Soaring Guidance
Issued by NWS Pueblo, CO

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616
UXUS97 KPUB 081237
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0636 MDT Wednesday, October 8, 2025

This forecast is for Villa Grove, CO for Wednesday, October 8, 2025:

If the trigger temperature of 57.9 F/14.4 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 824 ft/min (4.2 m/s)
   Maximum height of thermals.................. 19845 ft MSL (10891 ft AGL)

Forecast maximum temperature................... 70.0 F/21.6 C
Time of trigger temperature.................... 1130 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 17478 ft MSL (8524 ft AGL)
Thermal soaring outlook for Thursday 10/09..... Good

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

Remarks...

Sunrise/Sunset.................... 07:06:20 / 18:35:35 MDT
Total possible sunshine........... 11 hr 29 min 15 sec (689 min 15 sec)
Altitude of sun at 12:50:58 MDT... 45.48 degrees

Upper air data from numerical model forecast valid on 10/08/2025 at 0600 MDT

Freezing level.................. 13818 ft MSL (4864 ft AGL)
Convective condensation level... 16426 ft MSL (7472 ft AGL)
Lifted condensation level....... 18391 ft MSL (9437 ft AGL)
Lifted index.................... -2.6
K index......................... -16.3

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  -63.4 -82.1   270   52   27   3.2   1.7      M     M       M      M    M
 45000  -58.0 -72.4   265   67   34   5.1   2.8      M     M       M      M    M
 40000  -50.4 -58.7   265   71   36   3.5   1.9      M     M       M      M    M
 38000  -48.4 -55.1   265   63   32   3.3   1.8      M     M       M      M    M
 36000  -46.4 -51.5   265   55   28   3.3   1.8      M     M       M      M    M
 34000  -43.5 -46.3   265   47   24   5.6   3.1      M     M       M      M    M
 32000  -39.7 -39.5   270   40   20   5.7   3.1      M     M       M      M    M
 30000  -35.3 -31.5   270   36   18   8.0   4.4   28.8  83.8     6.1      M    M
 29000  -32.9 -27.2   265   35   18   8.0   4.4   28.2  82.7     5.6      M    M
 28000  -30.5 -22.9   265   33   17   8.0   4.4   27.6  81.7     5.3      M    M
 27000  -28.1 -18.6   265   32   16   7.9   4.3   26.8  80.3     4.7      M    M
 26000  -25.7 -14.3   265   30   16   7.9   4.3   26.1  79.0     4.2      M    M
 25000  -23.4 -10.1   265   29   15   7.8   4.3   25.5  77.9     3.7      M    M
 24000  -21.0  -5.8   270   28   14   8.0   4.4   24.8  76.7     3.2      M    M
 23000  -18.6  -1.5   270   27   14   8.0   4.4   24.2  75.6     2.7      M    M
 22000  -16.2   2.8   270   27   14   8.2   4.5   23.7  74.6     2.2      M    M
 21000  -14.2   6.4   270   26   14   6.2   3.4   22.6  72.6     1.3      M    M
