Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
327
UXUS97 KPUB 101215
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0614 MDT Sunday, August 10, 2025
This forecast is for Villa Grove, CO for Sunday, August 10, 2025:
If the trigger temperature of 63.9 F/17.7 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 1492 ft/min (7.6 m/s)
Maximum height of thermals.................. 22205 ft MSL (13243 ft AGL)
Forecast maximum temperature................... 77.0 F/25.5 C
Time of trigger temperature.................... 0900 MDT
Time of overdevelopment........................ 1300 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 18747 ft MSL (9785 ft AGL)
Thermal soaring outlook for Monday 08/11....... Excellent
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 06:14:28 / 20:03:17 MDT
Total possible sunshine........... 13 hr 48 min 49 sec (828 min 49 sec)
Altitude of sun at 13:08:52 MDT... 66.96 degrees
Upper air data from numerical model forecast valid on 08/10/2025 at 0600 MDT
Freezing level.................. 15198 ft MSL (6236 ft AGL)
Convective condensation level... 13466 ft MSL (4504 ft AGL)
Lifted condensation level....... 16237 ft MSL (7275 ft AGL)
Lifted index.................... -9.6
K index......................... +26.0
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 -61.2 -78.2 220 15 8 -1.3 -0.7 M M M M M
45000 -61.4 -78.5 220 35 18 3.2 1.7 M M M M M
40000 -56.1 -69.0 230 47 24 8.1 4.4 M M M M M
38000 -51.3 -60.3 230 45 23 7.9 4.4 M M M M M
36000 -46.5 -51.7 235 44 23 7.9 4.4 M M M M M
34000 -41.8 -43.2 240 43 22 7.9 4.3 M M M M M
32000 -37.1 -34.8 245 42 21 7.9 4.3 M M M M M
30000 -32.0 -25.6 255 41 21 7.5 4.1 32.0 89.7 5.5 M M
29000 -29.7 -21.5 255 40 21 7.5 4.1 31.2 88.2 5.0 M M
28000 -27.5 -17.5 260 40 21 7.2 4.0 30.5 87.0 4.4 M M
27000 -25.4 -13.7 260 39 20 7.1 3.9 29.4 85.0 3.5 M M
26000 -23.3 -9.9 265 38 20 7.1 3.9 28.4 83.2 2.7 M M
25000 -21.2 -6.2 265 38 19 7.2 3.9 27.6 81.7 2.0 M M
24000 -19.0 -2.2 265 36 19 7.5 4.1 26.7 80.1 1.2 M M
23000 -16.8 1.8 265 35 18 7.6 4.2 25.9 78.7 0.5 M M
22000 -14.6 5.7 265 34 17 7.5 4.1 25.3 77.5 -0.1 1273 6.5
21000 -12.5 9.5 265 32 17 7.2 3.9 24.3 75.8 -1.0 1181 6.0
20000 -10.4 13.3 265 31 16 7.2 3.9 23.5 74.2 -1.9 1089 5.5
19500 -9.4 15.1 260 30 16 7.2 4.0 23.1 73.5 -2.3 1043 5.3
19000 -8.3 17.1 265 30 15 7.0 3.8 22.6 72.7 -2.7 997 5.1
18500 -7.3 18.9 265 28 15 7.0 3.8 22.2 71.9 -3.2 952 4.8
18000 -6.3 20.7 265 27 14 6.6 3.6 21.7 71.1 -3.6 907 4.6
17500 -5.5 22.1 270 26 13 5.9 3.2 21.1 70.0 -4.3 866 4.4
17000 -4.6 23.7 275 25 13 5.7 3.1 20.5 68.9 -4.9 825 4.2
