066 UXUS97 KBOU 111310 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0709 MDT Tuesday, July 11, 2023 This forecast is for Tuesday, July 11, 2023: If the trigger temperature of 87.6 F/30.9 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1280 ft/min (6.5 m/s) Maximum height of thermals.................. 18669 ft MSL (13340 ft AGL) Forecast maximum temperature................... 95.0 F/35.5 C Time of trigger temperature.................... 1045 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................. 12398 ft MSL (7069 ft AGL) Thermal soaring outlook for Wednesday 07/12.... Excellent 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....................... 41261 ft MSL (35932 ft AGL) Wave soaring outlook for Wednesday 07/12....... Poor Remarks... Sunrise/Sunset.................... 05:41:12 / 20:28:51 MDT Total possible sunshine........... 14 hr 47 min 39 sec (887 min 39 sec) Altitude of sun at 13:05:01 MDT... 72.26 degrees Upper air data from numerical model forecast valid on 07/11/2023 at 0600 MDT Freezing level.................. 16094 ft MSL (10765 ft AGL) Convective condensation level... 19400 ft MSL (14071 ft AGL) Lifted condensation level....... 18925 ft MSL (13597 ft AGL) Lifted index.................... +1.4 K index......................... +17.6 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 -63.7 -82.7 295 32 16 3.4 1.9 M M M M M 45000 -56.5 -69.7 295 48 24 6.4 3.5 M M M M M 40000 -46.8 -52.2 295 53 27 6.4 3.5 M M M M M 38000 -43.0 -45.4 295 48 25 6.4 3.5 M M M M M 36000 -39.1 -38.4 295 42 22 6.4 3.5 M M M M M 34000 -34.8 -30.6 290 40 21 6.4 3.5 M M M M M 32000 -31.0 -23.8 285 38 20 6.2 3.4 M M M M M 30000 -27.5 -17.5 285 38 20 5.9 3.2 48.2 118.8 10.1 M M 29000 -25.7 -14.3 285 38 20 5.9 3.2 46.8 116.3 9.1 M M 28000 -23.7 -10.7 280 38 20 8.5 4.7 45.7 114.2 8.3 M M 27000 -21.3 -6.3 280 37 19 8.2 4.5 45.0 113.0 7.9 M M 26000 -18.8 -1.8 285 36 18 8.2 4.5 44.4 112.0 7.6 M M 25000 -16.3 2.7 285 34 18 8.0 4.4 44.0 111.2 7.3 M M 24000 -14.0 6.8 285 31 16 7.7 4.2 43.1 109.6 6.7 M M 23000 -11.7 10.9 290 28 14 7.7 4.2 42.4 108.3 6.1 M M 22000 -9.4 15.1 300 25 13 6.3 3.5 41.7 107.1 5.6 M M 21000 -8.0 17.6 300 22 11 4.7 2.6 39.8 103.7 4.1 M M 20000 -6.7 19.9 295 19 10 4.9 2.7 38.1 100.6 2.6 M M 19500 -6.0 21.2 295 17 9 5.2 2.9 37.3 99.2 1.8 M M 19000 -5.4 22.3 295 16 8 3.1 1.7 36.4 97.4 0.9 M M 18500 -5.0 23.0 285 15 8 3.5 1.9 35.2 95.4 -0.1 1278 6.5 18000 -4.2 