Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 281224
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0624 MDT Thursday, April 28, 2016

This forecast is for Thursday, April 28, 2016:

If the trigger temperature of 44.5 F/6.9 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 9457 ft MSL (4172 ft AGL)

Forecast maximum temperature................... 46.0 F/8.2 C
Time of trigger temperature.................... 1330 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8494 ft MSL (3209 ft AGL)
Thermal soaring outlook for Friday 04/29....... Poor

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 14374 ft MSL (9089 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 23462 ft MSL (18177 ft AGL)
Wave soaring outlook for Friday 04/29.......... Poor

Remarks... Rain and snow will spread over the area today and tonight

Sunrise/Sunset.................... 06:03:10 / 19:50:22 MDT
Total possible sunshine........... 13 hr 47 min 12 sec (827 min 12 sec)
Altitude of sun at 12:56:56 MDT... 64.69 degrees

Upper air data from rawinsonde observation taken on 04/28/2016 at 0600 MDT

Freezing level.................. 6265 ft MSL (980 ft AGL)
Convective condensation level... 13707 ft MSL (8422 ft AGL)
Lifted condensation level....... 10650 ft MSL (5364 ft AGL)
Lifted index.................... +9.0
K index......................... +14.8

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  -54.5 -66.1   235   32   16  -8.7  -4.8  110.3 230.5    58.4      M    M
 45000  -55.9 -68.6   240   42   22   6.2   3.4   83.0 181.4    45.9      M    M
 40000  -58.7 -73.7   230   37   19   2.6   1.4   54.4 129.9    30.5      M    M
 38000  -57.5 -71.5   235   62   32  -0.3  -0.2   47.4 117.4    26.7      M    M
 36000  -56.6 -69.9   235   63   32   5.0   2.7   40.3 104.5    22.5      M    M
 34000  -53.6 -64.5   240   80   41   5.1   2.8   36.2  97.2    20.2      M    M
 32000  -52.1 -61.8   240   65   33   9.0   5.0   30.2  86.3    16.3      M    M
 30000  -47.0 -52.6   240   49   25   9.0   4.9   29.2  84.6    16.0      M    M
 29000  -44.3 -47.7   240   45   23   8.9   4.9   28.7  83.6    15.8      M    M
 28000  -41.0 -41.8   240   41   21   8.9   4.9   28.1  82.7    15.7      M    M
 27000  -38.3 -36.9   240   37   19   8.9   4.9   27.9  82.2    15.7      M    M
 26000  -35.7 -32.3   240   33   17   8.9   4.9   27.7  81.9    15.7      M    M
 25000  -33.0 -27.4   240   29   15   8.9   4.9   27.6  81.7    15.8      M    M
 24000  -30.4 -22.7   235   27   14   7.6   4.2   27.2  80.9    15.6      M    M
 23000  -28.5 -19.3   235   29   15   6.9   3.8   25.9  78.6    14.8      M    M
 22000  -26.2 -15.2   240   28   15   8.9   4.9   25.2  77.4    14.3      M    M
 21000  -23.7 -10.7   240   28   15   8.3   4.6   24.8  76.6    14.1      M    M
 20000  -21.2  -6.2   245   28   14   8.5   4.7   24.3  75.7    13.9      M    M
 19500  -20.0  -4.0   250   28   15   6.4   3.5   23.9  75.1    13.6      M    M
 19000  -19.1  -2.4   250   28   15   6.1   3.4   23.3  73.9    13.1      M    M
 18500  -18.2  -0.8   255   29   15   6.2   3.4   22.6  72.8    12.6      M    M
 18000  -17.2   1.0   255   29   15   8.0   4.4   22.2  71.9    12.3      M    M
 17500  -16.0   3.2   255   29   15   7.8   4.3   21.8  71.3    12.1      M    M
 17000  -14.9   5.2   250   29   15   7.8   4.3   21.5  70.7    11.8      M    M
 16500  -13.7   7.3   250   29   15   7.8   4.3   21.2  70.2    11.6      M    M
 16000  -12.5   9.5   250   29   15   7.8   4.3   20.9  69.7    11.4      M    M
 15500  -11.4  11.5   250   28   14   7.8   4.3   20.6  69.1    11.1      M    M
 15000  -10.2  13.6   250   26   13   7.5   4.1   20.2  68.4    10.9      M    M
 14500   -9.1  15.6   245   24   12   2.4   1.3   19.9  67.9    10.6      M    M
 14000  -10.2  13.6   245   22   11   9.0   4.9   16.4  61.5     7.4      M    M
 13500   -8.8  16.2   240   21   11   9.2   5.0   16.3  61.3     7.4      M    M
 13000   -7.4  18.7   235   20   10   8.2   4.5   16.2  61.2     7.3      M    M
 12500   -6.7  19.9   235   19   10   3.4   1.9   15.5  59.8     6.6      M    M
 12000   -6.2  20.8   230   18    9   3.7   2.0   14.5  58.1     5.7      M    M
 11500   -5.7  21.7   220   18    9   4.0   2.2   13.5  56.4     4.8      M    M
 11000   -5.1  22.8   210   18    9   4.0   2.2   12.6  54.7     3.9      M    M
 10500   -4.5  23.9   205   18    9   3.8   2.1   11.7  53.1     3.1      M    M
 10250   -4.3  24.3   200   18    9   2.7   1.5   11.2  52.2     2.6      M    M
 10000   -4.1  24.6   195   19   10   0.5   0.3   10.6  51.0     2.0      M    M
  9750   -4.2  24.4   195   17    9  -4.2  -2.3    9.7  49.4     1.2      M    M
  9500   -4.7  23.5   195   13    7  -7.6  -4.2    8.4  47.2     0.0      M    M
  9250   -5.1  22.8   200   10    5  -3.8  -2.1    7.2  44.9    -1.2    280  1.4
  9000   -5.2  22.6   200    7    3   1.4   0.8    6.3  43.4    -1.9    274  1.4
  8750   -5.0  23.0   185    5    3   2.3   1.3    5.8  42.4    -2.5    262  1.3
  8500   -4.8  23.4   160    4    2   2.0   1.1    5.2  41.3    -3.0    249  1.3
  8250   -4.6  23.7   125    4    2   4.5   2.5    4.6  40.4    -3.5    235  1.2
  8000   -4.2  24.4   100    5    3   6.3   3.4    4.4  39.8    -3.8    214  1.1
  7750   -3.7  25.3   100    4    2   5.9   3.2    4.1  39.3    -4.1    194  1.0
  7500   -3.3  26.1   105    4    2   5.7   3.1    3.8  38.8    -4.4    174  0.9
  7250   -2.9  26.8   105    3    2   6.9   3.8    3.5  38.3    -4.7    153  0.8
  7000   -2.2  28.0   110    3    2   9.5   5.2    3.4  38.1    -4.9    127  0.6
  6750   -1.5  29.3   110    4    2  10.1   5.5    3.4  38.1    -4.9     97  0.5
  6500   -0.8  30.6   110    5    3  10.0   5.5    3.4  38.1    -4.8     67  0.3
  6250   -0.0  32.0   110    6    3  10.0   5.5    3.4  38.2    -4.8     38  0.2
  6000    0.7  33.3   110    7    4  10.0   5.5    3.5  38.2    -4.8      8  0.0
  5750    1.5  34.7   105    7    3   9.8   5.4    3.5  38.3    -4.8      M    M
  5500    2.2  36.0   105    6    3  10.2   5.6    3.5  38.3    -4.8      M    M

