Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
286 UXUS97 KBOU 050044 SRGBOU Soaring Forecast National Weather Service Denver/Boulder, Colorado 1843 MDT Saturday, May 4, 2024 This forecast is for Sunday, May 5, 2024: If the trigger temperature of 70.0 F/21.1 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 1127 ft/min (5.7 m/s) Maximum height of thermals.................. 19248 ft MSL (13940 ft AGL) Forecast maximum temperature................... 79.0 F/26.6 C Time of trigger temperature.................... 1230 MDT Time of overdevelopment........................ 1600 MDT Middle/high clouds during soaring window....... Broken/overcast thin middle Surface winds during soaring window............ Between 20 mph and 30 mph Height of the -3 thermal index................. 14062 ft MSL (8754 ft AGL) Thermal soaring outlook for Monday 05/06....... Poor Wave Soaring Index............................. Poor Wave Soaring Index trend (to 1800 MDT)......... Becoming fair Height of stable layer (12-18K ft MSL)......... None Weak PVA/NVA (through 1800 MDT)................ Neither Potential height of wave....................... 30708 ft MSL (25400 ft AGL) Wave soaring outlook for Monday 05/06.......... Good Remarks... Sunrise/Sunset.................... 05:54:08 / 19:58:06 MDT Total possible sunshine........... 14 hr 3 min 58 sec (843 min 58 sec) Altitude of sun at 12:56:07 MDT... 66.77 degrees Upper air data from numerical model forecast valid on 05/05/2024 at 0600 MDT Freezing level.................. 12678 ft MSL (7370 ft AGL) Convective condensation level... 16101 ft MSL (10793 ft AGL) Lifted condensation level....... 17016 ft MSL (11708 ft AGL) Lifted index.................... -2.0 K index......................... +5.7 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 -57.5 -71.5 245 37 19 -0.1 -0.0 M M M M M 45000 -57.8 -72.0 245 37 19 -2.3 -1.3 M M M M M 40000 -61.3 -78.3 270 34 18 -2.4 -1.3 M M M M M 38000 -58.9 -74.0 270 34 17 7.7 4.2 M M M M M 36000 -53.8 -64.8 270 32 17 7.7 4.2 M M M M M 34000 -48.9 -56.0 270 31 16 8.7 4.7 M M M M M 32000 -43.7 -46.7 270 29 15 8.6 4.7 M M M M M 30000 -38.7 -37.7 265 27 14 7.9 4.3 37.3 99.1 8.5 M M 29000 -36.3 -33.3 260 27 14 7.9 4.3 36.5 97.7 7.9 M M 28000 -33.9 -29.0 255 26 14 7.9 4.3 35.8 96.5 7.5 M M 27000 -31.7 -25.1 255 26 13 6.1 3.3 35.1 95.1 7.0 M M 26000 -29.8 -21.6 245 25 13 6.1 3.4 33.6 92.4 5.9 M M 25000 -28.0 -18.4 240 25 13 6.2 3.4 32.2 90.0 4.9 M M 24000 -26.1 -15.0 235 25 13 6.3 3.5 31.0 87.8 4.0 M M 23000 -24.2 -11.6 230 24 12 6.4 3.5 29.7 85.4 2.9 M M 22000 -22.3 -8.1 220 24 12 