![National Oceanic and Atmospheric Administration](/build/images/header/noaa.d87e0251.png)
![National Weather Service](/build/images/header/nws.4e6585d8.png)
![United States Department of Commerce](/build/images/header/doc.b38ba91a.png)
Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
162 UXUS97 KPUB 061216 SRGPUB Soaring Forecast National Weather Service Pueblo, Colorado 0616 MDT Saturday, July 6, 2024 This forecast is for Villa Grove, CO for Saturday, July 6, 2024: If the trigger temperature of 65.1 F/18.4 C is reached...then Thermal Soaring Index....................... Excellent Maximum rate of lift........................ 1586 ft/min (8.1 m/s) Maximum height of thermals.................. 24867 ft MSL (15903 ft AGL) Forecast maximum temperature................... 80.0 F/27.1 C Time of trigger temperature.................... 1015 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................. 20529 ft MSL (11565 ft AGL) Thermal soaring outlook for Sunday 07/07....... Excellent Wave Soaring Index............................. Not available Remarks... Sunrise/Sunset.................... 05:47:03 / 20:29:57 MDT Total possible sunshine........... 14 hr 42 min 55 sec (882 min 55 sec) Altitude of sun at 13:08:30 MDT... 74.20 degrees Upper air data from numerical model forecast valid on 07/06/2024 at 0600 MDT Freezing level.................. 15267 ft MSL (6303 ft AGL) Convective condensation level... 18921 ft MSL (9957 ft AGL) Lifted condensation level....... 21180 ft MSL (12216 ft AGL) Lifted index.................... -3.7 K index......................... -4.2 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 -60.3 -76.5 310 40 21 1.6 0.9 M M M M M 45000 -56.0 -68.8 300 52 27 5.3 2.9 M M M M M 40000 -48.4 -55.1 300 53 27 2.7 1.5 M M M M M 38000 -46.8 -52.2 300 48 25 2.7 1.5 M M M M M 36000 -45.2 -49.4 305 44 23 2.6 1.5 M M M M M 34000 -41.8 -43.2 305 41 21 6.6 3.6 M M M M M 32000 -37.9 -36.2 305 39 20 6.6 3.6 M M M M M 30000 -32.8 -27.0 305 34 18 7.8 4.3 31.0 87.9 3.5 M M 29000 -30.5 -22.9 310 32 17 7.8 4.3 30.3 86.6 2.9 M M 28000 -28.1 -18.6 310 30 15 7.3 4.0 29.7 85.5 2.5 M M 27000 -26.0 -14.8 315 28 14 7.0 3.9 28.6 83.5 1.6 M M 26000 -23.9 -11.0 315 26 14 7.0 3.9 27.6 81.7 0.8 M M 25000 -21.8 -7.2 320 25 13 7.1 3.9 26.7 80.1 0.1 M M 24000 -19.4 -2.9 320 24 12 8.3 4.5 26.1 78.9 -0.5 1493 7.6 23000 -16.9 1.6 320 24 12 8.3 4.5 25.5 78.0 -1.0 1390 7.1 22000 -14.5 5.9 315 24 12 7.8 4.3 25.1 77.2 -1.4 1286 6.5 21000 -12.5 9.5 310 24 12 6.3 3.4 23.9 75.0 -2.4 1198 6.1 20000 -10.7 12.7 305 24 12 6.3 3.5 22.7 72.9 -3.5 1113 5.7 19500 -9.7 14.5 305 24 12 6.4 3.5 22.2 71.9 -4.1 1070 5.4 19000 -8.9 16.0 300 24 12 5.5 3.0 21.6 70.8 -4.6 1029 5.2 18500 -8.1 17.4 295 23 12 5.6 3.1 20.9 69.6 -5.3 991 5.0 18000 -7.3 18.9 290 23 12 6.4 3.5 20.2 68.3 -6.0 952 4.8 17500 -6.2 20.8 285 22 11 7.7 4.2 19.8 67.7 -6.5 905 4.6 17000 -5.1 22.8 280 21 11 7.6 4.2 19.5 67.1 -6.8 857 4.4 16500 -3.8 25.2 280 21 11 9.5 5.2 19.3 66.7 -7.1 805 4.1 16000 -2.4 27.7 275 21 11 9.4 5.1 19.2 66.6 -7.2 748 3.8 15500 -1.0 30.2 270 21 11 9.6 5.3 19.2 66.5 -7.3 691 3.5 15000 0.5 32.9 270 21 11 9.7 5.3 19.2 66.5 -7.3 632 3.2 14500 2.5 36.5 270 21 11 8.0 4.4 19.0 66.2 -7.5 548 2.8 14000 3.9 39.0 270 20 10 9.2 5.0 18.9 66.1 -7.7 492 2.5 13500 5.3 41.5 270 19 10 10.0 5.5 18.9 66.0 -7.8 436 2.2 13000 6.5 43.7 270 18 9 7.3 4.0 18.7 65.7 -8.0 383 1.9 12500 7.6 45.7 270 17 9 7.8 4.3 18.4 65.1 -8.4 335 1.7 12000 8.8 47.8 265 16 8 7.3 4.0 18.2 64.7 -8.7 285 1.4 11750 9.3 48.7 265 16 8 6.5 3.6 17.9 64.2 -9.0 264 1.3 11500 9.7 49.5 260 15 8 4.8 2.6 17.6 63.7 -9.3 244 1.2 11250 9.9 49.8 255 15 8 2.6 1.4 17.1 62.8 -9.9 231 1.2 11000 10.0 50.0 250 16 8 2.9 1.6 16.6 61.9 -10.6 221 1.1 10750 10.1 50.2 245 16 8 3.0 1.7 16.1 60.9 -11.2 210 1.1 10500 10.2 50.4 240 16 8 1.9 1.0 15.5 60.0 -11.9 200 1.0 10250 10.2 50.4 240 16 8 1.0 0.6 14.9 58.8 -12.7 193 1.0 10000 10.1 50.2 235 15 8 0.2 0.1 14.2 57.6 -13.5 186 0.9 9750 10.1 50.2 230 15 8 3.4 1.9 13.5 56.4 -14.2 179 0.9 9500 10.2 50.4 230 15 8 -3.4 -1.9 13.0 55.4 -14.9 168 0.9 9250 9.2 48.6 230 10 5 -24.5 -13.4 11.2 52.2 -16.7 191 1.0 9000 8.1 46.6 230 6 3 11.4 6.2 9.3 48.7 -18.6 218 1.1 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 * * * * * * 07/06/2024 at 0900 MDT | 07/06/2024 at 1200 MDT | CAPE... +539.8 LI... -1.0 | CAPE... +176.1 LI... +0.6 CINH... -47.9 K Index... -8.9 | CINH... -7.3 K Index... -1.8 | 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 -60.1 -76.2 305 31 16 2.9 1.6 | -60.3 -76.5 295 34 17 3.1 1.7 45000 -54.8 -66.6 300 48 25 4.6 2.5 | -54.9 -66.8 300 50 26 4.1 2.3 40000 -48.2 -54.8 300 52 27 2.4 1.3 | -48.9 -56.0 305 57 29 2.6 1.4 38000 -46.7 -52.1 305 49 25 2.4 1.3 | -47.3 -53.1 310 55 28 2.6 1.4 36000 -45.2 -49.4 305 46 23 2.5 1.4 | -45.8 -50.4 315 54 28 2.6 1.4 34000 -42.1 -43.8 310 42 22 6.2 3.4 | -42.5 -44.5 315 49 25 6.2 3.4 32000 -38.3 -36.9 315 38 20 6.2 3.4 | -38.8 -37.8 310 44 23 6.3 3.4 30000 -33.5 -28.3 320 34 18 7.5 4.1 | -33.6 -28.5 310 40 21 8.2 4.5 29000 -31.2 -24.2 325 32 17 7.5 4.1 | -31.1 -24.0 310 39 20 8.2 4.5 28000 -29.0 -20.2 325 31 16 7.6 4.1 | -28.7 -19.7 310 38 19 8.1 4.4 27000 -26.7 -16.1 325 28 14 7.6 4.2 | -26.3 -15.3 310 36 18 8.0 4.4 26000 -24.4 -11.9 325 26 13 7.6 4.2 | -23.9 -11.0 310 33 17 8.0 4.4 25000 -22.2 -8.0 325 23 12 7.7 4.2 | -21.5 -6.7 310 31 16 8.0 4.4 24000 -19.6 -3.3 325 23 12 8.6 4.7 | -19.0 -2.2 305 27 14 8.3 4.5 23000 -17.0 1.4 325 22 12 8.6 4.7 | -16.5 2.3 305 22 11 8.3 4.5 22000 -14.5 5.9 325 22 11 8.2 4.5 | -14.1 6.6 305 17 9 7.8 4.3 21000 -12.3 9.9 320 22 11 7.0 3.9 | -12.0 10.4 300 19 10 6.8 3.7 20000 -10.2 13.6 310 22 12 7.1 3.9 | -10.0 14.0 300 22 11 6.8 3.7 19500 -9.1 15.6 310 23 12 7.5 4.1 | -9.0 15.8 295 23 12 7.0 3.9 19000 -8.3 17.1 305 23 12 2.9 1.6 | -8.1 17.4 295 24 12 4.1 2.3 18500 -7.9 17.8 295 22 12 3.4 1.8 | -7.5 18.5 290 25 13 4.4 2.4 18000 -7.4 18.7 290 22 12 5.2 2.8 | -6.9 19.6 285 25 13 5.6 3.1 17500 -6.4 20.5 285 23 12 8.1 4.4 | -5.8 21.6 280 24 12 7.9 4.3 17000 -5.2 22.6 280 23 12 8.2 4.5 | -4.7 23.5 275 22 11 8.2 4.5 16500 -4.0 24.8 280 23 12 9.2 5.0 | -3.5 25.7 270 21 11 8.7 4.8 16000 -2.7 27.1 280 23 12 9.2 5.0 | -2.2 28.0 270 20 10 8.7 4.8 15500 -1.4 29.5 280 23 12 9.2 5.0 | -1.0 30.2 270 19 10 9.2 5.0 15000 -0.0 32.0 280 22 11 9.1 5.0 | 0.4 32.7 270 17 9 9.4 5.1 14500 1.4 34.5 280 21 11 8.7 4.8 | 2.3 36.1 265 16 8 9.0 4.9 14000 3.4 38.1 280 21 11 9.3 5.1 | 3.8 38.8 265 15 8 10.1 5.5 13500 4.9 40.8 280 20 10 9.6 5.3 | 5.3 41.5 265 15 8 9.6 5.3 13000 6.2 43.2 275 19 10 8.1 4.4 | 6.7 44.1 260 14 7 10.0 5.5 12500 7.4 45.3 270 19 10 8.1 4.4 | 8.2 46.8 260 14 7 9.6 5.3 12000 8.5 47.3 265 18 9 7.2 4.0 | 9.6 49.3 260 14 7 10.1 5.5 11750 9.0 48.2 265 18 9 6.4 3.5 | 10.4 50.7 260 13 7 11.1 6.1 11500 9.4 48.9 260 18 9 5.1 2.8 | 11.2 52.2 260 13 7 10.1 5.5 11250 9.6 49.3 255 18 9 3.4 1.9 | 11.9 53.4 260 13 7 9.2 5.1 11000 9.8 49.6 250 17 9 3.8 2.1 | 12.6 54.7 255 13 7 9.1 5.0 10750 10.0 50.0 245 17 9 3.6 2.0 | 13.3 55.9 255 13 7 10.9 6.0 10500 10.2 50.4 240 16 8 5.7 3.1 | 14.1 57.4 255 13 6 11.7 6.4 10250 10.6 51.1 235 15 8 7.5 4.1 | 14.9 58.8 255 12 6 10.3 5.7 10000 11.1 52.0 230 14 7 8.0 4.4 | 15.7 60.3 255 12 6 10.9 6.0 9750 11.6 52.9 225 13 6 5.8 3.2 | 16.5 61.7 255 12 6 9.1 5.0 9500 12.1 53.8 220 12 6 11.8 6.5 | 17.3 63.1 255 11 6 15.9 8.7 9250 13.5 56.3 220 10 5 28.5 15.7 | 19.1 66.4 250 10 5 33.4 18.3 9000 15.1 59.2 220 9 4 -1.4 -0.8 | 21.1 70.0 250 10 5 8.5 4.7 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 07/06/2024 at 1500 MDT | 07/06/2024 at 1800 MDT | CAPE... +2.0 LI... +1.1 | CAPE... +0.7 LI... +1.6 CINH... -3.4 K Index... -10.3 | CINH... -35.2 K Index... -1.6 | 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 -60.4 -76.7 290 37 19 2.4 1.3 | -59.7 -75.5 290 36 19 2.8 1.5 45000 -56.2 -69.2 295 51 26 3.9 2.2 | -55.3 -67.5 295 51 26 2.7 1.5 40000 -50.0 -58.0 305 58 30 3.6 2.0 | -51.0 -59.8 305 60 31 4.5 2.5 38000 -47.9 -54.2 305 58 30 3.6 2.0 | -48.3 -54.9 305 60 31 4.5 2.5 36000 -45.7 -50.3 305 57 29 3.5 1.9 | -45.6 -50.1 310 59 31 4.5 2.5 34000 -42.3 -44.1 305 53 27 6.2 