Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
008 UXUS97 KPUB 121219 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0618 MDT Saturday, July 12, 2025 This forecast is for Saturday, July 12, 2025: If the trigger temperature of 67.2 F/19.6 C is reached...then Thermal Soaring Index....................... Fair Maximum rate of lift........................ 223 ft/min (1.1 m/s) Maximum height of thermals.................. 12882 ft MSL (5257 ft AGL) Forecast maximum temperature................... 72.0 F/22.7 C Time of trigger temperature.................... 1145 MDT Time of overdevelopment........................ None 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................. 11429 ft MSL (3804 ft AGL) Thermal soaring outlook for Sunday 07/13....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:44:24 / 20:25:39 MDT Total possible sunshine........... 14 hr 41 min 15 sec (881 min 15 sec) Altitude of sun at 13:05:01 MDT... 72.83 degrees Upper air data from numerical model forecast valid on 07/12/2025 at 0600 MDT Freezing level.................. 15760 ft MSL (8135 ft AGL) Convective condensation level... 14133 ft MSL (6508 ft AGL) Lifted condensation level....... 13690 ft MSL (6065 ft AGL) Lifted index.................... -4.9 K index......................... +25.2 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 -60.1 -76.2 280 24 12 1.9 1.0 M M M M M 45000 -57.5 -71.5 270 31 16 1.3 0.7 M M M M M 40000 -55.1 -67.2 255 23 12 6.9 3.8 M M M M M 38000 -50.8 -59.4 270 20 10 6.3 3.5 M M M M M 36000 -47.0 -52.6 285 20 10 6.2 3.4 M M M M M 34000 -42.5 -44.5 290 18 9 7.7 4.2 M M M M M 32000 -37.9 -36.2 300 16 8 7.7 4.2 M M M M M 30000 -33.0 -27.4 315 16 8 8.2 4.5 35.5 95.8 10.3 M M 29000 -30.5 -22.9 325 16 8 8.2 4.5 34.9 94.8 10.0 M M 28000 -28.1 -18.6 335 17 9 8.1 4.5 34.5 94.1 9.8 M M 27000 -25.7 -14.3 340 18 9 8.1 4.4 33.7 92.7 9.3 M M 26000 -23.2 -9.8 340 19 10 8.1 4.4 33.1 91.6 8.9 M M 25000 -20.8 -5.4 340 20 10 8.3 4.6 32.6 90.7 8.6 M M 24000 -18.8 -1.8 340 21 11 6.2 3.4 31.4 88.6 7.7 M M 23000 -16.5 2.3 335 21 11 6.2 3.4 29.8 85.7 6.5 M M 22000 -14.6 5.7 330 22 11 6.6 3.6 28.7 83.7 5.5 M M 21000 -12.7 9.1 330 23 12 6.9 3.8 27.6 81.7 4.6 M M 20000 -10.7 12.7 330 25 13 7.0 