Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 241256
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0556 MST Wednesday, December 24, 2014

This forecast is for Wednesday, December 24, 2014:

If the trigger temperature of 43.2 F/6.2 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 367 ft/min (1.9 m/s)
   Maximum height of thermals.................. 10802 ft MSL (5517 ft AGL)

Forecast maximum temperature................... 49.0 F/9.9 C
Time of trigger temperature.................... 1045 MST
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................. 9329 ft MSL (4043 ft AGL)
Thermal soaring outlook for Thursday 12/25..... Fair

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... Slight improvement
Height of stable layer (12-18K ft MSL)......... 12423 ft MSL (7138 ft AGL)
Weak PVA/NVA (through 1700 MST)................ Weak NVA
Potential height of wave....................... 35067 ft MSL (29782 ft AGL)
Wave soaring outlook for Thursday 12/25........ Fair

Remarks...

Sunrise/Sunset.................... 07:18:22 / 16:40:03 MST
Total possible sunshine........... 9 hr 21 min 40 sec (561 min 40 sec)
Altitude of sun at 11:59:11 MST... 26.90 degrees

Upper air data from rawinsonde observation taken on 12/24/2014 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 15788 ft MSL (10503 ft AGL)
Lifted condensation level....... 12951 ft MSL (7665 ft AGL)
Lifted index.................... +8.3
K index......................... +12.6

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  -57.1 -70.8   335   49   25   1.7   0.9  105.7 222.2    54.9      M    M
 45000  -54.0 -65.2   330   61   32   2.5   1.4   84.9 184.9    46.2      M    M
 40000  -50.6 -59.1   330   70   36  -4.3  -2.3   67.4 153.4    37.9      M    M
 38000  -52.9 -63.2   345   68   35   8.8   4.8   55.0 131.0    30.6      M    M
 36000  -53.9 -65.0   345   93   48  -6.1  -3.3   45.0 112.9    24.5      M    M
 34000  -55.5 -67.9   345  101   52   7.3   4.0   34.3  93.7    17.6      M    M
 32000  -51.2 -60.2   345   96   49   8.5   4.7   32.0  89.7    16.4      M    M
 30000  -45.6 -50.1   350   89   46   7.3   4.0   30.7  87.3    15.9      M    M
 29000  -43.2 -45.8   355   85   44   8.2   4.5   30.0  86.0    15.6      M    M
 28000  -40.8 -41.4   355   80   41   8.2   4.5   29.3  84.8    15.3      M    M
 27000  -38.4 -37.1   360   75   39   6.6   3.6   28.8  83.8    15.0      M    M
 26000  -36.7 -34.1   360   71   37   6.2   3.4   27.2  81.0    14.0      M    M
 25000  -34.7 -30.5   005   67   34   6.4   3.5   26.1  78.9    13.2      M    M
 24000  -32.3 -26.1   010   62   32   8.7   4.8   25.5  77.8    12.9      M    M
 23000  -29.6 -21.3   005   61   31   9.2   5.1   25.1  77.2    12.7      M    M
 22000  -26.9 -16.4   005   60   31   7.9   4.3   24.9  76.7    12.6      M    M
 21000  -24.8 -12.6   005   58   30   7.3   4.0   23.9  75.1    12.0      M    M
 20000  -22.8  -9.0   005   57   29   6.5   3.6   22.9  73.2    11.2      M    M
 19500  -21.8  -7.2   360   57   29   6.9   3.8   22.3  72.2    10.8      M    M