16500 -3.6 25.5 275 23 12 8.2 4.5 20.0 68.0 -5.3 780 4.0
16000 -2.4 27.7 280 21 11 8.0 4.4 19.7 67.5 -5.6 729 3.7
15500 -1.1 30.0 285 19 10 8.6 4.7 19.5 67.0 -5.9 678 3.4
15000 0.2 32.4 290 17 9 8.9 4.9 19.3 66.8 -6.0 622 3.2
14500 2.2 36.0 290 15 7 9.4 5.1 19.2 66.5 -6.2 539 2.7
14000 3.6 38.5 290 13 7 9.6 5.3 19.1 66.4 -6.3 482 2.5
13500 5.0 41.0 290 11 6 7.8 4.3 19.1 66.3 -6.5 428 2.2
13000 6.0 42.8 280 7 4 8.4 4.6 18.7 65.7 -7.0 383 1.9
12500 7.0 44.6 250 4 2 7.8 4.3 18.5 65.4 -7.5 337 1.7
12000 7.9 46.2 185 3 1 7.0 3.8 18.1 64.6 -8.1 296 1.5
11750 8.3 46.9 155 3 2 7.0 3.9 17.9 64.2 -8.4 276 1.4
11500 8.7 47.7 140 5 2 6.3 3.4 17.7 63.8 -8.8 256 1.3
11250 9.1 48.4 130 6 3 5.1 2.8 17.4 63.2 -9.2 239 1.2
11000 9.4 48.9 120 6 3 5.1 2.8 17.0 62.6 -9.6 221 1.1
10750 9.7 49.5 115 7 4 5.4 3.0 16.7 62.0 -10.0 204 1.0
10500 10.1 50.2 110 8 4 4.7 2.6 16.3 61.4 -10.4 186 0.9
10250 10.3 50.5 105 8 4 3.6 2.0 15.9 60.6 -10.9 170 0.9
10000 10.6 51.1 100 8 4 3.3 1.8 15.4 59.7 -11.4 155 0.8
9750 10.9 51.6 095 7 4 4.6 2.5 14.9 58.9 -11.9 140 0.7
9500 11.2 52.2 085 7 4 4.0 2.2 14.6 58.3 -12.3 122 0.6
9250 11.4 52.5 080 5 2 -1.2 -0.7 14.0 57.1 -12.9 109 0.6
9000 11.5 52.7 060 2 1 6.8 3.7 13.3 55.9 -13.5 98 0.5
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 * * * * * *
08/10/2025 at 0900 MDT | 08/10/2025 at 1200 MDT
|
CAPE... +2138.4 LI... -6.0 | CAPE... +801.2 LI... -2.3
CINH... -0.4 K Index... +25.7 | CINH... -4.1 K Index... +26.6
|
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 -76.7 230 13 7 -0.4 -0.2 | -58.6 -73.5 285 10 5 1.1 0.6
45000 -60.0 -76.0 235 31 16 2.2 1.2 | -57.2 -71.0 275 19 10 0.2 0.1
40000 -56.2 -69.2 245 51 26 7.1 3.9 | -56.5 -69.7 255 31 16 6.2 3.4
38000 -52.2 -62.0 245 50 26 6.7 3.7 | -52.9 -63.2 245 35 18 5.9 3.2
36000 -48.1 -54.6 240 48 25 6.7 3.7 | -49.4 -56.9 240 41 21 6.0 3.3
34000 -43.5 -46.3 240 46 24 8.1 4.4 | -44.0 -47.2 240 41 21 8.6 4.7
32000 -38.0 -36.4 245 43 22 8.0 4.4 | -38.8 -37.8 240 39 20 8.6 4.7
30000 -33.2 -27.8 250 39 20 8.1 4.5 | -33.9 -29.0 240 38 20 8.2 4.5
29000 -30.7 -23.3 250 37 19 8.2 4.5 | -31.4 -24.5 240 38 19 8.2 4.5
28000 -28.3 -18.9 255 36 18 7.9 4.3 | -28.9 -20.0 240 37 19 7.9 4.3
27000 -26.0 -14.8 255 34 18 7.8 4.3 | -26.7 -16.1 245 38 20 7.7 4.2
26000 -23.7 -10.7 260 33 17 7.9 4.3 | -24.4 -11.9 245 39 20 7.7 4.2
25000 -21.4 -6.5 260 32 16 7.9 4.3 | -22.1 -7.8 250 40 21 7.7 4.2
24000 -19.1 -2.4 265 32 16 7.8 4.3 | -20.0 -4.0 255 41 21 6.8 3.7
23000 -16.8 1.8 265 31 16 7.8 4.3 | -18.0 -0.4 260 41 21 6.8 3.7
22000 -14.5 5.9 270 31 16 7.5 4.1 | -16.0 3.2 265 41 21 7.1 3.9
