Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
980 UXUS97 KBOU 240051 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 1851 MDT Sunday, June 23, 2024 This forecast is for Monday, June 24, 2024: If the trigger temperature of 85.1 F/29.5 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1249 ft/min (6.3 m/s) Maximum height of thermals.................. 18853 ft MSL (13541 ft AGL) Forecast maximum temperature................... 96.0 F/36.0 C Time of trigger temperature.................... 0930 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................. 14545 ft MSL (9233 ft AGL) Thermal soaring outlook for Tuesday 06/25...... 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....................... 41163 ft MSL (35851 ft AGL) Wave soaring outlook for Tuesday 06/25......... Fair Remarks... None Sunrise/Sunset.................... 05:32:39 / 20:31:34 MDT Total possible sunshine........... 14 hr 58 min 55 sec (898 min 55 sec) Altitude of sun at 13:02:07 MDT... 73.61 degrees Upper air data from numerical model forecast valid on 06/24/2024 at 0600 MDT Freezing level.................. 16496 ft MSL (11184 ft AGL) Convective condensation level... 18028 ft MSL (12716 ft AGL) Lifted condensation level....... 18492 ft MSL (13181 ft AGL) Lifted index.................... -1.8 K index......................... +22.3 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 -63.4 -82.1 275 42 22 3.4 1.9 M M M M M 45000 -57.1 -70.8 270 58 30 5.5 3.0 M M M M M 40000 -48.2 -54.8 270 65 33 6.3 3.4 M M M M M 38000 -44.5 -48.1 270 61 32 6.3 3.4 M M M M M 36000 -40.8 -41.4 270 58 30 6.2 3.4 M M M M M 34000 -37.3 -35.1 270 48 25 5.8 3.2 M M M M M 32000 -33.8 -28.8 270 38 20 5.7 3.1 M M M M M 30000 -29.9 -21.8 270 34 18 6.6 3.6 46.1 115.0 8.0 M M 29000 -27.5 -17.5 270 33 17 6.6 3.6 44.6 112.3 7.0 M M 28000 -25.4 -13.7 270 31 16 7.9 4.3 43.6 110.5 6.2 M M 27000 -23.1 -9.6 270 29 15 7.8 4.3 42.8 109.0 5.6 M M 26000 -20.8 -5.4 265 27 14 7.8 4.3 42.0 107.7 5.1 M M 25000 -18.4 -1.1 265 25 13 7.9 4.3 41.4 106.6 4.7 M M 24000 -16.1 3.0 265 22 11 8.0 4.4 40.7 105.2 4.1 M M 23000 -13.7 7.3 260 18 9 8.0 4.4 40.0 104.1 3.6 M M 22000 -11.3 11.7 255 15 8 7.1 3.9 39.5 103.1 3.2 M M 21000 -9.4 15.1 255 13 7 6.4 3.5 38.2 100.8 2.1 M M 20000 -7.5 18.5 260 11 6 6.4 3.5 37.1 98.7 