Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
569 UXUS97 KPUB 031218 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0618 MDT Friday, May 3, 2024 This forecast is for Villa Grove, CO for Friday, May 3, 2024: If the trigger temperature of 46.6 F/8.1 C is reached...then Thermal Soaring Index....................... Good Maximum rate of lift........................ 1622 ft/min (8.2 m/s) Maximum height of thermals.................. 25627 ft MSL (16654 ft AGL) Forecast maximum temperature................... 65.0 F/18.8 C Time of trigger temperature.................... 0845 MDT Time of overdevelopment........................ 1500 MDT Middle/high clouds during soaring window....... None Surface winds during soaring window............ Between 20 mph and 30 mph Height of the -3 thermal index................. 20732 ft MSL (11758 ft AGL) Thermal soaring outlook for Saturday 05/04..... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 06:03:35 / 19:57:11 MDT Total possible sunshine........... 13 hr 53 min 35 sec (833 min 35 sec) Altitude of sun at 13:00:23 MDT... 67.72 degrees Upper air data from numerical model forecast valid on 05/03/2024 at 0600 MDT Freezing level.................. 9060 ft MSL (87 ft AGL) Additional freezing level....... 11604 ft MSL (2631 ft AGL) Convective condensation level... 18849 ft MSL (9876 ft AGL) Lifted condensation level....... 21307 ft MSL (12334 ft AGL) Lifted index.................... -2.4 K index......................... -0.3 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 -55.2 -67.4 250 42 21 0.8 0.5 M M M M M 45000 -54.0 -65.2 250 40 20 -2.7 -1.5 M M M M M 40000 -59.2 -74.6 260 63 33 -3.5 -1.9 M M M M M 38000 -58.3 -72.9 265 67 35 5.6 3.1 M M M M M 36000 -54.9 -66.8 265 66 34 5.7 3.1 M M M M M 34000 -51.3 -60.3 265 64 33 6.8 3.8 M M M M M 32000 -46.7 -52.1 260 61 32 6.8 3.7 M M M M M 30000 -42.5 -44.5 260 59 30 7.7 4.2 21.4 70.6 2.4 M M 29000 -40.2 -40.4 260 58 30 7.7 4.2 20.6 69.1 1.8 M M 28000 -37.9 -36.2 260 56 29 7.7 4.2 19.9 67.8 1.2 M M 27000 -35.5 -31.9 255 55 29 8.1 4.4 19.3 66.7 0.7 M M 26000 -33.1 -27.6 255 56 29 8.2 4.5 18.6 65.4 0.2 M M 25000 -30.6 -23.1 255 57 29 8.2 4.5 18.0 64.4 -0.3 1554 7.9 24000 -28.2 -18.8 255 57 30 8.0 4.4 17.5 63.6 -0.7 1451 7.4 23000 -25.8 -14.4 255 56 29 7.8 4.3 16.8 62.2 -1.4 1351 6.9 22000 -23.5 -10.3 255 55 28 7.8 4.3 16.1 61.0 -2.0 1252 6.4 21000 -21.2 -6.2 255 52 27 6.2 3.4 15.4 59.7 -2.6 1154 5.9 20000 -19.5 -3.1 250 43 22 5.9 3.3 14.0 57.2 -3.9 1072 5.4 19500 -18.6 -1.5 245 38 20 5.9 3.3 13.4 56.1 -4.5 1030 5.2 19000 -17.7 0.1 245 34 17 5.9 3.3 12.8 55.0 -5.0 989 5.0 18500 -16.8 1.8 240 30 15 6.0 3.3 12.2 53.9 -5.6 948 4.8 18000 -15.9 