Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
969 UXUS97 KPUB 171220 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0620 MDT Saturday, August 17, 2024 This forecast is for Villa Grove, CO for Saturday, August 17, 2024: If the trigger temperature of 72.4 F/22.5 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1515 ft/min (7.7 m/s) Maximum height of thermals.................. 24009 ft MSL (15026 ft AGL) Forecast maximum temperature................... 85.0 F/29.9 C Time of trigger temperature.................... 1030 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................. 20520 ft MSL (11538 ft AGL) Thermal soaring outlook for Sunday 08/18....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:20:50 / 19:54:08 MDT Total possible sunshine........... 13 hr 33 min 18 sec (813 min 18 sec) Altitude of sun at 13:07:29 MDT... 64.75 degrees Upper air data from numerical model forecast valid on 08/17/2024 at 0600 MDT Freezing level.................. 16749 ft MSL (7766 ft AGL) Convective condensation level... 18254 ft MSL (9271 ft AGL) Lifted condensation level....... 20486 ft MSL (11503 ft AGL) Lifted index.................... -4.1 K index......................... +8.4 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 -64.5 -84.1 250 19 10 2.3 1.3 M M M M M 45000 -59.5 -75.1 260 26 14 5.2 2.8 M M M M M 40000 -50.8 -59.4 265 35 18 7.1 3.9 M M M M M 38000 -46.6 -51.9 270 37 19 7.1 3.9 M M M M M 36000 -42.3 -44.1 270 40 20 7.7 4.2 M M M M M 34000 -37.5 -35.5 275 38 20 7.9 4.3 M M M M M 32000 -32.8 -27.0 280 37 19 8.0 4.4 M M M M M 30000 -28.3 -18.9 290 34 17 7.4 4.1 36.3 97.4 5.5 M M 29000 -25.5 -13.9 295 32 16 7.4 4.1 35.4 95.6 4.8 M M 28000 -23.5 -10.3 300 31 16 6.3 3.5 34.3 93.8 4.0 M M 27000 -21.6 -6.9 305 30 15 6.3 3.5 33.0 91.4 2.9 M M 26000 -19.7 -3.5 305 29 15 6.3 3.5 31.8 89.3 2.0 M M 25000 -17.8 -0.0 305 28 14 6.4 3.5 30.7 87.2 1.1 M M 24000 -15.9 3.4 310 24 12 6.4 3.5 29.4 84.9 -0.0 1512 7.7 23000 -14.0 6.8 310 20 10 6.4 3.5 28.2 82.8 -1.1 1425 7.2 22000 -12.0 10.4 310 17 9 7.7 4.2 27.2 81.0 -2.0 1337 6.8 21000 -9.7 14.5 290 13 7 7.8 4.3 26.5 79.6 -2.7 1238 6.3 20000 -7.4 18.7 265 11 6 7.8 4.3 25.8 78.5 -3.3 1139 5.8 19500 -6.3 20.7 250 11 6 7.5 4.1 25.6 78.0 -3.6 1090 5.5 19000 -5.3 22.5 245 12 6 6.9 3.8 25.1 77.2 -4.1 1046 5.3 18500 -4.3 24.3 240 14 7 7.1 3.9 24.6 76.4 -4.6 1003 5.1 18000 -3.3 26.1 235 15 8 8.2 4.5 24.3 75.7 -5.1 957 4.9 17500 -2.1 28.2 230 15 8 8.3 4.6 24.0 75.3 -5.4 907 4.6 17000 -1.0 30.2 225 15 8 8.8 4.8 23.8 74.9 -5.7 857 4.4 16500 0.4 32.7 225 15 8 9.6 5.3 23.8 