Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
949 UXUS97 KGJT 051307 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 707 AM MDT Sunday, May 5, 2024 This forecast is for Sunday, May 5, 2024: If the trigger temperature of 68.2 F/20.1 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 912 ft/min (4.6 m/s) Maximum height of thermals.................. 16945 ft MSL (12106 ft AGL) Forecast maximum temperature................... 76.0 F/24.9 C Time of trigger temperature.................... 0945 MDT Time of overdevelopment........................ None Middle/high clouds during soaring window....... Broken/overcast thin middle Surface winds during soaring window............ Between 20 mph and 30 mph Height of the -3 thermal index................. 10075 ft MSL (5236 ft AGL) Thermal soaring outlook for Monday 05/06....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:10:11 / 20:11:22 MDT Total possible sunshine........... 14 hr 1 min 11 sec (841 min 11 sec) Altitude of sun at 13:10:47 MDT... 67.32 degrees Upper air data from rawinsonde observation taken on 05/05/2024 at 0600 MDT Freezing level.................. 12479 ft MSL (7640 ft AGL) Convective condensation level... 16290 ft MSL (11451 ft AGL) Lifted condensation level....... 16547 ft MSL (11708 ft AGL) Lifted index.................... +3.3 K index......................... +1.4 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 -58.6 -73.5 240 42 21 1.4 0.8 101.4 214.5 44.1 M M 45000 -59.7 -75.5 235 39 20 -5.6 -3.1 75.1 167.1 31.0 M M 40000 -63.5 -82.3 235 56 29 6.4 3.5 46.0 114.9 14.2 M M 38000 -59.2 -74.6 240 53 28 7.6 4.2 43.6 110.5 13.0 M M 36000 -54.1 -65.4 250 54 28 9.0 4.9 42.5 108.5 12.5 M M 34000 -47.8 -54.0 245 52 27 9.2 5.1 42.1 107.7 12.6 M M 32000 -43.5 -46.3 225 46 24 7.0 3.8 39.9 103.9 11.4 M M 30000 -38.5 -37.3 225 44 23 8.7 4.8 38.9 102.1 10.9 M M 29000 -35.8 -32.4 225 49 25 8.8 4.8 38.6 101.4 10.7 M M 28000 -33.2 -27.8 225 50 26 8.9 4.9 38.2 100.7 10.5 M M 27000 -30.9 -23.6 225 53 27 7.7 4.2 37.5 99.5 10.1 M M 26000 -28.6 -19.5 230 54 28 7.7 4.2 36.7 98.1 9.6 M M 25000 -26.3 -15.3 225 53 27 7.7 4.2 35.9 96.6 9.1 M M 24000 -23.9 -11.0 230 52 27 8.0 4.4 35.2 95.4 8.6 M M 23000 -21.6 -6.9 225 47 24 7.7 4.2 34.5 94.1 8.1 M M 22000 -19.2 -2.6 230 46 24 8.5 4.6 33.8 92.9 7.6 M M 21000 -16.7 1.9 230 43 22 7.3 4.0 33.4 92.1 7.3 M M 20000 -15.3 4.5 220 44 22 5.5 3.0 32.1 89.7 6.2 M M 19500 -14.1 6.6 215 50 26 -4.1 -2.3 31.3 88.4 5.6 M M 19000 -16.5 2.3 210 54 28 -3.9 -2.1 26.8 80.2 1.8 M M 18500 -14.5 5.9 215 48 