Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
190 UXUS97 KBOU 021250 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 0649 MDT Thursday, May 2, 2024 This forecast is for Thursday, May 2, 2024: If the trigger temperature of 51.3 F/10.7 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 939 ft/min (4.8 m/s) Maximum height of thermals.................. 16360 ft MSL (11031 ft AGL) Forecast maximum temperature................... 63.0 F/17.7 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................. 13745 ft MSL (8416 ft AGL) Thermal soaring outlook for Friday 05/03....... Good Wave Soaring Index............................. Good Wave Soaring Index trend (to 1800 MDT)......... Little change Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1800 MDT)................ Weak PVA Potential height of wave....................... 34346 ft MSL (29017 ft AGL) Wave soaring outlook for Friday 05/03.......... Fair Remarks... An isolated shower or two this afternoon, cooler. Sunrise/Sunset.................... 05:57:38 / 19:55:08 MDT Total possible sunshine........... 13 hr 57 min 29 sec (837 min 29 sec) Altitude of sun at 12:56:23 MDT... 65.92 degrees Upper air data from numerical model forecast valid on 05/02/2024 at 0600 MDT Freezing level.................. 8628 ft MSL (3299 ft AGL) Convective condensation level... 13482 ft MSL (8153 ft AGL) Lifted condensation level....... 14983 ft MSL (9654 ft AGL) Lifted index.................... +0.8 K index......................... -0.7 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 -53.9 -65.0 240 43 22 1.5 0.8 M M M M M 45000 -51.6 -60.9 235 52 27 0.5 0.3 M M M M M 40000 -51.5 -60.7 240 64 33 0.0 0.0 M M M M M 38000 -51.3 -60.3 240 70 36 0.7 0.4 M M M M M 36000 -50.9 -59.6 235 77 40 0.7 0.4 M M M M M 34000 -50.4 -58.7 235 85 44 2.3 1.2 M M M M M 32000 -47.9 -54.2 235 77 40 3.8 2.1 M M M M M 30000 -45.4 -49.7 240 70 36 6.7 3.7 30.8 87.4 10.2 M M 29000 -43.5 -46.3 240 68 35 6.4 3.5 29.3 84.7 9.2 M M 28000 -41.6 -42.9 245 65 34 6.4 3.5 28.0 82.4 8.3 M M 27000 -39.7 -39.5 245 63 33 6.3 3.5 26.8 80.3 7.5 M M 26000 -37.4 -35.3 250 63 32 8.0 4.4 25.9 78.7 6.9 M M 25000 -35.0 -31.0 250 62 32 8.0 4.4 25.3 77.5 6.4 M M 24000 -32.6 -26.7 250 62 32 8.0 4.4 24.7 76.5 6.0 M M 23000 -30.1 -22.2 250 61 31 8.0 4.4 24.0 75.3 5.6 M M 22000 -27.7 -17.9 245 60 31 8.1 4.4 23.4 74.1 5.1 M M 21000 -25.3 -13.5 245 59 30 7.8 4.3 22.9 73.2 4.7 M M 20000 -23.3 -9.9 250 58 30 6.6 3.6 21.7 71.1 3.8 M M 19500 -22.3 -8.1 