319 UXUS97 KBOU 041221 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0521 MST Tuesday, March 4, 2025 This forecast is for Tuesday, March 4, 2025: If the trigger temperature of 41.9 F/5.5 C is reached...then Thermal Soaring Index....................... Fair Maximum rate of lift........................ 534 ft/min (2.7 m/s) Maximum height of thermals.................. 12162 ft MSL (6804 ft AGL) Forecast maximum temperature................... 47.0 F/8.8 C Time of trigger temperature.................... 0945 MST Time of overdevelopment........................ 1500 MST Middle/high clouds during soaring window....... None Surface winds during soaring window............ Between 20 mph and 30 mph Height of the -3 thermal index................. 9008 ft MSL (3650 ft AGL) Thermal soaring outlook for Wednesday 03/05.... Good Wave Soaring Index............................. Poor Wave Soaring Index trend (to 1700 MST)......... Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1700 MST)................ Weak NVA Potential height of wave....................... 14447 ft MSL (9089 ft AGL) Wave soaring outlook for Wednesday 03/05....... Poor Remarks... Sunrise/Sunset.................... 06:27:09 / 17:54:57 MST Total possible sunshine........... 11 hr 27 min 48 sec (687 min 48 sec) Altitude of sun at 12:11:03 MST... 44.04 degrees Upper air data from numerical model forecast valid on 03/04/2025 at 0500 MST Freezing level.................. 6526 ft MSL (1168 ft AGL) Convective condensation level... 9635 ft MSL (4277 ft AGL) Lifted condensation level....... 10701 ft MSL (5343 ft AGL) Lifted index.................... +2.4 K index......................... +12.6 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 -51.1 -60.0 245 18 9 4.3 2.4 M M M M M 45000 -44.4 -47.9 225 23 12 3.8 2.1 M M M M M 40000 -41.4 -42.5 245 14 7 1.9 1.1 M M M M M 38000 -40.8 -41.4 265 12 6 -3.2 -1.7 M M M M M 36000 -42.6 -44.7 280 15 8 -3.0 -1.6 M M M M M 34000 -44.4 -47.9 290 19 10 -3.0 -1.6 M M M M M 32000 -47.7 -53.9 315 16 8 -5.7 -3.1 M M M M M 30000 -51.1 -60.0 360 16 8 -6.3 -3.4 M M M M M 29000 -50.3 -58.5 005 18 9 7.8 4.3 21.9 71.4 10.2 M M 28000 -47.9 -54.2 010 20 10 8.0 4.4 21.1 70.0 9.8 M M 27000 -45.5 -49.9 010 22 11 8.0 4.4 20.5 68.8 9.4 M M 26000 -43.0 -45.4 010 24 12 9.4 5.2 20.0 68.0 9.1 M M 25000 -40.3 -40.5 010 27 14 9.3 5.1 19.7 67.5 9.0 M M 24000 -37.5 -35.5 005 29 15 9.3 5.1 19.6 67.2 9.0 M M 23000 -34.8 -30.6 005 31 16 8.4 4.6 19.4 67.0 9.0 M M 22000 -32.3 -26.1 010 32 17 8.4 4.6 18.8 65.9 8.6 M M 21000 -29.8 -21.6 015 34 17 8.3 4.6 18.4 65.1 