Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
977 UXUS97 KBOU 161314 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0713 MDT Sunday, June 16, 2024 This forecast is for Sunday, June 16, 2024: If the trigger temperature of 85.9 F/30.0 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1578 ft/min (8.0 m/s) Maximum height of thermals.................. 21355 ft MSL (16036 ft AGL) Forecast maximum temperature................... 95.0 F/35.5 C Time of trigger temperature.................... 1200 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................. 16790 ft MSL (11471 ft AGL) Thermal soaring outlook for Monday 06/17....... Excellent Wave Soaring Index............................. Poor Wave Soaring Index trend (to 1800 MDT)......... Little change Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1800 MDT)................ Neither Potential height of wave....................... 40494 ft MSL (35175 ft AGL) Wave soaring outlook for Monday 06/17.......... Poor Remarks... Weak front moves through this morning Sunrise/Sunset.................... 05:30:56 / 20:29:49 MDT Total possible sunshine........... 14 hr 58 min 53 sec (898 min 53 sec) Altitude of sun at 13:00:23 MDT... 73.61 degrees Upper air data from numerical model forecast valid on 06/16/2024 at 0600 MDT Freezing level.................. 15837 ft MSL (10518 ft AGL) Convective condensation level... 18920 ft MSL (13601 ft AGL) Lifted condensation level....... 20008 ft MSL (14689 ft AGL) Lifted index.................... -1.6 K index......................... +14.8 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 -60.9 -77.6 260 38 20 1.1 0.6 M M M M M 45000 -58.7 -73.7 270 48 25 2.2 1.2 M M M M M 40000 -55.0 -67.0 280 63 32 7.9 4.3 M M M M M 38000 -50.6 -59.1 280 58 30 7.4 4.1 M M M M M 36000 -46.1 -51.0 280 53 27 7.4 4.1 M M M M M 34000 -41.5 -42.7 275 48 25 7.8 4.3 M M M M M 32000 -36.3 -33.3 270 43 22 7.7 4.2 M M M M M 30000 -31.8 -25.2 265 38 20 7.4 4.0 43.5 110.2 6.4 M M 29000 -29.6 -21.3 265 36 18 7.4 4.0 42.6 108.6 5.8 M M 28000 -27.4 -17.3 265 34 17 7.4 4.1 41.8 107.2 5.2 M M 27000 -25.2 -13.4 265 32 17 7.4 4.1 40.8 105.4 4.5 M M 26000 -22.9 -9.2 265 31 16 7.4 4.1 39.9 103.8 3.9 M M 25000 -20.7 -5.3 265 30 16 7.5 4.1 39.1 102.5 3.3 M M 24000 -18.6 -1.5 260 29 15 6.7 3.7 38.1 100.5 2.5 M M 23000 -16.6 2.1 260 28 14 6.7 3.7 36.9 98.5 1.5 M M 22000 -14.6 5.7 260 26 14 6.8 3.7 35.9 96.7 0.7 M M 21000 -12.6 9.3 260 26 13 6.9 3.8 34.9 94.7 -0.3 1551 7.9 20000 -10.6 12.9 265 26 13 