328 UXUS97 KBOU 060033 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 1833 MDT Thursday, June 5, 2014 This forecast is for Friday, June 6, 2014: If the trigger temperature of 72.3 F/22.4 C is reached...then Thermal Soaring Index....................... Fair Maximum rate of lift........................ 302 ft/min (1.5 m/s) Maximum height of thermals.................. 13859 ft MSL (8572 ft AGL) Forecast maximum temperature................... 80.0 F/27.1 C Time of trigger temperature.................... 1030 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................. 10227 ft MSL (4939 ft AGL) Thermal soaring outlook for Saturday 06/07..... Fair Wave Soaring Index............................. Poor Wave Soaring Index trend (to 1800 MDT)......... No change Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1800 MDT)................ Neither Potential height of wave....................... 16863 ft MSL (11576 ft AGL) Wave soaring outlook for Saturday 06/07........ Poor Remarks... None Sunrise/Sunset.................... 05:31:58 / 20:24:15 MDT Total possible sunshine........... 14 hr 52 min 17 sec (892 min 17 sec) Altitude of sun at 12:58:17 MDT... 72.91 degrees Upper air data from numerical model forecast valid on 06/06/2014 at 0600 MDT Freezing level.................. 14297 ft MSL (9010 ft AGL) Convective condensation level... 12641 ft MSL (7354 ft AGL) Lifted condensation level....... 12914 ft MSL (7627 ft AGL) Lifted index.................... -7.4 K index......................... +24.8 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 -59.1 -74.4 270 43 22 0.9 0.5 M M M M M 45000 -57.9 -72.2 270 48 24 -0.3 -0.2 M M M M M 40000 -58.3 -72.9 260 43 22 -1.0 -0.5 M M M M M 38000 -55.7 -68.3 260 41 21 5.0 2.8 M M M M M 36000 -52.7 -62.9 255 39 20 5.0 2.8 M M M M M 34000 -48.7 -55.7 255 39 20 8.2 4.5 M M M M M 32000 -43.1 -45.6 250 41 21 8.2 4.5 M M M M M 30000 -38.2 -36.8 250 41 21 8.1 4.5 36.7 98.0 7.6 M M 29000 -35.8 -32.4 250 40 21 8.1 4.5 36.0 96.9 7.2 M M 28000 -33.3 -27.9 250 39 20 8.1 4.4 35.5 95.9 6.9 M M 27000 -30.9 -23.6 250 37 19 8.2 4.5 34.9 94.8 6.4 M M 26000 -28.4 -19.1 250 35 18 8.2 4.5 34.2 93.6 6.0 M M 25000 -26.0 -14.8 255 33 17 8.2 4.5 33.7 92.7 5.7 M M 24000 -23.6 -10.5 255 31 16 7.7 4.2 33.0 91.5 5.2 M M 23000 -21.3 -6.3 250 30 15 7.6 4.2 32.2 90.0 4.5 M M 22000 -19.1 -2.4 250 29 15 7.6 4.2 31.5 88.7 4.0 M M 21000 -16.8 1.8 255 27 14 7.7 4.2 30.8 87.4 3.4 M M 20000 -14.5 5.9 255 24 13 7.8 4.3 30.0 86.1 2.8 M M 19500 -13.3 8.1 260 23 12 7.9 4.3 29.7 85.5 2.5 M M 19000 -12.2 10.0 260 22 11 8.3 4.6 29.4 85.0 2.2 M M 18500 -10.9 12.4 265 20 11 8.9 4.9 29.3 84.7 2.0 M M 18000 -9.6 14.7 265 19 10 9.0 4.9 29.1 84.5 1.9 M M 17500 -8.3 17.1 270 17 9 9.0 4.9 29.0 84.2 1.8 M M 17000 -7.0 19.4 275 16 8 9.0 4.9 28.9 84.0 1.6 M M 16500 -5.6 21.9 280 15 8 8.7 4.8 28.8 83.8 1.5 M M 16000 -3.8 25.2 285 13 7 8.5 4.7 28.4 83.2 1.2 M M 15500 -2.5 27.5 290 12 6 8.0 4.4 28.2 82.8 1.0 M M 15000 -1.4 29.5 295 