Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 271239
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0639 MDT Wednesday, April 27, 2016

This forecast is for Wednesday, April 27, 2016:

If the trigger temperature of 48.6 F/9.2 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 597 ft/min (3.0 m/s)
   Maximum height of thermals.................. 12817 ft MSL (7532 ft AGL)

Forecast maximum temperature................... 55.0 F/13.2 C
Time of trigger temperature.................... 1115 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................. 9796 ft MSL (4511 ft AGL)
Thermal soaring outlook for Thursday 04/28..... Poor

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 17860 ft MSL (12575 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 18353 ft MSL (13068 ft AGL)
Wave soaring outlook for Thursday 04/28........ Poor

Remarks... None

Sunrise/Sunset.................... 06:04:28 / 19:49:22 MDT
Total possible sunshine........... 13 hr 44 min 54 sec (824 min 54 sec)
Altitude of sun at 12:57:05 MDT... 64.38 degrees

Upper air data from rawinsonde observation taken on 04/27/2016 at 0600 MDT

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 12169 ft MSL (6884 ft AGL)
Lifted condensation level....... 12626 ft MSL (7341 ft AGL)
Lifted index.................... +2.9
K index......................... +10.4

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  -56.1 -69.0   255    8    4   6.3   3.5  106.9 224.4    53.8      M    M
 45000  -51.2 -60.2   285   17    9  -2.8  -1.5   90.3 194.6    47.4      M    M
 40000  -53.1 -63.6   255   16    8   6.2   3.4   64.0 147.2    33.4      M    M
 38000  -51.8 -61.2   295   22   11   1.7   0.9   57.2 134.9    29.7      M    M
 36000  -53.6 -64.5   300   18    9   6.8   3.7   45.9 114.6    22.8      M    M
 34000  -54.0 -65.2   300   25   13  -5.6  -3.0   35.8  96.5    16.3      M    M
 32000  -52.6 -62.7   315   44   23   5.8   3.2   29.6  85.3    12.3      M    M
 30000  -48.3 -54.9   320   40   21   8.4   4.6   27.6  81.7    11.1      M    M
 29000  -45.6 -50.1   320   36   19   8.7   4.8   27.1  80.8    10.9      M    M
 28000  -43.1 -45.6   315   33   17   8.0   4.4   26.7  80.1    10.7      M    M
 27000  -40.7 -41.3   315   29   15   7.8   4.3   25.9  78.6    10.2      M    M
 26000  -38.4 -37.1   310   26   13   7.8   4.3   25.2  77.4     9.8      M    M
 25000  -36.0 -32.8   320   22   11   8.7   4.8   24.5  76.1     9.3      M    M
 24000  -33.4 -28.1   325   22   11   8.7   4.8   24.1  75.3     9.1      M    M
 23000  -30.9 -23.6   330   18    9   8.4   4.6   23.7  74.6     8.8      M    M
 22000  -28.2 -18.8   350   17    9   9.3   5.1   23.4  74.1     8.7      M    M
 21000  -25.5 -13.9   350   16    8   7.8   4.3   23.1  73.5     8.5      M    M
 20000  -23.1  -9.6   335   21   11   7.8   4.3   22.4  72.3     8.1      M    M
 19500  -22.0  -7.6   330   23   12   7.3   4.0   22.1  71.7     7.8      M    M
 19000  -21.0  -5.8   320   26   13   6.4   3.5   21.5  70.7     7.4      M    M
 18500  -20.1  -4.2   320   31   16   6.2   3.4   20.9  69.6     6.9      M    M
 18000  -19.2  -2.6   320   35   18   1.4   0.8   20.3  68.5     6.4      M    M
 17500  -19.2  -2.6   320   33   17   5.5   3.0   18.5  65.3     4.8      M    M
 17000  -18.1  -0.6   310   32   17   8.4   4.6   18.2  64.7     4.6      M    M
 16500  -17.2   1.0   310   31   16   1.3   0.7   16.6  61.9     3.2      M    M
 16000  -16.6   2.1   315   31   16   8.4   4.6   15.7  60.3     2.4      M    M
 15500  -15.4   4.3   320   32   16   8.2   4.5   15.4  59.8     2.2      M    M
 15000  -14.1   6.6   320   32   16   8.2   4.5   15.2  59.3     2.0      M    M
 14500  -12.9   8.8   325   33   17   8.2   4.5   14.9  58.9     1.7      M    M
 14000  -11.8  10.8   325   33   17   6.3   3.5   14.6  58.3     1.5      M    M
 13500  -10.9  12.4   320   33   17   5.7   3.1   13.9  57.0     0.8      M    M
 13000  -10.1  13.8   320   34   17   5.6   3.1   13.2  55.8     0.1      M    M
 12500   -9.3  15.3   315   34   18   5.6   3.1   12.6  54.6    -0.5    567  2.9
 12000   -8.5  16.7   315   35   18   5.5   3.0   11.9  53.5    -1.1    527  2.7
 11500   -7.5  18.5   315   36   18   7.4   4.1   11.4  52.5    -1.6    484  2.5
 11000   -6.5  20.3   315   36   18   7.2   4.0   11.0  51.8    -2.0    437  2.2
 10500   -5.4  22.3   315   35   18   7.2   4.0   10.6  51.0    -2.5    390  2.0
 10250   -4.9  23.2   310   34   18   7.2   3.9   10.4  50.7    -2.7    367  1.9
 10000   -4.3  24.3   310   33   17   7.3   4.0   10.2  50.3    -2.9    344  1.7
  9750   -3.8  25.2   310   33   17   7.0   3.9   10.0  50.0    -3.1    320  1.6
  9500   -3.3  26.1   310   31   16   8.3   4.6    9.8  49.6    -3.3    297  1.5
  9250   -2.7  27.1   305   29   15   3.7   2.0    9.6  49.3    -3.5    273  1.4
  9000   -2.8  27.0   305   27   14  -2.0  -1.1    8.8  47.9    -4.3    267  1.4
  8750   -2.9  26.8   305   24   12   1.3   0.7    8.0  46.4    -5.1    263  1.3
  8500   -2.6  27.3   305   21   11   5.6   3.1    7.5  45.5    -5.6    248  1.3
  8250   -2.2  28.0   305   19   10   6.5   3.6    7.3  45.1    -5.9    226  1.1
  8000   -1.7  28.9   305   16    8   7.2   3.9    7.0  44.6    -6.1    205  1.0
  7750   -1.5  29.3   300   13    7  -8.0  -4.4    6.5  43.7    -6.7    192  1.0
  7500   -2.7  27.1   290   10    5 -14.5  -8.0    4.5  40.1    -8.6    220  1.1
  7250   -3.2  26.2   270    7    4  -1.7  -0.9    3.2  37.8    -9.9    228  1.2
  7000   -3.1  26.4   240    6    3   4.3   2.3    2.6  36.7   -10.6    218  1.1
  6750   -2.7  27.1   240    5    2   6.5   3.6    2.3  36.1   -10.9    197  1.0
  6500   -2.2  28.0   240    3    2   5.9   3.3    2.0  35.6   -11.2    176  0.9
  6250   -1.7  28.9   240    2    1   6.1   3.4    1.8  35.2   -11.5    155  0.8
  6000   -1.3  29.7   000    0    0   6.0   3.3    1.5  34.7   -11.8    134  0.7
  5750   -0.8  30.6   095    1    1   6.1   3.4    1.2  34.2   -12.1    113  0.6
  5500   -0.4  31.3   095    3    1   5.8   3.2    0.9  33.7   -12.4     92  0.5