24.4 275 14 7 6.7 3.7 33.9 93.0 -1.5 1230 6.2 17500 -3.2 26.2 270 14 7 6.7 3.7 33.3 92.0 -2.0 1188 6.0 17000 -2.3 27.9 265 14 7 8.1 4.5 32.8 91.1 -2.6 1146 5.8 16500 -0.9 30.4 270 13 7 9.6 5.2 32.8 91.0 -2.6 1088 5.5 16000 0.5 32.9 270 12 6 9.7 5.3 32.8 91.0 -2.7 1030 5.2 15500 2.0 35.6 275 12 6 9.8 5.4 32.8 91.0 -2.7 972 4.9 15000 3.4 38.1 275 13 7 9.8 5.4 32.8 91.0 -2.7 913 4.6 14500 4.9 40.8 280 13 7 9.4 5.2 32.7 90.9 -2.7 855 4.3 14000 6.3 43.3 280 14 7 9.4 5.2 32.7 90.8 -2.8 799 4.1 13500 7.7 45.9 285 14 7 9.4 5.2 32.6 90.7 -2.9 742 3.8 13000 9.1 48.4 285 14 7 9.5 5.2 32.6 90.7 -2.9 684 3.5 12500 10.5 50.9 290 15 7 9.3 5.1 32.6 90.6 -3.0 627 3.2 12000 11.9 53.4 290 15 8 9.2 5.0 32.5 90.4 -3.1 571 2.9 11500 13.2 55.8 290 15 8 9.2 5.0 32.4 90.3 -3.2 516 2.6 11000 14.6 58.3 295 15 7 8.9 4.9 32.3 90.1 -3.3 460 2.3 10500 16.0 60.8 295 14 7 4.1 2.3 32.2 90.0 -3.4 403 2.0 10250 16.1 61.0 295 14 7 5.1 2.8 31.6 88.8 -4.0 393 2.0 10000 16.9 62.4 295 14 7 12.2 6.7 31.6 89.0 -4.0 361 1.8 9750 17.7 63.9 295 13 7 10.7 5.9 31.7 89.1 -3.9 330 1.7 9500 18.5 65.3 295 13 7 9.6 5.2 31.8 89.3 -3.8 299 1.5 9250 19.1 66.4 295 13 6 7.1 3.9 31.7 89.0 -4.0 274 1.4 9000 19.7 67.5 295 12 6 8.4 4.6 31.5 88.7 -4.2 249 1.3 8750 20.3 68.5 290 12 6 9.4 5.2 31.5 88.6 -4.2 222 1.1 8500 21.0 69.8 290 12 6 8.8 4.8 31.4 88.5 -4.3 194 1.0 8250 21.6 70.9 285 12 6 8.4 4.6 31.3 88.4 -4.4 169 0.9 8000 22.2 72.0 290 11 6 7.8 4.3 31.2 88.2 -4.6 144 0.7 7750 22.7 72.9 285 11 6 7.6 4.2 31.0 87.8 -4.8 120 0.6 7500 23.3 73.9 280 11 6 6.9 3.8 30.8 87.5 -5.0 97 0.5 7250 23.7 74.7 280 12 6 6.1 3.3 30.6 87.0 -5.3 75 0.4 7000 24.2 75.6 280 12 6 5.9 3.3 30.3 86.5 -5.6 55 0.3 6750 24.6 76.3 275 12 6 4.7 2.6 30.0 85.9 -5.9 36 0.2 6500 24.7 76.5 270 11 6 -1.4 -0.8 29.4 84.9 -6.5 24 0.1 6250 24.3 75.7 270 11 6 -6.6 -3.6 28.3 82.9 -7.7 29 0.1 6000 23.9 75.0 265 11 6 -1.7 -1.0 27.2 80.9 -8.8 33 0.2 5750 23.6 74.5 265 10 5 -12.9 -7.1 26.2 79.1 -9.9 36 0.2 5500 21.2 70.2 255 6 3 -48.6 -26.7 23.2 73.7 -13.0 100 0.5 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 07/11/2023 at 0900 MDT | 07/11/2023 at 1200 MDT | CAPE... +3.7 LI... +2.6 | CAPE... 0.0 LI... +2.2 CINH... -16.4 K Index... +16.2' | CINH... -0.1 K Index... +11.1' | 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 -64.0 -83.2 290 30 16 3.8 2.1 | -64.6 -84.3 280 29 15 3.4 1.9 45000 -56.5 -69.7 290 46 24 6.3 3.5 | -57.1 -70.8 285 45 23 6.8 3.8 40000 -46.9 -52.4 295 52 27 6.5 3.5 | -46.9 -52.4 285 53 27 6.4 3.5 38000 -43.0 -45.4 295 49 25 6.5 3.5 | -43.1 -45.6 285 51 26 6.4 3.5 36000 -39.2 -38.6 295 46 23 6.5 3.6 | -39.2 -38.6 285 50 26 6.6 3.6 34000 -35.2 -31.4 290 42 22 6.6 3.6 | -35.2 -31.4 285 44 23 6.7 3.7 32000 -30.7 -23.3 290 39 20 6.4 3.5 | -30.7 -23.3 285 38 19 6.5 3.6 30000 -27.1 -16.8 285 39 20 6.0 3.3 | -26.9 -16.4 280 37 19 6.2 3.4 29000 -25.3 -13.5 285 40 20 6.0 3.3 | -25.0 -13.0 280 36 19 6.2 3.4 28000 -23.4 -10.1 280 39 20 7.8 4.3 | -23.1 -9.6 275 36 18 7.0 3.8 27000 -21.1 -6.0 280 37 19 7.6 4.2 | -21.0 -5.8 275 35 18 6.9 3.8 26000 -18.8 -1.8 280 34 18 7.6 4.2 | -19.0 -2.2 270 34 17 6.9 3.8 25000 -16.5 2.3 280 32 16 7.4 4.1 | -16.9 1.6 265 33 17 7.1 3.9 24000 -14.3 6.3 285 28 15 7.3 4.0 | -14.7 5.5 265 30 15 7.3 4.0 23000 -12.2 10.0 285 25 13 7.3 4.0 | -12.5 9.5 260 27 14 7.3 4.0 22000 -10.0 14.0 285 22 11 6.3 3.5 | -10.3 13.5 260 24 12 6.6 3.6 21000 -8.4 16.9 285 20 10 5.5 3.0 | -8.5 16.7 260 23 12 6.1 3.3 20000 -6.7 19.9 280 17 9 5.6 3.1 | -6.7 19.9 260 22 11 6.1 3.4 19500 -5.9 21.4 280 16 8 5.7 3.2 | -5.8 21.6 260 21 11 6.2 3.4 19000 -5.2 22.6 275 16 8 4.5 2.5 | -4.9 23.2 260 21 11 6.6 3.6 18500 -4.6 23.7 270 15 8 4.8 2.6 | -3.9 25.0 260 21 11 6.6 3.6 18000 -3.9 25.0 265 15 8 5.7 3.1 | -3.0 26.6 260 21 11 6.9 3.8 17500 -2.5 27.5 260 15 8 6.7 3.7 | -1.9 28.6 265 21 11 7.1 3.9 17000 -1.6 29.1 255 15 8 7.6 4.2 | -0.9 30.4 265 21 11 7.1 3.9 16500 -0.4 31.3 255 14 7 8.3 4.5 | 0.6 33.1 265 20 11 6.6 3.6 16000 0.8 33.4 260 12 6 8.4 4.6 | 1.5 34.7 270 20 10 6.9 3.8 15500 2.1 35.8 265 11 6 8.5 4.7 | 2.6 36.7 270 19 10 8.2 4.5 15000 3.3 37.9 265 11 6 8.5 4.7 | 3.8 38.8 275 18 9 8.1 4.5 14500 4.6 40.3 270 10 5 9.2 5.0 | 5.0 41.0 275 17 9 8.9 4.9 14000 6.0 42.8 275 9 5 9.2 5.0 | 6.3 43.3 275 15 8 8.9 4.9 13500 7.4 45.3 280 9 5 9.3 5.1 | 7.6 45.7 280 14 7 9.0 4.9 13000 8.7 47.7 285 9 4 9.3 5.1 | 8.9 48.0 280 13 7 9.0 5.0 12500 10.1 50.2 290 8 4 9.3 5.1 | 10.3 50.5 280 12 6 9.1 5.0 12000 11.5 52.7 290 8 4 9.4 5.1 | 11.6 52.9 280 11 6 9.2 5.0 11500 13.0 55.4 295 9 4 9.2 5.1 | 13.0 55.4 285 10 5 9.2 5.0 11000 14.3 57.7 295 9 5 8.7 4.8 | 14.3 57.7 285 10 5 8.9 4.9 10500 15.7 60.3 295 10 5 4.6 2.5 | 15.7 60.3 285 9 5 3.9 2.1 10250 15.8 60.4 310 7 4 5.8 3.2 | 15.8 60.4 285 8 4 5.4 3.0 10000 16.7 62.1 300 8 4 12.1 6.7 | 16.7 62.1 290 8 4 13.2 7.3 9750 17.5 63.5 300 10 5 11.0 6.0 | 17.5 63.5 290 8 4 11.8 6.5 9500 18.3 64.9 295 11 6 9.1 5.0 | 18.4 65.1 290 9 4 9.8 5.4 