Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
956 UXUS97 KPUB 151209 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0608 MDT Thursday, August 15, 2024 This forecast is for Villa Grove, CO for Thursday, August 15, 2024: If the trigger temperature of 64.4 F/18.0 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 983 ft/min (5.0 m/s) Maximum height of thermals.................. 19965 ft MSL (10990 ft AGL) Forecast maximum temperature................... 80.0 F/27.1 C Time of trigger temperature.................... 0930 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................. 18362 ft MSL (9387 ft AGL) Thermal soaring outlook for Friday 08/16....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:19:05 / 19:56:45 MDT Total possible sunshine........... 13 hr 37 min 41 sec (817 min 41 sec) Altitude of sun at 13:07:55 MDT... 65.38 degrees Upper air data from numerical model forecast valid on 08/15/2024 at 0600 MDT Freezing level.................. 15475 ft MSL (6500 ft AGL) Convective condensation level... 16700 ft MSL (7725 ft AGL) Lifted condensation level....... 19327 ft MSL (10351 ft AGL) Lifted index.................... -2.9 K index......................... -1.4 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 -63.8 -82.8 285 28 15 1.4 0.7 M M M M M 45000 -59.2 -74.6 280 41 21 6.1 3.4 M M M M M 40000 -49.9 -57.8 285 49 25 6.5 3.5 M M M M M 38000 -46.0 -50.8 280 48 25 6.5 3.5 M M M M M 36000 -42.1 -43.8 280 47 24 6.5 3.6 M M M M M 34000 -37.2 -35.0 285 46 24 7.3 4.0 M M M M M 32000 -32.8 -27.0 290 46 24 7.3 4.0 M M M M M 30000 -28.6 -19.5 290 44 23 7.0 3.8 35.8 96.4 7.2 M M 29000 -26.5 -15.7 290 43 22 7.0 3.8 34.8 94.7 6.5 M M 28000 -24.4 -11.9 290 42 22 7.2 3.9 33.9 93.0 5.9 M M 27000 -22.2 -8.0 290 42 22 7.2 3.9 32.8 91.1 5.1 M M 26000 -20.1 -4.2 290 43 22 7.2 3.9 31.9 89.4 4.3 M M 25000 -17.9 -0.2 290 43 22 7.6 4.2 31.1 88.0 3.7 M M 24000 -15.4 4.3 290 43 22 8.5 4.6 30.5 86.9 3.3 M M 23000 -12.9 8.8 295 43 22 8.5 4.7 30.1 86.1 2.9 M M 22000 -10.3 13.5 295 44 22 7.2 4.0 29.7 85.5 2.7 M M 21000 -8.6 16.5 290 38 20 5.6 3.1 28.2 82.8 1.4 M M 20000 -6.9 19.6 290 33 17 5.7 3.1 26.8 80.3 0.1 M M 19500 -6.1 21.0 290 30 15 6.1 3.4 26.2 79.2 -0.5 952 4.8 19000 -5.5 22.1 290 27 14 2.2 1.2 25.3 77.5 -1.3 920 4.7 18500 -5.2 22.6 290 24 12 2.8 1.6 24.1 75.4 -2.5 894 4.5 18000 -4.8 23.4 290 21 11 3.7 2.0 23.0 73.4 -3.6 869 4.4 17500 -4.2 24.4 295 18 9 4.6 2.5 22.1 71.8 -4.5 836 4.2 17000 -3.6 25.5 300 16 8 4.4 2.4 21.3 70.3 -5.4 802 4.1 16500 -2.7 27.1 305 14 7 8.0 4.4 