875 ft AGL)
Lifted condensation level....... 18499 ft MSL (13193 ft AGL)
Lifted index.................... -2.2
K index......................... +8.3

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -58.9 -74.0   265   30   16   1.9   1.1      M     M       M      M    M
 45000  -56.5 -69.7   260   51   26  -1.8  -1.0      M     M       M      M    M
 40000  -59.5 -75.1   255   47   24  -2.6  -1.4      M     M       M      M    M
 38000  -56.9 -70.4   250   43   22   5.5   3.0      M     M       M      M    M
 36000  -53.6 -64.5   245   39   20   5.5   3.0      M     M       M      M    M
 34000  -49.5 -57.1   240   37   19   8.3   4.6      M     M       M      M    M
 32000  -44.5 -48.1   240   37   19   8.3   4.6      M     M       M      M    M
 30000  -38.9 -38.0   235   34   17   8.4   4.6   35.6  96.2     5.1      M    M
 29000  -36.4 -33.5   235   32   16   8.4   4.6   35.1  95.2     4.8      M    M
 28000  -33.9 -29.0   230   30   15   8.4   4.6   34.7  94.4     4.5      M    M
 27000  -31.5 -24.7   230   28   14   7.7   4.2   33.9  93.1     4.0      M    M
 26000  -29.2 -20.6   225   26   13   7.7   4.2   33.1  91.6     3.3      M    M
 25000  -26.9 -16.4   225   24   13   7.7   4.2   32.4  90.3     2.8      M    M
 24000  -24.6 -12.3   220   23   12   8.0   4.4   31.7  89.1     2.3      M    M
 23000  -22.2  -8.0   220   22   11   8.0   4.4   31.0  87.8     1.7      M    M
 22000  -19.8  -3.6   215   21   11   8.0   4.4   30.4  86.7     1.2      M    M
 21000  -17.4   0.7   215   21   11   8.1   4.5   29.8  85.6     0.7      M    M
 20000  -15.0   5.0   215   20   10   8.1   4.5   29.2  84.6     0.2      M    M
 19500  -13.8   7.2   215   19   10   8.2   4.5   28.9  84.1    -0.0   1416  7.2
 19000  -12.5   9.5   215   19   10   8.4   4.6   28.7  83.7    -0.2   1365  6.9
 18500  -11.2  11.8   215   18    9   8.9   4.9   28.5  83.4    -0.4   1311  6.7
 18000   -9.9  14.2   215   17    9   8.9   4.9   28.4  83.1    -0.5   1257  6.4
 17500   -8.6  16.5   215   17    9   9.0   4.9   28.3  82.9    -0.7   1203  6.1
 17000   -7.3  18.9   215   16    8   9.0   4.9   28.1  82.6    -0.8   1148  5.8
 16500   -6.0  21.2   220   15    8   9.2   5.0   28.0  82.4    -1.0   1094  5.6
 16000   -4.6  23.7   220   14    7   9.4   5.1   27.9  82.3    -1.1   1038  5.3
 15500   -2.5  27.5   220   13    6   9.6   5.3   27.8  82.1    -1.2    954  4.8
 15000   -1.1  30.0   225   12    6   9.7   5.3   27.8  82.1    -1.2    896  4.6
 14500    0.3  32.5   225   11    5   9.6   5.3   27.8  82.1    -1.3    839  4.3
 14000    1.7  35.1   230   10    5   9.4   5.1   27.8  82.0    -1.4    782  4.0
 13500    3.1  37.6   235    9    5   9.4   5.1   27.7  81.9    -1.4    725  3.7
 13000    4.5  40.1   245    8    4   9.3   5.1   27.6  81.8    -1.5    668  3.4
 12500    5.9  42.6   255    8    4   9.3   5.1   27.6  81.6    -1.6    612  3.1
 12000    7.3  45.1   265    7    4   8.7   4.8   27.4  81.4    -1.7    557  2.8
 11500    8.6  47.5   275    7    4   8.9   4.9   27.3  81.1    -1.9    503  2.6
