Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
563 UXUS97 KBOU 090024 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 1824 MDT Saturday, June 8, 2024 This forecast is for Sunday, June 9, 2024: If the trigger temperature of 77.4 F/25.2 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 642 ft/min (3.3 m/s) Maximum height of thermals.................. 11156 ft MSL (5849 ft AGL) Forecast maximum temperature................... 81.0 F/27.7 C Time of trigger temperature.................... 1200 MDT Time of overdevelopment........................ 1500 MDT Middle/high clouds during soaring window....... None Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 8542 ft MSL (3235 ft AGL) Thermal soaring outlook for Monday 06/10....... Good 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....................... 36506 ft MSL (31199 ft AGL) Wave soaring outlook for Monday 06/10.......... Poor Remarks... Sunrise/Sunset.................... 05:31:02 / 20:26:47 MDT Total possible sunshine........... 14 hr 55 min 45 sec (895 min 45 sec) Altitude of sun at 12:58:55 MDT... 73.25 degrees Upper air data from numerical model forecast valid on 06/09/2024 at 0600 MDT Freezing level.................. 14956 ft MSL (9649 ft AGL) Convective condensation level... 12527 ft MSL (7220 ft AGL) Lifted condensation level....... 12279 ft MSL (6972 ft AGL) Lifted index.................... -4.7 K index......................... +29.1 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 -58.1 -72.6 270 17 9 2.3 1.2 M M M M M 45000 -55.6 -68.1 260 23 12 -0.1 -0.1 M M M M M 40000 -55.0 -67.0 265 36 18 6.6 3.6 M M M M M 38000 -51.2 -60.2 275 34 17 6.4 3.5 M M M M M 36000 -47.4 -53.3 290 33 17 6.3 3.5 M M M M M 34000 -42.4 -44.3 290 33 17 8.8 4.8 M M M M M 32000 -37.2 -35.0 290 32 17 8.8 4.8 M M M M M 30000 -31.8 -25.2 295 32 17 9.1 5.0 44.7 112.5 13.3 M M 29000 -28.4 -19.1 295 33 17 9.1 5.0 44.4 112.0 13.3 M M 28000 -25.7 -14.3 295 33 17 7.4 4.1 44.3 111.7 13.3 M M 27000 -23.8 -10.8 295 31 16 6.2 3.4 42.8 109.0 12.3 M M 26000 -22.0 -7.6 295 30 15 6.2 3.4 41.4 106.6 11.4 M M 25000 -20.1 -4.2 295 29 15 6.2 3.4 40.2 104.4 10.5 M M 24000 -18.3 -0.9 300 28 14 6.3 3.5 38.9 102.0 9.5 M M 23000 -16.4 2.5 300 28 14 6.3 3.5 37.6 99.7 8.6 M M 22000 -14.5 5.9 300 27 14 6.4 3.5 36.5 97.6 7.7 M M 21000 -12.6 9.3 300 26 13 6.7 3.7 35.3 95.5 6.7 M M 20000 -10.6 12.9 305 24 13 6.7 3.7 34.2 93.6 5.8 M M 19500 -9.6 14.7 305 24 12 