Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
019 UXUS97 KPUB 141218 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0618 MDT Wednesday, August 14, 2024 This forecast is for the Air Force Academy for Wednesday, August 14, 2024: If the trigger temperature of 70.0 F/21.1 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 490 ft/min (2.5 m/s) Maximum height of thermals.................. 17350 ft MSL (9726 ft AGL) Forecast maximum temperature................... 79.0 F/26.6 C Time of trigger temperature.................... 0915 MDT Time of overdevelopment........................ 1500 MDT Middle/high clouds during soaring window....... Broken/overcast opaque middle Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 14146 ft MSL (6522 ft AGL) Thermal soaring outlook for Thursday 08/15..... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:12:40 / 19:54:59 MDT Total possible sunshine........... 13 hr 42 min 19 sec (822 min 19 sec) Altitude of sun at 13:03:49 MDT... 65.03 degrees Upper air data from numerical model forecast valid on 08/14/2024 at 0600 MDT Freezing level.................. 15889 ft MSL (8265 ft AGL) Convective condensation level... 15673 ft MSL (8049 ft AGL) Lifted condensation level....... 16358 ft MSL (8734 ft AGL) Lifted index.................... -2.0 K index......................... +25.0 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 -63.1 -81.6 230 19 10 2.2 1.2 M M M M M 45000 -57.9 -72.2 230 27 14 5.9 3.2 M M M M M 40000 -49.1 -56.4 235 33 17 5.7 3.1 M M M M M 38000 -45.2 -49.4 235 36 18 5.7 3.1 M M M M M 36000 -41.8 -43.2 230 38 20 6.4 3.5 M M M M M 34000 -37.3 -35.1 225 37 19 7.6 4.1 M M M M M 32000 -32.7 -26.9 225 36 19 7.5 4.1 M M M M M 30000 -28.4 -19.1 225 33 17 7.2 3.9 40.7 105.2 11.3 M M 29000 -26.3 -15.3 225 32 16 7.2 3.9 39.7 103.5 10.7 M M 28000 -24.1 -11.4 225 30 15 7.0 3.9 38.9 102.0 10.1 M M 27000 -22.1 -7.8 230 28 14 7.0 3.8 37.7 99.9 9.3 M M 26000 -20.0 -4.0 235 27 14 7.0 3.8 36.7 98.0 8.5 M M 25000 -17.9 -0.2 240 25 13 7.1 3.9 35.8 96.4 7.8 M M 24000 -16.1 3.0 245 25 13 6.1 3.4 34.5 94.1 6.8 M M 23000 -13.9 7.0 245 24 12 6.2 3.4 32.9 91.1 5.4 M M 22000 -12.1 10.2 250 23 12 6.7 3.7 31.7 89.1 4.4 M M 21000 -10.1 13.8 245 23 12 6.9 3.8 30.6 87.2 3.4 M M 20000 -8.1 17.4 240 23 12 7.0 3.8 29.7 85.5 2.6 M M 19500 -7.1 19.2 240 23 12 7.0 3.8 29.3 84.7 2.1 M M 19000 -6.2 20.8 240 