3.9 26.6 80.0 3.7 M M 19500 -9.7 14.5 325 26 13 7.4 4.1 26.2 79.2 3.3 M M 19000 -8.5 16.7 330 26 13 8.9 4.9 26.0 78.8 3.0 M M 18500 -7.2 19.0 330 27 14 8.8 4.8 25.8 78.5 2.8 M M 18000 -5.9 21.4 330 27 14 8.8 4.8 25.7 78.2 2.7 M M 17500 -4.7 23.5 330 27 14 8.8 4.8 25.5 77.9 2.5 M M 17000 -3.4 25.9 330 27 14 9.0 4.9 25.4 77.6 2.3 M M 16500 -2.0 28.4 330 26 13 9.5 5.2 25.3 77.5 2.2 M M 16000 -0.7 30.7 330 25 13 9.6 5.3 25.2 77.4 2.2 M M 15500 0.6 33.1 330 23 12 8.3 4.6 25.1 77.2 2.0 M M 15000 1.8 35.2 335 21 11 8.4 4.6 24.9 76.8 1.7 M M 14500 3.0 37.4 335 19 10 8.2 4.5 24.7 76.4 1.5 M M 14000 4.2 39.6 335 17 9 8.0 4.4 24.4 75.9 1.2 M M 13500 5.4 41.7 335 15 8 7.2 3.9 24.1 75.4 0.9 M M 13000 6.1 43.0 330 12 6 5.8 3.2 23.5 74.3 0.2 M M 12500 6.9 44.4 320 10 5 5.1 2.8 22.9 73.2 -0.5 397 2.0 12000 7.3 45.1 315 9 5 2.5 1.4 21.9 71.4 -1.5 370 1.9 11750 7.5 45.5 310 8 4 2.7 1.5 21.3 70.4 -2.1 358 1.8 11500 7.6 45.7 305 8 4 2.7 1.5 20.8 69.4 -2.7 346 1.8 11250 7.8 46.0 300 8 4 1.6 0.9 20.2 68.4 -3.3 334 1.7 11000 7.8 46.0 305 7 4 1.0 0.6 19.5 67.1 -4.0 325 1.6 10750 7.9 46.2 305 7 3 0.5 0.3 18.8 65.9 -4.7 316 1.6 10500 7.9 46.2 305 6 3 3.4 1.8 18.2 64.7 -5.3 307 1.6 10250 8.3 46.9 320 6 3 4.6 2.5 17.8 64.1 -5.7 290 1.5 10000 8.5 47.3 325 6 3 2.7 1.5 17.3 63.1 -6.3 276 1.4 9750 8.7 47.7 335 6 3 2.9 1.6 16.8 62.2 -6.8 262 1.3 9500 8.9 48.0 340 5 3 3.8 2.1 16.3 61.3 -7.3 248 1.3 9250 9.2 48.6 350 6 3 4.8 2.7 15.9 60.6 -7.7 231 1.2 9000 9.5 49.1 350 6 3 3.9 2.2 15.5 59.8 -8.2 215 1.1 8750 9.7 49.5 355 7 3 3.2 1.8 15.0 59.0 -8.8 201 1.0 8500 9.9 49.8 360 7 4 4.3 2.4 14.5 58.1 -9.3 188 1.0 8250 10.3 50.5 360 7 4 5.7 3.1 14.2 57.5 -9.7 170 0.9 8000 10.7 51.3 360 8 4 6.9 3.8 13.9 57.0 -10.1 151 0.8 7750 11.2 52.2 360 7 4 9.3 5.1 13.8 56.8 -10.3 127 0.6 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 * * * * * * 07/12/2025 at 0900 MDT | 07/12/2025 at 1200 MDT | CAPE... +898.3 LI... -2.6 | CAPE... +1831.7 LI... -4.5 CINH... -55.9 K Index... +24.5 | CINH... -14.7 K Index... +19.8 | 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 -60.1 -76.2 280 17 9 2.0 1.1 | -60.4 -76.7 270 18 9 1.0 0.6 45000 -57.3 -71.1 280 22 12 1.6 0.9 | -58.6 -73.5 275 23 12 1.7 0.9 40000 -54.2 -65.6 290 18 9 5.3 2.9 | -55.6 -68.1 