25 9.7 5.3 26.5 79.7 1.6 M M 18000 -13.4 7.9 220 46 24 6.7 3.7 26.1 79.0 1.3 M M 17500 -12.7 9.1 225 49 25 2.9 1.6 25.2 77.4 0.5 M M 17000 -11.8 10.8 225 51 26 8.1 4.5 24.6 76.2 -0.0 1107 5.6 16500 -10.6 12.9 225 48 25 8.3 4.6 24.3 75.7 -0.3 1056 5.4 16000 -9.5 14.9 225 45 23 5.9 3.2 23.8 74.8 -0.7 1011 5.1 15500 -8.3 17.1 225 42 22 9.5 5.2 23.5 74.4 -1.0 959 4.9 15000 -6.9 19.6 230 42 22 9.3 5.1 23.5 74.2 -1.0 903 4.6 14500 -5.5 22.1 225 43 22 9.3 5.1 23.4 74.1 -1.1 847 4.3 14000 -4.2 24.4 225 40 21 9.3 5.1 23.3 73.9 -1.2 791 4.0 13500 -2.8 27.0 230 41 21 9.3 5.1 23.2 73.8 -1.3 735 3.7 13000 -1.4 29.5 230 42 22 9.4 5.2 23.1 73.6 -1.4 678 3.4 12500 0.0 32.0 225 43 22 9.5 5.2 23.1 73.5 -1.5 620 3.2 12000 1.5 34.7 220 45 23 9.5 5.2 23.1 73.5 -1.5 563 2.9 11500 2.9 37.2 215 45 23 7.9 4.4 23.0 73.4 -1.6 506 2.6 11000 3.8 38.8 210 46 24 6.9 3.8 22.5 72.5 -2.1 462 2.3 10500 4.8 40.6 210 46 24 6.9 3.8 22.0 71.7 -2.6 417 2.1 10250 5.3 41.5 205 42 21 6.9 3.8 21.8 71.3 -2.8 395 2.0 10000 5.8 42.4 200 36 19 7.0 3.8 21.6 70.8 -3.1 373 1.9 9750 6.3 43.3 200 39 20 7.1 3.9 21.4 70.5 -3.3 351 1.8 9500 6.8 44.2 200 37 19 7.1 3.9 21.2 70.1 -3.5 328 1.7 9250 7.3 45.1 195 37 19 7.2 3.9 21.0 69.7 -3.8 305 1.5 9000 7.9 46.2 195 39 20 7.1 3.9 20.8 69.4 -4.0 282 1.4 8750 8.4 47.1 195 38 19 7.5 4.1 20.5 69.0 -4.2 259 1.3 8500 8.9 48.0 195 35 18 8.5 4.7 20.4 68.7 -4.4 235 1.2 8250 9.6 49.3 195 36 18 8.6 4.7 20.3 68.6 -4.5 208 1.1 8000 10.2 50.4 195 34 18 9.5 5.2 20.3 68.5 -4.6 182 0.9 7750 11.0 51.8 195 34 18 9.8 5.4 20.3 68.5 -4.6 152 0.8 7500 11.6 52.9 190 31 16 8.9 4.9 20.2 68.4 -4.6 125 0.6 7250 12.3 54.1 185 29 15 8.8 4.9 20.2 68.3 -4.8 98 0.5 7000 12.9 55.2 175 26 14 8.9 4.9 20.1 68.2 -4.9 72 0.4 6750 13.5 56.3 175 27 14 9.1 5.0 20.0 68.1 -5.0 45 0.2 6500 14.2 57.6 175 29 15 9.2 5.0 20.0 68.0 -5.0 17 0.1 6250 14.9 58.8 180 30 15 9.0 4.9 19.9 67.9 -5.1 M M 6000 15.6 60.1 180 31 16 9.5 5.2 19.9 67.8 -5.1 M M 5750 16.3 61.3 175 29 15 7.7 4.2 19.9 67.7 -5.2 M M 5500 16.7 62.1 175 23 12 5.3 2.9 19.6 67.2 -5.5 M M 5250 17.1 62.8 170 17 9 5.7 3.1 19.2 66.6 -5.9 M M 5000 17.5 63.5 165 11 6 4.6 2.5 18.9 66.1 -6.2 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 05/05/2024 at 0900 MDT | 05/05/2024 at 1200 MDT | CAPE... 0.0 LI... +1.6 | CAPE... +0.4 LI... +2.1 CINH... -0.0 K Index... +9.9 | CINH... -0.2 K Index... +15.7 | 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 -55.6 -68.1 245 31 16 -2.0 -1.1 | -55.4 -67.7 240 27 14 -1.2 -0.7 45000 -58.6 -73.5 245 37 19 -0.6 -0.3 | -57.2 -71.0 235 30 15 -1.1 -0.6 