 11000    9.8  49.6   285    8    4   7.2   3.9   27.0  80.7    -2.1    452  2.3
 10500   10.8  51.4   290    8    4   7.1   3.9   26.6  79.9    -2.5    405  2.1
 10250   11.4  52.5   290    8    4  10.2   5.6   26.5  79.7    -2.6    380  1.9
 10000   12.3  54.1   295    8    4  10.1   5.5   26.6  79.9    -2.5    348  1.8
  9750   12.9  55.2   295    8    4   7.4   4.1   26.5  79.7    -2.7    322  1.6
  9500   13.5  56.3   295    9    4   8.3   4.5   26.3  79.4    -2.8    297  1.5
  9250   14.0  57.2   295    9    4   7.6   4.2   26.2  79.2    -3.0    272  1.4
  9000   14.6  58.3   290    9    4   7.8   4.3   26.0  78.9    -3.2    249  1.3
  8750   15.2  59.4   290    9    5   8.4   4.6   25.9  78.7    -3.3    224  1.1
  8500   15.8  60.4   290    9    5   8.5   4.6   25.8  78.5    -3.5    199  1.0
  8250   16.4  61.5   290    9    5   7.4   4.0   25.7  78.3    -3.6    173  0.9
  8000   16.8  62.2   285    9    5   6.6   3.6   25.5  77.8    -3.9    152  0.8
  7750   17.3  63.1   280    9    5   7.3   4.0   25.2  77.4    -4.1    130  0.7
  7500   17.8  64.0   280    9    5   7.0   3.8   25.1  77.1    -4.4    108  0.5
  7250   18.3  64.9   275    9    5   5.7   3.1   24.8  76.6    -4.7     87  0.4
  7000   18.6  65.5   270    9    4   4.3   2.3   24.4  76.0    -5.0     68  0.3
  6750   19.0  66.2   265    9    4   5.5   3.0   24.0  75.3    -5.4     51  0.3
  6500   19.2  66.6   260    9    4  -1.7  -0.9   23.6  74.4    -5.9     35  0.2
  6250   18.6  65.5   255    9    4 -12.6  -6.9   22.2  72.0    -7.3     48  0.2
  6000   17.5  63.5   255    9    4 -13.3  -7.3   20.5  68.8    -9.1     72  0.4
  5750   16.4  61.5   250    9    5 -16.2  -8.9   18.7  65.6   -11.0     98  0.5
  5500   14.6  58.3   240    9    5 -31.5 -17.3   16.3  61.3   -13.6    146  0.7

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

           05/17/2018 at 0900 MDT          |       05/17/2018 at 1200 MDT
                                           |
K index... -1.1  LI... +1.2                | K index... -7.7  LI... +0.8
CAPE... 0.0  CIN... 0.0                    | CAPE... +38.0  CIN... -27.6
                                           |
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 -58.2 -72.8  260  28 14   2.4   1.3 | -58.1 -72.6  255  30 15   2.6   1.4
 45000 -55.4 -67.7  260  45 23  -2.4  -1.3 | -55.0 -67.0  260  45 23  -2.5  -1.4
 40000 -59.0 -74.2  255  53 27  -2.9  -1.6 | -59.0 -74.2  255  52 27  -3.0  -1.7
 38000 -56.8 -70.2  250  50 26   5.0   2.8 | -56.8 -70.2  250  50 26   5.0   2.8
 36000 -53.8 -64.8  245  47 24   5.0   2.8 | -53.8 -64.8  245  48 25   5.0   2.8
 34000 -49.9 -57.8  240  44 23   8.3   4.5 | -49.9 -57.8  240  46 23   8.2   4.5
 32000 -44.9 -48.8  240  42 22   8.3   4.5 | -45.0 -49.0  235  44 22   8.2   4.5
 30000 -39.3 -38.7  235  39 20   8.3   4.5 | -39.4 -38.9  235  41 21   8.4   4.6
 29000 -36.8 -34.2  235  36 19   8.3   4.5 | -36.9 -34.4  235  40 21   8.4   4.6
 28000 -34.4 -29.9  235  34 18   8.3   4.6 | -34.4 -29.9  235  39 20   8.4   4.6
 27000 -32.0 -25.6  230  32 16   7.8   4.3 | -31.9 -25.4  230  37 19   8.1   4.5
