Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
060 UXUS97 KGJT 061307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Saturday, July 6, 2024 This forecast is for Saturday, July 6, 2024: If the trigger temperature of 81.2 F/27.3 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1152 ft/min (5.9 m/s) Maximum height of thermals.................. 18043 ft MSL (13204 ft AGL) Forecast maximum temperature................... 95.0 F/35.5 C Time of trigger temperature.................... 1045 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................. 15813 ft MSL (10974 ft AGL) Thermal soaring outlook for Sunday 07/07....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:55:04 / 20:43:03 MDT Total possible sunshine........... 14 hr 47 min 59 sec (887 min 59 sec) Altitude of sun at 13:19:04 MDT... 72.97 degrees Upper air data from rawinsonde observation taken on 07/06/2024 at 0600 MDT Freezing level.................. 15103 ft MSL (10264 ft AGL) Convective condensation level... 22141 ft MSL (17302 ft AGL) Lifted condensation level....... 20841 ft MSL (16002 ft AGL) Lifted index.................... +2.0 K index......................... +7.8 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 -59.9 -75.8 305 41 21 5.4 3.0 95.0 202.9 34.7 M M 45000 -58.1 -72.6 300 51 26 6.4 3.5 72.3 162.1 23.2 M M 40000 -49.6 -57.3 310 47 24 4.7 2.6 62.9 145.2 18.6 M M 38000 -46.8 -52.2 315 45 23 4.6 2.5 58.3 137.0 15.9 M M 36000 -43.9 -47.0 310 44 23 5.3 2.9 54.0 129.2 13.3 M M 34000 -41.0 -41.8 320 41 21 4.8 2.6 49.9 121.8 10.7 M M 32000 -36.8 -34.2 310 39 20 8.6 4.7 46.5 115.8 8.5 M M 30000 -32.1 -25.8 320 33 17 7.5 4.1 45.0 113.1 7.6 M M 29000 -29.7 -21.5 325 32 16 8.0 4.4 44.3 111.7 7.1 M M 28000 -27.3 -17.1 330 35 18 8.0 4.4 43.6 110.5 6.7 M M 27000 -25.3 -13.5 325 29 15 6.4 3.5 42.4 108.4 5.8 M M 26000 -23.4 -10.1 325 30 15 7.6 4.2 41.2 106.1 4.9 M M 25000 -20.9 -5.6 330 33 17 8.7 4.8 40.7 105.2 4.5 M M 24000 -18.2 -0.8 335 33 17 9.0 4.9 40.4 104.7 4.4 M M 23000 -15.6 3.9 320 29 15 8.4 4.6 40.0 104.0 4.1 M M 22000 -13.1 8.4 325 30 16 8.4 4.6 39.5 103.2 3.8 M M 21000 -10.6 12.9 320 29 15 8.5 4.7 39.1 102.3 3.4 M M 20000 -8.6 16.5 315 26 14 0.1 0.1 37.9 100.2 2.4 M M 19500 -8.0 17.6 305 29 15 5.9 3.3 36.8 98.3 1.5 M M 19000 -7.0 19.4 310 29 15 7.2 3.9 36.4 97.5 1.2 M M 18500 -6.0 21.2 305 27 14 6.2 3.4 35.8 96.4 0.6 M M 18000 -4.7 23.5 300 25 13 6.1 3.4 34.8 94.7 -0.2 1138 5.8 17500 -3.8 25.2 295 23 12 