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Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
248 UXUS97 KPUB 201203 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0603 MDT Thursday, June 20, 2024 This forecast is for the Air Force Academy for Thursday, June 20, 2024: If the trigger temperature of 69.3 F/20.7 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1331 ft/min (6.8 m/s) Maximum height of thermals.................. 19984 ft MSL (12354 ft AGL) Forecast maximum temperature................... 83.0 F/28.8 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................. 16671 ft MSL (9041 ft AGL) Thermal soaring outlook for Friday 06/21....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:33:53 / 20:28:13 MDT Total possible sunshine........... 14 hr 54 min 19 sec (894 min 19 sec) Altitude of sun at 13:01:03 MDT... 74.46 degrees Upper air data from numerical model forecast valid on 06/20/2024 at 0600 MDT Freezing level.................. 15750 ft MSL (8120 ft AGL) Convective condensation level... 13395 ft MSL (5765 ft AGL) Lifted condensation level....... 15623 ft MSL (7993 ft AGL) Lifted index.................... -8.6 K index......................... +27.0 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 -61.5 -78.7 230 66 34 1.1 0.6 M M M M M 45000 -58.1 -72.6 235 83 43 4.7 2.6 M M M M M 40000 -50.8 -59.4 235 65 33 5.9 3.2 M M M M M 38000 -47.3 -53.1 235 57 29 5.9 3.2 M M M M M 36000 -43.3 -45.9 235 47 24 6.1 3.3 M M M M M 34000 -39.3 -38.7 225 38 20 6.7 3.7 M M M M M 32000 -35.3 -31.5 215 30 15 6.5 3.6 M M M M M 30000 -30.9 -23.6 220 29 15 7.6 4.2 37.7 99.9 7.3 M M 29000 -28.6 -19.5 225 30 15 7.6 4.2 36.9 98.5 6.8 M M 28000 -26.3 -15.3 230 30 16 7.1 3.9 36.3 97.3 6.3 M M 27000 -24.2 -11.6 235 32 16 7.0 3.8 35.1 95.2 5.5 M M 26000 -22.2 -8.0 240 34 17 7.1 3.9 34.1 93.3 4.7 M M 25000 -20.1 -4.2 240 36 19 7.3 4.0 33.2 91.8 3.9 M M 24000 -17.9 -0.2 240 36 18 7.8 4.3 32.4 90.3 3.2 M M 23000 -15.6 3.9 235 35 18 7.8 4.3 31.7 89.1 2.6 M M 22000 -12.8 9.0 235 34 17 7.1 3.9 30.9 87.6 1.8 M M 21000 -10.8 12.6 235 32 16 6.9 3.8 29.8 85.7 0.9 M M 20000 -8.8 16.2 235 29 15 6.9 3.8 28.9 84.0 -0.1 1125 5.7 19500 -7.9 17.8 235 28 15 6.8 3.7 28.4 83.2 -0.5 1081 5.5 19000 -6.9 19.6 