Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
026 UXUS97 KBOU 061220 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0619 MDT Saturday, July 6, 2024 This forecast is for Saturday, July 6, 2024: If the trigger temperature of 79.9 F/26.6 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1517 ft/min (7.7 m/s) Maximum height of thermals.................. 21097 ft MSL (15770 ft AGL) Forecast maximum temperature................... 91.0 F/33.2 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................. 17902 ft MSL (12575 ft AGL) Thermal soaring outlook for Sunday 07/07....... Excellent Wave Soaring Index............................. Poor Wave Soaring Index trend (to 1800 MDT)......... No change Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1800 MDT)................ Weak PVA Potential height of wave....................... 18583 ft MSL (13256 ft AGL) Wave soaring outlook for Sunday 07/07.......... Good Remarks... None Sunrise/Sunset.................... 05:38:25 / 20:30:24 MDT Total possible sunshine........... 14 hr 51 min 59 sec (891 min 59 sec) Altitude of sun at 13:04:24 MDT... 72.78 degrees Upper air data from numerical model forecast valid on 07/06/2024 at 0600 MDT Freezing level.................. 14598 ft MSL (9271 ft AGL) Convective condensation level... 18934 ft MSL (13607 ft AGL) Lifted condensation level....... 20031 ft MSL (14704 ft AGL) Lifted index.................... -1.2 K index......................... +15.8 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 -57.5 -71.5 305 37 19 1.6 0.9 M M M M M 45000 -54.8 -66.6 300 55 28 2.3 1.2 M M M M M 40000 -51.1 -60.0 295 51 26 4.0 2.2 M M M M M 38000 -48.8 -55.8 300 48 25 3.9 2.1 M M M M M 36000 -46.5 -51.7 300 45 23 3.9 2.2 M M M M M 34000 -43.0 -45.4 300 42 22 6.8 3.7 M M M M M 32000 -38.9 -38.0 295 40 21 6.8 3.7 M M M M M 30000 -34.7 -30.5 300 37 19 7.1 3.9 41.2 106.2 6.4 M M 29000 -32.1 -25.8 300 36 18 7.1 3.9 40.0 104.0 5.5 M M 28000 -29.9 -21.8 300 35 18 7.3 4.0 39.1 102.4 4.9 M M 27000 -27.6 -17.7 305 34 17 7.8 4.3 38.2 100.8 4.3 M M 26000 -25.3 -13.5 305 33 17 7.8 4.3 37.5 99.5 3.7 M M 25000 -23.0 -9.4 310 32 16 7.9 4.3 36.9 98.3 3.3 M M 24000 -20.8 -5.4 310 31 16 7.0 3.8 35.9 96.6 2.5 M M 23000 -18.7 -1.7 310 30 16 7.0 3.8 34.9 94.8 1.7 M M 22000 -16.6 2.1 310 29 15 7.0 3.9 34.0 93.1 0.9 M M 21000 -14.7 5.5 310 29 15 6.6 3.6 32.8 91.1 -0.1 1512 7.7 20000 -12.7 9.1 310 29 15 6.6 3.6 31.7 89.1 -1.1 1425 7.2 19500 -11.8 10.8 305 29 15 6.7 3.7 31.2 88.1 -1.5 1381 7.0 19000 -10.8 12.6 305 29 15 7.1 3.9 30.7 