Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
850 UXUS97 KPUB 191203 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0603 MDT Wednesday, June 19, 2024 This forecast is for the Air Force Academy for Wednesday, June 19, 2024: If the trigger temperature of 57.6 F/14.2 C is reached...then Thermal Soaring Index....................... Poor Maximum rate of lift........................ 0 ft/min (0.0 m/s) Maximum height of thermals.................. 12987 ft MSL (5358 ft AGL) Forecast maximum temperature................... 66.0 F/19.3 C Time of trigger temperature.................... 1200 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................. 12109 ft MSL (4479 ft AGL) Thermal soaring outlook for Thursday 06/20..... Good Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:33:41 / 20:27:59 MDT Total possible sunshine........... 14 hr 54 min 17 sec (894 min 17 sec) Altitude of sun at 13:00:50 MDT... 74.45 degrees Upper air data from numerical model forecast valid on 06/19/2024 at 0600 MDT Freezing level.................. 15483 ft MSL (7854 ft AGL) Convective condensation level... 16360 ft MSL (8731 ft AGL) Lifted condensation level....... 14420 ft MSL (6791 ft AGL) Lifted index.................... +1.1 K index......................... +19.1 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 -60.4 -76.7 225 70 36 2.3 1.3 M M M M M 45000 -56.9 -70.4 225 74 38 2.0 1.1 M M M M M 40000 -53.6 -64.5 225 58 30 5.8 3.2 M M M M M 38000 -50.3 -58.5 220 56 29 5.5 3.0 M M M M M 36000 -47.0 -52.6 215 53 27 5.6 3.0 M M M M M 34000 -42.1 -43.8 215 51 26 7.8 4.3 M M M M M 32000 -37.5 -35.5 220 50 26 7.8 4.3 M M M M M 30000 -32.8 -27.0 225 48 24 7.7 4.2 36.0 96.7 13.3 M M 29000 -30.5 -22.9 225 46 24 7.7 4.2 35.2 95.4 12.8 M M 28000 -28.2 -18.8 225 45 23 7.7 4.2 34.6 94.2 12.5 M M 27000 -25.9 -14.6 230 44 23 7.6 4.2 33.7 92.7 11.9 M M 26000 -23.6 -10.5 225 44 23 7.6 4.2 32.9 91.2 11.4 M M 25000 -21.3 -6.3 225 43 22 7.7 4.2 32.2 90.0 11.0 M M 24000 -19.3 -2.7 225 43 22 6.6 3.6 31.2 88.1 10.3 M M 23000 -17.3 0.9 230 42 22 6.6 3.6 30.0 86.0 9.4 M M 22000 -15.4 4.3 230 41 21 6.6 3.6 29.0 84.1 8.6 M M 21000 -13.1 8.4 225 42 21 6.3 3.5 27.4 81.4 7.3 M M 20000 -11.3 11.7 225 43 22 6.7 