6.1 3.3 34.2 93.5 -0.7 1096 5.6 17000 -2.9 26.8 285 22 11 6.1 3.3 33.6 92.4 -1.3 1054 5.4 16500 -2.4 27.7 270 19 10 3.9 2.2 32.5 90.5 -2.3 1025 5.2 16000 -1.5 29.3 260 18 9 6.3 3.5 32.0 89.5 -2.9 983 5.0 15500 -0.6 30.9 260 16 8 6.7 3.7 31.4 88.6 -3.5 941 4.8 15000 0.3 32.5 255 13 7 7.1 3.9 30.9 87.7 -4.0 899 4.6 14500 1.5 34.7 260 12 6 8.5 4.7 30.6 87.2 -4.4 850 4.3 14000 2.7 36.9 265 10 5 8.5 4.6 30.5 86.8 -4.6 797 4.1 13500 4.0 39.2 265 10 5 8.5 4.6 30.3 86.5 -4.8 745 3.8 13000 5.3 41.5 270 10 5 8.5 4.6 30.1 86.1 -5.0 692 3.5 12500 6.5 43.7 270 9 5 8.5 4.6 29.9 85.7 -5.2 640 3.2 12000 7.8 46.0 250 7 4 8.5 4.6 29.6 85.4 -5.4 587 3.0 11500 9.0 48.2 245 6 3 8.4 4.6 29.4 85.0 -5.7 535 2.7 11000 10.3 50.5 245 2 1 8.4 4.6 29.2 84.6 -5.9 482 2.4 10500 11.6 52.9 105 5 2 7.3 4.0 29.0 84.1 -6.2 429 2.2 10250 12.0 53.6 090 6 3 5.1 2.8 28.7 83.6 -6.5 409 2.1 10000 12.4 54.3 070 7 4 7.2 3.9 28.3 83.0 -6.8 389 2.0 9750 13.0 55.4 065 6 3 8.7 4.8 28.2 82.8 -6.9 363 1.8 9500 13.7 56.7 070 6 3 8.3 4.5 28.1 82.7 -7.0 337 1.7 9250 14.3 57.7 080 5 3 8.4 4.6 28.0 82.5 -7.2 311 1.6 9000 14.9 58.8 080 8 4 8.4 4.6 27.9 82.3 -7.3 285 1.4 8750 15.5 59.9 075 7 4 8.4 4.6 27.8 82.1 -7.4 259 1.3 8500 16.2 61.2 070 6 3 8.4 4.6 27.7 81.9 -7.5 232 1.2 8250 16.8 62.2 055 5 2 8.4 4.6 27.6 81.7 -7.7 206 1.0 8000 17.4 63.3 045 4 2 8.4 4.6 27.5 81.5 -7.8 180 0.9 7750 18.0 64.4 060 4 2 8.4 4.6 27.4 81.3 -7.9 154 0.8 7500 18.6 65.5 070 4 2 8.4 4.6 27.3 81.1 -8.0 128 0.7 7250 19.3 66.7 080 4 2 8.1 4.4 27.2 80.9 -8.2 102 0.5 7000 19.9 67.8 075 4 2 9.4 5.2 27.1 80.7 -8.3 76 0.4 6750 20.5 68.9 090 5 3 4.0 2.2 26.9 80.5 -8.5 51 0.3 6500 20.4 68.7 100 8 4 -2.7 -1.5 26.1 79.1 -9.3 45 0.2 6250 20.2 68.4 095 9 4 -3.2 -1.8 25.2 77.4 -10.2 44 0.2 6000 20.0 68.0 095 9 5 -0.4 -0.2 24.3 75.7 -11.2 42 0.2 5750 20.2 68.4 110 10 5 3.5 1.9 23.7 74.6 -11.8 31 0.2 5500 20.4 68.7 125 12 6 2.8 1.6 23.2 73.7 -12.4 18 0.1 5250 20.4 68.7 130 15 7 -1.5 -0.8 22.5 72.6 -13.1 9 0.0 5000 19.8 67.6 120 16 8 -15.6 -8.6 21.2 70.2 -14.5 20 0.1 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 07/06/2024 at 0900 MDT | 07/06/2024 at 1200 MDT | CAPE... 0.0 LI... +7.2 | CAPE... 0.0 LI... +5.9 CINH... -0.1 K Index... -8.0 | CINH... 0.0 K Index... -2.1 | 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 -59.9 -75.8 305 36 18 1.3 0.7 | -59.8 -75.6 300 35 18 1.9 1.1 45000 -56.4 -69.5 305 52 27 4.1 2.3 | -56.1 -69.0 305 55 28 3.3 1.8 40000 -50.2 -58.4 315 56 29 4.0 2.2 | -51.0 -59.8 310 63 32 4.1 2.2 38000 -47.8 -54.0 320 55 28 4.0 2.2 | -48.5 -55.3 315 59 30 4.1 2.3 36000 -45.4 -49.7 325 55 28 3.8 2.1 | -46.0 -50.8 315 56 29 4.0 2.2 34000 -41.7 -43.1 325 50 26 6.7 3.6 | -42.2 -44.0 315 50 26 6.9 3.8 32000 -37.7 -35.9 325 44 23 6.6 3.6 | -38.0 -36.4 320 45 23 6.9 3.8 30000 -33.2 -27.8 325 41 21 7.8 4.3 | -33.3 -27.9 315 41 21 8.3 4.5 29000 -30.8 -23.4 320 40 21 7.8 4.3 | -30.8 -23.4 315 40 21 8.3 4.5 28000 -28.5 -19.3 320 39 20 8.0 4.4 | -28.3 -18.9 310 38 20 8.3 4.6 27000 -25.3 -13.5 320 38 19 8.6 4.7 | -25.1 -13.2 310 38 19 8.5 4.7 26000 -22.7 -8.9 315 37 19 8.6 4.7 | -22.6 -8.7 310 37 19 8.5 4.7 25000 -20.1 -4.2 315 36 18 8.4 4.6 | -20.0 -4.0 310 36 19 8.4 4.6 24000 -17.7 0.1 310 34 17 8.1 4.5 | -17.6 0.3 315 35 18 8.2 4.5 23000 -15.2 4.6 310 32 16 8.1 4.5 | -15.1 4.8 315 35 18 8.2 4.5 22000 -12.8 9.0 305 30 15 7.8 4.3 | -12.7 9.1 315 34 18 7.4 4.1 21000 -10.6 12.9 305 28 15 7.3 4.0 | -10.7 12.7 315 32 17 6.5 3.6 20000 -8.4 16.9 305 27 14 7.3 4.0 | -8.7 16.3 315 30 16 6.5 3.6 19500 -7.3 18.9 305 26 14 7.4 4.1 | -7.8 18.0 315 29 15 6.5 3.6 19000 -6.2 20.8 305 26 13 6.2 3.4 | -6.9 19.6 315 28 15 5.6 3.1 18500 -5.3 22.5 305 25 13 6.3 3.4 | -6.0 21.2 315 27 14 5.7 3.1 18000 -4.4 24.1 305 24 13 6.0 3.3 | -5.2 22.6 310 26 13 5.8 3.2 17500 -3.5 25.7 305 23 12 5.8 3.2 | -4.3 24.3 310 25 13 5.9 3.2 17000 -2.6 27.3 305 22 11 5.8 3.2 | -3.4 25.9 310 24 12 5.9 3.2 16500 -1.9 28.6 305 21 11 4.8 2.6 | -2.6 27.3 310 22 12 6.1 3.4 16000 -1.1 30.0 305 19 10 4.9 2.7 | -1.7 28.9 310 21 11 6.1 3.4 15500 -0.4 31.3 300 18 9 5.2 2.9 | -0.8 30.6 305 20 10 6.0 3.3 15000 0.4 32.7 300 16 8 5.4 3.0 | 0.1 32.2 305 18 10 6.0 3.3 14500 1.2 34.2 300 14 7 5.9 3.3 | 0.9 33.6 305 17 9 6.4 3.5 14000 2.1 35.8 295 13 7 6.6 3.6 | 1.9 35.4 300 16 8 6.9 3.8 13500 3.0 37.4 290 12 6 7.0 3.8 | 2.9 37.2 300 15 7 7.3 4.0 13000 4.1 39.4 290 10 5 8.0 4.4 | 4.1 39.4 300 14 7 8.5 4.6 12500 5.3 41.5 285 9 5 8.0 4.4 | 5.4 41.7 295 13 7 8.5 4.6 12000 6.5 43.7 285 8 4 8.1 4.4 | 6.6 43.9 295 12 6 8.9 4.9 11500 7.7 45.9 290 6 3 8.1 4.4 | 7.9 46.2 295 11 6 8.9 4.9 11000 8.9 48.0 300 5 3 8.3 4.6 | 9.3 48.7 295 10 5 9.0 4.9 10500 10.1 50.2 310 4 2 7.4 4.1 | 10.6 51.1 290 10 5 6.1 3.3 10250 10.6 51.1 320 4 2 6.3 3.5 | 11.0 51.8 295 9 5 6.9 3.8 10000 11.1 52.0 330 3 2 8.3 4.6 | 11.8 53.2 290 9 5 11.5 6.3 9750 11.8 53.2 335 3 2 9.4 5.2 | 12.6 54.7 290 9 4 10.3 5.7 9500 12.5 54.5 335 3 2 9.0 4.9 | 13.3 55.9 290 8 4 10.4 5.7 9250 13.1 