Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
224 UXUS97 KGJT 091307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Wednesday, October 9, 2024 This forecast is for Wednesday, October 9, 2024: If the trigger temperature of 77.5 F/25.3 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1302 ft/min (6.6 m/s) Maximum height of thermals.................. 18404 ft MSL (13565 ft AGL) Forecast maximum temperature................... 84.0 F/29.3 C Time of trigger temperature.................... 1230 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................. 9569 ft MSL (4730 ft AGL) Thermal soaring outlook for Thursday 10/10..... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 07:18:40 / 18:43:42 MDT Total possible sunshine........... 11 hr 25 min 2 sec (685 min 2 sec) Altitude of sun at 13:01:11 MDT... 44.21 degrees Upper air data from rawinsonde observation taken on 10/09/2024 at 0600 MDT Freezing level.................. 13930 ft MSL (9091 ft AGL) Convective condensation level... 16771 ft MSL (11932 ft AGL) Lifted condensation level....... 17269 ft MSL (12430 ft AGL) Lifted index.................... -0.7 K index......................... +20.9 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 -62.6 -80.7 280 20 10 5.0 2.8 93.0 199.4 36.9 M M 45000 -56.3 -69.3 290 13 7 2.3 1.3 78.0 172.4 30.3 M M 40000 -51.3 -60.3 310 15 8 -2.5 -1.3 62.9 145.1 22.4 M M 38000 -51.4 -60.5 305 19 10 3.1 1.7 53.9 129.1 17.0 M M 36000 -49.4 -56.9 295 16 8 4.4 2.4 48.3 119.4 13.5 M M 34000 -47.3 -53.1 310 19 10 3.3 1.8 43.0 109.3 10.1 M M 32000 -43.8 -46.8 285 12 6 7.5 4.1 38.9 101.9 7.3 M M 30000 -39.4 -38.9 285 16 8 9.6 5.3 36.9 98.4 6.0 M M 29000 -36.6 -33.9 285 15 8 9.4 5.1 36.7 98.1 6.0 M M 28000 -33.8 -28.8 285 14 7 9.4 5.1 36.6 97.8 5.9 M M 27000 -31.0 -23.8 285 18 9 9.2 5.0 36.4 97.4 5.8 M M 26000 -28.5 -19.3 275 15 8 8.7 4.8 35.9 96.6 5.5 M M 25000 -25.8 -14.4 275 14 7 7.6 4.2 35.6 96.1 5.3 M M 24000 -23.0 -9.4 290 13 7 7.8 4.3 35.5 95.8 5.3 M M 23000 -21.1 -6.0 290 12 6 6.4 3.5 34.3 93.7 4.3 M M 22000 -19.3 -2.7 295 15 8 6.3 3.5 33.0 91.4 3.3 M M 21000 -17.4 0.7 290 15 8 6.3 3.5 31.7 89.1 2.2 M M 20000 -15.4 4.3 295 14 7 7.1 3.9 30.7 87.2 1.3 M M 19500 -14.4 6.1 295 15 8 7.3 4.0 30.2 86.4 0.9 M M 19000 -13.3 8.1 285 16 8 7.6 4.2 29.8 85.7 0.5 M M 18500 -12.2 10.0 280 13 7 7.6 4.2 29.5 85.0 0.1 M M 18000 -11.1 12.0 280 13 7 7.9 4.3 29.1 84.4 -0.2 1274 6.5 17500 -9.3 