Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
619
UXUS97 KPUB 191217
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0616 MDT Saturday, July 19, 2025
This forecast is for Villa Grove, CO for Saturday, July 19, 2025:
If the trigger temperature of 68.3 F/20.2 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 1201 ft/min (6.1 m/s)
Maximum height of thermals.................. 21680 ft MSL (12684 ft AGL)
Forecast maximum temperature................... 83.0 F/28.8 C
Time of trigger temperature.................... 0930 MDT
Time of overdevelopment........................ 1400 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 18794 ft MSL (9798 ft AGL)
Thermal soaring outlook for Sunday 07/20....... Excellent
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 05:55:52 / 20:24:02 MDT
Total possible sunshine........... 14 hr 28 min 11 sec (868 min 11 sec)
Altitude of sun at 13:09:57 MDT... 72.29 degrees
Upper air data from numerical model forecast valid on 07/19/2025 at 0600 MDT
Freezing level.................. 16542 ft MSL (7546 ft AGL)
Convective condensation level... 16023 ft MSL (7027 ft AGL)
Lifted condensation level....... 18608 ft MSL (9611 ft AGL)
Lifted index.................... -5.0
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 -66.9 -88.4 245 27 14 1.6 0.9 M M M M M
45000 -61.3 -78.3 245 44 23 7.2 3.9 M M M M M
40000 -50.4 -58.7 250 45 23 7.4 4.1 M M M M M
38000 -46.0 -50.8 245 43 22 7.4 4.1 M M M M M
36000 -41.5 -42.7 235 41 21 7.8 4.3 M M M M M
34000 -36.6 -33.9 235 37 19 8.3 4.5 M M M M M
32000 -31.0 -23.8 240 32 17 8.1 4.4 39.9 103.9 9.0 M M
30000 -26.8 -16.2 230 31 16 7.0 3.8 37.6 99.7 7.3 M M
29000 -24.8 -12.6 225 30 15 7.0 3.8 36.6 98.0 6.6 M M
28000 -22.7 -8.9 225 29 15 6.8 3.7 35.7 96.2 5.8 M M
27000 -20.7 -5.3 225 27 14 6.8 3.7 34.5 94.1 4.9 M M
26000 -18.6 -1.5 225 24 12 6.8 3.7 33.4 92.2 4.1 M M
25000 -16.6 2.1 225 22 11 6.6 3.6 32.5 90.5 3.3 M M
24000 -14.7 5.5 220 18 9 6.4 3.5 31.2 88.2 2.3 M M
23000 -12.8 9.0 215 15 8 6.4 3.5 30.0 86.0 1.3 M M
22000 -10.8 12.6 210 12 6 6.5 3.5 29.0 84.1 0.4 M M
21000 -8.9 16.0 210 12 6 6.5 3.6 27.8 82.0 -0.7 1146 5.8
20000 -7.0 19.4 205 13 6 6.6 3.6 26.7 80.0 -1.7 1060 5.4
19500 -6.0 21.2 205 13 7 6.6 3.6 26.2 79.2 -2.2 1016 5.2
