Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
859 UXUS97 KGJT 141307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Tuesday, May 14, 2024 This forecast is for Tuesday, May 14, 2024: If the trigger temperature of 70.1 F/21.2 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1107 ft/min (5.6 m/s) Maximum height of thermals.................. 17182 ft MSL (12349 ft AGL) Forecast maximum temperature................... 80.0 F/27.1 C Time of trigger temperature.................... 0945 MDT Time of overdevelopment........................ 1800 MDT Middle/high clouds during soaring window....... None Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 13833 ft MSL (9000 ft AGL) Thermal soaring outlook for Wednesday 05/15.... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:01:09 / 20:19:50 MDT Total possible sunshine........... 14 hr 18 min 41 sec (858 min 41 sec) Altitude of sun at 13:10:30 MDT... 69.64 degrees Upper air data from rawinsonde observation taken on 05/14/2024 at 0600 MDT Freezing level.................. 12418 ft MSL (7585 ft AGL) Convective condensation level... 14629 ft MSL (9796 ft AGL) Lifted condensation level....... 15850 ft MSL (11018 ft AGL) Lifted index.................... -2.6 K index......................... +23.5 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 -56.1 -69.0 230 26 13 2.8 1.5 105.5 221.9 45.2 M M 45000 -52.8 -63.0 220 25 13 3.7 2.0 86.2 187.2 36.5 M M 40000 -57.6 -71.7 265 28 14 -9.2 -5.0 55.5 131.9 18.9 M M 38000 -58.1 -72.6 270 34 18 4.6 2.5 45.9 114.6 13.0 M M 36000 -54.5 -66.1 260 38 20 8.1 4.4 41.4 106.6 10.3 M M 34000 -49.9 -57.8 260 37 19 7.6 4.1 39.8 103.7 9.4 M M 32000 -45.3 -49.5 255 34 17 7.6 4.1 38.0 100.5 8.3 M M 30000 -40.7 -41.3 255 31 16 7.5 4.1 36.3 97.3 7.2 M M 29000 -38.5 -37.3 250 27 14 7.5 4.1 35.4 95.7 6.6 M M 28000 -36.3 -33.3 255 27 14 8.1 4.5 34.5 94.1 6.0 M M 27000 -33.7 -28.7 270 30 15 8.1 4.4 33.9 93.1 5.6 M M 26000 -31.5 -24.7 275 28 14 7.3 4.0 33.0 91.5 5.0 M M 25000 -29.3 -20.7 280 28 15 8.7 4.8 32.2 90.0 4.4 M M 24000 -26.7 -16.1 280 27 14 9.4 5.1 31.8 89.2 4.0 M M 23000 -24.0 -11.2 280 30 15 8.7 4.8 31.5 88.7 3.8 M M 22000 -21.7 -7.1 265 25 13 6.3 3.5 30.8 87.4 3.2 M M 21000 -19.9 -3.8 260 33 17 6.4 3.5 29.6 85.2 2.2 M M 20000 -17.7 0.1 265 31 16 7.9 4.3 28.7 83.6 1.5 M M 19500 -15.9 3.4 270 30 15 7.9 4.3 28.2 82.7 1.1 M M 19000 -14.7 5.5 265 29 15 8.3 4.5 27.8 82.1 0.8 M M 18500 -13.4 7.9 265 31 16 8.7 4.8 27.7 81.8 0.6 M M 18000 -12.1 10.2 260 29 15 8.3 4.5 27.5 81.5 0.5 M M 17500 -11.0 12.2 255 25 13 7.8 4.3 27.1 80.9 0.1 M M 