20.7 69.2 -6.0 761 3.9 16000 -1.0 30.2 315 12 6 7.7 4.2 20.2 68.3 -6.5 687 3.5 15500 0.2 32.4 315 11 6 8.2 4.5 19.9 67.8 -6.8 637 3.2 15000 1.4 34.5 315 11 6 8.3 4.5 19.6 67.3 -7.1 586 3.0 14500 2.6 36.7 310 11 5 7.8 4.3 19.3 66.8 -7.5 537 2.7 14000 3.8 38.8 310 11 6 8.4 4.6 19.1 66.4 -7.7 485 2.5 13500 5.0 41.0 305 11 6 9.3 5.1 18.9 66.1 -8.0 434 2.2 13000 6.2 43.2 310 11 6 7.0 3.9 18.7 65.6 -8.4 384 2.0 12500 7.2 45.0 310 11 6 7.9 4.3 18.3 65.0 -8.9 340 1.7 12000 8.3 46.9 315 11 5 8.1 4.4 18.1 64.6 -9.3 290 1.5 11750 8.9 48.0 315 10 5 7.9 4.3 17.9 64.3 -9.5 266 1.4 11500 9.4 48.9 320 10 5 7.2 3.9 17.8 64.0 -9.7 243 1.2 11250 9.9 49.8 320 9 5 6.6 3.6 17.6 63.6 -10.0 221 1.1 11000 10.4 50.7 325 8 4 6.2 3.4 17.3 63.2 -10.2 199 1.0 10750 10.8 51.4 330 8 4 8.5 4.7 17.1 62.8 -10.5 178 0.9 10500 11.5 52.7 335 7 4 6.1 3.4 17.0 62.6 -10.6 152 0.8 10250 11.7 53.1 340 6 3 2.3 1.3 16.5 61.7 -11.2 138 0.7 10000 11.9 53.4 345 6 3 1.8 1.0 16.0 60.7 -11.8 125 0.6 9750 12.0 53.6 345 5 3 6.8 3.7 15.4 59.8 -12.4 112 0.6 9500 12.5 54.5 350 4 2 -2.5 -1.4 15.2 59.3 -12.7 92 0.5 9250 11.1 52.0 335 3 2 -33.3 -18.3 13.0 55.5 -14.8 126 0.6 9000 9.7 49.5 305 3 1 26.0 14.3 10.9 51.7 -17.0 160 0.8 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 * * * * * * 08/15/2024 at 0900 MDT | 08/15/2024 at 1200 MDT | CAPE... +64.2 LI... +0.7 | CAPE... +23.2 LI... +0.9 CINH... -28.9 K Index... -8.2 | CINH... 0.0 K Index... +2.4 | 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 -63.6 -82.5 280 24 12 1.6 0.9 | -63.4 -82.1 265 23 12 1.8 1.0 45000 -58.9 -74.0 275 38 20 6.1 3.4 | -58.5 -73.3 265 37 19 6.0 3.3 40000 -49.3 -56.7 275 47 24 6.1 3.4 | -49.1 -56.4 265 43 22 6.1 3.4 38000 -45.6 -50.1 280 45 23 6.1 3.4 | -45.4 -49.7 270 42 21 6.1 3.4 36000 -41.9 -43.4 280 44 23 6.4 3.5 | -41.7 -43.1 275 40 21 6.4 3.5 34000 -37.8 -36.0 285 43 22 6.9 3.8 | -37.7 -35.9 280 38 20 6.8 3.7 32000 -33.7 -28.7 290 42 21 7.0 3.8 | -33.6 -28.5 285 37 19 6.8 3.7 30000 -29.3 -20.7 290 39 20 7.3 4.0 | -29.3 -20.7 285 35 18 7.4 4.0 29000 -27.2 -17.0 285 38 19 7.3 4.0 | -26.5 -15.7 280 33 17 7.4 4.0 28000 -25.0 -13.0 285 36 19 7.2 4.0 | -24.3 -11.7 280 33 17 7.3 4.0 27000 -22.3 -8.1 285 37 19 7.2 4.0 | -22.1 -7.8 280 33 17 7.3 4.0 26000 -20.1 -4.2 285 38 19 7.2 4.0 | -19.9 -3.8 280 33 17 7.3 4.0 25000 -18.0 -0.4 285 38 20 7.3 4.0 | -17.7 0.1 280 33 17 7.2 4.0 24000 -15.7 3.7 285 38 20 7.4 4.1 | -15.6 3.9 280 33 17 7.1 3.9 23000 -13.5 7.7 285 38 19 7.4 4.1 | -13.5 7.7 285 34 17 7.1 3.9 22000 -11.3 11.7 285 38 19 6.7 3.7 | -11.4 11.5 285 34 18 6.5 3.6 