22 11 6.4 3.5 28.8 83.8 1.7 M M 18500 -5.2 22.6 240 21 11 6.4 3.5 28.2 82.7 1.1 M M 18000 -4.3 24.3 240 19 10 6.4 3.5 27.6 81.8 0.6 M M 17500 -3.3 26.1 245 17 9 6.3 3.5 27.1 80.7 0.1 M M 17000 -2.4 27.7 245 15 8 6.4 3.5 26.5 79.7 -0.4 857 4.4 16500 -1.3 29.7 250 13 7 7.7 4.2 26.1 78.9 -0.8 811 4.1 16000 -0.2 31.6 255 10 5 7.7 4.2 25.7 78.3 -1.2 763 3.9 15500 0.8 33.4 260 9 4 6.5 3.6 25.3 77.6 -1.6 717 3.6 15000 1.7 35.1 275 8 4 6.4 3.5 24.8 76.6 -2.1 674 3.4 14500 2.7 36.9 290 7 4 6.6 3.6 24.2 75.6 -2.7 632 3.2 14000 3.7 38.7 305 6 3 6.9 3.8 23.8 74.8 -3.1 586 3.0 13500 4.7 40.5 320 6 3 7.0 3.9 23.3 74.0 -3.6 541 2.7 13000 5.8 42.4 330 7 3 7.6 4.2 23.0 73.3 -3.9 493 2.5 12500 6.9 44.4 335 7 4 8.0 4.4 22.6 72.8 -4.3 445 2.3 12000 8.1 46.6 335 8 4 9.1 5.0 22.5 72.4 -4.6 394 2.0 11750 8.8 47.8 335 9 4 8.8 4.8 22.4 72.3 -4.7 367 1.9 11500 9.4 48.9 335 9 5 7.4 4.1 22.3 72.1 -4.8 342 1.7 11250 9.9 49.8 335 9 5 7.8 4.3 22.1 71.7 -5.0 319 1.6 11000 10.5 50.9 335 10 5 8.7 4.7 22.0 71.6 -5.1 292 1.5 10750 11.2 52.2 330 11 6 8.8 4.8 21.9 71.4 -5.3 266 1.4 10500 11.8 53.2 330 11 6 7.5 4.1 21.8 71.2 -5.4 239 1.2 10250 12.3 54.1 325 13 7 5.8 3.2 21.5 70.8 -5.6 218 1.1 10000 12.7 54.9 320 14 7 6.0 3.3 21.2 70.2 -6.0 199 1.0 9750 13.1 55.6 320 15 8 5.9 3.3 20.9 69.7 -6.3 179 0.9 9500 13.5 56.3 315 16 8 6.0 3.3 20.7 69.2 -6.6 159 0.8 9250 13.9 57.0 315 16 8 6.5 3.6 20.4 68.7 -6.9 138 0.7 9000 14.4 57.9 315 15 8 6.5 3.6 20.1 68.3 -7.2 116 0.6 8750 14.9 58.8 310 15 8 6.4 3.5 19.9 67.8 -7.5 96 0.5 8500 15.3 59.5 305 15 8 6.1 3.3 19.6 67.3 -7.8 75 0.4 8250 15.7 60.3 305 15 8 2.8 1.5 19.3 66.7 -8.2 57 0.3 8000 15.4 59.7 300 14 7 -10.9 -6.0 18.3 65.0 -9.2 56 0.3 7750 13.9 57.0 295 10 5 -27.1 -14.9 16.1 61.0 -11.5 96 0.5 7500 M M M M M M M M M M M M 7250 M M M M M M M M M M M M 7000 M M M M M M M M M M M M 6750 M M M M M M M M M M M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 08/14/2024 at 0900 MDT | 08/14/2024 at 1200 MDT | CAPE... +328.6 LI... -0.4 | CAPE... +319.3 LI... -2.0 CINH... -39.3 K Index... +24.5 | CINH... -0.2 K Index... +26.1 | 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 -63.5 -82.3 240 24 12 2.3 1.3 | -62.7 -80.9 250 24 12 2.7 1.5 45000 -57.7 -71.9 240 29 15 6.7 3.7 | -56.8 -70.2 250 31 16 6.4 3.5 40000 -48.0 -54.4 235 32 16 4.7 2.6 | -47.7 -53.9 250 34 17 3.9 2.2 38000 -44.8 -48.6 235 36 19 4.7 2.6 | -45.1 -49.2 260 35 