Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
381 UXUS97 KGJT 211307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Tuesday, May 21, 2024 This forecast is for Tuesday, May 21, 2024: If the trigger temperature of 55.1 F/12.9 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 812 ft/min (4.1 m/s) Maximum height of thermals.................. 14961 ft MSL (10122 ft AGL) Forecast maximum temperature................... 67.0 F/19.9 C Time of trigger temperature.................... 0945 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................. 12425 ft MSL (7586 ft AGL) Thermal soaring outlook for Wednesday 05/22.... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:55:34 / 20:26:02 MDT Total possible sunshine........... 14 hr 30 min 28 sec (870 min 28 sec) Altitude of sun at 13:10:48 MDT... 71.14 degrees Upper air data from rawinsonde observation taken on 05/21/2024 at 0600 MDT Freezing level.................. 9332 ft MSL (4493 ft AGL) Convective condensation level... 9627 ft MSL (4788 ft AGL) Lifted condensation level....... 12072 ft MSL (7232 ft AGL) Lifted index.................... -2.7 K index......................... +20.7 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 -49.9 -57.8 235 54 28 3.2 1.7 116.7 242.0 55.7 M M 45000 -48.5 -55.3 240 58 30 5.7 3.1 94.5 202.1 45.9 M M 40000 -46.1 -51.0 250 58 30 -2.9 -1.6 74.0 165.1 35.7 M M 38000 -47.0 -52.6 255 54 28 -5.8 -3.2 63.7 146.7 29.7 M M 36000 -50.6 -59.1 245 65 33 -5.9 -3.2 49.9 121.9 21.0 M M 34000 -52.0 -61.6 250 62 32 1.9 1.0 39.5 103.1 14.2 M M 32000 -50.1 -58.2 255 58 30 4.3 2.4 34.0 93.2 10.6 M M 30000 -45.1 -49.2 250 50 26 8.3 4.6 31.8 89.3 9.3 M M 29000 -42.8 -45.0 245 47 24 7.5 4.1 31.0 87.8 8.8 M M 28000 -40.6 -41.1 245 50 26 7.8 4.3 30.1 86.3 8.2 M M 27000 -38.1 -36.6 240 44 23 10.4 5.7 29.6 85.2 7.8 M M 26000 -35.5 -31.9 235 46 24 8.1 4.5 29.2 84.6 7.6 M M 25000 -33.1 -27.6 235 46 24 8.7 4.8 28.6 83.5 7.2 M M 24000 -30.8 -23.4 235 40 21 7.2 4.0 27.9 82.3 6.8 M M 23000 -28.3 -18.9 235 42 22 8.1 4.5 27.4 81.4 6.4 M M 22000 -26.0 -14.8 240 38 19 7.2 3.9 26.7 80.0 5.8 M M 21000 -23.8 -10.8 240 39 20 7.9 4.4 25.8 78.4 5.2 M M 20000 -21.5 -6.7 245 34 17 7.8 4.3 25.1 77.2 4.6 M M 19500 -20.4 -4.7 245 33 17 7.7 4.2 24.8 76.6 4.3 M M 19000 -19.2 -2.6 250 35 18 7.6 4.2 24.4 75.9 4.0 M M 18500 -18.1 -0.6 250 34 17 6.8 3.7 24.0 75.3 3.7 M M 18000 -17.3 0.9 260 39 20 4.2 2.3 23.2 73.8 3.0 M M 17500 -16.8 1.8 260 41 21 4.9 2.7 22.2 72.0 2.2 M M 17000 -15.8 3.6 