Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
265 UXUS97 KPUB 121213 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0613 MDT Monday, August 12, 2024 This forecast is for the Air Force Academy for Monday, August 12, 2024: If the trigger temperature of 72.8 F/22.7 C is reached...then Thermal Soaring Index....................... Poor Maximum rate of lift........................ 149 ft/min (0.8 m/s) Maximum height of thermals.................. 13578 ft MSL (5985 ft AGL) Forecast maximum temperature................... 75.0 F/24.3 C Time of trigger temperature.................... 1045 MDT Time of overdevelopment........................ None Middle/high clouds during soaring window....... Broken/overcast opaque middle Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 9430 ft MSL (1838 ft AGL) Thermal soaring outlook for Tuesday 08/13...... Good Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:10:50 / 19:57:33 MDT Total possible sunshine........... 13 hr 46 min 43 sec (826 min 43 sec) Altitude of sun at 13:04:12 MDT... 65.64 degrees Upper air data from numerical model forecast valid on 08/12/2024 at 0600 MDT Freezing level.................. 16602 ft MSL (9009 ft AGL) Convective condensation level... 15165 ft MSL (7572 ft AGL) Lifted condensation level....... 14632 ft MSL (7040 ft AGL) Lifted index.................... -2.8 K index......................... +21.4 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 -65.0 -85.0 275 23 12 1.9 1.0 M M M M M 45000 -59.5 -75.1 270 33 17 6.8 3.7 M M M M M 40000 -49.3 -56.7 265 35 18 6.7 3.7 M M M M M 38000 -44.8 -48.6 265 39 20 6.7 3.7 M M M M M 36000 -40.7 -41.3 265 42 22 7.0 3.8 M M M M M 34000 -36.4 -33.5 265 39 20 7.2 3.9 M M M M M 32000 -32.1 -25.8 265 35 18 7.6 4.2 M M M M M 30000 -28.3 -18.9 260 28 14 6.4 3.5 40.7 105.3 13.0 M M 29000 -26.4 -15.5 260 24 12 6.5 3.5 39.5 103.1 12.2 M M 28000 -24.5 -12.1 255 21 11 7.0 3.8 38.4 101.1 11.4 M M 27000 -22.4 -8.3 265 20 10 7.0 3.8 37.3 99.1 10.6 M M 26000 -20.3 -4.5 275 19 10 7.0 3.9 36.3 97.3 9.9 M M 25000 -18.3 -0.9 285 19 10 7.0 3.9 35.4 95.7 9.2 M M 24000 -16.2 2.8 275 16 8 7.0 3.9 34.3 93.7 8.4 M M 23000 -14.1 6.6 265 14 7 7.0 3.9 33.3 92.0 7.6 M M 22000 -11.6 11.1 250 11 6 6.2 3.4 32.2 89.9 6.7 M M 21000 -9.7 14.5 260 7 4 6.2 3.4 30.8 87.5 5.6 M M 20000 -7.8 18.0 290 4 2 6.3 3.4 29.7 85.4 4.7 M M 