15.3 270 13 7 7.9 4.3 28.6 83.5 -0.6 1199 6.1 17000 -8.1 17.4 265 14 7 8.4 4.6 28.3 83.0 -0.9 1149 5.8 16500 -6.8 19.8 270 17 9 9.2 5.1 28.2 82.8 -1.1 1095 5.6 16000 -5.5 22.1 270 15 8 9.2 5.0 28.1 82.7 -1.1 1040 5.3 15500 -4.1 24.6 270 14 7 9.2 5.0 28.1 82.5 -1.2 984 5.0 15000 -2.7 27.1 275 12 6 9.2 5.0 28.0 82.3 -1.3 928 4.7 14500 -1.4 29.5 285 10 5 9.2 5.0 27.9 82.2 -1.4 873 4.4 14000 -0.0 32.0 290 12 6 9.2 5.0 27.8 82.0 -1.5 817 4.2 13500 1.3 34.3 295 13 7 9.2 5.0 27.7 81.8 -1.7 762 3.9 13000 2.7 36.9 300 14 7 9.1 5.0 27.6 81.6 -1.8 706 3.6 12500 4.0 39.2 310 11 6 9.0 4.9 27.5 81.4 -1.9 651 3.3 12000 5.4 41.7 300 9 5 9.0 4.9 27.4 81.2 -2.0 596 3.0 11500 6.7 44.1 295 7 4 9.0 4.9 27.2 81.0 -2.2 541 2.7 11000 8.1 46.6 295 6 3 9.0 4.9 27.1 80.8 -2.3 486 2.5 10500 9.4 48.9 260 5 3 8.6 4.7 27.0 80.6 -2.4 431 2.2 10250 10.0 50.0 230 5 3 7.8 4.3 26.8 80.3 -2.6 406 2.1 10000 10.6 51.1 220 5 3 7.7 4.2 26.7 80.1 -2.7 381 1.9 9750 11.1 52.0 230 3 1 7.7 4.2 26.5 79.8 -2.9 357 1.8 9500 11.7 53.1 280 1 0 7.7 4.2 26.4 79.5 -3.0 332 1.7 9250 12.3 54.1 200 1 0 7.7 4.2 26.2 79.2 -3.2 308 1.6 9000 12.9 55.2 170 2 1 7.7 4.2 26.1 78.9 -3.4 283 1.4 8750 13.4 56.1 140 2 1 7.7 4.2 25.9 78.6 -3.5 259 1.3 8500 14.0 57.2 120 3 1 7.7 4.2 25.8 78.4 -3.7 234 1.2 8250 14.6 58.3 135 3 2 7.7 4.2 25.6 78.1 -3.9 210 1.1 8000 15.2 59.4 160 4 2 7.7 4.2 25.4 77.8 -4.0 185 0.9 7750 15.7 60.3 150 4 2 7.9 4.3 25.3 77.5 -4.2 161 0.8 7500 16.2 61.2 135 3 2 4.1 2.3 25.0 77.1 -4.5 138 0.7 7250 16.3 61.3 120 4 2 0.4 0.2 24.4 75.9 -5.1 127 0.6 7000 16.3 61.3 120 7 3 -2.4 -1.3 23.6 74.5 -5.9 121 0.6 6750 16.1 61.0 120 8 4 -1.4 -0.7 22.6 72.7 -6.8 120 0.6 6500 16.2 61.2 125 11 5 4.7 2.6 22.0 71.7 -7.4 108 0.5 6250 16.7 62.1 125 13 7 6.4 3.5 21.8 71.2 -7.7 88 0.4 6000 17.1 62.8 125 16 8 5.2 2.9 21.5 70.6 -8.0 67 0.3 5750 17.5 63.5 120 15 8 7.8 4.3 21.2 70.1 -8.4 48 0.2 5500 17.9 64.2 120 16 8 -2.0 -1.1 20.9 69.6 -8.8 29 0.1 5250 17.0 62.6 115 17 9 -17.0 -9.3 19.3 66.7 -10.4 48 0.2 5000 15.6 60.1 120 18 9 -19.5 -10.7 17.2 62.9 -12.5 82 0.4 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 10/09/2024 at 0900 MDT | 10/09/2024 at 1200 MDT | CAPE... 0.0 LI... -0.2 | CAPE... +2.6 LI... +0.4 CINH... -0.1 K Index... +22.5 | CINH... -0.7 K Index... +21.3 | 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 -61.9 -79.4 285 12 6 3.8 2.1 | -62.4 -80.3 285 14 7 3.3 1.8 45000 -56.1 -69.0 305 16 8 3.2 1.8 | -57.0 -70.6 300 17 9 3.8 2.1 