6.4 3.5 28.5 83.3 1.9 M M 21000 -20.3 -4.5 215 23 12 7.8 4.3 27.4 81.4 1.1 M M 20000 -18.0 -0.4 215 21 11 7.9 4.3 26.7 80.1 0.5 M M 19500 -16.8 1.8 210 21 11 7.9 4.3 26.4 79.5 0.2 M M 19000 -15.6 3.9 210 20 10 7.9 4.3 26.1 79.0 -0.1 1314 6.7 18500 -13.8 7.2 210 19 10 8.0 4.4 25.7 78.2 -0.5 1238 6.3 18000 -12.6 9.3 210 18 9 8.0 4.4 25.4 77.7 -0.7 1188 6.0 17500 -11.4 11.5 210 17 9 8.0 4.4 25.1 77.2 -1.0 1137 5.8 17000 -10.2 13.6 215 17 9 8.0 4.4 24.8 76.6 -1.3 1086 5.5 16500 -9.0 15.8 215 16 8 8.0 4.4 24.5 76.1 -1.6 1036 5.3 16000 -7.9 17.8 220 15 8 7.9 4.3 24.2 75.5 -1.9 986 5.0 15500 -6.7 19.9 225 15 8 7.9 4.3 23.9 74.9 -2.2 936 4.8 15000 -5.5 22.1 230 14 7 8.1 4.4 23.6 74.4 -2.5 886 4.5 14500 -4.3 24.3 235 14 7 8.1 4.4 23.3 73.9 -2.8 836 4.2 14000 -3.1 26.4 235 14 7 8.2 4.5 23.0 73.4 -3.1 785 4.0 13500 -1.9 28.6 240 13 7 8.3 4.5 22.8 73.0 -3.3 734 3.7 13000 -0.7 30.7 240 13 7 8.5 4.7 22.5 72.6 -3.6 683 3.5 12500 0.6 33.1 240 13 7 8.7 4.8 22.3 72.2 -3.8 629 3.2 12000 1.9 35.4 240 13 6 8.9 4.9 22.2 71.9 -4.0 576 2.9 11500 3.2 37.8 235 13 7 9.1 5.0 22.1 71.7 -4.1 520 2.6 11000 4.6 40.3 235 13 7 8.5 4.7 22.0 71.6 -4.3 465 2.4 10500 5.7 42.3 235 14 7 7.0 3.9 21.7 71.1 -4.6 415 2.1 10250 6.3 43.3 235 14 7 10.9 6.0 21.5 70.8 -4.7 390 2.0 10000 7.3 45.1 235 14 7 11.8 6.5 21.8 71.3 -4.5 354 1.8 9750 7.9 46.2 235 15 8 8.1 4.4 21.7 71.1 -4.6 327 1.7 9500 8.6 47.5 235 15 8 9.2 5.0 21.7 71.0 -4.7 300 1.5 9250 9.2 48.6 235 15 8 7.8 4.3 21.6 70.9 -4.8 273 1.4 9000 9.7 49.5 230 16 8 6.4 3.5 21.4 70.5 -5.0 251 1.3 8750 10.2 50.4 230 16 8 6.8 3.8 21.1 70.0 -5.3 229 1.2 8500 10.7 51.3 230 16 8 7.3 4.0 20.9 69.6 -5.6 207 1.1 8250 11.2 52.2 230 16 8 6.6 3.6 20.7 69.3 -5.8 184 0.9 8000 11.6 52.9 230 16 8 3.3 1.8 20.4 68.6 -6.2 166 0.8 7750 11.7 53.1 230 16 8 1.4 0.8 19.7 67.5 -6.8 156 0.8 7500 11.8 53.2 230 15 8 2.4 1.3 19.1 66.5 -7.5 145 0.7 7250 11.9 53.4 230 14 7 0.9 0.5 18.6 65.4 -8.1 134 0.7 7000 11.8 53.2 230 14 7 -0.9 -0.5 17.8 64.0 -8.9 128 0.7 6750 11.7 53.1 230 14 7 -3.9 -2.2 16.9 62.4 -9.8 126 0.6 6500 11.2 52.2 230 14 7 -5.9 -3.3 15.7 60.3 -11.1 132 0.7 6250 10.7 51.3 230 13 7 -8.3 -4.5 14.5 58.1 -12.3 140 0.7 6000 9.9 49.8 225 12 6 -11.2 -6.1 13.0 55.3 -13.9 157 0.8 5750 9.1 48.4 220 12 6 -9.0 -4.9 11.5 52.6 -15.5 174 0.9 5500 8.4 47.1 210 9 4 -9.5 -5.2 10.1 50.1 -16.9 187 0.9 * * * * * * Numerical weather prediction model forecast data valid * * * * * * 05/05/2024 at 0900 MDT | 05/05/2024 at 1200 MDT | CAPE... +47.6 LI... +1.7 | CAPE... +67.0 LI... +0.1 CINH... -82.0 K Index... +6.0 | CINH... -35.3 K Index... +8.9 | 