Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
945 UXUS97 KPUB 301218 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0618 MDT Tuesday, April 30, 2024 This forecast is for the Air Force Academy for Tuesday, April 30, 2024: If the trigger temperature of 56.4 F/13.5 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 651 ft/min (3.3 m/s) Maximum height of thermals.................. 17707 ft MSL (10111 ft AGL) Forecast maximum temperature................... 71.0 F/22.1 C Time of trigger temperature.................... 0930 MDT Time of overdevelopment........................ None Middle/high clouds during soaring window....... Broken/overcast thin middle Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 15934 ft MSL (8338 ft AGL) Thermal soaring outlook for Wednesday 05/01.... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:01:24 / 19:51:25 MDT Total possible sunshine........... 13 hr 50 min 1 sec (830 min 1 sec) Altitude of sun at 12:56:24 MDT... 66.11 degrees Upper air data from numerical model forecast valid on 04/30/2024 at 0600 MDT Freezing level.................. 12463 ft MSL (4867 ft AGL) Convective condensation level... 19185 ft MSL (11589 ft AGL) Lifted condensation level....... 19093 ft MSL (11498 ft AGL) Lifted index.................... -2.1 K index......................... -17.1 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 -58.2 -72.8 255 43 22 1.2 0.6 M M M M M 45000 -56.6 -69.9 260 65 33 -0.5 -0.3 M M M M M 40000 -57.2 -71.0 255 75 39 -0.4 -0.2 M M M M M 38000 -55.7 -68.3 260 72 37 3.8 2.1 M M M M M 36000 -53.4 -64.1 260 65 33 3.8 2.1 M M M M M 34000 -50.4 -58.7 265 61 31 7.3 4.0 M M M M M 32000 -46.0 -50.8 265 61 31 7.3 4.0 M M M M M 30000 -41.4 -42.5 260 61 32 8.6 4.7 26.7 80.0 3.9 M M 29000 -38.8 -37.8 260 62 32 8.6 4.7 26.2 79.1 3.5 M M 28000 -36.2 -33.2 260 62 32 8.6 4.7 25.8 78.4 3.3 M M 27000 -33.6 -28.5 260 62 32 8.7 4.8 25.5 77.9 3.0 M M 26000 -31.0 -23.8 260 59 30 8.7 4.8 25.0 76.9 2.7 M M 25000 -28.4 -19.1 265 57 29 8.7 4.8 24.6 76.3 2.4 M M 24000 -25.8 -14.4 265 55 28 8.5 4.7 24.3 75.8 2.2 M M 23000 -23.3 -9.9 265 50 26 8.3 4.5 23.7 74.6 1.7 M M 22000 -20.2 -4.4 265 45 23 8.3 4.5 23.0 73.5 1.2 M M 21000 -17.6 0.3 265 40 21 9.6 5.3 22.7 72.9 0.9 M M 20000 -14.7 5.5 255 35 18 9.5 5.2 22.6 