21000 -12.6 9.3 270 31 16 6.3 3.5 | -13.7 7.3 275 41 21 8.0 4.4
20000 -10.8 12.6 270 30 15 6.4 3.5 | -11.4 11.5 280 40 21 8.1 4.4
19500 -9.8 14.4 270 30 15 6.3 3.5 | -10.3 13.5 280 40 21 8.2 4.5
19000 -8.9 16.0 265 29 15 7.0 3.8 | -9.2 15.4 285 40 21 6.7 3.7
18500 -7.9 17.8 265 29 15 7.0 3.8 | -8.2 17.2 285 39 20 6.8 3.7
18000 -6.9 19.6 270 28 14 6.8 3.7 | -6.6 20.1 285 37 19 7.9 4.3
17500 -5.9 21.4 270 27 14 6.4 3.5 | -5.4 22.3 280 35 18 8.0 4.4
17000 -5.0 23.0 270 26 14 6.3 3.5 | -4.3 24.3 280 33 17 8.3 4.6
16500 -3.5 25.7 270 25 13 7.0 3.8 | -3.0 26.6 275 31 16 8.8 4.8
16000 -2.5 27.5 270 24 13 7.0 3.9 | -1.7 28.9 270 28 15 8.8 4.8
15500 -1.3 29.7 270 24 12 8.4 4.6 | -0.3 31.5 265 27 14 9.5 5.2
15000 -0.1 31.8 275 23 12 8.0 4.4 | 1.1 34.0 265 26 13 9.4 5.2
14500 1.2 34.2 275 22 11 9.2 5.1 | 2.5 36.5 260 24 12 9.2 5.1
14000 2.5 36.5 275 20 11 8.3 4.5 | 3.7 38.7 250 22 11 8.6 4.7
13500 3.7 38.7 280 19 10 10.3 5.7 | 5.0 41.0 245 20 11 9.4 5.2
13000 5.0 41.0 280 17 9 7.1 3.9 | 6.2 43.2 235 18 9 7.7 4.2
12500 6.1 43.0 280 15 8 7.7 4.2 | 7.3 45.1 225 16 8 9.3 5.1
12000 7.2 45.0 275 13 6 7.9 4.3 | 8.9 48.0 220 14 7 9.6 5.3
11750 7.7 45.9 270 12 6 7.8 4.3 | 9.6 49.3 215 14 7 8.1 4.5
11500 8.2 46.8 270 11 5 7.9 4.3 | 10.2 50.4 215 14 7 9.2 5.1
11250 8.7 47.7 265 9 5 7.9 4.3 | 10.9 51.6 215 13 7 10.1 5.5
11000 9.2 48.6 255 8 4 8.2 4.5 | 11.7 53.1 215 13 7 10.2 5.6
10750 9.7 49.5 240 7 3 7.5 4.1 | 12.4 54.3 215 13 6 9.4 5.2
10500 10.2 50.4 225 6 3 8.3 4.5 | 13.1 55.6 210 12 6 10.1 5.5
10250 10.8 51.4 220 5 3 9.5 5.2 | 13.9 57.0 210 12 6 11.4 6.2
10000 11.4 52.5 220 4 2 9.9 5.5 | 14.8 58.6 210 12 6 12.2 6.7
9750 12.1 53.8 215 3 2 7.7 4.2 | 15.6 60.1 210 12 6 8.9 4.9
9500 12.6 54.7 205 2 1 11.2 6.2 | 16.3 61.3 210 11 6 14.2 7.8
9250 13.9 57.0 210 2 1 24.1 13.2 | 18.1 64.6 205 10 5 33.8 18.6
9000 15.3 59.5 210 2 1 0.1 0.1 | M M M M M M M
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
08/10/2025 at 1500 MDT | 08/10/2025 at 1800 MDT
|
CAPE... +506.6 LI... -1.7 | CAPE... +120.0 LI... +0.1
CINH... -32.9 K Index... +27.1 | CINH... -147.1 K Index... +14.2
|
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 -59.3 -74.7 310 11 5 1.2 0.7 | -58.6 -73.5 325 12 6 0.9 0.5
45000 -57.7 -71.9 305 16 8 0.7 0.4 | -57.6 -71.7 295 12 6 -0.1 -0.0
40000 -56.1 -69.0 290 21 11 6.7 3.7 | -56.7 -70.1 265 15 8 7.5 4.1
38000 -52.4 -62.3 290 24 12 6.1 3.4 | -52.2 -62.0 255 17 9 7.5 4.1
36000 -48.7 -55.7 290 28 14 6.2 3.4 | -47.7 -53.9 245 19 10 7.4 4.1
34000 -43.3 -45.9 285 28 14 8.6 4.7 | -42.4 -44.3 250 19 10 9.0 4.9