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

           04/28/2016 at 0900 MDT          |       04/28/2016 at 1200 MDT
                                           |
K index... +15.3  LI... +4.7               | K index... +17.8  LI... +4.8
CAPE... 0.0  CIN... -0.5                   | CAPE... 0.0  CIN... -1.4
                                           |
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 -56.1 -69.0  235  24 12   1.1   0.6 | -55.5 -67.9  235  22 11   0.9   0.5
 45000 -54.5 -66.1  235  28 15   1.2   0.7 | -54.2 -65.6  235  27 14   0.9   0.5
 40000 -55.8 -68.4  235  44 23  -1.0  -0.6 | -54.7 -66.5  235  46 24  -0.4  -0.2
 38000 -55.8 -68.4  230  49 25   1.7   0.9 | -54.7 -66.5  230  52 27   0.9   0.5
 36000 -54.8 -66.6  230  54 28   1.7   0.9 | -54.1 -65.4  230  55 28   0.9   0.5
 34000 -53.8 -64.8  230  59 30   3.7   2.0 | -53.6 -64.5  225  58 30   2.7   1.5
 32000 -50.6 -59.1  230  48 25   5.4   3.0 | -50.7 -59.3  225  48 25   4.8   2.6
 30000 -47.3 -53.1  235  38 20   7.6   4.2 | -47.3 -53.1  220  38 20   8.0   4.4
 29000 -44.1 -47.4  230  34 18   8.7   4.7 | -44.9 -48.8  220  35 18   7.7   4.2
 28000 -41.5 -42.7  230  31 16   8.7   4.7 | -42.6 -44.7  215  31 16   7.7   4.2
 27000 -38.9 -38.0  230  28 14   8.6   4.7 | -40.3 -40.5  210  28 15   7.9   4.3
 26000 -36.3 -33.3  225  27 14   8.5   4.7 | -37.6 -35.7  210  29 15   9.4   5.2
 25000 -33.8 -28.8  220  26 13   8.5   4.7 | -34.8 -30.6  205  30 15   9.4   5.2
 24000 -31.3 -24.3  220  25 13   8.6   4.7 | -32.0 -25.6  205  31 16   9.5   5.2
 23000 -28.8 -19.8  215  24 13   8.1   4.5 | -29.3 -20.7  205  31 16   9.1   5.0
 22000 -26.4 -15.5  210  24 12   8.2   4.5 | -26.6 -15.9  205  31 16   9.1   5.0
 21000 -24.0 -11.2  210  24 12   8.1   4.4 | -23.9 -11.0  205  32 16   8.7   4.8
 20000 -21.7  -7.1  215  25 13   7.7   4.2 | -21.5  -6.7  205  32 16   7.8   4.3
 19500 -20.5  -4.9  215  26 13   7.7   4.2 | -20.4  -4.7  210  32 17   7.8   4.3
 19000 -19.4  -2.9  215  26 14   7.7   4.2 | -19.2  -2.6  210  32 17   7.8   4.3
 18500 -18.3  -0.9  220  27 14   7.7   4.2 | -18.1  -0.6  210  33 17   7.8   4.3
 18000 -17.1   1.2  220  29 15   7.7   4.2 | -17.0   1.4  210  32 17   6.8   3.8
 17500 -16.0   3.2  225  30 16   7.8   4.3 | -16.0   3.2  210  32 17   6.9   3.8
 17000 -14.9   5.2  225  32 17   7.6   4.2 | -15.0   5.0  215  32 16   6.7   3.7
 16500 -13.7   7.3  225  33 17   7.6   4.2 | -14.0   6.8  215  30 16   6.7   3.7
 16000 -12.6   9.3  225  35 18   7.4   4.1 | -13.1   8.4  220  29 15   6.6   3.6