10 5 7.8 4.3 27.9 82.2 0.6 M M 14500 -0.2 31.6 300 8 4 7.9 4.3 27.6 81.6 0.3 M M 14000 0.9 33.6 305 6 3 8.0 4.4 27.2 81.0 0.0 M M 13500 2.1 35.8 320 5 3 8.2 4.5 27.0 80.5 -0.3 657 3.3 13000 3.4 38.1 320 4 2 9.0 4.9 26.8 80.2 -0.4 603 3.1 12500 4.7 40.5 315 4 2 9.0 4.9 26.7 80.0 -0.6 549 2.8 12000 5.9 42.6 280 5 2 7.5 4.1 26.4 79.5 -0.9 499 2.5 11500 7.0 44.6 260 8 4 7.8 4.3 26.1 78.9 -1.3 452 2.3 11000 7.9 46.2 240 11 5 5.8 3.2 25.6 78.1 -1.8 410 2.1 10500 8.6 47.5 230 14 7 5.3 2.9 25.0 77.0 -2.6 373 1.9 10250 8.9 48.0 225 16 8 4.2 2.3 24.6 76.3 -3.0 357 1.8 10000 9.2 48.6 220 17 9 6.4 3.5 24.2 75.6 -3.4 340 1.7 9750 9.7 49.5 210 20 10 7.8 4.3 24.0 75.3 -3.7 317 1.6 9500 10.2 50.4 205 22 11 7.5 4.1 23.9 75.0 -3.9 295 1.5 9250 10.7 51.3 200 25 13 5.6 3.1 23.7 74.6 -4.2 274 1.4 9000 11.0 51.8 195 27 14 5.7 3.1 23.3 73.9 -4.6 256 1.3 8750 11.5 52.7 195 29 15 7.2 3.9 23.1 73.5 -4.8 234 1.2 8500 12.0 53.6 190 31 16 6.9 3.8 22.8 73.1 -5.1 212 1.1 8250 12.5 54.5 190 33 17 7.3 4.0 22.6 72.7 -5.3 190 1.0 8000 13.0 55.4 190 34 18 7.4 4.1 22.5 72.4 -5.5 166 0.8 7750 13.6 56.5 190 35 18 7.4 4.1 22.3 72.1 -5.7 143 0.7 7500 14.1 57.4 190 35 18 7.6 4.2 22.1 71.8 -5.9 119 0.6 7250 14.7 58.5 190 35 18 8.0 4.4 22.0 71.5 -6.1 95 0.5 7000 15.2 59.4 190 35 18 8.0 4.4 21.8 71.3 -6.3 71 0.4 6750 15.8 60.4 190 34 18 7.9 4.3 21.7 71.0 -6.5 47 0.2 6500 16.2 61.2 190 33 17 3.5 1.9 21.4 70.6 -6.8 25 0.1 6250 16.3 61.3 190 29 15 0.0 0.0 20.8 69.4 -7.5 17 0.1 6000 16.3 61.3 190 25 13 1.3 0.7 20.1 68.1 -8.2 8 0.0 5750 16.3 61.3 195 22 11 -3.1 -1.7 19.3 66.8 -9.0 2 0.0 5500 15.7 60.3 195 16 8 -10.9 -6.0 18.1 64.6 -10.3 12 0.1 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/06/2014 at 0900 MDT | 06/06/2014 at 1200 MDT | K index... +18.6 LI... -6.1 | K index... +20.3 LI... -6.2 CAPE... +1887.6 CIN... -60.5 | CAPE... +1729.5 CIN... -13.8 | 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 -58.7 -73.7 265 40 21 1.2 0.6 | -59.6 -75.3 265 42 22 0.8 0.4 45000 -57.2 -71.0 270 45 23 0.0 0.0 | -58.4 -73.1 260 43 22 0.8 0.4 40000 -57.1 -70.8 270 39 20 -0.5 -0.2 | -57.2 -71.0 255 40 21 0.6 0.3 38000 -54.8 -66.6 265 38 20 4.5 2.4 | -54.2 -65.6 255 41 21 5.6 3.1 36000 -52.2 -62.0 265 38 19 4.5 2.4 | -50.8 -59.4 260 41 21 5.6 3.1 34000 -48.5 -55.3 260 39 20 7.6 4.2 | -47.1 -52.8 260 42 22 6.8 3.8 32000 -43.4 -46.1 260 41 21 7.6 4.2 | -42.4 -44.3 255 43 22 6.8 3.7 30000 -38.6 -37.5 260 40 21 8.1 4.4 | -37.8 -36.0 260 41 21 8.2 4.5 29000 -36.2 -33.2 260 40 20 8.1 4.4 | -35.4 -31.7 260 40 21 8.2 4.5 28000 -33.8 -28.8 260 39 20 8.1 4.4 | -32.9 -27.2 260 38 20 8.3 4.6 27000 -31.5 -24.7 260 36 19 7.4 4.1 | -30.7 -23.3 260 36 18 7.3 4.0 26000 -29.3 -20.7 260 34 17 7.4 4.1 | -28.5 -19.3 265 32 17 7.3 4.0 25000 -27.1 -16.8 260 31 16 7.5 4.1 | -26.3 -15.3 265 29 15 7.3 4.0 24000 -24.8 -12.6 260 29 15 8.0 4.4 | -24.1 -11.4 265 27 14 7.4 4.1 23000 -22.4 -8.3 260 29 15 8.1 4.4 | -21.9 -7.4 265 25 13 7.4 4.1 22000 -20.0 -4.0 260 30 15 8.1 4.4 | -19.7 -3.5 265 23 12 