Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
586 UXUS97 KGJT 121307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 706 AM MDT Monday, August 12, 2024 This forecast is for Monday, August 12, 2024: If the trigger temperature of 77.7 F/25.4 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 439 ft/min (2.2 m/s) Maximum height of thermals.................. 13337 ft MSL (8498 ft AGL) Forecast maximum temperature................... 88.0 F/31.6 C Time of trigger temperature.................... 1030 MDT Time of overdevelopment........................ 1400 MDT Middle/high clouds during soaring window....... Broken/overcast thin middle Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 11639 ft MSL (6800 ft AGL) Thermal soaring outlook for Tuesday 08/13...... Good Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:25:27 / 20:12:40 MDT Total possible sunshine........... 13 hr 47 min 13 sec (827 min 13 sec) Altitude of sun at 13:19:03 MDT... 65.17 degrees Upper air data from rawinsonde observation taken on 08/12/2024 at 0600 MDT Freezing level.................. 16176 ft MSL (11337 ft AGL) Convective condensation level... 14597 ft MSL (9758 ft AGL) Lifted condensation level....... 14054 ft MSL (9215 ft AGL) Lifted index.................... -1.9 K index......................... +22.5 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 -68.4 -91.1 245 23 12 6.0 3.3 78.8 173.9 27.8 M M 45000 -59.3 -74.7 260 28 14 4.4 2.4 69.7 157.5 24.1 M M 40000 -50.0 -58.0 250 42 22 6.4 3.5 61.4 142.5 20.2 M M 38000 -46.2 -51.2 245 42 22 8.3 4.6 58.4 137.1 18.7 M M 36000 -40.9 -41.6 250 41 21 7.3 4.0 56.6 133.9 17.9 M M 34000 -36.1 -33.0 245 37 19 6.3 3.5 55.0 131.1 17.3 M M 32000 -31.5 -24.7 255 39 20 6.4 3.5 53.3 128.0 16.4 M M 30000 -27.0 -16.6 255 35 18 7.7 4.2 51.5 124.8 15.4 M M 29000 -25.1 -13.2 250 27 14 5.0 2.8 50.3 122.5 14.6 M M 28000 -23.6 -10.5 260 27 14 5.1 2.8 48.5 119.3 13.4 M M 27000 -22.1 -7.8 265 22 11 5.1 2.8 46.7 116.1 12.1 M M 26000 -20.6 -5.1 265 18 9 4.9 2.7 45.0 113.0 10.8 M M 25000 -18.3 -0.9 270 19 10 8.9 4.9 44.2 111.6 10.3 M M 24000 -15.7 3.7 270 18 9 9.4 5.2 43.9 110.9 10.1 M M 23000 -13.9 7.0 280 19 10 7.3 4.0 42.5 108.6 9.0 M M 22000 -11.7 10.9 285 13 6 7.0 3.9 41.5 106.7 8.3 M M 21000 -9.6 14.7 340 2 1 7.0 3.9 40.6 105.0 7.7 M M 20000 -7.4 18.7 200 2 1 7.0 3.9 39.6 103.2 6.9 M M 19500 -6.5 20.3 200 3 2 7.3 4.0 39.0 102.1 6.4 M M 19000 -5.7 21.7 210 7 4 8.8 4.8 37.4 99.4 5.0 