Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
674 UXUS97 KPUB 261206 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0606 MDT Sunday, May 26, 2024 This forecast is for Villa Grove, CO for Sunday, May 26, 2024: If the trigger temperature of 48.2 F/9.0 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1124 ft/min (5.7 m/s) Maximum height of thermals.................. 21299 ft MSL (12327 ft AGL) Forecast maximum temperature................... 65.0 F/18.8 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................. 17439 ft MSL (8468 ft AGL) Thermal soaring outlook for Monday 05/27....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:44:14 / 20:17:13 MDT Total possible sunshine........... 14 hr 32 min 58 sec (872 min 58 sec) Altitude of sun at 13:00:44 MDT... 73.04 degrees Upper air data from numerical model forecast valid on 05/26/2024 at 0600 MDT Freezing level.................. 10144 ft MSL (1172 ft AGL) Convective condensation level... 18711 ft MSL (9739 ft AGL) Lifted condensation level....... 19796 ft MSL (10825 ft AGL) Lifted index.................... -2.7 K index......................... -16.9 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 -54.3 -65.7 250 50 26 2.3 1.2 M M M M M 45000 -51.2 -60.2 255 64 33 -0.4 -0.2 M M M M M 40000 -51.9 -61.4 270 69 36 -0.4 -0.2 M M M M M 38000 -51.4 -60.5 275 68 35 1.4 0.8 M M M M M 36000 -50.5 -58.9 275 64 33 1.4 0.8 M M M M M 34000 -48.8 -55.8 275 61 31 6.3 3.5 M M M M M 32000 -44.9 -48.8 280 59 30 6.4 3.5 M M M M M 30000 -40.4 -40.7 280 55 28 7.1 3.9 23.5 74.3 4.0 M M 29000 -38.3 -36.9 280 51 26 7.1 3.9 22.4 72.3 3.2 M M 28000 -36.2 -33.2 280 48 25 7.1 3.9 21.5 70.7 2.5 M M 27000 -33.9 -29.0 280 46 23 9.1 5.0 20.7 69.3 2.0 M M 26000 -31.3 -24.3 280 45 23 8.9 4.9 20.3 68.6 1.6 M M 25000 -28.6 -19.5 285 45 23 8.9 4.9 20.0 68.1 1.4 M M 24000 -26.0 -14.8 285 45 23 8.4 4.6 19.8 67.6 1.2 M M 23000 -23.5 -10.3 285 44 23 8.2 4.5 19.2 66.5 0.7 M M 22000 -21.0 -5.8 290 43 22 8.2 4.5 18.7 65.6 0.3 M M 21000 -18.6 -1.5 290 42 21 7.2 4.0 18.1 64.6 -0.2 1098 5.6 20000 -16.4 2.5 290 36 19 7.3 4.0 17.2 63.0 -1.0 1003 5.1 19500 -15.3 4.5 290 34 17 7.3 4.0 16.8 62.3 -1.4 955 4.9 19000 -14.2 6.4 290 31 16 7.3 4.0 16.4 61.6 -1.7 908 4.6 18500 -13.1 8.4 290 29 15 7.3 4.0 16.1 60.9 -2.1 860 4.4 18000 -12.1 10.2 290 29 15 7.2 4.0 15.6 60.2 -2.5 813 4.1 17500 -11.0 12.2 295 30 15 7.1 3.9 15.2 59.4 -2.9 766 3.9 17000 -10.0 14.0 295 31 16 5.8 3.2 14.7 58.4 -3.4 723 3.7 16500 -9.1 15.6 295 32 16 5.9 3.3 14.0 57.3 -4.0 681 3.5 16000 -8.3 17.1 295 33 17 5.5 3.0 13.4 56.1 -4.6 641 3.3 15500 -7.5 18.5 300 34 17 5.5 3.0 12.7 54.8 -5.3 601 3.1 15000 -6.2 20.8 300 34 17 6.0 3.3 11.7 53.1 -6.3 541 2.8 14500 -5.3 22.5 300 31 16 4.6 2.5 11.1 52.0 -6.9 500 2.5 14000 -4.7 23.5 300 28 15 6.0 3.3 10.2 50.4 -7.8 468 2.4 13500 -3.8 25.2 300 29 15 6.7 3.7 9.7 49.5 -8.4 425 2.2 13000 -3.0 26.6 300 31 16 5.1 2.8 9.1 48.4 -9.0 385 2.0 12500 -2.2 28.0 305 35 18 5.6 3.1 8.4 47.2 -9.8 346 1.8 12000 -1.3 29.7 305 40 21 5.6 3.0 7.8 46.1 -10.5 307 1.6 11750 -1.0 30.2 305 41 21 3.6 2.0 7.4 45.4 -10.9 290 1.5 11500 -0.9 30.4 305 41 21 2.8 1.5 6.9 44.4 -11.5 278 1.4 11250 -0.7 30.7 305 42 21 3.4 1.9 6.4 43.5 -12.1 266 1.4 11000 -0.6 30.9 300 41 21 0.8 0.4 5.9 42.5 -12.8 255 1.3 10750 -0.7 30.7 300 38 19 1.5 0.8 5.1 41.2 -13.6 249 1.3 10500 -0.4 31.3 295 34 18 5.0 2.8 4.7 40.4 -14.1 235 1.2 10250 -0.1 31.8 295 31 16 4.9 2.7 4.3 39.7 -14.6 218 1.1 10000 0.3 32.5 290 28 15 6.3 3.5 4.0 39.2 -15.0 199 1.0 9750 0.8 33.4 285 26 13 6.9 3.8 3.8 38.8 -15.2 176 0.9 9500 1.2 34.2 285 23 12 5.1 2.8 3.5 38.3 -15.6 156 0.8 9250 1.5 34.7 280 19 10 1.2 0.7 3.0 37.4 -16.1 141 0.7 9000 1.2 34.2 270 10 5 -8.6 -4.7 2.0 35.7 -17.1 141 0.7 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 * * * * * * 05/26/2024 at 0900 MDT | 05/26/2024 at 1200 MDT | CAPE... 0.0 LI... +1.6 | CAPE... +2.3 LI... +1.7 CINH... 0.0 K Index... -12.4 | CINH... -16.8 K Index... +0.5 | 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 -54.6 -66.3 255 49 25 1.4 0.8 | -54.9 -66.8 255 47 24 1.2 0.7 45000 -52.8 -63.0 260 66 34 -0.7 -0.4 | -53.5 -64.3 265 67 35 -0.9 -0.5 40000 -53.8 -64.8 265 77 39 -0.6 -0.3 | -54.8 -66.6 275 71 36 -0.8 -0.4 38000 -52.3 -62.1 270 74 38 3.7 2.0 | -53.3 -63.9 280 66 34 3.7 2.0 36000 -50.1 -58.2 270 70 36 3.7 2.0 | -51.1 -60.0 285 60 31 3.7 2.0 34000 -47.7 -53.9 270 64 33 4.9 2.7 | -48.2 -54.8 290 55 28 7.0 3.9 32000 -44.4 -47.9 270 55 28 4.9 2.7 | -43.4 -46.1 295 51 26 7.0 3.9 30000 -40.7 -41.3 275 49 25 7.7 4.2 | -39.4 -38.9 295 48 24 6.4 3.5 29000 -38.5 -37.3 275 47 24 7.6 4.2 | -37.5 -35.5 295 46 24 6.4 3.5 28000 -36.2 -33.2 275 45 23 7.7 4.2 | -35.6 -32.1 290 45 23 6.4 3.5 27000 -33.8 -28.8 280 43 22 8.3 4.6 | -33.5 -28.3 290 44 23 8.0 4.4 26000 -31.3 -24.3 280 42 21 8.3 4.5 | -31.1 -24.0 290 44 23 7.9 4.3 25000 -28.8 -19.8 280 40 21 8.3 4.5 | -28.8 -19.8 290 43 22 7.9 4.3 24000 -26.3 -15.3 280 39 20 8.5 4.7 | -26.4 -15.5 290 43 22 8.5 4.7 23000 -23.8 -10.8 285 38 20 8.5 4.7 | -23.8 -10.8 290 41 21 8.5 4.7 22000 -21.2 -6.2 285 38 20 8.5 4.7 | -21.3 -6.3 290 39 20 8.5 4.7 21000 -18.7 -1.7 290 37 19 8.1 4.5 | -18.8 -1.8 290 38 20 