55.6 340 3 2 7.8 4.3 | 14.1 57.4 290 8 4 8.8 4.9 9000 14.2 57.6 350 3 1 7.9 4.4 | 14.7 58.5 290 8 4 9.1 5.0 8750 14.8 58.6 345 2 1 7.2 4.0 | 16.2 61.2 285 7 4 9.5 5.2 8500 15.3 59.5 345 2 1 5.3 2.9 | 16.8 62.2 285 7 4 6.9 3.8 8250 15.6 60.1 345 2 1 5.2 2.9 | 17.3 63.1 285 7 4 8.3 4.6 8000 16.1 61.0 340 1 1 7.2 3.9 | 18.1 64.6 285 7 3 12.0 6.6 7750 16.6 61.9 330 1 1 5.7 3.2 | 19.0 66.2 280 6 3 10.2 5.6 7500 16.9 62.4 325 1 0 3.3 1.8 | 19.6 67.3 285 6 3 7.5 4.1 7250 17.2 63.0 000 0 0 3.8 2.1 | 20.2 68.4 285 6 3 8.3 4.6 7000 17.6 63.7 000 0 0 8.4 4.6 | 20.9 69.6 285 6 3 12.5 6.9 6750 18.3 64.9 000 0 0 8.5 4.7 | 21.9 71.4 280 6 3 12.0 6.6 6500 18.8 65.8 135 1 0 6.0 3.3 | 22.7 72.9 280 6 3 10.0 5.5 6250 19.2 66.6 130 1 0 5.9 3.2 | 23.5 74.3 280 6 3 9.4 5.1 6000 19.7 67.5 130 1 1 10.4 5.7 | 24.2 75.6 280 5 3 13.7 7.5 5750 20.9 69.6 135 1 1 21.2 11.6 | 25.7 78.3 280 5 3 28.2 15.5 5500 22.2 72.0 135 1 1 3.9 2.2 | 27.9 82.2 285 5 3 21.5 11.8 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 07/06/2024 at 1500 MDT | 07/06/2024 at 1800 MDT | CAPE... 0.0 LI... +4.1 | CAPE... 0.0 LI... +1.0 CINH... -0.2 K Index... +5.3 | CINH... -0.0 K Index... +8.0 | 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 -60.1 -76.2 300 36 19 2.4 1.3 | -59.6 -75.3 295 38 20 2.1 1.1 45000 -56.1 -69.0 305 55 28 2.9 1.6 | -55.9 -68.6 305 54 28 3.0 1.6 40000 -51.5 -60.7 305 61 31 4.6 2.5 | -51.2 -60.2 305 61 31 4.5 2.5 38000 -48.7 -55.7 310 58 30 4.7 2.6 | -48.4 -55.1 310 60 31 4.6 2.5 36000 -45.8 -50.4 310 56 29 4.6 2.5 | -45.7 -50.3 310 60 31 4.5 2.5 34000 -42.2 -44.0 315 54 28 6.4 3.5 | -42.0 -43.6 315 59 30 6.5 3.6 32000 -38.3 -36.9 320 52 27 6.4 3.5 | -38.0 -36.4 315 57 30 6.5 3.5 30000 -33.5 -28.3 320 49 25 8.4 4.6 | -33.5 -28.3 315 55 28 8.0 4.4 29000 -31.0 -23.8 325 48 25 8.4 4.6 | -31.0 -23.8 315 53 28 8.0 4.4 28000 -28.5 -19.3 325 46 24 8.5 4.7 | -28.6 -19.5 315 52 27 8.1 4.5 27000 -25.2 -13.4 320 43 22 8.7 4.8 | -25.5 -13.9 315 49 25 8.2 4.5 26000 -22.6 -8.7 320 41 21 8.7 4.8 | -23.0 -9.4 315 47 24 8.3 4.5 25000 -20.0 -4.0 320 40 20 8.4 4.6 | -20.6 -5.1 320 45 23 7.9 4.3 24000 -17.6 0.3 320 40 20 8.0 4.4 | -18.4 -1.1 315 44 22 7.1 3.9 23000 -15.2 4.6 315 40 21 8.0 4.4 | -16.3 2.7 315 42 22 7.1 3.9 22000 -12.8 9.0 315 40 21 7.2 3.9 | -14.2 6.4 315 40 21 6.9 3.8 21000 -10.9 12.4 320 39 20 6.5 3.6 | -12.2 10.0 310 37 19 6.7 3.7 20000 -8.9 16.0 320 38 20 6.5 3.5 | -10.2 13.6 310 34 18 6.7 3.7 19500 -8.0 17.6 320 37 19 6.5 3.5 | -9.3 