40000 -59.1 -74.4 240 63 33 -0.4 -0.2 | -58.8 -73.8 235 76 39 -1.1 -0.6 38000 -57.0 -70.6 240 70 36 6.3 3.4 | -57.1 -70.8 235 85 44 6.1 3.3 36000 -52.8 -63.0 240 74 38 6.3 3.4 | -53.0 -63.4 230 86 44 6.1 3.3 34000 -48.7 -55.7 240 74 38 7.9 4.3 | -49.0 -56.2 230 85 44 7.8 4.3 32000 -44.0 -47.2 235 66 34 7.9 4.3 | -44.3 -47.7 230 77 40 7.8 4.3 30000 -39.3 -38.7 235 59 30 7.9 4.3 | -39.6 -39.3 230 71 36 8.0 4.4 29000 -36.9 -34.4 230 58 30 7.9 4.3 | -37.2 -35.0 230 69 36 8.0 4.4 28000 -34.5 -30.1 230 57 29 7.9 4.3 | -34.9 -30.8 225 68 35 8.0 4.4 27000 -32.2 -26.0 225 56 29 7.6 4.2 | -32.5 -26.5 225 66 34 7.7 4.2 26000 -30.0 -22.0 225 57 29 7.5 4.1 | -30.2 -22.4 225 64 33 7.5 4.1 25000 -27.8 -18.0 225 57 29 7.5 4.1 | -28.0 -18.4 225 62 32 7.6 4.1 24000 -25.5 -13.9 225 57 30 7.4 4.1 | -25.8 -14.4 220 60 31 7.5 4.1 23000 -23.6 -10.5 225 57 29 6.4 3.5 | -23.7 -10.7 220 59 30 6.9 3.8 22000 -21.3 -6.3 220 56 29 6.4 3.5 | -21.1 -6.0 220 59 30 6.9 3.8 21000 -19.4 -2.9 220 55 28 5.6 3.1 | -19.1 -2.4 220 58 30 6.4 3.5 20000 -17.7 0.1 220 53 27 5.6 3.1 | -17.3 0.9 220 56 29 6.4 3.5 19500 -16.9 1.6 220 52 27 5.6 3.1 | -16.3 2.7 215 55 28 6.4 3.5 19000 -16.0 3.2 215 52 27 5.6 3.1 | -15.4 4.3 215 54 28 6.4 3.5 18500 -15.2 4.6 215 51 26 6.4 3.5 | -14.5 5.9 215 53 27 6.2 3.4 18000 -14.2 6.4 215 50 26 6.7 3.7 | -13.6 7.5 215 52 27 6.0 3.3 17500 -13.2 8.2 215 50 26 6.8 3.7 | -12.7 9.1 215 51 26 6.0 3.3 17000 -12.1 10.2 210 49 25 7.3 4.0 | -11.8 10.8 210 51 26 6.0 3.3 16500 -11.0 12.2 210 49 25 7.3 4.0 | -10.9 12.4 210 50 26 5.9 3.3 16000 -9.9 14.2 210 48 25 7.5 4.1 | -9.9 14.2 210 49 25 6.8 3.7 15500 -8.8 16.2 210 47 24 7.5 4.1 | -8.9 16.0 210 48 25 6.9 3.8 15000 -7.7 18.1 210 46 24 7.6 4.2 | -7.9 17.8 210 48 25 7.0 3.8 14500 -6.5 20.3 210 45 23 7.6 4.2 | -6.8 19.8 210 47 24 7.1 3.9 14000 -5.4 22.3 210 43 22 7.6 4.2 | -5.8 21.6 205 47 24 7.2 3.9 13500 -4.3 24.3 210 43 22 7.8 4.3 | -4.6 23.7 205 46 24 7.7 4.2 13000 -3.1 26.4 210 43 22 7.8 4.3 | -3.5 25.7 205 45 23 7.7 4.2 12500 -2.0 28.4 210 44 22 7.8 4.3 | -2.3 27.9 200 44 23 8.2 4.5 12000 -0.8 30.6 210 44 23 7.8 4.3 | -1.2 29.8 200 43 22 8.1 4.4 11500 0.3 32.5 210 45 23 7.4 4.0 | 0.1 32.2 200 42 22 8.8 4.8 11000 1.3 34.3 210 44 23 7.5 4.1 | 1.4 34.5 195 41 21 8.8 4.8 10500 2.4 36.3 205 43 22 7.0 3.8 | 2.6 36.7 195 40 21 8.4 4.6 10250 2.9 37.2 205 43 22 7.5 4.1 | 3.3 37.9 195 40 21 9.6 5.2 10000 3.5 38.3 205 42 22 8.0 4.4 | 4.1 39.4 195 40 20 11.0 6.0 9750 4.0 39.2 200 42 22 8.6 4.7 | 4.9 40.8 195 39 20 10.2 5.6 9500 4.7 40.5 200 41 21 9.0 4.9 | 5.6 42.1 