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Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
774 UXUS97 KPUB 181205 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0605 MDT Tuesday, June 18, 2024 This forecast is for Villa Grove, CO for Tuesday, June 18, 2024: If the trigger temperature of 62.4 F/16.9 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1123 ft/min (5.7 m/s) Maximum height of thermals.................. 21149 ft MSL (12171 ft AGL) Forecast maximum temperature................... 78.0 F/26.0 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................. 17611 ft MSL (8633 ft AGL) Thermal soaring outlook for Wednesday 06/19.... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:40:02 / 20:29:47 MDT Total possible sunshine........... 14 hr 49 min 45 sec (889 min 45 sec) Altitude of sun at 13:04:55 MDT... 75.12 degrees Upper air data from numerical model forecast valid on 06/18/2024 at 0600 MDT Freezing level.................. 15135 ft MSL (6157 ft AGL) Convective condensation level... 22053 ft MSL (13075 ft AGL) Lifted condensation level....... 22008 ft MSL (13030 ft AGL) Lifted index.................... -0.1 K index......................... +1.5 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 -58.8 -73.8 230 56 29 3.3 1.8 M M M M M 45000 -54.9 -66.8 230 66 34 -0.1 -0.0 M M M M M 40000 -54.6 -66.3 220 47 24 7.4 4.1 M M M M M 38000 -50.1 -58.2 220 46 24 7.4 4.1 M M M M M 36000 -45.7 -50.3 215 45 23 7.4 4.1 M M M M M 34000 -41.2 -42.2 220 45 23 7.5 4.1 M M M M M 32000 -36.7 -34.1 220 45 23 7.5 4.1 M M M M M 30000 -32.2 -26.0 220 46 24 7.8 4.3 32.5 90.5 5.5 M M 29000 -29.2 -20.6 225 48 24 7.8 4.3 31.6 88.9 4.8 M M 28000 -26.9 -16.4 225 49 25 7.8 4.3 31.0 87.8 4.3 M M 27000 -24.5 -12.1 225 49 25 8.4 4.6 30.4 86.7 3.9 M M 26000 -22.0 -7.6 230 49 25 8.4 4.6 29.9 85.8 3.5 M M 25000 -19.5 -3.1 230 50 26 8.4 4.6 29.5 85.0 3.1 M M 24000 -17.2 1.0 235 50 26 6.8 3.7 28.7 83.7 2.5 M M 23000 -15.2 4.6 235 50 26 6.8 3.7 27.6 81.7 1.5 M M 22000 -13.2 8.2 235 51 26 6.8 3.7 26.6 79.9 0.7 M M 21000 -11.1 12.0 235 50 26 7.4 4.0 25.7 78.3 -0.1 1111 5.6 20000 -8.8 16.2 235 49 25 7.4 4.1 24.9 76.8 -0.8 1014 5.2 19500 -7.7 18.1 235 48 25 7.4 4.1 24.5 76.1 -1.1 966 4.9 19000 -6.6 20.1 235 48 25 7.3 4.0 24.2 75.5 -1.4 917 4.7 18500 -5.6 21.9 230 46 24 6.0 3.3 23.6 74.5 -1.9 873 4.4 18000 -4.7 23.5 230 45 23 6.1 3.4 23.0 73.5 -2.5 830 4.2 17500 -3.8 25.2 225 44 22 5.0 2.7 22.4 72.4 -3.0 789 4.0 17000 -3.2 26.2 225 41 21 4.4 2.4 21.5 70.7 -3.9 756 3.8 16500 -2.6 27.3 220 38 19 4.5 2.5 20.6 69.2 -4.8 724 3.7 