Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
371 UXUS97 KBOU 130118 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 1918 MDT Wednesday, June 12, 2024 This forecast is for Thursday, June 13, 2024: If the trigger temperature of 87.4 F/30.8 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1568 ft/min (8.0 m/s) Maximum height of thermals.................. 21218 ft MSL (15929 ft AGL) Forecast maximum temperature................... 96.0 F/36.0 C Time of trigger temperature.................... 1030 MDT Time of overdevelopment........................ 1600 MDT Middle/high clouds during soaring window....... None Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 13604 ft MSL (8315 ft AGL) Thermal soaring outlook for Friday 06/14....... 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)................ Neither Potential height of wave....................... 40981 ft MSL (35692 ft AGL) Wave soaring outlook for Friday 06/14.......... Poor Remarks... Hot again on Thursday Sunrise/Sunset.................... 05:30:48 / 20:28:41 MDT Total possible sunshine........... 14 hr 57 min 53 sec (897 min 53 sec) Altitude of sun at 12:59:44 MDT... 73.50 degrees Upper air data from numerical model forecast valid on 06/13/2024 at 0600 MDT Freezing level.................. 16373 ft MSL (11084 ft AGL) Convective condensation level... 18210 ft MSL (12921 ft AGL) Lifted condensation level....... 19039 ft MSL (13750 ft AGL) Lifted index.................... -3.9 K index......................... +23.0 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 -61.4 -78.5 275 38 20 2.3 1.3 M M M M M 45000 -57.2 -71.0 275 44 23 3.5 1.9 M M M M M 40000 -51.6 -60.9 275 51 26 5.5 3.0 M M M M M 38000 -48.2 -54.8 280 49 25 5.6 3.0 M M M M M 36000 -44.9 -48.8 280 47 24 5.4 3.0 M M M M M 34000 -40.8 -41.4 280 46 24 7.1 3.9 M M M M M 32000 -36.6 -33.9 280 45 23 7.0 3.9 M M M M M 30000 -32.3 -26.1 275 37 19 6.2 3.4 42.7 108.8 5.4 M M 29000 -30.4 -22.7 270 32 17 6.2 3.4 41.3 106.4 4.5 M M 28000 -28.5 -19.3 265 29 15 7.5 4.1 40.2 104.3 3.6 M M 27000 -26.2 -15.2 270 28 15 7.6 4.2 39.3 102.7 2.9 M M 26000 -23.9 -11.0 275 28 14 7.6 4.2 38.5 101.2 2.3 M M 25000 -21.6 -6.9 280 27 14 7.9 4.3 37.8 100.0 1.8 M M 24000 -19.1 -2.4 280 28 14 8.4 4.6 37.2 98.9 1.3 M M 23000 -16.6 2.1 285 29 15 8.4 4.6 36.7 98.1 0.9 M M 22000 -14.1 6.6 290 30 15 8.2 4.5 36.3 97.4 0.5 M M 21000 -11.8 10.8 285 30 16 8.0 4.4 35.6 96.1 -0.1 1550 7.9 20000 -9.4 15.1 285 31 16 8.1 4.4 35.0 95.1 -0.6 1449 