1.1 M M 19500 -6.6 20.1 265 11 5 6.4 3.5 36.5 97.8 0.6 M M 19000 -5.6 21.9 270 10 5 7.1 3.9 36.0 96.9 0.2 M M 18500 -4.6 23.7 275 9 5 7.1 3.9 35.6 96.0 -0.2 1223 6.2 18000 -3.6 25.5 280 9 5 7.4 4.1 35.1 95.3 -0.7 1177 6.0 17500 -2.5 27.5 280 9 5 7.7 4.2 34.8 94.6 -1.1 1130 5.7 17000 -1.4 29.5 285 9 5 7.7 4.2 34.4 94.0 -1.4 1082 5.5 16500 -0.3 31.5 285 9 5 8.1 4.5 34.1 93.4 -1.8 1034 5.3 16000 0.9 33.6 285 9 5 8.2 4.5 33.8 92.9 -2.1 985 5.0 15500 2.6 36.7 285 8 4 8.5 4.7 33.5 92.3 -2.6 910 4.6 15000 3.8 38.8 285 8 4 8.5 4.7 33.3 91.9 -2.8 859 4.4 14500 5.1 41.2 285 7 4 8.7 4.8 33.1 91.6 -3.1 807 4.1 14000 6.3 43.3 280 6 3 8.7 4.8 32.9 91.2 -3.3 755 3.8 13500 7.6 45.7 270 6 3 8.3 4.6 32.7 90.9 -3.5 702 3.6 13000 8.8 47.8 260 6 3 8.2 4.5 32.5 90.5 -3.8 652 3.3 12500 10.0 50.0 250 5 3 8.2 4.5 32.2 90.0 -4.1 602 3.1 12000 11.2 52.2 245 5 3 8.1 4.5 32.0 89.5 -4.3 551 2.8 11500 12.4 54.3 235 5 3 8.0 4.4 31.7 89.1 -4.6 500 2.5 11000 13.6 56.5 240 5 3 7.6 4.2 31.4 88.5 -4.9 450 2.3 10500 14.7 58.5 240 5 3 5.3 2.9 31.1 88.0 -5.2 400 2.0 10250 15.0 59.0 240 5 3 6.1 3.3 30.7 87.2 -5.6 384 1.9 10000 15.7 60.3 250 5 2 9.7 5.3 30.6 87.1 -5.7 355 1.8 9750 16.4 61.5 255 5 2 8.8 4.8 30.5 87.0 -5.7 327 1.7 9500 17.1 62.8 265 5 2 8.7 4.8 30.5 86.9 -5.8 299 1.5 9250 17.8 64.0 275 4 2 8.6 4.7 30.4 86.7 -5.8 271 1.4 9000 18.5 65.3 285 4 2 9.5 5.2 30.3 86.6 -5.9 243 1.2 8750 19.2 66.6 295 4 2 9.8 5.4 30.3 86.6 -5.9 213 1.1 8500 20.0 68.0 305 5 2 9.8 5.4 30.3 86.6 -5.9 183 0.9 8250 20.7 69.3 310 5 3 10.5 5.8 30.4 86.6 -5.9 155 0.8 8000 21.4 70.5 310 5 3 9.2 5.0 30.4 86.7 -5.9 126 0.6 7750 21.9 71.4 310 6 3 7.7 4.2 30.3 86.5 -6.2 103 0.5 7500 22.4 72.3 310 7 3 8.0 4.4 30.1 86.2 -6.4 81 0.4 7250 23.0 73.4 310 8 4 8.1 4.4 30.0 86.0 -6.6 57 0.3 7000 23.5 74.3 310 10 5 8.1 4.5 29.9 85.8 -6.8 33 0.2 6750 24.1 75.4 310 12 6 6.9 3.8 29.7 85.5 -7.0 9 0.0 6500 24.3 75.7 310 13 7 -1.9 -1.0 29.2 84.6 -7.5 M M 6250 23.8 74.8 300 12 6 -8.3 -4.5 28.0 82.4 -8.7 2 0.0 6000 23.3 73.9 290 12 6 -4.1 -2.3 26.8 80.2 -10.0 9 0.0 5750 23.0 73.4 280 13 7 -9.9 -5.4 25.7 78.2 -11.1 13 0.1 5500 21.4 70.5 265 10 5 -30.5 -16.7 23.5 74.3 -13.4 52 0.3 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/24/2024 at 0900 MDT | 06/24/2024 at 1200 MDT | CAPE... +88.1 LI... -0.8 | CAPE... +217.3 LI... -0.9 CINH... -117.8 