6.9 3.8 33.8 92.9 -1.2 1462 7.4 19500 -9.6 14.7 265 26 13 7.0 3.8 33.4 92.1 -1.7 1417 7.2 19000 -8.6 16.5 265 26 13 7.9 4.3 32.9 91.3 -2.1 1372 7.0 18500 -7.4 18.7 270 25 13 8.5 4.7 32.7 90.9 -2.3 1319 6.7 18000 -6.1 21.0 270 25 13 8.5 4.7 32.5 90.5 -2.5 1266 6.4 17500 -4.8 23.4 270 24 12 8.9 4.9 32.3 90.2 -2.7 1213 6.2 17000 -2.9 26.8 270 23 12 8.8 4.9 32.1 89.8 -3.0 1132 5.7 16500 -1.5 29.3 270 22 12 9.2 5.0 32.0 89.6 -3.1 1077 5.5 16000 -0.2 31.6 270 21 11 9.1 5.0 31.9 89.4 -3.2 1022 5.2 15500 1.2 34.2 270 20 10 9.2 5.1 31.8 89.2 -3.3 966 4.9 15000 2.6 36.7 270 19 10 9.2 5.1 31.7 89.1 -3.5 910 4.6 14500 3.9 39.0 270 17 9 9.2 5.1 31.6 88.9 -3.6 854 4.3 14000 5.3 41.5 265 16 8 9.2 5.1 31.5 88.8 -3.7 798 4.1 13500 6.7 44.1 265 14 7 9.3 5.1 31.5 88.6 -3.8 742 3.8 13000 8.1 46.6 260 13 7 9.3 5.1 31.4 88.5 -3.9 686 3.5 12500 9.5 49.1 255 12 6 9.3 5.1 31.3 88.4 -4.0 630 3.2 12000 10.8 51.4 250 11 6 9.4 5.1 31.2 88.2 -4.0 573 2.9 11500 12.2 54.0 250 10 5 9.5 5.2 31.2 88.1 -4.1 517 2.6 11000 13.5 56.3 245 10 5 7.6 4.2 31.0 87.8 -4.3 464 2.4 10500 14.6 58.3 240 9 5 9.2 5.0 30.7 87.2 -4.7 415 2.1 10250 15.4 59.7 235 9 5 11.8 6.5 30.8 87.4 -4.6 384 1.9 10000 16.3 61.3 230 9 5 9.7 5.3 30.9 87.5 -4.6 352 1.8 9750 16.9 62.4 230 9 5 8.2 4.5 30.8 87.4 -4.7 325 1.7 9500 17.5 63.5 230 10 5 9.0 4.9 30.7 87.2 -4.8 299 1.5 9250 18.2 64.8 225 10 5 7.2 4.0 30.6 87.0 -4.9 273 1.4 9000 18.6 65.5 225 10 5 7.3 4.0 30.3 86.6 -5.1 251 1.3 8750 19.3 66.7 225 10 5 8.9 4.9 30.2 86.4 -5.3 225 1.1 8500 19.9 67.8 225 11 6 8.8 4.8 30.1 86.3 -5.4 198 1.0 8250 20.5 68.9 225 11 6 7.7 4.2 30.1 86.1 -5.5 172 0.9 8000 21.0 69.8 225 11 6 6.6 3.6 29.8 85.7 -5.7 150 0.8 7750 21.5 70.7 225 12 6 6.9 3.8 29.6 85.3 -6.0 127 0.6 7500 22.0 71.6 220 12 6 7.2 4.0 29.4 84.9 -6.2 105 0.5 7250 22.5 72.5 220 12 6 4.8 2.6 29.2 84.5 -6.5 84 0.4 7000 22.7 72.9 220 12 6 2.1 1.2 28.6 83.5 -7.0 71 0.4 6750 22.8 73.0 225 12 6 2.5 1.4 28.1 82.5 -7.6 59 0.3 6500 22.9 73.2 225 11 6 0.2 0.1 27.5 81.4 -8.3 48 0.2 6250 22.7 72.9 225 11 6 -7.2 -3.9 26.5 79.7 -9.3 49 0.2 6000 21.9 71.4 225 10 5 -10.7 -5.9 25.0 77.0 -10.8 65 0.3 5750 21.0 69.8 225 9 5 -12.0 -6.6 23.5 74.2 -12.4 83 0.4 5500 19.7 67.5 220 7 4 -25.9 -14.2 21.4 70.6 -14.6 117 0.6 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/16/2024 at 0900 MDT | 06/16/2024 at 1200 MDT | CAPE... 0.0 LI... +1.2 | CAPE... +57.3 LI... -0.2 CINH... -0.8 K Index... +10.1 | CINH... -76.1 K Index... +13.1 | 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 -61.7 -79.1 260 40 21 