9250 18.8 65.8 295 10 5 6.8 3.7 | 19.0 66.2 290 8 4 8.0 4.4 9000 19.4 66.9 295 10 5 8.6 4.7 | 19.7 67.5 290 8 4 10.4 5.7 8750 20.1 68.2 295 11 6 9.7 5.3 | 20.5 68.9 295 8 4 11.2 6.1 8500 20.8 69.4 290 12 6 8.2 4.5 | 21.3 70.3 295 8 4 10.1 5.5 8250 21.3 70.3 290 12 6 6.4 3.5 | 21.9 71.4 295 8 4 8.7 4.7 8000 21.7 71.1 290 11 6 7.4 4.0 | 22.6 72.7 295 7 4 9.8 5.4 7750 22.3 72.1 285 12 6 8.7 4.8 | 23.4 74.1 295 7 4 10.9 6.0 7500 22.9 73.2 285 12 6 6.5 3.6 | 24.1 75.4 295 8 4 9.5 5.2 7250 23.3 73.9 285 11 6 4.2 2.3 | 24.8 76.6 300 7 4 8.2 4.5 7000 23.6 74.5 280 10 5 6.3 3.5 | 25.4 77.7 300 7 4 9.7 5.3 6750 24.2 75.6 275 10 5 9.3 5.1 | 26.3 79.3 300 7 4 12.1 6.7 6500 24.8 76.6 275 10 5 6.0 3.3 | 27.2 81.0 300 7 4 11.3 6.2 6250 25.0 77.0 265 8 4 3.1 1.7 | 27.9 82.2 300 7 4 10.6 5.8 6000 25.3 77.5 255 7 3 3.7 2.0 | 28.7 83.7 300 7 3 9.6 5.2 5750 25.5 77.9 250 6 3 6.4 3.5 | 29.5 85.1 300 6 3 14.3 7.8 5500 26.1 79.0 245 6 3 12.2 6.7 | 31.0 87.8 300 6 3 27.3 15.0 07/11/2023 at 1500 MDT | 07/11/2023 at 1800 MDT | CAPE... 0.0 LI... +1.5 | CAPE... 0.0 LI... +0.5 CINH... -0.1 K Index... +15.6' | CINH... 0.0 K Index... +11.9' | 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 -64.7 -84.5 270 34 17 3.2 1.8 | -64.3 -83.7 270 34 17 4.0 2.2 45000 -57.3 -71.1 280 46 24 7.0 3.8 | -56.6 -69.9 275 48 25 6.2 3.4 40000 -47.0 -52.6 280 52 27 6.6 3.6 | -47.2 -53.0 280 59 30 6.4 3.5 38000 -43.0 -45.4 285 53 27 6.6 3.6 | -43.4 -46.1 285 59 30 6.4 3.5 36000 -39.1 -38.4 285 53 27 6.7 3.7 | -39.6 -39.3 285 59 31 6.6 3.6 34000 -35.0 -31.0 285 49 25 6.9 3.8 | -35.5 -31.9 280 56 29 6.8 3.8 32000 -30.3 -22.5 285 45 23 6.9 3.8 | -30.9 -23.6 280 53 27 6.8 3.7 30000 -26.2 -15.2 280 39 20 6.8 3.7 | -26.8 -16.2 280 47 24 6.7 3.7 29000 -24.2 -11.6 280 36 19 6.8 3.7 | -24.8 -12.6 275 44 23 6.7 3.7 28000 -22.2 -8.0 275 34 18 5.8 3.2 | -22.8 -9.0 275 41 21 7.2 3.9 27000 -20.5 -4.9 270 34 17 5.9 3.2 | -20.7 -5.3 270 39 20 7.1 3.9 26000 -18.7 -1.7 265 33 17 5.9 3.2 | -18.5 -1.3 270 37 19 7.1 3.9 25000 -16.9 1.6 260 34 17 6.3 3.4 | -16.4 2.5 265 35 18 6.1 3.4 24000 -14.9 5.2 255 31 16 6.6 3.6 | -14.8 5.4 265 33 17 5.2 2.9 23000 -13.0 8.6 250 29 15 6.6 3.6 | -13.3 8.1 260 31 16 5.3 2.9 22000 -11.0 12.2 245 27 14 6.6 3.6 | -11.7 10.9 255 30 15 5.9 3.2 21000 -9.1 15.6 250 25 13 6.6 3.6 | -9.9 14.2 255 27 14 6.3 3.5 20000 -7.1 19.2 250 23 12 6.6 3.6 | -8.0 17.6 250 25 13 6.5 3.5 19500 -6.1 21.0 255 22 11 6.7 3.7 | -7.1 19.2 250 24 12 6.6 