6.8 3.8 33.7 92.7 5.4 M M 19000 -8.7 16.3 305 23 12 5.2 2.9 33.2 91.7 4.9 M M 18500 -8.0 17.6 305 22 11 5.0 2.7 32.3 90.2 4.2 M M 18000 -7.3 18.9 305 20 10 5.4 3.0 31.5 88.7 3.4 M M 17500 -6.3 20.7 300 19 10 8.3 4.5 31.0 87.9 3.0 M M 17000 -5.2 22.6 300 17 9 8.2 4.5 30.8 87.4 2.6 M M 16500 -4.1 24.6 300 16 8 8.7 4.8 30.5 87.0 2.4 M M 16000 -2.8 27.0 300 14 7 8.7 4.8 30.4 86.6 2.1 M M 15500 -1.0 30.2 305 12 6 8.1 4.4 30.1 86.1 1.8 M M 15000 0.2 32.4 310 12 6 8.1 4.4 29.8 85.6 1.5 M M 14500 1.3 34.3 315 11 6 8.9 4.9 29.6 85.2 1.2 M M 14000 2.7 36.9 315 10 5 9.2 5.1 29.5 85.1 1.1 M M 13500 4.0 39.2 320 9 5 9.0 5.0 29.4 84.9 1.0 M M 13000 5.3 41.5 320 9 4 8.7 4.8 29.2 84.6 0.8 M M 12500 6.6 43.9 325 8 4 8.6 4.7 29.1 84.3 0.7 M M 12000 7.8 46.0 325 6 3 8.1 4.4 28.8 83.9 0.4 M M 11500 9.0 48.2 330 5 3 8.0 4.4 28.6 83.4 0.2 M M 11000 10.1 50.2 330 3 2 7.0 3.9 28.2 82.8 -0.2 423 2.2 10500 11.1 52.0 325 1 1 4.5 2.5 27.8 82.1 -0.6 377 1.9 10250 11.3 52.3 325 1 0 3.6 2.0 27.3 81.1 -1.1 364 1.8 10000 11.8 53.2 000 0 0 7.8 4.3 27.0 80.6 -1.4 343 1.7 9750 12.4 54.3 155 1 1 8.4 4.6 26.9 80.4 -1.6 319 1.6 9500 12.9 55.2 155 2 1 7.6 4.2 26.8 80.2 -1.7 294 1.5 9250 13.4 56.1 150 3 2 5.6 3.0 26.5 79.7 -2.0 273 1.4 9000 13.7 56.7 150 3 2 5.2 2.8 26.2 79.1 -2.4 255 1.3 8750 14.1 57.4 150 3 2 6.1 3.3 25.8 78.5 -2.7 236 1.2 8500 14.5 58.1 150 3 2 5.0 2.7 25.5 78.0 -3.1 217 1.1 8250 14.8 58.6 155 3 2 3.4 1.9 25.1 77.2 -3.5 202 1.0 8000 14.9 58.8 160 3 2 3.1 1.7 24.6 76.3 -4.1 190 1.0 7750 15.1 59.2 165 4 2 4.0 2.2 24.1 75.4 -4.6 176 0.9 7500 15.3 59.5 165 4 2 2.4 1.3 23.6 74.6 -5.2 163 0.8 7250 15.3 59.5 160 3 2 0.6 0.3 23.0 73.3 -5.9 156 0.8 7000 15.3 59.5 155 3 1 0.8 0.4 22.3 72.1 -6.7 150 0.8 6750 15.2 59.4 135 2 1 -0.5 -0.3 21.6 70.8 -7.5 145 0.7 6500 15.1 59.2 100 2 1 0.9 0.5 20.8 69.4 -8.4 140 0.7 6250 15.2 59.4 080 3 1 2.5 1.4 20.2 68.4 -9.0 129 0.7 6000 15.4 59.7 070 4 2 2.3 1.3 19.7 67.4 -9.6 118 0.6 5750 15.5 59.9 060 5 2 2.7 1.5 19.1 66.4 -10.2 106 0.5 5500 15.7 60.3 060 5 2 1.9 1.0 18.6 65.4 -10.8 95 0.5 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/09/2024 at 0900 MDT | 06/09/2024 at 1200 MDT | CAPE... +1195.7 LI... -3.7 | CAPE... +1704.2 LI... -4.5 CINH... -75.6 K Index... +26.0 | CINH... -26.1 K Index... +24.0 | 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 -58.1 -72.6 285 17 9 2.6 1.4 | -58.0 -72.4 295 17 9 2.4 1.3 45000 -55.5 -67.9 270 21 11 -1.0 -0.5 | -55.8 -68.4 275 20 10 -1.3 -0.7 