 20000  -12.3   9.9   265   26   13   6.2   3.4   21.3  70.4     0.2      M    M
 19500  -11.4  11.5   265   26   13   6.3   3.4   20.8  69.4    -0.3    999  5.1
 19000  -10.5  13.1   265   26   13   5.5   3.0   20.2  68.4    -0.8    957  4.9
 18500   -9.7  14.5   265   27   14   5.3   2.9   19.4  67.0    -1.5    919  4.7
 18000   -8.9  16.0   265   28   14   5.3   2.9   18.7  65.7    -2.2    881  4.5
 17500   -8.1  17.4   265   29   15   5.7   3.1   18.0  64.4    -2.9    841  4.3
 17000   -7.2  19.0   265   29   15   5.6   3.1   17.3  63.2    -3.5    801  4.1
 16500   -6.4  20.5   265   30   15   6.3   3.4   16.7  62.0    -4.1    760  3.9
 16000   -5.4  22.3   265   30   16   6.5   3.6   16.1  61.0    -4.7    718  3.6
 15500   -4.5  23.9   265   30   16   7.1   3.9   15.6  60.1    -5.2    675  3.4
 15000   -3.4  25.9   260   29   15   8.0   4.4   15.3  59.5    -5.6    626  3.2
 14500   -1.6  29.1   260   27   14   9.1   5.0   14.9  58.9    -6.1    552  2.8
 14000   -0.2  31.6   260   26   14   9.9   5.4   14.9  58.9    -6.2    494  2.5
 13500    1.2  34.2   260   26   13   9.7   5.3   15.0  58.9    -6.2    436  2.2
 13000    2.5  36.5   260   25   13   8.1   4.4   14.8  58.7    -6.5    383  1.9
 12500    3.6  38.5   260   25   13   7.3   4.0   14.5  58.2    -6.9    335  1.7
 12000    4.5  40.1   255   24   12   6.2   3.4   14.0  57.2    -7.5    295  1.5
 11750    4.8  40.6   250   24   12   6.4   3.5   13.7  56.7    -7.9    276  1.4
 11500    5.2  41.4   250   24   12   5.0   2.7   13.5  56.2    -8.3    258  1.3
 11250    5.4  41.7   245   24   12   3.0   1.6   13.0  55.4    -8.8    244  1.2
 11000    5.6  42.1   245   23   12   2.7   1.5   12.5  54.4    -9.4    231  1.2
 10750    5.8  42.4   240   23   12   3.7   2.0   11.9  53.5   -10.0    219  1.1
 10500    5.9  42.6   235   23   12   0.0   0.0   11.4  52.6   -10.6    206  1.0
 10250    5.7  42.3   235   22   11  -4.2  -2.3   10.4  50.8   -11.6    205  1.0
 10000    5.4  41.7   230   20   10  -6.0  -3.3    9.4  48.8   -12.6    207  1.1
  9750    5.1  41.2   230   18    9   1.3   0.7    8.3  46.9   -13.7    209  1.1
  9500    5.4  41.7   225   16    8  -4.1  -2.3    7.8  46.0   -14.2    193  1.0
  9250    3.9  39.0   220   11    6 -34.7 -19.1    5.6  42.0   -16.4    230  1.2
  9000    2.4  36.3   220    6    3  23.9  13.1    3.3  37.9   -18.8    270  1.4
  8750      M     M     M    M    M     M     M      M     M       M      M    M
  8500      M     M     M    M    M     M     M      M     M       M      M    M
  8250      M     M     M    M    M     M     M      M     M       M      M    M
  8000      M     M     M    M    M     M     M      M     M       M      M    M