40000 -51.3 -60.3 355 17 9 2.6 1.4 | -51.3 -60.3 350 12 6 3.1 1.7 38000 -50.0 -58.0 360 19 10 2.3 1.3 | -49.8 -57.6 005 16 8 2.5 1.4 36000 -48.6 -55.5 005 21 11 2.3 1.3 | -48.3 -54.9 015 20 10 2.4 1.3 34000 -45.9 -50.6 360 19 10 5.7 3.2 | -45.1 -49.2 020 21 11 6.3 3.5 32000 -42.5 -44.5 345 16 8 5.7 3.2 | -41.3 -42.3 015 20 10 6.3 3.5 30000 -38.6 -37.5 320 14 7 6.8 3.8 | -37.4 -35.3 360 16 8 6.5 3.6 29000 -36.6 -33.9 305 14 7 6.9 3.8 | -35.5 -31.9 345 15 7 6.5 3.6 28000 -34.5 -30.1 290 15 8 6.8 3.7 | -33.5 -28.3 325 14 7 6.4 3.5 27000 -31.5 -24.7 290 16 8 8.7 4.8 | -31.3 -24.3 315 15 7 7.9 4.4 26000 -28.9 -20.0 290 16 8 8.7 4.8 | -28.9 -20.0 305 15 8 7.9 4.4 25000 -26.3 -15.3 290 16 8 8.8 4.8 | -26.5 -15.7 295 17 9 8.0 4.4 24000 -23.9 -11.0 290 16 8 7.5 4.1 | -24.2 -11.6 290 17 9 7.9 4.3 23000 -21.7 -7.1 290 16 8 7.5 4.1 | -21.8 -7.2 285 17 9 7.9 4.3 22000 -19.5 -3.1 290 16 8 7.5 4.1 | -19.5 -3.1 285 17 9 8.0 4.4 21000 -17.4 0.7 290 16 8 7.0 3.8 | -16.8 1.8 285 16 8 7.2 3.9 20000 -15.3 4.5 285 15 8 7.0 3.9 | -14.7 5.5 285 16 8 7.2 4.0 19500 -14.3 6.3 285 15 8 7.0 3.9 | -13.6 7.5 285 16 8 7.2 4.0 19000 -13.2 8.2 285 15 8 7.5 4.1 | -12.6 9.3 285 15 8 7.2 3.9 18500 -12.2 10.0 285 16 8 7.5 4.1 | -11.5 11.3 285 16 8 7.2 4.0 18000 -11.1 12.0 285 16 8 7.8 4.3 | -10.4 13.3 285 16 8 7.6 4.2 17500 -9.8 14.4 285 16 8 8.3 4.6 | -9.3 15.3 285 16 8 7.8 4.3 17000 -8.6 16.5 285 16 8 8.3 4.5 | -8.1 17.4 285 16 8 7.9 4.3 16500 -7.3 18.9 280 16 8 9.0 4.9 | -6.9 19.6 285 15 8 8.6 4.7 16000 -6.0 21.2 280 15 8 8.9 4.9 | -5.7 21.7 280 15 8 8.5 4.7 15500 -4.7 23.5 285 14 7 8.9 4.9 | -4.4 24.1 280 14 7 8.9 4.9 15000 -3.4 25.9 285 13 7 8.9 4.9 | -3.1 26.4 280 14 7 8.9 4.9 14500 -2.1 28.2 285 12 6 9.1 5.0 | -1.8 28.8 280 13 7 9.0 4.9 14000 -0.7 30.7 285 11 6 9.2 5.0 | -0.5 31.1 280 12 6 9.0 4.9 13500 0.7 33.3 290 11 6 9.2 5.0 | 0.9 33.6 280 11 6 9.1 5.0 13000 2.0 35.6 290 10 5 9.0 4.9 | 2.2 36.0 280 11 5 9.2 5.1 12500 3.4 38.1 290 10 5 8.9 4.9 | 3.6 38.5 275 10 5 9.2 5.1 12000 4.7 40.5 290 9 5 8.6 4.7 | 5.0 41.0 275 9 5 9.3 5.1 11500 5.9 42.6 290 8 4 8.6 4.7 | 6.3 43.3 275 9 4 9.2 5.0 11000 7.2 45.0 285 7 4 8.1 4.4 | 7.6 45.7 275 8 4 8.6 4.7 10500 8.4 47.1 280 6 3 7.9 4.3 | 8.9 48.0 270 7 4 7.8 4.3 10250 8.9 48.0 280 6 3 7.3 4.0 | 9.5 49.1 270 7 4 7.5 4.1 10000 9.5 49.1 275 5 3 7.9 4.4 | 10.1 50.2 270 6 3 8.7 4.8 9750 10.1 50.2 270 5 3 8.5 4.7 | 10.7 51.3 265 6 3 8.8 4.9 9500 10.7 51.3 265 4 2 8.1 4.4 | 