 19000  -20.7  -5.3   360   56   29   7.8   4.3   21.9  71.5    10.5      M    M
 18500  -19.6  -3.3   355   56   29   9.1   5.0   21.5  70.7    10.2      M    M
 18000  -18.2  -0.8   355   56   29   6.1   3.3   21.3  70.4    10.1      M    M
 17500  -17.4   0.7   355   56   29   4.8   2.6   20.5  69.0     9.5      M    M
 17000  -16.9   1.6   355   57   29   3.0   1.6   19.6  67.2     8.7      M    M
 16500  -16.2   2.8   355   57   29   6.4   3.5   18.7  65.7     7.9      M    M
 16000  -15.4   4.3   355   57   29   5.5   3.0   18.0  64.5     7.3      M    M
 15500  -14.3   6.3   355   56   29   9.7   5.3   17.7  63.9     7.0      M    M
 15000  -12.5   9.5   355   54   28   6.2   3.4   17.3  63.1     6.7      M    M
 14500  -11.7  10.9   360   52   27   4.2   2.3   16.6  61.9     6.0      M    M
 14000  -11.1  12.0   360   49   25   4.1   2.2   15.6  60.1     5.2      M    M
 13500  -10.5  13.1   355   46   24   4.6   2.5   14.7  58.4     4.4      M    M
 13000   -9.9  14.2   355   43   22   0.3   0.2   13.7  56.6     3.6      M    M
 12500   -9.9  14.2   350   39   20  -3.5  -1.9   12.0  53.6     2.1      M    M
 12000   -9.6  14.7   345   37   19   9.8   5.4   10.8  51.4     1.0      M    M
 11500   -8.4  16.9   340   38   19   8.2   4.5   10.5  51.0     0.7      M    M
 11000   -7.3  18.9   340   37   19   4.3   2.4   10.2  50.4     0.4      M    M
 10500   -7.0  19.4   340   31   16   3.5   1.9    9.0  48.2    -0.8    349  1.8
 10250   -6.7  19.9   335   28   15   3.8   2.1    8.5  47.4    -1.3    334  1.7
 10000   -6.4  20.5   335   25   13   3.5   1.9    8.1  46.5    -1.7    318  1.6
  9750   -6.2  20.8   335   22   11   2.9   1.6    7.5  45.6    -2.2    303  1.5
  9500   -5.9  21.4   335   18    9   2.8   1.5    7.0  44.6    -2.7    289  1.5
  9250   -5.7  21.7   335   14    7   2.9   1.6    6.5  43.6    -3.2    275  1.4
  9000   -5.5  22.1   335   11    6   2.9   1.6    5.9  42.7    -3.7    261  1.3
  8750   -5.3  22.5   330    9    5   2.8   1.6    5.4  41.7    -4.2    247  1.3
  8500   -5.0  23.0   320    7    4   4.8   2.6    4.9  40.8    -4.7    232  1.2
  8250   -4.6  23.7   310    6    3   6.3   3.5    4.6  40.3    -5.0    211  1.1
  8000   -4.1  24.6   290    5    3   5.9   3.3    4.3  39.8    -5.3    191  1.0
  7750   -3.7  25.3   285    5    3   6.0   3.3    4.0  39.3    -5.6    170  0.9
  7500   -3.3  26.1   280    6    3   6.0   3.3    3.8  38.8    -6.0    150  0.8
  7250   -2.8  27.0   280    6    3   6.0   3.3    3.5  38.3    -6.3    129  0.7
  7000   -2.4  27.7   275    7    4   6.2   3.4    3.2  37.8    -6.6    109  0.6
  6750   -2.0  28.4   265    8    4   5.5   3.0    2.9  37.2    -6.9     89  0.5
  6500   -1.5  29.3   255    9    5   8.0   4.4    2.6  36.7    -7.2     68  0.3
  6250   -1.1  30.0   245   10    5  -1.1  -0.6    2.4  36.2    -7.5     48  0.2
  6000   -1.5  29.3   240   12    6  -2.0  -1.1    1.2  34.2    -8.6     52  0.3
  5750   -1.9  28.6   225    8    4 -24.3 -13.3    0.0  32.1    -9.8     56  0.3
  5500   -5.8  21.6   195    6    3 -75.4 -41.4   -4.6  23.6   -14.4    166  0.8