21000 -9.4 15.1 285 35 18 6.4 3.5 | -9.5 14.9 280 33 17 6.2 3.4 20000 -7.5 18.5 290 33 17 6.4 3.5 | -7.7 18.1 280 31 16 6.2 3.4 19500 -6.5 20.3 290 32 16 6.1 3.3 | -6.7 19.9 280 31 16 5.8 3.2 19000 -5.9 21.4 290 29 15 2.9 1.6 | -6.1 21.0 280 28 15 3.1 1.7 18500 -5.5 22.1 295 26 13 3.3 1.8 | -5.7 21.7 280 26 13 3.3 1.8 18000 -5.0 23.0 295 23 12 4.9 2.7 | -5.2 22.6 285 23 12 5.0 2.7 17500 -4.2 24.4 295 21 11 5.6 3.1 | -4.4 24.1 285 21 11 5.7 3.1 17000 -3.5 25.7 295 18 9 5.9 3.2 | -3.6 25.5 290 19 10 6.3 3.4 16500 -2.6 27.3 295 16 8 6.9 3.8 | -2.7 27.1 290 17 9 8.0 4.4 16000 -1.6 29.1 290 13 7 6.8 3.7 | -1.6 29.1 290 14 7 8.0 4.4 15500 -0.5 31.1 285 10 5 8.3 4.5 | -0.4 31.3 285 12 6 9.3 5.1 15000 0.7 33.3 290 8 4 8.3 4.6 | 0.9 33.6 275 10 5 9.4 5.1 14500 2.0 35.6 300 6 3 6.5 3.6 | 2.9 37.2 265 9 4 9.5 5.2 14000 3.7 38.7 315 6 3 8.6 4.7 | 4.4 39.9 260 8 4 9.9 5.4 13500 5.0 41.0 325 6 3 9.9 5.4 | 6.0 42.8 260 8 4 11.3 6.2 13000 6.3 43.3 330 6 3 7.9 4.3 | 7.4 45.3 255 7 4 8.5 4.7 12500 7.5 45.5 330 6 3 8.3 4.6 | 8.8 47.8 255 7 3 10.3 5.6 12000 8.6 47.5 325 5 3 8.3 4.6 | 10.4 50.7 255 6 3 9.6 5.3 11750 9.2 48.6 325 5 3 8.2 4.5 | 11.0 51.8 255 6 3 8.4 4.6 11500 9.8 49.6 320 5 3 8.2 4.5 | 11.7 53.1 255 6 3 9.6 5.3 11250 10.3 50.5 310 5 3 8.2 4.5 | 12.5 54.5 255 6 3 10.1 5.6 11000 10.9 51.6 305 6 3 8.1 4.4 | 13.2 55.8 250 6 3 10.0 5.5 10750 11.4 52.5 300 6 3 8.8 4.8 | 14.0 57.2 250 6 3 10.2 5.6 10500 12.0 53.6 295 6 3 8.2 4.5 | 14.7 58.5 250 5 3 10.9 6.0 10250 12.6 54.7 290 6 3 7.2 4.0 | 15.6 60.1 250 5 3 11.1 6.1 10000 13.1 55.6 285 5 3 7.4 4.1 | 16.4 61.5 250 5 3 11.4 6.3 9750 13.6 56.5 280 5 3 7.7 4.2 | 17.2 63.0 250 5 2 9.8 5.3 9500 14.2 57.6 275 5 2 11.5 6.3 | 18.0 64.4 250 5 2 15.7 8.6 9250 15.2 59.4 270 4 2 16.6 9.1 | 19.7 67.5 250 4 2 30.6 16.8 9000 16.2 61.2 265 3 2 7.9 4.3 | 21.4 70.5 250 4 2 2.9 1.6 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 08/15/2024 at 1500 MDT | 08/15/2024 at 1800 MDT | CAPE... +147.8 LI... -1.3 | CAPE... +280.4 LI... -1.4 CINH... -0.4 K Index... +23.6 | CINH... -15.5 K Index... +26.7 | 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 -63.4 -82.1 275 17 9 1.9 1.1 | -62.9 -81.2 280 15 8 2.0 1.1 45000 -58.7 -73.7 275 30 15 5.3 2.9 | -58.2 -72.8 280 28 14 5.3 2.9 40000 -50.0 -58.0 265 43 22 6.8 3.7 | -49.5 -57.1 275 49 25 6.5 3.5 38000 -45.9 -50.6 265 42 22 6.8 3.7 | -45.6 -50.1 270 49 25 6.5 3.5 36000 -41.8 -43.2 265 42 21 6.9 3.8 | -41.8 -43.2 270 49 25 6.5 3.6 34000 -37.6 -35.7 270 39 20 7.0 3.8 | -37.8 -36.0 275 46 24 6.7 3.7 32000 -33.4 -28.1 280 37 19 