265 38 19 7.5 4.1 21.7 71.0 1.7 M M 16500 -14.6 5.7 265 42 22 7.9 4.3 21.3 70.4 1.4 M M 16000 -12.9 8.8 265 38 20 6.9 3.8 20.8 69.5 0.9 M M 15500 -12.0 10.4 270 37 19 6.6 3.6 20.3 68.5 0.4 M M 15000 -11.0 12.2 265 31 16 6.6 3.6 19.8 67.6 -0.1 807 4.1 14500 -10.0 14.0 270 32 16 6.7 3.7 19.2 66.6 -0.6 763 3.9 14000 -9.2 15.4 275 25 13 5.2 2.9 18.6 65.5 -1.2 722 3.7 13500 -8.4 16.9 280 25 13 5.3 2.9 17.9 64.2 -1.9 685 3.5 13000 -7.6 18.3 275 24 12 6.3 3.4 17.1 62.9 -2.6 647 3.3 12500 -6.6 20.1 290 18 9 7.0 3.8 16.7 62.1 -3.0 601 3.1 12000 -5.5 22.1 290 22 11 6.9 3.8 16.3 61.3 -3.4 554 2.8 11500 -4.5 23.9 285 19 10 5.2 2.9 15.8 60.5 -3.8 508 2.6 11000 -4.0 24.8 280 15 8 6.6 3.6 14.9 58.8 -4.8 479 2.4 10500 -2.9 26.8 285 13 7 6.3 3.5 14.5 58.1 -5.2 432 2.2 10250 -2.5 27.5 285 14 7 7.2 3.9 14.3 57.7 -5.5 411 2.1 10000 -1.9 28.6 285 15 8 9.0 4.9 14.1 57.4 -5.7 386 2.0 9750 -1.2 29.8 290 13 7 9.4 5.2 14.1 57.4 -5.7 357 1.8 9500 -0.5 31.1 290 12 6 9.7 5.3 14.1 57.3 -5.8 329 1.7 9250 0.2 32.4 300 10 5 8.3 4.5 14.0 57.3 -5.8 301 1.5 9000 0.7 33.3 305 9 5 6.1 3.4 13.8 56.9 -6.1 279 1.4 8750 1.1 34.0 305 7 4 5.8 3.2 13.5 56.4 -6.4 259 1.3 8500 1.5 34.7 300 6 3 6.5 3.6 13.2 55.8 -6.7 240 1.2 8250 2.0 35.6 275 5 3 7.3 4.0 13.0 55.5 -7.0 217 1.1 8000 2.6 36.7 245 8 4 7.3 4.0 12.9 55.1 -7.2 194 1.0 7750 3.1 37.6 240 8 4 7.3 4.0 12.7 54.8 -7.4 170 0.9 7500 3.6 38.5 245 10 5 7.3 4.0 12.5 54.5 -7.6 147 0.7 7250 4.2 39.6 235 7 4 7.4 4.1 12.3 54.1 -7.8 123 0.6 7000 4.7 40.5 225 5 3 7.1 3.9 12.1 53.8 -8.0 100 0.5 6750 5.2 41.4 225 5 3 8.2 4.5 11.9 53.5 -8.2 77 0.4 6500 5.9 42.6 210 6 3 10.0 5.5 11.9 53.4 -8.3 49 0.2 6250 6.6 43.9 195 4 2 10.2 5.6 11.9 53.5 -8.3 20 0.1 6000 7.4 45.3 155 2 1 10.3 5.6 12.0 53.6 -8.3 M M 5750 8.1 46.6 145 2 1 9.1 5.0 12.0 53.6 -8.4 M M 5500 8.7 47.7 135 1 1 8.2 4.5 11.9 53.4 -8.5 M M 5250 9.2 48.6 110 1 0 7.7 4.2 11.8 53.2 -8.7 M M 5000 9.6 49.3 060 1 0 5.6 3.1 11.5 52.8 -9.1 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 05/21/2024 at 0900 MDT | 05/21/2024 at 1200 MDT | CAPE... +185.5 LI... 0.0 | CAPE... +111.2 LI... +1.1 CINH... -0.4 K Index... +22.0 | CINH... -0.8 K Index... +18.5 | 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 -51.5 -60.7 235 47 24 2.5 1.4 | -51.0 -59.8 240 48 25 2.1 1.2 45000 -47.9 -54.2 250 52 27 0.6 0.3 | -47.9 -54.2 250 51 26 0.3 0.2 40000 -47.1 -52.8 250 60 31 0.5 0.3 | -47.5 -53.5 250 61 31 0.2 0.1 38000 -47.6 -53.7 250 65 33 -2.1 -1.1 | -47.7 -53.9 250 65 34 -0.7 -0.4 36000 -48.8 -55.8 250 71 37 -2.1 -1.2 | -48.1 -54.6 250 68 35 -0.7 -0.4 34000 -49.7 -57.5 245 76 39 3.5 1.9 | -48.3 -54.9 250 71 37 2.1 1.1 32000 -47.8 -54.0 245 74 38 3.3 1.8 | -47.0 -52.6 250 70 36 2.1 1.2 30000 -45.5 -49.9 240 71 36 7.3 4.0 | -45.6 -50.1 245 69 35 5.7 3.1 29000 -43.4 -46.1 240 67 34 7.0 3.8 | -43.8 -46.8 245 66 34 5.8 3.2 28000 -41.3 -42.3 240 63 32 7.0 3.8 | -42.1 -43.8 245 64 33 5.8 3.2 27000 -39.3 -38.7 240 59 30 6.9 3.8 | -40.4 -40.7 240 61 31 5.5 3.0 26000 -37.0 -34.6 240 56 29 7.8 4.3 | -38.2 -36.8 240 59 30 8.0 4.4 25000 -34.7 -30.5 245 53 27 7.8 4.3 | -35.8 -32.4 240 57 29 8.0 4.4 24000 -31.8 -25.2 245 49 25 7.7 4.2 | -33.4 -28.1 240 55 28 8.0 4.4 23000 -29.5 -21.1 250 48 25 7.6 4.2 | -30.4 -22.7 240 53 27 8.2 4.5 22000 -27.2 -17.0 250 47 24 7.6 4.2 | -27.9 -18.2 240 52 27 8.2 4.5 21000 -25.0 -13.0 250 46 24 7.5 4.1 | -25.5 -13.9 245 51 26 7.8 4.3 20000 -22.8 -9.0 255 44 23 7.5 4.1 | -23.3 -9.9 245 50 26 7.6 4.2 19500 -21.7 -7.1 255 43 22 7.5 4.1 | -22.1 -7.8 245 49 25 7.6 4.2 19000 -20.6 -5.1 255 42 22 7.5 4.1 | -21.0 -5.8 250 49 25 7.6 4.1 18500 -19.4 -2.9 255 41 21 7.4 4.1 | -19.9 -3.8 250 48 25 7.1 3.9 18000 -18.4 -1.1 255 40 20 7.4 4.0 | -18.9 -2.0 250 47 24 6.7 3.7 17500 -17.3 0.9 255 39 20 7.4 4.0 | -17.9 -0.2 250 45 23 6.7 3.7 17000 -16.2 2.8 255 37 19 7.0 3.8 | -16.9 1.6 250 44 22 6.5 3.6 16500 -15.2 4.6 255 36 18 7.1 3.9 | -15.9 3.4 250 42 21 6.6 3.6 16000 -14.2 6.4 255 34 18 6.6 3.6 | -15.0 5.0 250 40 20 6.9 3.8 15500 -13.2 8.2 255 32 17 6.5 3.6 | -13.9 7.0 255 38 20 6.9 3.8 15000 -12.3 9.9 255 31 16 6.1 3.3 | -12.9 8.8 255 36 19 6.7 3.7 14500 -11.4 11.5 255 29 15 5.7 3.1 | -12.0 10.4 255 34 18 6.5 3.6 14000 -10.6 12.9 255 27 14 5.7 3.1 | -11.0 12.2 255 32 17 6.2 3.4 13500 -9.7 14.5 255 26 13 5.9 3.2 | -10.2 13.6 255 30 15 5.3 2.9 13000 -8.9 16.0 255 24 12 6.0 3.3 | -9.4 15.1 260 27 14 5.5 3.0 12500 -7.9 17.8 255 22 11 6.6 3.6 | -8.6 16.5 260 25 13 6.0 3.3 12000 -7.0 19.4 260 20 10 6.5 3.6 | -7.7 18.1 260 23 12 6.1 3.4 11500 -6.1 21.0 260 18 9 6.4 3.5 | -6.7 19.9 260 21 11 7.2 4.0 11000 -5.1 22.8 265 17 9 6.4 3.5 | -5.6 21.9 255 20 10 7.2 3.9 10500 -4.2 24.4 265 16 8 6.2 3.4 | -4.6 23.7 260 19 10 7.0 3.9 10250 -3.8 25.2 265 15 8 5.9 3.2 | -4.1 24.6 260 18 9 7.3 4.0 10000 -3.3 26.1 265 15 8 8.2 4.5 | -3.5 25.7 260 18 9 10.6 5.8 9750 -2.7 27.1 270 13 7 8.4 4.6 | -2.6 27.3 260 17 9 10.5 5.7 9500 -2.2 28.0 270 13 7 6.5 3.6 | -2.0 28.4 265 16 8 8.0 4.4 9250 -1.7 28.9 270 12 6 7.1 3.9 | -1.3 29.7 265 16 8 9.0 5.0 9000 -1.2 29.8 270 12 6 6.5 3.6 | -0.7 30.7 265 15 8 7.5 4.1 8750 -0.7 30.7 270 12 6 6.9 3.8 | -0.2 31.6 270 15 8 8.3 4.6 8500 -0.1 31.8 275 11 6 7.8 4.3 | 1.2 34.2 270 14 7 9.6 5.3 8250 0.4 32.7 275 11 5 7.5 4.1 | 1.9 35.4 270 13 7 9.1 5.0 8000 1.4 34.5 275 10 5 7.7 4.2 | 2.6 36.7 275 13 7 9.9 5.4 7750 2.0 35.6 275 9 5 9.9 5.4 | 3.4 38.1 270 13 7 11.2 6.1 7500 2.7 36.9 275 9 4 8.1 4.4 | 4.2 39.6 270 13 6 9.6 5.3 7250 3.2 37.8 275 8 4 5.3 2.9 | 4.8 40.6 275 13 7 7.3 4.0 7000 3.6 38.5 275 8 4 9.0 4.9 | 5.4 41.7 275 13 7 10.0 5.5 6750 4.5 40.1 275 7 4 12.3 6.8 | 6.3 43.3 275 12 6 12.4 6.8 6500 5.3 41.5 275 7 3 9.6 5.3 | 7.1 44.8 275 12 6 10.5 5.8 6250 5.9 42.6 275 6 3 8.7 4.8 | 7.9 46.2 275 12 6 10.6 5.8 6000 6.6 43.9 275 6 3 8.9 4.9 | 8.7 47.7 275 12 6 8.6 4.7 5750 7.3 45.1 275 6 3 12.2 6.7 | 9.3 48.7 275 10 5 12.3 6.8 5500 8.7 47.7 275 5 2 32.6 17.9 | 11.7 53.1 280 10 5 67.4 37.0 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 05/21/2024 at 1500 MDT | 05/21/2024 at 1800 MDT | CAPE... +65.2 LI... 0.0 | CAPE... +29.1 LI... 0.0 CINH... -1.4 K Index... +16.0 | CINH... -27.6 K Index... +15.5 | 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 -51.1 -60.0 245 45 23 1.1 0.6 | -51.5 -60.7 245 45 23 0.9 0.5 45000 -49.4 -56.9 250 53 27 0.2 0.1 | -50.2 -58.4 255 54 28 -1.3 -0.7 40000 -49.2 -56.6 260 69 35 0.1 0.1 | -52.1 -61.8 260 71 37 -1.3 -0.7 38000 -49.0 -56.2 260 73 38 0.3 0.2 | -51.5 -60.7 260 76 39 3.0 1.6 36000 -48.8 -55.8 255 74 38 0.3 0.2 | -49.7 -57.5 265 78 40 3.0 1.6 34000 -48.3 -54.9 255 75 39 4.9 2.7 | -47.8 -54.0 265 80 41 3.6 2.0 32000 -45.7 -50.3 255 78 40 4.4 2.4 | -45.7 -50.3 265 79 41 3.6 2.0 30000 -42.9 -45.2 260 81 42 6.5 3.6 | -43.2 -45.8 270 77 40 7.0 3.8 29000 -41.0 -41.8 260 81 42 6.2 3.4 | -41.2 -42.2 270 76 39 6.7 3.7 28000 -39.2 -38.6 260 80 41 6.2 3.4 | -39.2 -38.6 270 75 38 6.7 3.7 27000 -37.3 -35.1 255 80 41 6.5 3.5 | -37.2 -35.0 270 73 38 6.7 3.7 26000 -35.8 -32.4 255 76 39 4.5 2.5 | -35.2 -31.4 270 68 35 6.4 3.5 25000 -34.5 -30.1 255 70 36 4.5 2.5 | -33.3 -27.9 275 63 33 6.4 3.5 24000 -33.1 -27.6 255 64 33 4.4 2.4 | -31.4 -24.5 280 59 30 6.5 3.6 23000 -31.0 -23.8 255 58 30 6.0 3.3 | -29.3 -20.7 285 52 27 5.4 3.0 22000 -29.3 -20.7 255 53 27 6.0 3.3 | -27.7 -17.9 285 47 24 5.4 3.0 21000 -27.4 -17.3 255 48 25 7.0 3.8 | -26.0 -14.8 290 42 22 5.0 2.7 20000 -25.3 -13.5 255 44 23 7.3 4.0 | -24.6 -12.3 290 37 19 5.0 2.7 19500 -24.2 -11.6 255 42 22 7.4 4.0 | -23.9 -11.0 285 35 18 5.0 2.8 19000 -23.1 -9.6 260 40 20 7.4 4.1 | -23.1 -9.6 285 32 16 5.0 2.8 18500 -22.0 -7.6 260 38 19 7.6 4.2 | -22.3 -8.1 285 30 15 6.7 3.7 18000 -20.8 -5.4 260 36 18 7.8 4.3 | -21.3 -6.3 280 28 15 7.3 4.0 17500 -19.7 -3.5 260 33 17 7.8 4.3 | -20.2 -4.4 280 27 14 7.6 4.2 17000 -18.6 -1.5 260 31 16 7.2 4.0 | -19.0 -2.2 280 26 13 8.7 4.8 16500 -17.5 0.5 265 29 15 7.2 4.0 | -17.7 0.1 280 25 13 8.7 4.8 16000 -16.4 2.5 265 27 14 7.7 4.2 | -16.4 2.5 280 25 13 8.5 4.7 15500 -15.3 4.5 265 25 13 7.7 4.2 | -15.2 4.6 280 24 13 8.5 4.7 15000 -14.1 6.6 265 23 12 8.0 4.4 | -13.9 7.0 280 24 12 8.5 4.7 14500 -13.0 8.6 265 22 11 8.1 4.5 | -12.7 9.1 285 23 12 8.5 4.7 14000 -11.8 10.8 260 21 11 8.2 4.5 | -11.4 11.5 285 22 11 8.8 4.8 13500 -10.5 13.1 260 20 10 8.4 4.6 | -10.1 13.8 285 21 11 9.0 4.9 13000 -9.3 15.3 260 19 10 8.5 4.7 | -8.7 16.3 290 21 11 9.1 5.0 12500 -8.0 17.6 265 19 10 8.9 4.9 | -7.3 18.9 290 20 10 9.1 5.0 12000 -6.7 19.9 265 18 9 8.9 4.9 | -6.0 21.2 290 20 10 9.2 5.0 11500 -5.4 22.3 265 18 9 9.0 4.9 | -4.6 23.7 290 19 10 9.3 5.1 11000 -4.0 24.8 260 17 9 8.6 4.7 | -3.2 26.2 295 19 10 8.6 4.7 10500 -2.8 27.0 265 16 8 7.1 3.9 | -2.0 28.4 295 19 10 6.9 3.8 10250 -2.3 27.9 265 16 8 9.5 5.2 | -1.5 29.3 295 19 10 10.9 6.0 10000 -1.4 29.5 265 16 8 12.0 6.6 | -0.5 31.1 295 18 9 12.3 6.7 9750 -0.6 30.9 265 16 8 10.0 5.5 | 0.2 32.4 295 18 9 8.9 4.9 9500 0.1 32.2 265 15 8 9.1 5.0 | 0.9 33.6 295 18 9 9.6 5.3 9250 0.8 33.4 265 15 8 9.0 4.9 | 1.6 34.9 300 17 9 8.7 4.8 9000 1.4 34.5 265 15 7 8.3 4.6 | 2.2 36.0 300 17 9 8.0 4.4 8750 2.1 35.8 265 14 7 9.8 5.4 | 2.9 37.2 300 17 9 9.3 5.1 8500 2.9 37.2 265 14 7 11.1 6.1 | 4.3 39.7 300 16 8 9.2 5.1 8250 3.6 38.5 265 14 7 10.1 5.5 | 5.0 41.0 300 16 8 8.0 4.4 8000 5.0 41.0 265 14 7 9.8 5.4 | 5.6 42.1 300 16 8 8.6 4.7 7750 5.8 42.4 265 13 7 11.5 6.3 | 6.3 43.3 305 15 8 9.8 5.4 7500 6.6 43.9 265 13 7 9.6 5.2 | 7.0 44.6 305 14 7 8.1 4.4 7250 7.3 45.1 265 13 7 7.5 4.1 | 7.5 45.5 305 14 7 6.3 3.5 7000 7.9 46.2 265 13 7 10.5 5.8 | 8.0 46.4 305 14 7 9.0 4.9 6750 8.8 47.8 265 13 6 12.6 6.9 | 8.7 47.7 310 13 6 10.5 5.8 6500 9.7 49.5 265 12 6 10.9 6.0 | 9.5 49.1 310 12 6 9.3 5.1 6250 10.5 50.9 265 12 6 11.4 6.2 | 10.1 50.2 310 12 6 9.7 5.3 6000 11.3 52.3 270 12 6 8.2 4.5 | 10.8 51.4 310 12 6 7.7 4.2 5750 11.9 53.4 265 11 6 12.3 6.7 | 11.4 52.5 315 10 5 9.7 5.3 5500 14.8 58.6 270 10 5 86.6 47.5 | 13.3 55.9 310 9 5 53.1 29.1 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 ________________________________________________________________________________ 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