Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
581 UXUS97 KGJT 311307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Friday, May 31, 2024 This forecast is for Friday, May 31, 2024: If the trigger temperature of 72.8 F/22.7 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1084 ft/min (5.5 m/s) Maximum height of thermals.................. 19052 ft MSL (14213 ft AGL) Forecast maximum temperature................... 86.0 F/30.5 C Time of trigger temperature.................... 0945 MDT Time of overdevelopment........................ 2000 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................. 15962 ft MSL (11123 ft AGL) Thermal soaring outlook for Saturday 06/01..... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:50:03 / 20:33:52 MDT Total possible sunshine........... 14 hr 43 min 49 sec (883 min 49 sec) Altitude of sun at 13:11:58 MDT... 72.76 degrees Upper air data from rawinsonde observation taken on 05/31/2024 at 0600 MDT Freezing level.................. 13313 ft MSL (8474 ft AGL) Convective condensation level... 19516 ft MSL (14677 ft AGL) Lifted condensation level....... 19607 ft MSL (14768 ft AGL) Lifted index.................... +0.1 K index......................... +5.6 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 -57.3 -71.1 270 37 19 0.6 0.3 103.8 218.9 42.3 M M 45000 -59.4 -74.9 255 31 16 2.1 1.1 74.6 166.2 27.4 M M 40000 -58.8 -73.8 275 46 24 2.8 1.5 52.4 126.3 14.7 M M 38000 -56.2 -69.2 265 45 23 4.9 2.7 47.5 117.6 11.9 M M 36000 -53.2 -63.8 270 47 24 6.2 3.4 43.4 110.1 9.3 M M 34000 -49.1 -56.4 270 43 22 7.9 4.3 40.9 105.7 7.8 M M 32000 -43.7 -46.7 270 40 21 7.3 4.0 39.2 102.6 6.8 M M 30000 -38.7 -37.7 260 38 20 9.6 5.3 38.1 100.6 6.1 M M 29000 -36.0 -32.8 255 38 20 7.7 4.2 37.8 100.0 5.9 M M 28000 -33.3 -27.9 255 39 20 7.8 4.3 37.5 99.6 5.8 M M 27000 -30.9 -23.6 260 37 19 8.4 4.6 37.0 98.6 5.4 M M 26000 -28.4 -19.1 265 36 19 8.6 4.7 36.4 97.6 5.0 M M 25000 -26.4 -15.5 265 32 17 7.3 4.0 35.2 95.4 4.1 M M 24000 -24.0 -11.2 255 29 15 7.0 3.9 34.6 94.2 3.6 M M 23000 -21.9 -7.4 265 25 13 8.4 4.6 33.6 92.5 2.9 M M 22000 -19.6 -3.3 265 25 13 7.3 4.0 32.8 91.1 2.3 M M 21000 -17.4 0.7 255 31 16 7.3 4.0 31.9 89.5 1.6 M M 20000 -15.2 4.6 255 34 17 7.3 4.0 31.1 87.9 0.8 M M 19500 -14.1 6.6 255 35 18 7.2 3.9 30.6 87.1 0.5 M M 19000 -13.0 8.6 255 37 19 6.1 3.3 30.1 86.3 0.1 M M 18500 -12.2 10.0 255 37 19 6.3 3.5 29.4 85.0 -0.6 1248 6.3 18000 -11.3 11.7 260 36 18 6.1 3.4 28.8 83.8 -1.1 1206 6.1 17500 -9.9 