3.7 26.3 79.3 6.2 M M 19500 -10.4 13.3 225 44 22 6.7 3.7 25.8 78.5 5.7 M M 19000 -9.3 15.3 220 43 22 9.2 5.1 25.5 78.0 5.4 M M 18500 -7.9 17.8 225 40 21 9.1 5.0 25.4 77.8 5.3 M M 18000 -6.5 20.3 225 37 19 9.0 4.9 25.3 77.6 5.3 M M 17500 -5.2 22.6 225 35 18 8.7 4.8 25.2 77.3 5.2 M M 17000 -3.9 25.0 225 33 17 8.7 4.8 25.0 77.0 5.0 M M 16500 -2.6 27.3 230 31 16 8.9 4.9 24.8 76.7 4.9 M M 16000 -1.3 29.7 225 29 15 8.8 4.9 24.7 76.5 4.8 M M 15500 -0.0 32.0 225 26 14 7.6 4.2 24.5 76.2 4.7 M M 15000 1.0 33.8 220 24 12 6.7 3.7 24.0 75.3 4.2 M M 14500 2.0 35.6 215 21 11 5.5 3.0 23.6 74.4 3.8 M M 14000 2.3 36.1 205 20 10 1.5 0.8 22.4 72.3 2.7 M M 13500 2.5 36.5 195 19 10 1.7 0.9 21.1 70.0 1.4 M M 13000 2.7 36.9 185 19 10 1.9 1.0 19.8 67.7 0.1 M M 12500 2.5 36.5 180 19 10 -2.7 -1.5 18.3 64.9 -1.5 368 1.9 12000 2.3 36.1 175 18 9 0.5 0.3 16.6 61.8 -3.2 361 1.8 11750 2.3 36.1 170 17 9 0.8 0.5 15.8 60.5 -3.9 354 1.8 11500 2.3 36.1 170 16 8 -1.6 -0.9 15.1 59.2 -4.7 347 1.8 11250 2.1 35.8 165 16 8 0.9 0.5 14.2 57.6 -5.6 345 1.8 11000 2.4 36.3 165 15 8 5.9 3.3 13.8 56.8 -6.0 327 1.7 10750 2.8 37.0 160 14 7 5.5 3.0 13.5 56.2 -6.3 307 1.6 10500 3.3 37.9 155 14 7 4.8 2.6 13.1 55.6 -6.7 288 1.5 10250 3.6 38.5 155 12 6 4.1 2.2 12.7 54.9 -7.1 271 1.4 10000 3.9 39.0 150 13 7 4.8 2.6 12.3 54.1 -7.5 253 1.3 9750 4.3 39.7 150 13 7 5.0 2.7 11.9 53.5 -7.9 234 1.2 9500 4.7 40.5 150 13 7 4.8 2.6 11.6 52.8 -8.2 215 1.1 9250 5.1 41.2 150 14 7 6.5 3.6 11.2 52.2 -8.6 196 1.0 9000 5.6 42.1 145 14 7 7.5 4.1 11.1 51.9 -8.8 174 0.9 8750 6.1 43.0 145 14 7 7.0 3.8 10.8 51.5 -9.1 151 0.8 8500 6.6 43.9 145 14 7 6.8 3.7 10.6 51.2 -9.3 129 0.7 8250 7.1 44.8 145 13 7 5.4 3.0 10.4 50.7 -9.6 107 0.5 8000 7.5 45.5 145 11 6 4.1 2.2 10.0 50.0 -9.9 86 0.4 7750 8.2 46.8 205 3 2 4.4 2.4 9.1 48.4 -10.6 49 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 * * * * * * 06/19/2024 at 0900 MDT | 06/19/2024 at 1200 MDT | CAPE... 0.0 LI... +0.4 | CAPE... +1.2 LI... -1.2 CINH... 0.0 K Index... +20.2 | CINH... 0.0 K Index... +22.9 | 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 -60.2 -76.4 225 76 39 2.6 1.4 | -59.8 -75.6 220 74 38 2.1 1.1 45000 -56.4 -69.5 220 89 46 2.3 1.3 | -56.4 -69.5 220 92 48 2.8 1.6 40000 -52.7 -62.9 220 72 37 5.4 