 15500 -11.1  12.0  225  35 18   6.8   3.7 | -11.6  11.1  220  28 14   6.3   3.5
 15000 -10.1  13.8  225  35 18   6.4   3.5 | -10.7  12.7  225  28 14   6.5   3.5
 14500  -9.2  15.4  225  33 17   6.1   3.3 |  -9.8  14.4  225  28 14   6.5   3.6
 14000  -8.4  16.9  225  32 16   5.6   3.1 |  -8.8  16.2  225  28 15   6.2   3.4
 13500  -7.7  18.1  225  30 16   4.3   2.4 |  -8.0  17.6  225  28 15   5.2   2.8
 13000  -7.1  19.2  220  28 15   4.1   2.2 |  -7.2  19.0  225  28 15   4.7   2.6
 12500  -6.7  19.9  220  26 14   1.3   0.7 |  -6.8  19.8  220  27 14   1.8   1.0
 12000  -6.5  20.3  215  25 13   1.4   0.7 |  -6.5  20.3  215  25 13   1.9   1.0
 11500  -6.5  20.3  210  23 12  -0.7  -0.4 |  -6.4  20.5  210  24 12   0.3   0.2
 11000  -6.6  20.1  205  22 12  -0.3  -0.2 |  -6.4  20.5  200  24 13   0.8   0.4
 10500  -6.3  20.7  200  22 11   2.9   1.6 |  -6.0  21.2  195  24 12   3.6   2.0
 10250  -6.1  21.0  195  22 11   1.8   1.0 |  -5.7  21.7  190  24 13   2.9   1.6
 10000  -6.0  21.2  190  22 11   4.8   2.6 |  -5.5  22.1  185  25 13   4.8   2.6
  9750  -5.5  22.1  185  21 11   5.6   3.1 |  -5.1  22.8  180  23 12   4.8   2.7
  9500  -5.2  22.6  185  19 10   3.3   1.8 |  -4.8  23.4  175  21 11   3.1   1.7
  9250  -4.9  23.2  180  18  9   4.2   2.3 |  -4.6  23.7  165  19 10   3.5   1.9
  9000  -4.7  23.5  175  16  8   3.0   1.6 |  -4.3  24.3  160  17  9   3.8   2.1
  8750  -4.5  23.9  170  15  8   1.1   0.6 |  -4.0  24.8  150  16  8   4.8   2.7
  8500  -4.5  23.9  160  14  7   0.7   0.4 |  -3.7  25.3  140  15  8   5.0   2.7
  8250  -4.4  24.1  145  13  7   1.0   0.5 |  -3.3  26.1  130  14  7   5.2   2.8
  8000  -4.3  24.3  135  12  6   1.5   0.8 |  -2.9  26.8  120  14  7   6.4   3.5
  7750  -4.1  24.6  120  13  6   3.1   1.7 |  -2.4  27.7  110  13  6   7.3   4.0
  7500  -3.9  25.0  115  13  6   3.2   1.8 |  -1.9  28.6  100  12  6   6.8   3.8
  7250  -3.6  25.5  105  13  7   5.7   3.1 |  -1.4  29.5  090  11  6   7.8   4.3
  7000  -3.0  26.6  105  12  6   9.0   5.0 |  -0.7  30.7  085  10  5   9.0   4.9
  6750  -2.4  27.7  100  11  6   9.0   5.0 |  -0.1  31.8  080   9  5   8.7   4.8
  6500  -1.7  28.9  095  10  5   9.7   5.3 |   0.5  32.9  075   9  5   9.1   5.0
  6250  -1.0  30.2  090   9  5  10.4   5.7 |   1.3  34.3  075   9  4  10.7   5.9
  6000  -0.2  31.6  090   9  4  11.0   6.0 |   2.1  35.8  070   8  4  11.3   6.2
  5750   0.6  33.1  090   8  4  10.2   5.6 |   2.9  37.2  070   8  4  11.1   6.1
  5500   1.4  34.5  090   8  4  11.7   6.4 |   3.9  39.0  070   8  4  16.2   8.9