17000 -9.9 14.2 250 22 11 7.8 4.3 26.8 80.3 -0.2 1080 5.5 16500 -8.7 16.3 250 21 11 7.8 4.3 26.5 79.7 -0.5 1031 5.2 16000 -7.7 18.1 260 22 11 5.2 2.9 26.0 78.8 -1.0 987 5.0 15500 -7.1 19.2 270 20 10 4.8 2.6 25.1 77.3 -1.8 952 4.8 15000 -6.3 20.7 275 19 10 7.3 4.0 24.4 76.0 -2.5 914 4.6 14500 -5.1 22.8 280 19 10 8.2 4.5 24.2 75.6 -2.7 862 4.4 14000 -3.8 25.2 265 20 10 8.3 4.6 24.0 75.2 -2.9 811 4.1 13500 -2.6 27.3 270 18 9 8.3 4.6 23.8 74.8 -3.2 759 3.9 13000 -1.4 29.5 280 15 8 8.3 4.6 23.6 74.4 -3.4 707 3.6 12500 -0.1 31.8 275 17 9 8.3 4.6 23.3 74.0 -3.7 656 3.3 12000 1.1 34.0 290 17 9 8.3 4.6 23.1 73.6 -3.9 604 3.1 11500 2.3 36.1 300 15 8 8.3 4.6 22.8 73.1 -4.2 552 2.8 11000 3.5 38.3 315 14 7 8.3 4.6 22.6 72.7 -4.5 500 2.5 10500 4.8 40.6 315 14 7 8.3 4.5 22.3 72.2 -4.7 449 2.3 10250 5.4 41.7 310 12 6 8.5 4.7 22.2 72.0 -4.9 423 2.1 10000 6.0 42.8 310 13 7 8.9 4.9 22.1 71.9 -5.0 396 2.0 9750 6.7 44.1 305 14 7 9.0 4.9 22.1 71.8 -5.0 368 1.9 9500 7.4 45.3 295 14 7 9.0 4.9 22.0 71.7 -5.1 341 1.7 9250 8.0 46.4 305 12 6 9.0 4.9 22.0 71.6 -5.2 314 1.6 9000 8.7 47.7 320 11 5 9.0 4.9 21.9 71.5 -5.2 286 1.5 8750 9.4 48.9 315 12 6 9.0 4.9 21.9 71.4 -5.3 259 1.3 8500 10.0 50.0 295 13 7 9.0 4.9 21.8 71.3 -5.4 231 1.2 8250 10.7 51.3 305 11 6 9.0 4.9 21.8 71.2 -5.4 204 1.0 8000 11.4 52.5 320 9 5 9.0 4.9 21.7 71.1 -5.5 177 0.9 7750 12.1 53.8 330 10 5 9.0 4.9 21.7 71.0 -5.6 149 0.8 7500 12.7 54.9 345 8 4 9.0 4.9 21.6 70.9 -5.7 122 0.6 7250 13.4 56.1 005 8 4 9.0 4.9 21.5 70.8 -5.8 94 0.5 7000 14.1 57.4 345 9 4 9.0 4.9 21.5 70.7 -5.8 67 0.3 6750 14.7 58.5 340 8 4 9.0 4.9 21.4 70.5 -5.9 39 0.2 6500 15.4 59.7 330 7 4 9.0 4.9 21.3 70.4 -6.0 12 0.1 6250 16.1 61.0 315 7 4 9.1 5.0 21.3 70.3 -6.1 M M 6000 16.7 62.1 305 7 4 6.0 3.3 21.1 70.1 -6.3 M M 5750 17.0 62.6 310 4 2 4.9 2.7 20.7 69.3 -6.7 M M 5500 17.3 63.1 050 1 1 1.5 0.8 20.4 68.6 -7.2 M M 5250 17.1 62.8 105 2 1 -1.5 -0.8 19.5 67.1 -8.0 M M 5000 17.2 63.0 165 5 2 3.3 1.8 18.9 65.9 -8.7 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 05/14/2024 at 0900 MDT | 05/14/2024 at 1200 MDT | CAPE... +8.4 LI... -0.6 | CAPE... +226.1 LI... -1.5 CINH... -31.9 K Index... +25.0 | CINH... -14.7 K Index... +27.0 | 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 -56.0 -68.8 240 20 10 1.4 0.8 | -55.3 -67.5 250 18 9 1.8 1.0 45000 -54.3 -65.7 225 17 9 -2.4 -1.3 | -53.1 -63.6 240 19 10 -3.7 -2.0 40000 -57.7 -71.9 255 28 14 -2.3 -1.3 | -58.1 -72.6 250 30 15 -3.4 -1.9 38000 -56.2 -69.2 255 31 16 4.4 2.4 | -56.7 -70.1 245 33 17 4.9 2.7 36000 -53.5 -64.3 250 33 17 4.4 2.4 | -53.7 -64.7 245 35 18 4.9 