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

           04/27/2016 at 0900 MDT          |       04/27/2016 at 1200 MDT
                                           |
K index... +13.0  LI... +4.5               | K index... +11.9  LI... +4.7
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... M
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -55.5 -67.9  245  15  8   1.5   0.8 | -56.1 -69.0  250  18  9   1.4   0.8
 45000 -53.2 -63.8  265  20 11   1.6   0.9 | -54.0 -65.2  275  18  9   1.5   0.8
 40000 -52.4 -62.3  285  21 11   0.4   0.2 | -53.7 -64.7  285  25 13   0.1   0.1
 38000 -52.4 -62.3  290  21 11  -0.9  -0.5 | -53.5 -64.3  285  27 14   0.6   0.3
 36000 -52.9 -63.2  305  22 11  -0.9  -0.5 | -53.1 -63.6  290  28 14   0.6   0.3
 34000 -53.5 -64.3  315  24 12  -0.0  -0.0 | -52.8 -63.0  295  29 15   1.9   1.0
 32000 -50.2 -58.4  325  18  9   5.9   3.2 | -49.7 -57.5  285  27 14   5.4   2.9
 30000 -46.7 -52.1  340  12  6   6.4   3.5 | -46.5 -51.7  280  26 14   6.0   3.3
 29000 -44.4 -47.9  335  16  8   7.8   4.3 | -43.8 -46.8  285  24 13   7.2   4.0
 28000 -41.5 -42.7  335  22 11   7.8   4.3 | -41.6 -42.9  290  23 12   7.2   4.0
 27000 -39.2 -38.6  330  26 14   7.8   4.3 | -39.5 -39.1  300  22 11   7.1   3.9
 26000 -37.0 -34.6  330  29 15   7.3   4.0 | -37.1 -34.8  300  23 12   8.1   4.4
 25000 -34.8 -30.6  325  31 16   7.3   4.0 | -34.7 -30.5  305  24 13   8.1   4.4
 24000 -32.6 -26.7  320  34 17   7.3   4.0 | -32.3 -26.1  305  26 13   8.1   4.4
 23000 -30.3 -22.5  320  34 18   8.1   4.4 | -29.8 -21.6  305  27 14   8.4   4.6
 22000 -27.9 -18.2  315  34 18   8.1   4.5 | -27.3 -17.1  300  29 15   8.4   4.6
 21000 -25.4 -13.7  310  34 17   8.4   4.6 | -24.8 -12.6  295  30 15   8.5   4.7
 20000 -23.4 -10.1  310  33 17   6.4   3.5 | -22.6  -8.7  290  29 15   7.2   3.9
 19500 -22.5  -8.5  305  32 17   6.4   3.5 | -21.5  -6.7  290  28 14   7.2   3.9
 19000 -21.5  -6.7  305  32 16   6.4   3.5 | -20.4  -4.7  290  27 14   7.2   3.9
 18500 -20.6  -5.1  305  31 16   6.5   3.6 | -19.4  -2.9  285  26 13   7.4   4.0
 18000 -19.7  -3.5  305  30 16   5.5   3.0 | -18.4  -1.1  285  25 13   5.2   2.9
 17500 -18.9  -2.0  305  30 16   5.4   2.9 | -17.7   0.1  290  25 13   5.2   2.8
 17000 -18.1  -0.6  305  30 15   5.5   3.0 | -16.9   1.6  295  25 13   5.3   2.9
 16500 -17.2   1.0  310  30 15   6.0   3.3 | -16.1   3.0  300  27 14   5.4   2.9
 16000 -16.4   2.5  310  30 16   6.0   3.3 | -15.4   4.3  305  30 15   5.4   3.0
