Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
935 UXUS97 KGJT 011307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Monday, July 1, 2024 This forecast is for Monday, July 1, 2024: If the trigger temperature of 82.5 F/28.1 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1082 ft/min (5.5 m/s) Maximum height of thermals.................. 15020 ft MSL (10181 ft AGL) Forecast maximum temperature................... 90.0 F/32.7 C Time of trigger temperature.................... 1100 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................. 10946 ft MSL (6107 ft AGL) Thermal soaring outlook for Tuesday 07/02...... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:52:18 / 20:44:04 MDT Total possible sunshine........... 14 hr 51 min 46 sec (891 min 46 sec) Altitude of sun at 13:18:11 MDT... 73.46 degrees Upper air data from rawinsonde observation taken on 07/01/2024 at 0600 MDT Freezing level.................. 16000 ft MSL (11161 ft AGL) Convective condensation level... 13646 ft MSL (8807 ft AGL) Lifted condensation level....... 14188 ft MSL (9349 ft AGL) Lifted index.................... -2.5 K index......................... +31.8 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 -64.3 -83.7 235 44 22 4.3 2.4 85.5 186.0 31.1 M M 45000 -59.8 -75.6 225 61 31 6.4 3.5 67.6 153.6 22.2 M M 40000 -49.1 -56.4 230 69 36 7.3 4.0 61.7 143.0 19.7 M M 38000 -44.5 -48.1 225 67 34 8.5 4.6 59.8 139.6 18.9 M M 36000 -39.7 -39.5 225 61 31 6.7 3.7 58.2 136.7 18.3 M M 34000 -36.0 -32.8 225 59 31 8.0 4.4 55.2 131.4 16.6 M M 32000 -30.8 -23.4 225 55 28 8.8 4.9 54.4 129.8 16.4 M M 30000 -25.4 -13.7 220 52 27 7.9 4.3 52.8 127.1 15.7 M M 29000 -23.0 -9.4 225 53 27 8.1 4.4 52.0 125.7 15.3 M M 28000 -21.2 -6.2 225 54 28 5.4 3.0 50.7 123.2 14.4 M M 27000 -20.0 -4.0 230 50 26 2.6 1.4 48.4 119.1 12.8 M M 26000 -18.3 -0.9 240 47 24 7.5 4.1 46.9 116.5 11.7 M M 25000 -16.0 3.2 240 42 22 8.1 4.4 46.1 115.0 11.2 M M 24000 -14.1 6.6 240 42 22 5.8 3.2 45.0 112.9 10.4 M M 23000 -13.1 8.4 235 42 22 -5.6 -3.1 42.7 108.9 8.5 M M 22000 -13.4 7.9 220 45 23 5.5 3.0 39.1 102.4 5.4 M M 21000 -10.9 12.4 225 40 21 7.8 4.3 38.7 101.6 5.0 M M 20000 -8.8 16.2 230 39 20 8.3 4.5 37.7 99.9 4.2 M M 19500 -7.6 18.3 230 38 20 9.4 5.2 37.4 99.4 4.0 M M 19000 -6.5 20.3 235 39 20 6.7 3.7 37.1 98.8 3.7 M M 18500 -5.3 22.5 230 37 19 8.3 4.6 36.9 98.4 3.4 M M 18000 -4.1 24.6 230 35 18 7.7 4.2 36.6 97.8 3.2 M M 17500 -3.0 26.6 230 33 17 8.1 4.4 36.3 