3.4 245 32 17 6.0 3.3 11.5 52.8 -6.2 907 4.6 17500 -15.1 4.8 250 35 18 6.1 3.3 10.9 51.7 -6.8 865 4.4 17000 -14.1 6.6 255 37 19 6.8 3.7 10.4 50.7 -7.4 822 4.2 16500 -13.1 8.4 260 40 20 6.7 3.7 9.9 49.8 -8.0 778 4.0 16000 -12.1 10.2 260 41 21 8.0 4.4 9.5 49.0 -8.4 733 3.7 15500 -10.9 12.4 260 39 20 8.4 4.6 9.2 48.6 -8.7 682 3.5 15000 -8.9 16.0 260 36 19 10.3 5.7 9.0 48.3 -9.0 600 3.0 14500 -7.4 18.7 260 33 17 8.0 4.4 9.1 48.4 -9.0 540 2.7 14000 -6.4 20.5 255 31 16 8.9 4.9 8.7 47.6 -9.5 494 2.5 13500 -5.0 23.0 255 30 15 9.6 5.3 8.6 47.5 -9.6 437 2.2 13000 -3.7 25.3 250 29 15 8.6 4.7 8.5 47.2 -9.8 383 1.9 12500 -2.3 27.9 250 28 14 9.3 5.1 8.4 47.1 -10.0 327 1.7 12000 -0.9 30.4 250 27 14 8.9 4.9 8.3 46.9 -10.1 271 1.4 11750 -0.2 31.6 245 27 14 9.1 5.0 8.2 46.8 -10.2 243 1.2 11500 0.5 32.9 245 27 14 9.4 5.2 8.2 46.8 -10.2 215 1.1 11250 1.2 34.2 245 27 14 9.3 5.1 8.2 46.7 -10.3 186 0.9 11000 1.9 35.4 245 27 14 8.8 4.8 8.1 46.6 -10.4 158 0.8 10750 2.5 36.5 245 26 13 6.6 3.6 8.0 46.4 -10.5 133 0.7 10500 2.9 37.2 240 25 13 5.2 2.9 7.7 45.8 -10.8 112 0.6 10250 3.3 37.9 240 24 12 5.0 2.8 7.3 45.2 -11.2 93 0.5 10000 3.5 38.3 235 22 12 -3.3 -1.8 6.8 44.2 -11.8 81 0.4 9750 2.9 37.2 235 20 10 -9.7 -5.3 5.4 41.7 -13.2 92 0.5 9500 2.3 36.1 225 17 9 -6.2 -3.4 4.1 39.3 -14.5 102 0.5 9250 1.6 34.9 220 14 7 -14.0 -7.7 2.7 36.9 -15.9 113 0.6 9000 -0.9 30.4 210 5 3 -62.5 -34.3 -0.5 31.0 -19.2 182 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 * * * * * * 05/03/2024 at 0900 MDT | 05/03/2024 at 1200 MDT | CAPE... 0.0 LI... +2.3 | CAPE... +35.1 LI... +0.1 CINH... 0.0 K Index... -3.2 | CINH... 0.0 K Index... +8.0 | 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 -55.0 -67.0 250 41 21 0.3 0.2 | -55.3 -67.5 245 39 20 0.3 0.2 45000 -54.7 -66.5 250 41 21 -2.8 -1.5 | -55.1 -67.2 250 49 25 -2.7 -1.5 40000 -59.8 -75.6 260 60 31 -3.4 -1.9 | -60.0 -76.0 255 59 30 -3.3 -1.8 38000 -58.5 -73.3 260 62 32 6.3 3.4 | -58.5 -73.3 255 60 31 6.7 3.7 36000 -54.7 -66.5 260 59 30 6.3 3.4 | -54.5 -66.1 255 59 30 6.7 3.7 34000 -50.9 -59.6 260 56 29 6.8 3.8 | -50.1 -58.2 255 56 29 6.5 3.6 32000 -46.3 -51.3 260 52 27 6.8 3.7 | -46.1 -51.0 255 50 26 6.5 3.6 30000 -41.9 -43.4 255 50 26 8.0 4.4 | -41.8 -43.2 250 47 24 8.2 4.5 29000 -39.6 -39.3 255 51 26 8.0 4.4 | -39.4 -38.9 250 47 24 8.2 4.5 28000 -37.2 -35.0 250 52 27 8.0 4.4 | -36.9 -34.4 250 47 24 8.2 4.5 27000 -34.8 -30.6 250 52 27 7.7 4.2 | -34.4 -29.9 250 47 24 8.0 4.4 26000 -32.5 -26.5 250 53 27 7.6 4.2 | -32.0 -25.6 250 47 24 8.0 4.4 25000 -30.2 -22.4 250 53 27 7.6 4.2 | -29.6 -21.3 250 48 24 8.0 4.4 24000 -27.9 -18.2 245 53 27 7.7 4.2 | -27.2 -17.0 250 48 25 7.5 4.1 23000 -25.6 -14.1 245 52 27 7.8 4.3 | -25.1 -13.2 250 47 24 7.2 4.0 22000 -23.2 -9.8 250 52 27 7.8 4.3 | -22.9 -9.2 250 47 24 7.2 4.0 21000 -21.0 -5.8 250 50 26 6.5 3.6 | -20.8 -5.4 245 46 24 5.8 3.2 20000 -19.1 -2.4 245 43 22 6.4 3.5 | -19.1 -2.4 250 42 22 5.8 3.2 19500 -18.1 -0.6 245 40 20 6.4 3.5 | -18.3 -0.9 250 40 21 5.8 3.2 19000 -17.2 1.0 245 37 19 6.4 3.5 | -17.4 0.7 250 38 19 5.8 3.2 18500 -16.2 2.8 245 34 17 5.8 3.2 | -16.5 2.3 250 36 18 6.2 3.4 18000 -15.4 4.3 245 36 18 5.5 3.0 | -15.6 3.9 250 34 18 6.5 3.6 17500 -14.6 5.7 250 38 20 5.5 3.0 | -14.7 5.5 250 33 17 6.8 3.7 17000 -13.9 7.0 250 39 20 5.2 2.9 | -13.6 7.5 250 31 16 8.3 4.5 16500 -13.1 8.4 250 41 21 5.2 2.8 | -12.4 9.7 250 30 15 8.1 4.5 16000 -11.6 11.1 255 40 21 9.0 4.9 | -10.4 13.3 245 28 14 9.4 5.2 15500 -10.2 13.6 255 38 20 8.6 4.7 | -9.0 15.8 245 27 14 9.3 5.1 15000 -8.7 16.3 255 36 19 11.1 6.1 | -7.5 18.5 240 27 14 11.4 6.3 14500 -7.1 19.2 250 34 18 8.3 4.6 | -5.7 21.7 240 26 13 8.1 4.5 14000 -6.1 21.0 250 32 17 9.1 5.0 | -4.6 23.7 240 26 13 10.3 5.7 13500 -4.6 23.7 250 30 16 9.6 5.3 | -3.1 26.4 240 26 13 10.8 5.9 13000 -3.3 26.1 250 28 15 8.6 4.7 | -1.8 28.8 235 25 13 8.1 4.4 12500 -2.0 28.4 250 28 14 8.9 4.9 | -0.3 31.5 235 25 13 10.1 5.6 12000 -0.7 30.7 250 27 14 8.2 4.5 | 1.2 34.2 235 25 13 9.4 5.1 11750 -0.1 31.8 245 27 14 7.9 4.3 | 1.9 35.4 235 24 13 10.3 5.6 11500 0.5 32.9 245 26 13 8.2 4.5 | 2.7 36.9 235 24 12 10.5 5.7 11250 1.1 34.0 245 26 13 8.1 4.4 | 3.5 38.3 235 24 12 10.5 5.7 11000 1.7 35.1 240 26 13 6.7 3.7 | 4.2 39.6 235 24 12 9.8 5.4 10750 2.1 35.8 240 25 13 4.9 2.7 | 5.0 41.0 235 24 12 9.9 5.4 10500 2.5 36.5 240 24 12 4.4 2.4 | 5.7 42.3 230 23 12 10.4 5.7 10250 2.8 37.0 235 22 12 4.5 2.5 | 6.5 43.7 230 23 12 10.3 5.7 10000 3.2 37.8 235 21 11 5.3 2.9 | 7.3 45.1 230 23 12 11.1 6.1 9750 3.6 38.5 230 18 9 6.5 3.6 | 8.2 46.8 230 22 11 12.2 6.7 9500 4.2 39.6 230 15 8 8.5 4.7 | 9.1 48.4 230 21 11 10.1 5.6 9250 5.0 41.0 225 13 6 16.5 9.0 | 9.9 49.8 230 20 10 16.9 9.3 9000 7.0 44.6 225 10 5 42.0 23.0 | 12.9 55.2 230 16 8 79.6 43.7 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 05/03/2024 at 1500 MDT | 05/03/2024 at 1800 MDT | CAPE... +42.4 LI... -0.5 | CAPE... +14.3 LI... -0.1 CINH... -3.9 K Index... +19.9 | CINH... -14.5 K Index... +19.9 | 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 -56.1 -69.0 250 40 20 0.1 0.1 | -56.3 -69.3 255 39 20 -0.4 -0.2 45000 -56.0 -68.8 250 53 27 -2.4 -1.3 | -56.9 -70.4 255 47 24 -1.5 -0.8 40000 -60.0 -76.0 250 61 32 -2.7 -1.5 | -59.5 -75.1 255 55 28 -1.6 -0.9 38000 -58.4 -73.1 255 63 32 6.4 3.5 | -57.6 -71.7 255 57 29 5.6 3.1 36000 -54.6 -66.3 255 64 33 6.4 3.5 | -54.2 -65.6 255 59 30 5.6 3.1 34000 -50.1 -58.2 255 62 32 7.2 3.9 | -50.5 -58.9 255 59 31 7.9 4.3 32000 -45.8 -50.4 255 57 29 7.2 3.9 | -45.7 -50.3 255 57 29 7.9 4.3 30000 -41.4 -42.5 250 52 27 7.4 4.1 | -41.2 -42.2 255 54 28 6.8 3.7 29000 -39.2 -38.6 250 50 26 7.4 4.1 | -39.2 -38.6 255 52 27 6.7 3.7 28000 -37.0 -34.6 250 48 25 7.4 4.1 | -37.2 -35.0 260 50 26 6.7 3.7 27000 -34.7 -30.5 250 47 24 7.7 4.2 | -34.6 -30.3 260 47 24 8.2 4.5 26000 -32.4 -26.3 255 46 23 7.7 4.2 | -32.2 -26.0 260 45 23 8.1 4.4 25000 -30.1 -22.2 255 44 23 7.7 4.2 | -29.7 -21.5 260 43 22 8.1 4.4 24000 -27.8 -18.0 255 43 22 7.0 3.8 | -27.4 -17.3 255 41 21 6.8 3.7 23000 -25.8 -14.4 255 42 22 6.6 3.6 | -25.4 -13.7 255 38 19 6.7 3.7 22000 -23.8 -10.8 255 41 21 6.7 3.7 | -23.5 -10.3 250 35 18 6.7 3.7 21000 -21.8 -7.2 250 40 20 8.1 4.5 | -21.4 -6.5 250 32 17 8.3 4.6 20000 -19.4 -2.9 250 35 18 8.2 4.5 | -19.0 -2.2 245 29 15 8.3 4.5 19500 -18.2 -0.8 250 32 17 8.2 4.5 | -17.8 -0.0 245 28 14 8.3 4.6 19000 -17.0 1.4 245 30 15 8.3 4.5 | -16.6 2.1 245 26 14 8.4 4.6 18500 -15.8 3.6 245 28 14 8.7 4.8 | -15.4 4.3 240 25 13 8.2 4.5 18000 -14.5 5.9 245 26 14 8.8 4.8 | -14.2 6.4 245 25 13 8.2 4.5 17500 -13.2 8.2 245 25 13 8.5 4.7 | -13.0 8.6 245 24 13 8.0 4.4 17000 -12.1 10.2 245 24 12 7.2 4.0 | -11.8 10.8 245 24 12 7.7 4.2 16500 -11.0 12.2 245 23 12 7.1 3.9 | -10.7 12.7 250 23 12 7.6 4.2 16000 -9.0 15.8 245 22 12 9.7 5.3 | -9.4 15.1 250 22 11 9.1 5.0 15500 -7.6 18.3 240 22 11 9.7 5.3 | -8.1 17.4 255 20 11 8.9 4.9 15000 -6.0 21.2 240 22 11 11.1 6.1 | -6.7 19.9 255 20 10 10.8 5.9 14500 -4.4 24.1 240 22 11 7.8 4.3 | -5.0 23.0 255 20 10 11.5 6.3 14000 -3.2 26.2 240 22 11 10.5 5.7 | -3.1 26.4 255 19 10 10.3 5.6 13500 -1.7 28.9 240 22 11 10.8 5.9 | -1.6 29.1 260 19 10 9.9 5.4 13000 -0.3 31.5 240 22 11 8.5 4.6 | -0.1 31.8 260 19 10 9.7 5.3 12500 1.2 34.2 240 22 11 10.1 5.5 | 1.3 34.3 260 19 10 10.0 5.5 12000 2.6 36.7 240 22 11 9.2 5.0 | 2.6 36.7 260 18 9 8.4 4.6 11750 3.4 38.1 240 21 11 10.5 5.7 | 3.3 37.9 260 18 9 10.7 5.9 11500 4.1 39.4 240 21 11 10.5 5.8 | 4.1 39.4 260 18 9 10.3 5.7 11250 4.9 40.8 240 21 11 10.6 5.8 | 4.9 40.8 260 18 9 10.4 5.7 11000 5.7 42.3 240 21 11 9.8 5.4 | 5.6 42.1 260 18 9 9.1 5.0 10750 6.4 43.5 240 21 11 9.7 5.3 | 6.3 43.3 260 18 9 9.5 5.2 10500 7.2 45.0 240 21 11 10.3 5.7 | 7.1 44.8 260 17 9 10.6 5.8 10250 8.0 46.4 240 20 10 10.2 5.6 | 7.8 46.0 260 17 9 10.3 5.6 10000 8.7 47.7 240 20 10 10.2 5.6 | 8.6 47.5 260 17 9 9.8 5.4 9750 9.5 49.1 235 19 10 10.3 5.7 | 9.3 48.7 260 16 8 9.4 5.2 9500 10.2 50.4 235 19 10 9.7 5.3 | 10.0 50.0 260 15 8 9.5 5.2 9250 11.0 51.8 235 17 9 12.4 6.8 | 10.7 51.3 260 14 7 10.5 5.7 9000 12.6 54.7 235 14 7 36.1 19.8 | 11.7 53.1 260 11 6 18.6 10.2 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