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

           10/08/2025 at 0900 MDT          |       10/08/2025 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +3.4        | CAPE...  +126.8    LI...       +1.1
CINH...     0.0    K Index... -19.6        | CINH...   -38.2    K Index... -14.2
                                           |
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 -63.9 -83.0  270  48 25   3.2   1.7 | -64.7 -84.5  270  46 24   3.3   1.8
 45000 -58.4 -73.1  270  66 34   5.2   2.9 | -58.8 -73.8  270  67 34   5.7   3.1
 40000 -50.3 -58.5  265  67 34   4.2   2.3 | -50.0 -58.0  270  66 34   4.8   2.7
 38000 -47.8 -54.0  265  62 32   4.3   2.3 | -47.1 -52.8  270  64 33   4.9   2.7
 36000 -45.2 -49.4  270  56 29   4.3   2.3 | -44.1 -47.4  270  62 32   4.8   2.6
 34000 -42.6 -44.7  265  47 24   4.3   2.4 | -42.0 -43.6  265  51 26   3.0   1.7
 32000 -40.1 -40.2  260  35 18   4.3   2.4 | -40.2 -40.4  260  38 19   3.1   1.7
 30000 -35.8 -32.4  265  31 16   8.6   4.7 | -36.1 -33.0  255  32 16   8.7   4.8
 29000 -33.2 -27.8  265  31 16   8.6   4.7 | -33.5 -28.3  255  30 16   8.7   4.8
 28000 -30.6 -23.1  270  31 16   8.7   4.8 | -30.2 -22.4  255  29 15   8.3   4.6
 27000 -27.7 -17.9  270  30 15   7.5   4.1 | -27.8 -18.0  260  28 15   8.0   4.4
 26000 -25.5 -13.9  270  29 15   7.5   4.1 | -25.4 -13.7  260  28 14   8.0   4.4
 25000 -23.3  -9.9  265  28 14   7.4   4.1 | -23.0  -9.4  260  28 14   8.0   4.4
 24000 -20.8  -5.4  265  27 14   8.2   4.5 | -20.5  -4.9  265  27 14   8.3   4.6
 23000 -18.4  -1.1  265  26 13   8.2   4.5 | -18.0  -0.4  265  26 13   8.3   4.6
 22000 -15.9   3.4  265  25 13   8.1   4.4 | -15.5   4.1  270  25 13   8.1   4.5
 21000 -13.7   7.3  270  25 13   7.3   4.0 | -13.3   8.1  270  25 13   7.2   3.9
 20000 -11.5  11.3  270  25 13   7.3   4.0 | -11.2  11.8  275  25 13   7.2   4.0
 19500 -10.4  13.3  270  25 13   7.5   4.1 | -10.1  13.8  275  25 13   7.5   4.1
 19000  -9.5  14.9  270  25 13   4.9   2.7 |  -9.2  15.4  275  26 13   4.1   2.2
 18500  -8.8  16.2  275  25 13   4.7   2.6 |  -8.6  16.5  275  26 13   4.0   2.2
 18000  -8.1  17.4  275  26 13   4.4   2.4 |  -8.0  17.6  275  27 14   4.1   2.3
 17500  -7.5  18.5  275  27 14   3.4   1.9 |  -7.4  18.7  275  28 14   4.5   2.5
 17000  -7.0  19.4  275  29 15   3.2   1.8 |  -6.7  19.9  275  30 15   4.2   2.3
 16500  -6.3  20.7  275  31 16   6.6   3.6 |  -5.9  21.4  275  31 16   7.3   4.0
 16000  -5.4  22.3  270  33 17   6.8   3.7 |  -4.9  23.2  270  32 17   7.3   4.0
 15500  -4.4  24.1  270  35 18   8.4   4.6 |  -3.8  25.2  270  33 17   8.1   4.4
 15000  -3.0  26.6  270  35 18   9.2   5.1 |  -2.6  27.3  270  31 16   8.4   4.6
 14500  -1.7  28.9  270  34 18   8.4   4.6 |  -1.4  29.5  265  28 15   7.4   4.1
 14000  -0.5  31.1  265  31 16   8.5   4.7 |  -0.3  31.5  265  26 14   9.1   5.0
 13500   1.4  34.5  265  26 14   9.2   5.0 |   1.6  34.9  260  23 12   8.3   4.5
 13000   2.7  36.9  265  23 12   7.7   4.2 |   2.7  36.9  260  20 10   7.2   4.0