16000 -1.8 28.8 220 36 18 6.1 3.3 19.9 67.9 -5.6 686 3.5 15500 -1.0 30.2 225 34 17 5.8 3.2 19.3 66.8 -6.2 646 3.3 15000 0.8 33.4 225 29 15 10.4 5.7 18.9 66.1 -6.7 571 2.9 14500 2.0 35.6 230 25 13 5.0 2.8 18.7 65.7 -6.9 518 2.6 14000 3.0 37.4 235 23 12 8.2 4.5 18.2 64.7 -7.5 476 2.4 13500 4.1 39.4 245 22 11 7.7 4.2 17.8 64.1 -7.8 427 2.2 13000 5.0 41.0 255 22 11 5.8 3.2 17.3 63.1 -8.4 384 2.0 12500 6.0 42.8 260 26 13 6.6 3.6 16.8 62.2 -8.9 340 1.7 12000 6.9 44.4 265 28 15 6.0 3.3 16.3 61.3 -9.5 298 1.5 11750 7.4 45.3 270 28 15 6.5 3.6 16.0 60.8 -9.8 276 1.4 11500 7.8 46.0 270 28 15 6.4 3.5 15.7 60.3 -10.1 255 1.3 11250 8.3 46.9 270 28 15 6.4 3.5 15.5 59.8 -10.4 234 1.2 11000 8.8 47.8 275 28 14 6.6 3.6 15.2 59.4 -10.7 213 1.1 10750 9.2 48.6 270 25 13 4.6 2.5 14.9 58.9 -11.0 193 1.0 10500 9.4 48.9 270 23 12 2.8 1.6 14.4 58.0 -11.6 179 0.9 10250 9.6 49.3 270 21 11 3.4 1.9 13.9 57.1 -12.1 165 0.8 10000 9.8 49.6 275 19 10 2.2 1.2 13.4 56.2 -12.7 152 0.8 9750 10.0 50.0 270 17 9 0.7 0.4 12.8 55.1 -13.3 141 0.7 9500 10.1 50.2 270 15 8 2.6 1.4 12.2 53.9 -14.0 130 0.7 9250 10.1 50.2 265 13 7 -5.3 -2.9 11.5 52.7 -14.7 121 0.6 9000 7.8 46.0 250 6 3 -71.2 -39.1 8.5 47.2 -17.7 182 0.9 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 * * * * * * 06/18/2024 at 0900 MDT | 06/18/2024 at 1200 MDT | CAPE... 0.0 LI... +2.2 | CAPE... 0.0 LI... +3.6 CINH... 0.0 K Index... +11.9 | CINH... 0.0 K Index... -7.7 | 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 -59.4 -74.9 230 58 30 2.1 1.1 | -58.1 -72.6 225 51 26 2.5 1.4 45000 -56.6 -69.9 225 68 35 1.0 0.5 | -54.6 -66.3 230 71 36 1.1 0.6 40000 -54.7 -66.5 220 64 33 7.1 3.9 | -52.8 -63.0 235 72 37 4.3 2.4 38000 -50.4 -58.7 220 62 32 7.1 3.9 | -49.8 -57.6 235 70 36 5.0 2.7 36000 -46.1 -51.0 220 61 31 7.1 3.9 | -46.8 -52.2 230 68 35 5.0 2.7 34000 -41.7 -43.1 220 60 31 7.3 4.0 | -42.9 -45.2 230 66 34 7.3 4.0 32000 -37.4 -35.3 220 61 31 7.3 4.0 | -38.5 -37.3 230 64 33 7.3 4.0 30000 -32.8 -27.0 225 60 31 7.8 4.3 | -33.5 -28.3 230 60 31 7.6 4.2 29000 -30.5 -22.9 225 60 31 7.8 4.3 | -31.3 -24.3 230 58 30 7.6 4.2 28000 -27.6 -17.7 230 60 31 7.8 4.3 | -29.0 -20.2 230 56 29 7.5 4.1 27000 -25.2 -13.4 230 58 30 8.0 4.4 | -26.6 -15.9 230 55 28 8.1 4.5 26000 -22.9 -9.2 230 56 29 8.0 4.4 | -24.2 -11.6 235 54 28 8.1 4.5 25000 -20.5 -4.9 230 54 28 8.0 4.4 | -21.7 -7.1 235 53 28 8.1 4.5 24000 -18.2 -0.8 230 51 26 7.2 4.0 | -19.3 -2.7 235 52 27 8.1 4.4 23000 -16.0 3.2 235 48 25 7.3 4.0 | -16.9 1.6 235 50 26 8.1 4.4 22000 -13.8 7.2 240 45 23 7.3 4.0 | -14.4 6.1 235 48 25 8.1 4.5 21000 -11.8 10.8 240 44 23 6.0 3.3 | -12.1 10.2 240 46 24 7.4 4.1 20000 -10.1 13.8 240 45 23 6.2 3.4 | -9.9 14.2 240 45 23 7.4 4.1 19500 -9.3 15.3 240 45 23 6.5 3.6 | -8.8 16.2 240 44 23 7.4 4.1 19000 -8.4 16.9 240 46 24 7.0 3.8 | -7.7 18.1 240 43 22 6.8 3.7 18500 -7.2 19.0 240 46 23 8.2 4.5 | -6.9 19.6 245 42 22 4.2 2.3 18000 -5.9 21.4 240 45 23 8.4 4.6 | -6.4 20.5 245 41 21 4.5 2.5 17500 -4.7 23.5 235 45 23 6.3 3.5 | -5.7 21.7 245 39 20 5.1 2.8 17000 -3.8 25.2 230 43 22 5.7 3.1 | -5.0 23.0 245 35 18 5.3 2.9 16500 -2.9 26.8 225 41 21 5.5 3.0 | -4.2 24.4 245 31 16 5.4 2.9 16000 -2.2 28.0 225 40 21 4.5 2.5 | -3.5 25.7 240 25 13 5.4 3.0 15500 -1.6 29.1 230 38 20 4.6 2.5 | -2.7 27.1 235 19 10 5.0 2.7 15000 -0.8 30.6 230 36 18 7.4 4.0 | -1.0 30.2 220 14 7 10.1 5.5 14500 0.7 33.3 230 28 14 5.5 3.0 | 0.3 32.5 215 13 6 6.6 3.6 14000 1.7 35.1 230 24 12 9.0 4.9 | 1.5 34.7 215 12 6 10.0 5.5 13500 3.0 37.4 230 21 11 8.6 4.7 | 3.0 37.4 215 12 6 9.3 5.1 13000 4.1 39.4 235 20 10 6.8 3.7 | 4.4 39.9 215 12 6 9.8 5.4 12500 5.2 41.4 245 21 11 7.2 3.9 | 5.8 42.4 215 12 6 9.7 5.3 12000 6.2 43.2 250 21 11 6.0 3.3 | 7.3 45.1 215 11 6 10.0 5.5 11750 6.6 43.9 255 20 10 5.7 3.1 | 8.0 46.4 215 11 6 10.2 5.6 11500 7.0 44.6 255 19 10 5.7 3.1 | 8.8 47.8 215 11 6 10.1 5.6 11250 7.4 45.3 255 18 9 5.8 3.2 | 9.6 49.3 215 11 6 10.3 5.6 11000 7.8 46.0 260 17 9 5.9 3.2 | 10.3 50.5 215 11 6 10.7 5.9 10750 8.3 46.9 260 15 8 7.0 3.9 | 11.1 52.0 215 11 6 10.3 5.7 10500 8.8 47.8 260 13 7 7.8 4.3 | 11.9 53.4 210 11 6 9.7 5.3 10250 9.3 48.7 260 10 5 7.9 4.4 | 12.6 54.7 210 11 5 10.3 5.6 10000 10.0 50.0 255 9 4 9.2 5.0 | 13.4 56.1 210 10 5 11.2 6.2 9750 10.7 51.3 255 8 4 10.3 5.7 | 14.3 57.7 210 10 5 12.3 6.7 9500 11.5 52.7 255 7 4 10.4 5.7 | 15.2 59.4 210 10 5 10.5 5.8 9250 12.3 54.1 255 6 3 15.9 8.7 | 16.1 61.0 210 9 5 17.7 9.7 9000 14.5 58.1 255 6 3 49.8 27.3 | 19.2 66.6 210 9 4 81.0 44.4 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 06/18/2024 at 1500 MDT | 06/18/2024 at 1800 MDT | CAPE... +30.3 LI... +0.5 | CAPE... +31.4 LI... +0.2 CINH... -20.7 K Index... +19.1 | CINH... -10.3 K Index... +21.0 | 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 -58.2 -72.8 230 59 30 1.7 0.9 | -58.2 -72.8 235 55 28 1.8 1.0 45000 -55.9 -68.6 230 72 37 1.0 0.5 | -55.8 -68.4 235 74 38 0.5 0.3 40000 -54.1 -65.4 240 69 36 5.5 3.0 | -54.9 -66.8 240 72 37 5.7 3.1 38000 -50.5 -58.9 235 68 35 5.9 3.3 | -51.0 -59.8 240 71 36 6.4 3.5 36000 -47.0 -52.6 235 67 34 5.9 3.3 | -47.2 -53.0 240 69 36 6.4 3.5 34000 -42.9 -45.2 240 65 33 7.3 4.0 | -43.0 -45.4 240 65 34 7.2 4.0 32000 -38.6 -37.5 240 62 32 7.3 4.0 | -38.7 -37.7 