 26000 -29.6 -21.3  230  29 15   7.8   4.3 | -29.5 -21.1  230  36 18   8.1   4.4
 25000 -27.3 -17.1  225  27 14   7.8   4.3 | -27.0 -16.6  230  34 18   8.1   4.4
 24000 -24.9 -12.8  225  25 13   8.1   4.5 | -24.6 -12.3  230  33 17   7.9   4.3
 23000 -22.5  -8.5  230  25 13   8.1   4.5 | -22.3  -8.1  230  32 16   7.9   4.3
 22000 -20.1  -4.2  230  25 13   8.1   4.5 | -19.9  -3.8  225  31 16   7.9   4.3
 21000 -17.6   0.3  235  26 13   8.3   4.5 | -17.5   0.5  225  30 15   8.4   4.6
 20000 -15.2   4.6  235  28 14   8.3   4.5 | -15.0   5.0  220  30 15   8.4   4.6
 19500 -13.9   7.0  235  28 15   8.3   4.5 | -13.7   7.3  220  29 15   8.4   4.6
 19000 -12.7   9.1  235  29 15   8.4   4.6 | -12.4   9.7  220  29 15   8.5   4.7
 18500 -11.4  11.5  235  29 15   8.9   4.9 | -11.1  12.0  215  29 15   9.1   5.0
 18000 -10.1  13.8  235  29 15   8.9   4.9 |  -9.8  14.4  215  29 15   9.1   5.0
 17500  -8.7  16.3  235  29 15   9.0   5.0 |  -8.4  16.9  215  30 15   8.9   4.9
 17000  -7.4  18.7  235  28 14   9.1   5.0 |  -7.1  19.2  210  30 15   8.9   4.9
 16500  -6.0  21.2  235  26 14   8.9   4.9 |  -5.8  21.6  210  30 15   8.9   4.9
 16000  -4.7  23.5  230  24 13   8.6   4.7 |  -4.4  24.1  210  30 15   8.9   4.9
 15500  -2.8  27.0  230  22 11   8.7   4.8 |  -2.4  27.7  210  29 15   8.6   4.7
 15000  -1.5  29.3  225  20 10   8.7   4.8 |  -1.2  29.8  210  28 14   8.3   4.6
 14500  -0.2  31.6  220  18  9   8.9   4.9 |   0.0  32.0  210  26 14   8.3   4.6
 14000   1.2  34.2  220  16  8   9.6   5.2 |   1.3  34.3  205  24 12   8.5   4.7
 13500   2.6  36.7  215  15  8   9.5   5.2 |   2.5  36.5  200  22 11   8.5   4.7
 13000   4.0  39.2  210  13  7   9.2   5.1 |   3.8  38.8  200  21 11   9.4   5.2
 12500   5.3  41.5  210  12  6   9.2   5.1 |   5.2  41.4  195  20 10   9.3   5.1
 12000   6.7  44.1  205  11  5   9.4   5.1 |   6.6  43.9  195  19 10   9.8   5.4
 11500   8.1  46.6  200   9  4   9.5   5.2 |   8.1  46.6  190  17  9   9.9   5.4
 11000   9.4  48.9  190   7  3   7.8   4.3 |   9.4  48.9  190  16  8   8.2   4.5
 10500  10.5  50.9  180   5  2   7.7   4.2 |  10.6  51.1  190  14  7   8.9   4.9
 10250  11.2  52.2  175   4  2  10.7   5.9 |  11.4  52.5  185  13  7  11.1   6.1
 10000  12.0  53.6  165   3  1  10.4   5.7 |  12.2  54.0  185  12  6   9.8   5.4
  9750  12.6  54.7  155   2  1   7.8   4.3 |  12.8  55.0  180  11  6   8.1   4.4
  9500  13.3  55.9  135   1  1   8.5   4.7 |  13.4  56.1  180  10  5   8.6   4.7
  9250  13.9  57.0  100   1  1   8.1   4.5 |  14.0  57.2  175   9  5   8.4   4.6
  9000  14.5  58.1  085   1  0   8.1   4.4 |  14.6  58.3  175   8  4   9.0   4.9
  8750  15.1  59.2  060   1  0   8.2   4.5 |  15.3  59.5  170   7  4   9.5   5.2
  8500  15.7  60.3  035   1  0   8.1   4.4 |  15.9  60.6  170   6  3   9.4   5.2
  8250  16.3  61.3  020   1  1   8.7   4.8 |  16.6  61.9  165   5  3   9.7   5.3
  8000  17.0  62.6  360   1  0   8.2   4.5 |  17.3  63.1  165   4  2   9.6   5.3
  7750  17.5  63.5  330   1  0   7.1   3.9 |  18.0  64.4  165   4  2   9.1   5.0
  7500  18.0  64.4  300   1  0   6.9   3.8 |  18.7  65.7  165   4  2   9.2   5.1