19000 -5.1 22.8 205 13 7 6.7 3.7 25.7 78.3 -2.7 973 4.9
18500 -4.1 24.6 205 13 7 6.8 3.7 25.2 77.3 -3.2 929 4.7
18000 -3.2 26.2 210 13 7 6.9 3.8 24.7 76.5 -3.7 885 4.5
17500 -2.2 28.0 215 13 7 7.0 3.9 24.3 75.7 -4.2 840 4.3
17000 -0.7 30.7 220 13 7 7.0 3.8 23.6 74.5 -4.9 773 3.9
16500 0.3 32.5 230 13 7 6.9 3.8 23.1 73.6 -5.5 729 3.7
16000 1.3 34.3 240 13 7 6.9 3.8 22.7 72.8 -6.0 685 3.5
15500 2.2 36.0 245 14 7 6.7 3.7 22.2 72.0 -6.5 642 3.3
15000 3.1 37.6 250 14 7 6.5 3.6 21.7 71.1 -7.1 600 3.0
14500 4.2 39.6 255 15 8 9.2 5.1 21.5 70.6 -7.5 552 2.8
14000 5.5 41.9 255 16 8 8.7 4.8 21.3 70.3 -7.7 499 2.5
13500 6.9 44.4 255 17 9 11.5 6.3 21.3 70.3 -7.8 442 2.2
13000 8.4 47.1 255 17 9 7.7 4.2 21.3 70.3 -7.9 384 1.9
12500 9.6 49.3 255 17 9 8.4 4.6 21.0 69.9 -8.2 333 1.7
12000 10.8 51.4 250 18 9 7.0 3.9 20.9 69.6 -8.4 280 1.4
11750 11.2 52.2 250 18 9 4.9 2.7 20.6 69.0 -8.8 261 1.3
11500 11.6 52.9 250 19 10 5.0 2.7 20.2 68.4 -9.1 243 1.2
11250 11.9 53.4 245 19 10 4.4 2.4 19.8 67.7 -9.6 226 1.1
11000 12.2 54.0 245 19 10 4.4 2.4 19.4 66.9 -10.1 210 1.1
10750 12.5 54.5 245 19 10 4.8 2.7 19.0 66.2 -10.5 194 1.0
10500 12.7 54.9 240 19 10 1.6 0.9 18.6 65.4 -11.0 179 0.9
10250 12.6 54.7 240 18 9 -1.8 -1.0 17.7 63.9 -11.9 176 0.9
10000 12.4 54.3 240 17 9 -2.6 -1.4 16.9 62.3 -12.9 175 0.9
9750 12.2 54.0 240 16 8 0.9 0.5 16.0 60.8 -13.9 174 0.9
9500 12.1 53.8 235 16 8 -3.8 -2.1 15.3 59.6 -14.7 167 0.9
9250 11.2 52.2 235 11 6 -22.8 -12.5 13.6 56.5 -16.4 188 1.0
9000 10.1 50.2 235 7 3 7.9 4.3 11.7 53.0 -18.2 213 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 * * * * * *
07/19/2025 at 0900 MDT | 07/19/2025 at 1200 MDT
|
CAPE... +444.8 LI... -2.1 | CAPE... +116.4 LI... -1.0
CINH... -11.9 K Index... +14.6 | CINH... -0.9 K Index... +19.1
|
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 -66.9 -88.4 235 29 15 1.0 0.6 | -66.6 -87.9 230 27 14 0.4 0.2
45000 -61.6 -78.9 235 41 21 7.5 4.1 | -62.0 -79.6 230 41 21 7.3 4.0
40000 -50.2 -58.4 245 39 20 7.9 4.4 | -50.8 -59.4 235 42 21 8.2 4.5
38000 -45.4 -49.7 240 41 21 7.9 4.4 | -45.9 -50.6 235 43 22 8.2 4.5
36000 -40.7 -41.3 235 43 22 7.7 4.2 | -41.0 -41.8 235 44 23 8.0 4.4
34000 -36.2 -33.2 235 36 19 7.4 4.1 | -36.3 -33.3 230 42 21 7.8 4.3