240 60 31 7.2 4.0 30000 -33.7 -28.7 240 60 31 7.3 4.0 | -33.8 -28.8 240 56 29 7.3 4.0 29000 -31.5 -24.7 240 59 30 7.3 4.0 | -31.6 -24.9 240 54 28 7.3 4.0 28000 -29.3 -20.7 240 58 30 7.3 4.0 | -29.5 -21.1 240 53 27 7.3 4.0 27000 -26.9 -16.4 240 55 28 8.1 4.5 | -27.1 -16.8 240 52 27 7.9 4.3 26000 -24.5 -12.1 240 52 27 8.1 4.5 | -24.8 -12.6 240 51 26 7.9 4.3 25000 -22.0 -7.6 240 49 25 8.1 4.5 | -22.5 -8.5 240 50 26 7.9 4.3 24000 -19.6 -3.3 240 48 24 8.3 4.6 | -20.1 -4.2 240 47 24 7.8 4.3 23000 -17.1 1.2 240 47 24 8.3 4.6 | -17.8 -0.0 240 43 22 7.8 4.3 22000 -14.6 5.7 235 47 24 8.5 4.7 | -15.4 4.3 235 39 20 7.9 4.3 21000 -12.7 9.1 240 42 22 5.6 3.1 | -13.3 8.1 235 34 17 7.3 4.0 20000 -11.1 12.0 240 35 18 5.8 3.2 | -11.2 11.8 235 28 14 7.5 4.1 19500 -10.3 13.5 240 32 16 6.0 3.3 | -10.1 13.8 230 25 13 7.7 4.2 19000 -9.5 14.9 240 28 15 6.6 3.6 | -9.1 15.6 230 22 11 8.0 4.4 18500 -8.4 16.9 240 25 13 7.5 4.1 | -7.9 17.8 225 22 11 8.2 4.5 18000 -7.3 18.9 235 22 11 7.4 4.1 | -6.7 19.9 220 22 11 8.2 4.5 17500 -6.2 20.8 230 19 10 8.6 4.7 | -5.4 22.3 220 22 11 8.4 4.6 17000 -4.9 23.2 225 18 9 8.7 4.8 | -4.1 24.6 215 22 11 8.4 4.6 16500 -3.6 25.5 215 17 9 8.7 4.7 | -2.8 27.0 210 22 12 8.6 4.7 16000 -2.4 27.7 210 17 9 8.6 4.7 | -0.8 30.6 205 22 12 8.8 4.8 15500 -0.4 31.3 205 17 9 10.0 5.5 | 0.5 32.9 205 23 12 9.9 5.4 15000 1.2 34.2 200 17 9 11.5 6.3 | 2.0 35.6 200 22 11 10.8 5.9 14500 2.6 36.7 200 17 9 6.8 3.8 | 3.3 37.9 200 22 11 6.9 3.8 14000 3.9 39.0 200 17 9 9.9 5.5 | 4.7 40.5 200 22 11 10.0 5.5 13500 5.4 41.7 195 17 8 9.1 5.0 | 6.1 43.0 200 21 11 9.4 5.2 13000 6.8 44.2 195 16 8 10.2 5.6 | 7.6 45.7 200 21 11 10.1 5.5 12500 8.3 46.9 195 16 8 10.1 5.6 | 9.0 48.2 195 20 10 10.2 5.6 12000 9.7 49.5 195 16 8 9.5 5.2 | 10.4 50.7 190 18 9 9.2 5.0 11750 10.5 50.9 190 15 8 10.2 5.6 | 11.2 52.2 190 18 9 10.5 5.7 11500 11.2 52.2 190 15 8 10.0 5.5 | 11.9 53.4 190 17 9 10.2 5.6 11250 12.0 53.6 190 15 8 10.2 5.6 | 12.7 54.9 190 17 9 10.1 5.5 11000 12.8 55.0 190 15 8 10.5 5.8 | 13.4 56.1 185 16 8 9.9 5.4 10750 13.5 56.3 190 15 8 10.4 5.7 | 14.2 57.6 185 15 8 10.1 5.5 10500 14.3 57.7 190 15 8 10.1 5.5 | 14.9 58.8 185 15 8 10.1 5.6 10250 15.1 59.2 190 15 7 10.5 5.8 | 15.7 60.3 180 14 7 10.3 5.7 10000 15.9 60.6 190 14 7 11.2 6.1 | 16.5 61.7 180 14 7 10.6 5.8 9750 16.7 62.1 185 14 7 12.1 6.6 | 17.3 63.1 180 13 7 10.8 6.0 9500 17.6 63.7 185 13 7 10.8 5.9 | 18.1 64.6 175 13 7 10.3 5.6 9250 18.5 65.3 185 13 7 18.0 9.9 | 18.9 66.0 175 12 6 13.1 7.2 9000 21.5 70.7 180 11 6 78.8 43.2 | 20.5 68.9 165 9 5 38.1 20.9 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