  7250  18.4  65.1  280   1  1   5.3   2.9 |  19.4  66.9  165   4  2  10.5   5.8
  7000  18.7  65.7  270   2  1   3.9   2.2 |  20.2  68.4  165   4  2  11.0   6.0
  6750  19.0  66.2  265   3  1   4.5   2.5 |  21.0  69.8  165   3  2   9.4   5.2
  6500  19.3  66.7  265   3  2   0.8   0.4 |  21.7  71.1  165   3  2   9.6   5.2
  6250  19.0  66.2  265   3  2  -4.4  -2.4 |  22.5  72.5  165   3  1  10.8   5.9
  6000  18.6  65.5  265   4  2  -5.5  -3.0 |  23.3  73.9  165   3  1  11.4   6.3
  5750  18.1  64.6  265   3  2  -1.8  -1.0 |  24.1  75.4  165   2  1   9.9   5.4
  5500  18.3  64.9  260   3  2  11.5   6.3 |  24.9  76.8  165   2  1  15.1   8.3

           05/17/2018 at 1500 MDT          |       05/17/2018 at 1800 MDT
                                           |
K index... +6.3  LI... +0.4                | K index... +10.5  LI... +0.4
CAPE... +0.6  CIN... -0.1                  | CAPE... +8.6  CIN... -51.6
                                           |
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 -57.6 -71.7  260  27 14   2.3   1.3 | -57.0 -70.6  255  14  7   3.0   1.7
 45000 -54.9 -66.8  260  39 20  -2.4  -1.3 | -53.3 -63.9  260  19 10  -2.2  -1.2
 40000 -58.5 -73.3  250  54 28  -2.7  -1.5 | -56.6 -69.9  250  48 25  -2.3  -1.2
 38000 -56.5 -69.7  245  53 27   4.6   2.5 | -55.3 -67.5  250  49 25   3.4   1.9
 36000 -53.8 -64.8  245  52 27   4.6   2.5 | -53.2 -63.8  245  48 25   3.4   1.9
 34000 -50.0 -58.0  240  50 26   8.3   4.6 | -50.0 -58.0  245  45 23   8.2   4.5
 32000 -45.0 -49.0  240  47 24   8.3   4.6 | -44.5 -48.1  245  42 21   8.2   4.5
 30000 -39.4 -38.9  235  44 22   8.4   4.6 | -39.4 -38.9  245  39 20   8.6   4.7
 29000 -36.9 -34.4  235  42 22   8.4   4.6 | -36.8 -34.2  250  37 19   8.6   4.7
 28000 -34.4 -29.9  235  41 21   8.4   4.6 | -34.3 -29.7  250  36 18   8.6   4.7
 27000 -31.9 -25.4  235  40 21   8.3   4.6 | -31.8 -25.2  245  35 18   8.2   4.5
 26000 -29.4 -20.9  235  39 20   8.3   4.6 | -29.3 -20.7  240  34 17   8.2   4.5
 25000 -26.9 -16.4  235  37 19   8.3   4.6 | -26.9 -16.4  240  33 17   8.2   4.5
 24000 -24.4 -11.9  235  35 18   8.2   4.5 | -24.5 -12.1  235  32 16   7.4   4.1
 23000 -22.0  -7.6  235  32 17   8.2   4.5 | -22.3  -8.1  225  30 16   7.5   4.1
 22000 -19.5  -3.1  235  30 15   8.2   4.5 | -20.1  -4.2  215  29 15   7.6   4.1
 21000 -17.1   1.2  230  27 14   8.3   4.6 | -17.7   0.1  210  29 15   9.1   5.0
 20000 -14.6   5.7  220  24 13   8.3   4.6 | -15.0   5.0  205  28 14   9.2   5.0
 19500 -13.3   8.1  215  23 12   8.4   4.6 | -13.6   7.5  200  28 14   9.2   5.0
 19000 -12.1  10.2  210  23 12   8.4   4.6 | -12.2  10.0  200  27 14   9.2   5.1
 18500 -10.8  12.6  205  22 11   8.7   4.8 | -10.8  12.6  200  27 14   9.6   5.3
 18000  -9.5  14.9  200  22 11   8.7   4.8 |  -9.4  15.1  195  27 14   9.6   5.3
 17500  -8.2  17.2  200  22 11   8.9   4.9 |  -8.0  17.6  195  26 13   9.5   5.2
 17000  -6.9  19.6  195  21 11   9.0   4.9 |  -6.5  20.3  195  25 13   9.4   5.2
 16500  -5.6  21.9  195  21 11   9.1   5.0 |  -4.4  24.1  195  24 13   9.4   5.2