18 3.9 2.1 36000 -42.0 -43.6 230 40 21 5.4 3.0 | -42.7 -44.9 265 37 19 5.1 2.8 34000 -37.9 -36.2 230 39 20 6.9 3.8 | -38.3 -36.9 265 36 18 7.4 4.1 32000 -33.7 -28.7 230 37 19 7.4 4.1 | -33.9 -29.0 260 35 18 7.5 4.1 30000 -29.4 -20.9 230 33 17 7.3 4.0 | -29.5 -21.1 260 33 17 7.3 4.0 29000 -27.2 -17.0 235 30 16 7.3 4.0 | -27.3 -17.1 260 31 16 7.3 4.0 28000 -25.0 -13.0 235 28 14 7.5 4.1 | -25.1 -13.2 265 30 15 7.6 4.2 27000 -22.7 -8.9 240 26 14 7.6 4.2 | -22.8 -9.0 265 29 15 7.8 4.3 26000 -20.4 -4.7 245 25 13 7.7 4.2 | -20.4 -4.7 265 28 14 7.8 4.3 25000 -18.1 -0.6 250 24 12 7.7 4.2 | -18.1 -0.6 265 27 14 7.8 4.3 24000 -16.1 3.0 255 22 11 6.6 3.6 | -16.0 3.2 265 26 13 6.9 3.8 23000 -14.1 6.6 260 20 11 6.7 3.7 | -13.4 7.9 265 26 13 6.9 3.8 22000 -11.7 10.9 265 19 10 6.6 3.6 | -11.4 11.5 265 25 13 5.5 3.0 21000 -9.8 14.4 275 19 10 6.5 3.6 | -9.9 14.2 270 24 12 5.0 2.8 20000 -7.9 17.8 280 19 10 6.5 3.6 | -8.5 16.7 275 23 12 5.1 2.8 19500 -7.0 19.4 285 20 10 6.3 3.4 | -7.7 18.1 280 23 12 5.4 2.9 19000 -6.3 20.7 285 18 10 4.8 2.6 | -6.9 19.6 280 22 11 6.2 3.4 18500 -5.6 21.9 280 17 9 4.9 2.7 | -6.1 21.0 280 20 10 6.4 3.5 18000 -4.9 23.2 280 15 8 5.9 3.3 | -5.3 22.5 275 19 10 6.3 3.5 17500 -4.0 24.8 275 13 7 6.3 3.4 | -4.4 24.1 280 17 9 6.4 3.5 17000 -3.2 26.2 275 11 6 6.6 3.6 | -3.6 25.5 280 15 8 6.8 3.7 16500 -2.1 28.2 275 10 5 8.0 4.4 | -2.5 27.5 280 13 7 7.9 4.3 16000 -0.9 30.4 280 10 5 8.0 4.4 | -1.3 29.7 280 12 6 8.0 4.4 15500 0.2 32.4 280 9 5 7.2 4.0 | -0.3 31.5 285 11 6 6.5 3.6 15000 1.2 34.2 285 9 5 7.3 4.0 | 0.7 33.3 290 10 5 6.6 3.6 14500 2.3 36.1 295 8 4 7.5 4.1 | 1.8 35.2 295 9 5 8.0 4.4 14000 3.5 38.3 300 8 4 7.6 4.2 | 3.0 37.4 305 8 4 8.6 4.7 13500 4.6 40.3 315 7 4 7.9 4.3 | 4.3 39.7 310 6 3 8.6 4.7 13000 5.9 42.6 325 7 4 8.3 4.6 | 5.4 41.7 325 5 3 9.1 5.0 12500 7.2 45.0 340 8 4 8.7 4.8 | 6.8 44.2 340 5 2 10.7 5.9 12000 8.5 47.3 345 8 4 9.5 5.2 | 8.4 47.1 350 4 2 10.9 6.0 11750 9.2 48.6 350 9 5 8.9 4.9 | 9.2 48.6 355 4 2 10.0 5.5 11500 9.8 49.6 355 9 5 7.5 4.1 | 9.8 49.6 355 4 2 8.5 4.6 11250 10.4 50.7 355 10 5 8.1 4.4 | 10.5 50.9 360 5 2 9.4 5.2 11000 11.0 51.8 355 10 5 9.1 5.0 | 11.2 52.2 360 4 2 10.2 5.6 10750 11.7 53.1 355 10 5 8.8 4.8 | 12.0 53.6 360 4 2 10.5 5.8 10500 12.4 54.3 355 10 5 9.1 5.0 | 12.8 55.0 005 4 2 8.5 4.7 10250 13.0 55.4 355 10 5 8.6 4.7 | 13.3 55.9 005 4 2 8.6 4.7 10000 13.6 56.5 355 10 5 8.0 4.4 | 