87.3 -2.0 1337 6.8 18500 -9.7 14.5 305 29 15 7.2 3.9 30.3 86.5 -2.4 1291 6.6 18000 -8.7 16.3 300 30 15 7.3 4.0 29.8 85.7 -2.8 1244 6.3 17500 -7.6 18.3 300 30 15 7.6 4.2 29.4 85.0 -3.3 1198 6.1 17000 -6.5 20.3 295 30 15 7.6 4.2 29.1 84.3 -3.6 1150 5.8 16500 -5.4 22.3 295 30 15 8.6 4.7 28.8 83.8 -4.0 1101 5.6 16000 -3.5 25.7 295 28 14 8.8 4.8 28.5 83.3 -4.3 1022 5.2 15500 -2.2 28.0 295 27 14 9.0 4.9 28.4 83.1 -4.5 968 4.9 15000 -0.8 30.6 295 25 13 9.0 4.9 28.2 82.8 -4.6 913 4.6 14500 0.5 32.9 295 24 12 8.8 4.8 28.1 82.6 -4.7 858 4.4 14000 1.8 35.2 300 23 12 8.8 4.8 27.9 82.3 -4.9 804 4.1 13500 3.1 37.6 300 21 11 9.0 5.0 27.8 82.0 -5.1 751 3.8 13000 4.5 40.1 300 20 10 9.3 5.1 27.7 81.9 -5.2 694 3.5 12500 5.9 42.6 305 19 10 9.4 5.2 27.6 81.8 -5.3 638 3.2 12000 7.3 45.1 305 19 10 9.5 5.2 27.6 81.7 -5.4 580 2.9 11500 8.7 47.7 305 18 9 9.5 5.2 27.6 81.6 -5.4 523 2.7 11000 10.1 50.2 305 18 9 9.0 4.9 27.5 81.5 -5.5 466 2.4 10500 11.5 52.7 305 18 9 4.3 2.4 27.5 81.4 -5.6 410 2.1 10250 11.7 53.1 305 18 9 5.6 3.1 26.8 80.3 -6.2 398 2.0 10000 12.5 54.5 305 18 9 12.8 7.0 27.0 80.5 -6.1 365 1.9 9750 13.4 56.1 300 18 9 11.2 6.1 27.1 80.8 -6.0 332 1.7 9500 14.2 57.6 300 18 9 10.6 5.8 27.2 81.0 -5.9 300 1.5 9250 14.9 58.8 300 18 9 8.3 4.6 27.2 80.9 -5.9 271 1.4 9000 15.5 59.9 300 18 9 9.0 4.9 27.1 80.7 -6.0 245 1.2 8750 16.3 61.3 300 19 10 10.1 5.5 27.1 80.7 -6.1 216 1.1 8500 17.0 62.6 300 19 10 9.5 5.2 27.1 80.8 -6.1 187 0.9 8250 17.7 63.9 300 19 10 9.2 5.1 27.0 80.7 -6.1 158 0.8 8000 18.4 65.1 300 19 10 8.6 4.7 27.0 80.6 -6.2 131 0.7 7750 19.0 66.2 295 19 10 8.1 4.4 26.9 80.4 -6.3 106 0.5 7500 19.5 67.1 290 19 10 7.4 4.1 26.7 80.1 -6.5 81 0.4 7250 20.0 68.0 290 20 10 6.7 3.7 26.5 79.7 -6.7 59 0.3 7000 20.5 68.9 285 20 10 7.0 3.8 26.3 79.3 -7.0 36 0.2 6750 21.0 69.8 285 20 10 5.8 3.2 26.1 78.9 -7.3 15 0.1 6500 21.2 70.2 275 19 10 -0.1 -0.0 25.6 78.0 -7.8 1 0.0 6250 20.9 69.6 270 18 9 -4.2 -2.3 24.6 76.3 -8.8 2 0.0 6000 20.7 69.3 265 18 9 -0.9 -0.5 23.6 74.6 -9.8 3 0.0 5750 20.4 68.7 255 17 9 -10.8 -5.9 22.7 72.8 -10.9 4 0.0 5500 18.5 65.3 245 12 6 -34.8 -19.1 20.2 68.4 -13.5 52 0.3 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 07/06/2024 at 0900 MDT | 07/06/2024 at 1200 MDT | CAPE... 0.0 LI... +2.2 | CAPE... 0.0 LI... +1.6 CINH... -0.2 K Index... +14.6 | CINH... 0.0 K Index... +15.5 | 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 -57.2 -71.0 300 32 16 2.1 1.2 | -57.7 -71.9 290 37 19 3.0 1.7 45000 -54.0 -65.2 300 54 28 2.0 1.1 | -53.6 -64.5 300 58 30 1.7 0.9 40000 -50.8 -59.4 300 57 30 3.0 1.7 | -50.9 -59.6 300 64 33 2.8 1.5 38000 -49.0 -56.2 300 53 27 2.9 1.6 | -49.3 -56.7 300 59 30 2.7 1.5 36000 -47.3 -53.1 300 49 25 3.0 1.6 | -47.7 -53.9 300 54 28 2.7 1.5 34000 -44.0 -47.2 300 46 24 6.6 3.6 | -44.4 -47.9 300 51 26 6.9 3.8 32000 -40.0 -40.0 310 44 23 6.6 3.6 | -40.3 -40.5 295 48 25 6.9 3.8 30000 -34.8 -30.6 310 41 21 8.4 4.6 | -35.4 -31.7 295 47 24 8.8 4.8 29000 -32.3 -26.1 310 40 21 8.4 4.6 | -32.1 -25.8 295 46 24 8.8 4.8 28000 -29.7 -21.5 310 39 20 8.2 4.5 | -29.5 -21.1 295 45 23 8.3 4.6 27000 -27.4 -17.3 310 36 19 7.6 4.2 | -27.3 -17.1 295 44 23 7.5 4.1 26000 -25.2 -13.4 310 34 18 7.6 4.2 | -25.0 -13.0 290 42 22 7.5 4.1 25000 -22.9 -9.2 305 32 16 7.7 4.2 | -22.8 -9.0 290 40 21 7.5 4.1 24000 -20.7 -5.3 305 30 16 7.3 4.0 | -20.6 -5.1 285 38 19 7.4 4.1 23000 -18.5 -1.3 305 29 15 7.3 4.0 | -18.4 -1.1 285 34 18 7.4 4.1 22000 -16.3 2.7 300 27 14 7.4 4.0 | -16.2 2.8 285 31 16 7.5 4.1 21000 -14.4 6.1 300 27 14 6.2 3.4 | -14.2 6.4 285 30 15 6.2 3.4 20000 -12.6 9.3 300 27 14 6.2 3.4 | -12.4 9.7 285 29 15 6.3 3.4 19500 -11.6 11.1 295 27 14 6.3 3.4 | -11.4 11.5 285 29 15 6.3 3.4 19000 -10.7 12.7 295 27 14 6.4 3.5 | -10.5 13.1 285 28 15 6.2 3.4 18500 -9.8 14.4 295 27 14 6.5 3.6 | -9.6 14.7 285 28 14 6.2 3.4 18000 -8.8 16.2 290 28 14 6.7 3.7 | -8.7 16.3 285 28 14 6.3 3.5 17500 -7.8 18.0 290 28 14 7.8 4.3 | -7.7 18.1 285 28 14 7.3 4.0 17000 -6.7 19.9 285 28 14 7.7 4.2 | -6.7 19.9 285 27 14 7.2 4.0 16500 -5.5 22.1 285 28 14 8.3 4.6 | -5.6 21.9 285 26 14 8.7 4.8 16000 -3.7 25.3 285 26 13 8.5 4.6 | -4.3 24.3 285 25 13 9.0 4.9 15500 -2.5 27.5 280 25 13 8.4 4.6 | -3.0 26.6 285 24 12 8.9 4.9 15000 -1.2 29.8 285 23 12 8.4 4.6 | -1.1 30.0 280 22 11 8.7 4.8 14500 0.0 32.0 285 22 11 8.7 4.8 | 0.2 32.4 280 21 11 8.9 4.9 14000 1.4 34.5 285 21 11 8.8 4.8 | 1.6 34.9 280 20 10 9.0 4.9 13500 2.7 36.9 285 19 10 8.8 4.8 | 2.9 37.2 285 18 9 8.9 4.9 13000 4.0 39.2 290 18 9 8.8 4.8 | 4.2 39.6 285 17 9 8.8 4.9 12500 5.3 41.5 295 16 8 8.8 4.8 | 5.5 41.9 285 15 8 8.9 4.9 12000 6.6 43.9 295 15 7 9.0 4.9 | 6.8 44.2 285 14 7 8.9 4.9 11500 8.0 46.4 300 13 7 8.9 4.9 | 8.2 46.8 290 12 6 8.9 4.9 11000 9.3 48.7 305 13 6 8.6 4.7 | 9.5 49.1 295 10 5 8.7 4.8 10500 10.6 51.1 310 13 7 3.7 2.0 | 10.9 51.6 300 8 4 3.2 1.7 10250 10.7 51.3 310 12 6 5.1 2.8 | 10.9 51.6 305 8 4 5.3 2.9 10000 11.5 52.7 315 12 6 12.7 6.9 | 11.8 53.2 305 8 4 14.3 7.8 9750 12.4 54.3 315 12 6 11.1 6.1 | 12.7 54.9 305 8 4 12.3 6.8 9500 13.2 55.8 315 13 6 9.8 5.4 | 13.7 56.7 310 7 4 11.2 6.1 9250 13.8 56.8 320 13 7 6.6 3.6 | 14.4 57.9 310 7 4 8.2 4.5 9000 14.3 57.7 