32000 -31.2 -24.2 225 29 15 8.1 4.4 | -31.0 -23.8 225 40 20 7.8 4.3
30000 -26.8 -16.2 230 28 14 7.4 4.1 | -26.9 -16.4 220 35 18 7.0 3.8
29000 -24.5 -12.1 230 27 14 7.4 4.1 | -24.8 -12.6 220 33 17 7.0 3.9
28000 -22.5 -8.5 230 26 14 5.8 3.2 | -22.8 -9.0 215 31 16 6.3 3.4
27000 -20.7 -5.3 225 25 13 5.9 3.2 | -20.9 -5.6 220 29 15 6.3 3.5
26000 -19.0 -2.2 220 23 12 6.0 3.3 | -19.1 -2.4 220 27 14 6.3 3.5
25000 -17.3 0.9 215 21 11 6.6 3.6 | -17.2 1.0 220 25 13 6.3 3.5
24000 -15.1 4.8 215 19 10 7.1 3.9 | -15.2 4.6 220 23 12 6.3 3.4
23000 -12.8 9.0 215 17 9 7.2 3.9 | -13.3 8.1 220 21 11 6.3 3.5
22000 -10.7 12.7 215 14 7 6.5 3.6 | -11.4 11.5 220 19 10 6.3 3.4
21000 -8.9 16.0 210 15 8 6.2 3.4 | -9.6 14.7 225 17 9 6.3 3.5
20000 -7.0 19.4 205 16 8 6.3 3.4 | -7.7 18.1 225 16 8 6.4 3.5
19500 -6.1 21.0 205 16 8 6.3 3.5 | -6.8 19.8 230 15 8 6.5 3.6
19000 -5.2 22.6 205 16 8 6.9 3.8 | -5.9 21.4 230 14 7 7.1 3.9
18500 -4.1 24.6 205 15 8 6.9 3.8 | -4.9 23.2 230 12 6 7.1 3.9
18000 -3.1 26.4 210 14 7 7.4 4.1 | -3.8 25.2 235 11 5 7.5 4.1
17500 -2.0 28.4 215 13 7 7.7 4.2 | -2.7 27.1 245 11 6 7.6 4.2
17000 -0.9 30.4 225 12 6 7.6 4.2 | -1.6 29.1 255 12 6 7.6 4.2
16500 0.2 32.4 230 11 6 7.0 3.8 | -0.5 31.1 265 13 7 7.7 4.2
16000 1.1 34.0 240 12 6 7.2 3.9 | 1.1 34.0 275 16 8 8.2 4.5
15500 2.1 35.8 250 12 6 6.4 3.5 | 2.4 36.3 280 16 8 9.2 5.1
15000 3.3 37.9 255 13 7 6.3 3.5 | 3.7 38.7 280 16 8 9.2 5.0
14500 4.3 39.7 260 15 8 7.9 4.3 | 5.1 41.2 280 16 8 9.9 5.4
14000 5.4 41.7 265 16 8 7.8 4.3 | 6.5 43.7 280 16 8 9.6 5.2
13500 6.6 43.9 270 17 9 9.7 5.3 | 8.1 46.6 285 15 8 11.5 6.3
13000 7.9 46.2 275 18 9 8.0 4.4 | 9.6 49.3 285 15 8 8.8 4.8
12500 9.2 48.6 280 19 10 8.5 4.7 | 11.0 51.8 285 15 8 10.1 5.5
12000 10.4 50.7 280 19 10 8.6 4.7 | 12.5 54.5 285 15 8 9.9 5.4
11750 11.1 52.0 280 18 9 8.4 4.6 | 13.2 55.8 285 15 8 9.5 5.2
11500 11.7 53.1 285 18 9 8.4 4.6 | 14.0 57.2 285 15 7 9.6 5.2
11250 12.3 54.1 285 18 9 8.4 4.6 | 14.7 58.5 285 14 7 9.5 5.2
11000 12.9 55.2 285 17 9 8.2 4.5 | 15.4 59.7 285 14 7 9.5 5.2
10750 13.5 56.3 285 17 9 9.6 5.3 | 16.1 61.0 285 14 7 10.6 5.8
10500 14.2 57.6 285 16 8 9.2 5.1 | 17.0 62.6 285 14 7 11.4 6.3
10250 14.8 58.6 285 15 8 7.7 4.2 | 17.8 64.0 285 14 7 11.0 6.0
10000 15.3 59.5 280 13 7 8.4 4.6 | 18.6 65.5 285 13 7 11.8 6.5