74.8 -5.8 801 4.1 16000 1.8 35.2 220 15 8 9.7 5.3 23.7 74.7 -5.9 744 3.8 15500 3.3 37.9 220 14 7 9.2 5.1 23.7 74.7 -6.0 687 3.5 15000 5.4 41.7 215 12 6 9.2 5.1 23.6 74.5 -6.1 600 3.0 14500 6.8 44.2 210 11 6 8.8 4.9 23.5 74.2 -6.2 545 2.8 14000 8.1 46.6 210 10 5 8.8 4.8 23.3 74.0 -6.4 490 2.5 13500 9.5 49.1 215 8 4 10.6 5.8 23.3 74.0 -6.5 434 2.2 13000 10.7 51.3 215 8 4 7.7 4.2 23.2 73.7 -6.7 383 1.9 12500 11.8 53.2 225 7 4 8.0 4.4 22.9 73.3 -7.2 336 1.7 12000 12.9 55.2 235 6 3 7.9 4.3 22.7 72.8 -7.6 288 1.5 11750 13.4 56.1 240 6 3 7.5 4.1 22.5 72.5 -7.8 265 1.3 11500 13.9 57.0 245 6 3 6.8 3.7 22.3 72.2 -8.0 242 1.2 11250 14.4 57.9 250 7 3 6.4 3.5 22.1 71.7 -8.3 221 1.1 11000 14.8 58.6 250 7 4 6.4 3.5 21.8 71.3 -8.6 200 1.0 10750 15.3 59.5 255 7 4 7.4 4.1 21.6 70.8 -8.9 179 0.9 10500 15.8 60.4 255 7 4 4.2 2.3 21.3 70.4 -9.2 157 0.8 10250 15.9 60.6 255 7 4 1.5 0.8 20.7 69.3 -9.8 145 0.7 10000 16.0 60.8 260 8 4 0.8 0.4 20.1 68.2 -10.4 134 0.7 9750 16.2 61.2 260 8 4 6.2 3.4 19.5 67.2 -11.0 122 0.6 9500 16.5 61.7 255 8 4 -7.0 -3.8 19.1 66.5 -11.5 107 0.5 9250 14.6 58.3 260 6 3 -45.1 -24.8 16.4 61.5 -14.1 156 0.8 9000 12.7 54.9 265 5 2 27.9 15.3 13.7 56.7 -16.7 204 1.0 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 * * * * * * 08/17/2024 at 0900 MDT | 08/17/2024 at 1200 MDT | CAPE... +41.0 LI... +2.1 | CAPE... +11.2 LI... +2.4 CINH... -38.9 K Index... -3.8 | CINH... -13.6 K Index... -10.9 | 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 -64.3 -83.7 260 19 10 2.5 1.4 | -64.5 -84.1 265 19 10 2.4 1.3 45000 -59.5 -75.1 260 26 14 4.7 2.6 | -59.4 -74.9 265 30 16 5.1 2.8 40000 -51.4 -60.5 265 36 19 7.1 3.9 | -50.9 -59.6 265 38 20 6.4 3.5 38000 -47.1 -52.8 265 40 20 7.1 3.9 | -47.1 -52.8 265 39 20 6.4 3.5 36000 -42.8 -45.0 265 43 22 7.8 4.3 | -43.2 -45.8 260 40 21 7.4 4.1 34000 -38.0 -36.4 270 37 19 8.0 4.4 | -38.6 -37.5 260 34 17 7.8 4.3 32000 -33.2 -27.8 275 32 16 8.1 4.4 | -33.9 -29.0 255 28 14 8.1 4.4 30000 -28.7 -19.7 280 26 13 7.4 4.1 | -29.3 -20.7 255 24 12 7.7 4.2 29000 -25.9 -14.6 285 23 12 7.4 4.1 | -26.4 -15.5 260 22 11 7.7 4.2 28000 -23.8 -10.8 290 21 11 6.8 3.7 | -24.1 -11.4 260 20 10 7.3 4.0 27000 -21.8 -7.2 300 20 10 6.8 3.7 | -22.0 -7.6 265 17 9 7.3 4.0 26000 -19.7 -3.5 305 20 10 6.8 3.7 | -19.8 -3.6 270 15 8 7.3 4.0 25000 -17.7 0.1 310 19 10 7.2 4.0 | -17.6 0.3 275 13 6 7.8 4.3 24000 -15.5 4.1 310 17 9 7.2 4.0 | -15.2 4.6 270 11 6 7.8 4.3 23000 -13.4 7.9 310 15 8 7.2 4.0 | -12.9 8.8 270 10 5 7.8 4.3 22000 -11.2 11.8 310 13 6 8.1 4.5 | -10.5 13.1 265 9 5 8.0 4.4 21000 -8.7 16.3 290 10 5 8.1 4.4 | -8.1 17.4 