72.7 0.8 M M 19500 -13.3 8.1 250 33 17 9.6 5.2 22.6 72.6 0.8 M M 19000 -11.9 10.6 245 31 16 9.8 5.4 22.6 72.6 0.8 M M 18500 -10.6 12.9 245 31 16 6.9 3.8 22.4 72.3 0.6 M M 18000 -9.6 14.7 250 33 17 6.9 3.8 21.9 71.4 0.2 M M 17500 -8.5 16.7 255 35 18 5.8 3.2 21.4 70.6 -0.2 827 4.2 17000 -7.9 17.8 260 37 19 3.9 2.1 20.5 68.9 -1.1 794 4.0 16500 -7.4 18.7 265 39 20 4.0 2.2 19.5 67.2 -2.0 762 3.9 16000 -6.8 19.8 265 34 18 3.5 1.9 18.5 65.4 -2.9 731 3.7 15500 -6.3 20.7 255 25 13 3.5 1.9 17.5 63.6 -3.9 701 3.6 15000 -5.7 21.7 240 18 9 7.0 3.9 16.7 62.0 -4.8 667 3.4 14500 -4.4 24.1 250 18 9 8.2 4.5 16.4 61.6 -5.0 615 3.1 14000 -3.2 26.2 265 20 10 7.8 4.3 16.2 61.2 -5.2 562 2.9 13500 -2.1 28.2 265 22 11 7.2 4.0 15.8 60.5 -5.7 516 2.6 13000 -1.1 30.0 265 24 13 8.6 4.7 15.4 59.7 -6.1 470 2.4 12500 -0.1 31.8 270 27 14 4.4 2.4 15.0 58.9 -6.6 425 2.2 12000 0.6 33.1 270 31 16 5.4 3.0 14.2 57.6 -7.4 390 2.0 11750 1.1 34.0 275 32 17 8.2 4.5 14.0 57.1 -7.7 368 1.9 11500 1.7 35.1 275 33 17 8.4 4.6 13.9 57.0 -7.8 341 1.7 11250 2.3 36.1 275 35 18 7.2 4.0 13.7 56.7 -8.0 318 1.6 11000 2.8 37.0 275 37 19 7.4 4.1 13.5 56.4 -8.3 295 1.5 10750 3.3 37.9 275 39 20 6.2 3.4 13.3 56.0 -8.5 273 1.4 10500 3.7 38.7 280 43 22 5.6 3.1 13.0 55.4 -8.9 253 1.3 10250 4.1 39.4 280 46 24 6.6 3.6 12.7 54.9 -9.2 233 1.2 10000 4.6 40.3 280 48 25 7.1 3.9 12.5 54.5 -9.4 210 1.1 9750 5.1 41.2 280 49 25 7.2 3.9 12.3 54.1 -9.7 187 1.0 9500 5.7 42.3 280 48 25 7.2 3.9 12.1 53.8 -9.9 164 0.8 9250 6.2 43.2 280 47 24 7.5 4.1 11.9 53.4 -10.1 141 0.7 9000 6.7 44.1 275 45 23 5.8 3.2 11.7 53.1 -10.4 119 0.6 8750 7.0 44.6 275 43 22 2.9 1.6 11.3 52.3 -10.9 103 0.5 8500 7.1 44.8 275 39 20 0.9 0.5 10.7 51.2 -11.5 91 0.5 8250 7.2 45.0 275 36 18 5.2 2.9 10.1 50.2 -12.1 80 0.4 8000 7.6 45.7 270 32 16 -0.3 -0.2 9.8 49.6 -12.5 61 0.3 7750 6.7 44.1 270 21 11 -23.0 -12.6 8.1 46.7 -14.2 81 0.4 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 * * * * * * 04/30/2024 at 0900 MDT | 04/30/2024 at 1200 MDT | CAPE... 0.0 LI... +4.1 | CAPE... 0.0 LI... +1.9 CINH... 0.0 K Index... -16.7 | CINH... 0.0 K Index... -13.0 | 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 -56.8 -70.2 255 38 19 0.7 0.4 | -56.5 -69.7 250 42 21 1.5 0.8 45000 -55.9 -68.6 260 64 33 -1.2 -0.7 | -54.6 -66.3 260 63 33 -2.4 -1.3 40000 -57.8 -72.0 255 78 40 -1.3 -0.7 | -58.5 -73.3 260 79 41 -2.4 -1.3 38000 -56.5 -69.7 255 77 40 4.1 2.2 | -57.3 -71.1 260 75 38 3.9 2.1 36000 -54.1 -65.4 260 72 37 4.1 2.2 | -55.0 -67.0 265 66 34 3.9 2.1 34000 -51.1 -60.0 260 68 35 7.2 3.9 | -51.7 -61.1 270 59 31 8.7 4.8 32000 -46.7 -52.1 260 66 34 7.2 3.9 | -46.4 -51.5 265 59 30 8.7 4.8 30000 -42.2 -44.0 260 64 33 8.5 4.7 | -41.3 -42.3 265 59 30 8.1 4.5 29000 -39.6 -39.3 260 63 33 8.6 4.7 | -38.8 -37.8 265 60 31 8.1 4.5 28000 -37.0 -34.6 260 62 32 8.6 4.7 | -36.4 -33.5 265 62 32 8.1 4.5 27000 -34.5 -30.1 260 61 31 8.3 4.6 | -34.0 -29.2 265 63 32 8.2 4.5 26000 -32.0 -25.6 260 59 30 8.3 4.5 | -31.5 -24.7 265 61 31 8.2 4.5 25000 -29.5 -21.1 260 57 29 8.3 4.5 | -29.0 -20.2 265 59 31 8.2 4.5 24000 -27.0 -16.6 260 55 28 8.3 4.6 | -26.6 -15.9 260 58 30 7.8 4.3 23000 -23.9 -11.0 260 51 26 8.4 4.6 | -23.9 -11.0 260 56 29 7.2 4.0 22000 -21.4 -6.5 255 49 25 8.4 4.6 | -21.7 -7.1 265 54 28 7.2 4.0 21000 -18.8 -1.8 250 45 23 9.4 5.1 | -19.5 -3.1 265 52 27 7.8 4.3 20000 -16.0 3.2 245 40 21 9.3 5.1 | -17.1 1.2 265 51 26 7.7 4.2 19500 -14.6 5.7 240 38 20 9.3 5.1 | -16.0 3.2 270 50 26 7.7 4.2 19000 -13.2 8.2 235 36 19 9.4 5.1 | -14.8 5.4 270 49 25 7.7 4.2 18500 -11.8 10.8 235 35 18 8.9 4.9 | -13.6 7.5 270 48 24 8.3 4.5 18000 -10.5 13.1 240 35 18 8.9 4.9 | -12.4 9.7 270 45 23 8.2 4.5 17500 -9.1 15.6 245 35 18 8.4 4.6 | -11.1 12.0 265 42 22 8.0 4.4 17000 -8.0 17.6 245 34 18 7.7 4.2 | -10.0 14.0 270 43 22 7.8 4.3 16500 -6.8 19.8 250 34 17 7.9 4.3 | -8.8 16.2 270 43 22 7.7 4.2 16000 -5.8 21.6 250 33 17 5.5 3.0 | -7.8 18.0 270 42 22 5.8 3.2 15500 -4.9 23.2 255 34 17 5.9 3.2 | -6.9 19.6 270 39 20 6.1 3.4 15000 -4.2 24.4 260 34 18 3.3 1.8 | -6.2 20.8 270 37 19 3.6 2.0 14500 -3.8 25.2 265 34 17 2.7 1.5 | -5.8 21.6 275 36 19 3.6 2.0 14000 -3.5 25.7 270 34 18 3.0 1.7 | -5.2 22.6 280 35 18 6.6 3.6 13500 -3.0 26.6 275 38 19 3.6 2.0 | -4.1 24.6 275 29 15 8.4 4.6 13000 -2.6 27.3 280 42 21 6.6 3.6 | -3.0 26.6 275 23 12 11.6 6.3 12500 -1.7 28.9 285 44 23 3.8 2.1 | -1.3 29.7 275 22 11 7.6 4.2 12000 -1.1 30.0 285 46 24 4.8 2.6 | -0.1 31.8 275 20 10 9.1 5.0 11750 -0.7 30.7 290 46 24 6.6 3.6 | 0.6 33.1 280 19 10 10.5 5.7 11500 -0.2 31.6 290 45 23 6.4 3.5 | 1.4 34.5 280 18 9 10.0 5.5 11250 0.2 32.4 290 42 22 5.6 3.1 | 2.1 35.8 280 