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

           12/24/2014 at 0800 MST          |       12/24/2014 at 1100 MST
                                           |
K index... +0.6  LI... +6.6                | K index... 0.0  LI... +7.5
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 -56.5 -69.7  320  32 17   1.9   1.1 | -57.7 -71.9  300  34 18   2.8   1.5
 45000 -53.4 -64.1  325  61 31   0.8   0.5 | -53.3 -63.9  315  58 30   1.4   0.8
 40000 -55.4 -67.7  340  62 32  -1.4  -0.8 | -56.1 -69.0  330  52 27  -1.9  -1.1
 38000 -55.7 -68.3  345  65 34   1.0   0.6 | -56.5 -69.7  335  54 28   1.4   0.8
 36000 -55.1 -67.2  345  73 37   1.0   0.6 | -55.7 -68.3  330  60 31   1.4   0.7
 34000 -54.4 -65.9  345  80 41   5.1   2.8 | -54.7 -66.5  325  66 34   5.7   3.1
 32000 -49.7 -57.5  345  75 38   7.8   4.3 | -50.1 -58.2  330  61 31   7.7   4.2
 30000 -44.5 -48.1  345  69 36   7.6   4.2 | -44.8 -48.6  335  56 29   8.6   4.7
 29000 -42.2 -44.0  345  68 35   7.6   4.2 | -42.2 -44.0  335  52 27   8.6   4.7
 28000 -39.9 -39.8  345  67 35   7.6   4.2 | -39.6 -39.3  340  49 25   8.6   4.7
 27000 -37.6 -35.7  350  66 34   7.6   4.2 | -37.1 -34.8  340  46 24   8.5   4.7
 26000 -35.4 -31.7  350  62 32   7.5   4.1 | -34.6 -30.3  340  43 22   8.2   4.5
 25000 -33.1 -27.6  350  58 30   7.5   4.1 | -32.1 -25.8  340  41 21   8.2   4.5
 24000 -30.9 -23.6  350  53 27   7.4   4.1 | -29.7 -21.5  340  39 20   8.3   4.5
 23000 -28.5 -19.3  350  50 26   8.0   4.4 | -27.4 -17.3  335  37 19   7.6   4.2
 22000 -26.2 -15.2  350  47 24   8.0   4.4 | -25.1 -13.2  335  36 19   7.6   4.2
 21000 -23.8 -10.8  355  44 23   7.9   4.3 | -22.8  -9.0  335  35 18   7.6   4.2
 20000 -21.5  -6.7  350  43 22   7.6   4.2 | -20.5  -4.9  330  35 18   7.7   4.2
 19500 -20.4  -4.7  350  43 22   7.6   4.2 | -19.4  -2.9  330  36 18   7.7   4.2
 19000 -19.2  -2.6  350  42 22   7.6   4.2 | -18.3  -0.9  330  36 18   7.7   4.2
 18500 -18.1  -0.6  350  42 21   7.7   4.2 | -17.1   1.2  330  36 19   7.7   4.2
 18000 -17.1   1.2  345  41 21   5.7   3.1 | -16.1   3.0  330  36 19   6.7   3.7
 17500 -16.2   2.8  345  41 21   5.8   3.2 | -15.1   4.8  330  36 19   6.8   3.7
 17000 -15.4   4.3  345  41 21   5.8   3.2 | -14.1   6.6  330  37 19   6.5   3.6
 16500 -14.5   5.9  340  41 21   5.7   3.1 | -13.1   8.4  330  36 19   6.4   3.5
 16000 -13.7   7.3  340  41 21   5.8   3.2 | -12.2  10.0  330  35 18   6.3   3.5
 15500 -12.8   9.0  340  40 21   6.2   3.4 | -11.3  11.7  330  34 18   6.0   3.3