7.4 19500 -8.2 17.2 285 31 16 8.1 4.4 34.8 94.6 -0.9 1399 7.1 19000 -7.0 19.4 285 30 16 8.4 4.6 34.5 94.2 -1.2 1349 6.9 18500 -5.8 21.6 285 30 15 8.6 4.7 34.3 93.8 -1.5 1298 6.6 18000 -4.6 23.7 280 29 15 8.9 4.9 34.1 93.4 -1.7 1248 6.3 17500 -3.3 26.1 285 28 14 9.1 5.0 34.0 93.2 -1.9 1192 6.1 17000 -1.9 28.6 285 27 14 9.1 5.0 33.9 93.0 -2.0 1137 5.8 16500 -0.6 30.9 285 26 13 8.8 4.8 33.7 92.7 -2.1 1083 5.5 16000 0.7 33.3 285 24 13 8.8 4.8 33.6 92.4 -2.3 1030 5.2 15500 2.6 36.7 285 23 12 9.2 5.0 33.4 92.1 -2.6 948 4.8 15000 4.0 39.2 285 21 11 9.2 5.0 33.3 91.9 -2.7 893 4.5 14500 5.3 41.5 290 20 10 9.2 5.0 33.2 91.7 -2.8 838 4.3 14000 6.7 44.1 290 19 10 9.2 5.0 33.1 91.6 -2.9 782 4.0 13500 8.0 46.4 290 18 9 8.9 4.9 33.0 91.4 -3.1 727 3.7 13000 9.3 48.7 290 17 9 8.8 4.8 32.8 91.1 -3.2 673 3.4 12500 10.6 51.1 290 16 8 9.1 5.0 32.7 90.8 -3.4 620 3.1 12000 12.0 53.6 290 15 8 9.3 5.1 32.6 90.7 -3.5 564 2.9 11500 13.4 56.1 285 14 7 9.0 5.0 32.6 90.6 -3.6 507 2.6 11000 14.7 58.5 285 13 7 8.4 4.6 32.4 90.3 -3.8 454 2.3 10500 15.9 60.6 285 11 6 4.9 2.7 32.2 90.0 -4.0 402 2.0 10250 16.1 61.0 285 11 6 6.0 3.3 31.7 89.0 -4.5 388 2.0 10000 16.9 62.4 285 11 5 11.4 6.3 31.7 89.1 -4.5 357 1.8 9750 17.7 63.9 280 10 5 10.5 5.7 31.8 89.2 -4.5 327 1.7 9500 18.4 65.1 280 9 5 8.8 4.9 31.8 89.3 -4.5 297 1.5 9250 19.0 66.2 280 9 4 7.1 3.9 31.6 89.0 -4.7 273 1.4 9000 19.6 67.3 280 8 4 9.0 4.9 31.5 88.7 -4.8 247 1.3 8750 20.3 68.5 280 7 4 9.6 5.3 31.5 88.7 -4.8 219 1.1 8500 21.0 69.8 280 7 3 9.3 5.1 31.5 88.7 -4.9 190 1.0 8250 21.7 71.1 280 7 3 9.2 5.0 31.4 88.6 -4.9 162 0.8 8000 22.4 72.3 280 6 3 9.2 5.0 31.4 88.5 -5.0 134 0.7 7750 23.1 73.6 285 6 3 9.3 5.1 31.3 88.4 -5.0 106 0.5 7500 23.7 74.7 285 6 3 8.0 4.4 31.3 88.3 -5.1 79 0.4 7250 24.2 75.6 280 6 3 6.9 3.8 31.1 88.0 -5.3 56 0.3 7000 24.8 76.6 280 6 3 7.7 4.2 30.9 87.6 -5.6 33 0.2 6750 25.3 77.5 275 6 3 4.7 2.6 30.7 87.2 -5.8 11 0.1 6500 25.3 77.5 270 6 3 -1.9 -1.1 30.0 86.1 -6.5 1 0.0 6250 25.0 77.0 260 6 3 -7.5 -4.1 28.9 84.1 -7.6 5 0.0 6000 24.6 76.3 250 6 3 3.1 1.7 27.8 82.1 -8.7 8 0.0 5750 24.8 76.6 245 7 3 -9.8 -5.4 27.3 81.2 -9.2 M M 5500 22.0 71.6 230 6 3 -66.0 -36.2 23.8 74.9 -12.8 73 0.4 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/13/2024 at 0900 MDT | 06/13/2024 at 1200 MDT | CAPE... +180.9 LI... +0.2 | CAPE... +393.8 LI... -0.6 CINH... -177.0 K Index... +20.0 | CINH... -17.9 K Index... +16.8 | 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 -60.6 -77.1 280 39 20 2.3 1.3 | -60.9 -77.6 280 42 21 2.3 1.2 45000 -56.7 -70.1 275 52 27 3.1 1.7 | -57.1 -70.8 280 61 31 3.0 1.7 40000 -51.7 -61.1 280 60 31 5.5 3.0 | -52.1 -61.8 280 70 36 5.9 3.2 38000 -48.3 -54.9 280 53 27 5.6 3.1 | -48.5 -55.3 280 61 31 5.9 3.3 36000 -44.9 -48.8 280 46 24 5.5 3.0 | -44.9 -48.8 280 52 27 5.9 3.2 34000 -41.0 -41.8 275 42 22 6.6 3.6 | -40.6 -41.1 280 44 23 6.4 3.5 32000 -36.6 -33.9 275 39 20 6.8 3.7 | -36.7 -34.1 275 37 19 6.6 3.6 30000 -32.2 -26.0 275 36 19 7.3 4.0 | -32.3 -26.1 275 33 17 7.4 4.1 29000 -30.0 -22.0 280 35 18 7.3 4.0 | -30.1 -22.2 275 31 16 7.4 4.1 28000 -27.9 -18.2 280 34 18 6.9 3.8 | -27.9 -18.2 275 29 15 7.0 3.8 27000 -25.8 -14.4 280 33 17 6.9 3.8 | -25.8 -14.4 275 29 15 7.0 3.8 26000 -23.7 -10.7 280 32 16 6.9 3.8 | -23.7 -10.7 275 30 15 7.0 3.9 25000 -21.6 -6.9 275 30 16 7.6 4.2 | -21.6 -6.9 275 30 15 7.7 4.2 24000 -19.1 -2.4 280 29 15 8.6 4.7 | -19.0 -2.2 275 28 14 8.6 4.7 23000 -16.5 2.3 280 29 15 8.6 4.7 | -16.5 2.3 275 26 13 8.6 4.7 22000 -13.9 7.0 285 28 14 8.1 4.5 | -13.9 7.0 275 24 13 8.3 4.5 21000 -11.6 11.1 285 27 14 7.7 4.2 | -11.5 11.3 275 24 13 8.1 4.5 20000 -9.3 15.3 285 27 14 7.8 4.3 | -9.1 15.6 275 24 13 8.1 4.5 19500 -8.2 17.2 285 27 14 7.8 4.3 | -7.9 17.8 275 24 13 8.0 4.4 19000 -7.0 19.4 285 26 14 8.2 4.5 | -6.8 19.8 275 24 12 7.4 4.1 18500 -5.9 21.4 285 26 13 8.3 4.5 | -5.8 21.6 275 24 12 7.6 4.2 18000 -4.7 23.5 280 25 13 9.3 5.1 | -4.6 23.7 275 23 12 9.1 5.0 17500 -3.3 26.1 280 25 13 9.7 5.3 | -3.2 26.2 275 22 11 9.5 5.2 17000 -1.8 28.8 280 24 12 9.7 5.3 | -1.8 28.8 275 21 11 9.5 5.2 16500 -0.5 31.1 285 23 12 8.7 4.8 | -0.4 31.3 280 20 11 9.2 5.1 16000 0.9 33.6 285 22 11 8.8 4.8 | 1.7 35.1 280 19 10 9.2 5.1 15500 2.8 37.0 280 20 10 8.9 4.9 | 3.1 37.6 280 18 9 9.3 5.1 15000 4.1 39.4 280 19 10 8.9 4.9 | 4.4 39.9 275 17 9 9.3 5.1 14500 5.4 41.7 280 17 9 9.4 5.2 | 5.8 42.4 275 15 8 8.8 4.8 14000 6.8 44.2 280 16 8 9.4 5.2 | 7.0 44.6 275 13 7 8.8 4.8 13500 8.2 46.8 280 14 7 8.9 4.9 | 8.3 46.9 270 12 6 9.6 5.3 13000 9.5 49.1 280 13 7 8.8 4.8 | 9.8 49.6 270 10 5 9.6 5.3 12500 10.8 51.4 275 12 6 9.1 5.0 | 11.2 52.2 265 9 5 9.6 5.2 12000 12.2 54.0 275 11 6 9.2 5.0 | 12.6 54.7 265 8 4 9.5 5.2 11500 13.5 56.3 270 10 5 8.9 4.9 | 14.0 57.2 260 7 4 9.0 4.9 11000 14.8 58.6 265 9 5 8.4 4.6 | 15.3 59.5 255 6 3 8.5 4.7 10500 16.1 61.0 260 8 4 4.7 2.6 | 16.6 61.9 245 6 3 4.0 2.2 10250 16.3 61.3 260 8 4 6.2 3.4 | 16.8 62.2 240 5 3 6.0 3.3 10000 17.1 62.8 255 7 4 11.9 6.5 | 17.5 63.5 235 4 2 12.0 6.6 9750 17.9 64.2 255 7 4 11.3 