 15500 -15.5   4.1  315  31 16   5.5   3.0 | -14.6   5.7  310  33 17   4.7   2.6
 15000 -14.3   6.3  315  31 16   5.8   3.2 | -13.6   7.5  310  38 19   5.3   2.9
 14500 -13.4   7.9  320  32 16   6.6   3.6 | -12.7   9.1  310  39 20   6.2   3.4
 14000 -12.4   9.7  320  32 17   6.5   3.6 | -11.8  10.8  310  40 20   6.2   3.4
 13500 -11.5  11.3  325  33 17   6.5   3.6 | -10.9  12.4  315  39 20   6.5   3.6
 13000 -10.5  13.1  325  33 17   6.5   3.6 | -10.0  14.0  315  37 19   6.5   3.6
 12500  -9.5  14.9  325  32 17   6.6   3.6 |  -9.0  15.8  315  35 18   7.3   4.0
 12000  -8.6  16.5  330  32 16   6.7   3.7 |  -7.9  17.8  315  32 17   7.3   4.0
 11500  -7.6  18.3  330  30 16   6.3   3.4 |  -6.9  19.6  315  29 15   6.3   3.5
 11000  -6.7  19.9  330  29 15   6.5   3.6 |  -6.0  21.2  315  26 14   6.5   3.5
 10500  -5.9  21.4  330  27 14   4.9   2.7 |  -5.0  23.0  320  24 12   6.4   3.5
 10250  -5.5  22.1  330  26 13   4.5   2.4 |  -4.6  23.7  320  23 12   5.9   3.2
 10000  -5.1  22.8  330  25 13   6.9   3.8 |  -4.1  24.6  325  22 11   8.6   4.7
  9750  -4.5  23.9  325  24 12   7.5   4.1 |  -3.4  25.9  330  21 11   7.9   4.3
  9500  -4.1  24.6  325  23 12   5.4   2.9 |  -3.0  26.6  330  20 10   4.7   2.6
  9250  -3.7  25.3  325  22 11   5.8   3.2 |  -2.6  27.3  335  19 10   5.6   3.1
  9000  -3.3  26.1  325  20 11   6.0   3.3 |  -2.2  28.0  335  18  9   5.2   2.9
  8750  -2.8  27.0  330  19 10   5.0   2.7 |  -1.8  28.8  340  16  8   4.6   2.5
  8500  -2.5  27.5  335  18  9   3.9   2.1 |  -1.5  29.3  345  14  7   4.2   2.3
  8250  -2.2  28.0  340  17  9   4.2   2.3 |  -1.2  29.8  350  13  6   4.3   2.3
  8000  -1.9  28.6  345  16  8   4.1   2.3 |  -0.9  30.4  355  11  6   4.6   2.5
  7750  -1.7  28.9  355  15  8   3.3   1.8 |  -0.5  31.1  360   8  4   6.1   3.4
  7500  -1.5  29.3  360  14  7   2.5   1.4 |  -0.1  31.8  360   7  4   6.6   3.6
  7250  -1.3  29.7  010  14  7   3.2   1.7 |   0.4  32.7  005   6  3   7.3   4.0
  7000  -1.0  30.2  015  13  7   5.0   2.8 |   1.0  33.8  005   6  3  10.0   5.5
  6750  -0.6  30.9  025  11  6   5.8   3.2 |   1.8  35.2  005   6  3  10.2   5.6
  6500  -0.3  31.5  030   9  5   4.4   2.4 |   2.5  36.5  005   6  3   9.1   5.0
  6250   0.1  32.2  040   7  4   8.3   4.5 |   3.2  37.8  005   5  3  10.6   5.8
  6000   0.9  33.6  045   7  4  12.4   6.8 |   4.1  39.4  005   5  3  12.2   6.7
  5750   1.8  35.2  045   6  3   9.8   5.4 |   4.9  40.8  005   5  3  10.3   5.6
  5500   2.5  36.5  045   6  3  12.2   6.7 |   5.7  42.3  005   5  2  14.3   7.9

