Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
551 UXUS97 KGJT 191308 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 708 AM MDT Wednesday, June 19, 2024 This forecast is for Wednesday, June 19, 2024: If the trigger temperature of 76.3 F/24.6 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1380 ft/min (7.0 m/s) Maximum height of thermals.................. 20179 ft MSL (15350 ft AGL) Forecast maximum temperature................... 92.0 F/33.8 C Time of trigger temperature.................... 1030 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................. 19137 ft MSL (14308 ft AGL) Thermal soaring outlook for Thursday 06/20..... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:48:07 / 20:43:16 MDT Total possible sunshine........... 14 hr 55 min 9 sec (895 min 9 sec) Altitude of sun at 13:15:41 MDT... 73.97 degrees Upper air data from rawinsonde observation taken on 06/19/2024 at 0600 MDT Freezing level.................. 14290 ft MSL (9461 ft AGL) Convective condensation level... 21981 ft MSL (17152 ft AGL) Lifted condensation level....... 21544 ft MSL (16714 ft AGL) Lifted index.................... +1.1 K index......................... +10.9 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 -56.2 -69.2 225 58 30 3.8 2.1 102.7 216.9 40.0 M M 45000 -52.6 -62.7 230 59 30 -1.0 -0.5 84.4 183.9 31.5 M M 40000 -57.1 -70.8 230 78 40 -9.0 -4.9 53.5 128.3 13.3 M M 38000 -55.0 -67.0 225 74 38 5.9 3.3 47.8 118.0 9.8 M M 36000 -50.7 -59.3 230 70 36 7.9 4.4 45.6 114.1 8.6 M M 34000 -45.2 -49.4 230 68 35 9.7 5.3 45.1 113.3 8.4 M M 32000 -39.9 -39.8 235 66 34 8.6 4.7 44.3 111.7 8.0 M M 30000 -35.5 -31.9 225 69 35 6.1 3.4 42.3 108.2 6.7 M M 29000 -32.5 -26.5 230 65 33 8.1 4.4 41.6 106.8 6.3 M M 28000 -30.2 -22.4 225 60 31 7.3 4.0 40.8 105.4 5.7 M M 27000 -28.0 -18.4 225 60 31 8.4 4.6 39.9 103.7 5.1 M M 26000 -25.5 -13.9 225 57 29 8.1 4.4 39.3 102.8 4.7 M M 25000 -23.4 -10.1 225 53 27 6.6 3.6 38.2 100.8 3.9 M M 24000 -21.6 -6.9 225 52 27 7.6 4.2 36.9 98.4 2.8 M M 23000 -19.1 -2.4 225 51 26 8.3 4.6 36.3 97.4 2.4 M M 22000 -16.8 1.8 220 47 24 6.4 3.5 35.7 96.2 1.9 M M 21000 -14.9 5.2 225 44 23 6.6 3.6 34.4 94.0 0.9 M M 20000 -13.0 8.6 225 45 23 3.8 2.1 33.2 91.8 -0.2 1371 7.0 19500 -12.3 9.9 220 46 24 -5.6 -3.1 32.3 90.2 -1.0 1336 6.8 19000 -13.0 8.6 210 45 23 15.0 8.2 30.1 86.2 -3.1 1340 6.8 18500 -11.3 11.7 210 45 23 9.0 4.9 30.4 86.8 -2.9 1275 6.5 18000 -9.8 14.4 215 40 21 8.2 4.5 30.5 87.0 -2.9 1216 6.2 17500 -8.5 16.7 220 39 20 8.4 