 15000 -11.4  11.5  340  39 20   6.0   3.3 |  -9.9  14.2  330  31 16   5.6   3.1
 14500 -10.6  12.9  340  37 19   5.8   3.2 |  -9.1  15.6  325  29 15   5.2   2.9
 14000  -9.7  14.5  340  36 19   5.7   3.1 |  -8.4  16.9  320  27 14   5.0   2.8
 13500  -8.9  16.0  345  35 18   5.3   2.9 |  -7.7  18.1  320  25 13   4.5   2.5
 13000  -8.2  17.2  345  34 17   5.2   2.9 |  -7.0  19.4  315  23 12   4.5   2.5
 12500  -7.5  18.5  345  33 17   4.7   2.6 |  -6.4  20.5  315  20 10   4.0   2.2
 12000  -6.8  19.8  345  32 16   4.8   2.6 |  -5.8  21.6  315  18  9   4.1   2.2
 11500  -6.0  21.2  350  30 16   5.7   3.1 |  -5.1  22.8  320  16  8   5.7   3.1
 11000  -5.1  22.8  350  29 15   5.7   3.2 |  -4.3  24.3  325  14  7   5.6   3.1
 10500  -4.2  24.4  350  28 14   6.4   3.5 |  -3.5  25.7  325  12  6   5.3   2.9
 10250  -3.7  25.3  355  28 14   6.3   3.4 |  -3.1  26.4  325  11  6   5.2   2.9
 10000  -3.2  26.2  355  28 14   6.5   3.6 |  -2.7  27.1  325  10  5   5.9   3.3
  9750  -2.8  27.0  355  26 13   4.1   2.3 |  -2.2  28.0  320   9  5   6.3   3.5
  9500  -2.6  27.3  350  24 12   2.1   1.2 |  -1.7  28.9  315   8  4   6.0   3.3
  9250  -2.4  27.7  350  22 11   2.8   1.5 |  -1.3  29.7  310   7  4   6.1   3.3
  9000  -2.2  28.0  345  20 10   2.2   1.2 |  -0.8  30.6  300   7  3   6.2   3.4
  8750  -2.0  28.4  340  16  8   2.2   1.2 |  -0.3  31.5  295   7  4   6.6   3.6
  8500  -1.8  28.8  335  14  7   2.7   1.5 |   0.2  32.4  290   8  4   6.8   3.7
  8250  -1.6  29.1  325  12  6   2.7   1.5 |   0.7  33.3  285   8  4   6.5   3.6
  8000  -1.4  29.5  320  10  5   5.4   3.0 |   1.2  34.2  285   9  4   8.1   4.5
  7750  -0.9  30.4  320  10  5   7.2   4.0 |   1.8  35.2  290  10  5   7.6   4.2
  7500  -0.3  31.5  320  10  5   8.5   4.7 |   2.3  36.1  295  12  6   6.8   3.7
  7250   0.3  32.5  325  11  6   3.7   2.0 |   2.8  37.0  300  13  7   4.2   2.3
  7000   0.2  32.4  315  14  7  -1.6  -0.9 |   2.8  37.0  300  15  8  -2.0  -1.1
  6750   0.0  32.0  310  17  9  -5.7  -3.1 |   2.5  36.5  295  17  9  -4.9  -2.7
  6500  -0.6  30.9  300  19 10 -10.3  -5.6 |   2.1  35.8  285  16  8  -5.4  -3.0
  6250  -1.4  29.5  290  19 10 -11.6  -6.3 |   1.7  35.1  280  15  8  -6.2  -3.4
  6000  -2.4  27.7  280  15  8 -13.5  -7.4 |   1.2  34.2  270  11  6  -7.2  -3.9
  5750  -3.4  25.9  265  12  6 -11.2  -6.1 |   0.7  33.3  250   8  4  -5.8  -3.2
  5500  -4.3  24.3  245  10  5 -16.3  -8.9 |   0.4  32.7  210   6  3   1.9   1.0