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 -56.7 -70.1 240 34 18 -0.9 -0.5 | -57.2 -71.0 235 36 18 0.0 0.0 45000 -58.0 -72.4 245 35 18 -1.7 -0.9 | -57.3 -71.1 240 39 20 -2.5 -1.4 40000 -60.5 -76.9 255 48 25 -1.7 -1.0 | -60.8 -77.4 255 62 32 -2.4 -1.3 38000 -58.3 -72.9 255 49 25 6.8 3.7 | -57.8 -72.0 255 63 32 7.8 4.3 36000 -53.8 -64.8 250 47 24 6.8 3.7 | -53.1 -63.6 255 60 31 7.8 4.3 34000 -49.3 -56.7 250 45 23 8.6 4.7 | -48.5 -55.3 250 56 29 7.7 4.2 32000 -44.1 -47.4 245 43 22 8.6 4.7 | -43.8 -46.8 245 48 25 7.7 4.2 30000 -39.1 -38.4 245 41 21 8.0 4.4 | -39.2 -38.6 235 44 23 8.0 4.4 29000 -36.7 -34.1 240 39 20 8.0 4.4 | -36.8 -34.2 235 44 22 8.0 4.4 28000 -34.3 -29.7 240 37 19 8.1 4.4 | -34.4 -29.9 235 43 22 8.0 4.4 27000 -32.0 -25.6 240 35 18 6.1 3.3 | -32.0 -25.6 235 43 22 8.0 4.4 26000 -30.2 -22.4 235 33 17 6.1 3.4 | -29.6 -21.3 235 41 21 8.1 4.4 25000 -28.3 -18.9 230 31 16 6.1 3.4 | -27.2 -17.0 235 39 20 8.1 4.4 24000 -26.5 -15.7 225 30 15 6.6 3.6 | -24.8 -12.6 235 37 19 7.3 4.0 23000 -24.4 -11.9 225 28 14 6.9 3.8 | -22.8 -9.0 230 35 18 6.9 3.8 22000 -22.4 -8.3 220 26 13 6.9 3.8 | -20.7 -5.3 230 34 17 6.9 3.8 21000 -20.2 -4.4 220 24 13 8.2 4.5 | -18.7 -1.7 225 32 16 6.9 3.8 20000 -17.7 0.1 220 23 12 8.2 4.5 | -16.1 3.0 220 31 16 6.9 3.8 19500 -15.9 3.4 220 23 12 8.2 4.5 | -15.1 4.8 220 30 15 6.9 3.8 19000 -14.7 5.5 220 22 11 8.2 4.5 | -14.0 6.8 220 30 15 6.9 3.8 18500 -13.5 7.7 220 22 11 8.1 4.4 | -13.0 8.6 220 29 15 7.1 3.9 18000 -12.2 10.0 220 22 11 8.1 4.4 | -11.9 10.6 220 29 15 7.1 3.9 17500 -11.0 12.2 220 21 11 8.0 4.4 | -10.8 12.6 215 29 15 7.4 4.1 17000 -9.8 14.4 220 21 11 8.0 4.4 | -9.7 14.5 215 29 15 7.6 4.2 16500 -8.6 16.5 215 21 11 8.0 4.4 | -8.5 16.7 215 28 15 7.6 4.2 16000 -7.4 18.7 215 21 11 8.2 4.5 | -7.4 18.7 215 28 15 7.8 4.3 15500 -6.2 20.8 215 21 11 8.2 4.5 | -6.2 20.8 215 28 14 7.8 4.3 15000 -5.0 23.0 215 21 11 8.1 4.5 | -5.0 23.0 215 28 14 7.9 4.3 14500 -3.8 25.2 215 21 11 8.2 4.5 | -3.9 25.0 215 28 14 7.9 4.3 14000 -2.6 27.3 215 21 11 8.1 4.5 | -2.7 27.1 215 28 14 8.0 4.4 13500 -1.4 29.5 215 21 11 8.1 4.5 | -1.5 29.3 215 28 14 8.0 4.4 13000 -0.2 31.6 215 21 11 8.1 4.4 | -0.3 31.5 215 27 14 8.1 4.4 12500 1.0 33.8 215 21 11 8.0 4.4 | 0.9 33.6 215 27 14 8.2 4.5 12000 2.1 35.8 215 21 11 8.0 4.4 | 2.1 35.8 215 27 14 8.1 4.5 11500 3.3 37.9 215 21 11 8.0 4.4 | 3.3 37.9 210 27 14 8.0 4.4 11000 4.5 40.1 210 21 11 7.6 4.1 | 4.4 39.9 210 26 13 7.7 4.2 10500 5.5 41.9 210 21 11 6.3 3.4 | 5.5 41.9 205 25 13 6.5 3.5 10250 6.0 42.8 210 21 11 9.7 5.3 | 6.0 42.8 205 24 13 9.9 5.5 10000 6.9 44.4 210 20 10 10.8 5.9 | 6.9 44.4 205 24 12 11.4 6.3 