245 9 5 8.0 4.4 20000 -6.3 20.7 265 8 4 8.0 4.4 | -5.7 21.7 230 10 5 8.0 4.4 19500 -5.1 22.8 250 8 4 7.3 4.0 | -4.6 23.7 225 11 6 7.6 4.2 19000 -4.2 24.4 240 10 5 6.6 3.6 | -3.5 25.7 225 12 6 7.4 4.1 18500 -3.2 26.2 235 12 6 6.7 3.6 | -2.4 27.7 225 12 6 7.4 4.0 18000 -2.3 27.9 230 13 7 5.9 3.2 | -1.3 29.7 225 12 6 7.4 4.1 17500 -1.5 29.3 230 13 7 6.1 3.4 | -0.2 31.6 225 12 6 7.4 4.1 17000 -0.7 30.7 225 14 7 7.0 3.8 | 0.9 33.6 230 11 6 6.8 3.7 16500 0.5 32.9 225 14 7 7.9 4.3 | 1.8 35.2 240 12 6 6.2 3.4 16000 1.6 34.9 225 14 7 8.0 4.4 | 2.7 36.9 255 12 6 6.3 3.4 15500 2.8 37.0 225 14 7 8.8 4.8 | 3.6 38.5 265 13 7 7.2 3.9 15000 4.0 39.2 230 14 7 8.9 4.9 | 4.6 40.3 270 13 7 7.4 4.1 14500 5.8 42.4 235 14 7 9.2 5.0 | 6.3 43.3 280 13 7 10.1 5.5 14000 7.2 45.0 240 13 7 9.5 5.2 | 7.7 45.9 280 12 6 10.3 5.6 13500 8.6 47.5 245 13 7 9.8 5.3 | 9.2 48.6 280 11 6 9.6 5.3 13000 9.9 49.8 250 13 7 7.9 4.3 | 10.6 51.1 280 11 6 9.3 5.1 12500 11.1 52.0 260 13 7 8.8 4.8 | 12.0 53.6 280 11 6 10.3 5.7 12000 12.4 54.3 265 13 7 7.8 4.3 | 13.5 56.3 280 10 5 9.4 5.2 11750 13.0 55.4 270 13 7 7.0 3.9 | 14.2 57.6 280 10 5 9.0 5.0 11500 13.5 56.3 275 13 7 8.0 4.4 | 14.9 58.8 280 10 5 10.0 5.5 11250 14.2 57.6 275 13 7 8.1 4.5 | 15.7 60.3 280 10 5 10.1 5.6 11000 14.8 58.6 280 13 7 8.2 4.5 | 16.4 61.5 280 10 5 10.0 5.5 10750 15.4 59.7 280 13 7 8.3 4.6 | 17.2 63.0 280 10 5 9.9 5.4 10500 16.0 60.8 280 13 7 6.1 3.3 | 17.9 64.2 280 9 5 10.1 5.5 10250 16.3 61.3 280 12 6 4.6 2.5 | 18.7 65.7 280 9 5 10.6 5.8 10000 16.6 61.9 280 12 6 4.8 2.6 | 19.4 66.9 280 9 5 9.8 5.4 9750 16.9 62.4 275 12 6 5.6 3.1 | 20.2 68.4 280 9 5 12.5 6.9 9500 17.4 63.3 270 10 5 9.0 5.0 | 21.4 70.5 280 8 4 19.5 10.7 9250 18.0 64.4 265 8 4 11.9 6.5 | 22.9 73.2 280 8 4 22.6 12.4 9000 18.7 65.7 255 6 3 8.1 4.5 | 24.5 76.1 280 8 4 19.6 10.8 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 08/17/2024 at 1500 MDT | 08/17/2024 at 1800 MDT | CAPE... +108.2 LI... +0.6 | CAPE... +201.2 LI... -0.3 CINH... -12.8 K Index... +14.5 | CINH... -20.5 K Index... +21.6 | 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 -64.9 -84.8 270 21 11 2.1 1.1 | -65.2 -85.4 265 17 9 1.9 1.0 45000 -59.9 -75.8 270 34 18 5.7 3.1 | -60.0 -76.0 275 32 16 6.1 3.3 40000 -50.7 -59.3 270 40 21 6.6 3.6 | -50.3 -58.5 275 41 21 6.5 3.5 38000 -46.7 -52.1 265 41 21 6.6 3.6 | -46.5 -51.7 275 40 20 6.5 3.5 36000 -42.7 -44.9 260 41 21 7.4 4.1 | -42.5 -44.5 270 39 20 8.0 4.4 34000 -38.1 -36.6 250 37 19 7.6 4.2 | -37.5 -35.5 270 37 19 8.4 4.6 32000 -33.6 -28.5 245 34 17 7.9 4.3 | -32.5 -26.5 265 35 18 8.5 4.7 30000 -29.2 -20.6 240 