3.4 | -42.0 -43.6 310 56 29 6.3 3.5 32000 -38.6 -37.5 305 48 25 6.3 3.4 | -38.2 -36.8 315 53 27 6.4 3.5 30000 -34.0 -29.2 305 44 23 8.2 4.5 | -33.3 -27.9 315 47 24 7.6 4.2 29000 -31.0 -23.8 305 43 22 8.2 4.5 | -31.0 -23.8 315 44 23 7.6 4.2 28000 -28.5 -19.3 305 41 21 8.5 4.6 | -28.7 -19.7 310 41 21 8.7 4.8 27000 -25.9 -14.6 305 40 20 8.5 4.7 | -26.0 -14.8 305 39 20 9.1 5.0 26000 -23.4 -10.1 305 38 19 8.5 4.7 | -23.2 -9.8 300 37 19 9.1 5.0 25000 -20.8 -5.4 305 36 19 8.3 4.5 | -20.5 -4.9 295 35 18 8.8 4.8 24000 -18.7 -1.7 300 34 17 7.9 3.8 | -18.2 -0.8 300 34 18 7.6 4.1 23000 -16.6 2.1 295 31 16 7.0 3.8 | -15.9 3.4 305 33 17 7.6 4.1 22000 -14.5 5.9 290 29 15 7.2 3.9 | -13.7 7.3 310 33 17 7.5 4.1 21000 -12.2 10.0 285 28 14 7.7 4.2 | -11.4 11.5 310 29 15 7.5 4.1 20000 -9.9 14.2 285 26 13 7.7 4.2 | -9.2 15.4 310 25 13 7.5 4.1 19500 -8.7 16.3 285 25 13 7.7 4.2 | -8.1 17.4 310 23 12 7.5 4.1 19000 -7.6 18.3 280 25 13 7.3 4.0 | -7.0 19.4 310 22 11 6.9 3.8 18500 -6.5 20.3 280 24 12 7.4 4.1 | -6.0 21.2 305 20 10 7.0 3.8 18000 -5.4 22.3 275 24 12 7.7 4.2 | -5.0 23.0 305 18 9 7.4 4.0 17500 -4.3 24.3 275 23 12 8.1 4.4 | -3.8 25.2 305 18 9 8.0 4.4 17000 -3.1 26.4 270 22 11 8.2 4.5 | -2.7 27.1 305 17 9 8.0 4.4 16500 -1.9 28.6 270 21 11 9.1 5.0 | -1.5 29.3 305 18 9 8.4 4.6 16000 -0.6 30.9 270 21 11 9.1 5.0 | -0.2 31.6 300 19 10 8.4 4.6 15500 0.7 33.3 270 21 11 9.4 5.2 | 1.0 33.8 300 20 10 8.7 4.7 15000 2.8 37.0 270 20 11 9.5 5.2 | 2.3 36.1 300 21 11 8.9 4.9 14500 4.3 39.7 270 20 10 10.1 5.5 | 4.2 39.6 295 23 12 9.6 5.3 14000 5.7 42.3 270 20 10 9.8 5.4 | 5.6 42.1 290 23 12 9.5 5.2 13500 7.2 45.0 270 20 10 9.2 5.0 | 7.0 44.6 290 23 12 8.6 4.7 13000 8.6 47.5 270 20 10 10.2 5.6 | 8.4 47.1 290 23 12 10.6 5.8 12500 10.1 50.2 270 20 10 9.9 5.5 | 10.0 50.0 290 23 12 9.5 5.2 12000 11.6 52.9 270 20 10 10.3 5.7 | 11.3 52.3 290 22 12 9.8 5.4 11750 12.4 54.3 270 20 10 11.0 6.1 | 12.1 53.8 290 22 11 11.6 6.4 11500 13.2 55.8 270 19 10 10.3 5.7 | 12.9 55.2 290 22 11 10.7 5.9 11250 13.9 57.0 270 19 10 9.4 5.2 | 13.7 56.7 290 22 11 10.0 5.5 11000 14.6 58.3 270 19 10 9.3 5.1 | 14.4 57.9 290 22 11 9.7 5.3 10750 15.3 59.5 270 19 10 10.4 5.7 | 15.1 59.2 290 22 11 10.4 5.7 10500 16.2 61.2 270 19 10 11.3 6.2 | 15.9 60.6 290 21 11 10.6 5.8 10250 17.0 62.6 270 19 10 10.9 6.0 | 16.7 62.1 290 21 11 10.2 5.6 10000 17.8 64.0 270 18 9 11.4 6.3 | 17.5 63.5 290 20 11 10.2 5.6 9750 18.6 65.5 270 18 9 9.7 5.3 | 18.2 64.8 290 20 10 10.0 5.5 9500 19.4 66.9 270 17 9 14.5 7.9 | 19.0 66.2 290 19 10 12.6 6.9 9250 21.0 69.8 270 16 8 30.5 16.7 | 20.2 68.4 290 17 9 19.2 10.5 9000 23.3 73.9 270 14 7 22.7 12.4 | 21.6 70.9 285 14 7 16.6 9.1 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