14.2 270 32 17 6.2 3.4 27.9 82.1 -2.0 1143 5.8 17000 -9.0 15.8 280 31 16 5.9 3.2 27.3 81.1 -2.5 1102 5.6 16500 -8.0 17.6 285 33 17 9.3 5.1 26.9 80.4 -2.9 1054 5.4 16000 -6.6 20.1 285 30 15 9.4 5.1 26.8 80.3 -3.0 997 5.1 15500 -5.2 22.6 285 30 15 9.4 5.2 26.7 80.1 -3.1 941 4.8 15000 -3.8 25.2 285 29 15 9.2 5.0 26.6 79.9 -3.2 885 4.5 14500 -2.6 27.3 285 28 15 7.5 4.1 26.4 79.5 -3.5 834 4.2 14000 -1.4 29.5 280 23 12 7.6 4.2 26.1 78.9 -3.8 785 4.0 13500 -0.3 31.5 285 19 10 7.6 4.2 25.7 78.3 -4.2 736 3.7 13000 0.8 33.4 290 17 9 7.5 4.1 25.4 77.7 -4.5 687 3.5 12500 2.0 35.6 290 14 7 8.8 4.8 25.1 77.2 -4.8 637 3.2 12000 3.3 37.9 305 15 8 8.8 4.8 25.0 76.9 -5.0 583 3.0 11500 4.7 40.5 310 17 9 9.6 5.3 24.9 76.9 -5.1 526 2.7 11000 6.0 42.8 305 18 9 8.7 4.8 24.8 76.6 -5.3 472 2.4 10500 7.3 45.1 310 15 8 8.2 4.5 24.6 76.3 -5.5 419 2.1 10250 7.8 46.0 315 16 8 6.9 3.8 24.4 76.0 -5.7 396 2.0 10000 8.3 46.9 320 15 8 6.9 3.8 24.2 75.6 -5.9 373 1.9 9750 8.9 48.0 320 12 6 6.9 3.8 24.0 75.2 -6.1 350 1.8 9500 9.4 48.9 320 13 7 6.9 3.8 23.8 74.8 -6.4 328 1.7 9250 9.9 49.8 330 11 6 6.9 3.8 23.6 74.4 -6.6 305 1.5 9000 10.4 50.7 340 9 5 6.9 3.8 23.3 74.0 -6.8 282 1.4 8750 10.9 51.6 340 8 4 6.9 3.8 23.1 73.6 -7.1 259 1.3 8500 11.4 52.5 330 6 3 6.9 3.8 22.9 73.2 -7.3 236 1.2 8250 11.9 53.4 305 4 2 6.9 3.8 22.7 72.8 -7.6 214 1.1 8000 12.5 54.5 260 3 1 6.8 3.7 22.4 72.4 -7.8 191 1.0 7750 13.0 55.4 240 1 1 7.2 4.0 22.2 72.0 -8.0 168 0.9 7500 13.5 56.3 050 1 1 7.7 4.2 22.0 71.7 -8.2 144 0.7 7250 14.1 57.4 050 4 2 7.6 4.2 21.9 71.4 -8.4 119 0.6 7000 14.7 58.5 055 5 3 7.6 4.2 21.7 71.1 -8.6 95 0.5 6750 15.2 59.4 055 6 3 7.6 4.2 21.6 70.8 -8.8 71 0.4 6500 15.8 60.4 050 5 3 7.6 4.2 21.4 70.5 -9.0 46 0.2 6250 16.4 61.5 045 5 2 7.6 4.2 21.2 70.2 -9.2 22 0.1 6000 16.9 62.4 040 4 2 7.7 4.2 21.1 69.9 -9.3 M M 5750 17.5 63.5 040 4 2 7.4 4.0 20.9 69.6 -9.5 M M 5500 18.0 64.4 040 4 2 8.4 4.6 20.7 69.3 -9.7 M M 5250 18.6 65.5 055 6 3 4.5 2.4 20.5 69.0 -10.0 M M 5000 18.2 64.8 065 8 4 -19.9 -10.9 19.4 66.9 -11.1 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 05/31/2024 at 0900 MDT | 05/31/2024 at 1200 MDT | CAPE... 0.0 LI... +1.8 | CAPE... 0.0 LI... +0.9 CINH... -0.8 K Index... +13.2 | CINH... -0.1 K Index... +20.3 | 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 -56.9 -70.4 270 30 15 -0.4 -0.2 | -56.9 -70.4 265 31 16 -0.2 -0.1 45000 -57.6 -71.7 265 37 19 -1.0 -0.5 | -57.3 -71.1 265 41 21 -0.9 -0.5 40000 -59.0 -74.2 270 37 19 -1.5 -0.8 | -58.6 -73.5 265 44 23 -1.4 -0.8 38000 -56.1 -69.0 265 38 20 6.1 3.4 | -55.5 -67.9 265 43 22 6.4 3.5 36000 -52.4 -62.3 265 41 21 6.1 3.4 | -51.1 -60.0 265 42 21 6.4 3.5 34000 -47.8 -54.0 265 41 21 7.6 4.2 | -47.3 -53.1 265 42 21 6.4 3.5 32000 -43.2 -45.8 265 41 21 7.6 4.2 | -43.5 -46.3 265 43 22 6.4 3.5 30000 -38.5 -37.3 265 41 21 8.2 4.5 | -39.1 -38.4 270 42 22 8.1 4.4 29000 -36.1 -33.0 265 41 21 8.2 4.5 | -36.7 -34.1 270 41 21 8.1 4.5 28000 -33.6 -28.5 270 41 21 8.2 4.5 | -34.3 -29.7 270 40 20 8.1 4.5 27000 -31.3 -24.3 270 40 21 7.9 4.3 | -31.9 -25.4 270 38 19 7.7 4.2 26000 -28.9 -20.0 270 39 20 7.9 4.3 | -29.7 -21.5 270 36 18 7.7 4.2 25000 -26.5 -15.7 275 37 19 7.9 4.3 | -27.4 -17.3 270 33 17 7.7 4.2 24000 -24.4 -11.9 275 36 18 6.0 3.3 | -25.1 -13.2 265 32 16 7.4 4.1 23000 -22.6 -8.7 275 35 18 6.1 3.3 | -22.9 -9.2 265 31 16 7.5 4.1 22000 -20.8 -5.4 275 34 18 6.1 3.4 | -20.2 -4.4 265 30 16 7.5 4.1 21000 -18.3 -0.9 275 32 17 6.9 3.8 | -18.1 -0.6 270 29 15 7.1 3.9 20000 -16.3 2.7 275 31 16 7.0 3.8 | -16.0 3.2 270 28 14 7.1 3.9 19500 -15.3 4.5 275 30 15 7.0 3.8 | -14.9 5.2 270 27 14 7.1 3.9 19000 -14.2 6.4 275 29 15 7.6 4.2 | -13.9 7.0 270 26 13 7.6 4.2 18500 -13.1 8.4 280 28 15 7.9 4.3 | -12.7 9.1 270 25 13 7.8 4.3 18000 -11.9 10.6 280 28 14 8.0 4.4 | -11.6 11.1 270 25 13 7.8 4.3 17500 -10.7 12.7 285 27 14 8.7 4.8 | -10.4 13.3 270 24 12 8.2 4.5 17000 -9.4 15.1 285 27 14 8.6 4.7 | -9.2 15.4 270 23 12 8.2 4.5 16500 -8.1 17.4 285 26 13 8.9 4.9 | -8.0 17.6 270 22 12 8.2 4.5 16000 -6.8 19.8 285 25 13 9.0 4.9 | -6.8 19.8 270 21 11 8.2 4.5 15500 -5.5 22.1 285 24 12 8.8 4.9 | -5.6 21.9 265 21 11 8.3 4.6 15000 -4.2 24.4 285 23 12 8.7 4.8 | -4.4 24.1 265 20 10 8.5 4.7 14500 -2.9 26.8 280 22 11 8.6 4.7 | -3.1 26.4 265 19 10 8.5 4.7 14000 -1.6 29.1 280 20 10 8.5 4.7 | -1.8 28.8 265 18 9 8.5 4.7 13500 -0.3 31.5 280 18 9 8.6 4.7 | -0.5 31.1 265 17 9 8.5 4.6 13000 0.9 33.6 280 16 8 8.2 4.5 | 0.7 33.3 260 17 9 8.8 4.8 12500 2.2 36.0 280 14 7 8.2 4.5 | 2.1 35.8 260 16 8 8.8 4.8 12000 3.4 38.1 280 12 6 8.1 4.5 | 3.4 38.1 260 15 8 8.7 4.8 11500 4.6 40.3 285 11 5 8.2 4.5 | 4.7 40.5 260 14 7 8.8 4.8 11000 5.8 42.4 285 9 5 7.6 4.2 | 5.9 42.6 260 13 7 8.1 4.4 10500 6.9 44.4 285 7 4 8.0 4.4 | 7.2 45.0 260 12 6 7.5 4.1 10250 7.5 45.5 285 6 3 6.0 3.3 | 7.8 46.0 260 12 6 10.5 5.8 10000 7.9 46.2 285 6 3 6.3 3.5 | 8.7 47.7 260 11 6 10.9 6.0 9750 8.5 47.3 280 5 2 8.4 4.6 | 9.3 48.7 260 10 5 8.1 4.4 9500 9.1 48.4 275 4 2 7.9 4.3 | 10.0 50.0 265 10 5 9.1 5.0 9250 9.7 49.5 265 3 2 8.0 4.4 | 10.6 51.1 265 9 5 7.9 4.3 9000 