Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
157 UXUS97 KBOU 051333 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0733 MDT Wednesday, June 5, 2024 This forecast is for Wednesday, June 5, 2024: If the trigger temperature of 76.8 F/24.9 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 977 ft/min (5.0 m/s) Maximum height of thermals.................. 17126 ft MSL (11822 ft AGL) Forecast maximum temperature................... 92.0 F/33.8 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................. 14061 ft MSL (8757 ft AGL) Thermal soaring outlook for Thursday 06/06..... Excellent Wave Soaring Index............................. Poor Wave Soaring Index trend (to 1800 MDT)......... No cahnge Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1800 MDT)................ Neither Potential height of wave....................... 36032 ft MSL (30728 ft AGL) Wave soaring outlook for Thursday 06/06........ Poor Remarks... Sunrise/Sunset.................... 05:31:48 / 20:24:30 MDT Total possible sunshine........... 14 hr 52 min 42 sec (892 min 42 sec) Altitude of sun at 12:58:09 MDT... 72.89 degrees Upper air data from numerical model forecast valid on 06/05/2024 at 0600 MDT Freezing level.................. 15891 ft MSL (10587 ft AGL) Convective condensation level... 19389 ft MSL (14085 ft AGL) Lifted condensation level....... 18659 ft MSL (13355 ft AGL) Lifted index.................... +1.8 K index......................... -2.5 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 -62.5 -80.5 340 17 9 1.2 0.7 M M M M M 45000 -58.7 -73.7 320 28 15 4.8 2.6 M M M M M 40000 -51.3 -60.3 335 38 19 6.2 3.4 M M M M M 38000 -47.5 -53.5 330 42 21 6.3 3.4 M M M M M 36000 -43.8 -46.8 330 46 24 6.1 3.3 M M M M M 34000 -39.1 -38.4 330 42 22 8.0 4.4 M M M M M 32000 -34.3 -29.7 325 36 19 8.0 4.4 M M M M M 30000 -28.8 -19.8 320 34 17 8.2 4.5 47.2 116.9 10.6 M M 29000 -26.4 -15.5 320 33 17 8.2 4.5 46.6 115.9 10.2 M M 28000 -23.9 -11.0 315 32 17 7.7 4.2 46.1 115.0 10.0 M M 27000 -21.7 -7.1 315 32 17 7.6 4.2 45.2 113.3 9.3 M M 26000 -19.4 -2.9 315 32 17 7.6 4.2 44.3 111.8 8.7 M M 25000 -17.2 1.0 315 33 17 7.6 4.2 43.6 110.6 8.3 M M 24000 -15.3 4.5 315 33 17 6.0 3.3 42.3 108.2 7.3 M M 23000 -13.4 7.9 315 34 17 6.1 3.3 41.0 105.7 6.2 M M 22000 -11.6 11.1 315 34 18 6.1 3.3 39.7 103.5 5.3 M M 21000 -9.8 14.4 315 34 17 6.0 3.3 38.3 101.0 4.2 M M 20000 -8.0 17.6 320 33 17 6.0 3.3 37.0 98.6 3.1 M M 19500 -7.1 19.2 320 32 17 6.0 3.3 36.4 97.5 2.5 M M 19000 -6.2 