40000 -56.1 -69.0 265 25 13 7.4 4.1 | -56.6 -69.9 260 19 10 7.9 4.3 38000 -51.8 -61.2 275 24 13 7.2 3.9 | -52.0 -61.6 275 17 8 7.7 4.3 36000 -47.5 -53.5 280 24 13 7.1 3.9 | -47.3 -53.1 290 15 8 7.7 4.2 34000 -42.5 -44.5 285 24 13 8.5 4.7 | -42.5 -44.5 295 17 9 8.2 4.5 32000 -37.4 -35.3 285 24 12 8.5 4.7 | -37.6 -35.7 300 19 10 8.2 4.5 30000 -31.7 -25.1 290 24 12 8.6 4.7 | -31.9 -25.4 300 21 11 8.5 4.6 29000 -29.1 -20.4 290 23 12 8.6 4.7 | -29.4 -20.9 295 21 11 8.5 4.6 28000 -26.5 -15.7 295 23 12 8.0 4.4 | -26.9 -16.4 295 22 11 8.2 4.5 27000 -24.2 -11.6 295 23 12 7.8 4.3 | -24.5 -12.1 295 22 11 8.1 4.4 26000 -21.9 -7.4 300 24 12 7.8 4.3 | -22.1 -7.8 300 23 12 8.1 4.4 25000 -19.6 -3.3 305 24 12 7.8 4.3 | -19.6 -3.3 300 23 12 8.0 4.4 24000 -17.7 0.1 305 24 12 6.2 3.4 | -17.6 0.3 305 22 11 6.6 3.6 23000 -15.8 3.6 310 24 12 6.2 3.4 | -15.6 3.9 310 21 11 6.7 3.7 22000 -14.0 6.8 310 24 12 6.3 3.4 | -13.7 7.3 310 19 10 6.6 3.6 21000 -12.1 10.2 315 23 12 6.6 3.6 | -11.7 10.9 310 18 9 6.5 3.6 20000 -10.2 13.6 315 22 11 6.6 3.6 | -9.8 14.4 310 16 8 6.6 3.6 19500 -9.2 15.4 315 21 11 6.7 3.7 | -8.8 16.2 310 15 8 6.6 3.6 19000 -8.3 17.1 315 21 11 5.5 3.0 | -7.9 17.8 305 15 8 5.8 3.2 18500 -7.5 18.5 315 19 10 5.3 2.9 | -7.1 19.2 305 14 7 5.8 3.2 18000 -6.8 19.8 315 18 9 5.4 3.0 | -6.2 20.8 305 13 7 6.0 3.3 17500 -5.9 21.4 315 17 9 6.2 3.4 | -5.4 22.3 300 12 6 6.3 3.4 17000 -5.1 22.8 315 16 8 6.1 3.4 | -4.5 23.9 300 11 6 6.2 3.4 16500 -3.5 25.7 310 14 7 8.6 4.7 | -3.5 25.7 300 10 5 7.6 4.2 16000 -2.3 27.9 310 13 7 8.5 4.7 | -1.9 28.6 295 9 5 7.6 4.2 15500 -1.1 30.0 310 11 6 8.9 4.9 | -0.7 30.7 295 8 4 8.9 4.9 15000 0.2 32.4 310 9 5 8.9 4.9 | 0.6 33.1 290 7 4 8.7 4.8 14500 1.5 34.7 310 8 4 8.7 4.8 | 1.8 35.2 285 7 3 9.1 5.0 14000 2.8 37.0 305 6 3 8.6 4.7 | 3.2 37.8 280 6 3 9.1 5.0 13500 4.0 39.2 300 5 2 8.5 4.7 | 4.5 40.1 270 5 2 8.9 4.9 13000 5.3 41.5 285 3 2 8.3 4.5 | 5.8 42.4 260 5 2 8.7 4.8 12500 6.5 43.7 255 3 1 8.0 4.4 | 7.0 44.6 245 5 2 8.4 4.6 12000 7.5 45.5 220 3 2 7.2 4.0 | 8.2 46.8 230 5 3 7.7 4.2 11500 8.6 47.5 195 4 2 7.2 4.0 | 9.3 48.7 220 6 3 7.4 4.1 11000 9.6 49.3 185 6 3 7.1 3.9 | 10.2 50.4 205 6 3 6.3 3.5 10500 10.6 51.1 175 7 4 4.0 2.2 | 11.1 52.0 195 7 4 3.5 1.9 10250 10.7 51.3 175 8 4 3.2 1.8 | 11.3 52.3 195 8 4 3.3 1.8 10000 11.2 52.2 170 9 4 8.7 4.8 | 11.7 53.1 190 8 4 7.6 4.2 9750 11.8 53.2 170 8 4 9.4 5.2 | 12.1 53.8 180 8 4 7.6 4.2 9500 12.4 54.3 170 8 4 8.3 4.6 | 12.6 54.7 175 8 4 