235 27 14 6.2 3.4 27.9 82.1 -1.0 1037 5.3 18500 -6.0 21.2 235 25 13 6.2 3.4 27.3 81.1 -1.5 994 5.1 18000 -5.0 23.0 240 23 12 7.1 3.9 26.7 80.1 -2.0 950 4.8 17500 -3.9 25.0 240 23 12 7.3 4.0 26.3 79.4 -2.4 903 4.6 17000 -2.8 27.0 245 22 11 7.5 4.1 25.9 78.7 -2.8 856 4.3 16500 -1.7 28.9 245 23 12 7.9 4.3 25.6 78.1 -3.1 807 4.1 16000 -0.5 31.1 245 24 13 7.9 4.3 25.3 77.5 -3.5 758 3.9 15500 0.6 33.1 245 26 13 8.6 4.7 25.1 77.1 -3.7 708 3.6 15000 1.9 35.4 240 27 14 8.6 4.7 24.9 76.7 -4.0 656 3.3 14500 3.1 37.6 240 28 15 8.3 4.6 24.7 76.4 -4.2 604 3.1 14000 4.3 39.7 240 29 15 8.1 4.5 24.4 75.9 -4.5 554 2.8 13500 5.4 41.7 240 29 15 7.3 4.0 24.2 75.5 -4.9 505 2.6 13000 6.3 43.3 235 29 15 6.0 3.3 23.6 74.5 -5.5 464 2.4 12500 7.1 44.8 235 30 15 6.4 3.5 23.0 73.5 -6.1 424 2.2 12000 8.0 46.4 230 29 15 6.7 3.7 22.5 72.6 -6.7 383 1.9 11750 8.5 47.3 230 29 15 6.6 3.6 22.3 72.1 -7.1 363 1.8 11500 8.8 47.8 225 29 15 4.8 2.7 22.0 71.6 -7.4 344 1.7 11250 9.1 48.4 225 29 15 3.8 2.1 21.6 70.8 -7.9 329 1.7 11000 9.4 48.9 225 27 14 4.6 2.5 21.1 70.0 -8.4 313 1.6 10750 9.6 49.3 225 26 13 3.8 2.1 20.7 69.3 -8.9 298 1.5 10500 9.9 49.8 220 25 13 6.4 3.5 20.3 68.5 -9.3 282 1.4 10250 10.4 50.7 220 23 12 4.0 2.2 20.1 68.1 -9.6 261 1.3 10000 10.4 50.7 215 21 11 -0.1 -0.1 19.4 66.9 -10.4 253 1.3 9750 10.4 50.7 210 19 10 0.7 0.4 18.7 65.6 -11.1 246 1.2 9500 10.4 50.7 205 17 9 1.7 0.9 18.0 64.4 -11.9 238 1.2 9250 10.6 51.1 195 17 9 3.3 1.8 17.5 63.4 -12.4 226 1.1 9000 10.8 51.4 190 16 8 2.4 1.3 16.9 62.5 -13.0 213 1.1 8750 10.9 51.6 180 16 8 1.3 0.7 16.3 61.4 -13.7 202 1.0 8500 11.0 51.8 170 17 9 3.4 1.8 15.8 60.4 -14.3 192 1.0 8250 11.3 52.3 165 18 9 6.5 3.6 15.4 59.8 -14.7 174 0.9 8000 11.8 53.2 160 17 9 7.0 3.8 15.2 59.4 -15.0 152 0.8 7750 12.7 54.9 155 10 5 7.4 4.1 14.8 58.6 -15.6 109 0.6 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 * * * * * * 06/20/2024 at 0900 MDT | 06/20/2024 at 1200 MDT | CAPE... +974.3 LI... -4.7 | CAPE... +1611.7 LI... -5.8 CINH... -76.2 K Index... +26.1 | CINH... -20.8 K Index... +27.3 | 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 -61.8 -79.2 230 64 33 1.2 0.7 | -62.7 -80.9 235 66 34 1.7 0.9 45000 -58.2 -72.8 230 80 41 4.8 2.6 | -58.2 -72.8 240 79 41 5.5 3.0 40000 -50.6 -59.1 230 67 34 6.7 3.7 | -49.2 -56.6 235 67 34 6.5 3.6 38000 -46.6 -51.9 230 59 31 6.8 3.7 | -45.3 -49.5 235 60 31 6.5 3.6 36000 -42.0 -43.6 235 51 26 6.6 3.6 | -41.4 -42.5 230 53 27 6.3 3.5 34000 -38.2 -36.8 230 44 23 6.3 3.5 | -37.8 -36.0 230 48 25 6.0 3.3 32000 -34.4 -29.9 225 36 19 6.4 3.5 | -34.2 -29.6 225 43 22 6.1 3.3 30000 -30.7 -23.3 230 35 18 6.2 3.4 | -30.2 -22.4 225 41 21 6.8 3.7 29000 -28.8 -19.8 230 34 18 6.2 3.4 | -28.2 -18.8 220 40 21 6.8 3.7 28000 -26.9 -16.4 235 34 17 7.0 3.8 | -26.1 -15.0 220 39 20 6.9 3.8 27000 -24.8 -12.6 235 33 17 7.2 4.0 | -24.1 -11.4 225 37 19 6.9 3.8 26000 -22.6 -8.7 240 32 17 7.3 4.0 | -22.0 -7.6 230 34 18 6.9 3.8 25000 -20.5 -4.9 245 31 16 7.3 4.0 | -19.9 -3.8 235 33 17 6.9 3.8 24000 -18.2 -0.8 245 30 15 7.9 4.3 | -17.8 -0.0 230 30 15 7.3 4.0 23000 -15.8 3.6 240 29 15 7.9 4.3 | -15.1 4.8 230 27 14 7.4 4.1 22000 -13.0 8.6 240 27 14 5.9 3.2 | -12.9 8.8 225 25 13 7.1 3.9 21000 -11.4 11.5 230 25 13 5.7 3.1 | -10.9 12.4 220 28 14 7.1 3.9 20000 -9.8 14.4 220 25 13 5.9 3.2 | -8.9 16.0 215 30 16 7.1 3.9 19500 -9.0 15.8 215 25 13 6.9 3.8 | -7.8 18.0 215 32 16 7.2 4.0 19000 -7.8 18.0 215 25 13 8.4 4.6 | -6.8 19.8 215 31 16 7.4 4.1 18500 -6.6 20.1 215 24 12 8.4 4.6 | -5.7 21.7 210 30 16 7.4 4.1 18000 -5.3 22.5 215 24 12 9.0 5.0 | -4.6 23.7 210 30 15 8.1 4.5 17500 -3.9 25.0 215 24 12 9.0 5.0 | -3.4 25.9 210 29 15 8.1 4.5 17000 -2.6 27.3 220 23 12 8.9 4.9 | -2.2 28.0 210 29 15 8.1 4.5 16500 -1.3 29.7 220 23 12 8.6 4.7 | -1.1 30.0 210 27 14 8.1 4.4 16000 -0.1 31.8 225 23 12 8.6 4.7 | 0.1 32.2 210 26 13 8.1 4.5 15500 1.2 34.2 225 23 12 8.6 4.7 | 1.3 34.3 215 25 13 7.9 4.3 15000 2.4 36.3 225 23 12 8.7 4.8 | 2.4 36.3 215 25 13 7.9 4.3 14500 3.7 38.7 230 23 12 8.4 4.6 | 3.6 38.5 220 24 12 8.2 4.5 14000 4.9 40.8 230 23 12 8.4 4.6 | 4.8 40.6 220 24 12 8.3 4.5 13500 6.1 43.0 230 24 12 8.0 4.4 | 6.0 42.8 225 23 12 7.8 4.3 13000 7.2 45.0 235 24 13 7.9 4.3 | 7.1 44.8 225 22 12 7.8 4.3 12500 8.6 47.5 235 25 13 9.2 5.0 | 8.4 47.1 230 22 11 9.3 5.1 12000 9.6 49.3 235 25 13 6.8 3.7 | 9.7 49.5 230 21 11 9.3 5.1 11750 10.0 50.0 235 25 13 7.1 3.9 | 10.4 50.7 235 21 11 8.4 4.6 11500 10.5 50.9 240 25 13 6.3 3.4 | 10.9 51.6 235 20 10 6.3 3.4 11250 10.8 51.4 235 25 13 4.3 2.4 | 11.3 52.3 235 20 10 6.4 3.5 11000 11.1 