 12500   3.7  38.7  260  21 11   6.8   3.7 |   3.7  38.7  255  17  9   6.1   3.3
 12000   4.6  40.3  260  20 10   6.0   3.3 |   4.4  39.9  250  17  9   4.9   2.7
 11750   5.0  41.0  255  19 10   6.4   3.5 |   4.7  40.5  245  17  9   4.3   2.4
 11500   5.3  41.5  250  19 10   3.9   2.1 |   4.9  40.8  240  17  9   3.5   1.9
 11250   5.4  41.7  250  18  9   1.4   0.8 |   5.1  41.2  235  17  9   2.8   1.6
 11000   5.5  41.9  245  18  9   1.9   1.1 |   5.2  41.4  235  17  9   2.9   1.6
 10750   5.6  42.1  240  18  9   2.4   1.3 |   5.4  41.7  230  18  9   3.7   2.0
 10500   5.6  42.1  240  18  9  -0.9  -0.5 |   5.7  42.3  225  17  9   7.6   4.1
 10250   5.3  41.5  235  18  9  -3.8  -2.1 |   6.4  43.5  225  16  8   9.6   5.3
 10000   5.1  41.2  235  17  9  -3.2  -1.8 |   7.0  44.6  220  15  8   9.2   5.0
  9750   4.8  40.6  230  16  8  -2.7  -1.5 |   7.7  45.9  220  14  7   8.8   4.8
  9500   4.7  40.5  225  15  8   1.7   0.9 |   8.5  47.3  215  13  7  16.5   9.1
  9250   5.0  41.0  225  11  6   6.6   3.6 |  10.3  50.5  215  12  6  30.9  16.9
  9000   5.4  41.7  215   8  4  -1.4  -0.8 |  12.1  53.8  210  11  6   4.9   2.7
  8750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  8500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  8250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  8000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           10/08/2025 at 1500 MDT          |       10/08/2025 at 1800 MDT
                                           |
CAPE...  +502.5    LI...       -1.3        | CAPE...  +194.2    LI...       -2.6
CINH...    -0.6    K Index...  -6.8        | CINH...   -15.7    K Index... +19.6
                                           |
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 -65.2 -85.4  265  46 24   3.5   1.9 | -66.1 -87.0  270  45 23   3.6   2.0
 45000 -58.9 -74.0  275  68 35   6.0   3.3 | -59.4 -74.9  275  67 35   6.8   3.7
 40000 -49.6 -57.3  265  70 36   4.6   2.5 | -49.0 -56.2  270  81 42   4.3   2.4
 38000 -46.9 -52.4  270  67 34   4.6   2.5 | -46.5 -51.7  270  71 36   4.2   2.3
 36000 -44.1 -47.4  270  63 32   4.6   2.5 | -44.0 -47.2  270  61 31   4.2   2.3
 34000 -41.3 -42.3  270  55 28   4.6   2.5 | -40.6 -41.1  275  53 27   6.0   3.3
 32000 -38.6 -37.5  270  46 24   4.7   2.6 | -37.1 -34.8  280  46 24   6.0   3.3
 30000 -34.8 -30.6  270  37 19   7.1   3.9 | -33.4 -28.1  275  39 20   6.1   3.4
 29000 -32.1 -25.8  265  32 17   7.1   3.9 | -31.6 -24.9  270  36 19   6.1   3.4
 28000 -30.0 -22.0  265  28 15   7.9   4.3 | -29.3 -20.7  265  33 17   7.5   4.1
 27000 -27.4 -17.3  265  28 14   8.5   4.7 | -26.7 -16.1  265  31 16   8.5   4.7
 26000 -24.9 -12.8  260  28 14   8.5   4.7 | -24.1 -11.4  265  29 15   8.5   4.7
 25000 -22.3  -8.1  260  27 14   8.5   4.7 | -21.6  -6.9  260  28 14   8.5   4.7
 24000 -20.0  -4.0  255  26 13   7.7   4.2 | -19.2  -2.6  255  26 13   8.0   4.4
 23000 -17.7   0.1  255  25 13   7.7   4.2 | -16.8   1.8  250  25 13   8.0   4.4
 22000 -15.3   4.5  250  24 12   7.6   4.2 | -14.4   6.1  240  24 13   7.3   4.0