7.4 4.1 21000 -17.5 0.5 265 28 15 8.5 4.7 | -17.3 0.9 265 22 11 8.4 4.6 20000 -14.9 5.2 270 27 14 8.5 4.7 | -14.8 5.4 270 21 11 8.4 4.6 19500 -13.7 7.3 270 26 13 8.5 4.7 | -13.6 7.5 270 21 11 8.4 4.6 19000 -12.4 9.7 275 25 13 8.4 4.6 | -12.4 9.7 270 20 10 8.3 4.6 18500 -11.2 11.8 275 23 12 8.2 4.5 | -11.1 12.0 275 19 10 8.2 4.5 18000 -9.9 14.2 275 21 11 8.1 4.4 | -9.9 14.2 275 19 10 8.2 4.5 17500 -8.7 16.3 280 20 10 9.3 5.1 | -8.7 16.3 280 18 9 8.6 4.7 17000 -7.3 18.9 280 18 9 9.3 5.1 | -7.4 18.7 290 17 9 8.6 4.7 16500 -5.9 21.4 280 16 8 9.3 5.1 | -6.1 21.0 295 17 9 8.8 4.9 16000 -3.9 25.0 275 14 7 9.3 5.1 | -4.1 24.6 300 15 8 9.1 5.0 15500 -2.5 27.5 275 12 6 9.4 5.1 | -2.7 27.1 300 14 7 9.0 5.0 15000 -1.1 30.0 275 11 5 9.4 5.2 | -1.4 29.5 300 12 6 9.0 4.9 14500 0.3 32.5 275 9 5 9.0 4.9 | -0.0 32.0 305 11 6 9.1 5.0 14000 1.5 34.7 270 7 4 8.3 4.6 | 1.3 34.3 305 10 5 9.2 5.0 13500 2.7 36.9 260 5 3 8.3 4.6 | 2.7 36.9 305 8 4 9.1 5.0 13000 3.9 39.0 240 3 2 8.3 4.6 | 4.0 39.2 305 7 4 8.5 4.7 12500 5.2 41.4 200 2 1 8.3 4.6 | 5.2 41.4 295 5 3 8.6 4.7 12000 6.4 43.5 175 2 1 8.5 4.7 | 6.5 43.7 290 4 2 8.6 4.7 11500 7.7 45.9 155 1 1 8.4 4.6 | 7.7 45.9 285 3 2 8.7 4.8 11000 8.9 48.0 170 1 1 8.7 4.8 | 8.9 48.0 280 3 2 7.2 4.0 10500 10.2 50.4 215 1 1 6.8 3.7 | 9.9 49.8 280 3 2 9.8 5.4 10250 10.6 51.1 220 1 1 5.4 2.9 | 10.7 51.3 270 4 2 9.7 5.3 10000 11.1 52.0 220 3 2 7.9 4.3 | 11.1 52.0 240 4 2 6.5 3.5 9750 11.6 52.9 220 5 2 8.1 4.5 | 11.5 52.7 220 6 3 7.6 4.2 9500 12.2 54.0 220 6 3 8.2 4.5 | 12.0 53.6 210 7 4 7.5 4.1 9250 12.7 54.9 220 8 4 5.4 2.9 | 12.4 54.3 205 9 5 7.2 3.9 9000 12.9 55.2 220 11 6 4.8 2.7 | 12.9 55.2 200 9 5 8.4 4.6 8750 13.4 56.1 215 14 7 6.8 3.7 | 13.5 56.3 200 10 5 9.6 5.3 8500 13.8 56.8 215 17 9 6.1 3.3 | 14.2 57.6 195 10 5 9.5 5.2 8250 14.1 57.4 215 20 10 4.9 2.7 | 14.9 58.8 195 11 6 10.4 5.7 8000 14.4 57.9 210 23 12 4.5 2.5 | 15.6 60.1 195 11 6 10.3 5.6 7750 14.6 58.3 205 24 12 4.8 2.7 | 16.4 61.5 195 11 6 9.5 5.2 7500 14.9 58.8 205 25 13 5.6 3.1 | 17.1 62.8 195 11 6 10.0 5.5 7250 15.3 59.5 200 24 12 6.8 3.7 | 17.8 64.0 195 11 6 10.8 5.9 7000 15.7 60.3 200 23 12 7.4 4.0 | 18.7 65.7 195 11 6 10.7 5.9 6750 16.2 61.2 195 21 11 8.4 4.6 | 19.4 66.9 195 11 6 9.7 5.3 6500 16.8 62.2 195 20 10 10.1 5.5 | 20.1 68.2 195 11 6 10.3 5.6 6250 17.6 63.7 195 19 10 11.1 6.1 | 20.9 69.6 190 11 6 11.5 6.3 6000 18.4 65.1 195 18 9 10.2 5.6 | 21.8 71.2 190 11 5 10.2 5.6 5750 19.2 66.6 190 17 9 12.3 6.7 | 22.6 72.7 190 10 5 13.1 7.2 5500 20.3 68.5 190 16 8 18.8 10.3 | 23.9 75.0 190 10 5 24.1 13.2 06/06/2014 at 1500 MDT | 06/06/2014 at 1800 MDT | K index... +23.6 LI... -2.5 | K index... +27.1 LI... -3.0 CAPE... +527.2 CIN... -32.8 | CAPE... +674.5 CIN... -32.5 | 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 -59.9 -75.8 270 44 23 1.0 0.6 | -59.4 -74.9 270 43 22 0.6 0.3 45000 -58.4 -73.1 265 45 23 0.7 0.4 | -58.6 -73.5 260 47 24 0.3 0.1 40000 -57.3 -71.1 260 48 25 1.0 0.5 | -58.2 -72.8 260 52 27 0.5 0.2 38000 -54.3 -65.7 