52.0 235 26 13 4.0 2.2 | 11.7 53.1 235 20 10 7.0 3.8 10750 11.3 52.3 235 26 13 3.7 2.0 | 12.2 54.0 235 20 10 7.8 4.3 10500 11.6 52.9 230 27 14 5.4 3.0 | 12.6 54.7 235 20 10 4.2 2.3 10250 11.9 53.4 230 26 13 3.5 1.9 | 12.6 54.7 230 20 10 2.3 1.3 10000 11.9 53.4 230 26 13 0.2 0.1 | 12.8 55.0 225 19 10 4.5 2.5 9750 12.0 53.6 225 26 13 2.0 1.1 | 13.0 55.4 220 17 9 4.3 2.3 9500 12.0 53.6 225 25 13 -1.7 -0.9 | 13.2 55.8 210 16 8 3.3 1.8 9250 11.6 52.9 225 24 12 -3.3 -1.8 | 13.4 56.1 205 16 8 5.8 3.2 9000 11.5 52.7 220 22 11 1.3 0.7 | 14.0 57.2 200 16 8 9.9 5.4 8750 11.6 52.9 215 20 11 1.4 0.8 | 14.8 58.6 195 16 8 10.0 5.5 8500 11.6 52.9 210 19 10 4.2 2.3 | 15.5 59.9 185 16 8 9.8 5.4 8250 12.1 53.8 205 18 9 8.2 4.5 | 16.2 61.2 185 16 8 10.1 5.5 8000 12.6 54.7 195 17 9 7.2 4.0 | 16.9 62.4 180 15 8 9.4 5.1 7750 13.2 55.8 190 16 8 9.7 5.3 | 17.7 63.9 175 15 8 16.7 9.1 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 06/20/2024 at 1500 MDT | 06/20/2024 at 1800 MDT | CAPE... +1162.9 LI... -4.3 | CAPE... +1066.0 LI... -3.7 CINH... -47.8 K Index... +22.9 | CINH... -17.7 K Index... +26.2 | 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 -63.7 -82.7 240 67 34 2.2 1.2 | -63.3 -81.9 240 58 30 2.3 1.3 45000 -58.2 -72.8 240 78 40 6.4 3.5 | -57.4 -71.3 240 70 36 6.2 3.4 40000 -48.3 -54.9 235 72 37 5.8 3.2 | -48.1 -54.6 240 71 36 5.9 3.2 38000 -44.8 -48.6 235 63 32 5.8 3.2 | -44.6 -48.3 240 62 32 5.9 3.2 36000 -41.3 -42.3 230 53 28 6.4 3.5 | -41.1 -42.0 235 54 28 6.2 3.4 34000 -37.1 -34.8 230 47 24 7.1 3.9 | -36.2 -33.2 240 46 24 7.4 4.1 32000 -32.8 -27.0 235 40 20 7.3 4.0 | -31.7 -25.1 245 40 20 7.0 3.9 30000 -29.5 -21.1 230 35 18 5.3 2.9 | -28.2 -18.8 245 33 17 5.9 3.3 29000 -27.9 -18.2 225 33 17 5.4 2.9 | -26.4 -15.5 240 30 15 5.9 3.3 28000 -26.2 -15.2 225 31 16 7.5 4.1 | -24.5 -12.1 240 27 14 7.2 3.9 27000 -23.8 -10.8 220 31 16 7.9 4.4 | -22.4 -8.3 240 26 14 7.1 3.9 26000 -21.4 -6.5 215 31 16 7.9 4.4 | -20.3 -4.5 240 26 13 7.1 3.9 25000 -19.1 -2.4 210 31 16 7.9 4.4 | -18.2 -0.8 235 25 13 7.2 3.9 24000 -16.1 3.0 210 31 16 7.9 4.4 | -16.1 3.0 235 22 11 7.2 4.0 23000 -13.7 7.3 210 32 16 8.0 4.4 | -14.0 6.8 230 20 10 7.3 4.0 22000 -11.5 11.3 210 32 16 5.9 3.3 | -11.9 10.6 225 17 9 7.3 4.0 21000 -9.8 14.4 210 31 16 5.8 