Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
605 UXUS97 KBOU 251331 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0730 MDT Tuesday, June 25, 2024 This forecast is for Tuesday, June 25, 2024: If the trigger temperature of 87.4 F/30.8 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1611 ft/min (8.2 m/s) Maximum height of thermals.................. 21830 ft MSL (16507 ft AGL) Forecast maximum temperature................... 98.0 F/37.1 C Time of trigger temperature.................... 0945 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................. 17543 ft MSL (12220 ft AGL) Thermal soaring outlook for Wednesday 06/26.... 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....................... 15883 ft MSL (10560 ft AGL) Wave soaring outlook for Wednesday 06/26....... Poor Remarks... Sunrise/Sunset.................... 05:33:00 / 20:31:39 MDT Total possible sunshine........... 14 hr 58 min 39 sec (898 min 39 sec) Altitude of sun at 13:02:19 MDT... 73.58 degrees Upper air data from numerical model forecast valid on 06/25/2024 at 0600 MDT Freezing level.................. 16239 ft MSL (10916 ft AGL) Convective condensation level... 19075 ft MSL (13752 ft AGL) Lifted condensation level....... 20123 ft MSL (14800 ft AGL) Lifted index.................... -2.1 K index......................... +18.7 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 -82.1 290 43 22 3.7 2.0 M M M M M 45000 -56.4 -69.5 285 56 29 6.4 3.5 M M M M M 40000 -46.6 -51.9 285 63 32 5.7 3.1 M M M M M 38000 -43.2 -45.8 285 62 32 5.7 3.1 M M M M M 36000 -39.8 -39.6 290 61 32 5.6 3.1 M M M M M 34000 -36.7 -34.1 290 54 28 5.0 2.7 M M M M M 32000 -33.8 -28.8 290 47 24 4.9 2.7 M M M M M 30000 -29.3 -20.7 290 41 21 6.9 3.8 46.1 114.9 7.2 M M 29000 -27.2 -17.0 290 38 20 7.0 3.8 45.1 113.1 6.5 M M 28000 -25.2 -13.4 290 35 18 6.6 3.6 44.1 111.3 5.8 M M 27000 -23.2 -9.8 290 31 16 6.7 3.7 42.8 109.0 4.8 M M 26000 -21.2 -6.2 290 27 14 6.7 3.7 41.6 106.9 3.9 M M 25000 -19.2 -2.6 295 22 12 6.6 3.6 40.6 105.1 3.1 M M 24000 -17.3 0.9 295 20 10 6.5 3.6 39.3 102.7 2.1 M M 23000 -15.4 4.3 295 18 9 6.6 3.6 38.1 100.6 1.1 M M 22000 -13.5 7.7 295 16 8 7.0 3.8 37.1 98.8 0.2 M M 21000 -11.3 11.7 295 15 8 7.5 4.1 36.2 97.1 -0.7 1535 7.8 20000 -9.1 15.6 295 15 8 7.5 4.1 35.4 95.7 -1.4 1440 7.3 19500 -8.0 17.6 295 15 8 7.5 4.1 35.1 95.1 -1.7 1392 7.1 19000 -6.9 19.6 295 14 7 8.1 4.4 34.7 94.5 -2.0 1343 6.8 18500 -5.7 21.7 