Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
402 UXUS97 KPUB 261254 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0652 MDT Thursday, September 26, 2024 This forecast is for Thursday, September 26, 2024: If the trigger temperature of 75.7 F/24.3 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1044 ft/min (5.3 m/s) Maximum height of thermals.................. 18768 ft MSL (11148 ft AGL) Forecast maximum temperature................... 86.0 F/30.5 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................. 16846 ft MSL (9226 ft AGL) Thermal soaring outlook for Friday 09/27....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:51:27 / 18:49:16 MDT Total possible sunshine........... 11 hr 57 min 49 sec (717 min 49 sec) Altitude of sun at 12:50:21 MDT... 49.30 degrees Upper air data from numerical model forecast valid on 09/26/2024 at 0600 MDT Freezing level.................. 16393 ft MSL (8773 ft AGL) Convective condensation level... 19580 ft MSL (11960 ft AGL) Lifted condensation level....... 19305 ft MSL (11685 ft AGL) Lifted index.................... -1.2 K index......................... +7.1 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 -65.7 -86.3 265 18 9 2.8 1.5 M M M M M 45000 -60.3 -76.5 260 22 11 5.2 2.9 M M M M M 40000 -51.7 -61.1 235 27 14 6.4 3.5 M M M M M 38000 -47.9 -54.2 220 28 14 6.4 3.5 M M M M M 36000 -44.0 -47.2 210 30 15 7.0 3.8 M M M M M 34000 -39.4 -38.9 210 27 14 7.8 4.3 M M M M M 32000 -34.7 -30.5 215 24 13 7.9 4.3 M M M M M 30000 -29.5 -21.1 220 23 12 8.7 4.8 38.8 101.9 6.9 M M 29000 -26.9 -16.4 220 22 11 8.7 4.8 38.5 101.3 6.7 M M 28000 -24.3 -11.7 225 21 11 8.4 4.6 38.2 100.7 6.6 M M 27000 -21.8 -7.2 225 20 10 8.4 4.6 37.6 99.6 6.1 M M 26000 -19.2 -2.6 225 19 10 8.4 4.6 37.1 98.7 5.8 M M 25000 -16.7 1.9 225 17 9 8.3 4.6 36.7 98.0 5.5 M M 24000 -13.7 7.3 225 15 8 8.0 4.4 35.8 96.5 4.9 M M 23000 -11.3 11.7 225 14 7 8.0 4.4 35.2 95.4 4.4 M M 22000 -9.0 15.8 225 13 6 6.2 3.4 34.6 94.3 4.0 M M 21000 -7.3 18.9 235 13 7 5.7 3.2 33.1 91.6 2.7 M M 20000 -5.6 21.9 245 14 7 5.8 3.2 31.8 89.2 1.5 M M 19500 -4.7 23.5 250 14 7 5.6 3.1 31.2 88.1 1.0 M M 19000 -3.9 25.0 250 14 7 5.0 2.7 