Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
487 UXUS97 KPUB 011210 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0610 MDT Saturday, June 1, 2024 This forecast is for Villa Grove, CO for Saturday, June 1, 2024: If the trigger temperature of 59.2 F/15.1 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 2058 ft/min (10.5 m/s) Maximum height of thermals.................. 28832 ft MSL (19830 ft AGL) Forecast maximum temperature................... 74.0 F/23.8 C Time of trigger temperature.................... 0900 MDT Time of overdevelopment........................ None Middle/high clouds during soaring window....... None Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 23608 ft MSL (14606 ft AGL) Thermal soaring outlook for Sunday 06/02....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:41:36 / 20:21:31 MDT Total possible sunshine........... 14 hr 39 min 55 sec (879 min 55 sec) Altitude of sun at 13:01:34 MDT... 73.93 degrees Upper air data from numerical model forecast valid on 06/01/2024 at 0600 MDT Freezing level.................. 14416 ft MSL (5414 ft AGL) Convective condensation level... 16247 ft MSL (7245 ft AGL) Lifted condensation level....... 18935 ft MSL (9934 ft AGL) Lifted index.................... -8.8 K index......................... +20.3 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 -57.0 -70.6 270 32 16 0.1 0.0 M M M M M 45000 -57.0 -70.6 270 39 20 -0.3 -0.2 M M M M M 40000 -57.5 -71.5 275 44 23 -1.0 -0.5 M M M M M 38000 -54.6 -66.3 280 42 22 5.6 3.1 M M M M M 36000 -51.2 -60.2 285 40 21 5.6 3.1 M M M M M 34000 -47.1 -52.8 285 38 20 6.6 3.6 M M M M M 32000 -43.1 -45.6 280 38 19 6.6 3.6 M M M M M 30000 -39.0 -38.2 275 37 19 7.1 3.9 24.5 76.1 0.9 M M 29000 -36.9 -34.4 275 37 19 7.1 3.9 23.5 74.2 0.1 M M 28000 -34.8 -30.6 270 36 19 7.0 3.9 22.6 72.6 -0.6 1978 10.0 27000 -32.5 -26.5 270 35 18 8.2 4.5 21.8 71.3 -1.3 1878 9.5 26000 -30.0 -22.0 270 34 18 8.2 4.5 21.2 70.2 -1.8 1775 9.0 25000 -27.5 -17.5 270 33 17 8.2 4.5 20.7 69.3 -2.2 1671 8.5 24000 -25.1 -13.2 270 32 17 8.2 4.5 20.2 68.3 -2.7 1569 8.0 23000 -22.7 -8.9 270 33 17 8.2 4.5 19.6 67.2 -3.3 1466 7.4 22000 -20.2 -4.4 270 33 17 8.2 4.5 19.1 66.3 -3.8 1364 6.9 21000 -17.7 0.1 270 33 17 8.6 4.7 18.6 65.5 -4.3 1259 6.4 20000 -15.2 4.6 275 33 17 8.6 4.7 18.2 64.8 -4.8 1153 5.9 19500 -13.9 7.0 275 33 17 8.6 4.7 18.0 64.5 -5.0 1100 5.6 19000 -12.6 9.3 275 33 17 8.8 4.8 17.9 64.2 -5.1 1047 5.3 18500 -11.3 11.7 275 32 17 8.9 4.9 17.7 63.9 -5.3 993 5.0 18000 -10.0 14.0 275 32 16 9.0 4.9 17.6 63.7 -5.5 938 4.8 17500 -8.0 17.6 275 30 15 9.0 4.9 17.4 63.3 -5.7 856 4.4 17000 -6.7 19.9 275 28 14 9.0 4.9 17.3 63.1 -5.9 802 4.1 16500 -5.3 22.5 275 26 13 9.2 5.0 17.2 62.9 -6.1 