260 46 24 5.4 3.0 | -54.6 -66.3 260 51 26 6.5 3.6 36000 -51.1 -60.0 255 44 23 5.4 3.0 | -50.7 -59.3 260 50 26 6.5 3.6 34000 -47.0 -52.6 255 43 22 7.9 4.3 | -46.0 -50.8 260 47 24 7.2 4.0 32000 -41.7 -43.1 255 42 22 7.9 4.3 | -41.6 -42.9 255 44 23 7.2 4.0 30000 -36.9 -34.4 255 39 20 8.0 4.4 | -37.0 -34.6 260 42 21 8.0 4.4 29000 -34.5 -30.1 255 37 19 8.0 4.4 | -34.6 -30.3 260 41 21 8.0 4.4 28000 -32.1 -25.8 255 35 18 8.0 4.4 | -32.2 -26.0 260 40 21 8.0 4.4 27000 -29.8 -21.6 260 33 17 8.0 4.4 | -29.8 -21.6 265 39 20 8.1 4.5 26000 -27.4 -17.3 260 32 17 8.0 4.4 | -27.3 -17.1 265 37 19 8.1 4.5 25000 -25.0 -13.0 260 31 16 8.0 4.4 | -24.9 -12.8 270 35 18 8.1 4.5 24000 -22.7 -8.9 265 31 16 7.4 4.1 | -22.5 -8.5 270 34 17 7.6 4.2 23000 -20.5 -4.9 265 31 16 7.4 4.1 | -20.2 -4.4 275 33 17 7.6 4.2 22000 -18.3 -0.9 270 31 16 7.4 4.1 | -17.9 -0.2 280 32 16 7.6 4.2 21000 -16.1 3.0 275 30 15 7.5 4.1 | -15.8 3.6 280 32 17 7.1 3.9 20000 -13.9 7.0 275 29 15 7.5 4.1 | -13.7 7.3 285 34 17 7.2 3.9 19500 -12.8 9.0 275 28 14 7.5 4.1 | -12.7 9.1 285 35 18 7.3 4.0 19000 -11.7 10.9 275 27 14 7.5 4.1 | -11.6 11.1 285 36 18 7.5 4.1 18500 -10.6 12.9 280 26 13 7.5 4.1 | -10.5 13.1 290 34 18 7.9 4.4 18000 -9.5 14.9 280 24 12 7.5 4.1 | -9.3 15.3 290 33 17 8.0 4.4 17500 -8.3 17.1 280 23 12 8.3 4.5 | -8.2 17.2 290 31 16 8.3 4.6 17000 -7.1 19.2 280 21 11 8.3 4.5 | -6.3 20.7 295 29 15 8.4 4.6 16500 -5.9 21.4 280 20 10 8.5 4.7 | -5.1 22.8 300 27 14 8.6 4.7 16000 -4.0 24.8 280 18 9 8.7 4.8 | -3.8 25.2 300 25 13 8.6 4.7 15500 -2.7 27.1 280 17 9 8.7 4.8 | -2.6 27.3 300 24 12 8.7 4.8 15000 -1.4 29.5 280 15 8 8.6 4.7 | -1.3 29.7 300 22 11 8.7 4.8 14500 -0.1 31.8 280 14 7 8.6 4.7 | -0.0 32.0 305 20 10 8.4 4.6 14000 1.2 34.2 280 13 7 8.6 4.7 | 1.1 34.0 305 17 9 7.7 4.2 13500 2.5 36.5 280 11 6 8.6 4.7 | 2.3 36.1 305 15 8 7.7 4.2 13000 3.7 38.7 275 10 5 8.2 4.5 | 3.4 38.1 305 12 6 7.8 4.3 12500 4.9 40.8 275 9 5 8.2 4.5 | 4.6 40.3 305 10 5 7.7 4.2 12000 6.1 43.0 270 8 4 8.2 4.5 | 5.8 42.4 300 7 4 9.0 4.9 11500 7.3 45.1 265 7 4 8.4 4.6 | 7.1 44.8 290 5 3 9.1 5.0 11000 8.4 47.1 265 7 4 7.0 3.8 | 8.2 46.8 265 4 2 6.9 3.8 10500 9.4 48.9 260 7 3 9.8 5.4 | 9.2 48.6 225 3 2 8.5 4.7 10250 10.2 50.4 260 6 3 11.1 6.1 | 9.9 49.8 200 4 2 9.5 5.2 10000 10.8 51.4 260 6 3 8.2 4.5 | 10.5 50.9 190 5 2 8.1 4.5 9750 11.5 52.7 255 6 3 8.8 4.8 | 11.1 52.0 185 6 3 8.3 4.6 9500 12.1 53.8 255 6 3 8.7 4.8 | 11.7 53.1 180 7 3 8.3 4.6 9250 12.7 54.9 250 6 3 7.7 4.2 | 12.3 54.1 180 8 4 7.5 4.1 9000 13.3 55.9 250 6 3 8.7 4.8 | 12.9 55.2 180 8 4 8.7 4.8 8750 14.0 57.2 250 6 3 10.2 5.6 | 13.6 56.5 180 9 4 10.3 5.7 8500 14.7 58.5 250 6 3 9.8 5.4 | 14.3 57.7 180 9 5 9.9 5.4 8250 15.4 59.7 250 6 3 10.0 5.5 | 15.0 59.0 175 10 5 10.2 5.6 8000 16.1 61.0 245 6 3 9.7 5.3 | 15.8 60.4 175 10 5 9.7 5.3 7750 16.8 62.2 245 6 3 9.2 5.1 | 16.4 61.5 175 10 5 9.1 5.0 7500 17.5 63.5 245 6 3 9.6 5.2 | 17.1 62.8 175 10 5 9.6 5.2 7250 18.2 64.8 245 6 3 10.2 5.6 | 17.9 64.2 175 10 5 10.4 5.7 7000 19.0 66.2 245 6 3 10.2 