11.4 52.5 265 5 3 8.4 4.6 9250 11.3 52.3 255 4 2 7.3 4.0 | 12.0 53.6 260 4 2 7.4 4.1 9000 12.3 54.1 230 3 2 6.7 3.7 | 12.5 54.5 255 4 2 7.7 4.2 8750 12.8 55.0 215 3 2 6.1 3.3 | 13.1 55.6 250 3 2 8.5 4.7 8500 13.2 55.8 200 3 2 4.8 2.6 | 13.7 56.7 245 3 1 7.3 4.0 8250 13.6 56.5 185 4 2 5.0 2.7 | 14.2 57.6 230 2 1 5.2 2.8 8000 14.0 57.2 175 4 2 6.5 3.6 | 15.2 59.4 200 2 1 9.7 5.3 7750 14.5 58.1 165 4 2 5.0 2.7 | 15.9 60.6 190 2 1 7.8 4.3 7500 14.8 58.6 160 5 3 2.9 1.6 | 16.3 61.3 175 2 1 5.2 2.9 7250 15.0 59.0 155 6 3 3.7 2.0 | 16.8 62.2 165 2 1 7.0 3.8 7000 15.3 59.5 150 6 3 4.0 2.2 | 17.5 63.5 160 2 1 11.7 6.4 6750 15.5 59.9 145 5 3 1.9 1.0 | 18.4 65.1 160 2 1 11.4 6.3 6500 15.6 60.1 135 5 3 -0.5 -0.3 | 19.1 66.4 155 2 1 9.2 5.0 6250 15.6 60.1 130 6 3 2.1 1.2 | 19.8 67.6 150 2 1 8.9 4.9 6000 15.8 60.4 125 5 3 2.5 1.4 | 20.6 69.1 150 2 1 13.7 7.5 5750 15.8 60.4 110 4 2 -3.7 -2.0 | 22.0 71.6 150 2 1 25.4 13.9 5500 15.6 60.1 095 4 2 2.6 1.4 | 23.5 74.3 140 2 1 4.8 2.6 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 10/09/2024 at 1500 MDT | 10/09/2024 at 1800 MDT | CAPE... +24.8 LI... -0.0 | CAPE... +1.9 LI... +0.4 CINH... -15.9 K Index... +18.4 | CINH... -5.6 K Index... +17.3 | 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 -62.7 -80.9 285 14 7 3.4 1.9 | -63.4 -82.1 290 14 7 2.9 1.6 45000 -57.3 -71.1 310 15 8 3.4 1.9 | -58.5 -73.3 320 16 8 3.7 2.0 40000 -52.1 -61.8 340 17 9 3.3 1.8 | -53.0 -63.4 345 19 10 4.0 2.2 38000 -50.2 -58.4 355 19 10 3.2 1.8 | -50.5 -58.9 360 21 11 4.0 2.2 36000 -48.3 -54.9 010 22 11 3.2 1.7 | -48.1 -54.6 010 23 12 4.0 2.2 34000 -44.7 -48.5 015 23 12 6.6 3.6 | -44.1 -47.4 015 24 12 6.9 3.8 32000 -40.7 -41.3 015 23 12 6.6 3.6 | -40.0 -40.0 015 23 12 6.9 3.8 30000 -36.4 -33.5 015 20 10 7.4 4.1 | -35.6 -32.1 020 21 11 7.6 4.2 29000 -34.2 -29.6 015 18 9 7.4 4.1 | -33.3 -27.9 020 20 10 7.6 4.2 28000 -32.0 -25.6 010 16 8 7.4 4.1 | -31.0 -23.8 020 18 9 7.6 4.2 27000 -29.9 -21.8 360 14 7 6.8 3.7 | -28.9 -20.0 015 15 8 6.9 3.8 26000 -27.9 -18.2 345 12 6 6.8 3.7 | -26.8 -16.2 005 11 6 6.9 3.8 25000 -25.9 -14.6 325 11 6 6.8 3.7 | -24.8 -12.6 345 8 4 6.9 3.8 24000 -23.7 -10.7 310 12 6 7.4 4.1 | -22.8 -9.0 320 8 4 6.5 3.6 23000 -21.5 -6.7 300 13 7 7.4 4.1 | -20.9 -5.6 305 10 5 6.5 3.6 22000 -18.8 -1.8 290 15 8 7.4 4.1 | -18.5 -1.3 290 14 7 6.8 3.7 21000 -16.6 2.1 290 15 8 7.3 4.0 | -16.4 2.5 290 14 7 7.3 4.0 20000 -14.5 5.9 285 16 8 7.3 4.0 | -14.2 6.4 295 15 8 