18 9 9.7 5.3 11000 0.6 33.1 290 40 21 5.8 3.2 | 2.9 37.2 280 18 9 9.6 5.3 10750 1.0 33.8 290 37 19 5.5 3.0 | 3.6 38.5 280 17 9 9.3 5.1 10500 1.3 34.3 295 33 17 5.4 3.0 | 4.3 39.7 280 17 9 9.4 5.2 10250 1.8 35.2 295 30 15 6.6 3.6 | 5.0 41.0 280 17 9 10.4 5.7 10000 2.3 36.1 295 26 14 7.5 4.1 | 5.8 42.4 280 16 8 10.4 5.7 9750 2.8 37.0 300 23 12 7.5 4.1 | 6.5 43.7 280 16 8 9.7 5.3 9500 3.4 38.1 305 20 10 7.3 4.0 | 7.3 45.1 280 16 8 9.4 5.2 9250 3.9 39.0 310 17 9 8.5 4.7 | 8.0 46.4 280 15 8 10.7 5.8 9000 4.6 40.3 320 14 7 10.4 5.7 | 8.8 47.8 285 15 8 11.3 6.2 8750 5.4 41.7 325 13 7 10.1 5.6 | 9.6 49.3 285 15 8 10.3 5.7 8500 6.2 43.2 330 12 6 10.3 5.7 | 10.4 50.7 285 14 7 10.7 5.9 8250 6.9 44.4 335 11 6 9.1 5.0 | 11.2 52.2 285 14 7 9.8 5.4 8000 7.6 45.7 340 10 5 12.4 6.8 | 12.0 53.6 285 13 7 16.5 9.1 7750 8.9 48.0 345 10 5 21.4 11.7 | 13.8 56.8 285 12 6 29.9 16.4 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 04/30/2024 at 1500 MDT | 04/30/2024 at 1800 MDT | CAPE... +9.7 LI... +0.4 | CAPE... +87.5 LI... -0.7 CINH... -0.2 K Index... +3.5 | CINH... -9.0 K Index... +16.3 | 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 -58.2 -72.8 250 43 22 1.8 1.0 | -58.0 -72.4 255 49 25 1.5 0.8 45000 -55.7 -68.3 265 64 33 -2.4 -1.3 | -56.0 -68.8 265 65 34 -2.7 -1.5 40000 -59.2 -74.6 265 73 38 -2.3 -1.3 | -59.6 -75.3 270 72 37 -2.5 -1.3 38000 -57.6 -71.7 265 72 37 5.1 2.8 | -57.8 -72.0 270 73 37 5.7 3.1 36000 -54.5 -66.1 265 69 35 5.1 2.8 | -54.4 -65.9 270 72 37 5.7 3.1 34000 -50.7 -59.3 265 66 34 8.5 4.7 | -50.5 -58.9 270 71 37 8.2 4.5 32000 -45.6 -50.1 265 66 34 8.5 4.7 | -45.5 -49.9 270 69 35 8.2 4.5 30000 -40.6 -41.1 270 65 33 8.3 4.6 | -40.6 -41.1 270 67 34 8.2 4.5 29000 -38.1 -36.6 265 64 33 8.3 4.6 | -38.2 -36.8 270 66 34 8.2 4.5 28000 -35.6 -32.1 265 63 32 8.3 4.6 | -35.7 -32.3 270 65 34 8.3 4.5 27000 -33.1 -27.6 265 62 32 7.3 4.0 | -33.3 -27.9 270 64 33 6.4 3.5 26000 -31.0 -23.8 265 60 31 7.3 4.0 | -31.5 -24.7 270 62 32 6.3 3.4 25000 -28.8 -19.8 265 58 30 7.3 4.0 | -29.6 -21.3 265 60 31 6.3 3.4 24000 -26.6 -15.9 265 57 29 6.8 3.7 | -27.7 -17.9 265 58 30 6.4 3.5 23000 -24.2 -11.6 265 54 28 6.4 3.5 | -25.7 -14.3 260 53 27 6.6 3.6 22000 -22.3 -8.1 265 52 27 6.4 3.5 | -23.3 -9.9 260 47 24 6.6 3.6 21000 -20.3 -4.5 265 48 25 7.2 4.0 | -21.1 -6.0 