19500 -6.8 19.8 320 4 2 7.3 4.0 29.1 84.4 4.3 M M 19000 -5.6 21.9 325 4 2 8.6 4.7 28.9 84.0 4.1 M M 18500 -4.3 24.3 330 4 2 8.7 4.8 28.7 83.7 3.9 M M 18000 -3.1 26.4 325 3 2 8.3 4.6 28.5 83.3 3.7 M M 17500 -1.9 28.6 285 3 2 8.3 4.5 28.2 82.8 3.5 M M 17000 -0.7 30.7 255 4 2 7.6 4.2 28.0 82.5 3.2 M M 16500 0.3 32.5 245 5 3 6.6 3.6 27.5 81.5 2.7 M M 16000 1.2 34.2 235 7 4 6.6 3.6 27.0 80.6 2.2 M M 15500 2.1 35.8 235 8 4 6.8 3.8 26.5 79.7 1.6 M M 15000 3.0 37.4 230 9 5 6.8 3.8 26.0 78.8 1.1 M M 14500 4.0 39.2 230 10 5 7.6 4.2 25.6 78.0 0.7 M M 14000 5.1 41.2 225 10 5 7.7 4.2 25.3 77.5 0.3 M M 13500 6.2 43.2 225 10 5 7.6 4.2 24.9 76.9 -0.1 542 2.8 13000 7.3 45.1 225 10 5 7.7 4.2 24.6 76.2 -0.4 495 2.5 12500 8.6 47.5 225 10 5 9.0 4.9 24.4 75.9 -0.6 443 2.2 12000 9.8 49.6 225 10 5 8.6 4.7 24.2 75.6 -0.9 391 2.0 11750 10.4 50.7 220 10 5 8.2 4.5 24.1 75.4 -1.0 366 1.9 11500 10.9 51.6 220 10 5 7.3 4.0 24.0 75.1 -1.2 342 1.7 11250 11.4 52.5 225 10 5 7.3 4.0 23.8 74.8 -1.4 319 1.6 11000 12.0 53.6 225 10 5 7.6 4.2 23.6 74.4 -1.6 296 1.5 10750 12.5 54.5 225 10 5 7.5 4.1 23.4 74.1 -1.8 272 1.4 10500 13.0 55.4 225 10 5 7.7 4.2 23.2 73.8 -2.0 249 1.3 10250 13.6 56.5 225 10 5 7.6 4.2 23.1 73.6 -2.2 225 1.1 10000 14.1 57.4 225 9 5 7.3 4.0 22.9 73.2 -2.4 202 1.0 9750 14.6 58.3 225 9 5 7.6 4.2 22.7 72.9 -2.6 179 0.9 9500 15.2 59.4 225 9 5 6.8 3.7 22.6 72.6 -2.8 156 0.8 9250 15.6 60.1 225 8 4 5.6 3.1 22.3 72.1 -3.1 135 0.7 9000 16.0 60.8 230 7 4 5.5 3.0 22.0 71.5 -3.5 116 0.6 8750 16.4 61.5 235 7 3 5.8 3.2 21.6 71.0 -3.8 97 0.5 8500 16.8 62.2 240 6 3 5.1 2.8 21.3 70.4 -4.1 77 0.4 8250 17.1 62.8 245 6 3 3.2 1.8 20.9 69.6 -4.6 60 0.3 8000 17.2 63.0 250 5 3 -0.7 -0.4 20.3 68.5 -5.2 49 0.2 7750 16.8 62.2 250 5 3 -13.1 -7.2 19.1 66.4 -6.4 55 0.3 7500 M M M M M M M M M M M M 7250 M M M M M M M M M M M M 7000 M M M M M M M M M M M M 6750 M M M M M M M M M M M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 08/12/2024 at 0900 MDT | 08/12/2024 at 1200 MDT | CAPE... +569.2 LI... -4.1 | CAPE... +653.0 LI... -3.4 CINH... -37.9 K Index... +27.9 | CINH... -6.0 K Index... +29.9 | 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 -64.7 -84.5 255 19 10 2.4 1.3 | -64.3 -83.7 245 21 11 2.0 1.1 45000 -59.1 -74.4 260 28 14 6.1 3.4 | -59.2 -74.6 255 27 14 6.0 3.3 40000 -49.7 -57.5 260 33 17 7.0 3.8 | -49.4 -56.9 270 31 16 7.0 3.8 38000 -44.9 -48.8 255 37 19 7.0 3.8 | -45.2 -49.4 260 36 19 7.0 3.8 36000 -40.7 -41.3 250 41 21 7.3 4.0 | -41.0 -41.8 255 42 22 7.3 4.0 34000 -36.3 -33.3 255 38 19 7.4 4.1 | -36.6 -33.9 255 40 21 7.4 4.1 32000 -31.8 -25.2 260 35 18 8.0 4.4 | -32.2 -26.0 255 38 20 8.3 4.5 30000 -27.4 -17.3 260 31 16 7.4 4.1 | -27.4 -17.3 255 35 18 8.0 4.4 29000 -25.2 -13.4 260 29 15 7.4 4.1 | -25.0 -13.0 255 33 17 8.1 4.4 28000 -23.1 -9.6 255 27 14 5.4 3.0 | -22.8 -9.0 255 31 16 6.3 3.4 27000 -21.5 -6.7 255 20 10 5.4 3.0 | -20.9 -5.6 255 28 14 6.3 3.5 26000 -20.0 -4.0 250 14 7 5.4 3.0 | -19.0 -2.2 250 25 13 6.4 3.5 25000 -18.4 -1.1 245 8 4 5.8 3.2 | -17.2 1.0 240 21 11 6.4 3.5 24000 -16.4 2.5 230 7 4 7.0 3.8 | -15.3 4.5 240 20 10 6.4 3.5 23000 -13.8 7.2 215 8 4 7.0 3.9 | -13.0 8.6 235 19 10 6.4 3.5 22000 -11.9 10.6 210 9 5 5.4 3.0 | -11.2 11.8 235 18 9 6.1 3.4 21000 -10.3 13.5 210 7 3 5.4 2.9 | -9.4 15.1 225 16 8 6.1 3.4 20000 -8.7 16.3 210 4 2 5.5 3.0 | -7.6 18.3 220 14 7 6.1 3.4 19500 -7.9 17.8 210 3 2 6.8 3.7 | -6.7 19.9 215 14 7 5.8 3.2 19000 -6.6 20.1 215 4 2 8.4 4.6 | -5.9 21.4 210 13 7 5.4 3.0 18500 -5.4 22.3 220 5 2 8.5 4.7 | -5.1 22.8 205 12 6 5.2 2.9 18000 -4.2 24.4 225 6 3 8.3 4.5 | -4.2 24.4 200 11 6 7.6 4.1 17500 -3.0 26.6 235 7 4 8.3 4.6 | -3.1 26.4 200 11 6 7.6 4.2 17000 -1.8 28.8 240 9 5 8.5 4.7 | -2.0 28.4 200 11 6 7.7 4.2 16500 -0.6 30.9 235 10 5 8.6 4.7 | -0.8 30.6 200 10 5 7.9 4.3 16000 0.7 33.3 235 10 5 8.6 4.7 | 0.3 32.5 200 9 5 7.9 4.4 15500 1.9 35.4 230 10 5 8.0 4.4 | 1.4 34.5 205 8 4 7.7 4.2 15000 3.1 37.6 230 10 5 8.1 4.5 | 2.5 36.5 210 8 4 7.7 4.2 14500 4.2 39.6 225 10 5 7.4 4.1 | 3.6 38.5 210 8 4 7.7 4.2 14000 5.2 41.4 225 10 5 7.4 4.0 | 4.7 40.5 215 8 4 7.8 4.3 13500 6.3 43.3 220 10 5 6.9 3.8 | 5.8 42.4 215 8 4 7.2 4.0 13000 7.2 45.0 215 10 5 6.8 3.8 | 6.7 44.1 205 8 4 7.3 4.0 12500 8.3 46.9 215 11 5 8.3 4.6 | 8.0 46.4 200 8 4 9.0 4.9 12000 9.5 49.1 215 11 5 8.2 4.5 | 9.1 48.4 185 8 4 8.0 4.4 11750 10.0 50.0 210 11 5 7.5 4.1 | 9.7 49.5 180 8 4 8.2 4.5 11500 10.5 50.9 210 11 5 6.5 3.6 | 10.4 50.7 175 8 4 8.9 4.9 11250 11.0 51.8 210 10 5 7.2 4.0 | 11.0 51.8 170 8 4 9.2 5.1 11000 11.6 52.9 210 10 5 7.7 4.2 | 11.7 53.1 170 8 4 9.1 5.0 10750 12.1 53.8 210 10 5 7.4 4.1 | 12.4 54.3 165 9 4 9.5 5.2 10500 12.7 54.9 205 9 5 8.2 4.5 | 13.0 55.4 160 9 5 8.2 4.5 10250 13.3 55.9 205 9 4 8.3 4.5 | 13.6 56.5 160 9 5 8.7 4.8 