2.7 34000 -50.2 -58.4 250 34 17 7.1 3.9 | -50.3 -58.5 245 36 18 7.0 3.9 32000 -46.0 -50.8 255 32 17 7.1 3.9 | -46.1 -51.0 245 33 17 7.0 3.8 30000 -41.5 -42.7 255 31 16 7.9 4.4 | -41.7 -43.1 250 30 16 7.6 4.2 29000 -39.1 -38.4 255 30 16 7.9 4.4 | -39.4 -38.9 255 29 15 7.6 4.2 28000 -36.7 -34.1 260 30 15 8.0 4.4 | -37.2 -35.0 255 29 15 7.6 4.2 27000 -34.4 -29.9 260 29 15 8.0 4.4 | -34.9 -30.8 260 28 14 8.2 4.5 26000 -32.0 -25.6 265 27 14 8.0 4.4 | -32.4 -26.3 265 27 14 8.1 4.4 25000 -29.6 -21.3 265 26 13 8.0 4.4 | -30.0 -22.0 265 26 13 8.1 4.5 24000 -27.2 -17.0 270 25 13 7.6 4.2 | -27.0 -16.6 270 25 13 7.8 4.3 23000 -24.4 -11.9 270 25 13 7.6 4.1 | -24.7 -12.5 270 25 13 7.9 4.3 22000 -22.2 -8.0 275 25 13 7.6 4.2 | -22.3 -8.1 270 24 12 7.8 4.3 21000 -20.0 -4.0 275 25 13 7.4 4.0 | -20.1 -4.2 270 24 12 7.2 3.9 20000 -17.8 -0.0 275 25 13 7.4 4.1 | -18.0 -0.4 270 24 12 7.2 4.0 19500 -16.7 1.9 275 25 13 7.4 4.1 | -17.0 1.4 270 23 12 7.2 4.0 19000 -15.7 3.7 275 25 13 7.6 4.2 | -15.9 3.4 270 23 12 7.5 4.1 18500 -14.5 5.9 275 25 13 8.2 4.5 | -14.7 5.5 270 23 12 8.4 4.6 18000 -13.3 8.1 275 25 13 8.2 4.5 | -13.5 7.7 270 23 12 8.4 4.6 17500 -12.1 10.2 275 24 12 8.2 4.5 | -12.3 9.9 270 23 12 8.5 4.7 17000 -10.9 12.4 275 24 12 8.3 4.5 | -11.1 12.0 270 22 11 8.5 4.7 16500 -9.7 14.5 275 23 12 8.2 4.5 | -9.8 14.4 270 22 11 8.6 4.7 16000 -8.5 16.7 280 22 11 8.2 4.5 | -8.6 16.5 270 21 11 8.7 4.8 15500 -7.3 18.9 280 21 11 8.2 4.5 | -7.3 18.9 270 20 10 8.7 4.8 15000 -6.1 21.0 280 20 10 8.1 4.4 | -6.0 21.2 270 19 10 8.4 4.6 14500 -4.9 23.2 280 19 10 8.1 4.5 | -4.8 23.4 270 18 9 8.5 4.6 14000 -3.7 25.3 280 18 9 8.0 4.4 | -3.6 25.5 270 17 9 8.4 4.6 13500 -2.5 27.5 280 17 9 8.0 4.4 | -2.3 27.9 270 16 8 8.4 4.6 13000 -1.3 29.7 280 16 8 8.7 4.8 | -1.1 30.0 270 15 8 8.8 4.8 12500 -0.0 32.0 280 14 7 8.8 4.8 | 0.3 32.5 270 14 7 8.9 4.9 12000 1.3 34.3 285 13 7 8.9 4.9 | 1.6 34.9 275 13 7 9.1 5.0 11500 2.6 36.7 280 12 6 8.9 4.9 | 3.0 37.4 275 12 6 9.2 5.1 11000 3.9 39.0 280 11 6 8.1 4.4 | 4.3 39.7 275 12 6 8.4 4.6 10500 5.1 41.2 280 10 5 6.9 3.8 | 5.5 41.9 280 11 6 6.9 3.8 10250 5.7 42.3 280 9 5 10.6 5.8 | 6.1 43.0 280 11 6 11.6 6.4 10000 6.6 43.9 280 9 5 11.1 6.1 | 7.1 44.8 280 11 5 12.5 6.8 9750 7.2 45.0 280 9 5 7.6 4.2 | 7.8 46.0 280 10 5 8.2 4.5 9500 7.9 46.2 280 9 5 8.7 4.8 | 8.5 47.3 280 10 5 9.8 5.4 9250 8.5 47.3 280 8 4 7.8 4.3 | 9.2 48.6 280 10 5 7.6 4.2 9000 9.1 48.4 280 8 4 7.7 4.2 | 9.7 49.5 285 10 5 8.2 4.5 8750 9.7 49.5 280 8 4 8.1 4.4 | 11.2 52.2 285 9 5 10.0 5.5 8500 10.9 51.6 275 6 3 7.3 4.0 | 11.9 53.4 285 8 4 8.9 4.9 8250 11.4 52.5 