 16000  -4.2  24.4  190  20 10   9.3   5.1 |  -3.0  26.6  190  24 12   9.4   5.2
 15500  -2.2  28.0  190  20 10   9.4   5.1 |  -1.6  29.1  190  23 12   9.5   5.2
 15000  -0.7  30.7  190  19 10   9.5   5.2 |  -0.2  31.6  190  22 12   9.7   5.3
 14500   0.7  33.3  190  19 10   9.5   5.2 |   1.3  34.3  190  22 11   9.7   5.3
 14000   2.1  35.8  190  18  9   9.7   5.3 |   2.7  36.9  190  21 11   9.6   5.3
 13500   3.6  38.5  190  17  9   9.7   5.3 |   4.2  39.6  190  20 10   9.7   5.3
 13000   5.0  41.0  190  16  8   9.9   5.5 |   5.6  42.1  185  19 10   9.4   5.1
 12500   6.5  43.7  190  16  8  10.0   5.5 |   7.0  44.6  185  17  9   9.4   5.2
 12000   7.9  46.2  190  15  8   9.4   5.2 |   8.4  47.1  185  16  8   9.0   5.0
 11500   9.4  48.9  190  14  7   9.5   5.2 |   9.7  49.5  185  14  7   9.0   4.9
 11000  10.7  51.3  195  13  7   8.7   4.8 |  11.0  51.8  185  11  6   8.2   4.5
 10500  12.0  53.6  195  13  7   9.4   5.2 |  12.2  54.0  185   9  5   8.1   4.4
 10250  12.8  55.0  195  13  6  11.8   6.5 |  12.9  55.2  185   7  4   9.7   5.3
 10000  13.7  56.7  195  12  6  11.0   6.0 |  13.6  56.5  185   6  3   8.9   4.9
  9750  14.4  57.9  195  12  6   9.8   5.4 |  14.2  57.6  190   4  2   7.3   4.0
  9500  15.2  59.4  200  12  6  10.3   5.7 |  14.7  58.5  205   3  1   7.8   4.3
  9250  15.9  60.6  200  12  6   9.3   5.1 |  15.3  59.5  240   2  1   7.3   4.0
  9000  16.6  61.9  200  12  6   9.1   5.0 |  15.8  60.4  290   2  1   7.0   3.8
  8750  17.3  63.1  200  12  6  10.0   5.5 |  16.3  61.3  315   3  2   7.1   3.9
  8500  18.0  64.4  200  11  6   9.1   5.0 |  16.8  62.2  320   5  2   7.0   3.8
  8250  18.8  65.8  200  11  6  11.6   6.4 |  17.4  63.3  325   6  3   7.4   4.0
  8000  19.7  67.5  205  11  6  11.2   6.1 |  17.9  64.2  325   9  5   6.9   3.8
  7750  20.4  68.7  205  11  6   8.6   4.7 |  18.4  65.1  325  10  5   6.2   3.4
  7500  21.0  69.8  205  11  6   8.9   4.9 |  18.8  65.8  320  12  6   6.0   3.3
  7250  21.7  71.1  205  11  5  10.3   5.6 |  19.3  66.7  320  13  7   7.4   4.0
  7000  22.6  72.7  205  11  5  11.3   6.2 |  19.9  67.8  320  15  8   9.2   5.0
  6750  23.4  74.1  205  10  5   9.5   5.2 |  20.6  69.1  320  16  8   9.1   5.0
  6500  24.0  75.2  210  10  5   9.5   5.2 |  21.2  70.2  315  16  8   9.1   5.0
  6250  24.8  76.6  210  10  5  10.9   6.0 |  21.9  71.4  315  17  9  10.3   5.6
  6000  25.7  78.3  210  10  5  12.0   6.6 |  22.7  72.9  315  16  8  11.4   6.2
  5750  26.5  79.7  210   9  5  10.2   5.6 |  23.5  74.3  320  16  8  10.1   5.5
  5500  27.3  81.1  215   9  4  14.6   8.0 |  24.3  75.7  320  15  8  11.7   6.4
________________________________________________________________________________

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 old Stapleton
Airport site in Denver, Colorado at

                   North Latitude:  39 deg 46 min 5.016 sec
                   West Longitude: 104 deg 52 min 9.984 sec
                   Elevation: 5285 feet (1611 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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