Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
221 UXUS97 KPUB 131217 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0617 MDT Monday, May 13, 2024 This forecast is for Villa Grove, CO for Monday, May 13, 2024: If the trigger temperature of 49.3 F/9.6 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1186 ft/min (6.0 m/s) Maximum height of thermals.................. 21150 ft MSL (12171 ft AGL) Forecast maximum temperature................... 61.0 F/16.6 C Time of trigger temperature.................... 0930 MDT Time of overdevelopment........................ 1500 MDT Middle/high clouds during soaring window....... None Surface winds during soaring window............ 20 mph or less Height of the -3 thermal index................. 18429 ft MSL (9450 ft AGL) Thermal soaring outlook for Tuesday 05/14...... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:53:31 / 20:06:20 MDT Total possible sunshine........... 14 hr 12 min 49 sec (852 min 49 sec) Altitude of sun at 12:59:56 MDT... 70.38 degrees Upper air data from numerical model forecast valid on 05/13/2024 at 0600 MDT Freezing level.................. 12145 ft MSL (3166 ft AGL) Convective condensation level... 14735 ft MSL (5756 ft AGL) Lifted condensation level....... 17219 ft MSL (8240 ft AGL) Lifted index.................... -4.4 K index......................... +18.0 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 -55.6 -68.1 295 14 7 3.5 1.9 M M M M M 45000 -50.8 -59.4 300 17 9 -1.9 -1.0 M M M M M 40000 -53.3 -63.9 350 20 10 -1.6 -0.9 M M M M M 38000 -53.1 -63.6 360 27 14 1.2 0.6 M M M M M 36000 -52.4 -62.3 005 35 18 1.2 0.6 M M M M M 34000 -50.8 -59.4 005 40 21 6.5 3.5 M M M M M 32000 -46.8 -52.2 360 37 19 6.6 3.6 M M M M M 30000 -42.7 -44.9 360 34 17 7.7 4.2 21.6 71.0 4.3 M M 29000 -39.8 -39.6 355 32 16 7.7 4.2 20.6 69.1 3.6 M M 28000 -37.5 -35.5 355 30 16 7.7 4.2 19.9 67.9 3.1 M M 27000 -35.2 -31.4 350 29 15 8.1 4.4 19.3 66.7 2.6 M M 26000 -32.8 -27.0 355 28 14 8.1 4.4 18.6 65.4 2.0 M M 25000 -30.4 -22.7 355 27 14 8.1 4.4 18.0 64.4 1.5 M M 24000 -27.9 -18.2 355 26 13 8.6 4.7 17.5 63.5 1.1 M M 23000 -25.4 -13.7 360 24 13 8.6 4.7 17.0 62.6 0.7 M M 22000 -22.8 -9.0 360 23 12 8.6 4.7 16.6 62.0 0.4 M M 21000 -20.4 -4.7 005 22 11 6.2 3.4 16.0 60.9 -0.2 1175 6.0 20000 -18.6 -1.5 005 22 11 6.4 3.5 14.8 58.7 -1.3 1089 5.5 19500 -17.6 0.3 005 21 11 6.4 3.5 14.3 57.7 -1.8 1046 5.3 19000 -16.7 1.9 005 21 11 6.5 3.6 13.8 56.8 -2.3 1003 5.1 18500 -15.8 3.6 005 22 11 5.9 3.3 13.2 55.8 -2.8 961 4.9 18000 -14.9 5.2 005 23 12 6.0 3.3 12.6 54.6 -3.5 921 4.7 17500 -14.1 6.6 005 25 13 6.6 3.6 12.0 53.5 -4.1 880 4.5 17000 -13.0 