97.3 2.9 M M 17000 -1.8 28.8 225 31 16 6.4 3.5 36.0 96.8 2.6 M M 16500 -0.8 30.6 230 27 14 6.8 3.7 34.7 94.5 1.4 M M 16000 0.2 32.4 230 30 15 6.7 3.7 34.3 93.7 1.0 M M 15500 1.1 34.0 240 30 16 6.7 3.7 33.7 92.7 0.4 M M 15000 2.0 35.6 245 31 16 6.8 3.7 33.3 91.9 -0.1 872 4.4 14500 2.9 37.2 250 30 16 7.2 3.9 32.8 91.0 -0.7 830 4.2 14000 4.1 39.4 255 31 16 7.7 4.2 32.4 90.4 -1.0 782 4.0 13500 5.2 41.4 255 30 15 7.7 4.2 32.1 89.8 -1.3 733 3.7 13000 6.3 43.3 255 29 15 7.7 4.2 31.8 89.2 -1.6 685 3.5 12500 7.5 45.5 265 25 13 7.7 4.2 31.5 88.7 -2.0 636 3.2 12000 8.6 47.5 260 23 12 7.7 4.2 31.2 88.1 -2.3 587 3.0 11500 9.7 49.5 255 19 10 7.7 4.2 30.8 87.4 -2.6 538 2.7 11000 10.8 51.4 245 16 8 7.7 4.2 30.5 86.9 -3.0 490 2.5 10500 12.0 53.6 240 15 8 8.0 4.4 30.1 86.3 -3.3 441 2.2 10250 12.6 54.7 235 13 7 8.6 4.7 30.0 86.1 -3.5 416 2.1 10000 13.2 55.8 220 11 6 8.7 4.8 30.0 85.9 -3.5 389 2.0 9750 13.8 56.8 220 11 6 8.7 4.8 29.9 85.8 -3.6 363 1.8 9500 14.5 58.1 220 11 6 8.7 4.8 29.8 85.7 -3.7 337 1.7 9250 15.1 59.2 220 12 6 8.7 4.8 29.8 85.6 -3.8 310 1.6 9000 15.7 60.3 215 13 7 8.7 4.8 29.7 85.4 -3.9 284 1.4 8750 16.4 61.5 210 12 6 8.7 4.8 29.6 85.3 -4.0 258 1.3 8500 17.0 62.6 215 13 7 8.7 4.8 29.5 85.2 -4.1 231 1.2 8250 17.6 63.7 215 10 5 8.7 4.8 29.5 85.0 -4.2 205 1.0 8000 18.3 64.9 210 6 3 8.7 4.8 29.4 84.9 -4.3 179 0.9 7750 18.9 66.0 205 8 4 8.7 4.8 29.3 84.7 -4.4 153 0.8 7500 19.5 67.1 205 9 4 8.7 4.8 29.2 84.6 -4.5 126 0.6 7250 20.2 68.4 200 10 5 8.7 4.8 29.1 84.4 -4.6 100 0.5 7000 20.8 69.4 185 12 6 8.7 4.8 29.1 84.3 -4.7 74 0.4 6750 21.4 70.5 180 14 7 8.7 4.8 29.0 84.1 -4.8 47 0.2 6500 22.0 71.6 175 16 8 8.7 4.8 28.9 84.0 -5.0 21 0.1 6250 22.7 72.9 165 18 9 8.7 4.8 28.8 83.8 -5.1 M M 6000 23.3 73.9 160 20 10 8.6 4.7 28.7 83.7 -5.2 M M 5750 23.9 75.0 160 21 11 8.9 4.9 28.6 83.5 -5.3 M M 5500 24.6 76.3 155 22 11 7.9 4.3 28.5 83.4 -5.4 M M 5250 25.1 77.2 155 22 11 6.5 3.6 28.3 83.0 -5.7 M M 5000 25.5 77.9 160 23 12 4.7 2.6 28.0 82.5 -6.0 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 07/01/2024 at 0900 MDT | 07/01/2024 at 1200 MDT | CAPE... +592.7 LI... -4.4 | CAPE... +594.9 LI... -3.4 CINH... -41.9 K Index... +28.2 | CINH... -4.8 K Index... +27.6 | 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 -61.8 -79.2 250 37 19 2.9 1.6 | -62.0 -79.6 255 36 19 3.0 1.6 45000 -56.6 -69.9 240 56 29 4.5 2.5 | -56.6 -69.9 245 55 28 4.8 2.6 40000 -48.8 -55.8 230 69 36 7.2 4.0 | -48.5 -55.3 230 70 36 6.8 3.7 38000 -44.5 -48.1 230 