250 58 30 6.6 3.6 21.2 70.1 3.3 M M 19000 -21.3 -6.3 250 58 30 6.6 3.6 20.6 69.2 2.9 M M 18500 -20.3 -4.5 250 58 30 6.6 3.6 20.1 68.2 2.5 M M 18000 -19.4 -2.9 250 56 29 6.0 3.3 19.5 67.2 2.0 M M 17500 -18.0 -0.4 255 53 28 6.1 3.3 18.6 65.5 1.2 M M 17000 -17.1 1.2 255 52 27 6.0 3.3 18.0 64.3 0.6 M M 16500 -16.2 2.8 255 50 26 6.0 3.3 17.3 63.2 0.0 M M 16000 -15.4 4.3 260 49 25 6.0 3.3 16.7 62.0 -0.5 900 4.6 15500 -14.5 5.9 260 46 24 6.0 3.3 16.0 60.9 -1.1 859 4.4 15000 -13.6 7.5 260 44 23 6.1 3.3 15.4 59.8 -1.7 817 4.2 14500 -12.7 9.1 260 41 21 6.2 3.4 14.8 58.7 -2.3 776 3.9 14000 -11.8 10.8 260 38 19 6.6 3.6 14.2 57.6 -2.8 734 3.7 13500 -10.7 12.7 260 35 18 7.2 4.0 13.8 56.8 -3.3 687 3.5 13000 -9.7 14.5 260 31 16 7.6 4.1 13.4 56.1 -3.7 641 3.3 12500 -8.5 16.7 260 29 15 8.3 4.6 13.1 55.6 -4.0 591 3.0 12000 -7.3 18.9 260 27 14 8.4 4.6 12.9 55.2 -4.3 540 2.7 11500 -6.0 21.2 255 25 13 8.6 4.7 12.7 54.8 -4.5 487 2.5 11000 -4.8 23.4 255 23 12 8.1 4.4 12.5 54.5 -4.7 435 2.2 10500 -3.8 25.2 250 20 10 6.7 3.7 12.1 53.7 -5.2 390 2.0 10250 -3.3 26.1 245 19 10 6.0 3.3 11.8 53.3 -5.5 369 1.9 10000 -2.8 27.0 245 18 9 9.1 5.0 11.6 52.8 -5.8 347 1.8 9750 -2.1 28.2 245 16 8 8.9 4.9 11.6 52.9 -5.7 317 1.6 9500 -1.6 29.1 245 15 8 5.6 3.1 11.4 52.5 -6.0 295 1.5 9250 -1.1 30.0 240 13 7 6.5 3.6 11.1 52.0 -6.3 274 1.4 9000 -0.7 30.7 240 12 6 5.8 3.2 10.8 51.5 -6.6 253 1.3 8750 -0.3 31.5 235 11 6 5.8 3.2 10.5 50.9 -6.9 233 1.2 8500 0.2 32.4 235 10 5 6.1 3.3 10.2 50.4 -7.2 213 1.1 8250 0.6 33.1 235 8 4 6.0 3.3 9.9 49.9 -7.5 192 1.0 8000 1.1 34.0 235 7 4 6.0 3.3 9.6 49.3 -7.8 171 0.9 7750 1.5 34.7 225 7 3 4.9 2.7 9.3 48.8 -8.2 151 0.8 7500 1.8 35.2 225 5 2 4.4 2.4 8.9 48.0 -8.6 134 0.7 7250 2.1 35.8 225 3 2 4.1 2.2 8.5 47.3 -9.0 117 0.6 7000 2.4 36.3 190 3 1 2.6 1.5 8.0 46.4 -9.5 102 0.5 6750 2.6 36.7 155 3 2 5.3 2.9 7.5 45.5 -10.0 88 0.4 6500 3.1 37.6 125 3 2 6.5 3.6 7.3 45.1 -10.3 65 0.3 6250 3.5 38.3 120 4 2 4.0 2.2 6.9 44.5 -10.7 47 0.2 6000 3.7 38.7 120 5 3 3.1 1.7 6.5 43.6 -11.2 33 0.2 5750 4.0 39.2 125 6 3 4.6 2.5 6.0 42.8 -11.7 18 0.1 5500 4.2 39.6 135 5 3 0.7 0.4 5.5 42.0 -12.3 4 0.0 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 05/02/2024 at 0900 MDT | 05/02/2024 at 1200 MDT | CAPE... +2.0 LI... +5.5 | CAPE... +0.8 LI... +2.9 CINH... -0.1 K Index... +0.6 | CINH... -1.9 K Index... +7.0 | 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 -53.2 -63.8 240 41 21 1.2 0.6 | -53.0 -63.4 240 41 21 1.2 0.6 45000 -51.4 -60.5 235 55 28 0.5 0.3 | -51.2 -60.2 240 57 29 