8.3 M M 20000 -27.6 -17.7 010 35 18 5.5 3.0 17.5 63.5 7.7 M M 19500 -26.8 -16.2 005 36 18 5.6 3.1 16.7 62.1 7.1 M M 19000 -26.0 -14.8 005 37 19 5.6 3.1 16.0 60.8 6.5 M M 18500 -24.7 -12.5 355 39 20 5.6 3.1 15.0 59.0 5.6 M M 18000 -23.9 -11.0 355 40 20 5.9 3.2 14.3 57.8 5.1 M M 17500 -23.0 -9.4 350 39 20 5.9 3.3 13.6 56.5 4.5 M M 17000 -22.1 -7.8 350 39 20 6.2 3.4 13.0 55.4 4.0 M M 16500 -21.1 -6.0 350 39 20 6.8 3.7 12.5 54.4 3.5 M M 16000 -20.1 -4.2 345 39 20 6.7 3.7 12.0 53.5 3.1 M M 15500 -19.0 -2.2 345 40 21 8.0 4.4 11.6 52.8 2.7 M M 15000 -17.8 -0.0 345 41 21 8.1 4.4 11.2 52.2 2.5 M M 14500 -16.8 1.8 345 42 22 6.0 3.3 10.8 51.5 2.1 M M 14000 -15.9 3.4 345 43 22 5.8 3.2 10.2 50.3 1.5 M M 13500 -15.0 5.0 345 44 23 7.2 3.9 9.6 49.2 0.9 M M 13000 -13.9 7.0 340 45 23 7.7 4.2 9.2 48.6 0.6 M M 12500 -12.8 9.0 340 46 23 7.5 4.1 8.9 48.0 0.2 M M 12000 -11.7 10.9 340 46 24 7.4 4.1 8.5 47.3 -0.1 518 2.6 11500 -10.6 12.9 340 47 24 7.1 3.9 8.1 46.7 -0.5 470 2.4 11000 -9.6 14.7 345 48 25 6.9 3.8 7.7 45.8 -1.0 426 2.2 10500 -8.6 16.5 345 49 25 6.0 3.3 7.2 45.0 -1.4 382 1.9 10250 -8.2 17.2 345 49 25 5.5 3.0 6.9 44.4 -1.8 362 1.8 10000 -7.8 18.0 350 49 25 6.0 3.3 6.6 43.8 -2.1 342 1.7 9750 -7.3 18.9 350 49 25 6.9 3.8 6.3 43.3 -2.4 321 1.6 9500 -6.8 19.8 350 49 25 7.3 4.0 6.1 43.0 -2.6 298 1.5 9250 -6.3 20.7 350 48 25 8.2 4.5 5.9 42.7 -2.8 274 1.4 9000 -5.7 21.7 355 48 25 5.6 3.1 5.8 42.4 -2.9 250 1.3 8750 -5.4 22.3 355 48 25 5.3 2.9 5.3 41.6 -3.4 233 1.2 8500 -4.8 23.4 355 47 24 8.8 4.8 5.2 41.3 -3.6 209 1.1 8250 -4.2 24.4 355 47 24 8.0 4.4 5.1 41.1 -3.7 183 0.9 8000 -3.6 25.5 355 47 24 10.6 5.8 5.0 41.0 -3.8 157 0.8 7750 -2.7 27.1 355 45 23 9.9 5.4 5.1 41.2 -3.7 124 0.6 7500 -2.2 28.0 355 44 23 6.8 3.8 4.9 40.9 -3.9 100 0.5 7250 -1.7 28.9 355 43 22 7.6 4.2 4.8 40.6 -4.1 77 0.4 7000 -1.1 30.0 355 41 21 7.6 4.2 4.6 40.3 -4.3 53 0.3 6750 -0.6 30.9 355 38 20 7.0 3.8 4.4 40.0 -4.5 30 0.2 6500 -0.1 31.8 355 36 18 6.2 3.4 4.2 39.5 -4.7 8 0.0 6250 0.3 32.5 355 33 17 6.7 3.7 3.9 39.1 -5.0 M M 6000 0.9 33.6 355 30 15 8.0 4.4 3.7 38.7 -5.2 M M 5750 1.5 34.7 355 25 13 7.7 4.2 3.6 38.5 -5.4 M M 5500 1.9 35.4 355 21 11 5.2 2.8 3.4 38.1 -5.7 M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 03/04/2025 at 0800 MST | 03/04/2025 at 1100 MST | CAPE... +0.7 LI... +4.8 | CAPE... +12.8 LI... +4.4 CINH... -13.4 K Index... +5.8 | CINH... -5.5 K Index... +7.5 | 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 -51.5 -60.7 255 19 10 4.1 2.2 | -50.3 -58.5 265 17 9 3.8 2.1 45000 -45.4 -49.7 245 20 10 4.2 2.3 | -44.4 -47.9 260 23 12 3.2 1.7 40000 -43.0 -45.4 245 11 5 1.3 0.7 | -44.6 -48.3 260 22 11 -0.2 -0.1 38000 -42.8 -45.0 260 8 4 -2.8 -1.5 | -44.9 -48.8 265 21 11 -2.0 -1.1 36000 -44.4 -47.9 305 12 6 -2.7 -1.5 | -46.1 -51.0 295 19 10 -2.0 -1.1 34000 -46.0 -50.8 320 20 10 -2.7 -1.5 | -47.2 -53.0 320 22 11 -1.9 -1.1 32000 -48.1 -54.6 330 22 12 -3.7 -2.0 | -48.1 -54.6 320 23 12 -1.3 -0.7 30000 -50.5 -58.9 340 23 12 -4.8 -2.6 | -49.0 -56.2 315 22 11 -2.2 -1.2 29000 -49.4 -56.9 340 23 12 7.1 3.9 | -47.9 -54.2 315 22 11 5.4 3.0 28000 -47.3 -53.1 335 24 12 7.1 3.9 | -46.3 -51.3 315 22 11 5.4 2.9 27000 -45.2 -49.4 335 25 13 7.1 3.9 | -44.7 -48.5 320 22 11 5.4 3.0 26000 -42.9 -45.2 335 25 13 8.6 4.7 | -42.8 -45.0 320 22 11 8.6 4.7 25000 -40.4 -40.7 335 24 12 8.5 4.6 | -40.3 -40.5 315 22 11 8.4 4.6 24000 -37.9 -36.2 335 23 12 8.5 4.6 | -37.8 -36.0 315 22 11 8.4 4.6 23000 -35.3 -31.5 335 22 12 9.3 5.1 | -35.3 -31.5 310 22 11 9.2 5.0 22000 -32.5 -26.5 340 23 12 9.2 5.1 | -32.5 -26.5 305 22 12 9.1 5.0 21000 -29.8 -21.6 340 23 12 9.2 5.0 | -29.8 -21.6 305 23 12 9.1 5.0 20000 -27.3 -17.1 345 24 12 7.1 3.9 | -27.3 -17.1 305 24 12 7.4 4.1 19500 -26.3 -15.3 345 25 13 7.1 3.9 | -26.2 -15.2 305 23 12 7.3 4.0 19000 -25.2 -13.4 345 25 13 7.1 3.9 | -25.2 -13.4 310 23 12 7.3 4.0 18500 -24.2 -11.6 350 26 13 7.1 3.9 | -24.1 -11.4 310 23 12 7.3 4.0 18000 -23.1 -9.6 350 26 13 7.3 4.0 | -23.0 -9.4 315 23 12 6.4 3.5 17500 -22.0 -7.6 345 26 14 7.7 4.2 | -22.2 -8.0 320 24 12 5.3 2.9 17000 -20.8 -5.4 345 26 14 8.0 4.4 | -21.4 -6.5 325 25 13 5.4 2.9 16500 -19.8 -3.6 340 27 14 4.9 2.7 | -20.6 -5.1 330 28 14 3.3 1.8 16000 -18.7 -1.7 340 29 15 5.0 2.8 | -20.1 -4.2 335 30 16 3.7 2.0 15500 -18.1 -0.6 340 31 16 3.5 1.9 | -19.4 -2.9 335 33 17 5.6 3.1 15000 -17.6 0.3 340 34 18 3.7 2.0 | -18.5 -1.3 340 35 18 5.5 3.0 14500 -17.0 1.4 345 37 19 4.0 2.2 | -17.7 0.1 340 37 19 6.4 3.5 14000 -16.5 2.3 345 39 20 3.9 2.1 | -16.7 1.9 340 39 20 6.3 3.4 13500 -15.8 3.6 345 42 21 5.0 2.7 | -15.7 3.7 340 40 21 7.4 4.1 13000 -15.1 4.8 345 43 22 5.0 2.7 | -14.6 5.7 340 42 22 7.4 4.1 12500 -14.2 6.4 345 44 23 7.6 4.2 | -13.5 7.7 340 44 23 7.9 4.3 12000 -13.1 8.4 345 44 22 8.1 4.4 | -12.3 9.9 335 45 23 7.9 4.3 11500 -11.9 10.6 345 43 22 8.1 4.5 | -11.2 11.8 335 46 23 8.2 4.5 11000 -10.7 12.7 345 44 23 8.2 4.5 | -9.9 14.2 340 45 23 8.4 4.6 10500 -9.5 14.9 345 45 23 7.6 4.2 | -8.8 16.2 340 45 23 6.3 3.5 10250 -8.9 16.0 350 44 23 7.4 4.1 | -8.4 16.9 340 44 23 6.6 3.6 10000 -8.4 16.9 350 44 23 7.9 4.3 | -7.9 17.8 340 44 22 5.9 3.2 9750 -7.8 18.0 350 44 23 7.9 4.3 | -7.5 18.5 345 43 22 4.7 2.6 9500 -7.2 19.0 350 44 23 7.1 3.9 | -7.2 