 21000 -13.3   8.1  255  23 12   6.7   3.7 | -13.2   8.2  250  24 12   3.5   1.9
 20000 -11.3  11.7  260  22 12   6.7   3.7 | -12.2  10.0  260  24 13   3.8   2.1
 19500 -10.3  13.5  260  22 11   7.2   3.9 | -11.7  10.9  265  25 13   3.8   2.1
 19000  -9.5  14.9  265  23 12   1.7   0.9 | -11.0  12.2  270  25 13   6.4   3.5
 18500  -9.3  15.3  270  26 14   1.8   1.0 | -10.1  13.8  275  25 13   6.6   3.6
 18000  -9.2  15.4  275  30 15   3.7   2.0 |  -9.2  15.4  275  24 13   7.3   4.0
 17500  -8.3  17.1  275  31 16   7.3   4.0 |  -8.0  17.6  275  23 12   8.7   4.8
 17000  -7.3  18.9  275  33 17   7.2   4.0 |  -6.7  19.9  275  21 11   8.8   4.8
 16500  -6.1  21.0  275  32 16   9.0   4.9 |  -5.5  22.1  275  19 10   8.4   4.6
 16000  -4.8  23.4  275  29 15   8.9   4.9 |  -4.3  24.3  275  17  9   8.5   4.7
 15500  -3.5  25.7  270  26 13   8.6   4.7 |  -3.1  26.4  270  15  8   8.4   4.6
 15000  -2.3  27.9  265  23 12   8.5   4.6 |  -1.9  28.6  260  14  7   8.3   4.6
 14500  -1.1  30.0  265  21 11   8.1   4.4 |  -0.6  30.9  255  13  7   7.4   4.1
 14000   0.6  33.1  255  19 10   8.5   4.6 |   1.1  34.0  245  12  6   8.6   4.7
 13500   1.8  35.2  250  18  9   8.2   4.5 |   2.4  36.3  235  12  6   8.7   4.8
 13000   2.9  37.2  245  18  9   8.3   4.5 |   3.6  38.5  230  14  7   7.6   4.2
 12500   4.1  39.4  240  17  9   7.8   4.3 |   4.7  40.5  220  16  8   7.9   4.3
 12000   5.1  41.2  230  15  8   8.1   4.4 |   5.8  42.4  215  17  9   8.0   4.4
 11750   5.7  42.3  230  15  8   9.3   5.1 |   6.4  43.5  215  17  9   7.7   4.2
 11500   6.3  43.3  225  15  7   9.2   5.0 |   7.0  44.6  210  17  9   8.1   4.5
 11250   7.0  44.6  225  14  7   9.3   5.1 |   7.6  45.7  210  17  9   8.8   4.8
 11000   7.7  45.9  225  14  7   8.9   4.9 |   8.2  46.8  210  17  9   8.2   4.5
 10750   8.4  47.1  220  14  7  10.4   5.7 |   8.8  47.8  205  17  9  10.1   5.5
 10500   9.2  48.6  220  14  7  11.5   6.3 |   9.7  49.5  205  17  9  10.9   6.0
 10250  10.1  50.2  220  14  7  10.6   5.8 |  10.4  50.7  205  16  8   9.8   5.4
 10000  10.9  51.6  220  13  7  11.2   6.2 |  11.1  52.0  205  16  8   9.8   5.4
  9750  11.7  53.1  220  13  7   9.6   5.3 |  11.9  53.4  205  15  8  10.4   5.7
  9500  12.5  54.5  220  13  7  15.4   8.5 |  12.7  54.9  205  15  8  10.4   5.7
  9250  14.2  57.6  220  12  6  29.7  16.3 |  13.3  55.9  205  12  6   8.2   4.5
  9000  15.8  60.4  215  11  6   3.1   1.7 |  14.0  57.2  200   9  5  12.7   7.0
  8750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  8500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  8250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  8000     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 Villa Grove, Colorado at:

                   North Latitude:  38 deg 16 min 03 sec
                   West Longitude: 105 deg 53 min 37 sec
                   Elevation: 7986 feet (2434 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.

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