295 13 7 8.0 4.4 34.4 94.0 -2.4 1294 6.6 18000 -4.5 23.9 295 12 6 8.0 4.4 34.2 93.5 -2.6 1244 6.3 17500 -3.4 25.9 295 11 5 8.0 4.4 33.8 92.9 -3.0 1194 6.1 17000 -2.2 28.0 295 9 5 7.9 4.3 33.6 92.4 -3.3 1144 5.8 16500 -1.0 30.2 300 8 4 8.7 4.8 33.3 92.0 -3.5 1093 5.6 16000 0.9 33.6 310 6 3 8.6 4.7 33.0 91.5 -3.8 1014 5.1 15500 2.2 36.0 320 6 3 8.9 4.9 32.9 91.2 -4.0 960 4.9 15000 3.5 38.3 330 6 3 8.8 4.8 32.7 90.9 -4.2 906 4.6 14500 4.8 40.6 340 6 3 9.0 5.0 32.6 90.6 -4.4 852 4.3 14000 6.2 43.2 345 7 4 9.1 5.0 32.5 90.4 -4.5 797 4.1 13500 7.5 45.5 350 7 4 9.2 5.0 32.4 90.3 -4.6 742 3.8 13000 8.9 48.0 350 8 4 9.3 5.1 32.3 90.1 -4.7 686 3.5 12500 10.3 50.5 350 8 4 9.3 5.1 32.2 90.0 -4.8 630 3.2 12000 11.6 52.9 350 9 4 9.3 5.1 32.1 89.9 -4.9 574 2.9 11500 13.0 55.4 350 9 5 9.2 5.1 32.1 89.7 -5.0 518 2.6 11000 14.4 57.9 345 9 5 8.8 4.8 32.0 89.6 -5.1 462 2.3 10500 15.8 60.4 345 9 5 4.8 2.6 31.9 89.4 -5.3 406 2.1 10250 16.0 60.8 350 8 4 6.0 3.3 31.3 88.4 -5.8 393 2.0 10000 16.8 62.2 345 8 4 12.2 6.7 31.4 88.6 -5.7 361 1.8 9750 17.6 63.7 340 9 4 11.0 6.0 31.5 88.7 -5.7 329 1.7 9500 18.4 65.1 340 9 5 9.5 5.2 31.6 88.9 -5.6 297 1.5 9250 19.0 66.2 340 9 5 7.4 4.0 31.5 88.7 -5.7 273 1.4 9000 19.6 67.3 340 9 5 9.3 5.1 31.4 88.4 -5.9 247 1.3 8750 20.4 68.7 335 10 5 10.6 5.8 31.4 88.5 -5.9 217 1.1 8500 21.1 70.0 330 10 5 9.4 5.2 31.4 88.6 -5.8 187 0.9 8250 21.7 71.1 330 11 6 7.9 4.3 31.3 88.4 -5.9 161 0.8 8000 22.3 72.1 330 11 6 7.8 4.3 31.2 88.1 -6.1 136 0.7 7750 22.9 73.2 320 12 6 8.7 4.8 31.1 87.9 -6.3 111 0.6 7500 23.5 74.3 315 13 7 6.8 3.8 31.0 87.7 -6.4 85 0.4 7250 23.9 75.0 315 14 7 4.8 2.7 30.6 87.1 -6.8 66 0.3 7000 24.3 75.7 310 15 8 4.9 2.7 30.3 86.5 -7.1 48 0.2 6750 24.6 76.3 305 15 8 4.3 2.4 29.9 85.7 -7.6 32 0.2 6500 24.7 76.5 295 15 8 -1.4 -0.8 29.3 84.7 -8.2 21 0.1 6250 24.3 75.7 290 13 7 -6.1 -3.4 28.2 82.7 -9.4 25 0.1 6000 23.9 75.0 285 12 6 -3.3 -1.8 27.1 80.8 -10.5 30 0.2 5750 23.4 74.1 275 11 6 -11.0 -6.1 26.0 78.7 -11.7 36 0.2 5500 21.8 71.2 250 7 4 -30.8 -16.9 23.7 74.6 -14.1 77 0.4 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/25/2024 at 0900 MDT | 06/25/2024 at 1200 MDT | CAPE... +6.2 LI... +0.6 | CAPE... +32.7 LI... -0.3 CINH... -28.9 K Index... +18.3 | CINH... -3.4 K Index... +17.5 | 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 -62.9 -81.2 285 39 20 3.0 1.7 | -62.9 -81.2 285 34 18 3.2 1.8 45000 -56.3 -69.3 285 55 28 6.2 3.4 | -56.2 -69.2 290 51 26 6.0 3.3 40000 -47.1 -52.8 290 61 31 5.8 3.2 | -47.1 -52.8 290 60 31 6.1 3.4 38000 -43.7 -46.7 290 59 31 5.8 3.2 | -43.4 -46.1 290 60 31 6.1 3.4 36000 -40.2 -40.4 290 57 30 5.7 3.1 | -39.8 -39.6 290 60 31 5.9 3.3 34000 -37.0 -34.6 295 52 27 5.2 2.9 | -36.7 -34.1 290 53 27 5.1 2.8 32000 -33.9 -29.0 295 46 24 5.1 2.8 | -33.2 -27.8 290 45 23 5.9 3.2 30000 -29.1 -20.4 300 41 21 7.5 4.1 | -29.0 -20.2 290 42 22 7.2 4.0 29000 -26.8 -16.2 300 39 20 7.5 4.1 | -26.8 -16.2 290 41 21 7.3 4.0 28000 -24.6 -12.3 300 37 19 6.7 3.7 | -24.6 -12.3 290 40 20 7.4 4.1 27000 -22.6 -8.7 295 34 17 6.8 3.7 | -22.4 -8.3 290 38 19 7.4 4.1 26000 -20.6 -5.1 295 31 16 6.8 3.7 | -20.2 -4.4 290 36 18 7.4 4.1 25000 -18.5 -1.3 290 28 14 6.5 3.6 | -17.9 -0.2 295 34 17 6.5 3.6 24000 -16.7 1.9 290 25 13 6.0 3.3 | -16.4 2.5 290 31 16 5.2 2.9 23000 -15.0 5.0 290 21 11 6.0 3.3 | -14.8 5.4 285 27 14 5.3 2.9 22000 -13.2 8.2 290 18 9 6.4 3.5 | -13.3 8.1 280 24 13 5.9 3.2 21000 -11.2 11.8 295 17 9 6.8 3.7 | -11.4 11.5 285 23 12 6.5 3.6 20000 -9.3 15.3 300 16 8 6.9 3.8 | -9.5 14.9 285 21 11 6.6 3.6 19500 -8.3 17.1 305 15 8 6.8 3.8 | -8.6 16.5 290 20 10 6.7 3.7 19000 -7.2 19.0 305 15 8 8.2 4.5 | -7.5 18.5 290 20 10 8.4 4.6 18500 -6.1 21.0 305 14 7 8.1 4.4 | -6.3 20.7 295 19 10 8.3 4.5 18000 -4.9 23.2 305 13 7 8.3 4.6 | -5.1 22.8 295 18 10 8.7 4.8 17500 -3.6 25.5 305 13 7 8.5 4.7 | -3.8 25.2 300 18 9 8.9 4.9 17000 -2.4 27.7 305 12 6 8.5 4.7 | -1.8 28.8 305 18 9 9.1 5.0 16500 -0.5 31.1 300 11 6 8.6 4.7 | -0.4 31.3 305 17 9 9.2 5.0 16000 0.7 33.3 300 10 5 8.6 4.7 | 0.9 33.6 305 17 9 9.2 5.1 15500 2.0 35.6 300 9 5 9.0 4.9 | 2.3 36.1 310 16 8 9.6 5.3 15000 3.4 38.1 300 8 4 8.9 4.9 | 3.8 38.8 310 15 8 9.6 5.2 14500 4.7 40.5 300 8 4 9.2 5.0 | 5.2 41.4 310 15 8 9.5 5.2 14000 6.1 43.0 305 8 4 9.2 5.0 | 6.6 43.9 310 14 7 9.5 5.2 13500 7.4 45.3 305 7 4 9.2 5.1 | 8.0 46.4 310 14 7 9.5 5.2 13000 8.8 47.8 305 7 4 9.3 5.1 | 9.4 48.9 310 13 7 9.6 5.2 12500 10.2 50.4 305 7 4 9.3 5.1 | 10.8 51.4 310 13 7 9.5 5.2 12000 11.6 52.9 300 7 4 9.3 5.1 | 12.2 54.0 310 12 6 9.5 5.2 11500 13.0 55.4 300 7 4 9.2 5.1 | 13.6 56.5 310 11 6 9.5 5.2 11000 14.3 57.7 300 7 4 8.8 4.8 | 15.0 59.0 310 10 5 9.1 5.0 10500 15.7 60.3 305 7 4 4.4 2.4 | 16.4 61.5 310 8 4 4.7 2.6 10250 15.9 60.6 300 6 3 5.7 3.2 | 16.6 61.9 315 7 4 6.4 3.5 10000 16.7 62.1 305 6 3 12.5 6.8 | 17.5 63.5 315 7 4 13.2 7.3 9750 17.5 63.5 310 7 3 11.3 6.2 | 18.3 64.9 315 6 3 12.2 6.7 9500 18.3 64.9 310 7 4 9.2 5.1 | 19.2 66.6 315 6 