747 3.8 16000 -4.0 24.8 275 24 12 9.2 5.0 17.1 62.7 -6.2 691 3.5 15500 -2.6 27.3 275 21 11 9.0 5.0 17.0 62.6 -6.3 636 3.2 15000 -1.3 29.7 275 18 9 9.0 5.0 16.9 62.4 -6.5 581 3.0 14500 -0.0 32.0 275 15 8 8.0 4.4 16.7 62.1 -6.7 528 2.7 14000 1.1 34.0 270 12 6 7.9 4.3 16.4 61.5 -7.1 480 2.4 13500 2.2 36.0 270 8 4 7.5 4.1 16.1 61.0 -7.5 432 2.2 13000 3.3 37.9 260 6 3 7.8 4.3 15.7 60.3 -7.9 385 2.0 12500 4.4 39.9 235 4 2 7.8 4.3 15.4 59.8 -8.3 336 1.7 12000 5.5 41.9 210 5 2 7.5 4.1 15.1 59.1 -8.7 289 1.5 11750 6.1 43.0 200 5 3 8.2 4.5 14.9 58.9 -8.9 264 1.3 11500 6.7 44.1 195 5 3 8.2 4.5 14.8 58.6 -9.1 238 1.2 11250 7.2 45.0 185 6 3 6.9 3.8 14.7 58.4 -9.2 214 1.1 11000 7.7 45.9 180 6 3 5.9 3.3 14.4 57.9 -9.6 194 1.0 10750 8.1 46.6 175 7 3 6.1 3.3 14.1 57.4 -9.9 173 0.9 10500 8.5 47.3 175 7 4 6.5 3.6 13.8 56.9 -10.3 155 0.8 10250 8.7 47.7 170 7 4 -1.2 -0.7 13.4 56.1 -10.8 140 0.7 10000 8.2 46.8 175 6 3 -7.2 -4.0 12.2 54.0 -12.1 148 0.8 9750 7.7 45.9 180 4 2 -6.0 -3.3 11.0 51.8 -13.4 156 0.8 9500 7.0 44.6 195 3 1 -9.6 -5.3 9.7 49.5 -14.8 168 0.9 9250 6.2 43.2 260 2 1 -10.8 -5.9 8.1 46.7 -16.4 186 0.9 9000 M M M M M M M M M M M M 8750 M M M M M M M M M M M M 8500 M M M M M M M M M M M M 8250 M M M M M M M M M M M M 8000 M M M M M M M M M M M M * * * * * * Numerical weather prediction model forecast data valid * * * * * * 06/01/2024 at 0900 MDT | 06/01/2024 at 1200 MDT | CAPE... +544.9 LI... -2.5 | CAPE... +327.7 LI... -1.6 CINH... -41.4 K Index... +18.5 | CINH... -0.5 K Index... +22.7 | 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 -57.7 -71.9 270 33 17 -0.1 -0.0 | -57.8 -72.0 270 35 18 -0.4 -0.2 45000 -58.0 -72.4 270 39 20 -0.8 -0.4 | -58.6 -73.5 270 47 24 -1.2 -0.6 40000 -59.2 -74.6 275 42 21 1.9 1.1 | -60.4 -76.7 275 47 24 2.4 1.3 38000 -55.2 -67.4 280 39 20 6.9 3.8 | -55.9 -68.6 275 44 23 7.7 4.2 36000 -51.1 -60.0 285 37 19 6.9 3.8 | -51.3 -60.3 270 42 21 7.7 4.2 34000 -46.6 -51.9 285 34 17 7.8 4.3 | -46.5 -51.7 270 39 20 8.3 4.6 32000 -41.9 -43.4 285 31 16 7.8 4.3 | -41.6 -42.9 270 37 19 8.3 4.6 30000 -37.5 -35.5 285 31 16 7.1 3.9 | -37.0 -34.6 270 36 18 7.1 3.9 29000 -35.4 -31.7 285 32 16 7.1 3.9 | -34.9 -30.8 270 35 18 7.1 3.9 28000 -33.3 -27.9 280 33 17 7.1 3.9 | -32.2 -26.0 270 34 17 7.1 3.9 27000 -30.7 -23.3 280 33 17 6.9 3.8 | -30.1 -22.2 270 34 18 7.2 4.0 26000 -28.7 -19.7 275 33 17 6.9 3.8 | -27.9 -18.2 270 35 18 7.2 4.0 25000 -26.6 -15.9 270 33 17 6.9 3.8 | -25.7 -14.3 270 35 18 7.2 4.0 24000 -24.4 -11.9 270 32 16 7.6 4.2 | -23.7 -10.7 270 35 18 6.8 3.7 23000 -22.1 -7.8 270 31 16 7.7 4.2 | -21.7 -7.1 270 35 18 6.8 3.7 22000 -19.9 -3.8 275 30 16 7.7 4.2 | -19.7 -3.5 275 35 18 6.7 3.7 21000 -17.5 0.5 275 30 15 8.1 4.4 | -17.3 0.9 275 33 17 8.6 4.7 20000 -15.2 4.6 275 29 15 8.2 4.5 | -14.8 5.4 275 30 15 8.7 4.8 19500 -14.0 6.8 275 28 15 8.2 4.5 | -13.5 7.7 275 29 15 8.8 4.8 19000 -12.8 9.0 275 28 14 8.9 4.9 | -12.3 9.9 275 27 14 8.9 4.9 18500 -11.4 11.5 280 27 14 9.3 5.1 | -10.9 12.4 270 24 12 9.0 5.0 18000 -10.0 14.0 280 26 13 9.4 5.1 | -9.6 14.7 270 21 11 9.0 5.0 17500 -8.6 16.5 280 24 12 9.2 5.0 | -8.3 17.1 270 19 10 9.3 5.1 17000 -7.3 18.9 280 23 12 9.2 5.0 | -6.9 19.6 265 16 8 9.3 5.1 16500 -5.9 21.4 280 22 11 9.2 5.1 | -5.5 22.1 260 13 7 9.3 5.1 16000 -4.5 23.9 280 21 11 9.2 5.1 | -4.2 24.4 260 12 6 9.4 5.1 15500 -3.1 26.4 280 20 10 9.3 5.1 | -2.8 27.0 255 11 6 9.6 5.2 15000 -1.8 28.8 280 19 10 9.3 5.1 | -1.3 29.7 255 10 5 9.9 5.4 14500 -0.4 31.3 280 18 9 9.1 5.0 | 0.8 33.4 250 10 5 9.0 4.9 14000 1.5 34.7 275 16 8 8.7 4.8 | 2.3 36.1 250 9 5 9.7 5.3 13500 2.8 37.0 270 14 7 8.3 4.6 | 3.8 38.8 250 9 5 8.5 4.7 13000 4.0 39.2 265 13 7 8.2 4.5 | 5.1 41.2 245 9 5 11.0 6.1 12500 5.1 41.2 255 12 6 7.9 4.4 | 6.7 44.1 245 9 4 10.1 5.5 12000 6.1 43.0 250 11 6 6.8 3.7 | 7.9 46.2 245 8 4 9.2 5.0 11750 6.7 44.1 245 11 6 7.3 4.0 | 8.8 47.8 245 8 4 11.5 6.3 11500 7.2 45.0 240 11 6 7.0 3.9 | 9.6 49.3 245 8 4 10.8 5.9 11250 7.6 45.7 240 11 5 6.2 3.4 | 10.4 50.7 240 8 4 10.2 5.6 11000 8.1 46.6 240 10 5 5.6 3.1 | 11.1 52.0 240 8 4 9.7 5.3 10750 8.5 47.3 240 10 5 6.1 3.4 | 11.8 53.2 240 8 4 10.1 5.6 10500 8.9 48.0 240 10 5 6.8 3.7 | 12.6 54.7 240 8 4 10.4 5.7 10250 9.4 48.9 235 9 5 8.1 4.4 | 13.4 56.1 240 7 4 10.5 5.8 10000 10.0 50.0 235 8 4 9.0 4.9 | 14.2 57.6 240 7 4 10.9 6.0 9750 10.6 51.1 235 7 4 8.4 4.6 | 15.0 59.0 240 7 4 10.1 5.5 9500 11.2 52.2 235 6 3 11.9 6.5 | 15.8 60.4 235 7 3 13.3 7.3 9250 12.4 54.3 235 5 3 21.4 11.8 | 17.2 63.0 235 6 3 26.6 14.6 9000 14.1 57.4 245 4 2 22.7 12.5 | 19.7 67.5 235 6 3 41.3 22.7 8750 M M M M M M M | M M M M M M M 8500 M M M M M M M | M M M M M M M 8250 M M M M M M M | M M M M M M M 8000 M M M M M M M | M M M M M M M 06/01/2024 at 1500 MDT | 06/01/2024 at 1800 MDT | CAPE... +89.6 LI... -0.4 | CAPE... +402.2 LI... -1.4 CINH... -5.5 K Index... +24.6 | CINH... -20.3 K Index... +22.5 | 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 -58.4 -73.1 270 42 22 -0.3 -0.2 | -58.9 -74.0 270 35 18 0.2 0.1 45000 -58.8 -73.8 275 51 26 -0.1 -0.0 | -58.6 -73.5 275 47 24 0.3 0.2 40000 -58.9 -74.0 280 63 32 3.0 1.6 | -58.1 -72.6 275 61 31 3.9 2.1 38000 -55.3 -67.5 275 57 29 6.0 3.3 | -54.2 -65.6 280 56 29 6.5 3.6 36000 -51.8 -61.2 275 52 27 6.0 3.3 | -50.2 -58.4 285 51 26 6.5 3.6 34000 -47.1 -52.8 270 46 24 8.8 4.8 | -46.0 -50.8 285 48 25 7.4 4.1 32000 -41.8 -43.2 260 40 20 8.8 4.8 | -41.6 -42.9 280 45 23 7.4 4.0 30000 -36.7 -34.1 260 33 17 8.5 4.7 | -36.0 -32.8 275 38 20 8.7 4.8 29000 -34.1 -29.4 260 30 