           04/27/2016 at 1500 MDT          |       04/27/2016 at 1800 MDT
                                           |
K index... +17.0  LI... +2.4               | K index... +15.8  LI... +0.8
CAPE... 0.0  CIN... -0.5                   | CAPE... 0.0  CIN... M
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -56.6 -69.9  250  19 10   0.4   0.2 | -56.3 -69.3  245  17  9   0.0   0.0
 45000 -56.1 -69.0  260  17  9   0.3   0.2 | -56.3 -69.3  255  20 10   0.0   0.0
 40000 -54.4 -65.9  280  25 13   1.2   0.6 | -56.4 -69.5  285  37 19  -0.1  -0.0
 38000 -53.7 -64.7  285  31 16   0.9   0.5 | -55.8 -68.4  290  44 23   2.4   1.3
 36000 -53.1 -63.6  290  42 22   0.9   0.5 | -54.3 -65.7  285  49 25   2.4   1.3
 34000 -52.6 -62.7  290  54 28   3.8   2.1 | -52.8 -63.0  285  53 27   5.1   2.8
 32000 -48.7 -55.7  290  55 28   6.5   3.6 | -48.9 -56.0  285  52 27   6.6   3.6
 30000 -44.7 -48.5  290  56 29   6.9   3.8 | -44.9 -48.8  285  51 26   7.8   4.3
 29000 -42.1 -43.8  290  50 26   7.1   3.9 | -41.8 -43.2  290  50 26   8.3   4.5
 28000 -39.9 -39.8  290  44 23   7.1   3.9 | -39.3 -38.7  290  50 26   8.3   4.5
 27000 -37.8 -36.0  290  39 20   7.2   4.0 | -36.9 -34.4  290  49 25   8.2   4.5
 26000 -35.8 -32.4  290  34 17   6.7   3.6 | -34.6 -30.3  290  46 24   7.3   4.0
 25000 -33.8 -28.8  290  29 15   6.7   3.7 | -32.4 -26.3  290  42 22   7.3   4.0
 24000 -31.8 -25.2  290  24 12   6.6   3.6 | -30.2 -22.4  290  38 20   7.4   4.1
 23000 -29.7 -21.5  290  23 12   7.2   4.0 | -28.3 -18.9  290  36 19   6.2   3.4
 22000 -27.5 -17.5  295  24 12   7.2   4.0 | -26.4 -15.5  290  34 18   6.2   3.4
 21000 -25.4 -13.7  295  25 13   7.2   4.0 | -24.6 -12.3  290  32 17   6.2   3.4
 20000 -23.0  -9.4  290  26 13   8.2   4.5 | -22.6  -8.7  290  32 17   6.9   3.8
 19500 -21.8  -7.2  285  26 14   8.2   4.5 | -21.6  -6.9  290  32 17   6.9   3.8
 19000 -20.6  -5.1  280  27 14   8.2   4.5 | -20.5  -4.9  290  32 17   6.9   3.8
 18500 -19.3  -2.7  280  28 14   8.5   4.7 | -19.5  -3.1  290  32 17   7.0   3.8
 18000 -18.3  -0.9  280  29 15   5.5   3.0 | -18.5  -1.3  290  33 17   6.5   3.5
 17500 -17.5   0.5  290  32 16   5.7   3.1 | -17.6   0.3  290  34 17   6.6   3.6
 17000 -16.6   2.1  295  34 18   5.6   3.1 | -16.6   2.1  285  35 18   6.7   3.7
 16500 -15.9   3.4  300  37 19   5.5   3.0 | -15.6   3.9  285  36 19   6.8   3.7
 16000 -15.1   4.8  300  39 20   5.6   3.1 | -14.7   5.5  285  37 19   7.0   3.8
 15500 -14.1   6.6  300  40 21   6.8   3.8 | -13.0   8.6  285  37 19   7.8   4.3
 15000 -12.7   9.1  300  40 20   7.0   3.8 | -11.8  10.8  285  37 19   8.0   4.4