305 18 9 6.4 3.5 38000 -50.9 -59.6 305 18 9 5.5 3.0 | -51.5 -60.7 315 18 9 6.0 3.3 36000 -47.6 -53.7 320 19 10 5.1 2.8 | -47.9 -54.2 325 19 10 5.9 3.2 34000 -42.8 -45.0 330 19 10 8.4 4.6 | -42.9 -45.2 325 18 9 8.6 4.7 32000 -37.7 -35.9 340 18 9 8.4 4.6 | -37.8 -36.0 325 17 9 8.5 4.7 30000 -32.6 -26.7 345 18 10 8.5 4.6 | -32.5 -26.5 335 17 9 8.8 4.9 29000 -30.1 -22.2 350 19 10 8.5 4.6 | -29.8 -21.6 340 17 9 8.8 4.9 28000 -27.6 -17.7 350 20 10 8.1 4.5 | -27.2 -17.0 345 18 9 8.3 4.5 27000 -25.2 -13.4 350 20 10 7.8 4.3 | -24.8 -12.6 345 18 9 8.0 4.4 26000 -22.9 -9.2 350 20 10 7.8 4.3 | -22.4 -8.3 345 18 9 8.0 4.4 25000 -20.5 -4.9 350 19 10 7.8 4.3 | -20.0 -4.0 345 18 9 8.0 4.4 24000 -18.2 -0.8 345 20 10 7.7 4.2 | -17.7 0.1 345 18 9 7.6 4.2 23000 -15.3 4.5 340 21 11 7.7 4.2 | -15.4 4.3 345 18 9 7.6 4.2 22000 -13.0 8.6 340 22 11 6.2 3.4 | -13.2 8.2 340 18 9 7.3 4.0 21000 -11.4 11.5 335 22 12 5.5 3.0 | -10.8 12.6 335 21 11 6.1 3.4 20000 -9.8 14.4 330 23 12 5.6 3.1 | -9.0 15.8 335 23 12 6.2 3.4 19500 -9.0 15.8 325 24 12 5.9 3.2 | -8.1 17.4 330 24 12 6.0 3.3 19000 -8.1 17.4 325 25 13 6.8 3.7 | -7.3 18.9 330 25 13 5.6 3.1 18500 -7.1 19.2 320 26 13 7.0 3.8 | -6.5 20.3 325 26 14 5.7 3.1 18000 -6.1 21.0 320 26 14 8.7 4.8 | -5.6 21.9 325 27 14 8.2 4.5 17500 -4.8 23.4 320 25 13 9.0 5.0 | -4.4 24.1 320 26 13 8.6 4.7 17000 -3.5 25.7 320 24 12 8.9 4.9 | -3.2 26.2 315 25 13 9.0 5.0 16500 -2.2 28.0 325 22 11 8.4 4.6 | -1.9 28.6 315 23 12 9.3 5.1 16000 -1.0 30.2 325 19 10 8.4 4.6 | -0.6 30.9 315 21 11 9.4 5.2 15500 0.3 32.5 330 17 9 9.1 5.0 | 0.8 33.4 315 18 9 8.6 4.7 15000 1.7 35.1 330 16 8 9.1 5.0 | 2.1 35.8 320 16 8 8.7 4.8 14500 3.0 37.4 335 15 8 8.8 4.8 | 3.4 38.1 320 14 7 8.1 4.4 14000 4.2 39.6 335 14 7 8.7 4.8 | 4.5 40.1 325 13 7 8.0 4.4 13500 5.5 41.9 335 13 7 7.3 4.0 | 5.7 42.3 330 11 6 7.7 4.3 13000 6.2 43.2 330 12 6 5.1 2.8 | 6.8 44.2 325 11 6 7.5 4.1 12500 7.3 45.1 320 11 5 8.6 4.7 | 8.2 46.8 325 11 5 9.4 5.2 12000 7.8 46.0 315 9 5 2.9 1.6 | 8.9 48.0 320 9 5 4.5 2.4 11750 8.0 46.4 310 8 4 3.2 1.8 | 9.2 48.6 315 9 4 5.6 3.1 11500 8.2 46.8 305 8 4 3.7 2.1 | 9.6 49.3 315 8 4 6.5 3.6 11250 8.4 47.1 305 7 4 0.1 0.1 | 9.9 49.8 310 7 4 0.8 0.4 11000 8.2 46.8 300 6 3 -2.5 -1.4 | 9.7 49.5 300 6 3 -2.5 -1.4 10750 