29 15 7.2 3.9 | -28.3 -18.9 255 34 17 6.8 3.7 29000 -26.5 -15.7 240 27 14 7.2 3.9 | -26.3 -15.3 250 33 17 6.8 3.7 28000 -24.4 -11.9 240 24 12 7.2 3.9 | -23.7 -10.7 240 32 17 6.8 3.7 27000 -22.2 -8.0 240 21 11 7.2 3.9 | -21.7 -7.1 240 29 15 6.8 3.7 26000 -20.1 -4.2 235 18 9 7.2 3.9 | -19.7 -3.5 235 27 14 6.8 3.7 25000 -17.9 -0.2 235 16 8 7.8 4.3 | -17.6 0.3 230 25 13 7.7 4.2 24000 -15.6 3.9 230 16 8 7.8 4.3 | -15.3 4.5 225 24 12 7.7 4.2 23000 -13.2 8.2 225 17 9 7.8 4.3 | -13.0 8.6 225 23 12 7.8 4.3 22000 -10.9 12.4 225 17 9 7.8 4.3 | -10.7 12.7 220 21 11 7.5 4.1 21000 -8.6 16.5 225 17 9 7.9 4.3 | -8.5 16.7 215 16 8 7.7 4.2 20000 -6.3 20.7 225 17 9 8.1 4.4 | -6.4 20.5 205 12 6 7.9 4.3 19500 -5.1 22.8 225 17 9 7.6 4.2 | -5.2 22.6 200 10 5 8.4 4.6 19000 -4.1 24.6 230 15 8 7.2 4.0 | -4.0 24.8 195 9 5 8.6 4.7 18500 -3.1 26.4 240 13 6 7.2 4.0 | -2.7 27.1 190 8 4 8.6 4.7 18000 -2.0 28.4 250 11 6 9.1 5.0 | -1.4 29.5 185 8 4 9.6 5.3 17500 -0.7 30.7 255 9 5 9.0 5.0 | -0.0 32.0 185 7 4 9.5 5.2 17000 0.5 32.9 265 8 4 9.5 5.2 | 1.4 34.5 185 7 3 9.4 5.2 16500 2.0 35.6 265 7 4 9.8 5.4 | 2.8 37.0 185 7 3 9.4 5.1 16000 3.5 38.3 270 7 4 9.9 5.4 | 4.2 39.6 185 6 3 9.4 5.1 15500 4.9 40.8 270 6 3 9.5 5.2 | 5.5 41.9 185 6 3 9.5 5.2 15000 6.3 43.3 270 6 3 9.7 5.3 | 6.9 44.4 190 6 3 9.8 5.4 14500 8.4 47.1 270 5 2 10.2 5.6 | 8.2 46.8 190 6 3 7.5 4.1 14000 9.9 49.8 275 4 2 10.1 5.6 | 9.5 49.1 190 6 3 9.5 5.2 13500 11.5 52.7 275 4 2 10.2 5.6 | 10.9 51.6 195 6 3 9.5 5.2 13000 12.9 55.2 275 4 2 8.7 4.8 | 12.3 54.1 195 7 3 9.3 5.1 12500 14.3 57.7 280 3 2 10.4 5.7 | 14.3 57.7 195 7 4 8.6 4.7 12000 15.8 60.4 280 3 2 9.4 5.2 | 15.6 60.1 190 7 4 9.6 5.3 11750 16.5 61.7 280 3 1 9.1 5.0 | 16.4 61.5 190 7 4 9.9 5.4 11500 17.2 63.0 280 3 1 10.0 5.5 | 17.1 62.8 190 7 4 8.8 4.8 11250 18.0 64.4 285 3 1 10.2 5.6 | 17.7 63.9 190 7 4 8.5 4.6 11000 18.7 65.7 285 3 1 10.2 5.6 | 18.3 64.9 190 7 4 8.7 4.8 10750 19.5 67.1 285 2 1 10.2 5.6 | 19.0 66.2 190 7 4 10.8 5.9 10500 20.2 68.4 290 2 1 10.6 5.8 | 19.9 67.8 185 7 4 10.8 5.9 10250 21.1 70.0 290 2 1 10.8 5.9 | 20.6 69.1 185 7 3 9.5 5.2 10000 21.9 71.4 295 2 1 11.0 6.0 | 21.3 70.3 185 7 3 9.5 5.2 9750 22.7 72.9 295 2 1 10.2 5.6 | 22.0 71.6 185 6 3 10.6 5.8 9500 23.5 74.3 300 2 1 16.0 8.8 | 22.9 73.2 185 6 3 13.4 7.3 9250 25.1 77.2 290 2 1 27.8 15.3 | 23.9 75.0 180 6 3 14.2 7.8 9000 26.7 80.1 285 2 1 6.4 3.5 | 24.9 76.8 180 5 3 14.0 7.7 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 ________________________________________________________________________________ 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