6.3 3.5 9250 12.9 55.2 165 8 4 5.5 3.0 | 12.9 55.2 170 8 4 3.6 2.0 9000 13.2 55.8 160 8 4 5.7 3.1 | 13.1 55.6 165 8 4 4.6 2.5 8750 13.7 56.7 165 7 4 7.4 4.0 | 13.5 56.3 160 7 4 6.2 3.4 8500 14.2 57.6 165 6 3 5.6 3.1 | 13.8 56.8 150 7 4 4.8 2.6 8250 14.4 57.9 165 6 3 4.2 2.3 | 14.0 57.2 140 6 3 2.9 1.6 8000 14.7 58.5 165 5 3 1.9 1.0 | 14.2 57.6 125 5 2 4.5 2.4 7750 14.5 58.1 160 4 2 -2.9 -1.6 | 14.5 58.1 110 5 2 6.6 3.6 7500 14.2 57.6 150 3 1 -0.6 -0.4 | 14.9 58.8 105 5 3 7.5 4.1 7250 14.3 57.7 130 2 1 2.8 1.5 | 15.5 59.9 095 5 3 7.6 4.2 7000 14.5 58.1 110 2 1 1.8 1.0 | 16.1 61.0 090 5 2 8.7 4.8 6750 14.5 58.1 100 3 1 2.4 1.3 | 16.8 62.2 085 5 3 12.5 6.8 6500 14.6 58.3 100 3 2 4.9 2.7 | 17.8 64.0 090 5 3 11.9 6.5 6250 15.0 59.0 085 3 2 6.4 3.5 | 18.6 65.5 085 5 2 10.5 5.8 6000 15.5 59.9 070 3 2 6.0 3.3 | 19.3 66.7 075 4 2 9.3 5.1 5750 16.0 60.8 065 3 2 12.1 6.6 | 20.1 68.2 085 5 2 16.2 8.9 5500 17.2 63.0 065 3 2 20.7 11.4 | 21.9 71.4 075 4 2 33.1 18.1 06/09/2024 at 1500 MDT | 06/09/2024 at 1800 MDT | CAPE... +2177.2 LI... -5.0 | CAPE... +1972.6 LI... -5.0 CINH... -0.0 K Index... +29.8 | CINH... -1.3 K Index... +33.9 | 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 -58.1 -72.6 280 13 7 2.5 1.4 | -57.5 -71.5 285 13 7 2.9 1.6 45000 -55.8 -68.4 260 21 11 -1.2 -0.6 | -54.9 -66.8 265 22 11 -1.4 -0.8 40000 -56.3 -69.3 245 26 13 7.6 4.2 | -55.8 -68.4 250 40 21 7.9 4.3 38000 -51.8 -61.2 245 17 9 7.6 4.1 | -51.1 -60.0 250 33 17 7.9 4.3 36000 -47.3 -53.1 250 9 4 7.5 4.1 | -46.3 -51.3 250 26 13 7.9 4.3 34000 -42.3 -44.1 270 8 4 8.4 4.6 | -41.5 -42.7 260 20 10 8.0 4.4 32000 -37.3 -35.1 285 11 6 8.4 4.6 | -36.7 -34.1 280 16 8 7.9 4.4 30000 -31.6 -24.9 285 15 7 8.4 4.6 | -31.0 -23.8 295 16 8 8.6 4.7 29000 -29.1 -20.4 285 16 8 8.4 4.6 | -28.5 -19.3 295 16 8 8.6 4.7 28000 -26.7 -16.1 290 18 9 7.8 4.3 | -25.9 -14.6 300 16 8 7.4 4.1 27000 -24.3 -11.7 295 18 9 7.7 4.2 | -23.8 -10.8 310 16 8 7.1 3.9 26000 -22.0 -7.6 300 19 10 7.7 4.2 | -21.7 -7.1 320 16 8 7.1 3.9 25000 -19.7 -3.5 305 20 10 7.7 4.2 | -19.6 -3.3 325 17 9 7.1 3.9 24000 -17.4 0.7 310 20 10 7.7 4.2 | -17.4 0.7 330 17 9 7.3 4.0 23000 -15.1 4.8 310 19 10 7.7 4.2 | -15.3 4.5 335 16 8 7.3 4.0 22000 -12.8 9.0 315 19 10 7.4 4.1 | -13.1 8.4 340 15 8 7.2 4.0 21000 -10.8 12.6 310 17 9 6.7 3.7 | -11.0 12.2 335 14 7 6.9 3.8 20000 -8.8 16.2 305 15 8 6.7 3.7 | -8.9 16.0 335 13 7 6.9 3.8 19500 -7.8 18.0 305 14 7 6.6 3.6 | -7.9 17.8 330 12 6 6.8 3.7 19000 -6.8 