69 35 7.2 3.9 | -44.4 -47.9 230 70 36 6.8 3.7 36000 -40.1 -40.2 230 68 35 7.2 4.0 | -40.3 -40.5 230 70 36 6.9 3.8 34000 -35.8 -32.4 230 66 34 7.3 4.0 | -36.0 -32.8 235 68 35 7.3 4.0 32000 -31.4 -24.5 230 65 33 7.4 4.1 | -31.6 -24.9 235 67 34 7.4 4.1 30000 -27.5 -17.5 230 59 30 6.2 3.4 | -27.9 -18.2 235 61 31 6.0 3.3 29000 -25.6 -14.1 235 56 29 6.2 3.4 | -26.1 -15.0 235 57 29 6.0 3.3 28000 -23.8 -10.8 235 53 27 6.3 3.4 | -24.3 -11.7 240 54 28 6.3 3.5 27000 -21.9 -7.4 235 50 26 6.3 3.5 | -22.3 -8.1 240 51 26 6.7 3.7 26000 -19.5 -3.1 235 47 24 6.3 3.5 | -19.7 -3.5 240 48 25 6.7 3.7 25000 -17.6 0.3 235 44 23 6.3 3.4 | -17.7 0.1 240 45 23 6.8 3.7 24000 -15.8 3.6 235 44 23 6.3 3.4 | -15.7 3.7 240 44 23 6.9 3.8 23000 -14.0 6.8 235 44 22 6.3 3.5 | -13.6 7.5 240 44 23 7.0 3.8 22000 -12.1 10.2 235 43 22 5.6 3.1 | -11.5 11.3 240 43 22 5.9 3.2 21000 -10.8 12.6 235 41 21 5.0 2.7 | -10.1 13.8 240 42 22 5.0 2.7 20000 -9.4 15.1 235 38 20 5.1 2.8 | -8.7 16.3 240 41 21 5.2 2.8 19500 -8.7 16.3 235 37 19 5.3 2.9 | -8.0 17.6 240 40 21 5.3 2.9 19000 -7.7 18.1 235 36 18 7.7 4.2 | -7.3 18.9 240 39 20 5.8 3.2 18500 -6.7 19.9 235 35 18 7.5 4.1 | -6.5 20.3 240 39 20 5.9 3.2 18000 -5.6 21.9 240 34 17 7.4 4.1 | -5.7 21.7 245 38 19 6.4 3.5 17500 -4.5 23.9 240 33 17 7.4 4.1 | -4.8 23.4 245 37 19 6.7 3.7 17000 -3.5 25.7 240 32 16 7.4 4.0 | -3.8 25.2 245 36 18 6.8 3.7 16500 -2.4 27.7 240 31 16 6.8 3.7 | -2.8 27.0 250 34 18 6.7 3.7 16000 -1.4 29.5 240 30 16 6.8 3.7 | -1.8 28.8 250 32 17 6.7 3.7 15500 -0.3 31.5 240 29 15 7.9 4.4 | -0.8 30.6 250 31 16 7.2 3.9 15000 0.9 33.6 240 29 15 8.1 4.4 | 0.3 32.5 250 29 15 7.3 4.0 14500 2.1 35.8 245 28 14 8.5 4.7 | 1.4 34.5 250 27 14 7.8 4.3 14000 3.5 38.3 245 26 14 8.8 4.8 | 2.7 36.9 250 25 13 8.3 4.6 13500 4.9 40.8 245 25 13 8.7 4.7 | 3.9 39.0 250 24 12 8.4 4.6 13000 6.1 43.0 245 24 13 8.2 4.5 | 5.2 41.4 250 23 12 8.7 4.8 12500 7.3 45.1 250 24 12 8.1 4.4 | 6.5 43.7 250 22 11 8.7 4.8 12000 8.4 47.1 250 23 12 7.3 4.0 | 7.8 46.0 245 21 11 8.9 4.9 11500 9.4 48.9 245 21 11 7.4 4.1 | 9.1 48.4 245 20 10 8.9 4.9 11000 10.4 50.7 245 21 11 7.4 4.1 | 10.3 50.5 245 19 10 8.1 4.5 10500 11.4 52.5 245 20 10 5.8 3.2 | 11.4 52.5 240 18 9 9.2 5.0 10250 11.8 53.2 245 20 10 6.1 3.3 | 12.1 53.8 240 18 9 9.6 5.2 10000 12.3 54.1 245 19 10 8.6 4.7 | 12.7 54.9 240 17 9 8.6 4.7 9750 12.9 55.2 245 18 9 7.9 4.3 | 13.3 55.9 235 16 8 8.9 4.9 9500 13.4 56.1 240 17 9 8.2 4.5 | 13.8 56.8 235 16 8 9.0 4.9 9250 14.0 57.2 240 17 9 8.6 4.7 | 