195 39 20 9.8 5.4 9250 5.3 41.5 200 40 20 9.0 4.9 | 6.3 43.3 195 39 20 9.9 5.4 9000 5.9 42.6 195 39 20 7.2 3.9 | 7.1 44.8 195 38 20 10.0 5.5 8750 6.4 43.5 195 38 20 7.9 4.3 | 7.8 46.0 195 38 19 10.1 5.5 8500 7.1 44.8 195 37 19 9.6 5.3 | 8.6 47.5 195 37 19 10.0 5.5 8250 8.5 47.3 190 36 18 7.9 4.4 | 9.3 48.7 195 37 19 10.1 5.5 8000 9.0 48.2 190 34 18 7.7 4.2 | 10.8 51.4 195 35 18 10.1 5.6 7750 9.7 49.5 190 33 17 9.2 5.1 | 11.6 52.9 195 34 18 10.0 5.5 7500 10.4 50.7 185 32 16 9.3 5.1 | 12.3 54.1 195 33 17 10.6 5.8 7250 11.0 51.8 185 30 16 7.5 4.1 | 13.1 55.6 195 32 17 8.4 4.6 7000 11.5 52.7 180 29 15 7.8 4.3 | 13.7 56.7 195 33 17 8.8 4.8 6750 12.2 54.0 180 27 14 9.9 5.4 | 14.5 58.1 195 31 16 11.3 6.2 6500 12.9 55.2 180 25 13 9.7 5.3 | 15.3 59.5 195 30 15 10.7 5.9 6250 13.7 56.7 180 24 12 10.6 5.8 | 16.1 61.0 190 28 14 11.4 6.3 6000 14.6 58.3 175 23 12 13.4 7.4 | 17.1 62.8 190 28 15 16.1 8.8 5750 15.7 60.3 175 20 10 17.4 9.5 | 18.5 65.3 190 25 13 23.0 12.6 5500 16.8 62.2 175 17 9 10.5 5.7 | 20.0 68.0 190 21 11 10.9 6.0 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 05/05/2024 at 1500 MDT | 05/05/2024 at 1800 MDT | CAPE... +2.1 LI... +1.7 | CAPE... +3.6 LI... +0.6 CINH... -0.3 K Index... +19.4 | CINH... -1.9 K Index... +23.7 | 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 -54.7 -66.5 240 23 12 -0.6 -0.3 | -54.5 -66.1 235 20 10 -0.1 -0.1 45000 -55.7 -68.3 235 29 15 -1.7 -0.9 | -54.7 -66.5 225 25 13 -1.4 -0.7 40000 -58.5 -73.3 230 77 40 -1.9 -1.0 | -57.4 -71.3 225 77 39 -1.8 -1.0 38000 -56.7 -70.1 230 88 45 5.9 3.3 | -56.0 -68.8 225 91 47 5.2 2.8 36000 -53.1 -63.6 225 90 46 5.9 3.3 | -52.9 -63.2 225 97 50 5.2 2.8 34000 -49.2 -56.6 225 90 46 8.0 4.4 | -49.4 -56.9 220 100 52 7.5 4.1 32000 -44.3 -47.7 225 85 44 8.1 4.4 | -44.9 -48.8 220 94 48 7.6 4.2 30000 -39.5 -39.1 225 80 41 7.9 4.4 | -40.2 -40.4 220 88 45 8.1 4.5 29000 -37.1 -34.8 220 78 40 7.9 4.3 | -37.8 -36.0 220 86 44 8.2 4.5 28000 -34.8 -30.6 220 76 39 7.9 4.3 | -35.3 -31.5 215 84 43 8.2 4.5 27000 -32.4 -26.3 220 75 38 7.8 4.3 | -32.9 -27.2 215 82 42 8.0 4.4 26000 -30.1 -22.2 220 74 38 7.7 4.2 | -30.7 -23.3 215 81 42 7.4 4.0 25000 -27.9 -18.2 220 73 37 7.7 4.2 | -28.5 -19.3 215 79 41 7.4 4.1 24000 -25.6 -14.1 220 72 37 7.7 4.2 | -26.3 -15.3 215 78 40 7.5 4.1 23000 -23.0 -9.4 220 69 36 6.9 3.8 | -23.7 -10.7 215 74 38 6.9 3.8 22000 -20.9 -5.6 220 67 35 7.0 3.8 | -21.6 -6.9 215 70 36 6.9 3.8 21000 -18.9 -2.0 220 65 33 6.3 3.4 | -19.6 -3.3 215 66 34 6.6 3.6 20000 -17.1 1.2 215 61 31 6.2 3.4 | -17.7 0.1 210 62 32 6.5 3.6 19500 -16.2 2.8 215 59 30 6.2 3.4 | -16.7 1.9 210 59 31 6.5 3.6 19000 -15.2 4.6 215 57 29 6.2 3.4 | -15.8 3.6 210 58 30 6.5 3.6 18500 -14.3 6.3 215 56 29 6.4 3.5 | -14.8 5.4 205 56 29 6.5 3.6 18000 -13.4 7.9 215 54 28 6.6 3.6 | -13.9 7.0 205 55 28 6.6 3.6 17500 -12.4 9.7 215 53 27 6.6 3.6 | -12.9 8.8 205 54 28 6.6 3.6 17000 -11.4 11.5 210 52 27 6.5 3.6 | -12.0 10.4 205 53 27 6.6 3.6 16500 -10.5 13.1 210 51 26 6.6 3.6 | -11.0 12.2 200 52 27 6.6 3.6 16000 -9.5 14.9 210 50 26 6.5 3.6 | -10.0 14.0 200 51 26 6.8 3.7 15500 -8.6 16.5 205 49 25 6.5 3.6 | -9.0 15.8 200 51 26 7.0 3.8 15000 -7.6 18.3 205 48 25 6.8 3.8 | -8.0 17.6 200 50 26 7.0 3.8 14500 -6.5 20.3 205 48 25 7.4 4.1 | -7.0 19.4 200 49 25 7.2 3.9 14000 -5.4 22.3 200 47 24 7.5 4.1 | -5.9 21.4 200 48 25 7.1 3.9 13500 -4.2 24.4 200 47 24 8.7 4.8 | -4.8 23.4 200 47 24 8.1 4.5 13000 -2.9 26.8 200 46 24 8.5 4.7 | -3.6 25.5 200 47 24 8.0 4.4 12500 -1.6 29.1 200 46 24 9.4 5.1 | -2.4 27.7 200 46 24 8.8 4.8 12000 -0.2 31.6 200 46 24 9.3 5.1 | -1.1 30.0 200 46 24 8.7 4.8 11500 1.2 34.2 200 46 24 9.4 5.2 | 0.3 32.5 200 45 23 9.5 5.2 11000 2.6 36.7 200 46 24 9.5 5.2 | 1.7 35.1 200 45 23 9.7 5.3 10500 3.9 39.0 200 46 24 7.9 4.4 | 3.1 37.6 200 44 23 8.5 4.7 10250 4.6 40.3 200 46 24 9.5 5.2 | 3.8 38.8 200 44 23 9.6 5.3 10000 5.4 41.7 200 45 23 11.1 6.1 | 4.6 40.3 200 43 22 10.9 6.0 9750 6.1 43.0 200 45 23 10.2 5.6 | 5.4 41.7 200 42 22 10.4 5.7 9500 6.9 44.4 200 45 23 9.7 5.3 | 6.1 43.0 200 42 22 10.1 5.5 9250 7.6 45.7 200 45 23 9.8 5.4 | 6.9 44.4 200 42 21 9.9 5.4 9000 8.4 47.1 200 44 23 10.0 5.5 | 7.6 45.7 200 41 21 9.4 5.2 8750 9.1 48.4 200 43 22 10.1 5.5 | 8.3 46.9 200 40 20 9.5 5.2 8500 10.6 51.1 200 43 22 10.1 5.5 | 9.8 49.6 200 39 20 10.2 5.6 8250 11.4 52.5 200 43 22 9.9 5.4 | 10.5 50.9 200 39 20 9.5 5.2 8000 12.1 53.8 200 40 21 10.0 5.5 | 11.2 52.2 200 36 19 8.9 4.9 7750 12.9 55.2 200 39 20 10.1 5.5 | 11.8 53.2 195 36 18 9.2 5.0 7500 13.6 56.5 200 38 20 10.4 5.7 | 12.5 54.5 195 36 18 8.9 4.9 7250 14.4 57.9 200 37 19 8.9 4.9 | 13.2 55.8 195 35 18 9.7 5.3 7000 15.0 59.0 200 39 20 9.2 5.1 | 14.0 57.2 195 31 16 9.9 5.4 6750 15.8 60.4 200 36 19 11.1 6.1 | 14.7 58.5 195 30 15 9.5 5.2 6500 16.6 61.9 200 34 17 10.2 5.6 | 15.4 59.7 195 28 15 9.1 5.0 6250 17.4 63.3 200 31 16 11.8 6.5 | 16.1 61.0 195 27 14 11.0 6.0 6000 18.4 65.1 200 33 17 16.8 9.2 | 17.0 62.6 195 28 15 13.3 7.3 5750 19.8 67.6 200 29 15 20.6 11.3 | 17.9 64.2 195 24 12 11.1 6.1 5500 21.2 70.2 200 25 13 15.1 8.3 | 18.8 65.8 195 20 10 16.7 9.2 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