7.7 4.2 20000 -16.2 2.8 290 37 19 8.2 4.5 | -16.5 2.3 295 37 19 7.8 4.3 19500 -15.0 5.0 290 37 19 8.2 4.5 | -15.3 4.5 295 36 19 7.8 4.3 19000 -13.8 7.2 295 36 19 8.2 4.5 | -14.2 6.4 295 35 18 7.7 4.2 18500 -12.6 9.3 295 36 19 8.0 4.4 | -12.9 8.8 295 34 17 8.8 4.8 18000 -11.4 11.5 295 36 19 8.0 4.4 | -11.6 11.1 295 31 16 8.7 4.8 17500 -10.2 13.6 295 36 19 7.8 4.3 | -10.3 13.5 295 29 15 7.7 4.2 17000 -9.1 15.6 295 36 19 7.3 4.0 | -9.3 15.3 295 28 15 6.5 3.5 16500 -8.0 17.6 300 36 19 7.4 4.1 | -7.9 17.8 295 28 14 6.1 3.3 16000 -6.9 19.6 300 36 18 6.6 3.6 | -7.0 19.4 300 31 16 5.9 3.2 15500 -5.9 21.4 300 36 19 6.7 3.7 | -6.2 20.8 300 34 17 5.4 3.0 15000 -4.7 23.5 300 37 19 3.8 2.1 | -5.6 21.9 300 33 17 3.3 1.8 14500 -4.1 24.6 300 39 20 3.4 1.9 | -5.2 22.6 300 32 17 2.3 1.3 14000 -3.8 25.2 295 39 20 1.5 0.8 | -4.6 23.7 300 29 15 6.6 3.6 13500 -3.6 25.5 295 37 19 1.6 0.9 | -3.8 25.2 295 24 12 5.7 3.1 13000 -3.4 25.9 295 35 18 3.5 1.9 | -2.7 27.1 290 21 11 10.5 5.8 12500 -2.8 27.0 295 30 16 4.1 2.3 | -1.3 29.7 290 20 11 9.5 5.2 12000 -2.3 27.9 300 26 13 4.3 2.3 | 0.1 32.2 290 20 10 9.8 5.4 11750 -2.0 28.4 295 23 12 5.9 3.2 | 0.9 33.6 290 20 10 10.4 5.7 11500 -1.6 29.1 295 21 11 6.3 3.4 | 1.7 35.1 290 19 10 10.5 5.8 11250 -1.2 29.8 290 20 10 6.7 3.7 | 2.4 36.3 290 19 10 10.3 5.6 11000 -0.7 30.7 290 18 9 8.7 4.8 | 3.2 37.8 290 19 10 9.6 5.3 10750 0.0 32.0 290 17 9 9.9 5.4 | 3.9 39.0 290 19 10 10.0 5.5 10500 0.7 33.3 290 17 9 9.8 5.4 | 4.7 40.5 290 18 9 10.3 5.7 10250 1.5 34.7 290 16 8 10.2 5.6 | 5.5 41.9 290 18 9 10.8 5.9 10000 2.3 36.1 290 15 8 11.1 6.1 | 6.3 43.3 290 18 9 11.6 6.3 9750 3.1 37.6 290 15 8 11.7 6.4 | 7.2 45.0 290 17 9 12.3 6.8 9500 4.0 39.2 290 14 7 10.8 5.9 | 8.1 46.6 290 16 8 11.0 6.0 9250 4.9 40.8 285 13 7 15.8 8.7 | 9.0 48.2 290 15 8 19.2 10.6 9000 7.2 45.0 285 11 6 56.0 30.7 | 12.4 54.3 290 14 7 87.5 48.0 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 05/26/2024 at 1500 MDT | 05/26/2024 at 1800 MDT | CAPE... +53.5 LI... +0.1 | CAPE... +6.9 LI... +0.6 CINH... -4.1 K Index... +5.4 | CINH... -3.0 K Index... -3.1 | 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 -55.5 -67.9 260 54 28 1.0 0.6 | -56.5 -69.7 265 55 28 0.7 0.4 45000 -54.4 -65.9 270 66 34 -1.4 -0.8 | -55.7 -68.3 270 60 31 -0.8 -0.5 40000 -56.6 -69.9 275 62 32 -1.4 -0.8 | -57.0 -70.6 275 57 29 -1.0 -0.5 38000 -54.7 -66.5 285 55 29 4.5 2.5 | -54.6 -66.3 280 51 26 4.7 2.6 36000 -52.0 -61.6 295 49 25 4.5 2.5 | -51.8 -61.2 280 45 23 4.7 2.6 34000 -47.8 -54.0 300 45 23 7.9 4.3 | -47.8 -54.0 285 42 22 8.4 4.6 32000 -43.1 -45.6 300 42 22 7.9 4.3 | -42.8 -45.0 290 42 22 8.4 4.6 30000 -38.1 -36.6 305 42 22 8.6 4.7 | -37.9 -36.2 290 43 22 8.1 4.5 29000 -35.5 -31.9 305 43 22 8.6 4.7 | -35.5 -31.9 290 43 22 8.1 4.5 28000 -32.9 -27.2 310 44 23 8.5 4.7 | -32.4 -26.3 290 43 22 8.2 4.5 27000 -30.6 -23.1 310 45 23 6.8 3.7 | -30.0 -22.0 295 41 21 7.9 4.3 26000 -28.6 -19.5 310 44 23 6.7 3.7 | -27.6 -17.7 295 38 19 7.9 4.3 25000 -26.6 -15.9 305 43 22 6.7 3.7 | -25.3 -13.5 300 35 18 7.9 4.3 24000 -24.6 -12.3 305 42 22 6.2 3.4 | -23.2 -9.8 300 33 17 5.8 3.2 23000 -22.7 -8.9 300 40 21 6.3 3.4 | -21.5 -6.7 300 32 17 5.8 3.2 22000 -20.8 -5.4 295 39 20 6.3 3.5 | -19.8 -3.6 295 32 16 5.8 3.2 21000 -18.8 -1.8 295 35 18 7.7 4.2 | -17.8 -0.0 295 30 15 7.3 4.0 20000 -16.5 2.3 290 30 15 7.7 4.2 | -15.6 3.9 290 27 14 7.4 4.0 19500 -15.4 4.3 290 27 14 7.7 4.2 | -14.5 5.9 285 25 13 7.4 4.0 19000 -14.2 6.4 285 24 12 7.6 4.2 | -13.4 7.9 285 23 12 7.2 4.0 18500 -13.0 8.6 285 21 11 8.7 4.8 | -12.3 9.9 280 21 11 6.7 3.7 18000 -11.7 10.9 275 17 9 8.6 4.7 | -11.4 11.5 280 18 9 6.6 3.6 17500 -10.4 13.3 270 14 7 7.9 4.4 | -10.3 13.5 280 17 8 8.7 4.8 17000 -9.3 15.3 285 16 8 7.6 4.1 | -8.9 16.0 280 17 9 9.0 4.9 16500 -7.7 18.1 300 19 10 6.3 3.5 | -7.6 18.3 285 18 9 8.6 4.7 16000 -6.8 19.8 305 19 10 6.1 3.3 | -6.4 20.5 285 18 9 7.9 4.3 15500 -6.0 21.2 310 20 10 6.8 3.7 | -5.2 22.6 285 18 9 7.9 4.3 15000 -4.9 23.2 305 18 10 8.1 4.5 | -4.1 24.6 285 18 9 8.2 4.5 14500 -3.8 25.2 300 17 9 6.7 3.7 | -2.5 27.5 290 16 8 6.3 3.4 14000 -2.7 27.1 295 17 9 9.6 5.3 | -1.4 29.5 290 16 8 9.2 5.1 13500 -1.3 29.7 295 17 9 9.1 5.0 | -0.1 31.8 290 16 8 8.5 4.7 13000 0.0 32.0 295 17 9 9.8 5.4 | 1.2 34.2 290 16 8 9.9 5.4 12500 1.5 34.7 295 17 9 10.1 5.6 | 2.6 36.7 290 16 8 9.8 5.4 12000 3.0 37.4 295 16 8 9.7 5.3 | 4.0 39.2 290 16 8 9.6 5.3 11750 3.8 38.8 295 16 8 10.7 5.9 | 4.8 40.6 290 16 8 10.4 5.7 11500 4.5 40.1 295 16 8 10.6 5.8 | 5.5 41.9 290 16 8 10.3 5.6 11250 5.3 41.5 295 16 8 10.5 5.7 | 6.3 43.3 290 16 8 10.2 5.6 11000 6.1 43.0 295 16 8 10.2 5.6 | 7.1 44.8 290 16 8 10.0 5.5 10750 6.9 44.4 295 16 8 10.2 5.6 | 7.8 46.0 290 16 8 10.2 5.6 10500 7.6 45.7 295 16 8 10.0 5.5 | 8.6 47.5 290 15 8 10.4 5.7 10250 8.4 47.1 295 15 8 10.6 5.8 | 9.4 48.9 295 15 8 10.5 5.7 10000 9.2 48.6 295 15 8 11.1 6.1 | 10.1 50.2 295 15 8 10.6 5.8 9750 10.0 50.0 295 15 8 11.7 6.4 | 10.9 51.6 295 15 8 10.7 5.9 9500 10.9 51.6 295 14 7 10.7 5.8 | 11.7 53.1 295 14 7 9.9 5.4 9250 11.9 53.4 295 13 7 18.6 10.2 | 12.5 54.5 295 13 7 14.2 7.8 9000 15.1 59.2 295 12 6 83.4 45.8 | 14.5 58.1 290 12 6 47.6 26.1 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