M M 18500 -4.8 23.4 190 8 4 6.3 3.5 36.9 98.4 4.5 M M 18000 -3.9 25.0 205 7 4 7.5 4.1 36.2 97.2 4.0 M M 17500 -2.6 27.3 215 8 4 8.8 4.8 36.1 97.0 3.9 M M 17000 -1.3 29.7 210 9 5 9.2 5.0 36.0 96.7 3.7 M M 16500 -0.2 31.6 220 12 6 4.7 2.6 35.6 96.0 3.4 M M 16000 0.2 32.4 225 16 8 5.9 3.2 34.5 94.2 2.4 M M 15500 1.4 34.5 225 15 8 7.8 4.3 34.2 93.6 2.1 M M 15000 2.6 36.7 225 12 6 7.9 4.3 33.9 93.1 1.8 M M 14500 3.7 38.7 215 12 6 8.0 4.4 33.6 92.6 1.5 M M 14000 4.9 40.8 225 11 6 9.6 5.3 33.4 92.0 1.3 M M 13500 5.6 42.1 240 9 5 -2.4 -1.3 32.7 90.8 0.5 M M 13000 5.4 41.7 275 9 5 4.4 2.4 30.9 87.6 -1.1 629 3.2 12500 6.3 43.3 275 9 5 5.3 2.9 30.3 86.5 -1.7 588 3.0 12000 7.0 44.6 265 9 5 5.1 2.8 29.5 85.2 -2.5 553 2.8 11500 7.8 46.0 255 11 6 7.1 3.9 28.9 84.0 -3.2 515 2.6 11000 8.9 48.0 250 12 6 7.9 4.3 28.6 83.4 -3.5 465 2.4 10500 10.1 50.2 245 10 5 8.1 4.4 28.3 82.9 -3.8 416 2.1 10250 10.7 51.3 230 10 5 9.1 5.0 28.2 82.7 -3.9 390 2.0 10000 11.3 52.3 215 10 5 6.8 3.7 28.1 82.6 -4.0 363 1.8 9750 11.6 52.9 195 9 5 2.2 1.2 27.7 81.8 -4.5 348 1.8 9500 11.8 53.2 185 11 6 5.2 2.8 27.1 80.8 -5.1 336 1.7 9250 12.4 54.3 185 14 7 8.9 4.9 27.0 80.5 -5.3 311 1.6 9000 13.0 55.4 180 17 9 8.4 4.6 26.9 80.4 -5.4 285 1.4 8750 13.6 56.5 180 17 9 8.6 4.7 26.8 80.2 -5.5 259 1.3 8500 14.2 57.6 180 18 9 8.4 4.6 26.7 80.0 -5.6 233 1.2 8250 14.8 58.6 180 20 10 8.9 4.9 26.6 79.9 -5.8 207 1.1 8000 15.4 59.7 180 19 10 6.9 3.8 26.5 79.7 -5.9 181 0.9 7750 15.7 60.3 180 19 10 -1.8 -1.0 26.0 78.7 -6.4 167 0.8 7500 15.3 59.5 175 18 9 -3.0 -1.6 24.9 76.8 -7.5 169 0.9 7250 15.4 59.7 180 16 8 4.5 2.4 24.2 75.6 -8.2 160 0.8 7000 15.8 60.4 185 15 8 6.8 3.7 24.0 75.1 -8.5 140 0.7 6750 16.3 61.3 185 15 8 6.5 3.6 23.7 74.7 -8.8 119 0.6 6500 16.8 62.2 175 15 8 6.6 3.6 23.5 74.2 -9.1 98 0.5 6250 17.2 63.0 175 14 7 6.5 3.6 23.2 73.8 -9.4 77 0.4 6000 17.7 63.9 165 13 7 6.7 3.7 23.0 73.4 -9.7 56 0.3 5750 18.1 64.6 160 14 7 6.0 3.3 22.7 72.9 -10.0 35 0.2 5500 18.6 65.5 150 13 7 8.6 4.7 22.5 72.5 -10.3 14 0.1 5250 19.1 66.4 145 12 6 3.0 1.6 22.4 72.3 -10.5 M M 5000 18.8 65.8 135 12 6 -9.8 -5.4 21.3 70.3 -11.5 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 08/12/2024 at 0900 MDT | 08/12/2024 at 1200 MDT | CAPE... +17.5 LI... +0.7 | CAPE... +185.8 LI... -1.2 CINH... -116.2 K Index... +28.0 | CINH... -41.1 K Index... +28.9 | 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 -64.0 -83.2 240 16 8 2.1 1.2 | -63.8 -82.8 230 17 9 1.6 0.9 45000 -58.8 -73.8 250 24 12 5.8 3.2 | -59.1 -74.4 240 25 13 5.9 3.2 40000 -49.8 -57.6 255 35 18 7.0 3.8 | -50.1 -58.2 250 33 17 6.8 3.7 38000 -45.1 -49.2 245 37 19 7.0 3.8 | -45.5 -49.9 245 36 19 6.8 3.7 36000 -40.9 -41.6 240 39 20 7.0 3.8 | -41.4 -42.5 240 39 20 7.4 4.0 34000 -36.7 -34.1 240 33 17 6.9 3.8 | -36.8 -34.2 235 35 18 7.6 4.2 32000 -32.6 -26.7 245 28 15 7.7 4.2 | -32.2 -26.0 235 31 16 8.4 4.6 30000 -28.5 -19.3 250 24 12 6.9 3.8 | -28.0 -18.4 235 27 14 7.1 3.9 29000 -26.4 -15.5 250 22 11 6.9 3.8 | -25.9 -14.6 235 25 13 7.2 3.9 28000 -24.4 -11.9 255 20 10 6.9 3.8 | -23.8 -10.8 230 24 12 6.8 3.7 27000 -22.4 -8.3 255 19 10 6.9 3.8 | -21.8 -7.2 235 22 11 6.8 3.7 26000 -20.3 -4.5 255 18 9 6.9 3.8 | -19.8 -3.6 235 20 10 6.8 3.7 25000 -18.3 -0.9 255 17 9 6.9 3.8 | -17.8 -0.0 235 19 10 6.8 3.7 24000 -16.3 2.7 255 15 8 6.8 3.8 | -15.8 3.6 235 18 9 6.8 3.7 23000 -13.8 7.2 255 13 7 6.8 3.8 | -13.3 8.1 240 16 8 6.8 3.7 22000 -11.7 10.9 250 11 6 7.4 4.1 | -11.3 11.7 240 15 8 6.3 3.4 21000 -9.5 14.9 240 10 5 7.5 4.1 | -9.5 14.9 235 16 8 6.2 3.4 20000 -7.2 19.0 230 8 4 7.5 4.1 | -7.7 18.1 230 17 9 6.2 3.4 19500 -6.1 21.0 220 8 4 7.1 3.9 | -6.8 19.8 230 17 9 6.2 3.4 19000 -5.2 22.6 225 9 4 6.5 3.5 | -5.9 21.4 230 17 9 6.1 3.4 18500 -4.3 24.3 230 9 5 6.6 3.6 | -5.0 23.0 230 18 9 6.2 3.4 18000 -3.4 25.9 235 10 5 5.8 3.2 | -4.1 24.6 235 18 9 6.0 3.3 17500 -2.6 27.3 235 11 6 5.7 3.1 | -3.3 26.1 235 17 9 6.0 3.3 17000 -1.8 28.8 240 12 6 5.7 3.1 | -2.4 27.7 235 17 9 6.1 3.3 16500 -1.1 30.0 240 13 7 5.4 2.9 | -1.5 29.3 240 17 9 6.3 3.5 16000 -0.3 31.5 240 14 7 5.4 2.9 | -0.6 30.9 240 17 9 6.4 3.5 15500 0.5 32.9 245 15 8 5.8 3.2 | 0.3 32.5 240 16 8 6.4 3.5 15000 1.3 34.3 245 16 8 5.8 3.2 | 1.2 34.2 240 15 8 6.4 3.5 14500 2.1 35.8 245 16 8 5.8 3.2 | 2.1 35.8 245 14 7 7.1 3.9 14000 2.9 37.2 245 15 8 5.8 3.2 | 3.2 37.8 245 14 7 7.3 4.0 13500 3.8 38.8 245 15 8 6.1 3.3 | 4.2 39.6 245 13 7 7.2 3.9 13000 4.7 40.5 250 15 7 6.3 3.5 | 5.2 41.4 240 13 7 7.0 3.8 12500 5.6 42.1 250 14 7 6.4 3.5 | 6.2 43.2 240 12 6 7.0 3.8 12000 6.5 43.7 255 13 7 6.6 3.6 | 7.2 45.0 240 11 6 6.9 3.8 11500 7.5 45.5 255 12 6 6.5 3.5 | 8.2 46.8 235 11 6 6.9 3.8 11000 8.3 46.9 260 11 6 6.0 3.3 | 9.2 48.6 235 10 5 6.7 3.7 10500 9.2 48.6 260 11 5 6.3 3.4 | 10.2 50.4 230 9 4 6.5 3.6 10250 9.6 49.3 260 10 5 6.5 3.6 | 10.6 51.1 230 9 5 7.1 3.9 10000 10.1 50.2 255 10 5 6.2 3.4 | 11.2 52.2 225 8 4 7.9 4.3 9750 10.5 50.9 255 9 5 6.0 3.3 | 11.8 53.2 225 7 4 7.7 4.2 