3 9.4 5.2 9250 18.9 66.0 315 7 3 6.9 3.8 | 19.8 67.6 320 5 3 7.7 4.2 9000 19.5 67.1 315 7 3 9.4 5.2 | 20.5 68.9 320 5 3 11.0 6.0 8750 20.2 68.4 315 7 4 10.8 5.9 | 21.3 70.3 320 5 3 11.8 6.5 8500 21.0 69.8 315 8 4 8.9 4.9 | 22.2 72.0 320 5 2 9.9 5.4 8250 21.5 70.7 315 8 4 6.3 3.5 | 22.8 73.0 325 4 2 7.3 4.0 8000 22.0 71.6 315 8 4 7.5 4.1 | 23.4 74.1 330 4 2 10.0 5.5 7750 22.7 72.9 315 9 4 9.6 5.3 | 24.3 75.7 325 4 2 12.4 6.8 7500 23.3 73.9 315 9 5 6.5 3.6 | 25.1 77.2 325 4 2 9.7 5.3 7250 23.6 74.5 315 9 5 3.6 2.0 | 25.8 78.4 330 4 2 7.4 4.1 7000 23.9 75.0 315 9 5 5.2 2.8 | 26.4 79.5 340 3 2 9.7 5.3 6750 24.3 75.7 315 9 5 7.1 3.9 | 27.2 81.0 335 3 2 13.0 7.1 6500 24.8 76.6 310 8 4 6.6 3.6 | 28.2 82.8 335 3 2 11.3 6.2 6250 25.2 77.4 310 7 4 5.8 3.2 | 28.9 84.0 340 3 1 9.9 5.4 6000 25.6 78.1 305 5 3 5.4 2.9 | 29.7 85.5 350 3 1 9.2 5.1 5750 26.1 79.0 300 4 2 10.4 5.7 | 30.5 86.9 350 3 1 15.2 8.3 5500 27.3 81.1 295 3 2 21.6 11.8 | 32.1 89.8 350 2 1 29.9 16.4 06/25/2024 at 1500 MDT | 06/25/2024 at 1800 MDT | CAPE... +71.7 LI... -0.7 | CAPE... +89.9 LI... -0.0 CINH... -12.1 K Index... +20.3 | CINH... -49.1 K Index... +24.5 | 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 -62.8 -81.0 285 30 15 4.2 2.3 | -62.6 -80.7 285 28 15 4.7 2.6 45000 -55.5 -67.9 290 45 23 5.3 2.9 | -55.4 -67.7 290 43 22 5.0 2.8 40000 -47.2 -53.0 290 61 32 6.4 3.5 | -47.3 -53.1 295 61 31 6.8 3.7 38000 -43.3 -45.9 290 63 32 6.4 3.5 | -43.3 -45.9 295 63 33 6.8 3.7 36000 -39.5 -39.1 295 64 33 6.2 3.4 | -39.2 -38.6 295 65 34 6.4 3.5 34000 -36.3 -33.3 295 58 30 5.2 2.8 | -35.7 -32.3 295 58 30 5.0 2.8 32000 -32.8 -27.0 295 50 26 5.6 3.1 | -32.7 -26.9 290 50 26 5.7 3.1 30000 -29.2 -20.6 290 46 24 6.1 3.3 | -28.9 -20.0 290 45 23 6.4 3.5 29000 -27.4 -17.3 285 44 23 6.2 3.4 | -27.0 -16.6 285 43 22 6.4 3.5 28000 -25.5 -13.9 285 43 22 7.6 4.2 | -25.1 -13.2 285 40 21 6.4 3.5 27000 -23.3 -9.9 285 40 20 7.5 4.1 | -23.2 -9.8 280 38 19 6.5 3.5 26000 -21.1 -6.0 285 37 19 7.5 4.1 | -21.4 -6.5 280 35 18 6.5 3.6 25000 -18.8 -1.8 285 34 18 6.8 3.7 | -19.5 -3.1 280 33 17 7.2 3.9 24000 -17.0 1.4 285 31 16 6.1 3.3 | -17.2 1.0 280 31 16 7.8 4.3 23000 -15.2 4.6 285 28 15 6.1 3.3 | -14.9 5.2 280 29 15 7.8 4.3 22000 -13.4 7.9 290 25 13 6.9 3.8 | -12.6 9.3 280 27 14 7.6 4.2 21000 -11.3 11.7 290 23 12 7.5 4.1 | -10.4 13.3 285 25 13 7.4 4.1 20000 -9.1 15.6 290 22 11 7.6 4.1 | -8.2 17.2 290 23 12 7.5 4.1 19500 -8.0 17.6 295 21 11 7.7 4.3 | -7.1 19.2 295 22 11 