6.2 | 18.3 64.9 215 3 1 10.9 6.0 9500 18.7 65.7 250 6 3 8.3 4.5 | 19.0 66.2 185 2 1 8.3 4.6 9250 19.1 66.4 245 6 3 5.8 3.2 | 19.5 67.1 170 2 1 7.1 3.9 9000 19.7 67.5 245 6 3 9.1 5.0 | 20.1 68.2 160 2 1 10.4 5.7 8750 20.4 68.7 240 5 3 9.9 5.4 | 20.9 69.6 150 2 1 10.8 5.9 8500 21.1 70.0 240 5 2 8.8 4.8 | 21.7 71.1 140 2 1 10.1 5.6 8250 21.7 71.1 235 4 2 7.9 4.3 | 22.4 72.3 135 2 1 9.6 5.3 8000 22.3 72.1 230 4 2 8.7 4.8 | 23.2 73.8 130 2 1 10.2 5.6 7750 23.0 73.4 225 4 2 9.1 5.0 | 23.9 75.0 125 2 1 10.5 5.8 7500 23.6 74.5 220 4 2 7.6 4.1 | 24.7 76.5 120 2 1 10.1 5.6 7250 24.1 75.4 215 4 2 6.4 3.5 | 25.5 77.9 115 2 1 9.9 5.4 7000 24.6 76.3 210 4 2 7.7 4.2 | 26.2 79.2 110 2 1 10.4 5.7 6750 25.2 77.4 200 4 2 7.1 3.9 | 27.0 80.6 110 2 1 10.8 5.9 6500 25.6 78.1 200 4 2 2.9 1.6 | 27.8 82.0 105 2 1 10.4 5.7 6250 25.7 78.3 200 4 2 3.1 1.7 | 28.6 83.5 100 2 1 10.4 5.7 6000 25.9 78.6 195 4 2 -1.6 -0.9 | 29.3 84.7 095 1 1 9.8 5.4 5750 25.7 78.3 205 4 2 2.3 1.3 | 30.2 86.4 090 2 1 16.0 8.8 5500 26.6 79.9 200 3 2 23.8 13.1 | 31.9 89.4 085 2 1 27.9 15.3 06/13/2024 at 1500 MDT | 06/13/2024 at 1800 MDT | CAPE... +411.5 LI... -0.6 | CAPE... +399.9 LI... -1.3 CINH... -22.6 K Index... +22.4 | CINH... -18.3 K Index... +23.5 | 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 -61.0 -77.8 275 44 23 2.2 1.2 | -61.7 -79.1 265 42 22 3.1 1.7 45000 -57.1 -70.8 275 67 35 3.5 1.9 | -56.9 -70.4 270 61 31 3.5 1.9 40000 -51.0 -59.8 275 71 37 5.9 3.3 | -50.8 -59.4 270 63 33 5.9 3.2 38000 -47.5 -53.5 275 63 32 5.9 3.2 | -47.3 -53.1 270 58 30 5.8 3.2 36000 -43.9 -47.0 275 54 28 6.0 3.3 | -43.8 -46.8 270 52 27 6.0 3.3 34000 -40.1 -40.2 275 47 24 6.4 3.5 | -39.8 -39.6 270 47 24 6.7 3.7 32000 -36.2 -33.2 275 41 21 6.4 3.5 | -35.8 -32.4 265 43 22 6.7 3.7 30000 -32.1 -25.8 275 35 18 7.0 3.8 | -31.6 -24.9 265 36 18 7.0 3.8 29000 -30.0 -22.0 275 33 17 7.0 3.8 | -29.5 -21.1 265 32 16 7.0 3.8 28000 -27.4 -17.3 275 30 16 7.1 3.9 | -27.0 -16.6 265 28 15 7.0 3.8 27000 -25.3 -13.5 275 30 15 7.1 3.9 | -24.9 -12.8 260 28 15 7.0 3.9 26000 -23.2 -9.8 275 30 15 7.1 3.9 | -22.8 -9.0 260 28 15 7.1 3.9 25000 -21.1 -6.0 275 30 15 7.5 4.1 | -20.7 -5.3 260 28 15 8.0 4.4 24000 -18.8 -1.8 270 29 15 7.7 4.2 | -18.3 -0.9 260 26 13 8.4 4.6 23000 -16.5 2.3 265 28 14 7.8 4.3 | -15.8 3.6 260 24 12 8.4 4.6 22000 -14.2 6.4 260 27 14 9.2 5.0 | -13.4 7.9 260 22 11 8.0 4.4 21000 -11.5 11.3 265 25 13 9.4 5.2 | -11.1 12.0 260 19 10 8.0 4.4 20000 -8.7 16.3 265 23 12 9.5 5.2 | -8.7 16.3 265 17 9 8.0 4.4 19500 -7.4 18.7 265 22 11 9.4 5.1 | -7.6 18.3 270 16 8 8.4 4.6 19000 -6.0 21.2 265 21 11 8.9 4.9 | -6.2 20.8 270 15 8 9.2 5.0 18500 -4.7 23.5 265 20 10 9.0 4.9 | -4.9 23.2 270 14 7 9.1 5.0 18000 -3.4 25.9 265 18 9 8.5 4.7 | -3.5 25.7 270 13 7 9.6 5.2 17500 -2.2 28.0 265 17 9 8.5 4.7 | -2.1 28.2 270 12 6 9.6 5.3 17000 -0.9 30.4 265 17 9 8.8 4.8 | -0.6 30.9 270 11 6 9.5 5.2 16500 0.5 32.9 265 15 8 9.7 5.3 | 0.8 33.4 265 9 5 9.3 5.1 16000 1.9 35.4 260 14 7 9.8 5.4 | 2.1 35.8 265 7 4 9.4 5.1 15500 3.3 37.9 260 13 7 9.0 4.9 | 3.5 38.3 255 5 2 8.9 4.9 15000 4.7 40.5 260 11 6 9.0 4.9 | 4.8 40.6 245 3 2 8.9 4.9 14500 6.0 42.8 255 9 5 9.0 4.9 | 6.1 43.0 210 2 1 9.3 5.1 14000 8.0 46.4 245 7 3 8.9 4.9 | 8.2 46.8 135 1 1 9.5 5.2 13500 9.4 48.9 240 5 3 9.1 5.0 | 9.6 49.3 105 2 1 9.3 5.1 13000 10.7 51.3 225 3 2 9.1 5.0 | 10.9 51.6 090 2 1 9.3 5.1 12500 12.0 53.6 205 2 1 9.3 5.1 | 12.3 54.1 085 3 1 9.5 5.2 12000 13.4 56.1 185 2 1 9.4 5.1 | 13.7 56.7 080 3 1 9.5 5.2 11500 14.7 58.5 165 2 1 9.1 5.0 | 15.1 59.2 075 3 1 9.4 5.2 11000 16.1 61.0 155 1 1 8.9 4.9 | 16.5 61.7 070 3 1 9.3 5.1 10500 17.3 63.1 150 1 1 6.1 3.4 | 17.8 64.0 065 3 2 5.4 2.9 10250 17.7 63.9 145 1 1 8.9 4.9 | 18.2 64.8 065 3 2 7.3 4.0 10000 18.6 65.5 145 1 1 12.6 6.9 | 19.0 66.2 060 3 2 12.5 6.9 9750 19.5 67.1 140 1 1 12.2 6.7 | 19.9 67.8 060 3 2 11.6 6.4 9500 20.3 68.5 140 1 1 8.9 4.9 | 20.7 69.3 060 3 2 9.6 5.3 9250 20.9 69.6 135 1 1 7.8 4.3 | 21.3 70.3 055 3 2 8.7 4.8 9000 21.6 70.9 135 1 0 11.1 6.1 | 22.1 71.8 055 3 2 11.0 6.0 8750 22.4 72.3 130 1 0 11.1 6.1 | 22.9 73.2 055 3 2 11.0 6.1 8500 23.2 73.8 125 1 0 10.2 5.6 | 23.7 74.7 050 3 2 9.8 5.4 8250 24.0 75.2 125 1 0 9.4 5.2 | 24.3 75.7 050 3 2 8.5 4.6 8000 24.7 76.5 120 1 0 9.9 5.4 | 25.0 77.0 050 3 2 10.1 5.6 7750 25.4 77.7 115 1 0 10.1 5.5 | 25.8 78.4 050 3 2 11.2 6.1 7500 26.2 79.2 110 1 0 10.2 5.6 | 26.6 79.9 045 3 2 10.1 5.6 7250 26.9 80.4 105 1 0 10.3 5.7 | 27.4 81.3 045 3 2 9.7 5.3 7000 27.7 81.9 100 1 0 10.3 5.6 | 28.1 82.6 045 3 2 9.8 5.4 6750 28.5 83.3 000 0 0 10.3 5.6 | 28.8 83.8 045 3 2 10.0 5.5 6500 29.3 84.7 000 0 0 10.2 5.6 | 29.6 85.3 040 3 2 10.2 5.6 6250 30.0 86.0 000 0 0 10.5 5.7 | 30.3 86.5 040 3 2 10.5 5.8 6000 30.8 87.4 000 0 0 9.4 5.1 | 31.1 88.0 040 3 2 9.3 5.1 5750 31.6 88.9 000 0 0 15.9 8.7 | 31.8 89.2 040 3 2 11.3 6.2 5500 33.3 91.9 050 1 0 30.0 16.5 | 32.9 91.2 040 3 2 18.5 10.2 ________________________________________________________________________________ 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