4.6 30.4 86.7 -3.1 1163 5.9 17000 -7.3 18.9 215 37 19 8.5 4.6 30.2 86.3 -3.2 1110 5.6 16500 -6.0 21.2 215 35 18 8.5 4.6 30.0 86.0 -3.4 1057 5.4 16000 -4.1 24.6 215 29 15 8.5 4.6 29.7 85.5 -3.7 978 5.0 15500 -2.8 27.0 210 30 15 8.5 4.6 29.5 85.1 -3.9 926 4.7 15000 -1.6 29.1 210 29 15 8.5 4.6 29.3 84.7 -4.1 873 4.4 14500 -0.3 31.5 210 27 14 8.5 4.6 29.1 84.3 -4.3 820 4.2 14000 1.0 33.8 215 26 13 8.5 4.6 28.9 83.9 -4.5 767 3.9 13500 2.2 36.0 225 23 12 8.5 4.6 28.6 83.5 -4.8 715 3.6 13000 3.5 38.3 230 18 9 8.5 4.6 28.4 83.1 -5.0 662 3.4 12500 4.8 40.6 225 17 9 8.5 4.6 28.1 82.7 -5.3 609 3.1 12000 6.0 42.8 215 15 8 8.5 4.7 27.9 82.2 -5.5 556 2.8 11500 7.4 45.3 210 13 7 8.6 4.7 27.7 81.9 -5.7 502 2.5 11000 8.7 47.7 220 11 6 8.6 4.7 27.5 81.5 -5.8 447 2.3 10500 9.9 49.8 230 9 5 6.5 3.6 27.3 81.1 -6.1 395 2.0 10250 10.4 50.7 235 8 4 5.8 3.2 27.0 80.5 -6.4 375 1.9 10000 10.8 51.4 235 8 4 6.6 3.6 26.7 80.1 -6.7 354 1.8 9750 11.3 52.3 200 7 4 6.3 3.5 26.4 79.6 -7.0 333 1.7 9500 11.7 53.1 180 8 4 7.0 3.9 26.2 79.1 -7.3 312 1.6 9250 12.2 54.0 165 10 5 4.5 2.5 25.9 78.7 -7.5 291 1.5 9000 12.4 54.3 165 8 4 2.8 1.5 25.4 77.7 -8.1 277 1.4 8750 12.7 54.9 165 7 3 5.4 3.0 25.0 76.9 -8.5 260 1.3 8500 13.2 55.8 150 5 3 6.0 3.3 24.6 76.4 -8.8 239 1.2 8250 13.6 56.5 130 4 2 5.9 3.2 24.3 75.8 -9.1 218 1.1 8000 14.1 57.4 100 4 2 5.7 3.1 24.1 75.3 -9.4 198 1.0 7750 14.3 57.7 100 5 3 -1.5 -0.8 23.5 74.4 -9.9 183 0.9 7500 14.1 57.4 085 6 3 -0.0 -0.0 22.5 72.6 -10.9 183 0.9 7250 14.4 57.9 075 7 4 6.7 3.7 22.2 71.9 -11.3 165 0.8 7000 14.9 58.8 080 9 5 6.9 3.8 21.9 71.5 -11.6 144 0.7 6750 15.5 59.9 085 9 5 8.1 4.5 21.8 71.2 -11.8 119 0.6 6500 16.0 60.8 095 8 4 7.4 4.0 21.6 70.9 -12.0 94 0.5 6250 16.6 61.9 100 6 3 9.2 5.0 21.5 70.7 -12.1 70 0.4 6000 17.2 63.0 090 4 2 2.7 1.5 21.3 70.4 -12.3 45 0.2 5750 17.1 62.8 085 4 2 -0.5 -0.3 20.5 68.9 -13.1 39 0.2 5500 17.3 63.1 080 4 2 2.9 1.6 19.9 67.9 -13.7 26 0.1 5250 17.4 63.3 060 3 2 -1.1 -0.6 19.3 66.7 -14.4 17 0.1 5000 17.2 63.0 260 1 1 -2.7 -1.5 18.4 65.1 -15.4 15 0.1 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/19/2024 at 0900 MDT | 06/19/2024 at 1200 MDT | CAPE... 0.0 LI... +2.0 | CAPE... +2.9 LI... +1.1 CINH... -0.0 K Index... +19.4 | CINH... -0.9 K Index... +19.3 | 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 -57.5 -71.5 225 50 26 2.0 1.1 | -58.6 -73.5 225 53 27 1.5 0.8 45000 -55.1 -67.2 235 53 27 -0.1 -0.0 | -56.5 -69.7 225 54 28 0.8 0.4 40000 -55.0 -67.0 255 44 23 4.9 2.7 | -54.8 -66.6 255 50 26 8.1 4.5 38000 -51.4 -60.5 250 46 24 6.0 3.3 | -50.3 -58.5 255 50 26 7.4 4.1 36000 -47.8 -54.0 245 48 25 6.0 3.3 | -45.9 -50.6 250 50 26 7.4 4.1 34000 -43.9 -47.0 240 50 26 6.9 3.8 | -41.6 -42.9 250 50 26 7.0 3.8 32000 -39.7 -39.5 230 54 28 6.9 3.8 | -37.4 -35.3 240 50 26 7.0 3.8 30000 -35.3 -31.5 225 55 29 7.8 4.3 | -33.6 -28.5 235 50 26 6.2 3.4 29000 -32.9 -27.2 225 55 28 7.8 4.3 | -31.7 -25.1 230 50 26 6.2 3.4 28000 -30.6 -23.1 230 54 28 7.8 4.3 | -29.9 -21.8 230 51 26 6.1 3.4 27000 -28.4 -19.1 225 53 27 7.1 3.9 | -27.4 -17.3 225 49 25 6.8 3.7 26000 -26.3 -15.3 225 51 26 7.1 3.9 | -25.3 -13.5 225 48 25 6.8 3.7 25000 -23.6 -10.5 225 49 25 7.0 3.9 | -23.3 -9.9 220 47 24 6.8 3.7 24000 -21.4 -6.5 220 48 25 7.7 4.2 | -21.1 -6.0 220 45 23 7.4 4.1 23000 -19.0 -2.2 220 46 24 7.7 4.2 | -18.9 -2.0 220 43 22 7.4 4.1 22000 -16.7 1.9 220 44 23 7.8 4.3 | -16.6 2.1 220 41 21 7.4 4.1 21000 -14.6 5.7 215 43 22 6.8 3.8 | -14.5 5.9 220 39 20 7.0 3.8 20000 -12.6 9.3 215 41 21 6.9 3.8 | -12.4 9.7 215 38 19 7.0 3.9 19500 -11.6 11.1 215 40 20 6.9 3.8 | -11.4 11.5 215 37 19 7.1 3.9 19000 -10.6 12.9 215 39 20 6.6 3.6 | -10.4 13.3 215 36 19 6.9 3.8 18500 -9.6 14.7 210 38 20 6.6 3.6 | -9.4 15.1 215 35 18 6.9 3.8 18000 -8.7 16.3 210 38 19 6.7 3.7 | -8.4 16.9 210 34 18 6.9 3.8 17500 -7.7 18.1 210 37 19 7.3 4.0 | -7.3 18.9 210 33 17 7.3 4.0 17000 -6.7 19.9 210 36 19 7.3 4.0 | -6.3 20.7 210 32 16 7.2 4.0 16500 -5.6 21.9 210 35 18 7.9 4.4 | -5.2 22.6 210 31 16 8.1 4.5 16000 -4.5 23.9 210 33 17 8.1 4.5 | -4.0 24.8 205 30 15 8.3 4.6 15500 -3.3 26.1 205 32 16 8.4 4.6 | -2.8 27.0 205 28 15 8.5 4.7 15000 -2.0 28.4 205 30 16 8.7 4.8 | -1.6 29.1 205 27 14 8.8 4.8 14500 -0.7 30.7 205 29 15 8.7 4.8 | -0.3 31.5 205 26 13 8.8 4.8 14000 0.6 33.1 205 28 14 9.0 5.0 | 1.0 33.8 205 25 13 8.9 4.9 13500 1.9 35.4 205 27 14 9.0 5.0 | 2.3 36.1 205 24 12 8.8 4.9 13000 3.3 37.9 205 25 13 8.8 4.8 | 3.7 38.7 205 22 12 9.4 5.2 12500 4.6 40.3 205 24 12 8.9 4.9 | 5.1 41.2 205 21 11 9.4 5.1 12000 5.9 42.6 205 22 11 8.3 4.6 | 6.5 43.7 205 20 11 9.2 5.1 11500 7.2 45.0 205 20 10 8.3 4.6 | 7.9 46.2 205 19 10 9.3 5.1 11000 8.3 46.9 205 18 9 6.6 3.6 | 9.2 48.6 200 18 9 7.6 4.2 10500 9.3 48.7 205 16 8 5.5 3.0 | 10.3 50.5 200 16 8 7.4 4.1 10250 9.8 49.6 205 15 8 9.6 5.3 | 10.9 51.6 200 16 8 11.0 6.0 10000 10.6 51.1 200 13 7 9.4 5.2 | 11.8 53.2 200 15 7 10.7 5.9 9750 11.1 52.0 195 12 6 5.1 2.8 | 12.5 54.5 200 14 7 7.8 4.3 9500 11.5 52.7 195 11 6 6.7 3.7 | 13.1 55.6 200 12 6 9.0 4.9 9250 12.0 53.6 190 11 5 4.7 2.6 | 14.2 57.6 195 10 5 7.8 4.3 