14.5 58.1 235 15 8 9.7 5.3 9000 15.0 59.0 235 15 8 6.6 3.6 | 15.8 60.4 230 14 7 8.5 4.7 8750 15.5 59.9 230 14 7 7.0 3.9 | 16.4 61.5 230 14 7 8.8 4.8 8500 16.0 60.8 230 14 7 7.8 4.3 | 17.0 62.6 230 13 7 8.9 4.9 8250 16.6 61.9 225 13 7 7.7 4.2 | 17.7 63.9 230 13 7 9.7 5.3 8000 17.1 62.8 220 13 7 7.3 4.0 | 18.5 65.3 230 13 7 10.5 5.8 7750 17.6 63.7 215 13 7 6.8 3.7 | 19.2 66.6 230 13 6 9.9 5.4 7500 18.0 64.4 210 12 6 5.9 3.2 | 19.9 67.8 230 12 6 8.5 4.7 7250 18.5 65.3 205 11 6 6.4 3.5 | 20.5 68.9 230 12 6 8.8 4.8 7000 19.0 66.2 195 10 5 9.8 5.4 | 21.3 70.3 230 12 6 11.3 6.2 6750 19.8 67.6 190 10 5 10.1 5.5 | 22.1 71.8 230 11 6 11.5 6.3 6500 20.4 68.7 185 9 5 8.5 4.7 | 22.9 73.2 230 11 6 10.6 5.8 6250 21.1 70.0 175 9 5 8.6 4.7 | 23.7 74.7 230 11 5 10.3 5.6 6000 21.7 71.1 170 8 4 9.8 5.4 | 24.5 76.1 230 10 5 10.6 5.8 5750 22.6 72.7 175 8 4 14.6 8.0 | 25.4 77.7 230 9 5 18.0 9.9 5500 23.6 74.5 165 7 3 13.3 7.3 | 27.4 81.3 235 9 4 36.6 20.1 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 07/01/2024 at 1500 MDT | 07/01/2024 at 1800 MDT | CAPE... +286.6 LI... -2.8 | CAPE... +186.0 LI... -2.7 CINH... -4.4 K Index... +26.5 | CINH... -16.3 K Index... +25.6 | 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 -62.3 -80.1 260 34 17 3.2 1.7 | -62.2 -80.0 265 35 18 2.9 1.6 45000 -56.7 -70.1 255 42 22 4.8 2.6 | -56.7 -70.1 255 40 21 5.0 2.7 40000 -48.6 -55.5 240 49 25 6.9 3.8 | -48.4 -55.1 245 42 22 6.8 3.7 38000 -44.5 -48.1 240 50 26 6.9 3.8 | -44.3 -47.7 245 43 22 6.8 3.7 36000 -40.4 -40.7 240 52 27 7.0 3.8 | -40.2 -40.4 245 43 22 6.8 3.7 34000 -36.1 -33.0 240 50 26 7.2 3.9 | -36.1 -33.0 245 44 23 6.9 3.8 32000 -31.8 -25.2 240 48 25 7.2 3.9 | -31.9 -25.4 245 44 23 6.9 3.8 30000 -27.6 -17.7 245 47 24 6.8 3.7 | -27.8 -18.0 250 44 22 6.9 3.8 29000 -25.6 -14.1 245 47 24 6.8 3.7 | -25.7 -14.3 250 43 22 7.7 3.8 28000 -23.6 -10.5 245 46 24 6.8 3.7 | -23.6 -10.5 250 43 22 7.1 3.9 27000 -21.6 -6.9 250 46 24 6.7 3.7 | -21.4 -6.5 255 43 22 7.3 4.0 26000 -19.5 -3.1 250 47 24 6.7 3.7 | -18.7 -1.7 255 43 22 7.2 4.0 25000 -17.0 1.4 250 47 24 6.5 3.6 | -16.5 2.3 255 43 22 6.5 3.6 24000 -15.1 4.8 250 45 23 6.3 3.5 | -14.9 5.2 255 41 21 5.4 3.0 23000 -13.3 8.1 250 44 23 6.3 3.5 | -13.3 8.1 260 40 21 5.4 3.0 22000 -11.4 11.5 250 42 22 5.2 2.8 | -11.7 10.9 260 39 20 4.8 2.6 21000 -10.2 13.6 250 40 21 4.1 2.2 | -10.6 12.9 260 36 19 4.0 2.2 20000 -9.1 15.6 250 37 19 4.2 2.3 | -9.5 14.9 260 34 17 4.2 2.3 19500 -8.5 16.7 255 36 18 4.3 2.4 | -9.0 