19.8 300 14 7 7.3 4.0 | -6.8 19.8 330 12 6 7.5 4.1 18500 -5.8 21.6 300 14 7 7.3 4.0 | -5.8 21.6 325 12 6 7.7 4.2 18000 -4.7 23.5 295 15 8 7.5 4.1 | -4.7 23.5 325 13 6 7.5 4.1 17500 -3.6 25.5 295 15 8 7.8 4.3 | -3.8 25.2 325 12 6 6.6 3.6 17000 -2.6 27.3 295 15 8 8.1 4.4 | -2.9 26.8 325 12 6 6.9 3.8 16500 -1.6 29.1 295 14 7 6.1 3.4 | -2.1 28.2 320 10 5 5.6 3.1 16000 -0.8 30.6 295 13 7 6.3 3.5 | -1.3 29.7 310 7 4 5.7 3.1 15500 0.1 32.2 295 12 6 6.2 3.4 | -0.5 31.1 290 4 2 6.1 3.3 15000 1.4 34.5 290 8 4 5.9 3.2 | 0.4 32.7 230 3 2 6.3 3.5 14500 2.4 36.3 280 5 3 7.4 4.0 | 1.9 35.4 185 7 4 6.7 3.7 14000 3.5 38.3 250 4 2 7.6 4.2 | 2.9 37.2 185 9 5 6.8 3.8 13500 4.6 40.3 210 4 2 8.0 4.4 | 3.8 38.8 185 11 6 7.7 4.2 13000 5.8 42.4 195 4 2 8.2 4.5 | 4.9 40.8 185 11 6 8.3 4.6 12500 7.0 44.6 185 5 3 7.4 4.1 | 6.0 42.8 185 12 6 8.6 4.7 12000 7.9 46.2 180 7 3 6.1 3.4 | 7.1 44.8 185 11 6 8.8 4.8 11500 8.7 47.7 180 8 4 6.2 3.4 | 8.2 46.8 180 11 6 8.7 4.8 11000 9.4 48.9 175 9 5 6.2 3.4 | 9.4 48.9 175 11 6 8.0 4.4 10500 10.2 50.4 170 10 5 1.9 1.0 | 10.6 51.1 165 11 6 3.0 1.7 10250 10.1 50.2 170 10 5 3.5 1.9 | 10.6 51.1 165 11 6 4.7 2.6 10000 10.7 51.3 160 9 5 10.9 6.0 | 11.4 52.5 165 11 6 12.5 6.9 9750 11.3 52.3 145 9 4 9.3 5.1 | 12.2 54.0 160 11 6 11.0 6.0 9500 11.9 53.4 130 9 5 9.0 4.9 | 13.0 55.4 160 11 6 9.3 5.1 9250 12.5 54.5 125 9 5 8.0 4.4 | 13.6 56.5 160 12 6 6.8 3.7 9000 13.1 55.6 120 9 5 10.0 5.5 | 14.2 57.6 160 12 6 9.9 5.4 8750 13.9 57.0 120 9 5 11.4 6.3 | 15.0 59.0 160 12 6 11.9 6.5 8500 14.8 58.6 115 9 5 10.3 5.7 | 15.9 60.6 160 12 6 10.2 5.6 8250 15.5 59.9 115 9 5 9.5 5.2 | 16.6 61.9 160 12 6 8.7 4.8 8000 16.2 61.2 115 9 5 9.8 5.4 | 17.2 63.0 160 12 6 9.8 5.4 7750 17.0 62.6 115 9 5 10.0 5.5 | 18.0 64.4 160 12 6 10.8 5.9 7500 17.7 63.9 110 9 5 10.4 5.7 | 18.8 65.8 160 12 6 10.1 5.5 7250 18.5 65.3 110 9 4 10.7 5.9 | 19.5 67.1 155 12 6 9.5 5.2 7000 19.3 66.7 110 9 4 10.4 5.7 | 20.2 68.4 155 11 6 9.9 5.5 6750 20.0 68.0 110 9 4 10.2 5.6 | 21.0 69.8 155 11 6 10.4 5.7 6500 20.8 69.4 105 8 4 10.4 5.7 | 21.8 71.2 155 11 6 10.0 5.5 6250 21.6 70.9 105 8 4 11.8 6.5 | 22.5 72.5 155 11 6 9.7 5.3 6000 22.4 72.3 105 8 4 7.8 4.3 | 23.2 73.8 155 11 5 9.6 5.3 5750 23.0 73.4 105 8 4 14.5 7.9 | 24.0 75.2 155 11 5 11.4 6.2 5500 24.9 76.8 100 8 4 36.9 20.2 | 24.9 76.8 155 10 5 14.6 8.0 ________________________________________________________________________________ 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