9750 7.5 45.5 210 20 10 7.6 4.2 | 7.6 45.7 205 23 12 8.3 4.6 9500 8.1 46.6 210 20 10 7.7 4.2 | 8.2 46.8 205 23 12 8.3 4.5 9250 8.7 47.7 210 20 10 8.7 4.8 | 8.8 47.8 205 23 12 8.7 4.8 9000 9.3 48.7 215 20 10 8.6 4.7 | 9.5 49.1 205 23 12 8.7 4.8 8750 9.9 49.8 215 20 10 7.5 4.1 | 10.1 50.2 200 22 11 8.1 4.4 8500 10.5 50.9 215 20 10 7.8 4.3 | 10.6 51.1 200 21 11 8.2 4.5 8250 11.0 51.8 215 19 10 7.6 4.2 | 11.2 52.2 200 21 11 8.0 4.4 8000 11.5 52.7 215 19 10 6.0 3.3 | 11.8 53.2 195 20 10 7.8 4.3 7750 11.9 53.4 215 19 10 4.7 2.6 | 12.3 54.1 195 19 10 8.4 4.6 7500 12.2 54.0 215 18 9 5.6 3.1 | 13.0 55.4 195 19 10 9.0 4.9 7250 12.6 54.7 215 17 9 3.4 1.9 | 13.6 56.5 195 18 9 8.2 4.5 7000 12.7 54.9 215 16 8 -0.6 -0.3 | 14.1 57.4 190 18 9 7.3 4.0 6750 12.5 54.5 215 16 8 -1.6 -0.9 | 14.7 58.5 190 17 9 9.6 5.3 6500 12.4 54.3 210 14 7 -2.1 -1.1 | 15.6 60.1 190 17 8 11.6 6.4 6250 12.2 54.0 205 13 7 0.8 0.5 | 16.4 61.5 190 16 8 10.3 5.6 6000 12.4 54.3 200 12 6 3.1 1.7 | 17.1 62.8 190 15 8 9.5 5.2 5750 12.5 54.5 195 12 6 3.6 2.0 | 17.8 64.0 185 15 8 10.1 5.5 5500 13.0 55.4 195 9 5 10.9 6.0 | 18.7 65.7 185 13 7 14.4 7.9 05/05/2024 at 1500 MDT | 05/05/2024 at 1800 MDT | CAPE... +5.9 LI... +1.6 | CAPE... +26.9 LI... +0.3 CINH... -1.2 K Index... +15.5 | CINH... -15.0 K Index... +20.9 | 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 -59.3 -74.7 225 39 20 -2.3 -1.3 | -58.3 -72.9 230 33 17 -2.2 -1.2 45000 -62.7 -80.9 230 48 25 1.2 0.7 | -61.3 -78.3 230 44 23 0.7 0.4 40000 -60.4 -76.7 250 64 33 1.5 0.8 | -60.2 -76.4 240 64 33 0.8 0.5 38000 -56.9 -70.4 250 64 33 7.4 4.0 | -56.9 -70.4 240 68 35 7.1 3.9 36000 -52.4 -62.3 250 63 32 7.4 4.0 | -52.6 -62.7 240 70 36 7.1 3.9 34000 -47.8 -54.0 245 60 31 8.4 4.6 | -48.0 -54.4 240 70 36 8.5 4.7 32000 -42.8 -45.0 245 55 28 8.4 4.6 | -42.9 -45.2 240 65 34 8.5 4.7 30000 -37.9 -36.2 240 50 26 8.0 4.4 | -37.8 -36.0 235 60 31 8.4 4.6 29000 -34.9 -30.8 235 47 24 8.0 4.4 | -35.3 -31.5 235 58 30 8.4 4.6 28000 -32.5 -26.5 235 45 23 8.0 4.4 | -32.2 -26.0 235 55 28 8.4 4.6 27000 -30.1 -22.2 235 44 23 8.0 4.4 | -29.8 -21.6 235 53 27 7.5 4.1 26000 -27.7 -17.9 235 44 23 8.0 4.4 | -27.6 -17.7 230 51 26 7.6 4.2 25000 -25.3 -13.5 235 45 23 8.1 4.4 | -25.3 -13.5 230 49 25 7.6 4.2 24000 -23.0 -9.4 235 45 23 7.6 4.1 | -23.1 -9.6 230 47 24 7.4 4.1 23000 -20.7 -5.3 240 43 22 7.5 4.1 | -20.9 -5.6 225 43 22 7.4 4.1 22000 -18.5 -1.3 240 41 21 7.6 4.1 | -18.7 -1.7 220 40 21 7.4 4.1 21000 -16.4 2.5 240 39 20 5.3 2.9 | -16.5 2.3 220 37 19 6.7 3.6 20000 -14.8 5.4 240 37 19 5.6 3.1 | -14.6 5.7 220 35 18 6.8 3.7 19500 -14.0 6.8 240 36 18 5.6 3.1 | -13.6 7.5 215 34 17 6.8 3.7 19000 -13.2 8.2 240 35 18 5.6 3.1 | -12.6 9.3 215 33 17 6.8 3.7 18500 -12.3 9.9 240 34 18 6.6 3.6 | -11.6 11.1 215 32 16 6.6 3.6 18000 -11.3 11.7 240 36 18 7.0 3.8 | -10.6 12.9 215 32 17 6.6 3.6 17500 -10.3 13.5 235 37 19 7.0 3.8 | -9.6 14.7 215 33 17 6.6 3.6 17000 -9.3 15.3 235 37 19 6.0 3.3 | -8.7 16.3 215 34 18 6.3 3.5 16500 -8.4 16.9 235 37 19 6.1 3.3 | -7.8 18.0 210 36 18 6.2 3.4 16000 -7.4 18.7 230 37 19 6.9 3.8 | -6.8 19.8 210 37 19 7.5 4.1 15500 -6.4 20.5 230 35 18 7.1 3.9 | -5.6 21.9 205 36 19 7.8 4.3 15000 -4.7 23.5 225 33 17 8.3 4.5 | -4.5 23.9 205 36 19 8.5 4.7 14500 -3.5 25.7 220 32 17 8.2 4.5 | -3.1 26.4 205 36 18 9.7 5.3 14000 -2.3 27.9 215 31 16 8.8 4.9 | -0.9 30.4 200 35 18 9.4 5.2 13500 -0.9 30.4 210 31 16 9.1 5.0 | 0.5 32.9 200 34 18 9.4 5.1 13000 0.4 32.7 205 30 15 9.3 5.1 | 1.8 35.2 200 34 18 9.5 5.2 12500 1.8 35.2 205 30 15 9.5 5.2 | 3.3 37.9 200 34 17 9.6 5.3 12000 3.2 37.8 200 29 15 9.6 5.3 | 4.7 40.5 200 33 17 9.5 5.2 11500 4.7 40.5 200 29 15 9.8 5.4 | 6.1 43.0 195 33 17 9.3 5.1 11000 6.1 43.0 200 29 15 9.3 5.1 | 7.4 45.3 195 33 17 9.0 5.0 10500 7.4 45.3 200 29 15 8.2 4.5 | 8.7 47.7 190 32 17 8.2 4.5 10250 8.1 46.6 200 29 15 10.6 5.8 | 9.4 48.9 190 32 16 10.5 5.7 10000 8.9 48.0 200 29 15 11.3 6.2 | 10.2 50.4 190 32 16 11.1 6.1 9750 9.7 49.5 195 28 15 9.4 5.2 | 10.9 51.6 190 31 16 9.3 5.1 9500 10.4 50.7 195 28 15 9.2 5.1 | 11.6 52.9 185 31 16 8.7 4.8 9250 11.1 52.0 195 28 15 10.0 5.5 | 12.3 54.1 185 31 16 9.8 5.4 9000 11.9 53.4 195 28 14 10.6 5.8 | 13.1 55.6 185 31 16 10.6 5.8 8750 12.6 54.7 195 28 14 9.8 5.4 | 13.8 56.8 185 30 16 9.5 5.2 8500 13.4 56.1 195 28 14 9.7 5.3 | 14.5 58.1 185 30 15 9.2 5.0 8250 14.1 57.4 195 28 14 9.7 5.3 | 15.2 59.4 185 30 15 8.9 4.9 8000 14.8 58.6 195 27 14 8.8 4.8 | 15.9 60.6 180 30 15 10.3 5.7 7750 15.4 59.7 195 27 14 9.4 5.1 | 16.7 62.1 180 29 15 10.6 5.8 7500 16.2 61.2 190 27 14 10.4 5.7 | 17.4 63.3 180 28 15 9.3 5.1 7250 17.0 62.6 190 27 14 9.7 5.3 | 18.1 64.6 180 28 14 9.7 5.3 7000 17.6 63.7 190 27 14 8.6 4.7 | 18.8 65.8 180 28 14 7.5 4.1 6750 18.3 64.9 190 26 14 9.8 5.4 | 19.3 66.7 175 27 14 8.8 4.8 6500 19.1 66.4 190 26 13 11.4 6.2 | 20.1 68.2 175 26 13 11.5 6.3 6250 19.9 67.8 190 25 13 10.4 5.7 | 20.9 69.6 175 25 13 10.1 5.6 6000 20.7 69.3 190 24 13 9.6 5.2 | 21.6 70.9 175 24 12 8.1 4.4 5750 21.4 70.5 185 23 12 10.5 5.8 | 22.1 71.8 175 22 12 8.3 4.6 5500 22.3 72.1 185 20 11 16.9 9.3 | 22.8 73.0 170 19 10 11.5 6.3 ________________________________________________________________________________ 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