K Index... +22.1 | CINH... -12.7 K Index... +23.3 | 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 -62.9 -81.2 270 38 20 3.2 1.7 | -62.6 -80.7 270 37 19 3.6 2.0 45000 -56.9 -70.4 270 56 29 5.4 3.0 | -56.5 -69.7 275 56 29 4.9 2.7 40000 -48.7 -55.7 270 66 34 5.9 3.3 | -48.5 -55.3 270 70 36 5.9 3.2 38000 -44.7 -48.5 270 63 32 5.9 3.3 | -44.9 -48.8 270 66 34 5.9 3.2 36000 -41.2 -42.2 275 60 31 6.0 3.3 | -41.4 -42.5 270 62 32 6.0 3.3 34000 -37.5 -35.5 270 52 27 6.1 3.3 | -37.4 -35.3 270 54 28 6.7 3.7 32000 -33.9 -29.0 270 44 23 6.1 3.3 | -33.4 -28.1 270 45 23 6.8 3.7 30000 -30.0 -22.0 265 36 19 6.4 3.5 | -29.7 -21.5 270 38 19 5.3 2.9 29000 -28.1 -18.6 260 33 17 6.4 3.5 | -28.1 -18.6 270 35 18 5.3 2.9 28000 -26.1 -15.0 255 29 15 7.2 3.9 | -26.4 -15.5 270 32 16 7.7 4.2 27000 -23.9 -11.0 255 28 15 7.3 4.0 | -24.1 -11.4 270 30 16 7.5 4.1 26000 -21.7 -7.1 260 27 14 7.3 4.0 | -21.9 -7.4 270 29 15 7.5 4.1 25000 -19.6 -3.3 260 26 14 7.2 4.0 | -19.6 -3.3 270 27 14 7.0 3.8 24000 -17.6 0.3 260 24 12 6.7 3.7 | -17.7 0.1 270 25 13 6.3 3.5 23000 -15.6 3.9 260 21 11 6.7 3.7 | -15.9 3.4 265 22 12 6.4 3.5 22000 -13.6 7.5 260 18 9 6.9 3.8 | -14.0 6.8 265 20 10 7.4 4.1 21000 -11.6 11.1 260 15 8 7.2 3.9 | -11.7 10.9 265 18 9 8.1 4.5 20000 -9.0 15.8 255 11 6 7.4 4.0 | -9.3 15.3 265 16 8 8.2 4.5 19500 -7.9 17.8 255 10 5 7.8 4.3 | -8.1 17.4 265 14 7 8.2 4.5 19000 -6.7 19.9 250 9 4 8.3 4.6 | -6.9 19.6 265 14 7 8.0 4.4 18500 -5.5 22.1 245 8 4 8.3 4.6 | -5.8 21.6 265 13 6 8.1 4.5 18000 -4.3 24.3 245 7 4 8.8 4.8 | -4.6 23.7 265 12 6 8.4 4.6 17500 -3.0 26.6 245 6 3 8.8 4.8 | -3.4 25.9 270 11 6 8.6 4.7 17000 -1.7 28.9 245 6 3 8.7 4.8 | -2.1 28.2 270 11 5 8.6 4.7 16500 -0.4 31.3 245 5 3 8.6 4.7 | -0.1 31.8 275 10 5 8.8 4.9 16000 0.9 33.6 250 4 2 8.6 4.7 | 1.2 34.2 275 9 5 8.9 4.9 15500 2.2 36.0 255 4 2 9.2 5.1 | 2.5 36.5 275 9 4 9.2 5.1 15000 3.6 38.5 260 3 2 9.2 5.0 | 3.9 39.0 280 8 4 9.2 5.1 14500 5.0 41.0 270 3 1 9.2 5.0 | 5.2 41.4 280 8 4 9.3 5.1 14000 6.3 43.3 285 3 2 9.2 5.0 | 6.6 43.9 285 7 4 9.3 5.1 13500 7.7 45.9 295 3 2 8.9 4.9 | 8.0 46.4 290 7 4 9.2 5.0 13000 9.0 48.2 305 4 2 8.8 4.8 | 9.3 48.7 295 7 4 9.1 5.0 12500 10.3 50.5 315 4 2 8.7 4.8 | 10.7 51.3 300 7 4 9.1 5.0 12000 11.6 52.9 320 5 2 8.5 4.7 | 12.0 53.6 305 7 3 9.1 5.0 11500 12.9 55.2 325 5 3 8.5 4.7 | 13.3 55.9 310 