255 41 21 8.1 4.5 20000 -18.1 -0.6 265 41 21 7.2 4.0 | -18.7 -1.7 255 35 18 8.2 4.5 19500 -17.1 1.2 260 38 20 7.2 4.0 | -17.5 0.5 255 31 16 8.2 4.5 19000 -16.0 3.2 260 35 18 7.2 3.9 | -16.3 2.7 250 28 14 8.2 4.5 18500 -14.9 5.2 260 32 16 7.3 4.0 | -15.0 5.0 250 25 13 8.7 4.8 18000 -13.8 7.2 265 30 15 7.3 4.0 | -13.8 7.2 250 23 12 8.7 4.8 17500 -12.7 9.1 265 27 14 7.4 4.1 | -12.5 9.5 255 20 10 9.0 5.0 17000 -11.7 10.9 265 24 12 7.6 4.2 | -11.2 11.8 250 18 9 9.2 5.0 16500 -10.6 12.9 260 21 11 7.9 4.3 | -9.8 14.4 250 16 8 9.2 5.1 16000 -9.3 15.3 260 18 9 9.1 5.0 | -8.4 16.9 250 14 7 9.4 5.1 15500 -8.0 17.6 260 15 8 9.1 5.0 | -7.1 19.2 250 12 6 9.4 5.1 15000 -6.6 20.1 260 13 7 9.8 5.4 | -5.7 21.7 245 10 5 9.4 5.1 14500 -5.2 22.6 260 12 6 9.8 5.4 | -4.3 24.3 245 9 5 9.4 5.1 14000 -3.8 25.2 265 11 5 9.7 5.3 | -2.9 26.8 245 7 4 9.6 5.3 13500 -2.3 27.9 265 10 5 9.8 5.4 | -1.4 29.5 240 6 3 9.7 5.3 13000 -0.8 30.6 265 10 5 11.5 6.3 | 0.0 32.0 235 5 3 10.8 5.9 12500 0.7 33.3 265 10 5 8.1 4.5 | 1.5 34.7 230 5 2 8.3 4.5 12000 2.0 35.6 265 9 5 9.3 5.1 | 2.8 37.0 215 4 2 9.0 4.9 11750 2.8 37.0 265 9 5 10.4 5.7 | 3.5 38.3 210 4 2 9.6 5.3 11500 3.5 38.3 265 9 5 10.0 5.5 | 4.2 39.6 205 4 2 9.5 5.2 11250 4.3 39.7 265 9 4 10.1 5.5 | 4.9 40.8 200 4 2 9.7 5.3 11000 5.0 41.0 265 9 4 9.7 5.3 | 5.6 42.1 190 4 2 9.3 5.1 10750 5.7 42.3 265 8 4 9.2 5.0 | 6.3 43.3 185 4 2 8.5 4.7 10500 6.4 43.5 265 8 4 9.5 5.2 | 6.9 44.4 180 4 2 9.1 5.0 10250 7.1 44.8 265 8 4 10.5 5.7 | 7.7 45.9 175 4 2 10.9 6.0 10000 7.9 46.2 270 8 4 10.5 5.8 | 8.5 47.3 170 4 2 10.7 5.8 9750 8.7 47.7 270 8 4 9.9 5.5 | 9.2 48.6 165 4 2 9.5 5.2 9500 9.4 48.9 270 8 4 10.1 5.5 | 9.9 49.8 165 4 2 9.6 5.2 9250 10.2 50.4 270 7 4 9.8 5.4 | 10.6 51.1 160 4 2 9.8 5.4 9000 10.9 51.6 270 7 4 10.2 5.6 | 11.4 52.5 155 4 2 9.9 5.4 8750 11.7 53.1 270 7 4 10.5 5.8 | 12.1 53.8 155 4 2 9.6 5.3 8500 12.5 54.5 270 7 3 10.6 5.8 | 12.8 55.0 155 4 2 9.7 5.3 8250 13.3 55.9 270 7 3 9.9 5.4 | 13.6 56.5 150 4 2 9.6 5.2 8000 14.1 57.4 275 6 3 15.9 8.7 | 14.3 57.7 150 4 2 12.0 6.6 7750 15.8 60.4 275 6 3 28.1 15.4 | 15.3 59.5 145 4 2 16.3 9.0 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 ________________________________________________________________________________ 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