15.3 310 33 17 6.8 3.7 19000 -7.1 19.2 320 36 19 5.4 3.0 | -8.2 17.2 305 31 16 8.1 4.5 18500 -6.3 20.7 320 34 17 5.5 3.0 | -7.0 19.4 305 30 16 8.0 4.4 18000 -5.5 22.1 320 32 16 5.9 3.3 | -5.7 21.7 305 29 15 8.7 4.7 17500 -4.6 23.7 320 29 15 6.2 3.4 | -4.4 24.1 305 28 14 9.0 4.9 17000 -3.7 25.3 320 27 14 6.3 3.5 | -3.1 26.4 300 27 14 9.0 5.0 16500 -2.6 27.3 315 25 13 7.7 4.2 | -1.7 28.9 300 26 14 9.2 5.1 16000 -1.5 29.3 315 23 12 7.6 4.2 | -0.4 31.3 300 25 13 9.2 5.0 15500 -0.4 31.3 310 22 11 8.2 4.5 | 1.0 33.8 300 24 12 9.4 5.2 15000 0.9 33.6 310 21 11 8.3 4.6 | 2.4 36.3 295 23 12 9.4 5.2 14500 2.1 35.8 305 19 10 8.7 4.8 | 3.8 38.8 295 22 11 9.4 5.2 14000 3.4 38.1 305 19 10 9.0 4.9 | 5.2 41.4 295 21 11 9.4 5.2 13500 4.7 40.5 300 18 9 9.1 5.0 | 6.6 43.9 290 20 11 9.4 5.2 13000 6.1 43.0 300 17 9 9.2 5.0 | 8.0 46.4 290 20 10 9.5 5.2 12500 7.4 45.3 295 17 9 9.2 5.0 | 9.4 48.9 290 19 10 9.5 5.2 12000 8.8 47.8 295 16 8 9.3 5.1 | 10.9 51.6 285 18 9 9.6 5.3 11500 10.2 50.4 290 16 8 9.3 5.1 | 12.3 54.1 285 18 9 9.7 5.3 11000 11.5 52.7 290 15 8 8.4 4.6 | 13.6 56.5 280 17 9 7.9 4.3 10500 12.7 54.9 285 14 7 11.3 6.2 | 14.7 58.5 275 16 8 11.5 6.3 10250 13.7 56.7 285 14 7 11.9 6.5 | 15.8 60.4 275 16 8 12.6 6.9 10000 14.4 57.9 280 14 7 8.6 4.7 | 16.5 61.7 275 16 8 8.6 4.7 9750 15.1 59.2 280 13 7 9.5 5.2 | 17.2 63.0 275 16 8 9.7 5.3 9500 15.8 60.4 280 13 7 9.2 5.0 | 17.9 64.2 275 15 8 9.4 5.2 9250 16.5 61.7 280 13 6 9.1 5.0 | 19.2 66.6 270 14 7 9.0 5.0 9000 17.9 64.2 275 12 6 10.0 5.5 | 20.0 68.0 270 14 7 10.0 5.5 8750 18.7 65.7 275 12 6 9.7 5.3 | 20.7 69.3 270 14 7 9.8 5.4 8500 19.3 66.7 275 11 6 7.8 4.3 | 21.4 70.5 270 13 7 8.7 4.8 8250 19.9 67.8 275 11 6 9.2 5.0 | 22.1 71.8 265 13 7 9.1 5.0 8000 20.7 69.3 275 11 6 11.9 6.5 | 22.8 73.0 265 13 6 10.5 5.8 7750 21.6 70.9 275 11 6 10.3 5.6 | 23.6 74.5 265 12 6 10.0 5.5 7500 22.3 72.1 275 11 5 7.9 4.3 | 24.3 75.7 265 12 6 9.0 4.9 7250 22.9 73.2 275 11 5 8.5 4.7 | 24.9 76.8 265 12 6 9.1 5.0 7000 23.6 74.5 275 10 5 12.7 7.0 | 25.7 78.3 265 12 6 10.6 5.8 6750 24.6 76.3 270 10 5 12.2 6.7 | 26.5 79.7 265 11 6 10.9 6.0 6500 25.4 77.7 270 10 5 10.1 5.6 | 27.3 81.1 265 11 6 10.6 5.8 6250 26.2 79.2 275 10 5 9.8 5.4 | 28.1 82.6 260 11 6 10.7 5.8 6000 27.0 80.6 275 9 5 12.7 7.0 | 28.8 83.8 260 10 5 8.5 4.7 5750 28.3 82.9 270 9 4 26.0 14.3 | 29.5 85.1 265 10 5 11.6 6.4 5500 30.8 87.4 275 8 4 36.5 20.0 | 31.5 88.7 260 9 5 51.9 28.5 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