15 8.6 4.7 | -33.4 -28.1 275 34 18 8.7 4.8 28000 -30.9 -23.6 265 26 13 8.5 4.7 | -30.8 -23.4 270 30 16 8.7 4.8 27000 -28.5 -19.3 265 23 12 8.2 4.5 | -28.4 -19.1 265 29 15 8.1 4.4 26000 -26.1 -15.0 265 19 10 8.2 4.5 | -26.0 -14.8 265 29 15 8.1 4.4 25000 -23.6 -10.5 270 16 8 8.3 4.5 | -23.6 -10.5 265 28 14 8.2 4.5 24000 -21.4 -6.5 270 13 7 7.4 4.1 | -21.4 -6.5 265 27 14 7.2 4.0 23000 -19.2 -2.6 265 10 5 7.4 4.1 | -19.2 -2.6 255 27 14 7.2 4.0 22000 -17.0 1.4 260 8 4 7.5 4.1 | -17.1 1.2 250 27 14 7.2 4.0 21000 -15.0 5.0 255 7 4 6.9 3.8 | -14.9 5.2 245 27 14 7.4 4.1 20000 -12.9 8.8 245 7 4 7.0 3.8 | -12.7 9.1 240 27 14 7.4 4.1 19500 -11.9 10.6 240 7 4 7.0 3.8 | -11.7 10.9 240 28 14 7.4 4.1 19000 -10.9 12.4 235 7 4 6.8 3.7 | -10.6 12.9 235 28 14 7.8 4.3 18500 -9.9 14.2 230 8 4 6.7 3.7 | -9.4 15.1 235 27 14 8.0 4.4 18000 -8.9 16.0 225 8 4 6.8 3.7 | -8.2 17.2 235 26 14 8.0 4.4 17500 -7.9 17.8 225 9 4 7.4 4.0 | -7.0 19.4 235 26 13 8.8 4.8 17000 -6.8 19.8 225 9 5 7.3 4.0 | -5.7 21.7 235 25 13 8.7 4.8 16500 -5.8 21.6 225 10 5 7.9 4.3 | -4.4 24.1 235 24 12 8.8 4.8 16000 -4.6 23.7 225 10 5 8.0 4.4 | -3.1 26.4 235 23 12 8.8 4.8 15500 -3.4 25.9 225 11 6 8.5 4.6 | -1.8 28.8 235 22 12 9.0 5.0 15000 -2.0 28.4 230 11 6 9.3 5.1 | -0.4 31.3 235 21 11 9.6 5.3 14500 -0.6 30.9 230 12 6 8.8 4.8 | 1.5 34.7 235 20 10 6.9 3.8 14000 0.7 33.3 230 13 7 9.8 5.4 | 2.8 37.0 235 19 10 9.1 5.0 13500 2.2 36.0 230 13 7 10.2 5.6 | 4.2 39.6 240 19 10 8.3 4.6 13000 4.1 39.4 230 14 7 11.1 6.1 | 5.4 41.7 240 18 9 9.1 5.0 12500 5.7 42.3 230 15 8 9.7 5.3 | 6.8 44.2 240 18 9 8.8 4.8 12000 6.8 44.2 230 15 8 8.6 4.7 | 7.8 46.0 245 17 9 7.7 4.2 11750 7.6 45.7 230 16 8 12.2 6.7 | 8.5 47.3 245 17 9 9.9 5.4 11500 8.4 47.1 230 16 8 10.8 5.9 | 9.2 48.6 245 17 9 9.3 5.1 11250 9.2 48.6 230 16 8 9.5 5.2 | 9.9 49.8 250 17 9 8.6 4.7 11000 9.9 49.8 230 16 8 8.5 4.7 | 10.4 50.7 250 17 9 7.7 4.2 10750 10.5 50.9 230 17 9 10.2 5.6 | 11.0 51.8 255 16 8 8.7 4.8 10500 11.4 52.5 230 17 9 11.2 6.1 | 11.7 53.1 255 16 8 9.3 5.1 10250 12.1 53.8 230 17 9 10.0 5.5 | 12.4 54.3 255 15 8 9.5 5.2 10000 12.9 55.2 230 17 9 9.7 5.3 | 13.1 55.6 255 15 8 9.8 5.4 9750 13.6 56.5 230 17 9 9.7 5.3 | 13.8 56.8 260 14 7 9.8 5.4 9500 14.4 57.9 230 16 8 11.8 6.5 | 14.5 58.1 260 13 7 10.9 6.0 9250 15.4 59.7 230 15 8 16.9 9.3 | 15.4 59.7 260 11 6 14.5 7.9 9000 16.7 62.1 230 13 7 15.3 8.4 | 16.7 62.1 260 8 4 21.5 11.8 8750 M M M M M M M | M M M M M M M 8500 M M M M M M M | M M M M M M M 8250 M M M M M M M | M M M M M M M 8000 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 Villa Grove, Colorado at: North Latitude: 38 deg 16 min 03 sec West Longitude: 105 deg 53 min 37 sec Elevation: 7986 feet (2434 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