Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
548 UXUS97 KGJT 081306 SRGGJT Soaring Forecast National Weather Service Grand Junction, Colorado 606 AM MST Sunday, December 8, 2024 This forecast is for Sunday, December 8, 2024: If the trigger temperature of 55.8 F/13.2 C is reached...then Thermal Soaring Index....................... Fair Maximum rate of lift........................ 209 ft/min (1.1 m/s) Maximum height of thermals.................. 7314 ft MSL (2475 ft AGL) Forecast maximum temperature................... 48.0 F/9.3 C Time of trigger temperature.................... None 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................. 6587 ft MSL (1747 ft AGL) Thermal soaring outlook for Monday 12/09....... Fair Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 07:21:29 / 16:51:17 MST Total possible sunshine........... 9 hr 29 min 48 sec (569 min 48 sec) Altitude of sun at 12:06:23 MST... 28.04 degrees Upper air data from rawinsonde observation taken on 12/08/2024 at 0500 MST Freezing level.................. 5176 ft MSL (337 ft AGL) Additional freezing level....... 11793 ft MSL (6954 ft AGL) Convective condensation level... 21207 ft MSL (16368 ft AGL) Lifted condensation level....... 12675 ft MSL (7836 ft AGL) Lifted index.................... +15.6 K index......................... -1.7 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 -61.9 -79.4 265 46 24 -5.9 -3.3 98.0 208.4 50.7 M M 45000 -60.1 -76.2 285 52 27 -7.0 -3.8 75.1 167.1 40.5 M M 40000 -64.4 -83.9 290 36 19 8.7 4.8 45.0 113.0 23.7 M M 38000 -59.0 -74.2 285 33 17 8.2 4.5 44.3 111.8 23.9 M M 36000 -54.3 -65.7 280 32 16 8.9 4.9 42.6 108.8 23.4 M M 34000 -48.7 -55.7 280 33 17 8.3 4.6 42.2 108.0 23.7 M M 32000 -44.0 -47.2 275 32 16 9.3 5.1 40.7 105.2 23.2 M M 30000 -38.0 -36.4 275 32 16 9.0 4.9 39.9 103.8 23.3 M M 29000 -35.3 -31.5 275 28 14 8.2 4.5 39.7 103.4 23.4 M M 28000 -33.1 -27.6 275 30 15 7.3 4.0 38.7 101.7 22.9 M M 27000 -30.8 -23.4 280 29 15 7.6 4.2 37.9 100.2 22.6 M M 26000 -29.0 -20.2 275 26 13 6.2 3.4 36.6 97.8 21.8 M M 25000 -27.0 -16.6 290 27 14 7.2 4.0 35.4 95.8 21.1 M M 24000 -25.6 -14.1 290 27 14 7.6 4.2 33.6 92.4 19.8 M M 23000 -23.1 -9.6 295 29 15 9.3 5.1 33.0 91.4 19.6 M M 22000 -20.5 -4.9 295 31 16 8.1 4.5 32.7 90.9 19.6 M M 21000 -18.0 -0.4 295 30 16 8.6 4.7 32.3 90.1 19.4 M M 20000 -15.4 4.3 295 29 15 8.2 4.5 31.8 89.3 19.2 M M 19500 -14.2 6.4 300 28 15 8.0 4.4 31.5 88.7 19.0 M M 19000 -13.1 8.4 300 27 14 8.0 4.4 31.2 88.2 18.9 M M 18500 -11.9 10.6 300 24 12 8.0 4.4 30.9 87.6 18.7 M M 18000 -10.8 