6 3 9.1 5.0 11000 14.1 57.4 325 6 3 8.3 4.5 | 14.7 58.5 310 6 3 8.8 4.8 10500 15.4 59.7 325 7 4 4.4 2.4 | 16.0 60.8 315 6 3 5.1 2.8 10250 15.6 60.1 325 7 4 5.9 3.2 | 16.2 61.2 310 6 3 6.7 3.7 10000 16.4 61.5 325 8 4 12.2 6.7 | 17.1 62.8 315 6 3 12.8 7.0 9750 17.2 63.0 325 9 4 10.8 5.9 | 17.9 64.2 315 6 3 11.7 6.4 9500 18.0 64.4 325 9 5 9.9 5.4 | 18.8 65.8 315 6 3 10.1 5.5 9250 18.7 65.7 325 10 5 8.2 4.5 | 19.4 66.9 315 6 3 8.7 4.8 9000 19.3 66.7 320 10 5 9.3 5.1 | 20.2 68.4 315 6 3 10.6 5.8 8750 20.0 68.0 320 11 6 10.1 5.5 | 21.0 69.8 315 6 3 11.0 6.0 8500 20.7 69.3 315 11 6 9.4 5.1 | 21.8 71.2 320 6 3 10.2 5.6 8250 21.3 70.3 315 12 6 8.7 4.8 | 22.5 72.5 320 6 3 9.1 5.0 8000 22.0 71.6 315 13 7 8.3 4.6 | 23.2 73.8 320 5 3 9.9 5.4 7750 22.5 72.5 310 13 7 8.2 4.5 | 24.0 75.2 320 6 3 10.9 6.0 7500 23.1 73.6 310 13 7 7.8 4.3 | 24.7 76.5 320 6 3 9.6 5.3 7250 23.7 74.7 310 14 7 7.1 3.9 | 25.4 77.7 320 5 3 8.1 4.5 7000 24.2 75.6 310 14 7 7.8 4.3 | 26.0 78.8 325 5 3 9.6 5.3 6750 24.9 76.8 305 14 7 9.3 5.1 | 26.8 80.2 325 5 3 12.1 6.6 6500 25.5 77.9 305 13 7 7.4 4.1 | 27.7 81.9 320 5 3 11.6 6.4 6250 26.0 78.8 300 12 6 6.0 3.3 | 28.6 83.5 325 5 3 11.0 6.1 6000 26.4 79.5 295 11 6 5.3 2.9 | 29.4 84.9 325 5 3 9.8 5.4 5750 26.7 80.1 290 9 5 6.7 3.7 | 30.1 86.2 325 5 2 13.9 7.6 5500 27.5 81.5 285 7 4 14.8 8.1 | 31.7 89.1 325 5 2 28.2 15.5 06/24/2024 at 1500 MDT | 06/24/2024 at 1800 MDT | CAPE... +257.3 LI... -0.6 | CAPE... +265.4 LI... -0.8 CINH... -26.2 K Index... +24.3 | CINH... -30.8 K Index... +25.1 | 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 -63.0 -81.4 265 45 23 3.7 2.0 | -63.3 -81.9 275 51 26 4.4 2.4 45000 -56.6 -69.9 275 62 32 4.9 2.7 | -56.5 -69.7 275 66 34 4.9 2.7 40000 -48.9 -56.0 275 73 38 6.2 3.4 | -48.6 -55.5 280 75 39 5.6 3.1 38000 -45.2 -49.4 275 68 35 6.2 3.4 | -45.3 -49.5 280 69 36 5.6 3.1 36000 -41.6 -42.9 275 62 32 6.3 3.4 | -41.9 -43.4 280 64 33 5.8 3.2 34000 -37.5 -35.5 275 54 28 6.8 3.7 | -38.1 -36.6 280 55 28 6.4 3.5 32000 -33.5 -28.3 275 45 23 6.8 3.7 | -34.3 -29.7 280 46 23 6.3 3.5 30000 -29.6 -21.3 275 38 20 5.6 3.0 | -30.3 -22.5 280 40 21 6.7 3.7 29000 -27.9 -18.2 275 35 18 5.5 3.0 | -27.8 -18.0 280 38 19 6.7 3.7 28000 -26.1 -15.0 275 33 17 8.8 4.8 | -25.7 -14.3 280 36 18 7.7 4.2 27000 -23.5 -10.3 270 31 16 8.4 4.6 | -23.4 -10.1 280 34 