30.4 86.7 0.3 M M 18500 -3.2 26.2 250 14 7 5.1 2.8 29.6 85.3 -0.5 1020 5.2 18000 -2.5 27.5 250 14 7 4.9 2.7 28.8 83.9 -1.2 984 5.0 17500 -1.8 28.8 245 13 7 5.0 2.8 28.0 82.4 -2.0 949 4.8 17000 -1.1 30.0 245 11 6 5.6 3.1 27.2 81.0 -2.8 914 4.6 16500 -0.2 31.6 240 10 5 7.5 4.1 26.7 80.1 -3.4 872 4.4 16000 0.8 33.4 235 8 4 7.4 4.0 26.3 79.4 -3.8 826 4.2 15500 2.0 35.6 230 7 3 9.3 5.1 26.1 79.0 -4.2 776 3.9 15000 3.3 37.9 230 6 3 9.4 5.2 26.0 78.9 -4.3 721 3.7 14500 4.7 40.5 230 5 2 9.2 5.0 26.0 78.8 -4.4 666 3.4 14000 6.0 42.8 235 4 2 9.0 4.9 25.9 78.5 -4.6 612 3.1 13500 7.3 45.1 245 4 2 9.1 5.0 25.7 78.3 -4.8 558 2.8 13000 8.7 47.7 260 4 2 9.2 5.0 25.7 78.2 -4.9 502 2.5 12500 10.0 50.0 280 4 2 8.8 4.8 25.5 78.0 -5.1 447 2.3 12000 11.3 52.3 300 4 2 8.5 4.7 25.4 77.6 -5.3 395 2.0 11750 11.9 53.4 305 5 3 8.7 4.8 25.3 77.5 -5.4 369 1.9 11500 12.5 54.5 310 6 3 9.0 4.9 25.2 77.3 -5.5 342 1.7 11250 13.1 55.6 310 6 3 8.4 4.6 25.1 77.2 -5.6 316 1.6 11000 13.7 56.7 305 6 3 8.0 4.4 25.0 77.0 -5.8 291 1.5 10750 14.3 57.7 305 6 3 7.5 4.1 24.8 76.7 -5.9 266 1.4 10500 14.9 58.8 305 6 3 9.8 5.4 24.7 76.5 -6.1 241 1.2 10250 15.7 60.3 305 7 3 9.6 5.3 24.8 76.6 -6.1 210 1.1 10000 16.3 61.3 305 7 3 7.2 3.9 24.6 76.3 -6.2 185 0.9 9750 16.8 62.2 300 7 4 7.8 4.3 24.5 76.1 -6.4 161 0.8 9500 17.4 63.3 300 7 4 7.7 4.2 24.3 75.8 -6.6 136 0.7 9250 17.9 64.2 300 7 4 5.9 3.2 24.1 75.4 -6.8 113 0.6 9000 18.3 64.9 295 8 4 4.9 2.7 23.8 74.8 -7.2 95 0.5 8750 18.7 65.7 295 9 5 5.7 3.1 23.4 74.2 -7.5 75 0.4 8500 19.1 66.4 290 10 5 5.5 3.0 23.1 73.6 -7.9 56 0.3 8250 19.3 66.7 290 10 5 -4.1 -2.2 22.6 72.6 -8.5 44 0.2 8000 18.1 64.6 285 10 5 -30.4 -16.7 20.6 69.1 -10.4 72 0.4 7750 14.8 58.6 280 9 5 -52.5 -28.8 16.6 61.9 -14.4 162 0.8 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 * * * * * * 09/26/2024 at 0900 MDT | 09/26/2024 at 1200 MDT | CAPE... 0.0 LI... +2.2 | CAPE... +0.4 LI... +2.6 CINH... 0.0 K Index... +8.8 | CINH... -3.4 K Index... +10.1 | 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 -65.2 -85.4 275 21 11 3.3 1.8 | -64.9 -84.8 270 27 14 3.5 1.9 45000 -59.4 -74.9 270 27 14 5.1 2.8 | -58.7 -73.7 265 37 19 4.8 2.6 40000 -51.1 -60.0 260 31 16 6.0 3.3 | -51.1 -60.0 265 40 21 6.3 3.4 38000 -47.6 -53.7 240 30 15 6.0 3.3 | -47.4 -53.3 255 36 18 6.3 3.4 36000 -44.0 -47.2 220 32 17 6.5 3.5 | -43.6 -46.5 240 33 17 6.3 3.4 34000 -39.4 -38.9 225 31 16 7.7 4.2 | -38.9 -38.0 235 31 16 7.0 3.8 32000 -34.8 -30.6 225 30 15 7.7 4.2 | -34.8 -30.6 230 28 15 7.4 4.1 30000 -29.7 -21.5 225 27 14 8.6 4.7 | -29.6 -21.3 235 24 13 8.7 4.8 29000 -27.1 -16.8 225 25 13 8.6 4.7 | -27.0 -16.6 240 23 12 8.7 4.8 28000 -24.5 -12.1 225 24 12 8.2 4.5 | -24.5 -12.1 245 21 11 8.4 4.6 27000 -22.1 -7.8 230 22 11 8.1 4.4 | -22.0 -7.6 245 22 11 8.4 4.6 26000 -19.7 -3.5 230 21 11 8.1 4.4 | -19.4 -2.9 250 23 12 8.4 4.6 25000 -16.6 2.1 235 19 10 8.0 4.4 | -16.9 1.6 255 23 12 8.0 4.4 24000 -14.2 6.4 235 18 9 8.0 4.4 | -14.7 5.5 250 23 12 7.3 4.0 23000 -11.8 10.8 235 17 9 8.0 4.4 | -12.5 9.5 250 23 12 7.3 4.0 22000 -9.5 14.9 235 16 8 6.2 3.4 | -10.4 13.3 245 22 12 7.1 3.9 21000 -7.8 18.0 240 14 7 5.7 3.2 | -8.3 17.1 245 20 11 6.9 3.8 20000 -6.1 21.0 250 13 7 5.8 3.2 | -5.8 21.6 245 18 9 6.9 3.8 19500 -5.2 22.6 255 13 7 5.7 3.1 | -4.8 23.4 245 17 9 6.4 3.5 19000 -4.4 24.1 260 12 6 5.2 2.9 | -4.0 24.8 245 15 8 5.5 3.0 18500 -3.6 25.5 265 12 6 5.3 2.9 | -3.2 26.2 250 13 7 5.6 3.1 18000 -2.9 26.8 265 12 6 5.2 2.9 | -2.4 27.7 250 12 6 4.6 2.5 17500 -2.2 28.0 265 10 5 5.4 3.0 | -1.8 28.8 250 10 5 4.7 2.6 17000 -1.5 29.3 265 9 5 5.8 3.2 | -1.2 29.8 250 8 4 5.1 2.8 16500 -0.6 30.9 270 8 4 7.0 3.8 | -0.5 31.1 250 6 3 5.9 3.2 16000 0.3 32.5 275 6 3 7.0 3.9 | 0.3 32.5 255 4 2 5.8 3.2 15500 1.4 34.5 285 5 2 9.3 5.1 | 1.3 34.3 265 3 1 9.0 4.9 15000 2.8 37.0 300 4 2 9.3 5.1 | 2.6 36.7 285 2 1 8.7 4.8 14500 4.2 39.6 310 4 2 9.1 5.0 | 3.9 39.0 310 2 1 8.8 4.8 14000 5.5 41.9 320 5 2 9.0 4.9 | 5.1 41.2 335 2 1 8.8 4.9 13500 6.9 44.4 325 5 3 9.2 5.1 | 6.4 43.5 350 3 1 8.6 4.7 13000 8.3 46.9 335 6 3 9.3 5.1 | 7.6 45.7 005 4 2 8.3 4.5 12500 9.4 48.9 340 6 3 7.8 4.3 | 8.8 47.8 360 5 3 8.1 4.5 12000 10.7 51.3 350 7 3 9.4 5.2 | 10.1 50.2 350 6 3 8.4 4.6 11750 11.4 52.5 355 7 4 8.5 4.7 | 10.7 51.3 345 7 4 8.9 4.9 11500 11.9 53.4 360 7 4 6.4 3.5 | 11.4 52.5 345 8 4 9.8 5.4 11250 12.4 54.3 360 8 4 6.9 3.8 | 12.1 53.8 340 8 4 9.4 5.2 11000 13.0 55.4 360 9 4 