12.6 295 22 11 7.1 3.9 30.5 87.0 18.5 M M 17500 -9.8 14.4 295 21 11 7.0 3.8 30.0 86.0 18.1 M M 17000 -8.6 16.5 295 22 11 7.5 4.1 29.6 85.3 17.9 M M 16500 -7.0 19.4 295 21 11 5.3 2.9 28.9 84.1 17.5 M M 16000 -6.3 20.7 300 20 10 4.8 2.6 28.1 82.6 16.8 M M 15500 -5.6 21.9 295 19 10 5.0 2.7 27.3 81.1 16.1 M M 15000 -4.9 23.2 295 21 11 4.8 2.7 26.5 79.7 15.4 M M 14500 -4.2 24.4 300 24 12 5.0 2.8 25.6 78.2 14.7 M M 14000 -3.5 25.7 300 25 13 5.2 2.8 24.9 76.8 14.1 M M 13500 -2.8 27.0 300 25 13 5.1 2.8 24.1 75.4 13.4 M M 13000 -2.2 28.0 305 23 12 2.4 1.3 23.2 73.7 12.6 M M 12500 -1.4 29.5 305 22 11 7.4 4.1 22.3 72.2 12.0 M M 12000 -0.3 31.5 305 18 9 7.3 4.0 22.0 71.5 11.7 M M 11500 0.7 33.3 280 13 7 6.5 3.5 21.5 70.7 11.3 M M 11000 1.7 35.1 250 12 6 7.5 4.1 21.0 69.7 10.9 M M 10500 2.4 36.3 250 12 6 1.0 0.5 20.2 68.3 10.3 M M 10250 2.4 36.3 250 15 8 -7.0 -3.8 19.3 66.7 9.5 M M 10000 1.7 35.1 250 16 8 -8.0 -4.4 17.7 63.9 8.1 M M 9750 1.4 34.5 260 14 7 -2.9 -1.6 16.6 61.9 7.1 M M 9500 1.1 34.0 260 15 8 -1.9 -1.0 15.6 60.1 6.1 M M 9250 1.1 34.0 250 11 6 -0.0 -0.0 14.8 58.7 5.4 M M 9000 1.1 34.0 225 8 4 -0.4 -0.2 14.0 57.2 4.7 M M 8750 1.1 34.0 220 7 4 1.3 0.7 13.3 55.9 4.0 M M 8500 1.2 34.2 225 7 4 3.1 1.7 12.7 54.8 3.4 M M 8250 1.4 34.5 225 7 3 -0.6 -0.3 12.1 53.8 2.8 M M 8000 1.2 34.2 210 7 4 -0.5 -0.3 11.2 52.1 1.9 M M 7750 1.4 34.5 195 8 4 4.4 2.4 10.6 51.1 1.4 M M 7500 1.6 34.9 175 9 5 0.4 0.2 10.1 50.2 0.8 M M 7250 1.4 34.5 165 11 6 -3.0 -1.6 9.2 48.6 -0.1 209 1.1 7000 1.2 34.2 155 13 6 -1.7 -0.9 8.3 46.9 -1.0 207 1.1 6750 1.0 33.8 155 13 7 -4.1 -2.3 7.4 45.2 -1.9 206 1.0 6500 0.5 32.9 145 12 6 -9.8 -5.4 6.1 42.9 -3.1 213 1.1 6250 0.0 32.0 140 12 6 0.4 0.2 4.8 40.6 -4.4 221 1.1 6000 0.6 33.1 130 12 6 9.3 5.1 4.6 40.3 -4.6 197 1.0 5750 1.1 34.0 135 11 5 8.4 4.6 4.5 40.0 -4.8 174 0.9 5500 1.7 35.1 130 10 5 3.5 1.9 4.3 39.8 -5.0 150 0.8 5250 1.2 34.2 140 9 4 -16.6 -9.1 3.1 37.7 -6.2 156 0.8 5000 -0.7 30.7 150 8 4 -33.1 -18.1 0.4 32.8 -8.9 207 1.1 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 12/08/2024 at 0800 MST | 12/08/2024 at 1100 MST | CAPE... 0.0 LI... +6.4 | CAPE... 0.0 LI... +6.4 CINH... -0.1 K Index... +5.3 | CINH... -0.2 K Index... +3.7 | 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 -62.4 -80.3 260 44 22 1.9 1.1 | -62.2 -80.0 260 57 29 2.1 1.2 45000 -59.7 -75.5 265 49 25 -1.2 -0.7 | -59.0 -74.2 260 57 29 -1.0 -0.6 40000 -62.5 -80.5 270 49 25 -1.9 -1.1 | -62.0 -79.6 265 65 34 -2.0 -1.1 38000 -60.1 -76.2 270 49 25 8.0 4.4 | -60.0 -76.0 265 66 34 7.4 4.1 36000 -54.7 -66.5 265 48 25 8.0 4.4 | -55.6 -68.1 265 64 33 7.4 4.1 34000 -49.8 -57.6 260 49 25 8.4 4.6 | -50.4 -58.7 265 62 32 8.1 4.5 32000 -44.8 -48.6 265 50 26 8.4 4.6 | -45.5 -49.9 265 61 31 8.1 4.5 30000 -39.8 -39.6 270 50 26 8.0 4.4 | -40.7 -41.3 270 58 30 7.9 4.3 29000 -37.4 -35.3 270 49 25 8.0 4.4 | -38.4 -37.1 270 56 29 7.8 4.3 28000 -35.1 -31.2 275 48 25 8.0 4.4 | -36.1 -33.0 270 54 28 7.8 4.3 27000 -32.7 -26.9 275 47 24 7.0 3.8 | -33.8 -28.8 275 51 26 7.0 3.8 26000 -30.7 -23.3 280 44 23 6.9 3.8 | -31.7 -25.1 275 48 25 6.8 3.7 25000 -28.6 -19.5 280 42 22 6.9 3.8 | -29.7 -21.5 280 45 23 6.8 3.7 24000 -26.6 -15.9 285 40 21 7.0 3.8 | -27.7 -17.9 280 42 21 7.1 3.9 23000 -24.0 -11.2 285 38 19 7.0 3.9 | -25.4 -13.7 285 39 20 7.6 4.2 22000 -21.9 -7.4 290 36 18 7.0 3.9 | -23.1 -9.6 285 37 19 7.6 4.2 21000 -19.7 -3.5 295 34 18 7.9 4.3 | -20.2 -4.4 285 35 18 7.8 4.3 20000 -17.4 0.7 295 33 17 7.8 4.3 | -17.9 -0.2 285 34 18 7.8 4.3 19500 -16.3 2.7 295 33 17 7.8 4.3 | -16.7 1.9 285 34 18 7.8 4.3 19000 -15.1 4.8 300 33 17 7.9 4.3 | -15.6 3.9 285 34 17 7.9 4.3 18500 -14.0 6.8 300 33 17 7.2 4.0 | -14.5 5.9 285 34 17 6.9 3.8 18000 -12.9 8.8 300 33 17 7.3 4.0 | -13.4 7.9 290 34 17 6.9 3.8 17500 -11.8 10.8 300 33 17 7.2 3.9 | -12.4 9.7 290 34 17 6.7 3.7 17000 -10.8 12.6 305 32 17 7.1 3.9 | -11.5 11.3 290 34 17 6.3 3.5 16500 -9.8 14.4 305 32 16 7.1 3.9 | -10.6 12.9 290 33 17 6.4 3.5 16000 -8.7 16.3 305 31 16 7.1 3.9 | -9.7 14.5 290 33 17 5.7 3.1 15500 -7.7 18.1 305 31 16 7.1 3.9 | -8.9 16.0 290 33 17 5.8 3.2 15000 -6.6 20.1 310 30 15 6.9 3.8 | -8.1 17.4 290 32 16 5.6 3.1 14500 -5.6 21.9 310 29 15 6.8 3.7 | -7.3 18.9 290 31 16 5.5 3.0 14000 -4.6 23.7 310 28 14 6.6 3.6 | -6.5 20.3 290 30 16 5.4 3.0 13500 -3.6 25.5 310 26 14 6.4 3.5 | -5.8 21.6 290 29 15 5.3 2.9 13000 -2.7 27.1 310 25 13 5.9 3.2 | -5.0 23.0 295 27 14 5.3 2.9 12500 -1.8 28.8 310 24 12 5.2 2.8 | -4.2 24.4 295 26 13 5.2 2.9 12000 -1.0 30.2 305 22 11 4.5 2.5 | -3.4 25.9 295 25 13 5.1 2.8 11500 -0.5 31.1 305 21 11 2.7 1.5 | -2.7 27.1 295 23 12 4.8 2.6 11000 -0.1 31.8 300 19 10 2.2 1.2 | -1.9 28.6 295 22 11 4.2 2.3 10500 0.1 32.2 300 17 9 0.9 0.5 | -1.5 29.3 295 20 10 2.8 1.5 10250 0.1 32.2 295 16 8 1.1 0.6 | -1.2 29.8 295 20 10 2.8 1.5 10000 0.2 32.4 295 15 8 0.7 0.4 | -1.0 30.2 295 19 10 3.1 1.7 9750 0.3 32.5 290 14 7 0.7 0.4 | -0.8 30.6 290 17 9 2.4 1.3 9500 0.3 32.5 285 13 7 1.0 0.6 | -0.7 30.7 290 16 8 1.6 0.9 9250 0.4 32.7 285 12 6 1.0 0.5 | -0.5 31.1 290 14 7 1.8 1.0 9000 0.4 32.7 280 11 6 0.8 0.4 | -0.4 31.3 285 13 7 2.3 1.2 8750 0.5 32.9 275 10 5 1.0 0.5 | -0.2 31.6 280 12 6 2.5 1.3 8500 