9500 10.9 51.6 255 9 5 6.5 3.5 | 12.3 54.1 220 6 3 7.8 4.3 9250 11.4 52.5 255 8 4 7.5 4.1 | 12.9 55.2 215 6 3 8.0 4.4 9000 11.9 53.4 250 8 4 6.5 3.6 | 13.4 56.1 215 6 3 7.4 4.1 8750 12.4 54.3 250 7 4 5.3 2.9 | 13.9 57.0 215 5 3 7.1 3.9 8500 12.8 55.0 250 6 3 5.8 3.2 | 14.9 58.8 210 5 2 5.9 3.2 8250 13.6 56.5 240 5 3 6.1 3.4 | 15.3 59.5 205 4 2 7.6 4.2 8000 14.1 57.4 235 5 2 6.6 3.6 | 16.0 60.8 205 4 2 10.6 5.8 7750 14.5 58.1 230 4 2 6.0 3.3 | 16.7 62.1 210 4 2 8.9 4.9 7500 14.9 58.8 220 4 2 5.4 2.9 | 17.3 63.1 210 4 2 6.8 3.7 7250 15.3 59.5 210 3 2 5.8 3.2 | 17.8 64.0 205 4 2 8.5 4.6 7000 15.8 60.4 200 3 2 7.3 4.0 | 18.6 65.5 210 4 2 12.3 6.7 6750 16.3 61.3 190 3 1 7.7 4.2 | 19.5 67.1 210 4 2 11.6 6.4 6500 16.8 62.2 180 2 1 6.9 3.8 | 20.3 68.5 210 3 2 9.9 5.4 6250 17.4 63.3 165 2 1 7.6 4.2 | 21.0 69.8 205 3 2 8.9 4.9 6000 18.0 64.4 160 2 1 11.9 6.5 | 21.7 71.1 210 3 2 13.9 7.6 5750 19.1 66.4 150 2 1 17.5 9.6 | 23.3 73.9 210 3 2 28.2 15.5 5500 20.2 68.4 145 2 1 7.9 4.3 | 25.0 77.0 205 2 1 6.7 3.7 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 08/12/2024 at 1500 MDT | 08/12/2024 at 1800 MDT | CAPE... +369.6 LI... -1.6 | CAPE... +274.1 LI... -1.7 CINH... -31.8 K Index... +30.7 | CINH... -40.1 K Index... +29.2 | 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 -63.6 -82.5 225 18 9 1.9 1.0 | -63.8 -82.8 230 19 10 1.8 1.0 45000 -58.9 -74.0 235 24 12 5.4 3.0 | -59.1 -74.4 230 25 13 5.5 3.0 40000 -50.5 -58.9 245 31 16 6.8 3.7 | -50.4 -58.7 235 28 14 7.0 3.8 38000 -45.9 -50.6 240 34 18 6.8 3.7 | -45.7 -50.3 235 29 15 7.0 3.8 36000 -41.8 -43.2 240 38 19 7.5 4.1 | -41.5 -42.7 235 30 16 7.5 4.1 34000 -37.1 -34.8 235 35 18 7.8 4.3 | -36.9 -34.4 235 29 15 7.7 4.2 32000 -32.4 -26.3 230 33 17 8.7 4.8 | -32.2 -26.0 235 27 14 8.5 4.7 30000 -28.0 -18.4 230 29 15 7.4 4.1 | -27.7 -17.9 230 25 13 7.6 4.1 29000 -25.8 -14.4 230 27 14 7.4 4.1 | -25.5 -13.9 230 25 13 7.6 4.2 28000 -23.7 -10.7 230 25 13 6.9 3.8 | -23.3 -9.9 230 24 12 7.0 3.8 27000 -21.6 -6.9 230 22 12 6.9 3.8 | -21.3 -6.3 230 23 12 6.9 3.8 26000 -19.6 -3.3 230 20 10 6.9 3.8 | -19.2 -2.6 230 21 11 7.0 3.8 25000 -17.6 0.3 235 17 9 6.8 3.8 | -17.2 1.0 235 20 10 6.8 3.7 24000 -15.1 4.8 240 15 8 6.7 3.6 | -15.4 4.3 235 19 10 6.0 3.3 23000 -13.1 8.4 245 14 7 6.7 3.7 | -13.1 8.4 230 16 8 6.0 3.3 22000 -11.1 12.0 255 13 7 6.7 3.7 | -11.3 11.7 230 15 8 6.9 3.8 21000 -9.2 15.4 255 14 7 6.7 3.7 | -9.2 15.4 235 14 7 7.1 3.9 20000 -7.3 18.9 260 15 7 6.8 3.7 | -7.1 19.2 240 14 7 7.1 3.9 19500 -6.3 20.7 260 15 8 6.6 3.6 | -6.1 21.0 240 14 7 7.1 3.9 19000 -5.4 22.3 265 16 8 6.2 3.4 | -5.1 22.8 245 14 7 7.0 3.9 18500 -4.5 23.9 265 16 8 6.2 3.4 | -4.1 24.6 250 14 7 7.1 3.9 18000 -3.6 25.5 265 17 9 6.0 3.3 | -3.1 26.4 250 15 8 6.6 3.6 17500 -2.8 27.0 265 17 9 6.0 3.3 | -2.1 28.2 250 15 8 6.6 3.6 17000 -2.0 28.4 270 17 9 6.0 3.3 | -1.2 29.8 255 15 8 6.6 3.6 16500 -1.1 30.0 270 16 8 6.0 3.3 | -0.3 31.5 255 15 8 6.5 3.6 16000 -0.2 31.6 270 15 8 6.0 3.3 | 0.7 33.3 255 15 8 6.5 3.6 15500 0.6 33.1 270 15 8 6.2 3.4 | 1.6 34.9 255 15 8 7.1 3.9 15000 1.5 34.7 270 14 7 6.2 3.4 | 2.6 36.7 255 15 8 7.1 3.9 14500 2.5 36.5 270 13 7 6.9 3.8 | 3.7 38.7 255 15 7 7.5 4.1 14000 3.5 38.3 265 13 7 7.2 4.0 | 4.8 40.6 255 14 7 7.7 4.2 13500 4.5 40.1 265 12 6 7.4 4.1 | 5.9 42.6 255 14 7 7.7 4.2 13000 5.6 42.1 265 12 6 7.7 4.2 | 7.0 44.6 250 14 7 7.9 4.3 12500 6.8 44.2 265 12 6 7.7 4.2 | 8.1 46.6 250 14 7 8.0 4.4 12000 7.9 46.2 260 12 6 7.9 4.3 | 9.3 48.7 245 14 7 8.4 4.6 11500 9.0 48.2 255 12 6 7.9 4.3 | 10.5 50.9 245 13 7 8.4 4.6 11000 10.2 50.4 250 11 6 7.9 4.4 | 11.7 53.1 245 13 7 8.1 4.4 10500 11.3 52.3 245 11 6 7.8 4.3 | 12.9 55.2 245 12 6 9.8 5.4 10250 11.8 53.2 250 10 5 7.9 4.3 | 13.6 56.5 240 12 6 10.1 5.5 10000 12.4 54.3 245 9 5 8.3 4.6 | 14.3 57.7 240 11 6 8.2 4.5 9750 13.0 55.4 245 9 5 8.1 4.4 | 14.9 58.8 240 10 5 8.7 4.8 9500 13.6 56.5 240 9 5 8.7 4.8 | 15.5 59.9 240 10 5 8.7 4.8 9250 14.3 57.7 240 8 4 9.7 5.3 | 16.1 61.0 240 9 5 8.9 4.9 9000 15.0 59.0 245 8 4 8.9 4.9 | 16.8 62.2 240 8 4 8.4 4.6 8750 15.6 60.1 240 8 4 8.0 4.4 | 17.4 63.3 240 8 4 8.2 4.5 8500 16.7 62.1 235 8 4 8.0 4.4 | 18.5 65.3 235 6 3 6.5 3.5 8250 17.4 63.3 240 7 4 8.7 4.8 | 19.0 66.2 235 5 2 7.7 4.2 8000 18.0 64.4 235 7 4 10.0 5.5 | 19.7 67.5 230 4 2 9.8 5.4 7750 18.8 65.8 235 7 4 8.8 4.8 | 20.3 68.5 225 4 2 9.0 4.9 7500 19.3 66.7 235 7 4 7.3 4.0 | 21.0 69.8 225 3 2 8.0 4.4 7250 19.9 67.8 235 7 3 8.1 4.5 | 21.6 70.9 225 3 1 8.4 4.6 7000 20.6 69.1 235 6 3 10.4 5.7 | 22.3 72.1 220 3 1 11.0 6.0 6750 21.3 70.3 230 6 3 10.1 5.5 | 23.1 73.6 215 3 2 10.9 6.0 6500 22.0 71.6 230 6 3 9.1 5.0 | 23.9 75.0 215 2 1 9.8 5.4 6250 22.7 72.9 230 6 3 8.3 4.6 | 24.6 76.3 215 2 1 9.8 5.4 6000 23.3 73.9 230 5 3 11.9 6.5 | 25.3 77.5 215 2 1 10.1 5.5 5750 24.6 76.3 230 5 3 23.1 12.7 | 26.2 79.2 215 2 1 14.7 8.1 5500 26.1 79.0 230 5 3 13.5 7.4 | 27.6 81.7 210 1 1 24.2 13.3 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