           04/28/2016 at 1500 MDT          |       04/28/2016 at 1800 MDT
                                           |
K index... +15.9  LI... +3.0               | K index... +19.2  LI... +1.6
CAPE... +37.6  CIN... -0.2                 | CAPE... +10.0  CIN... -1.7
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -55.5 -67.9  245  20 10   0.6   0.3 | -55.7 -68.3  240  18  9   1.1   0.6
 45000 -54.5 -66.1  245  25 13   0.5   0.3 | -53.9 -65.0  235  21 11   0.9   0.5
 40000 -54.5 -66.1  235  49 25  -0.0  -0.0 | -53.9 -65.0  235  43 22   0.0   0.0
 38000 -54.5 -66.1  230  56 29   0.4   0.2 | -54.0 -65.2  235  52 27  -0.5  -0.3
 36000 -54.2 -65.6  230  56 29   0.4   0.2 | -54.3 -65.7  235  58 30  -0.5  -0.3
 34000 -53.9 -65.0  225  57 29   2.5   1.4 | -54.6 -66.3  235  65 34   1.6   0.9
 32000 -50.8 -59.4  225  50 25   5.3   2.9 | -51.7 -61.1  235  56 29   4.9   2.7
 30000 -47.1 -52.8  230  42 21   8.0   4.4 | -48.0 -54.4  230  45 23  10.1   5.5
 29000 -44.7 -48.5  225  39 20   7.8   4.3 | -45.2 -49.4  230  40 21   9.6   5.3
 28000 -42.4 -44.3  225  37 19   7.8   4.3 | -42.3 -44.1  225  36 19   9.6   5.3
 27000 -40.1 -40.2  220  34 18   7.8   4.3 | -39.4 -38.9  225  32 17   9.5   5.2
 26000 -37.5 -35.5  220  34 17   8.9   4.9 | -36.8 -34.2  225  29 15   8.5   4.7
 25000 -34.8 -30.6  220  34 17   8.9   4.9 | -34.3 -29.7  230  26 13   8.5   4.7
 24000 -32.1 -25.8  225  34 17   9.0   4.9 | -31.7 -25.1  230  23 12   8.7   4.8
 23000 -29.5 -21.1  225  33 17   8.6   4.7 | -29.4 -20.9  235  21 11   7.4   4.1
 22000 -27.0 -16.6  225  33 17   8.6   4.7 | -27.2 -17.0  230  18  9   7.4   4.1
 21000 -24.4 -11.9  225  33 17   8.5   4.7 | -25.0 -13.0  230  15  8   7.7   4.2
 20000 -22.0  -7.6  220  32 16   8.2   4.5 | -22.5  -8.5  235  17  9   8.5   4.7
 19500 -20.7  -5.3  220  31 16   8.2   4.5 | -21.3  -6.3  235  18  9   8.5   4.7
 19000 -19.5  -3.1  220  31 16   8.2   4.5 | -20.0  -4.0  240  20 10   8.5   4.7
 18500 -18.3  -0.9  220  30 16   8.2   4.5 | -18.7  -1.7  240  21 11   8.4   4.6
 18000 -17.1   1.2  220  30 16   7.5   4.1 | -17.6   0.3  240  21 11   7.1   3.9
 17500 -16.0   3.2  220  31 16   7.6   4.2 | -16.6   2.1  235  20 10   7.1   3.9
 17000 -14.9   5.2  225  31 16   7.3   4.0 | -15.5   4.1  230  20 10   7.7   4.2
 16500 -13.9   7.0  225  30 15   7.2   4.0 | -13.7   7.3  230  21 11   7.8   4.3
 16000 -12.3   9.9  225  28 15   7.0   3.9 | -12.6   9.3  225  21 11   7.8   4.3
 15500 -11.2  11.8  225  27 14   7.0   3.9 | -11.4  11.5  225  21 11   7.8   4.3
 15000 -10.2  13.6  225  26 14   6.8   3.7 | -10.3  13.5  220  21 11   7.2   4.0