8.6 005 26 14 7.4 4.1 11.5 52.8 -4.5 833 4.2 16500 -11.9 10.6 005 28 14 7.4 4.1 11.2 52.1 -4.9 786 4.0 16000 -10.8 12.6 005 28 15 8.0 4.4 10.8 51.5 -5.2 737 3.7 15500 -9.6 14.7 360 28 14 7.8 4.3 10.5 51.0 -5.6 688 3.5 15000 -8.4 16.9 355 28 14 10.0 5.5 10.4 50.7 -5.8 636 3.2 14500 -6.1 21.0 350 27 14 8.4 4.6 10.5 50.9 -5.8 546 2.8 14000 -4.9 23.2 350 26 14 10.1 5.5 10.3 50.5 -6.0 494 2.5 13500 -3.5 25.7 345 26 13 9.9 5.5 10.3 50.5 -6.1 436 2.2 13000 -2.1 28.2 345 24 12 8.5 4.7 10.1 50.2 -6.3 382 1.9 12500 -0.8 30.6 345 23 12 9.6 5.3 10.1 50.1 -6.4 326 1.7 12000 0.5 32.9 340 20 10 7.5 4.1 9.9 49.8 -6.6 274 1.4 11750 1.1 34.0 340 19 10 8.6 4.7 9.7 49.5 -6.8 249 1.3 11500 1.7 35.1 335 18 9 8.9 4.9 9.7 49.4 -6.9 222 1.1 11250 2.3 36.1 335 16 8 8.5 4.7 9.6 49.3 -7.0 196 1.0 11000 2.9 37.2 335 15 8 8.2 4.5 9.5 49.1 -7.2 171 0.9 10750 3.5 38.3 330 14 7 7.3 4.0 9.3 48.8 -7.3 146 0.7 10500 4.0 39.2 330 13 7 7.0 3.8 9.1 48.4 -7.6 124 0.6 10250 4.5 40.1 325 12 6 5.6 3.0 8.9 48.0 -7.9 103 0.5 10000 4.8 40.6 325 11 6 3.3 1.8 8.5 47.2 -8.4 87 0.4 9750 4.9 40.8 320 11 6 1.9 1.0 7.9 46.3 -8.9 74 0.4 9500 5.1 41.2 315 10 5 3.1 1.7 7.4 45.2 -9.6 63 0.3 9250 5.0 41.0 310 10 5 -11.7 -6.4 6.5 43.8 -10.4 59 0.3 9000 1.0 33.8 280 5 2 -99.0 -54.3 1.8 35.2 -15.1 169 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 * * * * * * 05/13/2024 at 0900 MDT | 05/13/2024 at 1200 MDT | CAPE... +632.4 LI... -2.1 | CAPE... +276.0 LI... -1.7 CINH... -7.2 K Index... +13.3 | CINH... 0.0 K Index... +17.0 | 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 -55.3 -67.5 290 12 6 3.2 1.8 | -55.1 -67.2 270 12 6 3.6 2.0 45000 -51.2 -60.2 305 15 8 -2.0 -1.1 | -50.8 -59.4 295 14 7 -3.7 -2.0 40000 -54.4 -65.9 350 12 6 -2.1 -1.1 | -56.4 -69.5 325 12 6 -3.6 -2.0 38000 -53.8 -64.8 005 20 10 2.2 1.2 | -55.3 -67.5 345 17 9 4.1 2.3 36000 -52.5 -62.5 010 30 16 2.2 1.2 | -52.8 -63.0 355 25 13 4.1 2.3 34000 -50.3 -58.5 010 37 19 6.9 3.8 | -49.7 -57.5 360 30 15 6.9 3.8 32000 -46.1 -51.0 005 35 18 7.0 3.8 | -45.6 -50.1 360 30 15 6.9 3.8 30000 -41.9 -43.4 005 34 17 7.3 4.0 | -40.7 -41.3 360 30 15 7.5 4.1 29000 -39.1 -38.4 360 33 17 7.3 4.0 | -38.5 -37.3 005 30 15 7.5 4.1 28000 -36.9 -34.4 360 32 17 7.3 4.0 | -36.2 -33.2 005 30 15 7.5 4.1 27000 -34.7 -30.5 360 32 16 7.8 4.3 | -34.0 -29.2 005 30 15 7.6 4.2 26000 -32.4 -26.3 360 30 16 7.8 4.3 | -31.7 -25.1 360 30 15 7.6 4.2 25000 -30.1 -22.2 355 29 15 7.8 4.3 | -29.4 -20.9 360 29 15 7.6 4.2 24000 -27.7 -17.9 355 28 14 8.4 4.6 | -27.1 -16.8 360 29 15 7.9 4.4 23000 -25.2 -13.4 355 27 14 8.3 4.6 | -24.8 -12.6 355 27 14 7.9 4.3 22000 -22.7 -8.9 355 25 13 8.3 4.6 | -22.4 -8.3 350 26 13 7.9 4.3 