7.4 4.0 19500 -13.4 7.9 285 16 8 7.3 4.0 | -13.2 8.2 295 15 8 7.4 4.0 19000 -12.3 9.9 285 16 8 8.1 4.5 | -12.0 10.4 300 15 7 8.2 4.5 18500 -11.1 12.0 285 15 8 8.1 4.4 | -10.8 12.6 300 14 7 8.1 4.5 18000 -10.0 14.0 285 15 8 8.1 4.4 | -9.6 14.7 300 14 7 8.3 4.6 17500 -8.8 16.2 285 15 7 8.1 4.5 | -8.4 16.9 300 13 7 8.5 4.6 17000 -7.6 18.3 285 14 7 8.2 4.5 | -7.1 19.2 305 13 7 8.5 4.7 16500 -6.3 20.7 285 14 7 8.6 4.7 | -5.8 21.6 300 12 6 8.8 4.9 16000 -5.1 22.8 285 14 7 8.6 4.7 | -4.5 23.9 300 12 6 8.8 4.8 15500 -3.8 25.2 285 13 7 9.0 4.9 | -3.2 26.2 300 11 6 8.8 4.8 15000 -2.5 27.5 285 13 7 9.0 4.9 | -1.9 28.6 295 11 6 8.8 4.8 14500 -1.1 30.0 280 13 6 9.0 5.0 | -0.6 30.9 295 11 5 8.9 4.9 14000 0.2 32.4 280 12 6 9.1 5.0 | 0.7 33.3 295 10 5 9.0 4.9 13500 1.5 34.7 280 12 6 9.1 5.0 | 2.0 35.6 290 10 5 9.0 5.0 13000 2.9 37.2 280 11 6 9.3 5.1 | 3.4 38.1 290 10 5 9.1 5.0 12500 4.3 39.7 280 11 6 9.3 5.1 | 4.7 40.5 290 9 5 9.1 5.0 12000 5.7 42.3 280 11 5 9.3 5.1 | 6.1 43.0 290 9 5 9.3 5.1 11500 7.0 44.6 280 10 5 9.3 5.1 | 7.5 45.5 290 9 5 9.2 5.1 11000 8.4 47.1 280 10 5 9.1 5.0 | 8.9 48.0 290 9 5 9.1 5.0 10500 9.8 49.6 280 9 5 6.2 3.4 | 10.2 50.4 290 9 4 6.7 3.7 10250 10.2 50.4 280 9 5 7.0 3.8 | 10.7 51.3 290 9 5 7.3 4.0 10000 10.9 51.6 280 9 5 11.5 6.3 | 11.4 52.5 290 9 5 11.0 6.0 9750 11.7 53.1 280 9 4 10.4 5.7 | 12.2 54.0 290 9 4 10.1 5.5 9500 12.5 54.5 280 8 4 10.2 5.6 | 12.9 55.2 290 8 4 10.1 5.5 9250 13.2 55.8 280 8 4 8.8 4.9 | 13.6 56.5 290 8 4 9.0 4.9 9000 13.8 56.8 285 8 4 9.3 5.1 | 14.3 57.7 290 8 4 8.9 4.9 8750 14.6 58.3 285 8 4 10.3 5.7 | 15.0 59.0 290 8 4 9.4 5.1 8500 15.3 59.5 285 7 4 9.2 5.0 | 15.7 60.3 290 8 4 8.8 4.8 8250 15.9 60.6 285 7 4 6.9 3.8 | 16.8 62.2 290 8 4 8.4 4.6 8000 17.2 63.0 285 7 4 11.6 6.4 | 17.5 63.5 290 7 4 10.8 5.9 7750 18.0 64.4 285 6 3 9.6 5.3 | 18.3 64.9 290 6 3 9.2 5.1 7500 18.6 65.5 285 6 3 7.1 3.9 | 18.9 66.0 295 6 3 7.1 3.9 7250 19.2 66.6 290 7 3 8.7 4.8 | 19.4 66.9 295 6 3 7.9 4.4 7000 20.0 68.0 290 6 3 12.7 7.0 | 20.1 68.2 295 6 3 10.8 5.9 6750 21.0 69.8 285 6 3 11.8 6.5 | 20.9 69.6 290 5 3 10.8 5.9 6500 21.7 71.1 290 6 3 9.7 5.3 | 21.7 71.1 295 5 3 9.3 5.1 6250 22.4 72.3 290 6 3 9.1 5.0 | 22.4 72.3 300 5 3 9.8 5.4 6000 23.2 73.8 290 6 3 12.9 7.1 | 23.0 73.4 300 5 3 7.2 3.9 5750 24.6 76.3 290 5 3 24.5 13.5 | 23.4 74.1 295 4 2 3.1 1.7 5500 26.2 79.2 295 5 3 11.8 6.5 | 23.8 74.8 305 4 2 12.7 7.0 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