10000 13.9 57.0 205 8 4 7.6 4.2 | 14.4 57.9 155 9 5 10.2 5.6 9750 14.4 57.9 200 7 4 7.8 4.3 | 15.1 59.2 155 9 5 10.3 5.6 9500 15.0 59.0 200 6 3 7.7 4.2 | 15.8 60.4 155 10 5 8.5 4.7 9250 15.5 59.9 200 5 3 7.1 3.9 | 16.4 61.5 155 10 5 8.6 4.7 9000 16.0 60.8 200 5 2 6.6 3.6 | 17.2 63.0 155 10 5 11.1 6.1 8750 16.4 61.5 200 4 2 6.2 3.4 | 18.0 64.4 155 10 5 10.9 6.0 8500 16.9 62.4 205 4 2 7.7 4.2 | 18.8 65.8 155 10 5 11.0 6.1 8250 17.5 63.5 205 3 2 9.9 5.4 | 19.6 67.3 150 10 5 12.1 6.6 8000 18.2 64.8 200 3 1 9.3 5.1 | 20.7 69.3 150 10 5 18.0 9.9 7750 18.9 66.0 200 3 1 12.1 6.7 | 22.3 72.1 150 10 5 25.8 14.1 7500 M M M M M M M | M M M M M M M 7250 M M M M M M M | M M M M M M M 7000 M M M M M M M | M M M M M M M 6750 M M M M M M M | M M M M M M M 08/12/2024 at 1500 MDT | 08/12/2024 at 1800 MDT | CAPE... +850.9 LI... -3.2 | CAPE... +998.2 LI... -2.8 CINH... -1.9 K Index... +30.0 | CINH... -6.4 K Index... +30.1 | 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 -63.9 -83.0 235 21 11 1.8 1.0 | -64.6 -84.3 240 19 10 1.4 0.8 45000 -59.1 -74.4 245 27 14 5.6 3.1 | -60.0 -76.0 235 24 12 5.9 3.2 40000 -49.9 -57.8 270 30 16 6.8 3.7 | -50.1 -58.2 245 19 10 7.5 4.1 38000 -45.9 -50.6 265 36 19 6.8 3.7 | -45.6 -50.1 250 24 13 7.6 4.1 36000 -41.7 -43.1 260 42 21 8.1 4.5 | -41.0 -41.8 250 29 15 8.3 4.5 34000 -36.7 -34.1 260 39 20 8.5 4.6 | -36.0 -32.8 250 27 14 8.3 4.6 32000 -31.6 -24.9 255 36 18 9.1 5.0 | -31.0 -23.8 245 25 13 9.0 4.9 30000 -26.8 -16.2 260 32 17 8.0 4.4 | -26.3 -15.3 245 23 12 8.0 4.4 29000 -24.4 -11.9 260 30 16 8.0 4.4 | -23.9 -11.0 250 23 12 8.1 4.4 28000 -22.1 -7.8 260 29 15 7.1 3.9 | -21.6 -6.9 250 22 11 6.8 3.8 27000 -20.0 -4.0 255 28 14 7.2 4.0 | -19.5 -3.1 250 21 11 7.0 3.8 26000 -17.9 -0.2 255 27 14 7.2 4.0 | -17.5 0.5 250 20 11 7.0 3.8 25000 -15.8 3.6 250 26 14 6.9 3.8 | -15.4 4.3 255 20 10 6.9 3.8 24000 -13.9 7.0 250 26 13 6.1 3.4 | -13.4 7.9 255 20 10 6.8 3.7 23000 -11.7 10.9 245 26 14 6.2 3.4 | -11.4 11.5 255 21 11 6.8 3.7 22000 -9.9 14.2 240 26 14 5.9 3.2 | -8.9 16.0 260 22 11 6.2 3.4 21000 -8.2 17.2 235 26 13 5.9 3.2 | -7.1 19.2 260 23 12 6.2 3.4 20000 -6.5 20.3 230 26 13 5.9 3.2 | -5.3 22.5 260 25 13 6.3 3.4 19500 -5.7 21.7 230 26 13 5.7 3.2 | -4.4 24.1 260 26 14 6.1 3.3 19000 -4.9 23.2 225 26 13 5.4 3.0 | -3.6 25.5 265 28 14 5.7 3.1 18500 -4.1 24.6 225 25 13 5.4 3.0 | -2.8 27.0 265 29 15 5.8 3.2 