10.2 50.4 245 3 1 7.2 3.9 | 11.2 52.2 265 8 4 8.0 4.4 8750 10.7 51.3 225 3 1 6.7 3.6 | 11.8 53.2 270 8 4 8.9 4.9 8500 11.2 52.2 200 3 1 6.9 3.8 | 13.1 55.6 275 7 4 6.8 3.7 8250 11.7 53.1 185 3 2 5.6 3.1 | 13.6 56.5 280 7 4 7.2 4.0 8000 12.5 54.5 180 4 2 7.0 3.8 | 14.3 57.7 280 7 3 10.7 5.9 7750 13.0 55.4 170 4 2 6.4 3.5 | 15.1 59.2 285 6 3 10.1 5.5 7500 13.4 56.1 165 4 2 3.8 2.1 | 15.7 60.3 285 6 3 7.4 4.1 7250 13.6 56.5 160 4 2 3.1 1.7 | 16.2 61.2 290 6 3 7.0 3.8 7000 14.0 57.2 160 4 2 8.6 4.7 | 16.9 62.4 290 6 3 11.7 6.4 6750 14.7 58.5 150 4 2 9.5 5.2 | 17.9 64.2 290 6 3 12.1 6.6 6500 15.3 59.5 145 4 2 6.6 3.6 | 18.6 65.5 295 6 3 9.6 5.3 6250 15.8 60.4 140 4 2 6.4 3.5 | 19.3 66.7 295 6 3 9.4 5.1 6000 16.3 61.3 135 4 2 10.0 5.5 | 20.1 68.2 300 6 3 11.0 6.0 5750 17.4 63.3 135 3 2 20.3 11.1 | 21.2 70.2 295 5 3 20.7 11.3 5500 18.8 65.8 130 3 2 12.8 7.0 | 23.3 73.9 300 5 2 37.2 20.4 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 05/31/2024 at 1500 MDT | 05/31/2024 at 1800 MDT | CAPE... +75.7 LI... -0.3 | CAPE... +99.2 LI... -0.4 CINH... -29.9 K Index... +22.8 | CINH... -29.6 K Index... +22.0 | 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 -57.3 -71.1 260 33 17 -0.4 -0.2 | -57.1 -70.8 265 35 18 -0.1 -0.1 45000 -57.9 -72.2 265 41 21 -0.4 -0.2 | -57.4 -71.3 270 43 22 -0.6 -0.3 40000 -58.4 -73.1 260 48 25 -0.8 -0.5 | -58.3 -72.9 265 50 26 -1.0 -0.6 38000 -55.5 -67.9 265 47 24 5.9 3.3 | -55.9 -68.6 265 49 25 5.0 2.7 36000 -51.5 -60.7 265 45 23 5.9 3.3 | -52.5 -62.5 270 46 23 5.0 2.7 34000 -47.7 -53.9 265 44 23 6.6 3.6 | -48.5 -55.3 270 44 23 7.9 4.3 32000 -43.7 -46.7 265 44 23 6.6 3.6 | -43.8 -46.8 265 42 22 7.9 4.3 30000 -39.2 -38.6 270 43 22 8.3 4.6 | -39.0 -38.2 270 41 21 8.3 4.5 29000 -36.8 -34.2 270 42 22 8.3 4.6 | -36.5 -33.7 270 39 20 8.3 4.6 28000 -34.3 -29.7 270 42 21 8.3 4.6 | -34.0 -29.2 270 38 20 8.3 4.6 27000 -31.9 -25.4 270 40 20 7.7 4.2 | -31.6 -24.9 270 37 19 7.9 4.3 26000 -29.6 -21.3 270 36 19 7.7 4.2 | -29.3 -20.7 270 36 18 7.9 4.3 25000 -27.3 -17.1 270 33 17 7.8 4.3 | -27.0 -16.6 270 34 18 7.9 4.3 24000 -25.1 -13.2 270 31 16 7.4 4.1 | -24.7 -12.5 265 33 17 7.6 4.2 23000 -22.3 -8.1 265 30 15 7.5 4.1 | -21.8 -7.2 260 30 16 7.7 4.2 22000 -20.1 -4.2 260 29 15 7.4 4.1 | -19.6 -3.3 255 29 15 7.7 4.2 21000 -17.8 -0.0 260 29 15 7.7 4.2 | -17.3 0.9 255 28 14 7.9 4.3 20000 -15.6 3.9 255 28 15 7.7 4.2 | -15.0 5.0 250 27 14 7.9 4.3 19500 -14.4 6.1 255 28 14 7.7 4.2 | -13.8 7.2 245 26 13 7.9 4.3 19000 -13.3 8.1 250 28 14 8.2 4.5 | -12.7 