14.1 57.4 005 4 2 10.6 5.8 9750 14.2 57.6 355 10 5 8.3 4.6 | 14.9 58.8 010 5 2 10.6 5.8 9500 14.8 58.6 350 10 5 7.8 4.3 | 15.6 60.1 010 5 2 8.7 4.8 9250 15.4 59.7 350 9 5 6.8 3.7 | 16.2 61.2 010 5 2 8.6 4.7 9000 15.8 60.4 340 10 5 6.6 3.6 | 17.0 62.6 010 5 2 11.3 6.2 8750 16.3 61.3 330 10 5 7.3 4.0 | 17.8 64.0 015 5 2 11.5 6.3 8500 16.7 62.1 325 11 5 5.5 3.0 | 18.6 65.5 015 5 2 11.0 6.0 8250 16.9 62.4 315 10 5 2.5 1.4 | 19.5 67.1 015 5 2 11.2 6.2 8000 17.0 62.6 305 9 5 7.5 4.1 | 20.5 68.9 020 4 2 17.4 9.5 7750 17.8 64.0 295 8 4 16.9 9.3 | 22.1 71.8 020 4 2 25.7 14.1 7500 M M M M M M M | M M M M M M M 7250 M M M M M M M | M M M M M M M 7000 M M M M M M M | M M M M M M M 6750 M M M M M M M | M M M M M M M 08/14/2024 at 1500 MDT | 08/14/2024 at 1800 MDT | CAPE... +413.4 LI... -2.7 | CAPE... +495.3 LI... -3.0 CINH... -0.3 K Index... +28.8 | CINH... -2.6 K Index... +30.7 | 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 -62.4 -80.3 245 25 13 2.1 1.2 | -62.1 -79.8 255 29 15 1.9 1.0 45000 -57.3 -71.1 245 35 18 5.8 3.2 | -57.2 -71.0 255 42 22 5.7 3.1 40000 -48.7 -55.7 250 47 24 4.8 2.6 | -48.9 -56.0 260 54 28 5.0 2.7 38000 -45.5 -49.9 265 46 24 4.8 2.6 | -45.5 -49.9 275 57 29 5.0 2.7 36000 -42.6 -44.7 280 48 25 5.7 3.1 | -42.5 -44.5 285 62 32 5.7 3.2 34000 -38.3 -36.9 275 46 24 7.3 4.0 | -38.3 -36.9 285 59 30 7.2 3.9 32000 -33.9 -29.0 270 44 23 7.3 4.0 | -33.9 -29.0 285 55 28 7.3 4.0 30000 -29.3 -20.7 270 42 22 7.7 4.2 | -29.5 -21.1 285 52 27 7.4 4.1 29000 -27.0 -16.6 265 41 21 7.7 4.2 | -27.3 -17.1 280 50 26 7.4 4.1 28000 -24.7 -12.5 265 41 21 8.1 4.5 | -25.1 -13.2 280 48 25 7.7 4.2 27000 -22.2 -8.0 265 41 21 8.2 4.5 | -22.7 -8.9 280 46 24 7.8 4.3 26000 -19.7 -3.5 265 41 21 8.2 4.5 | -20.4 -4.7 275 43 22 7.8 4.3 25000 -17.3 0.9 265 41 21 8.1 4.5 | -18.0 -0.4 270 41 21 7.7 4.2 24000 -15.5 4.1 265 38 20 5.3 2.9 | -16.0 3.2 270 40 20 6.4 3.5 23000 -13.5 7.7 265 34 18 5.4 3.0 | -13.7 7.3 265 38 20 6.5 3.6 22000 -11.9 10.6 265 31 16 5.5 3.0 | -11.8 10.8 265 37 19 5.9 3.2 21000 -10.3 13.5 270 29 15 5.7 3.1 | -10.2 13.6 260 33 17 5.8 3.2 20000 -8.7 16.3 270 28 14 5.9 3.3 | -8.6 16.5 255 30 15 6.0 3.3 19500 -7.9 17.8 270 27 14 6.3 3.5 | -7.8 18.0 255 28 14 6.2 3.4 19000 -7.0 19.4 270 26 14 7.3 4.0 | -6.9 19.6 250 26 13 6.7 3.7 18500 -6.0 21.2 270 25 13 7.3 4.0 | -5.9 21.4 250 24 12 6.7 3.7 18000 -5.0 23.0 270 24 12 6.5 3.6 | -5.0 23.0 245 