19.0 345 40 21 4.8 2.6 9250 -6.7 19.9 350 44 22 7.9 4.3 | -6.9 19.6 345 38 19 4.0 2.2 9000 -6.2 20.8 355 43 22 5.4 3.0 | -6.6 20.1 350 35 18 7.5 4.1 8750 -5.8 21.6 355 43 22 6.0 3.3 | -5.9 21.4 350 34 17 10.0 5.5 8500 -5.2 22.6 355 43 22 9.0 5.0 | -5.2 22.6 350 33 17 8.6 4.7 8250 -4.6 23.7 355 42 22 8.0 4.4 | -4.6 23.7 355 32 16 8.4 4.6 8000 -4.0 24.8 355 41 21 9.0 5.0 | -3.9 25.0 355 31 16 10.7 5.9 7750 -3.3 26.1 355 40 21 8.6 4.7 | -3.0 26.6 355 31 16 11.1 6.1 7500 -2.8 27.0 355 39 20 7.6 4.1 | -2.3 27.9 355 30 16 8.7 4.8 7250 -2.2 28.0 355 38 20 7.7 4.2 | -1.7 28.9 355 30 15 9.6 5.3 7000 -1.6 29.1 350 37 19 8.5 4.6 | -0.9 30.4 355 30 15 12.0 6.6 6750 -1.0 30.2 350 35 18 7.1 3.9 | 0.0 32.0 355 29 15 10.6 5.8 6500 -0.6 30.9 350 32 17 5.1 2.8 | 0.7 33.3 355 29 15 7.3 4.0 6250 -0.2 31.6 350 30 15 6.2 3.4 | 1.3 34.3 355 28 15 10.5 5.8 6000 0.3 32.5 350 26 13 6.9 3.8 | 2.2 36.0 355 27 14 13.7 7.5 5750 0.8 33.4 345 21 11 7.1 3.9 | 3.2 37.8 355 26 13 10.4 5.7 5500 1.4 34.5 345 17 9 10.2 5.6 | 3.9 39.0 355 24 12 13.1 7.2 03/04/2025 at 1400 MST | 03/04/2025 at 1700 MST | CAPE... +5.6 LI... +2.6 | CAPE... +1.4 LI... +2.8 CINH... 0.0 K Index... +12.7 | CINH... -1.2 K Index... +16.1 | 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 -50.8 -59.4 260 16 8 4.0 2.2 | -50.6 -59.1 265 22 11 3.1 1.7 45000 -44.9 -48.8 260 20 10 4.2 2.3 | -46.1 -51.0 280 27 14 3.3 1.8 40000 -45.0 -49.0 290 30 15 -0.4 -0.2 | -46.9 -52.4 310 37 19 -0.8 -0.5 38000 -45.5 -49.9 295 34 17 -2.4 -1.3 | -47.6 -53.7 315 43 22 -1.7 -0.9 36000 -46.9 -52.4 305 33 17 -2.4 -1.3 | -48.6 -55.5 320 50 26 -1.7 -0.9 34000 -48.4 -55.1 315 34 18 -2.4 -1.3 | -49.6 -57.3 325 57 29 -1.9 -1.1 32000 -48.2 -54.8 320 37 19 1.1 0.6 | -48.3 -54.9 330 65 33 3.0 1.7 30000 -47.5 -53.5 325 41 21 0.9 0.5 | -46.5 -51.7 330 73 38 3.0 1.6 29000 -46.5 -51.7 325 40 20 4.2 2.3 | -44.9 -48.8 330 71 37 4.9 2.7 28000 -45.2 -49.4 325 38 20 4.2 2.3 | -43.5 -46.3 330 66 34 4.9 2.7 27000 -44.0 -47.2 330 36 19 4.2 2.3 | -42.0 -43.6 330 62 32 4.9 2.7 26000 -42.4 -44.3 330 35 18 7.9 4.3 | -40.4 -40.7 330 57 30 6.2 3.4 25000 -40.1 -40.2 330 35 18 7.7 4.2 | -38.5 -37.3 330 54 28 6.2 3.4 24000 -37.8 -36.0 330 36 18 7.7 4.2 | -36.7 -34.1 325 50 26 6.2 3.4 23000 -35.5 -31.9 330 36 19 7.8 4.3 | -34.7 -30.5 325 48 25 7.2 3.9 22000 -33.2 -27.8 330 37 19 7.8 4.3 | -32.6 -26.7 330 48 25 7.1 3.9 21000 -30.8 -23.4 335 37 19 7.8 4.3 | -30.5 -22.9 330 47 24 7.1 3.9 20000 -28.7 -19.7 335 38 20 6.8 3.8 | -28.4 -19.1 330 47 24 6.5 3.6 19500 -27.7 -17.9 335 39 20 6.8 3.7 | -27.5 -17.5 330 47 24 6.5 3.6 19000 -26.7 -16.1 335 39 20 6.8 3.7 | -26.5 -15.7 330 47 24 6.5 3.6 18500 -25.6 -14.1 335 40 21 6.8 3.8 | -25.5 -13.9 330 47 24 6.5 3.6 18000 -24.6 -12.3 335 41 21 7.0 3.8 | -24.6 -12.3 330 47 24 5.0 2.7 17500 -23.6 -10.5 335 41 21 7.2 3.9 | -24.0 -11.2 325 47 24 4.1 2.3 17000 -22.5 -8.5 335 42 21 7.2 3.9 | -23.4 -10.1 325 48 25 4.4 2.4 16500 -21.5 -6.7 335 42 22 6.4 3.5 | -22.6 -8.7 320 48 25 6.4 3.5 16000 -20.1 -4.2 335 43 22 6.4 3.5 | -21.7 -7.1 320 48 24 6.1 3.3 15500 -19.1 -2.4 335 43 22 6.4 3.5 | -20.7 -5.3 315 47 24 8.4 4.6 15000 -18.2 -0.8 335 44 23 6.4 3.5 | -18.8 -1.8 315 44 22 8.3 4.6 14500 -17.2 1.0 330 44 23 7.3 4.0 | -17.6 0.3 315 41 21 8.1 4.4 14000 -16.1 3.0 330 44 23 7.1 3.9 | -16.4 2.5 315 39 20 8.1 4.4 13500 -15.0 5.0 325 43 22 8.8 4.8 | -15.3 4.5 315 37 19 7.9 4.3 13000 -13.7 7.3 325 42 22 8.8 4.8 | -14.1 6.6 315 35 18 8.1 4.5 12500 -12.6 9.3 325 41 21 6.9 3.8 | -13.1 8.4 315 33 17 5.3 2.9 12000 -11.5 11.3 325 39 20 7.3 4.0 | -12.3 9.9 320 31 16 5.5 3.0 11500 -10.7 12.7 330 38 20 4.5 2.5 | -11.5 11.3 325 30 15 6.1 3.3 11000 -10.0 14.0 330 37 19 4.7 2.6 | -10.6 12.9 330 28 14 6.0 3.3 10500 -9.4 15.1 340 35 18 3.8 2.1 | -9.6 14.7 340 26 14 7.4 4.1 10250 -9.1 15.6 340 34 17 3.0 1.6 | -9.1 15.6 340 26 13 6.2 3.4 10000 -8.9 16.0 345 32 17 6.6 3.6 | -8.5 16.7 345 25 13 10.3 5.6 9750 -8.2 17.2 350 30 16 10.5 5.7 | -7.6 18.3 345 24 12 11.7 6.4 9500 -7.4 18.7 355 30 15 9.6 5.3 | -6.9 19.6 350 24 12 8.7 4.8 9250 -6.7 19.9 355 29 15 10.0 5.5 | -6.2 20.8 355 23 12 9.7 5.3 9000 -6.0 21.2 355 29 15 9.2 5.0 | -5.5 22.1 355 23 12 8.9 4.9 8750 -5.3 22.5 360 28 15 9.3 5.1 | -4.9 23.2 360 22 12 8.8 4.9 8500 -4.6 23.7 360 28 14 10.3 5.7 | -4.2 24.4 360 22 11 9.4 5.2 8250 -3.8 25.2 360 28 14 9.7 5.3 | -3.5 25.7 360 22 11 9.3 5.1 8000 -3.1 26.4 360 28 14 11.1 6.1 | -2.7 27.1 360 22 11 10.7 5.9 7750 -2.2 28.0 360 28 14 10.7 5.9 | -1.9 28.6 005 21 11 10.3 5.7 7500 -1.5 29.3 360 27 14 8.9 4.9 | -1.2 29.8 005 21 11 8.9 4.9 7250 -0.8 30.6 360 27 14 9.7 5.3 | -0.5 31.1 005 21 11 9.6 5.3 7000 -0.0 32.0 360 27 14 10.7 5.9 | 0.2 32.4 005 20 11 10.5 5.8 6750 0.8 33.4 360 27 14 10.4 5.7 | 1.0 33.8 005 20 10 9.5 5.2 6500 1.5 34.7 360 26 13 9.4 5.2 | 1.6 34.9 005 20 10 8.7 4.8 6250 2.2 36.0 360 26 13 10.8 5.9 | 2.3 36.1 005 19 10 10.0 5.5 6000 3.1 37.6 360 25 13 12.2 6.7 | 3.1 37.6 005 18 9 10.9 6.0 5750 4.0 39.2 360 24 12 10.3 5.7 | 3.9 39.0 005 17 9 9.7 5.3 5500 4.8 40.6 360 22 12 13.8 7.6 | 4.6 40.3 005 16 8 8.4 4.6 ________________________________________________________________________________ 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