325 13 7 8.6 4.7 | 15.0 59.0 310 7 4 10.0 5.5 8750 15.1 59.2 325 13 7 10.9 6.0 | 15.8 60.4 315 7 4 11.7 6.4 8500 15.8 60.4 325 14 7 9.2 5.1 | 16.7 62.1 315 7 3 10.5 5.7 8250 16.4 61.5 325 14 7 7.6 4.1 | 17.4 63.3 315 7 3 9.0 4.9 8000 17.0 62.6 325 14 7 8.2 4.5 | 18.1 64.6 315 7 4 9.7 5.3 7750 17.7 63.9 325 14 7 9.6 5.3 | 18.9 66.0 320 7 3 11.3 6.2 7500 18.4 65.1 320 14 7 8.5 4.7 | 19.7 67.5 325 6 3 9.6 5.3 7250 18.9 66.0 320 14 7 7.1 3.9 | 20.3 68.5 325 6 3 7.7 4.2 7000 19.5 67.1 320 14 7 8.4 4.6 | 20.9 69.6 325 6 3 9.2 5.1 6750 20.2 68.4 315 14 7 10.8 5.9 | 21.7 71.1 325 6 3 12.4 6.8 6500 21.0 69.8 315 13 7 9.0 4.9 | 22.7 72.9 330 6 3 11.9 6.5 6250 21.5 70.7 315 12 6 7.4 4.1 | 23.5 74.3 330 6 3 10.8 5.9 6000 22.0 71.6 315 10 5 6.1 3.3 | 24.3 75.7 330 6 3 9.5 5.2 5750 22.5 72.5 315 8 4 9.8 5.4 | 25.1 77.2 330 6 3 15.0 8.2 5500 23.7 74.7 315 7 4 23.4 12.8 | 26.8 80.2 335 5 3 31.1 17.1 07/06/2024 at 1500 MDT | 07/06/2024 at 1800 MDT | CAPE... +12.8 LI... 0.0 | CAPE... +65.9 LI... -0.1 CINH... -12.4 K Index... +17.6 | CINH... -12.3 K Index... +17.8 | 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 -57.4 -71.3 285 41 21 3.2 1.7 | -57.1 -70.8 290 40 20 3.3 1.8 45000 -53.3 -63.9 295 57 29 1.3 0.7 | -53.1 -63.6 295 54 28 0.8 0.4 40000 -51.2 -60.2 305 69 36 3.3 1.8 | -51.6 -60.9 300 72 37 3.8 2.1 38000 -49.3 -56.7 305 64 33 3.1 1.7 | -49.5 -57.1 300 69 35 3.4 1.9 36000 -47.5 -53.5 300 58 30 3.2 1.7 | -47.5 -53.5 305 65 34 3.5 1.9 34000 -44.2 -47.6 300 55 28 6.4 3.5 | -44.1 -47.4 305 62 32 6.6 3.6 32000 -40.4 -40.7 300 52 27 6.4 3.5 | -40.1 -40.2 305 58 30 6.6 3.6 30000 -35.7 -32.3 295 49 25 8.7 4.8 | -35.7 -32.3 300 52 27 7.8 4.3 29000 -32.5 -26.5 295 48 25 8.7 4.8 | -32.8 -27.0 300 49 25 7.8 4.3 28000 -29.9 -21.8 295 47 24 8.3 4.6 | -30.5 -22.9 295 46 24 7.8 4.3 27000 -27.6 -17.7 295 46 24 7.7 4.2 | -28.2 -18.8 295 44 23 7.8 4.3 26000 -25.3 -13.5 295 45 23 7.7 4.2 | -25.8 -14.4 295 42 22 7.8 4.3 25000 -23.0 -9.4 295 44 23 7.8 4.3 | -23.5 -10.3 295 40 21 7.9 4.4 24000 -21.0 -5.8 295 41 21 6.4 3.5 | -21.4 -6.5 295 37 19 6.8 3.7 23000 -19.0 -2.2 290 38 20 6.5 3.5 | -19.4 -2.9 295 34 17 6.8 3.8 22000 -17.1 1.2 285 35 18 6.4 3.5 | -17.3 0.9 290 30 16 6.9 3.8 21000 -15.0 5.0 280 32 17 7.3 4.0 | -15.0 5.0 285 28 14 8.2 4.5 20000 -12.9 8.8 275 30 16 7.5 4.1 | -12.6 9.3 280 26 14 8.3 4.5 19500 -11.8 10.8 270 29 15 7.5 4.1 | -11.4 11.5 280 26 13 8.3 4.6 19000 -10.7 12.7 270 29 15 8.7 4.8 | -10.2 13.6 275 25 13 8.9 4.9 18500 -9.4 15.1 270 27 14 9.0 4.9 | -8.9 16.0 275 24 13 9.0 5.0 18000 -8.1 17.4 270 26 13 