18000 -3.3 26.1 220 24 13 5.9 3.2 | -2.0 28.4 265 30 15 5.2 2.9 17500 -2.5 27.5 220 24 12 6.0 3.3 | -1.3 29.7 265 29 15 5.2 2.9 17000 -1.6 29.1 215 23 12 6.0 3.3 | -0.6 30.9 265 29 15 5.2 2.8 16500 -0.7 30.7 215 22 11 6.1 3.3 | 0.1 32.2 265 28 14 5.0 2.7 16000 0.2 32.4 210 21 11 5.9 3.2 | 0.8 33.4 260 26 13 4.8 2.7 15500 1.2 34.2 210 21 11 8.1 4.4 | 1.6 34.9 255 24 13 7.3 4.0 15000 2.3 36.1 210 20 10 7.9 4.3 | 2.6 36.7 250 22 12 7.0 3.9 14500 3.5 38.3 210 20 10 8.2 4.5 | 3.6 38.5 245 21 11 8.0 4.4 14000 4.6 40.3 205 19 10 8.3 4.6 | 4.8 40.6 245 19 10 8.2 4.5 13500 5.8 42.4 205 19 10 7.8 4.3 | 6.0 42.8 240 18 9 8.4 4.6 13000 6.8 44.2 200 17 9 7.4 4.0 | 7.2 45.0 235 16 8 9.0 4.9 12500 7.9 46.2 195 17 9 8.1 4.5 | 8.7 47.7 230 16 8 10.4 5.7 12000 9.0 48.2 190 17 9 8.2 4.5 | 10.1 50.2 225 15 8 9.6 5.3 11750 9.6 49.3 185 17 9 8.2 4.5 | 10.8 51.4 220 15 8 9.2 5.0 11500 10.2 50.4 185 17 9 8.5 4.7 | 11.4 52.5 220 14 7 8.3 4.6 11250 10.8 51.4 180 17 9 9.1 5.0 | 12.0 53.6 215 14 7 8.6 4.7 11000 11.5 52.7 180 17 9 9.3 5.1 | 12.7 54.9 210 13 7 8.8 4.8 10750 12.2 54.0 180 17 9 9.4 5.1 | 13.3 55.9 205 13 7 8.7 4.8 10500 12.9 55.2 180 17 9 9.0 5.0 | 14.0 57.2 200 13 7 8.9 4.9 10250 13.5 56.3 175 17 9 9.1 5.0 | 14.6 58.3 195 12 6 9.0 4.9 10000 14.2 57.6 175 17 9 9.4 5.1 | 15.3 59.5 190 11 6 8.8 4.8 9750 14.9 58.8 175 17 9 9.5 5.2 | 15.9 60.6 190 10 5 9.3 5.1 9500 15.6 60.1 175 16 8 8.7 4.8 | 16.6 61.9 185 10 5 7.5 4.1 9250 16.2 61.2 175 16 8 9.1 5.0 | 17.1 62.8 180 9 5 7.9 4.3 9000 17.0 62.6 175 16 8 10.5 5.7 | 17.8 64.0 180 8 4 10.4 5.7 8750 17.7 63.9 175 16 8 10.5 5.7 | 18.5 65.3 170 7 4 10.4 5.7 8500 18.5 65.3 175 16 8 10.3 5.6 | 19.3 66.7 165 6 3 9.8 5.4 8250 19.3 66.7 175 15 8 10.3 5.6 | 20.0 68.0 160 5 3 9.0 5.0 8000 20.1 68.2 175 15 8 12.6 6.9 | 20.7 69.3 155 5 2 11.4 6.2 7750 21.1 70.0 175 13 7 15.9 8.7 | 21.6 70.9 150 4 2 14.9 8.2 7500 M M M M M M M | M M M M M M M 7250 M M M M M M M | M M M M M M M 7000 M M M M M M M | M M M M M M M 6750 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). 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 Air Force Academy in Colorado Springs, Colorado at North Latitude: 38 deg 58 min 48.000 sec West Longitude: 104 deg 49 min 12.000 sec Elevation: 6572 feet (2003 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. CIN (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