18 7.6 4.2 26000 -21.0 -5.8 270 29 15 8.4 4.6 | -21.1 -6.0 280 33 17 7.7 4.2 25000 -18.5 -1.3 265 27 14 7.4 4.1 | -18.9 -2.0 280 31 16 7.6 4.1 24000 -16.6 2.1 270 26 13 6.1 3.4 | -16.7 1.9 280 29 15 7.5 4.1 23000 -14.8 5.4 275 25 13 6.1 3.4 | -14.5 5.9 280 26 13 7.6 4.2 22000 -13.0 8.6 280 25 13 7.2 4.0 | -12.3 9.9 280 24 12 7.6 4.2 21000 -10.6 12.9 285 24 13 8.2 4.5 | -10.0 14.0 285 23 12 7.5 4.1 20000 -8.1 17.4 290 24 12 8.2 4.5 | -7.8 18.0 290 21 11 7.5 4.1 19500 -6.9 19.6 290 24 12 8.3 4.5 | -6.7 19.9 290 21 11 7.6 4.2 19000 -5.8 21.6 295 23 12 7.6 4.2 | -5.5 22.1 290 21 11 8.4 4.6 18500 -4.7 23.5 295 22 11 7.9 4.3 | -4.3 24.3 290 20 10 8.4 4.6 18000 -3.6 25.5 300 21 11 8.3 4.6 | -3.0 26.6 295 20 10 8.8 4.8 17500 -2.4 27.7 300 19 10 8.6 4.7 | -1.7 28.9 295 18 9 9.0 4.9 17000 -0.6 30.9 305 18 9 8.8 4.8 | -0.4 31.3 295 17 9 9.0 5.0 16500 0.7 33.3 305 17 9 8.9 4.9 | 0.9 33.6 300 15 8 9.0 4.9 16000 2.0 35.6 310 16 8 8.9 4.9 | 2.2 36.0 300 14 7 9.0 5.0 15500 3.3 37.9 310 14 7 8.7 4.8 | 3.5 38.3 300 12 6 9.0 4.9 15000 4.6 40.3 315 13 7 8.7 4.8 | 4.8 40.6 305 11 6 9.0 4.9 14500 5.9 42.6 315 12 6 9.2 5.0 | 6.7 44.1 310 9 5 9.1 5.0 14000 7.2 45.0 320 11 6 9.2 5.0 | 8.0 46.4 315 8 4 9.1 5.0 13500 8.6 47.5 320 10 5 8.9 4.9 | 9.4 48.9 320 7 4 8.8 4.8 13000 9.9 49.8 320 9 4 8.8 4.8 | 10.6 51.1 325 6 3 8.8 4.8 12500 11.2 52.2 325 8 4 9.0 4.9 | 11.9 53.4 330 6 3 8.8 4.8 12000 12.5 54.5 325 7 4 9.3 5.1 | 13.3 55.9 335 6 3 8.9 4.9 11500 13.9 57.0 325 6 3 9.1 5.0 | 14.6 58.3 335 6 3 8.8 4.8 11000 15.2 59.4 320 6 3 8.5 4.6 | 15.9 60.6 335 6 3 8.5 4.6 10500 16.4 61.5 320 5 3 7.0 3.8 | 17.1 62.8 335 6 3 5.8 3.2 10250 16.9 62.4 320 5 3 8.3 4.6 | 17.5 63.5 335 5 3 7.1 3.9 10000 17.7 63.9 320 5 3 11.3 6.2 | 18.3 64.9 335 6 3 11.5 6.3 9750 18.5 65.3 320 5 3 10.6 5.8 | 19.1 66.4 330 6 3 10.5 5.7 9500 19.2 66.6 320 5 3 10.3 5.7 | 19.9 67.8 330 6 3 10.3 5.7 9250 20.0 68.0 315 5 3 9.9 5.4 | 20.6 69.1 330 6 3 9.8 5.4 9000 20.8 69.4 315 5 3 10.3 5.7 | 21.3 70.3 330 6 3 10.0 5.5 8750 21.5 70.7 315 5 3 10.4 5.7 | 22.1 71.8 325 6 3 9.9 5.4 8500 22.3 72.1 315 5 3 10.4 5.7 | 22.8 73.0 325 6 3 10.2 5.6 8250 23.1 73.6 315 5 3 10.6 5.8 | 23.6 74.5 325 6 3 10.9 6.0 8000 23.8 74.8 315 5 3 9.7 5.3 | 24.4 75.9 325 6 3 9.9 5.4 7750 24.5 76.1 310 5 3 8.5 4.7 | 25.1 77.2 325 6 3 8.7 4.8 7500 25.2 77.4 