9000 12.3 54.1 180 11 5 4.4 2.4 | 14.9 58.8 195 10 5 9.7 5.3 8750 12.7 54.9 175 10 5 5.7 3.1 | 15.6 60.1 195 9 5 9.2 5.1 8500 13.5 56.3 160 8 4 4.9 2.7 | 16.3 61.3 195 8 4 9.3 5.1 8250 13.8 56.8 155 9 5 4.3 2.4 | 17.0 62.6 190 8 4 9.7 5.3 8000 14.2 57.6 150 8 4 4.8 2.6 | 17.8 64.0 190 7 4 10.1 5.6 7750 14.5 58.1 145 7 4 5.0 2.7 | 18.5 65.3 195 7 4 10.2 5.6 7500 14.9 58.8 140 6 3 3.6 2.0 | 19.3 66.7 195 7 3 8.9 4.9 7250 15.1 59.2 140 7 3 3.1 1.7 | 19.9 67.8 190 6 3 8.5 4.6 7000 15.4 59.7 140 7 3 6.9 3.8 | 20.6 69.1 190 6 3 10.9 6.0 6750 16.0 60.8 130 5 3 8.8 4.8 | 21.5 70.7 195 6 3 11.7 6.4 6500 16.6 61.9 125 5 3 7.9 4.3 | 22.3 72.1 195 5 3 10.7 5.9 6250 17.2 63.0 125 5 2 7.8 4.3 | 23.1 73.6 190 5 3 11.3 6.2 6000 17.8 64.0 125 4 2 8.9 4.9 | 23.9 75.0 190 5 2 7.5 4.1 5750 18.7 65.7 125 4 2 15.7 8.6 | 24.4 75.9 200 5 2 12.3 6.7 5500 20.4 68.7 120 4 2 32.7 18.0 | 27.6 81.7 185 4 2 94.1 51.7 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 06/19/2024 at 1500 MDT | 06/19/2024 at 1800 MDT | CAPE... +3.3 LI... +0.2 | CAPE... +4.1 LI... +0.3 CINH... -5.3 K Index... +19.1 | CINH... -1.6 K Index... +17.9 | 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 -59.0 -74.2 225 56 29 0.8 0.4 | -58.8 -73.8 225 54 28 0.0 0.0 45000 -57.5 -71.5 225 61 31 1.4 0.8 | -58.1 -72.6 225 65 33 1.8 1.0 40000 -54.8 -66.6 235 54 28 8.0 4.4 | -55.0 -67.0 220 61 31 7.8 4.3 38000 -50.3 -58.5 235 54 28 7.4 4.1 | -50.6 -59.1 225 60 31 7.4 4.0 36000 -45.8 -50.4 235 55 28 7.4 4.1 | -45.6 -50.1 225 59 30 7.4 4.0 34000 -41.2 -42.2 235 53 27 7.9 4.3 | -41.0 -41.8 225 57 29 7.8 4.3 32000 -36.5 -33.7 235 51 26 7.9 4.3 | -36.3 -33.3 230 56 29 7.8 4.3 30000 -32.2 -26.0 235 50 26 6.6 3.6 | -31.7 -25.1 230 53 27 7.5 4.1 29000 -30.3 -22.5 230 49 25 6.6 3.6 | -29.5 -21.1 230 52 27 7.5 4.1 28000 -27.8 -18.0 230 49 25 6.4 3.5 | -27.2 -17.0 230 51 26 7.5 4.1 27000 -26.0 -14.8 225 48 25 6.1 3.3 | -25.4 -13.7 225 49 25 5.5 3.0 26000 -24.2 -11.6 220 47 24 6.1 3.3 | -23.8 -10.8 225 48 25 5.6 3.1 25000 -22.4 -8.3 220 46 24 6.0 3.3 | -22.1 -7.8 220 46 24 5.6 3.1 24000 -20.3 -4.5 215 45 23 7.0 3.8 | -20.4 -4.7 220 44 23 6.3 3.5 23000 -18.2 -0.8 215 43 22 7.0 3.8 | -18.5 -1.3 215 42 22 6.4 3.5 22000 -16.1 3.0 215 41 21 7.0 3.8 | -16.1 3.0 215 40 21 6.5 3.6 21000 -14.2 6.4 215 38 19 6.5 3.5 | -14.2 6.4 210 35 18 7.0 3.8 20000 -12.3 9.9 210 34 17 6.6 3.6 | -12.1 10.2 210 31 16 7.1 3.9 19500 -11.4 11.5 210 32 17 6.5 3.6 | -11.1 12.0 205 28 15 7.0 3.8 19000 -10.4 13.3 210 31 16 7.9 4.3 | -10.0 14.0 205 26 14 