0.2 0.1 40000 -51.5 -60.7 245 65 33 -0.0 -0.0 | -51.9 -61.4 245 65 33 -0.5 -0.3 38000 -51.7 -61.1 245 68 35 -1.1 -0.6 | -52.3 -62.1 245 69 35 -1.0 -0.6 36000 -52.3 -62.1 245 69 35 -1.0 -0.6 | -52.9 -63.2 250 73 38 -1.0 -0.6 34000 -53.0 -63.4 245 70 36 1.9 1.0 | -53.5 -64.3 255 78 40 2.7 1.5 32000 -49.5 -57.1 250 72 37 5.1 2.8 | -49.4 -56.9 255 78 40 6.1 3.3 30000 -46.2 -51.2 255 74 38 8.8 4.8 | -45.6 -50.1 260 78 40 8.3 4.6 29000 -43.7 -46.7 255 73 38 8.5 4.7 | -43.1 -45.6 260 78 40 8.1 4.5 28000 -41.1 -42.0 260 73 37 8.5 4.7 | -40.7 -41.3 260 77 39 8.1 4.5 27000 -38.6 -37.5 260 72 37 8.4 4.6 | -38.2 -36.8 260 76 39 8.1 4.4 26000 -36.3 -33.3 260 71 36 7.2 3.9 | -36.0 -32.8 255 74 38 7.2 3.9 25000 -34.2 -29.6 260 69 35 7.2 3.9 | -33.9 -29.0 255 73 37 7.2 4.0 24000 -32.0 -25.6 260 67 35 7.1 3.9 | -31.7 -25.1 255 71 36 7.2 4.0 23000 -29.7 -21.5 260 66 34 8.1 4.5 | -29.6 -21.3 255 69 35 7.3 4.0 22000 -27.2 -17.0 260 65 33 8.1 4.5 | -27.4 -17.3 255 67 34 7.3 4.0 21000 -24.8 -12.6 260 64 33 7.9 4.3 | -25.2 -13.4 255 65 33 7.1 3.9 20000 -22.7 -8.9 260 62 32 7.0 3.9 | -23.2 -9.8 255 61 31 6.7 3.7 19500 -21.6 -6.9 260 61 32 7.0 3.9 | -22.2 -8.0 255 59 31 6.7 3.7 19000 -20.6 -5.1 260 61 31 7.0 3.9 | -21.2 -6.2 255 57 30 6.7 3.7 18500 -19.5 -3.1 260 60 31 7.0 3.8 | -20.2 -4.4 260 56 29 6.7 3.7 18000 -18.5 -1.3 265 59 30 6.0 3.3 | -19.2 -2.6 260 53 28 6.5 3.6 17500 -17.2 1.0 265 57 29 6.0 3.3 | -18.2 -0.8 260 51 26 6.5 3.6 17000 -16.4 2.5 265 56 29 5.2 2.9 | -17.3 0.9 260 49 25 6.5 3.6 16500 -15.6 3.9 265 54 28 5.4 2.9 | -16.3 2.7 260 46 24 6.5 3.5 16000 -14.9 5.2 265 52 27 4.5 2.5 | -14.9 5.2 260 43 22 6.5 3.5 15500 -14.2 6.4 265 49 25 4.5 2.5 | -13.9 7.0 260 41 21 6.5 3.5 15000 -13.5 7.7 265 46 24 5.3 2.9 | -12.9 8.8 260 39 20 6.6 3.6 14500 -12.7 9.1 265 43 22 5.7 3.2 | -12.0 10.4 255 36 19 6.7 3.7 14000 -11.8 10.8 265 39 20 6.2 3.4 | -11.0 12.2 255 33 17 7.2 4.0 13500 -10.8 12.6 265 37 19 6.7 3.7 | -9.8 14.4 255 31 16 7.7 4.2 13000 -9.8 14.4 265 34 17 6.8 3.8 | -8.7 16.3 255 28 14 7.8 4.3 12500 -8.8 16.2 265 31 16 7.1 3.9 | -7.5 18.5 255 25 13 8.0 4.4 12000 -7.7 18.1 265 28 14 7.2 4.0 | -6.3 20.7 255 23 12 7.9 4.3 11500 -6.6 20.1 265 25 13 7.5 4.1 | -5.2 22.6 255 20 10 7.6 4.2 11000 -5.5 22.1 265 22 11 7.5 4.1 | -4.0 24.8 255 18 9 6.7 3.7 10500 -4.4 24.1 265 19 10 7.4 4.0 | -3.2 26.2 250 15 8 4.8 2.6 10250 -3.9 25.0 260 18 9 8.4 4.6 | -2.9 26.8 250 13 7 6.8 3.7 10000 -3.3 26.1 260 16 8 4.5 2.5 | -2.2 28.0 245 11 6 9.5 5.2 9750 -3.1 26.4 260 14 7 5.0 2.7 | -1.6 29.1 240 9 5 8.0 4.4 9500 -2.5 27.5 255 13 7 9.2 5.0 | -1.1 30.0 235 7 4 7.3 4.0 9250 -1.9 28.6 250 12 6 8.1 4.4 | -0.5 31.1 225 6 3 6.8 3.7 9000 -1.4 29.5 245 10 5 6.0 3.3 | -0.1 31.8 215 4 2 5.7 3.1 8750 -1.0 30.2 240 9 5 4.6 2.5 | 0.4 32.7 210 4 2 8.1 4.4 8500 -0.7 30.7 230 8 4 5.3 2.9 | 1.1 34.0 195 3 1 10.1 5.5 8250 -0.3 31.5 220 7 3 4.9 2.7 | 1.8 35.2 175 2 1 8.6 4.7 8000 0.0 32.0 210 6 3 4.4 2.4 | 2.3 36.1 160 2 1 7.2 4.0 7750 0.4 32.7 195 5 3 5.0 2.8 | 2.9 37.2 145 3 1 9.2 5.1 7500 0.8 33.4 185 4 2 5.8 3.2 | 3.7 38.7 135 3 1 11.4 6.3 7250 1.2 34.2 165 3 2 4.9 2.7 | 4.5 40.1 125 3 2 8.7 4.8 7000 1.5 34.7 150 4 2 2.9 1.6 | 5.0 41.0 120 4 2 5.7 3.1 6750 1.8 35.2 140 4 2 7.4 4.1 | 5.5 41.9 115 4 2 11.5 6.3 6500 2.5 36.5 130 4 2 10.2 5.6 | 6.6 43.9 110 4 2 13.9 7.6 6250 3.1 37.6 125 5 2 7.4 4.1 | 7.4 45.3 110 4 2 9.9 5.5 6000 3.6 38.5 125 5 3 6.5 3.6 | 8.1 46.6 105 4 2 8.6 4.7 5750 4.1 39.4 125 5 3 10.0 5.5 | 8.9 48.0 105 4 2 12.1 6.6 5500 5.2 41.4 125 4 2 19.6 10.8 | 10.1 50.2 105 4 2 24.0 13.2 05/02/2024 at 1500 MDT | 05/02/2024 at 1800 MDT | CAPE... +31.4 LI... 0.0 | CAPE... +62.6 LI... -0.6 CINH... -17.4 K Index... +17.2 | CINH... -31.4 K Index... +18.1 | 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 -53.3 -63.9 245 43 22 2.2 1.2 | -52.4 -62.3 245 39 20 2.3 1.2 45000 -49.8 -57.6 245 52 27 -0.7 -0.4 | -49.1 -56.4 255 48 25 -2.1 -1.1 40000 -53.5 -64.3 255 65 33 -2.5 -1.4 | -57.9 -72.2 265 66 34 -5.8 -3.2 38000 -54.3 -65.7 260 71 37 0.5 0.3 | -58.7 -73.7 265 72 37 4.6 2.5 36000 -54.0 -65.2 270 79 41 0.4 0.2 | -56.0 -68.8 270 75 39 4.5 2.5 34000 -53.6 -64.5 275 87 45 4.8 2.6 | -53.1 -63.6 270 78 40 6.9 3.8 32000 -49.1 -56.4 270 82 42 6.8 3.7 | -48.3 -54.9 270 75 38 7.1 3.9 30000 -44.8 -48.6 265 79 41 8.2 4.5 | -44.0 -47.2 270 72 37 7.5 4.1 29000 -42.4 -44.3 265 78 40 8.2 4.5 | -41.8 -43.2 270 69 36 7.5 4.1 28000 -39.9 -39.8 265 77 40 8.2 4.5 | -39.5 -39.1 265 67 35 7.5 4.1 27000 -37.5 -35.5 265 77 39 8.0 4.4 | -37.3 -35.1 265 65 33 7.6 4.2 26000 -35.3 -31.5 260 75 39 7.0 3.9 | -34.9 -30.8 265 64 33 7.9 4.3 25000 -33.2 -27.8 260 73 38 7.0 3.9 | -32.5 -26.5 265 63 33 7.9 4.3 24000 -31.1 -24.0 260 72 37 7.2 3.9 | -30.2 -22.4 265 63 32 7.8 4.3 23000 -29.3 -20.7 260 68 35 6.0 3.3 | -28.2 -18.8 265 60 31 6.2 3.4 22000 -27.5 -17.5 260 64 33 6.1 3.3 | -26.4 -15.5 260 58 30 6.3 3.4 21000 -25.7 -14.3 255 61 31 6.4 3.5 | -24.5 -12.1 260 55 28 6.4 3.5 20000 -23.7 -10.7 255 56 29 6.8 3.7 | -22.6 -8.7 260 50 26 6.5 3.6 19500 -22.7 -8.9 255 54 28 