9.1 245 26 13 8.0 4.4 18500 -12.0 10.4 250 27 14 8.3 4.5 | -11.5 11.3 240 25 13 8.1 4.4 18000 -10.8 12.6 250 26 13 8.3 4.6 | -10.3 13.5 240 24 12 8.2 4.5 17500 -9.6 14.7 250 25 13 8.5 4.7 | -9.0 15.8 240 23 12 8.6 4.7 17000 -8.4 16.9 250 24 12 8.5 4.7 | -7.8 18.0 240 22 11 8.6 4.7 16500 -7.1 19.2 250 23 12 8.8 4.8 | -6.5 20.3 240 21 11 9.0 4.9 16000 -5.8 21.6 250 22 11 8.8 4.8 | -5.1 22.8 240 20 10 9.0 5.0 15500 -4.5 23.9 250 20 10 8.8 4.8 | -3.8 25.2 245 20 10 9.1 5.0 15000 -3.2 26.2 250 19 10 8.8 4.8 | -2.4 27.7 245 19 10 9.2 5.1 14500 -1.9 28.6 250 18 9 8.9 4.9 | -1.1 30.0 245 18 9 9.2 5.1 14000 -0.5 31.1 255 17 9 9.3 5.1 | 0.3 32.5 250 17 9 9.3 5.1 13500 0.9 33.6 255 16 8 9.2 5.1 | 1.7 35.1 255 17 9 9.3 5.1 13000 2.2 36.0 255 15 8 9.0 5.0 | 3.0 37.4 255 16 8 9.0 5.0 12500 3.6 38.5 260 15 8 9.1 5.0 | 4.4 39.9 260 15 8 9.0 5.0 12000 4.9 40.8 265 14 7 9.2 5.0 | 5.8 42.4 265 14 7 9.2 5.1 11500 6.3 43.3 265 13 7 9.3 5.1 | 7.1 44.8 270 14 7 9.4 5.1 11000 7.5 45.5 270 13 7 7.4 4.1 | 8.4 47.1 275 13 7 7.5 4.1 10500 8.6 47.5 275 13 7 7.0 3.9 | 9.5 49.1 280 12 6 7.6 4.2 10250 9.3 48.7 275 13 7 11.8 6.5 | 10.2 50.4 280 11 6 11.3 6.2 10000 10.3 50.5 280 12 6 11.9 6.5 | 11.1 52.0 285 11 6 11.0 6.0 9750 10.9 51.6 280 12 6 7.8 4.3 | 11.7 53.1 290 10 5 8.2 4.5 9500 11.6 52.9 285 12 6 9.4 5.2 | 12.4 54.3 295 9 5 9.2 5.0 9250 12.2 54.0 285 12 6 7.2 4.0 | 13.0 55.4 295 9 5 8.1 4.4 9000 12.7 54.9 290 11 6 8.1 4.4 | 13.6 56.5 300 9 4 8.9 4.9 8750 13.5 56.3 295 11 6 10.4 5.7 | 15.1 59.2 310 8 4 10.1 5.5 8500 14.9 58.8 300 10 5 9.1 5.0 | 15.8 60.4 315 8 4 9.5 5.2 8250 15.6 60.1 300 10 5 9.2 5.1 | 16.5 61.7 310 8 4 9.5 5.2 8000 16.3 61.3 305 10 5 10.8 5.9 | 17.3 63.1 315 8 4 10.3 5.6 7750 17.1 62.8 305 9 5 10.4 5.7 | 18.0 64.4 320 8 4 10.2 5.6 7500 17.9 64.2 305 9 5 8.8 4.8 | 18.8 65.8 320 8 4 9.0 4.9 7250 18.5 65.3 310 10 5 8.5 4.7 | 19.4 66.9 320 8 4 8.6 4.7 7000 19.2 66.6 310 9 5 11.1 6.1 | 20.1 68.2 320 8 4 10.2 5.6 6750 20.1 68.2 310 9 5 11.6 6.4 | 20.9 69.6 325 8 4 10.9 6.0 6500 20.9 69.6 310 9 5 10.6 5.8 | 21.7 71.1 325 8 4 10.7 5.9 6250 21.7 71.1 315 9 5 10.5 5.8 | 22.5 72.5 325 8 4 11.4 6.2 6000 22.4 72.3 315 9 5 10.1 5.5 | 23.3 73.9 325 8 4 7.7 4.2 5750 23.4 74.1 315 8 4 18.6 10.2 | 23.8 74.8 330 7 4 8.4 4.6 5500 26.1 79.0 320 8 4 63.4 34.8 | 25.9 78.6 330 7 4 63.0 34.6 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 ________________________________________________________________________________ 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