8.4 4.6 18500 -9.2 15.4 210 29 15 8.1 4.5 | -8.8 16.2 205 25 13 8.4 4.6 18000 -8.0 17.6 205 27 14 8.3 4.5 | -7.6 18.3 205 24 13 8.6 4.7 17500 -6.8 19.8 205 26 13 8.8 4.8 | -6.2 20.8 205 24 12 9.1 5.0 17000 -5.5 22.1 205 25 13 8.7 4.8 | -4.9 23.2 205 23 12 9.0 5.0 16500 -4.2 24.4 205 24 13 9.1 5.0 | -3.5 25.7 205 23 12 9.7 5.3 16000 -2.8 27.0 205 24 12 9.2 5.0 | -2.1 28.2 205 22 11 9.6 5.3 15500 -1.4 29.5 205 23 12 9.2 5.0 | -0.6 30.9 205 22 11 9.5 5.2 15000 -0.1 31.8 205 22 12 9.2 5.1 | 0.8 33.4 205 21 11 9.4 5.2 14500 1.3 34.3 205 22 11 9.2 5.1 | 2.2 36.0 205 20 10 9.4 5.1 14000 2.7 36.9 205 21 11 9.1 5.0 | 3.6 38.5 205 20 10 9.3 5.1 13500 4.0 39.2 205 20 10 9.1 5.0 | 5.0 41.0 210 19 10 9.3 5.1 13000 5.4 41.7 205 19 10 9.1 5.0 | 6.4 43.5 210 18 9 9.2 5.1 12500 6.8 44.2 210 18 9 9.1 5.0 | 7.8 46.0 215 18 9 9.2 5.1 12000 8.1 46.6 210 17 9 9.3 5.1 | 9.1 48.4 215 17 9 9.3 5.1 11500 9.5 49.1 215 16 8 9.4 5.1 | 10.5 50.9 220 16 8 9.5 5.2 11000 10.8 51.4 215 14 7 8.1 4.4 | 11.8 53.2 220 15 8 7.9 4.3 10500 12.0 53.6 220 13 7 8.6 4.7 | 13.0 55.4 225 14 7 9.1 5.0 10250 12.8 55.0 225 13 6 11.5 6.3 | 13.8 56.8 225 14 7 11.4 6.2 10000 13.7 56.7 225 13 7 11.0 6.0 | 14.6 58.3 230 14 7 9.9 5.4 9750 15.1 59.2 230 13 6 9.8 5.4 | 15.3 59.5 230 13 7 8.7 4.8 9500 15.8 60.4 230 12 6 9.3 5.1 | 15.9 60.6 235 13 7 9.2 5.0 9250 16.5 61.7 235 11 6 9.7 5.3 | 16.6 61.9 235 13 7 8.5 4.6 9000 17.3 63.1 235 12 6 10.3 5.6 | 17.2 63.0 240 12 6 8.8 4.8 8750 18.0 64.4 235 12 6 10.3 5.6 | 17.9 64.2 240 12 6 9.6 5.3 8500 18.8 65.8 235 12 6 9.7 5.3 | 18.7 65.7 245 12 6 9.4 5.2 8250 19.5 67.1 240 11 6 9.6 5.3 | 20.1 68.2 250 12 6 9.5 5.2 8000 20.3 68.5 240 11 6 10.2 5.6 | 20.8 69.4 250 12 6 9.7 5.3 7750 21.0 69.8 240 11 6 10.2 5.6 | 21.5 70.7 250 12 6 9.8 5.4 7500 21.8 71.2 245 11 6 9.4 5.2 | 22.2 72.0 250 12 6 9.1 5.0 7250 22.4 72.3 245 11 6 9.1 5.0 | 22.9 73.2 255 12 6 9.0 4.9 7000 23.2 73.8 250 11 5 10.4 5.7 | 23.6 74.5 255 12 6 10.2 5.6 6750 24.0 75.2 250 11 6 10.9 6.0 | 24.4 75.9 255 11 6 10.7 5.9 6500 24.8 76.6 250 11 5 11.1 6.1 | 25.2 77.4 255 11 6 10.7 5.9 6250 25.7 78.3 250 10 5 12.1 6.7 | 26.0 78.8 260 11 6 11.3 6.2 6000 26.5 79.7 255 10 5 7.8 4.3 | 26.8 80.2 260 11 6 8.1 4.4 5750 27.1 80.8 255 10 5 12.8 7.0 | 27.3 81.1 260 10 5 9.8 5.4 5500 30.4 86.7 260 9 5 98.0 53.8 | 29.5 85.1 265 9 5 61.9 34.0 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 ________________________________________________________________________________ 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