21000 -20.4 -4.7 355 24 12 6.6 3.6 | -20.2 -4.4 345 25 13 6.8 3.7 20000 -18.4 -1.1 360 22 12 6.8 3.7 | -18.2 -0.8 340 24 12 6.8 3.7 19500 -17.4 0.7 360 22 11 6.8 3.7 | -17.2 1.0 335 24 12 6.8 3.7 19000 -16.4 2.5 005 21 11 6.9 3.8 | -16.2 2.8 335 23 12 6.8 3.7 18500 -15.5 4.1 005 21 11 5.7 3.1 | -15.1 4.8 335 22 11 7.4 4.1 18000 -14.7 5.5 010 22 11 5.9 3.2 | -14.1 6.6 335 21 11 7.4 4.1 17500 -13.9 7.0 010 23 12 6.9 3.8 | -13.0 8.6 335 20 11 8.0 4.4 17000 -12.7 9.1 010 23 12 7.7 4.2 | -11.8 10.8 335 19 10 8.3 4.6 16500 -11.6 11.1 010 23 12 7.8 4.3 | -10.5 13.1 335 18 9 8.5 4.6 16000 -10.4 13.3 010 23 12 8.0 4.4 | -9.3 15.3 335 17 9 8.9 4.9 15500 -9.2 15.4 005 23 12 7.9 4.3 | -8.0 17.6 335 16 8 8.8 4.8 15000 -7.9 17.8 360 23 12 10.2 5.6 | -5.9 21.4 335 15 7 9.7 5.3 14500 -5.7 21.7 360 23 12 8.4 4.6 | -4.5 23.9 335 14 7 8.3 4.5 14000 -4.4 24.1 355 22 12 9.9 5.4 | -3.2 26.2 335 13 7 10.0 5.5 13500 -3.0 26.6 355 22 11 9.6 5.2 | -1.8 28.8 335 12 6 9.1 5.0 13000 -1.7 28.9 350 22 11 9.1 5.0 | -0.4 31.3 335 11 6 10.0 5.5 12500 -0.2 31.6 350 21 11 9.6 5.3 | 1.1 34.0 340 10 5 10.9 6.0 12000 1.1 34.0 345 21 11 9.1 5.0 | 2.5 36.5 340 10 5 8.5 4.6 11750 1.8 35.2 345 21 11 9.7 5.3 | 3.2 37.8 340 10 5 10.5 5.8 11500 2.5 36.5 345 20 10 9.9 5.5 | 4.0 39.2 340 10 5 10.4 5.7 11250 3.3 37.9 345 20 10 9.1 5.0 | 4.8 40.6 340 9 5 10.1 5.6 11000 3.9 39.0 340 19 10 7.8 4.3 | 5.5 41.9 340 9 5 9.6 5.3 10750 4.5 40.1 340 18 9 8.5 4.6 | 6.2 43.2 340 9 5 10.0 5.5 10500 5.1 41.2 335 17 9 9.5 5.2 | 7.0 44.6 345 9 5 10.3 5.7 10250 5.8 42.4 330 16 8 8.3 4.6 | 7.8 46.0 345 9 5 10.4 5.7 10000 6.2 43.2 330 15 8 6.9 3.8 | 8.6 47.5 345 9 4 10.6 5.8 9750 6.7 44.1 325 13 7 7.6 4.2 | 9.3 48.7 345 9 4 11.0 6.0 9500 7.2 45.0 320 11 6 9.4 5.2 | 10.2 50.4 345 8 4 9.9 5.4 9250 8.0 46.4 310 9 5 14.8 8.1 | 11.0 51.8 350 8 4 15.9 8.7 9000 9.5 49.1 305 6 3 32.3 17.7 | 13.5 56.3 345 7 3 68.2 37.4 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 05/13/2024 at 1500 MDT | 05/13/2024 at 1800 MDT | CAPE... +859.7 LI... -2.8 | CAPE... +1000.8 LI... -3.1 CINH... -0.3 K Index... +15.8 | CINH... -4.6 K Index... +18.2 | 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 -55.1 -67.2 260 15 8 3.9 2.1 | -55.4 -67.7 260 16 8 3.8 2.1 45000 -50.5 -58.9 275 16 8 -4.4 -2.4 | -51.2 -60.2 275 19 10 -5.0 -2.8 40000 -57.3 -71.1 300 17 9 -4.3 -2.3 | -58.9 -74.0 300 24 12 -4.7 -2.6 38000 -56.0 -68.8 320 19 10 4.5 2.5 | -57.1 -70.8 310 25 13 5.6 3.1 36000 -53.4 -64.1 340 24 12 4.5 2.5 | -53.8 -64.8 320 26 13 5.6 3.1 34000 -50.1 -58.2 350 27 14 7.2 3.9 | -49.9 -57.8 325 26 13 7.7 4.2 32000 -45.8 -50.4 350 24 12 7.1 3.9 | -45.3 -49.5 330 22 11 7.7 4.2 30000 -40.8 -41.4 350 23 12 7.7 4.2 | -40.2 -40.4 330 19 10 7.7 4.2 29000 -38.5 -37.3 355 23 12 7.7 4.2 | -37.9 -36.2 335 18 9 7.7 4.2 28000 -36.2 -33.2 355 23 12 7.7 4.2 | -35.6 -32.1 340 17 9 7.7 4.2 27000 -33.8 -28.8 355 23 12 8.2 4.5 | -33.2 -27.8 345 17 9 8.1 4.5 26000 -31.3 -24.3 355 24 12 8.2 4.5 | -30.8 -23.4 345 19 10 8.2 4.5 25000 -28.9 -20.0 355 25 13 8.2 4.5 | -28.3 -18.9 350 21 11 8.2 4.5 24000 -26.4 -15.5 355 26 13 8.1 4.5 | -25.9 -14.6 350 23 12 8.2 4.5 23000 -24.0 -11.2 355 27 14 8.1 4.5 | -23.4 -10.1 350 24 12 8.2 4.5 22000 -21.5 -6.7 350 28 14 8.1 4.5 | -21.0 -5.8 350 25 13 8.2 4.5 21000 -19.2 -2.6 350 28 14 7.8 4.3 | -18.5 -1.3 355 25 13 8.3 4.6 20000 -16.8 1.8 345 25 13 7.8 4.3 | -16.0 3.2 350 24 12 8.4 4.6 19500 -15.7 3.7 345 24 13 7.8 4.3 | -14.8 5.4 350 23 12 8.4 4.6 19000 -14.5 5.9 340 23 12 7.8 4.3 | -13.6 7.5 350 22 11 8.3 4.5 18500 -13.5 7.7 335 23 12 6.8 3.7 | -12.5 9.5 350 23 12 6.8 3.7 18000 -12.5 9.5 335 22 11 6.9 3.8 | -11.5 11.3 345 23 12 7.0 3.8 17500 -11.5 11.3 335 21 11 7.3 4.0 | -10.5 13.1 340 24 12 7.5 4.1 17000 -10.4 13.3 330 20 10 7.5 4.1 | -9.4 15.1 340 24 12 7.6 4.2 16500 -9.3 15.3 330 19 10 7.8 4.3 | -8.3 17.1 335 23 12 7.7 4.2 16000 -8.1 17.4 330 18 9 8.7 4.8 | -7.2 19.0 335 22 11 7.8 4.3 15500 -6.9 19.6 330 16 8 8.7 4.8 | -6.1 21.0 335 20 10 7.6 4.2 15000 -5.6 21.9 330 15 8 9.0 4.9 | -4.9 23.2 335 18 9 10.0 5.5 14500 -3.7 25.3 320 12 6 7.5 4.1 | -3.5 25.7 330 16 8 9.9 5.4 14000 -2.6 27.3 315 10 5 8.8 4.8 | -2.4 27.7 330 14 7 7.2 3.9 13500 -1.4 29.5 310 10 5 8.4 4.6 | -0.4 31.3 335 12 6 8.3 4.6 13000 -0.3 31.5 310 9 5 7.9 4.3 | 0.8 33.4 335 11 5 9.8 5.4 12500 0.9 33.6 305 9 5 8.4 4.6 | 2.3 36.1 335 9 5 10.5 5.8 12000 2.0 35.6 295 9 4 7.2 3.9 | 3.4 38.1 330 8 4 7.0 3.8 11750 2.6 36.7 295 9 4 8.0 4.4 | 4.1 39.4 330 7 4 10.2 5.6 11500 3.2 37.8 290 9 4 7.8 4.3 | 4.8 40.6 330 7 3 10.1 5.5 11250 3.7 38.7 285 9 4 8.1 4.4 | 5.6 42.1 325 6 3 9.1 5.0 11000 4.3 39.7 285 9 4 8.0 4.4 | 6.1 43.0 325 5 3 7.2 3.9 10750 4.9 40.8 280 9 4 9.1 5.0 | 6.7 44.1 325 4 2 8.6 4.7 10500 5.6 42.1 280 9 4 10.3 5.6 | 7.4 45.3 320 4 2 9.9 5.5 10250 6.4 43.5 275 9 4 9.9 5.4 | 8.1 46.6 315 3 2 9.4 5.1 10000 7.1 44.8 275 9 4 9.6 5.3 | 8.7 47.7 320 3 1 9.1 5.0 9750 7.8 46.0 270 8 4 10.1 5.5 | 9.4 48.9 320 2 1 9.3 5.1 9500 8.5 47.3 270 8 4 10.2 5.6 | 10.1 50.2 325 2 1 9.7 5.3 9250 9.4 48.9 270 8 4 16.3 9.0 | 10.9 51.6 325 1 1 12.6 6.9 9000 11.7 53.1 270 8 4 55.8 30.6 | 12.2 54.0 335 1 1 28.5 15.6 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 ________________________________________________________________________________ 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