15.8 260 32 17 4.1 2.3 19000 -7.7 18.1 255 35 18 7.3 4.0 | -8.1 17.4 260 31 16 8.5 4.7 18500 -6.7 19.9 255 35 18 7.1 3.9 | -6.9 19.6 260 30 15 8.1 4.5 18000 -5.7 21.7 255 34 18 7.4 4.1 | -5.7 21.7 260 28 15 8.5 4.7 17500 -4.6 23.7 250 34 17 7.6 4.2 | -4.4 24.1 260 27 14 8.9 4.9 17000 -3.5 25.7 250 33 17 7.7 4.2 | -3.2 26.2 260 26 14 8.9 4.9 16500 -2.3 27.9 250 32 17 8.3 4.6 | -1.8 28.8 255 26 13 9.4 5.2 16000 -1.1 30.0 250 32 16 8.3 4.5 | -0.4 31.3 255 25 13 9.4 5.2 15500 0.1 32.2 250 31 16 8.6 4.7 | 0.9 33.6 255 25 13 9.3 5.1 15000 1.3 34.3 250 30 15 8.7 4.8 | 2.3 36.1 255 24 13 9.3 5.1 14500 2.6 36.7 250 29 15 8.8 4.8 | 3.7 38.7 255 24 12 9.4 5.1 14000 3.9 39.0 250 27 14 8.8 4.8 | 5.1 41.2 250 23 12 9.4 5.2 13500 5.2 41.4 250 26 14 8.9 4.9 | 6.5 43.7 250 23 12 9.4 5.2 13000 6.5 43.7 250 25 13 9.2 5.0 | 7.8 46.0 250 22 11 9.4 5.2 12500 7.8 46.0 250 24 12 9.2 5.0 | 9.2 48.6 245 22 11 9.4 5.2 12000 9.2 48.6 245 23 12 9.1 5.0 | 10.6 51.1 245 21 11 9.3 5.1 11500 10.5 50.9 245 22 11 9.2 5.1 | 12.0 53.6 245 20 11 9.5 5.2 11000 11.8 53.2 245 20 10 8.3 4.6 | 13.3 55.9 245 20 10 7.8 4.3 10500 13.0 55.4 240 19 10 10.0 5.5 | 14.4 57.9 245 19 10 10.4 5.7 10250 13.8 56.8 240 18 10 10.8 5.9 | 15.4 59.7 240 19 10 12.4 6.8 10000 14.5 58.1 240 18 9 9.2 5.1 | 16.1 61.0 240 18 9 9.5 5.2 9750 15.2 59.4 235 18 9 9.7 5.3 | 16.8 62.2 240 18 9 9.0 4.9 9500 15.9 60.6 235 17 9 9.5 5.2 | 17.5 63.5 235 17 9 9.4 5.2 9250 16.6 61.9 235 17 9 9.7 5.3 | 18.2 64.8 235 17 9 8.3 4.5 9000 17.4 63.3 235 17 9 9.8 5.4 | 19.5 67.1 235 16 8 10.0 5.5 8750 18.8 65.8 235 16 8 9.8 5.4 | 20.2 68.4 235 16 8 9.7 5.3 8500 19.5 67.1 235 16 8 8.9 4.9 | 20.9 69.6 235 15 8 9.6 5.3 8250 20.2 68.4 235 16 8 9.5 5.2 | 21.6 70.9 235 16 8 9.7 5.3 8000 20.9 69.6 235 15 8 10.8 5.9 | 22.4 72.3 235 15 8 10.0 5.5 7750 21.7 71.1 230 14 7 10.1 5.6 | 23.1 73.6 230 15 8 10.0 5.5 7500 22.4 72.3 230 14 7 8.4 4.6 | 23.8 74.8 230 15 7 9.1 5.0 7250 23.0 73.4 230 14 7 8.5 4.6 | 24.5 76.1 230 15 8 8.9 4.9 7000 23.7 74.7 230 14 7 11.1 6.1 | 25.2 77.4 230 15 8 10.2 5.6 6750 24.6 76.3 230 13 7 11.5 6.3 | 26.0 78.8 230 14 7 10.6 5.8 6500 25.4 77.7 230 13 7 10.9 6.0 | 26.7 80.1 230 13 7 10.6 5.8 6250 26.2 79.2 230 13 6 10.9 6.0 | 27.6 81.7 230 14 7 11.0 6.0 6000 27.0 80.6 230 12 6 9.4 5.1 | 28.3 82.9 230 13 7 7.9 4.3 5750 27.8 82.0 225 11 6 15.8 8.7 | 28.8 83.8 230 12 6 8.8 4.8 5500 30.3 86.5 225 10 5 64.1 35.2 | 30.7 87.3 230 11 6 55.3 30.4 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