           12/24/2014 at 1400 MST          |       12/24/2014 at 1700 MST
                                           |
K index... +5.0  LI... +5.8                | K index... -19.0  LI... +5.2
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -1.0
                                           |
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  280  43 22   3.1   1.7 | -58.0 -72.4  280  45 23   3.7   2.0
 45000 -53.6 -64.5  300  56 29   3.5   1.9 | -52.5 -62.5  290  55 28   4.3   2.3
 40000 -55.8 -68.4  315  62 32  -1.7  -1.0 | -57.1 -70.8  300  65 33  -3.3  -1.8
 38000 -56.2 -69.2  315  64 33   1.4   0.8 | -57.6 -71.7  300  68 35   3.2   1.8
 36000 -55.3 -67.5  320  66 34   1.4   0.8 | -55.7 -68.3  300  71 37   3.2   1.7
 34000 -54.4 -65.9  320  67 34   5.3   2.9 | -53.8 -64.8  300  74 38   6.5   3.5
 32000 -49.8 -57.6  315  57 29   7.7   4.2 | -48.8 -55.8  295  59 31   8.3   4.6
 30000 -45.2 -49.4  310  47 24   8.6   4.7 | -43.8 -46.8  285  46 24   7.3   4.0
 29000 -41.9 -43.4  310  43 22   8.7   4.8 | -41.9 -43.4  285  45 23   6.4   3.5
 28000 -39.3 -38.7  305  40 20   8.7   4.8 | -40.0 -40.0  290  45 23   6.4   3.5
 27000 -36.7 -34.1  305  36 19   8.7   4.8 | -37.6 -35.7  290  45 23   6.4   3.5
 26000 -34.3 -29.7  305  35 18   7.9   4.3 | -35.4 -31.7  290  43 22   7.6   4.2
 25000 -31.9 -25.4  305  35 18   7.9   4.3 | -33.2 -27.8  295  40 21   7.6   4.2
 24000 -29.6 -21.3  305  35 18   8.0   4.4 | -30.9 -23.6  295  38 19   7.6   4.2
 23000 -27.4 -17.3  305  35 18   6.7   3.7 | -28.5 -19.3  295  35 18   8.0   4.4
 22000 -25.4 -13.7  305  36 18   6.7   3.7 | -26.1 -15.0  295  33 17   8.0   4.4
 21000 -23.4 -10.1  305  36 19   6.9   3.8 | -23.7 -10.7  295  30 15   8.0   4.4
 20000 -21.1  -6.0  305  34 18   8.0   4.4 | -21.3  -6.3  295  29 15   7.9   4.3
 19500 -19.9  -3.8  305  33 17   8.0   4.4 | -20.2  -4.4  295  29 15   7.9   4.3
 19000 -18.7  -1.7  305  32 17   8.0   4.4 | -19.0  -2.2  295  28 15   7.9   4.3
 18500 -17.5   0.5  305  31 16   8.2   4.5 | -17.8  -0.0  295  28 14   7.9   4.3
 18000 -16.4   2.5  305  30 15   6.2   3.4 | -16.7   1.9  295  27 14   7.3   4.0
 17500 -15.4   4.3  310  29 15   6.5   3.5 | -15.6   3.9  295  27 14   7.3   4.0
 17000 -14.5   5.9  310  28 14   6.7   3.7 | -14.4   6.1  295  26 13   7.0   3.8
 16500 -13.5   7.7  310  27 14   6.8   3.7 | -13.5   7.7  295  25 13   6.7   3.7
 16000 -12.5   9.5  315  27 14   6.8   3.7 | -12.5   9.5  295  23 12   6.6   3.6
 15500 -11.5  11.3  315  26 13   6.3   3.5 | -11.5  11.3  295  22 11   6.2   3.4
 15000 -10.6  12.9  315  26 13   6.4   3.5 | -10.6  12.9  295  20 10   6.2   3.4
 14500  -9.3  15.3  315  25 13   6.0   3.3 |  -9.6  14.7  295  19 10   7.2   3.9
 14000  -8.4  16.9  320  24 12   6.0   3.3 |  -8.0  17.6  295  16  8   7.3   4.0
 13500  -7.5  18.5  320  22 11   5.7   3.1 |  -6.8  19.8  300  15  8   8.2   4.5
 13000  -6.7  19.9  320  21 11   5.8   3.2 |  -5.6  21.9  300  15  8   8.1   4.4
 12500  -5.9  21.4  320  19 10   4.9   2.7 |  -4.4  24.1  300  15  7   8.1   4.4
 12000  -5.2  22.6  320  17  9   4.9   2.7 |  -3.2  26.2  305  15  7   8.1   4.5
 11500  -4.4  24.1  320  15  7   5.4   3.0 |  -2.0  28.4  305  15  8   8.0   4.4
 11000  -3.6  25.5  315  12  6   5.3   2.9 |  -0.8  30.6  305  17  9   8.3   4.5
 10500  -2.7  27.1  310  11  6   7.1   3.9 |   0.2  32.4  305  19 10   5.1   2.8
 10250  -2.2  28.0  310  11  5   7.0   3.8 |   0.6  33.1  305  20 10   5.3   2.9
 10000  -1.6  29.1  310  10  5   8.6   4.7 |   1.0  33.8  305  20 10   6.1   3.3
  9750  -0.9  30.4  305  11  5   9.8   5.4 |   1.4  34.5  305  21 11   4.5   2.5
  9500  -0.2  31.6  305  12  6   9.6   5.2 |   1.6  34.9  300  22 11   2.7   1.5
  9250   0.5  32.9  305  13  7   9.9   5.5 |   1.8  35.2  295  23 12   3.2   1.8
  9000   1.3  34.3  305  14  7   8.6   4.7 |   2.0  35.6  295  24 12   3.1   1.7
  8750   1.8  35.2  305  15  8   5.0   2.7 |   2.2  36.0  290  24 12   2.7   1.5
  8500   2.0  35.6  300  17  9   3.3   1.8 |   2.3  36.1  290  23 12   2.5   1.4
  8250   2.3  36.1  300  20 10   4.5   2.4 |   2.5  36.5  285  22 11   2.3   1.2
  8000   2.6  36.7  300  22 11   1.6   0.9 |   2.6  36.7  280  21 11   3.5   1.9
  7750   2.5  36.5  290  22 11   0.0   0.0 |   2.9  37.2  275  19 10   4.6   2.5
  7500   2.6  36.7  285  21 11   1.4   0.8 |   3.2  37.8  270  17  9   4.3   2.4
  7250   2.7  36.9  280  20 10   1.3   0.7 |   3.5  38.3  265  14  7   4.1   2.2
  7000   2.8  37.0  275  18  9   3.6   2.0 |   3.8  38.8  255  12  6   5.6   3.1
  6750   3.2  37.8  270  15  8   4.3   2.4 |   4.3  39.7  250  11  5   7.2   3.9
  6500   3.4  38.1  260  12  6   2.9   1.6 |   4.8  40.6  240   9  5   7.5   4.1
  6250   3.7  38.7  250  10  5   4.9   2.7 |   5.4  41.7  230   8  4   5.3   2.9
  6000   4.2  39.6  240   8  4   7.0   3.8 |   5.5  41.9  220   7  3  -1.4  -0.8
  5750   4.7  40.5  225   6  3   7.3   4.0 |   5.4  41.7  210   6  3   3.0   1.7
  5500   5.3  41.5  215   5  2   9.6   5.3 |   5.6  42.1  195   6  3  -2.9  -1.6
________________________________________________________________________________

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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