0.6 33.1 270 9 5 1.4 0.8 | -0.0 32.0 280 11 6 2.1 1.1 8250 0.7 33.3 260 7 4 0.3 0.1 | 0.1 32.2 275 10 5 2.2 1.2 8000 0.7 33.3 255 6 3 0.3 0.2 | 0.3 32.5 270 9 5 2.2 1.2 7750 0.8 33.4 245 5 2 0.8 0.4 | 0.7 33.3 265 7 4 3.8 2.1 7500 0.8 33.4 230 4 2 1.0 0.6 | 0.9 33.6 260 6 3 2.5 1.4 7250 0.9 33.6 220 3 2 1.1 0.6 | 1.0 33.8 260 5 3 0.4 0.2 7000 1.0 33.8 205 3 2 2.4 1.3 | 1.1 34.0 260 4 2 3.6 1.9 6750 1.2 34.2 195 3 2 2.7 1.5 | 1.5 34.7 255 3 2 6.1 3.4 6500 1.3 34.3 185 3 1 0.2 0.1 | 1.9 35.4 250 2 1 5.3 2.9 6250 1.2 34.2 170 2 1 -1.8 -1.0 | 2.3 36.1 255 2 1 4.3 2.4 6000 1.2 34.2 155 2 1 2.7 1.5 | 2.7 36.9 270 1 1 8.1 4.5 5750 1.4 34.5 125 2 1 -1.9 -1.0 | 3.6 38.5 255 1 1 17.6 9.6 5500 -1.3 29.7 090 1 1 -93.0 -51.1 | 4.6 40.3 275 1 0 0.9 0.5 5250 M M M M M M M | M M M M M M M 5000 M M M M M M M | M M M M M M M 12/08/2024 at 1400 MST | 12/08/2024 at 1700 MST | CAPE... 0.0 LI... +6.9 | CAPE... 0.0 LI... +6.8 CINH... 0.0 K Index... -9.8 | CINH... -0.3 K Index... -12.4 | 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 -61.6 -78.9 265 65 33 2.1 1.2 | -61.0 -77.8 265 66 34 1.6 0.9 45000 -58.4 -73.1 265 65 33 1.6 0.9 | -58.6 -73.5 265 68 35 1.5 0.8 40000 -60.2 -76.4 265 71 37 -1.2 -0.7 | -59.9 -75.8 270 73 37 -1.0 -0.5 38000 -58.7 -73.7 265 72 37 5.2 2.8 | -58.9 -74.0 270 73 38 4.4 2.4 36000 -55.6 -68.1 265 71 37 5.2 2.8 | -56.2 -69.2 270 71 37 4.4 2.4 34000 -52.1 -61.8 265 70 36 7.9 4.3 | -53.2 -63.8 270 70 36 8.2 4.5 32000 -47.4 -53.3 270 66 34 7.9 4.3 | -48.4 -55.1 270 68 35 8.0 4.4 30000 -42.8 -45.0 270 61 31 7.3 4.0 | -43.6 -46.5 270 66 34 7.6 4.2 29000 -40.6 -41.1 270 58 30 7.4 4.0 | -41.3 -42.3 270 64 33 7.6 4.2 28000 -38.3 -36.9 275 55 28 7.4 4.0 | -39.1 -38.4 270 62 32 7.6 4.2 27000 -36.1 -33.0 275 52 27 7.6 4.2 | -36.8 -34.2 270 60 31 7.7 4.2 26000 -33.7 -28.7 275 51 26 8.1 4.4 | -34.4 -29.9 270 61 31 7.9 4.3 25000 -31.3 -24.3 275 51 26 8.1 4.4 | -32.1 -25.8 270 61 31 7.9 4.3 24000 -28.3 -18.9 275 50 26 7.9 4.3 | -29.7 -21.5 270 61 32 7.9 4.4 23000 -25.9 -14.6 275 49 25 7.8 4.3 | -26.9 -16.4 270 61 31 7.5 4.1 22000 -23.6 -10.5 275 48 25 7.8 4.3 | -24.7 -12.5 270 60 31 7.5 4.1 21000 -21.2 -6.2 275 47 24 7.9 4.4 | -22.4 -8.3 275 59 30 7.2 4.0 20000 -18.8 -1.8 275 45 23 7.9 4.4 | -20.3 -4.5 275 56 29 7.2 3.9 19500 -17.7 0.1 280 45 23 7.9 4.4 | -19.2 -2.6 275 54 28 7.2 3.9 19000 -16.5 2.3 280 44 23 8.0 4.4 | -18.1 -0.6 275 53 27 7.2 3.9 18500 -15.3 4.5 280 44 23 7.5 4.1 | -17.1 1.2 280 51 26 7.2 3.9 18000 -14.2 6.4 280 43 22 7.4 4.1 | -16.0 3.2 280 49 25 7.2 3.9 17500 -13.1 8.4 280 42 22 7.3 4.0 | -14.9 5.2 