275 6 3 6.1 3.3 | 12.5 54.5 285 8 4 8.4 4.6 8000 11.8 53.2 275 5 3 6.3 3.4 | 13.2 55.8 285 8 4 10.0 5.5 7750 12.3 54.1 270 4 2 6.9 3.8 | 14.0 57.2 285 8 4 10.7 5.9 7500 12.8 55.0 255 3 2 5.1 2.8 | 14.7 58.5 285 7 4 9.2 5.0 7250 13.0 55.4 255 2 1 3.6 2.0 | 15.4 59.7 290 7 4 8.1 4.4 7000 13.4 56.1 250 2 1 6.8 3.7 | 16.1 61.0 290 7 4 10.6 5.8 6750 14.0 57.2 210 1 1 8.5 4.7 | 16.9 62.4 285 7 3 11.8 6.5 6500 14.5 58.1 175 1 1 8.1 4.5 | 17.7 63.9 285 6 3 10.8 5.9 6250 15.2 59.4 160 1 1 8.6 4.7 | 18.6 65.5 290 6 3 11.1 6.1 6000 15.8 60.4 150 2 1 7.6 4.1 | 19.3 66.7 295 6 3 8.4 4.6 5750 16.4 61.5 150 2 1 11.4 6.2 | 20.0 68.0 285 6 3 13.1 7.2 5500 18.2 64.8 135 2 1 46.2 25.4 | 22.8 73.0 295 6 3 81.8 44.9 5250 M M M M M M M | M M M M M M M 5000 M M M M M M M | M M M M M M M 05/14/2024 at 1500 MDT | 05/14/2024 at 1800 MDT | CAPE... +331.9 LI... -1.4 | CAPE... +191.4 LI... -0.5 CINH... -14.5 K Index... +25.3 | CINH... -13.3 K Index... +27.8 | 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 -55.5 -67.9 250 18 9 1.1 0.6 | -55.1 -67.2 250 21 11 2.0 1.1 45000 -54.3 -65.7 250 21 11 -2.7 -1.5 | -52.8 -63.0 260 26 13 -4.1 -2.2 40000 -58.1 -72.6 240 30 16 -2.2 -1.2 | -58.2 -72.8 255 35 18 -3.7 -2.0 38000 -56.5 -69.7 240 34 17 4.3 2.4 | -57.0 -70.6 250 37 19 4.6 2.5 36000 -53.9 -65.0 240 37 19 4.3 2.4 | -54.3 -65.7 245 39 20 4.6 2.5 34000 -50.6 -59.1 245 37 19 7.4 4.1 | -50.9 -59.6 245 38 20 7.4 4.0 32000 -46.2 -51.2 245 35 18 7.4 4.1 | -46.5 -51.7 245 33 17 7.4 4.0 30000 -41.6 -42.9 250 32 16 8.1 4.4 | -41.9 -43.4 255 29 15 8.0 4.4 29000 -39.1 -38.4 255 31 16 8.1 4.4 | -39.5 -39.1 260 27 14 8.0 4.4 28000 -36.7 -34.1 255 29 15 8.1 4.5 | -37.1 -34.8 265 26 14 8.0 4.4 27000 -34.3 -29.7 255 28 15 8.0 4.4 | -34.7 -30.5 270 26 13 8.9 4.9 26000 -31.9 -25.4 255 28 14 8.0 4.4 | -32.0 -25.6 275 27 14 8.8 4.8 25000 -29.5 -21.1 260 27 14 8.0 4.4 | -29.4 -20.9 275 27 14 8.8 4.8 24000 -26.5 -15.7 260 27 14 8.0 4.4 | -26.8 -16.2 275 27 14 8.4 4.6 23000 -24.2 -11.6 260 27 14 8.0 4.4 | -23.7 -10.7 280 26 13 8.3 4.5 22000 -21.8 -7.2 255 26 14 8.0 4.4 | -21.3 -6.3 280 25 13 8.3 4.5 21000 -19.5 -3.1 255 26 13 7.6 4.2 | -18.9 -2.0 280 24 13 7.6 4.2 20000 -17.2 1.0 260 26 13 7.7 4.2 | -16.7 1.9 280 23 12 7.6 4.2 19500 -16.1 3.0 260 26 13 7.7 4.2 | -15.6 3.9 285 23 12 7.7 4.2 19000 -15.0 5.0 260 25 13 7.7 4.2 | -14.4 6.1 285 22 11 7.7 4.2 18500 -13.8 7.2 260 25 13 7.8 4.3 | -13.3 8.1 285 22 11 7.6 4.2 18000 -12.7 9.1 260 24 13 7.8 4.3 | -12.2 10.0 285 21 11 7.6 4.2 17500 -11.5 11.3 260 24 12 8.1 4.4 | -11.1 12.0 290 20 11 7.2 4.0 17000 -10.4 13.3 260 23 12 