5.6 | 18.6 65.5 175 11 5 10.4 5.7 6750 19.7 67.5 245 6 3 9.0 4.9 | 19.4 66.9 175 11 5 9.0 5.0 6500 20.4 68.7 245 6 3 9.9 5.4 | 20.1 68.2 175 11 6 9.6 5.3 6250 21.2 70.2 245 6 3 11.4 6.2 | 20.9 69.6 175 11 5 10.9 6.0 6000 22.0 71.6 245 6 3 10.5 5.8 | 21.7 71.1 175 10 5 10.3 5.7 5750 22.7 72.9 245 6 3 10.2 5.6 | 22.4 72.3 175 10 5 11.5 6.3 5500 23.6 74.5 245 6 3 13.4 7.3 | 23.4 74.1 175 10 5 15.2 8.4 ________________________________________________________________________________ This product is issued twice per day, once by approximately 0630 MST/0730 MDT (1330 UTC) and again by approximately 1830 MST/1930 MDT (0130 UTC). It is not continuously monitored nor updated after its initial issuance. The information contained herein is based on rawinsonde observation and/or numerical weather prediction model data taken near the old Stapleton Airport site in Denver, Colorado at North Latitude: 39 deg 46 min 5.016 sec West Longitude: 104 deg 52 min 9.984 sec Elevation: 5285 feet (1611 meters) and may not be representative of other areas along the Front Range of the Colorado Rocky Mountains. Note that some elevations in numerical weather prediction models differ from actual station elevations, which can lead to data which appear to be below ground. Erroneous data such as these should not be used. The content and format of this report as well as the issuance times are subject to change without prior notice. Comments and suggestions are welcome and should be directed to one of the addresses or phone numbers shown at the bottom of this page. To expedite a response to comments, be sure to mention your interest in the soaring forecast. DEFINITIONS: CAPE (Convective Available Potential Energy) - An integrated measure of the energy available for convective development, also known as the positive area on a thermodynamic diagram. Units are Joules per kilogram. Larger values are indicative of greater instability and the possibility of stronger convective activity, including thunderstorms. Values around or greater than 1000 suggest the possibility of severe weather should convective activity develop. CIN (Convective Inhibition) - An integrated measure of the amount of energy needed to initiate convective activity, also known as the negative area on a thermodynamic diagram. Units are Joules per kilogram. The more negative this number, the more energy is required to initiate convection. This inhibitive energy can be overcome through surface heating, cooling aloft, lifting mechanisms (orographic, frontal, gravity waves, etc.) Convective Condensation Level - The height to which an air parcel possessing the average saturation mixing ratio in the lowest 4000 feet of the airmass, if heated sufficiently from below, will rise dry adiabatically until it just becomes saturated. It estimates the base of cumulus clouds that are produced by surface heating only. Convection Temperature (ConvectionT) - The surface temperature required to make the airmass