1.2 0.7 | -62.1 -79.8 260 40 21 0.3 0.2 45000 -59.3 -74.7 275 50 26 2.4 1.3 | -60.4 -76.7 270 48 25 3.4 1.8 40000 -55.2 -67.4 280 55 28 8.1 4.5 | -54.9 -66.8 270 52 27 7.7 4.2 38000 -50.6 -59.1 275 52 27 7.8 4.3 | -50.4 -58.7 270 52 27 7.5 4.1 36000 -45.9 -50.6 275 50 26 7.8 4.3 | -45.9 -50.6 270 52 27 7.5 4.1 34000 -41.3 -42.3 270 49 25 7.7 4.2 | -41.2 -42.2 265 53 27 8.0 4.4 32000 -36.6 -33.9 270 48 25 7.8 4.3 | -36.4 -33.5 265 55 28 8.0 4.4 30000 -31.4 -24.5 265 45 23 7.9 4.3 | -31.0 -23.8 265 51 26 8.0 4.4 29000 -29.0 -20.2 260 42 22 7.9 4.3 | -28.6 -19.5 265 49 25 8.0 4.4 28000 -26.7 -16.1 260 40 21 7.6 4.2 | -26.3 -15.3 260 46 24 7.7 4.2 27000 -24.5 -12.1 255 37 19 7.2 4.0 | -24.1 -11.4 255 43 22 7.2 3.9 26000 -22.3 -8.1 255 34 17 7.2 4.0 | -22.0 -7.6 250 39 20 7.2 3.9 25000 -20.2 -4.4 250 30 16 7.3 4.0 | -19.8 -3.6 245 37 19 7.2 4.0 24000 -18.1 -0.6 250 29 15 6.6 3.6 | -17.7 0.1 245 35 18 6.9 3.8 23000 -16.2 2.8 255 28 14 6.6 3.6 | -15.6 3.9 240 33 17 6.9 3.8 22000 -14.2 6.4 255 27 14 6.6 3.6 | -13.6 7.5 240 31 16 7.0 3.9 21000 -12.2 10.0 255 26 14 6.6 3.6 | -11.7 10.9 240 29 15 6.1 3.3 20000 -10.3 13.5 255 25 13 6.7 3.7 | -9.9 14.2 245 28 15 6.2 3.4 19500 -9.3 15.3 255 25 13 6.8 3.7 | -9.0 15.8 245 28 14 6.2 3.4 19000 -8.3 17.1 255 24 13 7.7 4.3 | -8.1 17.4 245 27 14 7.1 3.9 18500 -7.1 19.2 255 24 12 8.3 4.5 | -7.0 19.4 240 27 14 7.7 4.2 18000 -5.9 21.4 255 23 12 8.3 4.6 | -5.9 21.4 240 26 13 7.7 4.2 17500 -4.6 23.7 255 22 11 8.7 4.8 | -4.7 23.5 240 25 13 9.0 5.0 17000 -3.3 26.1 255 21 11 8.7 4.8 | -3.4 25.9 235 24 12 8.9 4.9 16500 -2.0 28.4 255 20 11 8.9 4.9 | -2.0 28.4 235 23 12 9.1 5.0 16000 -0.7 30.7 255 19 10 9.1 5.0 | -0.7 30.7 235 23 12 9.2 5.0 15500 1.4 34.5 250 17 9 9.2 5.1 | 0.7 33.3 235 22 11 9.2 5.1 15000 2.8 37.0 250 16 8 9.3 5.1 | 2.8 37.0 230 21 11 9.5 5.2 14500 4.1 39.4 250 15 8 9.3 5.1 | 4.2 39.6 230 20 10 9.5 5.2 14000 5.5 41.9 245 15 8 9.2 5.1 | 5.6 42.1 225 19 10 9.4 5.2 13500 6.9 44.4 245 14 7 9.2 5.1 | 7.0 44.6 225 19 10 9.4 5.2 13000 8.3 46.9 245 13 7 9.2 5.1 | 8.4 47.1 225 18 9 9.4 5.1 12500 9.6 49.3 245 13 7 9.2 5.1 | 9.8 49.6 220 18 9 9.4 5.2 12000 11.0 51.8 245 13 7 9.0 4.9 | 11.2 52.2 220 17 9 9.4 5.1 11500 12.3 54.1 245 12 6 9.2 5.1 | 12.6 54.7 220 16 8 9.6 5.3 11000 13.5 56.3 245 12 6 7.0 3.8 | 13.9 57.0 220 16 8 7.2 3.9 10500 14.6 58.3 245 12 6 9.3 5.1 | 14.9 58.8 215 15 8 9.3 5.1 10250 15.4 59.7 245 12 6 12.0 6.6 | 15.7 60.3 215 14 7 10.8 5.9 10000 16.2 61.2 245 11 6 9.3 5.1 | 16.4 61.5 215 13 7 7.6 4.1 9750 16.8 62.2 245 