21 11 7.8 4.3 17500 -4.1 24.6 270 20 10 6.3 3.5 | -3.8 25.2 245 19 10 8.0 4.4 17000 -3.2 26.2 265 17 9 6.4 3.5 | -2.6 27.3 245 16 8 7.7 4.2 16500 -2.3 27.9 265 13 7 6.5 3.6 | -1.7 28.9 240 14 7 6.5 3.6 16000 -1.4 29.5 265 9 4 6.4 3.5 | -0.7 30.7 235 11 6 6.5 3.6 15500 -0.4 31.3 265 5 3 7.8 4.3 | 0.2 32.4 225 9 5 6.8 3.7 15000 0.7 33.3 260 3 1 7.7 4.2 | 1.2 34.2 215 8 4 6.8 3.7 14500 1.8 35.2 220 1 0 8.8 4.8 | 2.2 36.0 200 7 4 7.9 4.3 14000 3.1 37.6 155 1 1 9.3 5.1 | 3.4 38.1 195 7 4 8.4 4.6 13500 4.5 40.1 135 2 1 9.6 5.3 | 4.6 40.3 185 7 3 9.2 5.0 13000 6.0 42.8 135 2 1 10.0 5.5 | 6.1 43.0 185 7 3 10.1 5.5 12500 7.4 45.3 135 2 1 10.2 5.6 | 7.6 45.7 185 7 3 10.0 5.5 12000 9.0 48.2 135 2 1 11.3 6.2 | 9.0 48.2 185 7 3 10.3 5.6 11750 9.8 49.6 135 2 1 10.0 5.5 | 9.8 49.6 185 7 3 9.6 5.3 11500 10.5 50.9 135 2 1 7.9 4.4 | 10.5 50.9 180 7 3 8.4 4.6 11250 11.1 52.0 135 3 1 9.4 5.1 | 11.1 52.0 180 7 3 9.4 5.1 11000 11.9 53.4 135 3 1 10.5 5.7 | 11.8 53.2 180 7 3 10.0 5.5 10750 12.7 54.9 135 3 1 10.7 5.9 | 12.6 54.7 180 7 3 10.3 5.7 10500 13.4 56.1 135 3 1 8.7 4.7 | 13.3 55.9 180 7 3 8.6 4.7 10250 14.0 57.2 135 3 1 8.5 4.7 | 13.9 57.0 180 7 3 8.4 4.6 10000 14.8 58.6 135 3 2 10.5 5.8 | 14.6 58.3 175 7 3 10.0 5.5 9750 15.5 59.9 135 3 2 10.2 5.6 | 15.3 59.5 175 7 3 9.7 5.3 9500 16.3 61.3 135 3 2 9.5 5.2 | 16.0 60.8 175 7 3 9.4 5.2 9250 17.0 62.6 135 3 2 9.3 5.1 | 16.7 62.1 175 7 3 9.3 5.1 9000 17.7 63.9 135 3 2 10.3 5.7 | 17.4 63.3 175 7 3 9.9 5.4 8750 18.5 65.3 135 3 2 10.3 5.6 | 18.2 64.8 175 7 3 9.8 5.4 8500 19.2 66.6 130 4 2 10.3 5.7 | 18.9 66.0 175 7 3 10.1 5.6 8250 20.0 68.0 135 4 2 11.2 6.1 | 19.7 67.5 175 7 4 11.2 6.2 8000 20.9 69.6 130 4 2 15.2 8.3 | 20.6 69.1 175 7 3 12.7 7.0 7750 22.2 72.0 130 4 2 20.1 11.0 | 21.5 70.7 170 6 3 13.8 7.6 7500 M M M M M M M | M M M M M M M 7250 M M M M M M M | M M M M M M M 7000 M M M M M M M | M M M M M M M 6750 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). 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 near the Air Force Academy in Colorado Springs, Colorado at North Latitude: 38 deg 58 min 48.000 sec West Longitude: 104 deg 49 min 12.000 sec Elevation: 6572 feet (2003 meters) and may not be representative of other areas along the Front Range of the Colorado Rocky Mountains. 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. CIN (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