dry adiabatic up to the given level. It can be considered a "trigger temperature" for that level. Freezing Level - The height where the temperature is zero degrees Celsius. Height of Stable Layer - The height (between 12,000 and 18,000 feet above mean sea level) where the smallest lapse rate exists. The location and existence of this feature is important in the generation of mountain waves. K Index - A measure of stability which combines the temperature difference between approximately 5,000 and 18,000 feet above the surface, the amount of moisture at approximately 5,000 feet above the surface, and a measure of the dryness at approximately 10,000 feet above the surface. Larger positive numbers indicate more instability and a greater likelihood of thunderstorm development. One interpretation of K index values regarding soaring in the western United States is given in WMO Technical Note 158 and is reproduced in the following table: below -10 no or weak thermals -10 to 5 dry thermals or 1/8 cumulus with moderate thermals 5 to 15 good soaring conditions 15 to 20 good soaring conditions with occasional showers 20 to 30 excellent soaring conditions, but increasing probability of showers and thunderstorms above 30 more than 60 percent probability of thunderstorms Lapse Rate - The change with height of the temperature. Negative values indicate inversions. Lifted Condensation Level - The height to which an air parcel possessing the average dew point in the lowest 4000 feet of the airmass and the forecast maximum temperature must be lifted dry adiabatically to attain saturation. Lifted Index (LI) - The difference between the environmental temperature at a level approximately 18,000 feet above the surface and the temperature of an air parcel lifted dry adiabatically from the surface to its lifted condensation level and then pseudoadiabatically thereafter to this same level. The parcel's initial temperature is the forecast maximum temperature and its dew point is the average dew point in the lowest 4000 feet of the airmass. Negative values are indicative of instability with positive values showing stable conditions. Lift Rate - An experimental estimate of the strength of thermals. It is computed the same way as the maximum rate of lift but uses the actual level rather than the maximum height of thermals in the calculation. Also, none of the empirical adjustments based on cloudiness and K-index are applied to these calculations. Maximum Height of Thermals - The height where the dry adiabat through the forecast maximum temperature intersects the environmental temperature. Maximum Rate of Lift - An estimate of the maximum strength of thermals. It is computed from an empirical formula which combines the expected maximum height of thermals with the difference in the environmental temperatures between the maximum height of thermals and the temperature 4,000 feet above the ground. After this computation, further empirical adjustments