310 5 3 10.0 5.5 | 25.8 78.4 325 6 3 9.6 5.3 7250 26.0 78.8 310 5 3 11.8 6.4 | 26.5 79.7 320 6 3 10.1 5.6 7000 26.8 80.2 310 5 3 10.9 6.0 | 27.2 81.0 320 6 3 10.1 5.5 6750 27.6 81.7 310 5 3 8.9 4.9 | 28.0 82.4 320 6 3 10.2 5.6 6500 28.3 82.9 310 5 3 10.1 5.5 | 28.8 83.8 320 6 3 10.6 5.8 6250 29.1 84.4 305 5 3 12.1 6.6 | 29.6 85.3 320 6 3 11.2 6.1 6000 30.0 86.0 305 5 3 10.4 5.7 | 30.4 86.7 320 6 3 10.4 5.7 5750 30.8 87.4 305 5 3 13.2 7.2 | 31.2 88.2 320 6 3 11.8 6.5 5500 32.1 89.8 305 5 3 25.3 13.9 | 32.3 90.1 315 6 3 17.8 9.7 ________________________________________________________________________________ This product is issued twice per day, once by approximately 0630 MST/0730 MDT (1330 UTC) and again by approximately 1830 MST/1930 MDT (0130 UTC). It is not continuously monitored nor updated after its initial issuance. The information contained herein is based on rawinsonde observation and/or numerical weather prediction model data taken near the old Stapleton Airport site in Denver, Colorado at North Latitude: 39 deg 46 min 5.016 sec West Longitude: 104 deg 52 min 9.984 sec Elevation: 5285 feet (1611 meters) and may not be representative of other areas along the Front Range of the Colorado Rocky Mountains. Note that some elevations in numerical weather prediction models differ from actual station elevations, which can lead to data which appear to be below ground. Erroneous data such as these should not be used. The content and format of this report as well as the issuance times are subject to change without prior notice. Comments and suggestions are welcome and should be directed to one of the addresses or phone numbers shown at the bottom of this page. To expedite a response to comments, be sure to mention your interest in the soaring forecast. DEFINITIONS: CAPE (Convective Available Potential Energy) - An integrated measure of the energy available for convective development, also known as the positive area on a thermodynamic diagram. Units are Joules per kilogram. Larger values are indicative of greater instability and the possibility of stronger convective activity, including thunderstorms. Values around or greater than 1000 suggest the possibility of severe weather should convective activity develop. 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