3.0 | -52.0 -61.6 220 76 39 4.5 2.5 38000 -49.6 -57.3 220 64 33 5.1 2.8 | -49.1 -56.4 220 67 35 4.3 2.4 36000 -46.2 -51.2 215 56 29 4.9 2.7 | -46.5 -51.7 220 59 31 4.1 2.3 34000 -42.0 -43.6 215 52 27 7.4 4.1 | -42.2 -44.0 220 54 28 7.8 4.3 32000 -37.5 -35.5 220 49 25 7.4 4.1 | -37.6 -35.7 225 48 25 7.7 4.2 30000 -32.8 -27.0 220 45 23 8.1 4.4 | -32.9 -27.2 225 44 23 7.8 4.3 29000 -30.4 -22.7 220 43 22 8.1 4.4 | -30.6 -23.1 220 43 22 7.8 4.3 28000 -27.9 -18.2 225 41 21 8.0 4.4 | -28.3 -18.9 220 41 21 7.5 4.1 27000 -25.7 -14.3 225 41 21 7.5 4.1 | -26.3 -15.3 220 42 21 6.6 3.6 26000 -23.4 -10.1 225 40 21 7.5 4.1 | -24.3 -11.7 220 43 22 6.7 3.7 25000 -21.2 -6.2 225 40 21 7.6 4.2 | -22.3 -8.1 220 44 22 6.7 3.7 24000 -19.1 -2.4 225 41 21 6.6 3.6 | -20.0 -4.0 220 43 22 8.8 4.8 23000 -17.1 1.2 230 41 21 6.7 3.7 | -16.7 1.9 220 41 21 8.8 4.8 22000 -14.7 5.5 230 42 22 6.8 3.7 | -14.1 6.6 220 40 20 7.9 4.3 21000 -12.7 9.1 225 42 22 7.0 3.8 | -12.1 10.2 220 39 20 6.7 3.7 20000 -10.7 12.7 225 42 22 7.1 3.9 | -10.1 13.8 220 38 20 6.7 3.7 19500 -9.7 14.5 220 43 22 7.0 3.9 | -9.1 15.6 220 38 19 6.7 3.7 19000 -8.6 16.5 220 41 21 8.2 4.5 | -7.9 17.8 220 38 19 8.6 4.7 18500 -7.4 18.7 220 39 20 8.1 4.4 | -6.7 19.9 220 37 19 8.4 4.6 18000 -6.1 21.0 220 36 19 8.2 4.5 | -5.5 22.1 225 37 19 8.2 4.5 17500 -4.9 23.2 220 35 18 8.2 4.5 | -4.3 24.3 220 35 18 8.1 4.4 17000 -3.7 25.3 220 33 17 8.3 4.5 | -3.1 26.4 220 34 17 8.1 4.4 16500 -2.5 27.5 220 31 16 7.9 4.3 | -1.9 28.6 220 32 16 7.9 4.3 16000 -1.4 29.5 220 29 15 8.0 4.4 | -0.7 30.7 220 30 16 7.9 4.4 15500 -0.2 31.6 215 27 14 7.0 3.9 | 0.3 32.5 220 29 15 6.3 3.4 15000 0.7 33.3 215 27 14 6.7 3.7 | 1.1 34.0 220 28 14 5.8 3.2 14500 1.7 35.1 210 26 14 5.4 3.0 | 1.9 35.4 215 27 14 3.8 2.1 14000 2.2 36.0 205 26 13 3.2 1.8 | 2.0 35.6 205 25 13 0.9 0.5 13500 2.6 36.7 200 25 13 3.1 1.7 | 2.0 35.6 195 25 13 1.9 1.0 13000 2.9 37.2 195 24 12 2.4 1.3 | 2.6 36.7 185 24 12 6.7 3.7 12500 3.0 37.4 185 23 12 1.4 0.7 | 3.6 38.5 175 23 12 8.2 4.5 12000 3.1 37.6 180 22 11 1.2 0.7 | 4.3 39.7 170 21 11 3.9 2.1 11750 3.2 37.8 175 21 11 1.3 0.7 | 4.7 40.5 165 20 10 4.4 2.4 11500 3.3 37.9 170 20 10 1.2 0.7 | 5.0 41.0 160 19 10 4.1 2.2 11250 3.4 38.1 170 20 10 2.4 1.3 | 5.2 41.4 160 