 14500 -11.6  11.1  300  37 19   7.4   4.1 | -10.6  12.9  285  35 18   8.2   4.5
 14000 -10.5  13.1  300  34 18   7.4   4.1 |  -9.4  15.1  285  34 17   8.1   4.4
 13500  -9.4  15.1  300  32 16   7.6   4.2 |  -8.3  17.1  285  31 16   7.8   4.3
 13000  -8.3  17.1  300  29 15   7.6   4.2 |  -7.1  19.2  285  28 14   7.7   4.2
 12500  -7.2  19.0  300  26 14   7.4   4.0 |  -6.1  21.0  285  24 12   6.8   3.7
 12000  -6.1  21.0  300  24 12   7.4   4.1 |  -5.1  22.8  290  19 10   6.8   3.8
 11500  -5.1  22.8  300  21 11   6.4   3.5 |  -4.3  24.3  295  15  8   5.2   2.8
 11000  -4.2  24.4  305  17  9   6.5   3.6 |  -3.5  25.7  305  10  5   5.3   2.9
 10500  -3.4  25.9  315  14  7   4.5   2.4 |  -2.7  27.1  325   7  4   5.3   2.9
 10250  -3.1  26.4  320  12  6   4.8   2.6 |  -2.3  27.9  335   7  3   5.5   3.0
 10000  -2.7  27.1  325  11  5   6.6   3.6 |  -1.9  28.6  350   6  3   7.0   3.8
  9750  -2.1  28.2  335   9  5   7.1   3.9 |  -1.3  29.7  360   5  3   8.0   4.4
  9500  -1.7  28.9  340   8  4   6.2   3.4 |  -0.7  30.7  005   5  3   7.9   4.3
  9250  -1.2  29.8  345   7  3   6.4   3.5 |  -0.2  31.6  010   6  3   8.2   4.5
  9000  -0.8  30.6  355   6  3   6.5   3.6 |   0.4  32.7  015   6  3   7.3   4.0
  8750  -0.3  31.5  360   5  3   7.2   4.0 |   0.9  33.6  015   6  3   7.7   4.2
  8500   0.3  32.5  360   5  3   7.9   4.3 |   1.6  34.9  015   6  3   9.1   5.0
  8250   0.8  33.4  005   5  3   7.1   3.9 |   2.2  36.0  015   6  3   8.1   4.5
  8000   1.4  34.5  005   5  2   9.5   5.2 |   2.8  37.0  015   6  3  11.0   6.1
  7750   2.2  36.0  005   5  2  10.5   5.8 |   3.7  38.7  015   6  3  11.0   6.1
  7500   2.9  37.2  005   5  2   8.7   4.8 |   4.4  39.9  015   6  3   8.2   4.5
  7250   3.6  38.5  005   5  2   9.6   5.2 |   5.1  41.2  015   6  3   9.4   5.2
  7000   4.3  39.7  005   5  2  11.0   6.0 |   5.8  42.4  015   6  3  10.9   6.0
  6750   5.1  41.2  005   5  2  10.4   5.7 |   6.6  43.9  010   6  3  10.3   5.6
  6500   5.8  42.4  005   5  2   8.7   4.8 |   7.3  45.1  010   6  3   8.6   4.7
  6250   6.5  43.7  360   5  2  10.6   5.8 |   8.0  46.4  010   6  3  10.1   5.6
  6000   7.4  45.3  360   4  2  12.9   7.1 |   8.8  47.8  010   6  3  11.5   6.3
  5750   8.3  46.9  360   4  2  10.1   5.6 |   9.6  49.3  010   6  3  10.3   5.6
  5500   9.1  48.4  355   4  2  12.9   7.1 |  10.4  50.7  010   6  3  11.6   6.3
________________________________________________________________________________

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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