7.1 3.9 | -33.8 -28.8 285 44 23 6.7 3.7 30000 -29.1 -20.4 280 33 17 7.2 3.9 | -29.5 -21.1 285 39 20 7.3 4.0 29000 -27.0 -16.6 280 31 16 7.2 3.9 | -26.7 -16.1 280 35 18 7.3 4.0 28000 -24.3 -11.7 280 30 15 7.2 4.0 | -24.5 -12.1 280 33 17 7.6 4.2 27000 -22.1 -7.8 280 30 15 7.2 4.0 | -22.2 -8.0 275 32 16 7.6 4.2 26000 -20.0 -4.0 275 30 15 7.2 4.0 | -19.9 -3.8 275 31 16 7.6 4.2 25000 -17.8 -0.0 275 30 15 7.2 4.0 | -17.7 0.1 270 30 15 7.3 4.0 24000 -15.7 3.7 275 31 16 7.2 4.0 | -15.5 4.1 275 30 15 7.2 3.9 23000 -13.5 7.7 280 31 16 7.2 4.0 | -13.4 7.9 275 30 15 7.2 3.9 22000 -11.4 11.5 280 32 16 5.7 3.1 | -11.3 11.7 275 29 15 6.6 3.6 21000 -9.9 14.2 275 30 16 5.4 3.0 | -9.5 14.9 275 28 14 6.6 3.6 20000 -8.4 16.9 275 29 15 5.7 3.1 | -7.6 18.3 270 27 14 7.0 3.8 19500 -7.6 18.3 275 28 15 5.9 3.3 | -6.7 19.9 265 26 13 7.2 3.9 19000 -6.8 19.8 275 25 13 6.2 3.4 | -5.8 21.6 265 23 12 6.5 3.6 18500 -6.0 21.2 275 21 11 6.2 3.4 | -4.9 23.2 265 20 10 6.5 3.6 18000 -5.1 22.8 275 17 9 8.3 4.6 | -3.9 25.0 260 17 9 8.1 4.4 17500 -3.8 25.2 275 15 8 8.8 4.8 | -2.7 27.1 265 15 8 8.5 4.7 17000 -2.5 27.5 270 13 7 9.0 4.9 | -1.5 29.3 265 14 7 8.5 4.7 16500 -1.2 29.8 270 12 6 9.4 5.2 | -0.3 31.5 265 12 6 8.1 4.4 16000 0.2 32.4 265 11 5 9.4 5.1 | 0.9 33.6 265 11 6 8.1 4.5 15500 1.6 34.9 260 10 5 9.4 5.1 | 2.1 35.8 260 10 5 8.3 4.6 15000 3.0 37.4 255 10 5 9.4 5.2 | 4.0 39.2 260 9 5 8.3 4.6 14500 5.0 41.0 250 10 5 9.5 5.2 | 5.2 41.4 255 9 5 8.4 4.6 14000 6.5 43.7 250 10 5 9.6 5.3 | 6.5 43.7 250 10 5 8.4 4.6 13500 8.0 46.4 245 10 5 11.3 6.2 | 7.8 46.0 250 11 6 9.9 5.5 13000 9.5 49.1 245 9 5 8.7 4.8 | 9.1 48.4 240 12 6 8.1 4.4 12500 10.9 51.6 240 9 5 9.7 5.3 | 10.4 50.7 235 12 6 9.1 5.0 12000 12.3 54.1 240 9 5 9.9 5.4 | 11.7 53.1 230 13 7 9.0 5.0 11750 13.1 55.6 240 9 5 9.8 5.4 | 12.4 54.3 230 13 7 8.6 4.7 11500 13.8 56.8 235 9 5 9.7 5.3 | 13.0 55.4 230 13 7 9.2 5.0 11250 14.5 58.1 235 9 5 9.5 5.2 | 13.8 56.8 230 13 7 9.6 5.2 11000 15.2 59.4 235 9 5 9.6 5.2 | 14.5 58.1 225 13 7 9.4 5.2 10750 15.9 60.6 235 9 5 10.5 5.8 | 15.2 59.4 225 13 6 10.3 5.7 10500 16.8 62.2 235 9 5 10.9 6.0 | 16.0 60.8 225 13 6 10.8 5.9 10250 17.5 63.5 235 9 4 10.3 5.6 | 16.8 62.2 225 12 6 10.3 5.7 10000 18.3 64.9 230 8 4 10.8 5.9 | 17.5 63.5 225 12 6 10.8 5.9 9750 19.1 66.4 230 8 4 9.2 5.0 | 18.3 64.9 225 12 6 9.3 5.1 9500 19.9 67.8 230 8 4 15.5 8.5 | 19.0 66.2 220 12 6 11.8 6.5 9250 21.6 70.9 230 8 4 30.6 16.8 | 20.2 68.4 220 10 5 20.5 11.2 9000 23.3 73.9 230 7 4 2.6 1.5 | 21.4 70.5 220 9 4 4.0 2.2 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