3.6 19000 -5.2 22.6 255 22 11 6.5 3.6 | -6.0 21.2 250 23 12 8.7 4.7 18500 -4.2 24.4 260 22 11 6.6 3.6 | -4.8 23.4 255 22 11 8.5 4.7 18000 -3.3 26.1 265 22 12 7.2 4.0 | -3.5 25.7 255 21 11 8.6 4.7 17500 -1.7 28.9 265 23 12 7.7 4.2 | -1.6 29.1 255 20 10 8.6 4.7 17000 -0.5 31.1 265 23 12 8.2 4.5 | -0.4 31.3 260 19 10 9.0 4.9 16500 0.7 33.3 265 22 11 8.5 4.7 | 1.0 33.8 260 18 10 9.2 5.0 16000 1.9 35.4 265 21 11 8.6 4.7 | 2.4 36.3 265 18 9 9.3 5.1 15500 3.2 37.8 265 20 10 9.2 5.0 | 3.8 38.8 265 17 9 9.4 5.2 15000 4.6 40.3 265 19 10 9.1 5.0 | 5.2 41.4 265 16 8 9.4 5.2 14500 5.9 42.6 270 17 9 9.2 5.0 | 6.5 43.7 270 16 8 9.3 5.1 14000 7.3 45.1 270 16 8 9.2 5.1 | 7.9 46.2 270 15 8 9.3 5.1 13500 8.6 47.5 270 15 8 9.1 5.0 | 9.3 48.7 275 15 8 9.4 5.1 13000 10.0 50.0 270 14 7 9.1 5.0 | 10.7 51.3 275 14 7 9.4 5.2 12500 11.3 52.3 275 12 6 9.1 5.0 | 12.1 53.8 275 13 7 9.4 5.2 12000 12.6 54.7 275 11 5 9.0 5.0 | 13.5 56.3 280 12 6 9.4 5.1 11500 14.0 57.2 280 9 5 9.2 5.0 | 14.9 58.8 280 11 6 9.2 5.1 11000 15.4 59.7 280 8 4 9.1 5.0 | 16.2 61.2 280 10 5 8.8 4.8 10500 16.8 62.2 285 7 4 5.3 2.9 | 17.6 63.7 285 9 4 4.9 2.7 10250 17.0 62.6 290 7 4 6.8 3.7 | 17.8 64.0 290 9 5 6.4 3.5 10000 17.9 64.2 290 7 4 12.9 7.1 | 18.6 65.5 290 9 4 12.7 6.9 9750 18.7 65.7 290 7 3 11.8 6.5 | 19.5 67.1 290 8 4 11.4 6.3 9500 19.6 67.3 295 7 3 10.1 5.5 | 20.3 68.5 295 8 4 10.3 5.6 9250 20.3 68.5 295 6 3 8.6 4.7 | 21.0 69.8 295 9 4 9.1 5.0 9000 21.0 69.8 300 6 3 10.6 5.8 | 21.7 71.1 300 8 4 10.4 5.7 8750 21.8 71.2 300 6 3 11.1 6.1 | 22.5 72.5 300 8 4 10.6 5.8 8500 22.6 72.7 300 6 3 10.3 5.6 | 23.3 73.9 300 7 4 10.1 5.6 8250 23.3 73.9 305 6 3 9.1 5.0 | 24.0 75.2 300 8 4 9.4 5.1 8000 24.0 75.2 305 6 3 9.8 5.4 | 24.7 76.5 300 9 4 9.8 5.4 7750 24.8 76.6 305 6 3 10.8 5.9 | 25.4 77.7 305 8 4 10.5 5.8 7500 25.6 78.1 305 5 3 9.6 5.3 | 26.2 79.2 305 7 4 9.4 5.2 7250 26.2 79.2 310 6 3 8.3 4.6 | 26.8 80.2 305 8 4 8.0 4.4 7000 26.9 80.4 310 6 3 9.6 5.3 | 27.5 81.5 305 8 4 9.4 5.1 6750 27.7 81.9 310 6 3 11.9 6.5 | 28.3 82.9 305 8 4 11.8 6.5 6500 28.6 83.5 310 5 3 11.4 6.2 | 29.2 84.6 305 7 4 11.1 6.1 6250 29.4 84.9 315 5 3 10.8 5.9 | 29.9 85.8 305 7 4 10.0 5.5 6000 30.2 86.4 315 5 3 9.7 5.3 | 30.7 87.3 305 8 4 9.7 5.3 5750 30.9 87.6 315 5 3 12.8 7.0 | 31.4 88.5 305 8 4 10.5 5.8 5500 32.3 90.1 315 5 2 25.1 13.7 | 32.3 90.1 310 6 3 15.3 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. CINH (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