32000 -38.1 -36.6 275 28 14 8.6 4.7 | -37.1 -34.8 260 20 10 8.8 4.9
30000 -33.1 -27.6 265 28 14 8.1 4.5 | -32.3 -26.1 255 25 13 7.7 4.2
29000 -30.7 -23.3 260 28 14 8.2 4.5 | -30.0 -22.0 255 27 14 7.7 4.2
28000 -28.3 -18.9 260 28 15 7.5 4.1 | -27.7 -17.9 255 30 16 7.5 4.1
27000 -26.1 -15.0 260 31 16 7.2 3.9 | -25.3 -13.5 250 32 16 6.4 3.5
26000 -24.0 -11.2 260 33 17 7.2 3.9 | -23.3 -9.9 250 33 17 6.5 3.5
25000 -21.9 -7.4 260 36 18 7.2 3.9 | -21.4 -6.5 250 34 18 6.3 3.4
24000 -19.9 -3.8 265 37 19 6.8 3.7 | -19.8 -3.6 260 33 17 5.4 2.9
23000 -17.9 -0.2 270 39 20 6.8 3.7 | -18.2 -0.8 265 32 16 5.4 3.0
22000 -15.9 3.4 275 41 21 7.2 4.0 | -16.6 2.1 275 32 16 6.9 3.8
21000 -13.5 7.7 275 35 18 8.3 4.5 | -13.9 7.0 280 32 17 9.4 5.1
20000 -11.1 12.0 285 30 15 8.3 4.6 | -11.1 12.0 280 33 17 9.4 5.1
19500 -9.9 14.2 285 27 14 8.3 4.6 | -9.7 14.5 280 33 17 9.5 5.2
19000 -8.7 16.3 290 25 13 8.3 4.5 | -8.4 16.9 285 32 17 7.9 4.3
18500 -7.5 18.5 290 24 12 8.3 4.6 | -7.2 19.0 285 32 16 8.1 4.5
18000 -6.3 20.7 290 23 12 8.8 4.8 | -6.1 21.0 285 31 16 8.4 4.6
17500 -4.9 23.2 290 22 12 9.4 5.2 | -4.8 23.4 290 29 15 8.5 4.7
17000 -3.5 25.7 285 22 11 9.5 5.2 | -3.6 25.5 290 27 14 8.5 4.7
16500 -2.1 28.2 285 21 11 9.4 5.2 | -2.2 28.0 290 25 13 9.6 5.3
16000 0.0 32.0 280 18 10 9.4 5.2 | -0.8 30.6 290 24 12 9.5 5.2
15500 1.4 34.5 280 17 9 8.7 4.7 | 0.6 33.1 290 23 12 9.5 5.2
15000 2.6 36.7 275 16 8 9.0 4.9 | 2.0 35.6 290 22 12 9.5 5.2
14500 3.8 38.8 265 15 8 7.7 4.2 | 3.4 38.1 290 22 11 8.4 4.6
14000 5.1 41.2 260 14 7 8.7 4.8 | 5.4 41.7 290 21 11 9.6 5.2
13500 6.3 43.3 255 13 7 7.2 3.9 | 6.8 44.2 290 21 11 8.0 4.4
13000 7.5 45.5 245 12 6 8.7 4.8 | 8.0 46.4 285 19 10 9.1 5.0
12500 8.7 47.7 235 12 6 8.3 4.5 | 9.3 48.7 280 18 9 7.9 4.3
12000 9.9 49.8 225 12 6 8.4 4.6 | 10.3 50.5 275 16 8 7.2 3.9
11750 10.5 50.9 220 12 6 8.8 4.8 | 10.9 51.6 270 16 8 8.2 4.5
11500 11.1 52.0 215 12 6 8.5 4.7 | 11.4 52.5 265 15 8 6.1 3.3
11250 11.8 53.2 215 12 6 8.3 4.5 | 11.7 53.1 260 15 8 3.5 1.9
11000 12.4 54.3 210 12 6 8.1 4.4 | 12.0 53.6 255 14 7 3.4 1.9
10750 13.0 55.4 205 12 6 9.5 5.2 | 12.2 54.0 250 14 7 4.3 2.4
10500 13.7 56.7 205 12 6 10.4 5.7 | 12.5 54.5 245 14 7 3.9 2.2
10250 14.5 58.1 205 12 6 9.6 5.3 | 12.7 54.9 240 13 7 2.3 1.3
10000 15.2 59.4 200 12 6 9.9 5.4 | 12.8 55.0 230 12 6 2.6 1.4
9750 15.9 60.6 200 12 6 9.1 5.0 | 12.9 55.2 225 11 6 1.7 0.9
9500 16.7 62.1 200 12 6 13.5 7.4 | 13.0 55.4 215 11 6 6.5 3.6
9250 18.0 64.4 195 10 5 23.6 13.0 | 13.9 57.0 210 9 5 17.7 9.7
9000 19.6 67.3 195 9 5 9.9 5.4 | 14.9 58.8 200 7 4 1.7 0.9
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