8.2 4.5 | -10.1 13.8 290 20 10 7.1 3.9 16500 -9.2 15.4 260 22 11 8.3 4.5 | -9.1 15.6 290 19 10 7.2 3.9 16000 -7.9 17.8 260 21 11 8.5 4.7 | -8.0 17.6 290 18 9 7.2 4.0 15500 -6.7 19.9 260 21 11 8.5 4.7 | -6.9 19.6 290 18 9 7.1 3.9 15000 -5.4 22.3 265 20 10 8.8 4.8 | -5.8 21.6 290 17 9 8.3 4.6 14500 -4.1 24.6 265 19 10 8.7 4.8 | -4.6 23.7 290 17 8 8.2 4.5 14000 -2.8 27.0 265 18 10 9.0 4.9 | -3.4 25.9 290 16 8 8.6 4.7 13500 -1.5 29.3 270 18 9 9.0 4.9 | -2.1 28.2 285 16 8 8.6 4.7 13000 -0.1 31.8 270 17 9 9.2 5.0 | -0.8 30.6 285 15 8 8.9 4.9 12500 1.2 34.2 275 17 9 9.2 5.1 | 0.6 33.1 285 15 8 9.1 5.0 12000 2.6 36.7 275 16 8 9.1 5.0 | 1.9 35.4 285 15 8 9.0 5.0 11500 3.9 39.0 280 15 8 8.9 4.9 | 3.2 37.8 280 15 8 9.0 4.9 11000 5.2 41.4 280 15 8 8.4 4.6 | 4.6 40.3 280 14 7 8.2 4.5 10500 6.4 43.5 280 15 8 7.3 4.0 | 5.7 42.3 285 14 7 6.5 3.6 10250 7.0 44.6 280 15 8 10.8 5.9 | 6.2 43.2 285 13 7 11.3 6.2 10000 8.0 46.4 285 14 7 11.6 6.4 | 7.2 45.0 280 14 7 11.6 6.4 9750 8.6 47.5 285 14 7 8.7 4.8 | 7.8 46.0 280 13 7 7.3 4.0 9500 9.3 48.7 285 14 7 9.4 5.2 | 8.4 47.1 285 13 7 8.1 4.4 9250 10.0 50.0 285 14 7 9.3 5.1 | 9.0 48.2 285 12 6 9.2 5.0 9000 10.7 51.3 290 14 7 9.4 5.2 | 9.8 49.6 280 12 6 9.7 5.3 8750 12.1 53.8 295 14 7 9.2 5.1 | 10.4 50.7 280 12 6 8.4 4.6 8500 12.8 55.0 295 14 7 9.6 5.3 | 11.1 52.0 280 11 6 8.9 4.9 8250 13.5 56.3 295 14 7 9.8 5.4 | 12.3 54.1 285 11 6 8.2 4.5 8000 14.2 57.6 300 14 7 9.2 5.1 | 13.0 55.4 290 10 5 8.7 4.8 7750 14.9 58.8 300 14 7 9.2 5.0 | 13.6 56.5 285 9 5 9.2 5.0 7500 15.6 60.1 305 13 7 9.0 4.9 | 14.3 57.7 285 9 4 8.0 4.4 7250 16.2 61.2 305 14 7 8.8 4.8 | 14.8 58.6 290 9 4 6.7 3.7 7000 16.9 62.4 305 14 7 9.1 5.0 | 15.4 59.7 295 9 4 8.8 4.8 6750 17.6 63.7 310 13 7 9.1 5.0 | 16.1 61.0 290 8 4 10.2 5.6 6500 18.3 64.9 310 13 7 10.8 5.9 | 16.8 62.2 285 7 3 9.7 5.3 6250 19.2 66.6 310 13 7 13.5 7.4 | 17.6 63.7 295 7 4 10.1 5.5 6000 20.1 68.2 315 13 7 7.7 4.2 | 18.3 64.9 300 7 4 8.0 4.4 5750 20.5 68.9 310 12 6 10.0 5.5 | 18.8 65.8 290 6 3 9.0 4.9 5500 23.5 74.3 315 12 6 94.4 51.8 | 20.5 68.9 305 5 3 46.2 25.3 5250 M M M M M M M | M M M M M M M 5000 M M M M M M M | M M M M M M M ________________________________________________________________________________ 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 at Walker Field in Grand Junction, Colorado at North Latitude: 39 deg 07 min 00.001 sec West Longitude: 108 deg 31 min 59.998 sec Elevation: 4839 feet (1475 meters) and may not be representative of other areas along the Western Slope of Colorado. 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