11 6 7.8 4.3 | 16.9 62.4 215 12 6 6.4 3.5 9500 17.4 63.3 245 11 6 9.0 4.9 | 17.3 63.1 215 11 6 7.8 4.3 9250 18.0 64.4 245 11 6 5.7 3.1 | 17.8 64.0 215 10 5 3.5 1.9 9000 18.3 64.9 245 10 5 5.5 3.0 | 17.9 64.2 210 9 4 2.5 1.4 8750 18.9 66.0 245 10 5 8.2 4.5 | 18.2 64.8 205 7 3 5.9 3.2 8500 19.5 67.1 240 10 5 8.5 4.6 | 18.6 65.5 200 5 2 5.7 3.1 8250 20.0 68.0 240 10 5 4.9 2.7 | 18.9 66.0 190 3 2 3.3 1.8 8000 20.2 68.4 245 8 4 2.2 1.2 | 19.0 66.2 145 2 1 5.6 3.1 7750 20.4 68.7 245 7 4 4.4 2.4 | 19.7 67.5 125 2 1 10.3 5.6 7500 20.7 69.3 250 7 3 4.1 2.3 | 20.3 68.5 100 2 1 9.4 5.2 7250 20.9 69.6 250 6 3 0.7 0.4 | 21.0 69.8 080 2 1 6.7 3.7 7000 20.8 69.4 265 4 2 -1.4 -0.8 | 21.4 70.5 070 2 1 6.3 3.5 6750 20.7 69.3 285 3 2 0.8 0.4 | 22.1 71.8 060 3 1 12.3 6.8 6500 20.7 69.3 305 3 1 2.5 1.3 | 23.1 73.6 055 3 1 13.1 7.2 6250 20.9 69.6 330 3 1 4.7 2.6 | 23.9 75.0 050 3 2 9.7 5.3 6000 21.2 70.2 345 3 2 5.1 2.8 | 24.6 76.3 045 3 2 9.0 4.9 5750 21.7 71.1 355 3 2 9.6 5.3 | 25.3 77.5 045 4 2 11.1 6.1 5500 22.8 73.0 345 3 2 20.8 11.4 | 26.4 79.5 040 4 2 20.6 11.3 06/16/2024 at 1500 MDT | 06/16/2024 at 1800 MDT | CAPE... +489.7 LI... -2.1 | CAPE... +953.2 LI... -2.5 CINH... -20.4 K Index... +18.6 | CINH... -26.8 K Index... +24.3 | 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 -61.8 -79.2 260 43 22 0.3 0.1 | -60.9 -77.6 255 42 21 1.7 0.9 45000 -60.1 -76.2 265 51 26 3.5 1.9 | -58.0 -72.4 260 50 26 2.3 1.2 40000 -54.4 -65.9 255 51 26 7.4 4.1 | -54.2 -65.6 240 49 25 7.2 3.9 38000 -50.1 -58.2 260 51 26 7.2 3.9 | -50.1 -58.2 240 49 25 6.8 3.7 36000 -45.8 -50.4 260 51 26 7.2 4.0 | -46.1 -51.0 240 50 26 6.8 3.7 34000 -41.1 -42.0 260 52 27 8.1 4.4 | -41.5 -42.7 240 49 25 7.9 4.3 32000 -35.6 -32.1 255 52 27 8.0 4.4 | -36.2 -33.2 245 47 24 7.8 4.3 30000 -31.0 -23.8 255 50 26 7.7 4.2 | -31.7 -25.1 245 44 23 7.4 4.1 29000 -28.7 -19.7 255 49 25 7.7 4.2 | -29.5 -21.1 245 43 22 7.5 4.1 28000 -26.4 -15.5 255 47 24 7.3 4.0 | -27.3 -17.1 245 42 22 7.3 4.0 27000 -24.4 -11.9 250 45 23 6.5 3.6 | -25.2 -13.4 245 40 21 7.0 3.9 26000 -22.5 -8.5 250 42 22 6.5 3.6 | -23.1 -9.6 240 38 20 7.1 3.9 25000 -20.6 -5.1 245 40 20 6.5 3.6 | -21.0 -5.8 240 36 19 7.1 3.9 24000 -18.6 -1.5 245 37 19 6.8 3.7 | -18.9 -2.0 235 34 18 7.3 4.0 23000 -16.6 2.1 240 34 18 6.8 3.7 | -16.7 1.9 235 32 16 7.4 4.0 22000 -14.6 5.7 235 32 16 6.7 3.7 | -14.6 5.7 230 30 15 7.3 4.0 21000 -12.4 9.7 235 30 15 8.0 4.4 | -12.1 10.2 230 28 15 8.7 4.8 20000 -10.0 14.0 230 28 15 8.0 4.4 | -9.6 14.7 225 27 14 8.7 4.8 19500 -8.8 16.2 230 