 14500  -9.2  15.4  230  28 14   6.6   3.6 |  -9.3  15.3  220  21 11   6.9   3.8
 14000  -8.3  17.1  235  29 15   5.8   3.2 |  -8.3  17.1  215  22 11   6.3   3.4
 13500  -7.7  18.1  230  28 15   3.8   2.1 |  -7.5  18.5  215  21 11   5.2   2.9
 13000  -7.1  19.2  230  27 14   3.5   1.9 |  -6.7  19.9  210  21 11   4.5   2.5
 12500  -6.9  19.6  225  25 13   1.0   0.6 |  -6.4  20.5  205  19 10   2.0   1.1
 12000  -6.7  19.9  215  23 12   1.4   0.8 |  -6.1  21.0  200  16  8   2.6   1.4
 11500  -6.4  20.5  210  20 11   3.8   2.1 |  -5.5  22.1  185  13  7   5.0   2.8
 11000  -5.9  21.4  195  18  9   4.0   2.2 |  -4.9  23.2  165  12  6   5.3   2.9
 10500  -5.1  22.8  175  16  8   6.5   3.6 |  -3.9  25.0  155  12  6   7.3   4.0
 10250  -4.6  23.7  170  16  8   5.8   3.2 |  -3.4  25.9  150  13  6   6.4   3.5
 10000  -4.2  24.4  160  16  8   8.6   4.7 |  -2.9  26.8  145  13  7   9.5   5.2
  9750  -3.5  25.7  145  15  8   8.7   4.8 |  -2.1  28.2  140  13  7   9.2   5.1
  9500  -3.0  26.6  140  15  8   6.3   3.5 |  -1.7  28.9  135  13  7   5.9   3.2
  9250  -2.5  27.5  130  14  7   7.0   3.8 |  -1.2  29.8  130  12  6   7.0   3.9
  9000  -2.0  28.4  125  14  7   6.8   3.7 |  -0.7  30.7  130  12  6   5.8   3.2
  8750  -1.5  29.3  120  13  7   6.8   3.8 |  -0.3  31.5  125  11  6   4.9   2.7
  8500  -1.0  30.2  110  12  6   6.8   3.7 |   0.0  32.0  120  10  5   5.3   2.9
  8250  -0.5  31.1  105  11  6   6.9   3.8 |   0.4  32.7  110   9  5   4.9   2.7
  8000   0.0  32.0  100  10  5   7.8   4.3 |   0.7  33.3  100   8  4   2.9   1.6
  7750   0.6  33.1  090   9  5   7.9   4.4 |   0.9  33.6  085   7  3   2.0   1.1
  7500   1.2  34.2  090   9  5   7.2   4.0 |   1.0  33.8  070   6  3   2.4   1.3
  7250   1.7  35.1  085   8  4   8.3   4.5 |   1.2  34.2  050   6  3   2.4   1.3
  7000   2.4  36.3  080   8  4   9.7   5.3 |   1.4  34.5  025   6  3   2.6   1.5
  6750   3.1  37.6  075   7  4   8.9   4.9 |   1.6  34.9  005   7  4   2.6   1.4
  6500   3.7  38.7  070   7  3   8.7   4.8 |   1.8  35.2  350   8  4   3.9   2.1
  6250   4.4  39.9  065   6  3  10.5   5.8 |   2.2  36.0  340   9  5   7.8   4.3
  6000   5.3  41.5  065   6  3  11.9   6.5 |   2.9  37.2  335   9  5   9.8   5.4
  5750   6.1  43.0  060   6  3  10.0   5.5 |   3.6  38.5  330   9  5   9.1   5.0
  5500   6.9  44.4  050   5  3  12.2   6.7 |   4.4  39.9  325   9  5  12.2   6.7
________________________________________________________________________________

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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