20.8 320 31 16 6.2 3.4 35.8 96.5 2.0 M M 18500 -5.3 22.5 320 30 16 6.2 3.4 35.2 95.4 1.5 M M 18000 -4.4 24.1 320 29 15 6.3 3.4 34.6 94.3 1.0 M M 17500 -3.4 25.9 320 28 14 6.5 3.6 34.0 93.2 0.5 M M 17000 -2.5 27.5 325 26 14 6.5 3.6 33.5 92.2 -0.0 975 5.0 16500 -1.5 29.3 325 25 13 6.8 3.7 32.9 91.3 -0.5 931 4.7 16000 -0.5 31.1 325 24 12 6.9 3.8 32.4 90.4 -1.0 886 4.5 15500 1.0 33.8 320 22 11 6.7 3.7 31.7 89.1 -1.6 818 4.2 15000 2.0 35.6 320 21 11 6.7 3.7 31.2 88.2 -2.1 774 3.9 14500 3.0 37.4 320 20 10 6.5 3.6 30.7 87.3 -2.6 730 3.7 14000 3.9 39.0 315 20 10 6.3 3.5 30.1 86.2 -3.2 688 3.5 13500 4.8 40.6 315 19 10 6.3 3.5 29.6 85.3 -3.7 646 3.3 13000 5.7 42.3 315 19 10 6.2 3.4 29.0 84.2 -4.3 604 3.1 12500 6.6 43.9 315 19 10 6.3 3.4 28.4 83.2 -5.0 563 2.9 12000 7.5 45.5 315 19 10 6.9 3.8 27.9 82.3 -5.5 520 2.6 11500 8.5 47.3 310 19 10 6.9 3.8 27.5 81.5 -6.0 476 2.4 11000 9.5 49.1 310 19 10 7.2 4.0 27.1 80.7 -6.5 431 2.2 10500 10.6 51.1 310 19 10 5.3 2.9 26.7 80.0 -6.9 384 2.0 10250 10.9 51.6 310 20 10 3.7 2.0 26.2 79.2 -7.4 369 1.9 10000 11.3 52.3 305 20 10 7.6 4.2 25.9 78.6 -7.7 349 1.8 9750 11.9 53.4 305 20 11 9.2 5.0 25.8 78.4 -7.8 323 1.6 9500 12.5 54.5 305 21 11 8.8 4.8 25.7 78.3 -8.0 296 1.5 9250 13.1 55.6 300 22 11 5.0 2.7 25.6 78.0 -8.2 273 1.4 9000 13.4 56.1 300 23 12 5.3 2.9 25.1 77.2 -8.6 257 1.3 8750 13.9 57.0 300 23 12 8.6 4.7 24.9 76.9 -8.8 233 1.2 8500 14.5 58.1 300 23 12 7.2 4.0 24.8 76.6 -9.0 209 1.1 8250 14.9 58.8 295 23 12 4.5 2.5 24.5 76.1 -9.4 189 1.0 8000 15.2 59.4 295 24 12 4.5 2.5 24.1 75.3 -9.8 174 0.9 7750 15.6 60.1 295 23 12 7.3 4.0 23.8 74.8 -10.2 153 0.8 7500 16.1 61.0 295 21 11 6.5 3.6 23.6 74.5 -10.4 130 0.7 7250 16.5 61.7 290 20 10 4.9 2.7 23.3 73.9 -10.8 111 0.6 7000 16.9 62.4 290 18 9 4.8 2.7 22.9 73.2 -11.2 93 0.5 6750 17.3 63.1 290 16 8 7.8 4.3 22.6 72.7 -11.5 73 0.4 6500 17.8 64.0 285 13 7 5.3 2.9 22.5 72.4 -11.7 49 0.2 6250 18.0 64.4 280 10 5 0.6 0.3 21.9 71.4 -12.3 37 0.2 6000 18.1 64.6 275 8 4 3.8 2.1 21.3 70.3 -12.9 26 0.1 5750 18.2 64.8 260 6 3 -4.2 -2.3 20.7 69.3 -13.6 15 0.1 5500 17.1 62.8 230 5 3 -27.3 -15.0 18.8 65.9 -15.5 43 0.2 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/05/2024 at 0900 MDT | 06/05/2024 at 1200 MDT | CAPE... 0.0 LI... +6.1 | CAPE... 0.0 LI... +5.1 CINH... -1.2 K Index... -3.2 | CINH... -0.0 K Index... -0.9 | 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 -62.2 -80.0 330 9 5 0.7 0.4 | -62.4 -80.3 285 8 4 1.4 0.8 45000 -58.9 -74.0 315 25 13 5.0 2.7 | -58.5 -73.3 315 22 11 4.9 