18 9 2.0 1.1 11000 3.6 38.5 165 19 10 3.4 1.9 | 5.3 41.5 160 16 8 0.6 0.3 10750 3.8 38.8 165 17 9 3.1 1.7 | 5.3 41.5 160 15 8 1.0 0.6 10500 4.1 39.4 165 16 8 3.3 1.8 | 5.4 41.7 155 13 7 0.6 0.4 10250 4.3 39.7 160 15 8 2.1 1.2 | 5.5 41.9 155 12 6 0.9 0.5 10000 4.4 39.9 155 15 7 1.2 0.7 | 5.6 42.1 160 11 6 1.4 0.8 9750 4.5 40.1 155 15 7 1.4 0.8 | 5.7 42.3 160 10 5 1.1 0.6 9500 4.6 40.3 150 15 7 1.6 0.9 | 5.8 42.4 165 10 5 1.8 1.0 9250 4.8 40.6 150 15 8 3.9 2.1 | 6.0 42.8 170 9 5 4.4 2.4 9000 5.1 41.2 145 14 7 5.7 3.1 | 6.4 43.5 170 9 5 5.2 2.8 8750 5.5 41.9 145 13 7 5.3 2.9 | 6.7 44.1 170 8 4 4.0 2.2 8500 5.9 42.6 145 12 6 6.3 3.4 | 7.0 44.6 170 7 4 5.8 3.2 8250 6.5 43.7 150 11 6 8.0 4.4 | 7.6 45.7 170 7 4 9.0 4.9 8000 7.2 45.0 150 10 5 11.1 6.1 | 8.3 46.9 175 6 3 9.0 4.9 7750 8.2 46.8 150 9 4 15.4 8.5 | 8.9 48.0 170 6 3 11.4 6.3 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 06/19/2024 at 1500 MDT | 06/19/2024 at 1800 MDT | CAPE... +164.2 LI... +0.6 | CAPE... +163.7 LI... -0.8 CINH... -175.3 K Index... +19.9 | CINH... -214.1 K Index... +23.2 | 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 -60.1 -76.2 225 74 38 2.0 1.1 | -61.0 -77.8 225 69 36 1.8 1.0 45000 -56.7 -70.1 225 89 46 2.9 1.6 | -57.6 -71.7 225 84 43 3.0 1.7 40000 -51.7 -61.1 230 58 30 5.3 2.9 | -52.6 -62.7 230 53 27 6.3 3.4 38000 -48.5 -55.3 235 50 26 5.4 3.0 | -48.8 -55.8 230 45 23 6.4 3.5 36000 -45.2 -49.4 240 41 21 5.4 2.9 | -45.0 -49.0 235 38 19 6.3 3.5 34000 -41.3 -42.3 240 42 22 6.6 3.6 | -40.5 -40.9 235 36 19 7.7 4.2 32000 -37.4 -35.3 230 45 23 6.6 3.6 | -35.3 -31.5 240 37 19 7.7 4.2 30000 -32.8 -27.0 230 45 23 8.0 4.4 | -31.1 -24.0 240 37 19 6.9 3.8 29000 -30.4 -22.7 230 44 23 8.0 4.4 | -29.1 -20.4 240 37 19 6.9 3.8 28000 -28.0 -18.4 230 43 22 7.7 4.2 | -27.0 -16.6 240 38 19 7.3 4.0 27000 -25.9 -14.6 225 44 22 7.0 3.8 | -24.8 -12.6 235 37 19 7.5 4.1 26000 -23.8 -10.8 225 44 23 7.0 3.9 | -22.5 -8.5 235 37 19 7.5 4.1 25000 -21.7 -7.1 225 45 23 7.0 3.9 | -20.3 -4.5 230 37 19 7.5 4.1 24000 -18.8 -1.8 225 45 23 8.1 4.5 | -18.1 -0.6 230 38 19 7.4 4.1 23000 -16.4 2.5 225 44 23 8.2 4.5 | -16.0 3.2 230 38 20 7.5 4.1 22000 -14.1 6.6 225 44 22 8.3 4.6 | -13.8 7.2 230 39 20 7.6 4.2 21000 -11.6 11.1 225 42 21 8.4 