7.9 4.4 | 12.8 55.0 340 8 4 9.2 5.0 10750 13.5 56.3 360 9 5 8.0 4.4 | 13.5 56.3 340 9 4 9.0 4.9 10500 14.1 57.4 360 10 5 6.8 3.7 | 14.2 57.6 340 9 5 10.0 5.5 10250 14.6 58.3 360 11 5 6.4 3.5 | 15.0 59.0 340 9 5 10.6 5.8 10000 15.1 59.2 360 11 6 7.4 4.0 | 15.7 60.3 340 9 5 9.9 5.4 9750 15.6 60.1 360 12 6 7.4 4.1 | 16.5 61.7 340 9 5 10.5 5.8 9500 16.2 61.2 355 12 6 6.3 3.4 | 17.2 63.0 340 9 5 8.8 4.8 9250 16.6 61.9 355 13 6 4.5 2.5 | 17.8 64.0 340 9 5 9.2 5.0 9000 16.9 62.4 350 12 6 5.5 3.0 | 18.6 65.5 340 9 5 11.5 6.3 8750 17.4 63.3 350 12 6 6.3 3.4 | 19.5 67.1 340 9 5 11.4 6.3 8500 17.8 64.0 345 12 6 6.2 3.4 | 20.3 68.5 340 9 5 10.8 5.9 8250 18.3 64.9 340 12 6 6.7 3.7 | 21.1 70.0 340 9 4 10.4 5.7 8000 18.7 65.7 330 11 6 5.2 2.9 | 22.0 71.6 340 8 4 16.3 9.0 7750 18.9 66.0 320 8 4 2.5 1.4 | 23.5 74.3 345 8 4 24.7 13.6 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 09/26/2024 at 1500 MDT | 09/26/2024 at 1800 MDT | CAPE... +10.5 LI... +0.6 | CAPE... +3.1 LI... +0.3 CINH... -11.6 K Index... +25.3 | CINH... -23.9 K Index... +27.3 | 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 -64.3 -83.7 270 33 17 3.3 1.8 | -63.4 -82.1 290 30 15 3.5 1.9 45000 -58.2 -72.8 265 48 25 4.9 2.7 | -57.5 -71.5 280 47 24 4.7 2.6 40000 -50.6 -59.1 265 55 29 5.9 3.3 | -50.4 -58.7 270 59 30 4.8 2.6 38000 -47.0 -52.6 255 47 24 5.9 3.3 | -47.6 -53.7 265 52 27 4.8 2.6 36000 -43.5 -46.3 250 40 21 5.9 3.2 | -44.7 -48.5 260 45 23 4.3 2.4 34000 -38.9 -38.0 250 37 19 6.9 3.8 | -39.5 -39.1 255 41 21 8.2 4.5 32000 -34.7 -30.5 250 33 17 7.4 4.0 | -34.6 -30.3 255 37 19 8.3 4.6 30000 -29.5 -21.1 245 28 15 8.8 4.8 | -29.6 -21.3 255 33 17 8.3 4.5 29000 -26.9 -16.4 245 26 13 8.8 4.8 | -27.1 -16.8 255 31 16 8.3 4.5 28000 -24.3 -11.7 245 24 12 8.0 4.4 | -24.7 -12.5 255 29 15 7.4 4.1 27000 -21.9 -7.4 250 23 12 8.0 4.4 | -22.5 -8.5 260 28 14 7.4 4.0 26000 -19.5 -3.1 255 22 11 8.0 4.4 | -20.3 -4.5 265 26 13 7.4 4.0 25000 -17.1 1.2 260 21 11 8.2 4.5 | -18.1 -0.6 275 25 13 7.5 4.1 24000 -14.6 5.7 260 20 10 8.4 4.6 | -15.6 3.9 270 24 12 8.3 4.6 23000 -12.0 10.4 260 20 10 8.4 4.6 | -13.1 8.4 265 23 12 8.3 4.6 22000 -9.5 14.9 260 19 10 7.1 3.9 | -10.6 12.9 260 23 12 7.3 4.0 21000 -8.3 17.1 255 20 10 3.9 2.1 | -9.0 15.8 265 21 11 4.4 2.4 20000 -6.9 19.6 250 22 11 4.1 2.2 | -7.8 18.0 265 20 10 4.8 2.6 19500 -6.4 20.5 250 23 12 4.2 2.3 | -7.2 19.0 265 19 10 5.0 2.7 19000 -5.8 21.6 250 21 11 4.4 2.4 | -6.6 20.1 265 17 9 4.9 2.7 18500 -5.3 22.5 250 19 10 4.6 2.5 | -6.0 21.2 265 13 7 4.8 2.7 18000 -4.6 23.7 250 16 8 6.8 3.7 | -5.2 22.6 270 11 5 7.5 4.1 17500 -3.6 25.5 255 13 7 7.1 3.9 | -4.1 24.6 275 9 5 7.8 4.3 17000 -2.7 27.1 255 9 5 7.5 4.1 | -3.0 26.6 280 8 4 7.7 4.2 16500 -1.5 29.3 260 7 4 8.4 4.6 | -1.8 28.8 285 7 3 7.5 4.1 16000 -0.2 31.6 270 6 3 8.3 4.5 | -0.7 30.7 300 5 3 7.3 4.0 15500 1.1 34.0 285 4 2 9.7 5.3 | 0.6 33.1 320 4 2 9.7 5.3 15000 2.5 36.5 305 4 2 9.5 5.2 | 2.0 35.6 350 4 2 9.5 5.2 14500 4.0 39.2 325 4 2 9.6 5.3 | 3.4 38.1 010 5 3 9.7 5.3 14000 5.4 41.7 345 4 2 9.6 5.3 | 4.9 40.8 025 6 3 9.8 5.4 13500 6.8 44.2 355 5 3 9.7 5.3 | 6.4 43.5 035 7 4 9.7 5.3 13000 8.3 46.9 360 5 3 9.8 5.4 | 7.8 46.0 035 8 4 9.6 5.2 12500 9.8 49.6 005 6 3 9.6 5.2 | 9.2 48.6 035 8 4 9.6 5.3 12000 11.1 52.0 005 6 3 8.1 4.4 | 10.7 51.3 035 9 5 9.3 5.1 11750 11.8 53.2 005 6 3 10.0 5.5 | 11.4 52.5 035 9 5 9.8 5.4 11500 12.6 54.7 010 6 3 12.1 6.6 | 12.1 53.8 040 9 5 10.3 5.6 11250 13.4 56.1 010 6 3 9.8 5.4 | 12.9 55.2 040 9 5 9.3 5.1 11000 14.1 57.4 010 6 3 8.7 4.8 | 13.5 56.3 040 9 5 8.9 4.9 10750 14.8 58.6 010 7 3 8.3 4.5 | 14.2 57.6 040 9 5 8.4 4.6 10500 15.4 59.7 010 7 3 11.2 6.2 | 14.9 58.8 040 9 5 10.6 5.8 10250 16.4 61.5 015 7 4 12.1 6.6 | 15.7 60.3 040 10 5 11.3 6.2 10000 17.1 62.8 015 7 4 9.4 5.2 | 16.5 61.7 040 10 5 9.4 5.2 9750 17.9 64.2 015 7 4 10.7 5.9 | 17.2 63.0 040 10 5 10.4 5.7 9500 18.6 65.5 015 7 4 8.3 4.6 | 18.0 64.4 035 10 5 8.5 4.7 9250 19.2 66.6 015 7 4 8.4 4.6 | 18.5 65.3 035 10 5 8.2 4.5 9000 20.0 68.0 015 7 4 10.9 6.0 | 19.2 66.6 035 10 5 10.2 5.6 8750 20.8 69.4 015 7 4 10.7 5.9 | 20.0 68.0 035 10 5 10.2 5.6 8500 21.6 70.9 020 7 4 10.5 5.8 | 20.8 69.4 035 10 5 10.0 5.5 8250 22.3 72.1 020 7 4 11.1 6.1 | 21.4 70.5 035 10 5 8.6 4.7 8000 23.3 73.9 020 7 4 16.3 8.9 | 21.9 71.4 035 10 5 4.8 2.6 7750 24.8 76.6 020 7 4 22.6 12.4 | 22.1 71.8 035 7 4 0.9 0.5 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