2.7 40000 -51.2 -60.2 320 38 20 6.2 3.4 | -50.8 -59.4 325 40 20 6.4 3.5 38000 -47.5 -53.5 320 42 22 6.2 3.4 | -46.9 -52.4 320 44 22 6.4 3.5 36000 -43.8 -46.8 325 46 24 6.1 3.3 | -43.1 -45.6 320 47 24 6.4 3.5 34000 -39.2 -38.6 320 44 22 7.9 4.4 | -38.2 -36.8 315 45 23 7.3 4.0 32000 -33.8 -28.8 315 40 21 8.2 4.5 | -33.9 -29.0 310 43 22 7.5 4.1 30000 -29.0 -20.2 315 38 20 8.1 4.4 | -29.3 -20.7 305 40 20 7.6 4.2 29000 -26.6 -15.9 320 37 19 8.1 4.4 | -27.1 -16.8 305 38 20 7.6 4.2 28000 -24.2 -11.6 320 36 19 7.3 4.0 | -24.8 -12.6 305 37 19 7.4 4.0 27000 -22.0 -7.6 320 36 18 7.1 3.9 | -22.6 -8.7 305 36 18 7.3 4.0 26000 -19.9 -3.8 320 35 18 7.1 3.9 | -20.4 -4.7 305 35 18 7.3 4.0 25000 -17.8 -0.0 320 35 18 7.1 3.9 | -18.2 -0.8 305 34 17 7.3 4.0 24000 -15.8 3.6 315 34 18 6.7 3.7 | -16.0 3.2 305 33 17 7.4 4.1 23000 -13.7 7.3 315 34 17 6.7 3.7 | -13.8 7.2 305 33 17 7.4 4.1 22000 -11.7 10.9 315 33 17 6.7 3.7 | -11.6 11.1 305 33 17 7.4 4.0 21000 -9.7 14.5 315 32 16 6.6 3.6 | -9.4 15.1 310 31 16 7.1 3.9 20000 -7.8 18.0 315 30 15 6.6 3.6 | -7.3 18.9 310 30 16 7.1 3.9 19500 -6.8 19.8 315 29 15 6.6 3.6 | -6.2 20.8 310 29 15 7.1 3.9 19000 -5.8 21.6 315 28 15 6.2 3.4 | -5.2 22.6 310 29 15 6.1 3.4 18500 -4.9 23.2 320 27 14 6.1 3.4 | -4.3 24.3 310 28 14 6.0 3.3 18000 -4.0 24.8 320 26 13 6.2 3.4 | -3.4 25.9 310 27 14 5.9 3.3 17500 -3.1 26.4 320 25 13 6.4 3.5 | -2.6 27.3 310 26 13 5.6 3.1 17000 -2.1 28.2 320 24 12 6.4 3.5 | -1.3 29.7 315 24 12 5.7 3.1 16500 -1.2 29.8 325 23 12 6.7 3.7 | -0.5 31.1 315 23 12 6.0 3.3 16000 0.3 32.5 325 22 11 6.8 3.8 | 0.4 32.7 315 22 11 6.0 3.3 15500 1.3 34.3 325 21 11 6.9 3.8 | 1.3 34.3 315 20 10 6.2 3.4 15000 2.3 36.1 320 20 10 6.9 3.8 | 2.2 36.0 310 19 10 6.2 3.4 14500 3.3 37.9 320 20 10 6.6 3.6 | 3.1 37.6 310 18 9 5.6 3.1 14000 4.3 39.7 315 19 10 6.4 3.5 | 3.8 38.8 305 18 9 5.4 3.0 13500 5.2 41.4 315 19 10 6.2 3.4 | 4.6 40.3 305 17 9 6.0 3.3 13000 6.0 42.8 310 19 10 5.9 3.2 | 5.5 41.9 305 16 8 7.1 3.9 12500 6.9 44.4 305 19 10 5.9 3.2 | 6.5 43.7 300 16 8 7.4 4.1 12000 7.7 45.9 300 19 10 5.9 3.2 | 7.7 45.9 300 15 8 8.6 4.7 11500 8.5 47.3 300 18 9 6.0 3.3 | 9.0 48.2 305 15 8 8.6 4.7 11000 9.4 48.9 295 18 9 6.4 3.5 | 10.3 50.5 305 15 8 8.7 4.8 10500 10.4 50.7 295 17 9 4.2 2.3 | 11.7 53.1 305 15 8 3.8 2.1 10250 10.6 51.1 295 17 9 3.9 2.2 | 11.8 53.2 305 15 8 4.7 2.6 10000 11.1 52.0 295 16 8 8.2 4.5 | 12.5 54.5 305 15 8 11.8 6.5 9750 11.7 53.1 295 16 8 8.9 4.9 | 13.3 55.9 305 15 8 10.3 5.7 9500 12.3 54.1 300 16 8 8.0 4.4 | 14.0 57.2 300 15 8 9.5 