are made based on the value of the K-index and the amount and opacity of middle and high level cloudiness expected between the time of trigger temperature and the time of overdevelopment. Middle/High Clouds - The amount and opacity of middle (altostratus, altocumulus) or high (cirrus, cirrostratus, cirrocumulus) clouds. Broken means that between 60% and 90% of the sky is covered by the cloud, with overcast conditions occurring when more than 90% of the sky is covered by the cloud. Thin implies that the clouds are predominantly transparent, meaning that some sunlight is reaching the ground, in contrast to opaque which suggests that little sunlight is reaching the ground. Potential Height of Wave - The minimum of the following two heights: 1. Level above the height of stable layer (or 14,000 feet if none exists) where the wind direction changes by 30 degrees or more 2. Level above the height of stable layer (or 14,000 feet if none exists) where the wind speed no longer increases with height PVA/NVA - Positive vorticity advection (PVA)/negative vorticity advection (NVA) on the 500 millibar isobaric surface (approximately 18,000 feet above mean sea level). Weak PVA has been shown to assist in mountain wave soaring. Soaring Window - The time between the time the trigger temperature is reached and the time of overdevelopment. Thermal Index - The difference between the environmental temperature and the temperature at a particular level determined by following the dry adiabat through the forecast maximum temperature up to that level. Negative values are indicative of thermal lift. Thermal Soaring Index - An adjective rating (for sailplanes) based on the computed maximum rate of lift, and the wind speed and middle and high cloud cover expected during the soaring window (the time of the trigger temperature and the time of overdevelopment) according to the following: Maximum rate of lift Adjective Rating >= 800 fpm Excellent >= 400 and < 800 fpm Good >= 200 and < 400 fpm Fair < 200 fpm Poor Time of Overdevelopment - The time one or more of the following phenomena, which essentially shut off thermal lift, is expected to occur: 1. formation of broken to overcast convective cloud cover 2. formation of scattered to numerous downbursts 3. initiation of widespread precipitation Time of Trigger Temperature - The time the surface temperature is expected to reach the trigger temperature. Trigger Temperature - The surface temperature required to make the first 4000 feet of the atmosphere dry adiabatic. Wave Soaring Index - An empirical, adjective rating (for sailplanes) which attempts to combine a variety of phenomena important in mountain wave soaring into a single index number. Objective points are assigned to these phenomena: wind speed and direction at 14,000 ft MSL, the static stability in the 12,000-18,000 ft MSL layer, the wind speed gradient above the stable layer, jet stream location and frontal and upper trough movements. 042613