8.0 46.4 295 6 3 -3.0 -1.6 | 9.5 49.1 285 5 3 -2.7 -1.5 10500 7.8 46.0 285 5 2 1.6 0.9 | 9.2 48.6 260 4 2 1.7 0.9 10250 8.1 46.6 285 4 2 4.8 2.6 | 9.6 49.3 250 4 2 5.5 3.0 10000 8.2 46.8 280 3 2 2.4 1.3 | 9.8 49.6 215 4 2 3.8 2.1 9750 8.4 47.1 270 2 1 2.8 1.5 | 10.0 50.0 190 5 2 4.1 2.3 9500 8.6 47.5 250 1 1 3.7 2.0 | 10.2 50.4 175 6 3 4.9 2.7 9250 8.9 48.0 200 1 0 5.3 2.9 | 10.6 51.1 170 7 4 8.4 4.6 9000 9.3 48.7 150 1 1 5.2 2.8 | 11.3 52.3 165 8 4 10.8 5.9 8750 9.6 49.3 135 2 1 4.4 2.4 | 12.1 53.8 160 8 4 11.2 6.1 8500 9.9 49.8 125 3 1 6.5 3.5 | 12.9 55.2 155 9 5 10.5 5.8 8250 10.5 50.9 120 2 1 9.1 5.0 | 13.6 56.5 150 10 5 10.4 5.7 8000 11.1 52.0 110 2 1 8.1 4.4 | 14.4 57.9 150 10 5 10.6 5.8 7750 11.7 53.1 100 2 1 10.2 5.6 | 15.3 59.5 150 10 5 18.2 10.0 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 07/12/2025 at 1500 MDT | 07/12/2025 at 1800 MDT | CAPE... +2156.2 LI... -5.5 | CAPE... +1747.3 LI... -3.8 CINH... -8.2 K Index... +28.0 | CINH... -6.5 K Index... +27.7 | 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 -59.8 -75.6 275 16 8 1.6 0.9 | -60.5 -76.9 275 15 8 1.6 0.9 45000 -57.7 -71.9 290 22 11 0.7 0.4 | -58.5 -73.3 280 19 10 0.5 0.3 40000 -55.6 -68.1 300 23 12 6.7 3.7 | -56.2 -69.2 280 31 16 8.3 4.6 38000 -51.5 -60.7 300 23 12 6.8 3.8 | -51.2 -60.2 290 33 17 8.4 4.6 36000 -47.4 -53.3 305 24 13 6.7 3.7 | -46.1 -51.0 295 35 18 8.4 4.6 34000 -42.5 -44.5 310 24 12 8.2 4.5 | -41.2 -42.2 305 32 17 8.2 4.5 32000 -37.6 -35.7 315 23 12 8.2 4.5 | -36.2 -33.2 315 30 16 8.1 4.5 30000 -32.6 -26.7 320 22 11 8.4 4.6 | -31.5 -24.7 320 28 14 7.9 4.3 29000 -30.1 -22.2 320 21 11 8.4 4.6 | -29.1 -20.4 325 27 14 7.9 4.3 28000 -27.6 -17.7 325 21 11 8.2 4.5 | -26.8 -16.2 335 26 13 7.7 4.2 27000 -25.1 -13.2 325 21 11 8.1 4.5 | -24.5 -12.1 335 25 13 7.5 4.1 26000 -22.7 -8.9 330 21 11 8.1 4.5 | -22.3 -8.1 340 25 13 7.5 4.1 25000 -20.3 -4.5 330 22 11 8.1 4.5 | -19.5 -3.1 345 24 12 7.7 4.2 24000 -17.3 0.9 330 21 11 8.0 4.4 | -17.2 1.0 340 24 12 7.8 4.3 23000 -14.9 5.2 330 20 10 8.1 4.4 | -14.9 5.2 340 23 12 7.9 4.3 22000 -12.5 9.5 330 20 10 6.7 3.7 | -12.6 9.3 340 23 12 7.8 4.3 21000 -10.8 12.6 325 23 12 6.3 3.5 | -10.3 13.5 340 23 12 7.8 4.3 20000 -9.0 15.8 325 25 13 6.6 3.6 | -8.1 17.4 340 24 12 