6.8 3.7 | -21.6 -6.9 255 47 24 6.5 3.6 19000 -21.7 -7.1 255 51 26 6.8 3.8 | -20.7 -5.3 255 45 23 6.5 3.6 18500 -20.6 -5.1 255 49 25 7.0 3.8 | -19.7 -3.5 255 42 22 6.9 3.8 18000 -19.6 -3.3 250 46 24 7.6 4.2 | -18.6 -1.5 250 40 20 7.6 4.2 17500 -18.4 -1.1 250 44 23 7.5 4.1 | -17.5 0.5 250 37 19 7.6 4.2 17000 -17.3 0.9 250 41 21 7.7 4.2 | -15.7 3.7 250 34 18 8.1 4.4 16500 -15.6 3.9 250 37 19 7.6 4.2 | -14.5 5.9 245 32 17 8.1 4.4 16000 -14.4 6.1 250 35 18 8.6 4.7 | -13.3 8.1 245 30 16 8.7 4.8 15500 -13.1 8.4 250 32 17 8.5 4.7 | -12.0 10.4 245 29 15 8.7 4.8 15000 -11.8 10.8 245 30 15 8.6 4.7 | -10.7 12.7 250 27 14 8.7 4.8 14500 -10.6 12.9 245 27 14 8.6 4.7 | -9.4 15.1 250 25 13 8.7 4.8 14000 -9.3 15.3 245 25 13 8.5 4.7 | -8.1 17.4 250 24 12 8.7 4.8 13500 -8.0 17.6 245 23 12 8.4 4.6 | -6.8 19.8 250 22 11 8.7 4.8 13000 -6.8 19.8 245 21 11 8.3 4.6 | -5.5 22.1 250 20 10 8.6 4.7 12500 -5.6 21.9 245 18 9 8.2 4.5 | -4.3 24.3 250 18 9 8.5 4.7 12000 -4.3 24.3 240 16 8 8.1 4.5 | -3.0 26.6 250 17 8 8.1 4.4 11500 -3.1 26.4 240 13 7 8.0 4.4 | -1.9 28.6 250 14 7 7.6 4.2 11000 -2.0 28.4 235 11 6 7.3 4.0 | -0.8 30.6 250 12 6 7.2 4.0 10500 -1.0 30.2 235 8 4 5.6 3.1 | 0.2 32.4 255 10 5 6.0 3.3 10250 -0.5 31.1 235 7 4 9.7 5.3 | 0.7 33.3 255 9 5 10.6 5.8 10000 0.4 32.7 235 6 3 11.5 6.3 | 1.7 35.1 260 8 4 12.0 6.6 9750 1.0 33.8 235 5 3 8.3 4.6 | 2.4 36.3 260 7 4 8.3 4.6 9500 1.7 35.1 235 4 2 9.3 5.1 | 3.1 37.6 260 6 3 9.7 5.3 9250 2.3 36.1 230 3 2 7.8 4.3 | 3.8 38.8 265 6 3 7.9 4.3 9000 2.9 37.2 235 2 1 7.7 4.2 | 4.3 39.7 265 5 3 7.5 4.1 8750 3.6 38.5 235 2 1 10.1 5.5 | 4.9 40.8 265 5 3 9.5 5.2 8500 4.3 39.7 230 2 1 11.0 6.0 | 5.6 42.1 270 4 2 10.0 5.5 8250 5.1 41.2 220 1 1 9.7 5.3 | 6.4 43.5 270 3 2 9.1 5.0 8000 5.8 42.4 220 1 0 8.2 4.5 | 7.0 44.6 270 3 2 8.0 4.4 7750 6.4 43.5 000 0 0 9.7 5.3 | 7.6 45.7 275 3 2 8.9 4.9 7500 7.2 45.0 000 0 0 11.5 6.3 | 8.3 46.9 275 2 1 10.0 5.5 7250 8.0 46.4 000 0 0 9.1 5.0 | 9.0 48.2 275 1 1 8.2 4.5 7000 8.6 47.5 065 1 0 6.9 3.8 | 9.5 49.1 280 1 1 6.5 3.6 6750 9.2 48.6 055 1 1 11.0 6.0 | 10.1 50.2 290 1 1 9.9 5.4 6500 10.2 50.4 065 1 1 12.8 7.0 | 10.9 51.6 320 1 0 11.6 6.3 6250 11.0 51.8 065 2 1 10.2 5.6 | 11.7 53.1 000 0 0 9.7 5.3 6000 11.8 53.2 055 2 1 9.4 5.1 | 12.4 54.3 005 1 0 9.2 5.0 5750 12.5 54.5 050 3 1 10.5 5.8 | 13.1 55.6 005 1 0 9.9 5.4 5500 13.5 56.3 060 2 1 19.0 10.4 | 14.0 57.2 055 1 1 13.4 7.4 ________________________________________________________________________________ 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