28 14 8.0 4.4 | -8.3 17.1 225 27 14 8.7 4.8 19000 -7.7 18.1 230 27 14 8.7 4.8 | -7.0 19.4 225 26 13 9.2 5.0 18500 -6.3 20.7 230 27 14 9.1 5.0 | -5.6 21.9 225 25 13 9.4 5.2 18000 -5.0 23.0 225 26 14 9.1 5.0 | -4.2 24.4 225 24 12 9.5 5.2 17500 -3.6 25.5 225 26 13 9.3 5.1 | -2.8 27.0 225 23 12 9.4 5.2 17000 -2.2 28.0 225 26 13 9.3 5.1 | -1.4 29.5 225 23 12 9.4 5.2 16500 -0.1 31.8 225 25 13 9.6 5.3 | 0.7 33.3 225 22 11 9.6 5.2 16000 1.3 34.3 220 24 13 9.6 5.3 | 2.1 35.8 225 21 11 9.6 5.2 15500 2.7 36.9 220 24 12 9.5 5.2 | 3.6 38.5 225 20 10 9.4 5.2 15000 4.1 39.4 220 23 12 9.5 5.2 | 4.9 40.8 220 19 10 9.4 5.1 14500 5.5 41.9 220 23 12 9.5 5.2 | 6.3 43.3 220 18 9 9.3 5.1 14000 7.0 44.6 220 22 11 9.5 5.2 | 7.7 45.9 220 16 8 9.3 5.1 13500 8.4 47.1 220 21 11 9.5 5.2 | 9.1 48.4 220 15 8 9.3 5.1 13000 9.8 49.6 215 21 11 9.5 5.2 | 10.5 50.9 220 14 7 9.1 5.0 12500 11.2 52.2 215 20 10 9.6 5.2 | 11.8 53.2 215 13 7 9.2 5.0 12000 12.6 54.7 215 19 10 9.2 5.1 | 13.1 55.6 215 11 6 8.6 4.7 11500 14.0 57.2 210 18 9 9.4 5.2 | 14.3 57.7 210 10 5 8.8 4.8 11000 15.2 59.4 210 16 8 7.4 4.0 | 15.4 59.7 205 8 4 7.2 4.0 10500 16.3 61.3 205 15 8 9.1 5.0 | 16.4 61.5 200 5 3 8.5 4.7 10250 17.0 62.6 205 14 7 10.8 5.9 | 17.1 62.8 200 4 2 10.8 5.9 10000 17.7 63.9 205 12 6 7.7 4.2 | 17.8 64.0 195 3 2 9.2 5.1 9750 18.2 64.8 200 10 5 6.9 3.8 | 18.4 65.1 180 2 1 8.5 4.7 9500 18.6 65.5 195 9 4 6.6 3.6 | 19.0 66.2 145 1 1 8.3 4.6 9250 19.1 66.4 190 7 4 8.9 4.9 | 19.7 67.5 080 1 1 10.0 5.5 9000 19.8 67.6 190 6 3 10.5 5.8 | 20.5 68.9 075 1 1 10.6 5.8 8750 20.5 68.9 185 5 3 9.1 5.0 | 21.2 70.2 065 2 1 9.2 5.1 8500 21.2 70.2 175 4 2 9.9 5.5 | 21.9 71.4 060 2 1 9.9 5.4 8250 21.9 71.4 165 4 2 8.1 4.4 | 22.6 72.7 060 2 1 8.5 4.7 8000 22.4 72.3 145 3 2 8.8 4.8 | 23.2 73.8 055 4 2 8.9 4.9 7750 23.2 73.8 145 3 2 10.8 6.0 | 23.9 75.0 050 4 2 10.4 5.7 7500 24.0 75.2 140 3 2 10.9 6.0 | 24.7 76.5 050 4 2 10.5 5.7 7250 24.8 76.6 140 3 1 8.7 4.8 | 25.4 77.7 050 4 2 8.6 4.7 7000 25.3 77.5 125 3 1 7.8 4.3 | 26.0 78.8 050 5 2 7.6 4.2 6750 26.0 78.8 120 3 1 11.1 6.1 | 26.7 80.1 050 5 3 10.4 5.7 6500 26.9 80.4 115 3 1 11.8 6.5 | 27.5 81.5 050 5 3 11.4 6.2 6250 27.8 82.0 115 3 1 10.7 5.9 | 28.3 82.9 050 5 3 10.3 5.7 6000 28.5 83.3 100 3 1 10.4 5.7 | 29.0 84.2 045 6 3 9.7 5.3 5750 29.3 84.7 090 3 2 10.0 5.5 | 29.8 85.6 045 6 3 9.7 5.3 5500 30.2 86.4 090 3 1 16.4 9.0 | 30.5 86.9 045 5 3 12.6 6.9 ________________________________________________________________________________ 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