280 47 24 7.2 3.9 17000 -12.1 10.2 280 41 21 6.4 3.5 | -13.8 7.2 280 45 23 6.9 3.8 16500 -11.1 12.0 280 39 20 6.5 3.6 | -12.8 9.0 280 44 23 7.0 3.8 16000 -10.2 13.6 280 38 20 5.3 2.9 | -11.8 10.8 280 42 22 6.3 3.5 15500 -9.4 15.1 280 37 19 5.3 2.9 | -10.9 12.4 280 40 21 6.2 3.4 15000 -8.6 16.5 280 35 18 4.8 2.6 | -9.9 14.2 280 38 20 5.6 3.1 14500 -8.0 17.6 285 34 17 4.5 2.5 | -9.2 15.4 280 36 19 5.1 2.8 14000 -7.3 18.9 285 32 17 4.5 2.5 | -8.4 16.9 280 34 17 5.1 2.8 13500 -6.7 19.9 285 31 16 4.4 2.4 | -7.7 18.1 280 32 16 5.0 2.7 13000 -6.0 21.2 285 29 15 4.5 2.5 | -7.0 19.4 280 30 15 5.0 2.8 12500 -5.4 22.3 285 27 14 4.5 2.5 | -6.2 20.8 280 28 14 4.9 2.7 12000 -4.8 23.4 285 25 13 4.6 2.5 | -5.5 22.1 280 26 13 5.0 2.7 11500 -4.1 24.6 285 23 12 5.4 3.0 | -4.8 23.4 280 24 12 5.5 3.0 11000 -3.3 26.1 285 21 11 5.2 2.9 | -4.0 24.8 275 22 11 5.4 3.0 10500 -2.7 27.1 280 19 10 4.2 2.3 | -3.3 26.1 275 20 10 4.3 2.4 10250 -2.3 27.9 280 18 9 4.0 2.2 | -3.0 26.6 270 19 10 3.8 2.1 10000 -2.0 28.4 280 17 9 5.1 2.8 | -2.7 27.1 270 18 9 6.2 3.4 9750 -1.6 29.1 275 15 8 5.0 2.7 | -2.2 28.0 265 17 9 6.8 3.7 9500 -1.3 29.7 270 14 7 3.8 2.1 | -1.8 28.8 265 16 8 4.6 2.5 9250 -1.0 30.2 270 13 7 4.1 2.3 | -1.5 29.3 260 15 8 5.5 3.0 9000 -0.7 30.7 265 12 6 4.0 2.2 | -1.1 30.0 255 14 7 4.1 2.2 8750 -0.4 31.3 260 12 6 3.7 2.1 | -0.9 30.4 255 14 7 3.8 2.1 8500 0.1 32.2 255 10 5 3.6 1.9 | -0.5 31.1 250 13 7 4.9 2.7 8250 0.3 32.5 255 9 5 2.1 1.1 | 0.2 32.4 250 11 5 4.5 2.5 8000 0.5 32.9 255 9 4 3.5 1.9 | 0.5 32.9 250 10 5 4.8 2.6 7750 0.9 33.6 255 7 4 5.7 3.1 | 0.9 33.6 250 9 5 5.1 2.8 7500 1.2 34.2 250 6 3 4.8 2.6 | 1.2 34.2 250 8 4 5.0 2.8 7250 1.5 34.7 255 5 3 3.2 1.7 | 1.6 34.9 255 7 3 5.0 2.7 7000 1.8 35.2 265 4 2 6.4 3.5 | 2.0 35.6 260 6 3 5.1 2.8 6750 2.5 36.5 265 3 2 9.8 5.4 | 2.3 36.1 260 5 2 5.4 3.0 6500 3.1 37.6 265 3 2 9.1 5.0 | 2.8 37.0 265 4 2 7.0 3.8 6250 3.9 39.0 275 3 1 10.0 5.5 | 3.4 38.1 275 3 2 8.4 4.6 6000 4.6 40.3 285 3 1 8.1 4.5 | 4.0 39.2 290 3 2 7.1 3.9 5750 5.1 41.2 270 3 1 8.8 4.8 | 4.2 39.6 280 2 1 -2.9 -1.6 5500 6.6 43.9 290 2 1 39.6 21.7 | 2.8 37.0 320 2 1 -42.9 -23.6 5250 M M M M M M M | M M M M M M M 5000 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) 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 at Walker Field in Grand Junction, Colorado at North Latitude: 39 deg 07 min 00.001 sec West Longitude: 108 deg 31 min 59.998 sec Elevation: 4839 feet (1475 meters) and may not be representative of other areas along the Western Slope of Colorado. 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