9.0 4.9 | -7.6 18.3 275 24 12 9.1 5.0 17500 -6.8 19.8 270 25 13 8.9 4.9 | -6.2 20.8 275 23 12 9.3 5.1 17000 -5.5 22.1 270 24 12 8.9 4.9 | -4.8 23.4 280 22 11 9.3 5.1 16500 -4.2 24.4 270 23 12 9.1 5.0 | -3.5 25.7 280 22 11 9.2 5.1 16000 -2.8 27.0 270 22 11 9.1 5.0 | -2.1 28.2 280 21 11 9.2 5.1 15500 -0.7 30.7 270 21 11 9.3 5.1 | -0.0 32.0 280 20 10 9.5 5.2 15000 0.6 33.1 275 20 10 9.3 5.1 | 1.4 34.5 285 19 10 9.5 5.2 14500 2.0 35.6 275 19 10 9.3 5.1 | 2.8 37.0 285 19 10 9.4 5.1 14000 3.4 38.1 275 17 9 9.3 5.1 | 4.2 39.6 285 18 9 9.3 5.1 13500 4.8 40.6 275 16 8 9.1 5.0 | 5.6 42.1 285 17 9 9.3 5.1 13000 6.1 43.0 275 14 7 8.8 4.8 | 7.0 44.6 290 16 8 9.3 5.1 12500 7.4 45.3 280 13 7 8.9 4.9 | 8.3 46.9 290 15 8 9.3 5.1 12000 8.8 47.8 280 12 6 9.4 5.2 | 9.8 49.6 290 15 8 9.5 5.2 11500 10.2 50.4 280 11 5 9.4 5.1 | 11.2 52.2 295 14 7 9.2 5.1 11000 11.6 52.9 285 10 5 8.9 4.9 | 12.3 54.1 295 14 7 7.5 4.1 10500 12.9 55.2 285 9 5 4.3 2.4 | 13.4 56.1 300 14 7 12.7 7.0 10250 13.1 55.6 290 10 5 5.9 3.2 | 14.6 58.3 300 13 7 14.1 7.7 10000 13.9 57.0 290 10 5 13.2 7.2 | 15.3 59.5 300 13 6 8.0 4.4 9750 14.8 58.6 290 9 5 11.5 6.3 | 16.0 60.8 300 12 6 9.9 5.4 9500 15.7 60.3 290 9 5 10.9 6.0 | 16.7 62.1 300 12 6 8.6 4.7 9250 16.4 61.5 295 9 5 8.8 4.8 | 17.3 63.1 305 12 6 8.0 4.4 9000 17.1 62.8 295 10 5 10.0 5.5 | 18.0 64.4 305 12 6 9.9 5.4 8750 17.9 64.2 295 9 5 11.3 6.2 | 18.8 65.8 305 12 6 11.0 6.0 8500 18.7 65.7 295 8 4 10.5 5.8 | 19.6 67.3 305 12 6 10.3 5.7 8250 19.5 67.1 295 9 4 9.1 5.0 | 20.3 68.5 305 12 6 8.7 4.8 8000 20.1 68.2 295 10 5 9.6 5.2 | 20.9 69.6 305 12 6 9.4 5.1 7750 20.9 69.6 295 9 5 10.9 6.0 | 21.7 71.1 305 12 6 11.0 6.0 7500 21.7 71.1 295 8 4 9.7 5.3 | 22.5 72.5 305 11 6 9.8 5.3 7250 22.3 72.1 300 8 4 8.1 4.5 | 23.2 73.8 305 12 6 8.1 4.4 7000 23.0 73.4 300 9 5 9.2 5.0 | 23.8 74.8 305 12 6 8.9 4.9 6750 23.8 74.8 300 9 4 12.6 6.9 | 24.5 76.1 310 12 6 12.4 6.8 6500 24.7 76.5 300 8 4 12.1 6.6 | 25.5 77.9 305 11 6 11.6 6.4 6250 25.5 77.9 300 8 4 10.6 5.8 | 26.3 79.3 310 11 6 9.7 5.3 6000 26.3 79.3 300 8 4 9.9 5.4 | 27.0 80.6 310 11 6 9.8 5.4 5750 27.1 80.8 300 8 4 13.5 7.4 | 27.8 82.0 310 11 6 11.4 6.2 5500 28.6 83.5 300 7 4 27.5 15.1 | 28.8 83.8 305 10 5 18.4 10.1 ________________________________________________________________________________ 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 old Stapleton Airport site in Denver, Colorado at North Latitude: 39 deg 46 min 5.016 sec West Longitude: 104 deg 52 min 9.984 sec Elevation: 5285 feet (1611 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