4.6 | -11.5 11.3 235 38 20 8.0 4.4 20000 -9.1 15.6 225 40 20 8.5 4.6 | -9.1 15.6 235 38 19 8.0 4.4 19500 -7.9 17.8 230 39 20 8.5 4.7 | -7.4 18.7 235 38 19 7.9 4.4 19000 -6.8 19.8 230 38 19 6.3 3.4 | -6.3 20.7 235 38 19 7.5 4.1 18500 -5.8 21.6 230 37 19 6.5 3.5 | -5.2 22.6 235 38 19 7.5 4.1 18000 -4.8 23.4 230 37 19 6.3 3.5 | -4.1 24.6 235 38 20 7.5 4.1 17500 -3.9 25.0 230 36 18 6.2 3.4 | -3.0 26.6 235 37 19 7.4 4.1 17000 -2.9 26.8 230 35 18 6.2 3.4 | -1.9 28.6 235 37 19 7.4 4.1 16500 -1.8 28.8 230 34 17 8.5 4.7 | -0.8 30.6 235 36 19 7.4 4.1 16000 -0.6 30.9 230 32 16 8.3 4.5 | 0.2 32.4 230 36 18 7.5 4.1 15500 0.7 33.3 230 30 15 8.7 4.7 | 1.3 34.3 230 35 18 7.6 4.2 15000 2.0 35.6 230 27 14 8.7 4.8 | 2.3 36.1 225 33 17 7.7 4.2 14500 3.3 37.9 225 24 12 8.3 4.5 | 3.4 38.1 225 31 16 7.7 4.2 14000 4.4 39.9 220 23 12 7.7 4.2 | 4.5 40.1 220 29 15 7.6 4.2 13500 5.5 41.9 215 23 12 7.0 3.8 | 5.6 42.1 220 26 13 7.3 4.0 13000 6.1 43.0 210 22 11 3.1 1.7 | 6.5 43.7 210 25 13 6.4 3.5 12500 6.6 43.9 200 22 11 5.0 2.8 | 7.6 45.7 210 24 12 7.8 4.3 12000 6.8 44.2 195 22 12 0.5 0.3 | 8.3 46.9 205 23 12 3.3 1.8 11750 6.8 44.2 195 22 12 1.5 0.8 | 8.5 47.3 205 24 12 3.7 2.0 11500 6.8 44.2 195 22 12 -1.1 -0.6 | 8.8 47.8 200 24 12 4.0 2.2 11250 6.6 43.9 190 22 12 -0.2 -0.1 | 9.0 48.2 200 23 12 2.6 1.4 11000 6.7 44.1 190 21 11 2.8 1.5 | 9.1 48.4 200 23 12 1.2 0.6 10750 6.9 44.4 190 20 11 1.4 0.8 | 9.2 48.6 200 22 12 1.8 1.0 10500 7.0 44.6 190 20 10 3.9 2.2 | 9.3 48.7 200 22 11 0.8 0.5 10250 7.3 45.1 190 18 9 4.9 2.7 | 9.2 48.6 195 22 11 -1.0 -0.6 10000 7.6 45.7 185 17 9 3.2 1.8 | 9.1 48.4 195 21 11 -1.5 -0.8 9750 7.8 46.0 180 16 8 3.9 2.1 | 8.9 48.0 190 20 10 -1.4 -0.7 9500 8.0 46.4 170 15 8 2.9 1.6 | 8.8 47.8 190 20 10 -1.3 -0.7 9250 8.3 46.9 170 14 7 5.7 3.1 | 8.8 47.8 185 19 10 5.4 3.0 9000 8.9 48.0 165 14 7 10.8 5.9 | 9.5 49.1 180 18 9 10.4 5.7 8750 9.8 49.6 165 14 7 11.7 6.4 | 10.2 50.4 180 18 9 9.3 5.1 8500 10.6 51.1 165 14 7 11.2 6.1 | 10.9 51.6 175 18 9 9.4 5.2 8250 11.4 52.5 160 14 7 10.9 6.0 | 11.6 52.9 170 18 9 9.3 5.1 8000 12.5 54.5 160 14 7 19.0 10.5 | 12.4 54.3 170 17 9 14.8 8.1 7750 14.4 57.9 160 13 7 32.2 17.6 | 13.8 56.8 170 16 8 23.5 12.9 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