7.9 4.3 19500 -8.1 17.4 325 27 14 7.0 3.8 | -6.9 19.6 340 24 12 7.5 4.1 19000 -7.0 19.4 320 27 14 8.1 4.5 | -6.1 21.0 340 23 12 5.5 3.0 18500 -5.9 21.4 320 26 13 8.1 4.5 | -5.3 22.5 345 22 11 5.6 3.1 18000 -4.8 23.4 320 25 13 7.8 4.3 | -4.4 24.1 345 20 10 6.7 3.7 17500 -3.7 25.3 320 23 12 7.7 4.2 | -3.4 25.9 345 18 9 7.0 3.8 17000 -2.5 27.5 320 21 11 7.5 4.1 | -2.4 27.7 350 16 8 6.8 3.8 16500 -1.5 29.3 325 19 10 6.7 3.7 | -1.5 29.3 350 14 7 5.8 3.2 16000 -0.5 31.1 330 18 9 6.6 3.6 | -0.7 30.7 355 13 6 5.8 3.2 15500 0.6 33.1 335 17 9 8.1 4.5 | 0.2 32.4 360 11 6 7.1 3.9 15000 1.8 35.2 340 16 8 8.1 4.4 | 1.3 34.3 005 10 5 7.1 3.9 14500 3.1 37.6 345 15 8 8.4 4.6 | 2.4 36.3 010 8 4 7.8 4.3 14000 4.4 39.9 350 14 7 8.6 4.7 | 3.7 38.7 015 6 3 8.2 4.5 13500 5.7 42.3 355 12 6 8.4 4.6 | 4.9 40.8 025 5 3 8.5 4.7 13000 6.9 44.4 360 10 5 8.2 4.5 | 6.3 43.3 030 3 2 8.9 4.9 12500 8.2 46.8 005 9 5 8.5 4.7 | 7.4 45.3 025 2 1 7.3 4.0 12000 9.3 48.7 360 8 4 7.2 4.0 | 8.5 47.3 020 1 1 7.7 4.2 11750 9.8 49.6 360 7 4 7.8 4.3 | 9.0 48.2 015 1 1 7.6 4.1 11500 10.4 50.7 360 7 3 7.4 4.1 | 9.5 49.1 355 1 0 5.7 3.1 11250 10.8 51.4 355 6 3 2.5 1.4 | 9.9 49.8 000 0 0 4.2 2.3 11000 10.7 51.3 355 4 2 -0.0 -0.0 | 10.1 50.2 225 1 0 4.3 2.4 10750 10.6 51.1 355 1 1 0.5 0.3 | 10.3 50.5 210 2 1 4.4 2.4 10500 10.5 50.9 195 1 0 2.3 1.3 | 10.6 51.1 205 3 1 4.4 2.4 10250 10.7 51.3 175 3 2 5.2 2.8 | 10.9 51.6 210 4 2 4.9 2.7 10000 11.0 51.8 170 5 3 5.4 2.9 | 11.2 52.2 205 5 2 5.6 3.1 9750 11.2 52.2 165 8 4 5.5 3.0 | 11.5 52.7 200 6 3 5.3 2.9 9500 11.5 52.7 165 10 5 5.5 3.0 | 11.8 53.2 195 7 3 6.2 3.4 9250 11.9 53.4 160 11 6 8.3 4.5 | 12.3 54.1 195 7 4 8.5 4.7 9000 12.7 54.9 160 11 6 10.9 6.0 | 12.9 55.2 195 7 4 9.3 5.1 8750 13.5 56.3 160 11 6 10.9 6.0 | 13.5 56.3 190 8 4 8.8 4.9 8500 14.2 57.6 160 12 6 10.6 5.8 | 14.8 58.6 185 8 4 10.2 5.6 8250 15.0 59.0 155 12 6 10.6 5.8 | 15.6 60.1 185 8 4 11.4 6.3 8000 16.0 60.8 155 12 6 16.9 9.3 | 16.5 61.7 185 7 4 12.7 7.0 7750 17.6 63.7 155 11 6 25.9 14.2 | 17.4 63.3 185 6 3 10.6 5.8 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) 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 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. 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