7.5 4.1 19000 -6.7 19.9 295 20 10 9.3 5.1 | -5.9 21.4 295 20 10 8.5 4.6 18500 -5.4 22.3 295 19 10 9.2 5.0 | -4.7 23.5 295 19 10 8.4 4.6 18000 -4.0 24.8 295 19 10 9.4 5.2 | -2.8 27.0 300 17 9 8.7 4.8 17500 -2.6 27.3 295 18 9 9.5 5.2 | -1.6 29.1 300 16 8 8.7 4.8 17000 -0.5 31.1 300 16 8 9.5 5.2 | -0.3 31.5 300 15 8 9.0 4.9 16500 0.9 33.6 300 16 8 9.5 5.2 | 1.1 34.0 305 14 7 9.1 5.0 16000 2.3 36.1 300 15 8 9.5 5.2 | 2.4 36.3 305 13 7 9.1 5.0 15500 3.7 38.7 300 14 7 9.6 5.3 | 3.7 38.7 310 12 6 9.2 5.0 15000 5.2 41.4 305 14 7 9.6 5.3 | 5.1 41.2 315 11 5 9.2 5.0 14500 6.6 43.9 305 13 7 9.5 5.2 | 6.5 43.7 320 9 5 9.2 5.0 14000 8.0 46.4 305 12 6 9.5 5.2 | 7.9 46.2 325 8 4 9.2 5.0 13500 9.4 48.9 305 11 6 9.5 5.2 | 9.2 48.6 330 7 4 9.2 5.0 13000 10.8 51.4 310 11 5 9.5 5.2 | 10.6 51.1 335 7 4 9.2 5.1 12500 12.2 54.0 310 10 5 9.5 5.2 | 12.0 53.6 340 6 3 9.4 5.1 12000 13.6 56.5 315 9 5 9.5 5.2 | 13.4 56.1 345 6 3 9.5 5.2 11500 15.1 59.2 315 9 4 9.6 5.3 | 14.8 58.6 350 5 3 9.5 5.2 11000 16.5 61.7 315 8 4 9.4 5.1 | 16.3 61.3 350 5 3 9.3 5.1 10500 18.0 64.4 320 8 4 5.1 2.8 | 17.7 63.9 355 5 3 5.8 3.2 10250 18.2 64.8 320 8 4 6.5 3.6 | 18.0 64.4 355 5 3 7.0 3.8 10000 19.1 66.4 320 8 4 13.2 7.2 | 18.8 65.8 355 5 3 12.4 6.8 9750 20.0 68.0 320 8 4 12.3 6.7 | 19.7 67.5 355 5 2 11.6 6.4 9500 20.8 69.4 320 7 4 9.2 5.1 | 20.5 68.9 360 5 2 9.3 5.1 9250 21.4 70.5 320 8 4 7.7 4.2 | 21.1 70.0 360 5 2 7.7 4.2 9000 22.1 71.8 325 7 4 11.1 6.1 | 21.8 71.2 360 5 2 10.3 5.7 8750 23.0 73.4 325 7 4 11.6 6.4 | 22.6 72.7 360 4 2 10.9 6.0 8500 23.8 74.8 325 7 3 9.9 5.4 | 23.4 74.1 360 4 2 9.5 5.2 8250 24.4 75.9 325 7 4 7.6 4.2 | 24.0 75.2 360 4 2 7.5 4.1 8000 25.1 77.2 325 7 4 10.1 5.5 | 24.6 76.3 355 4 2 9.3 5.1 7750 25.9 78.6 325 7 3 12.5 6.9 | 25.4 77.7 355 3 2 11.4 6.2 7500 26.8 80.2 325 6 3 9.5 5.2 | 26.2 79.2 360 3 1 9.3 5.1 7250 27.4 81.3 330 6 3 6.7 3.6 | 26.8 80.2 350 3 1 7.2 4.0 7000 27.9 82.2 330 7 3 9.5 5.2 | 27.4 81.3 345 3 1 9.0 4.9 6750 28.8 83.8 330 6 3 13.5 7.4 | 28.1 82.6 335 3 1 11.6 6.4 6500 29.8 85.6 330 6 3 11.5 6.3 | 29.0 84.2 325 2 1 10.0 5.5 6250 30.5 86.9 330 6 3 9.6 5.3 | 29.6 85.3 315 2 1 8.2 4.5 6000 31.3 88.3 330 6 3 9.2 5.0 | 30.2 86.4 305 3 1 8.3 4.5 5750 32.1 89.8 330 6 3 14.7 8.0 | 30.8 87.4 295 3 2 9.1 5.0 5500 33.7 92.7 330 5 3 28.8 15.8 | 31.6 88.9 285 3 2 12.9 7.1 ________________________________________________________________________________ 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