5.2 9250 12.8 55.0 300 16 8 4.1 2.2 | 14.6 58.3 300 15 8 6.4 3.5 9000 13.0 55.4 300 15 8 5.6 3.1 | 15.0 59.0 305 14 7 8.7 4.8 8750 13.6 56.5 300 16 8 9.3 5.1 | 15.8 60.4 305 14 7 11.4 6.3 8500 14.2 57.6 300 16 8 7.3 4.0 | 16.6 61.9 305 14 7 9.8 5.4 8250 14.6 58.3 295 16 8 4.4 2.4 | 17.2 63.0 305 13 7 7.1 3.9 8000 14.9 58.8 295 15 8 5.1 2.8 | 17.8 64.0 305 12 6 9.0 4.9 7750 15.4 59.7 290 14 7 8.3 4.6 | 18.6 65.5 305 13 6 13.1 7.2 7500 16.0 60.8 290 14 7 7.6 4.2 | 19.5 67.1 305 13 7 10.2 5.6 7250 16.5 61.7 285 12 6 6.2 3.4 | 20.1 68.2 305 13 6 6.6 3.6 7000 17.0 62.6 285 11 5 7.1 3.9 | 20.7 69.3 310 12 6 8.5 4.7 6750 17.6 63.7 280 9 5 11.7 6.4 | 21.5 70.7 310 12 6 13.7 7.5 6500 18.6 65.5 275 9 4 11.3 6.2 | 22.5 72.5 305 12 6 12.2 6.7 6250 19.2 66.6 275 8 4 8.6 4.7 | 23.3 73.9 310 12 6 9.1 5.0 6000 19.9 67.8 270 7 4 8.8 4.8 | 24.0 75.2 310 11 6 9.0 4.9 5750 20.6 69.1 270 7 3 12.6 6.9 | 24.8 76.6 310 11 5 15.1 8.3 5500 21.9 71.4 265 6 3 21.4 11.7 | 26.4 79.5 310 10 5 30.0 16.4 06/05/2024 at 1500 MDT | 06/05/2024 at 1800 MDT | CAPE... 0.0 LI... +4.0 | CAPE... +0.2 LI... +2.9 CINH... 0.0 K Index... +8.4 | CINH... -1.7 K Index... +11.8 | 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 -62.5 -80.5 260 9 5 0.9 0.5 | -62.5 -80.5 255 16 8 0.9 0.5 45000 -58.9 -74.0 300 21 11 5.2 2.9 | -59.0 -74.2 285 28 14 5.3 2.9 40000 -50.8 -59.4 315 41 21 6.6 3.6 | -50.7 -59.3 310 43 22 6.6 3.6 38000 -46.8 -52.2 315 43 22 6.7 3.7 | -46.8 -52.2 310 45 23 6.6 3.6 36000 -42.8 -45.0 315 46 24 6.6 3.6 | -42.8 -45.0 310 48 24 6.6 3.6 34000 -38.2 -36.8 310 42 22 6.8 3.8 | -38.3 -36.9 305 43 22 6.7 3.7 32000 -34.1 -29.4 305 39 20 7.1 3.9 | -34.3 -29.7 300 39 20 7.1 3.9 30000 -29.4 -20.9 300 39 20 7.9 4.3 | -29.7 -21.5 305 38 20 7.7 4.2 29000 -27.1 -16.8 300 39 20 7.9 4.3 | -27.4 -17.3 305 38 19 7.7 4.2 28000 -24.8 -12.6 300 39 20 7.5 4.1 | -25.1 -13.2 305 38 19 7.6 4.2 27000 -22.6 -8.7 300 38 20 7.4 4.1 | -22.8 -9.0 305 37 19 7.6 4.2 26000 -20.4 -4.7 305 37 19 7.4 4.1 | -20.6 -5.1 305 37 19 7.6 4.2 25000 -18.1 -0.6 305 36 19 7.5 4.1 | -18.3 -0.9 305 37 19 7.7 4.2 24000 -15.9 3.4 305 36 18 7.7 4.2 | -16.0 3.2 305 35 18 7.7 4.2 23000 -13.6 7.5 305 35 18 7.7 4.2 | -13.7 7.3 305 34 17 7.7 4.2 22000 -11.2 11.8 305 34 18 7.5 4.1 | -11.4 11.5 305 32 16 7.5 4.1 21000 -9.1 15.6 310 33 17 7.0 3.9 | -9.2 15.4 305 30 15 7.1 3.9 20000 -7.0 19.4 310 31 16 7.1 3.9 | -7.1 19.2 305 28 14 7.1 3.9 19500 -5.9 21.4 310 30 16 7.1 3.9 | -6.0 21.2 305 27 14 7.1 3.9 19000 -4.9 23.2 310 29 15 6.4 3.5 | -5.0 23.0 300 26 13 6.7 3.7 18500 -3.9 25.0 305 28 14 6.4 3.5 | -4.0 24.8 300 24 13 6.7 3.7 18000 -3.0 26.6 305 27 14 6.3 3.4 | -3.0 26.6 295 23 12 6.6 3.6 17500 -1.6 29.1 300 25 13 5.9 3.3 | -2.1 28.2 295 22 12 6.5 3.6 17000 -0.8 30.6 300 24 12 6.0 3.3 | -0.6 30.9 290 21 11 6.7 3.7 16500 0.1 32.2 295 23 12 6.0 3.3 | 0.4 32.7 290 20 10 7.1 3.9 16000 1.0 33.8 295 22 12 6.0 3.3 | 1.5 34.7 290 19 10 7.1 3.9 15500 1.9 35.4 295 22 11 6.9 3.8 | 2.5 36.5 290 19 10 7.7 4.2 15000 2.9 37.2 295 22 11 6.9 3.8 | 3.6 38.5 290 19 10 7.6 4.2 14500 3.9 39.0 295 21 11 7.8 4.3 | 4.8 40.6 290 19 10 8.1 4.5 14000 5.1 41.2 295 21 11 8.2 4.5 | 6.0 42.8 290 19 10 8.3 4.5 13500 6.3 43.3 295 20 11 8.3 4.5 | 7.2 45.0 290 19 10 8.3 4.6 13000 7.5 45.5 295 20 10 8.4 4.6 | 8.4 47.1 295 19 10 8.3 4.6 12500 8.7 47.7 295 20 10 8.4 4.6 | 9.6 49.3 295 20 10 8.4 4.6 12000 9.9 49.8 295 19 10 8.4 4.6 | 10.9 51.6 295 19 10 8.6 4.7 11500 11.1 52.0 295 17 9 8.5 4.6 | 12.1 53.8 300 19 10 8.7 4.7 11000 12.4 54.3 295 16 8 9.0 4.9 | 13.4 56.1 300 19 10 8.5 4.7 10500 13.8 56.8 295 15 8 4.8 2.6 | 14.7 58.5 305 19 10 4.1 2.2 10250 14.0 57.2 300 15 8 6.2 3.4 | 14.8 58.6 305 19 10 5.5 3.0 10000 14.9 58.8 300 15 8 12.9 7.1 | 15.6 60.1 305 19 10 12.5 6.9 9750 15.7 60.3 300 15 8 11.4 6.3 | 16.5 61.7 305 19 10 11.2 6.1 9500 16.6 61.9 300 15 8 10.6 5.8 | 17.3 63.1 305 19 10 9.6 5.3 9250 17.2 63.0 300 15 8 8.1 4.4 | 17.9 64.2 305 19 10 6.9 3.8 9000 17.9 64.2 300 15 8 9.5 5.2 | 18.4 65.1 310 19 10 9.6 5.3 8750 18.7 65.7 300 15 8 11.1 6.1 | 19.3 66.7 310 19 10 11.7 6.4 8500 19.5 67.1 305 15 8 10.2 5.6 | 20.1 68.2 310 19 10 10.2 5.6 8250 20.2 68.4 305 15 8 8.2 4.5 | 20.7 69.3 310 20 10 6.8 3.7 8000 20.8 69.4 305 15 8 9.4 5.2 | 21.3 70.3 310 20 10 8.9 4.9 7750 21.6 70.9 305 15 8 11.9 6.5 | 22.1 71.8 310 20 10 12.8 7.0 7500 22.4 72.3 305 15 8 10.1 5.5 | 23.0 73.4 310 20 10 10.0 5.5 7250 23.1 73.6 305 15 8 7.9 4.3 | 23.6 74.5 310 20 10 6.9 3.8 7000 23.7 74.7 310 15 8 8.8 4.8 | 24.1 75.4 315 20 10 8.3 4.6 6750 24.5 76.1 310 15 8 12.5 6.8 | 24.9 76.8 315 20 10 13.1 7.2 6500 25.4 77.7 310 15 8 11.8 6.5 | 25.9 78.6 315 19 10 11.6 6.3 6250 26.2 79.2 310 14 7 10.0 5.5 | 26.6 79.9 315 19 10 8.4 4.6 6000 27.0 80.6 310 14 7 9.7 5.3 | 27.3 81.1 315 18 10 9.1 5.0 5750 27.8 82.0 310 14 7 13.4 7.3 | 28.0 82.4 315 18 9 12.4 6.8 5500 29.2 84.6 310 12 6 25.5 14.0 | 29.2 84.6 315 15 8 18.8 10.3 ________________________________________________________________________________ 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