3.2 | -9.7 14.5 230 18 9 7.4 4.1 20000 -8.1 17.4 215 31 16 5.9 3.2 | -7.1 19.2 235 20 10 7.6 4.2 19500 -7.3 18.9 215 31 16 6.7 3.7 | -6.0 21.2 235 21 11 7.6 4.2 19000 -6.2 20.8 215 31 16 8.1 4.4 | -4.9 23.2 230 22 11 7.7 4.2 18500 -5.0 23.0 220 32 16 8.1 4.5 | -3.8 25.2 225 22 11 7.7 4.2 18000 -3.8 25.2 220 32 16 8.6 4.7 | -2.8 27.0 225 23 12 7.1 3.9 17500 -2.6 27.3 225 32 16 8.6 4.7 | -1.7 28.9 220 24 12 7.1 3.9 17000 -1.3 29.7 225 32 17 8.8 4.8 | -0.7 30.7 220 24 13 7.5 4.1 16500 0.0 32.0 230 32 17 9.1 5.0 | 0.5 32.9 220 25 13 8.0 4.4 16000 1.3 34.3 230 32 17 9.1 5.0 | 1.6 34.9 220 25 13 8.0 4.4 15500 2.7 36.9 230 32 17 9.0 4.9 | 2.8 37.0 220 25 13 7.6 4.2 15000 4.0 39.2 235 32 17 9.0 5.0 | 3.9 39.0 220 24 13 7.7 4.2 14500 5.3 41.5 235 32 16 7.9 4.3 | 5.0 41.0 215 24 12 7.5 4.1 14000 6.4 43.5 230 29 15 7.6 4.2 | 6.1 43.0 215 23 12 7.5 4.1 13500 7.5 45.5 225 27 14 7.4 4.1 | 7.2 45.0 210 22 11 7.5 4.1 13000 8.5 47.3 220 24 12 7.1 3.9 | 8.2 46.8 205 22 11 7.2 3.9 12500 9.4 48.9 220 22 11 6.9 3.8 | 9.2 48.6 200 21 11 5.9 3.2 12000 10.3 50.5 210 21 11 6.2 3.4 | 9.8 49.6 190 23 12 4.4 2.4 11750 10.8 51.4 205 21 11 6.1 3.3 | 10.0 50.0 185 24 12 4.7 2.6 11500 11.2 52.2 205 21 11 5.4 2.9 | 10.3 50.5 185 25 13 5.5 3.0 11250 11.5 52.7 200 21 11 5.1 2.8 | 10.7 51.3 180 26 13 6.2 3.4 11000 11.9 53.4 200 22 11 5.3 2.9 | 11.1 52.0 180 26 14 6.3 3.5 10750 12.2 54.0 195 23 12 5.1 2.8 | 11.5 52.7 175 27 14 6.4 3.5 10500 12.6 54.7 195 24 12 5.8 3.2 | 11.9 53.4 175 28 14 6.1 3.4 10250 13.0 55.4 190 24 13 5.5 3.0 | 12.4 54.3 175 28 15 8.1 4.4 10000 13.3 55.9 190 25 13 4.4 2.4 | 13.1 55.6 170 28 15 9.7 5.3 9750 13.6 56.5 185 26 13 5.4 3.0 | 13.7 56.7 170 28 15 9.5 5.2 9500 14.0 57.2 185 26 14 2.7 1.5 | 14.4 57.9 170 28 14 8.8 4.8 9250 14.0 57.2 185 27 14 3.2 1.8 | 15.0 59.0 170 28 14 9.4 5.1 9000 14.3 57.7 180 26 14 7.8 4.3 | 15.7 60.3 170 28 14 11.0 6.0 8750 14.8 58.6 180 26 13 8.1 4.5 | 16.5 61.7 170 27 14 11.0 6.1 8500 15.3 59.5 175 26 13 8.5 4.7 | 17.3 63.1 170 27 14 10.5 5.7 8250 16.0 60.8 175 24 13 10.2 5.6 | 18.1 64.6 170 27 14 10.0 5.5 8000 18.7 65.7 170 20 10 30.0 16.4 | 19.0 66.2 170 25 13 14.1 7.7 7750 20.5 68.9 170 17 9 10.6 5.8 | 20.2 68.4 170 22 11 19.8 10.9 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