9750 15.8 60.4 280 12 6 7.5 4.1 | 19.5 67.1 285 13 7 8.9 4.9
9500 16.5 61.7 275 10 5 12.5 6.8 | 20.2 68.4 285 13 6 16.2 8.9
9250 17.7 63.9 275 9 5 22.8 12.5 | 22.2 72.0 285 12 6 37.0 20.3
9000 19.0 66.2 270 7 4 3.9 2.1 | 24.2 75.6 285 11 6 -0.8 -0.4
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
07/19/2025 at 1500 MDT | 07/19/2025 at 1800 MDT
|
CAPE... +55.3 LI... -0.9 | CAPE... +13.0 LI... -0.5
CINH... -0.2 K Index... +24.0 | CINH... -12.8 K Index... +23.2
|
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 -65.7 -86.3 225 30 15 0.9 0.5 | -66.3 -87.3 220 26 13 1.5 0.8
45000 -61.2 -78.2 225 43 22 6.7 3.7 | -61.3 -78.3 220 39 20 6.6 3.6
40000 -50.4 -58.7 230 45 23 7.9 4.3 | -50.4 -58.7 225 43 22 8.4 4.6
38000 -45.6 -50.1 230 45 23 7.9 4.3 | -45.3 -49.5 230 44 22 8.4 4.6
36000 -40.9 -41.6 230 46 23 7.9 4.3 | -40.3 -40.5 230 44 23 8.0 4.4
34000 -36.2 -33.2 225 44 23 7.9 4.3 | -35.6 -32.1 230 43 22 7.9 4.3
32000 -31.5 -24.7 225 42 22 8.2 4.5 | -30.9 -23.6 230 42 22 7.9 4.3
30000 -27.5 -17.5 220 40 21 6.8 3.7 | -27.1 -16.8 225 42 22 6.3 3.5
29000 -25.5 -13.9 215 39 20 6.8 3.7 | -25.2 -13.4 225 42 22 6.3 3.5
28000 -23.5 -10.3 215 38 20 6.9 3.8 | -23.4 -10.1 225 42 21 6.4 3.5
27000 -21.0 -5.8 220 35 18 6.9 3.8 | -21.5 -6.7 225 39 20 6.4 3.5
26000 -18.9 -2.0 225 33 17 6.9 3.8 | -19.2 -2.6 225 35 18 6.5 3.6
25000 -16.9 1.6 225 30 15 6.2 3.4 | -17.2 1.0 230 32 16 7.4 4.0
24000 -15.1 4.8 225 26 13 6.0 3.3 | -15.1 4.8 235 24 13 7.5 4.1
23000 -13.3 8.1 230 22 11 6.0 3.3 | -12.9 8.8 240 18 9 7.6 4.1
22000 -11.5 11.3 230 18 9 6.1 3.4 | -10.8 12.6 255 12 6 5.6 3.1
21000 -9.7 14.5 240 15 8 6.2 3.4 | -9.2 15.4 270 10 5 5.4 2.9
20000 -8.0 17.6 245 13 7 6.2 3.4 | -7.6 18.3 285 9 5 5.4 3.0
19500 -7.1 19.2 255 12 6 6.7 3.7 | -6.8 19.8 295 9 5 6.2 3.4
19000 -6.0 21.2 260 10 5 7.9 4.4 | -5.7 21.7 305 9 4 7.9 4.3
18500 -4.8 23.4 275 9 5 7.9 4.3 | -4.5 23.9 315 8 4 7.8 4.3
18000 -3.7 25.3 290 9 4 9.1 5.0 | -3.3 26.1 320 8 4 9.2 5.0
17500 -2.3 27.9 290 9 4 9.3 5.1 | -1.9 28.6 320 9 4 9.4 5.1
17000 -0.9 30.4 295 9 5 9.4 5.2 | -0.6 30.9 320 9 4 9.5 5.2
16500 0.5 32.9 295 9 5 9.9 5.4 | 0.8 33.4 320 8 4 9.7 5.3
16000 2.0 35.6 295 9 5 9.9 5.4 | 2.2 36.0 320 8 4 9.7 5.3
15500 3.4 38.1 300 9 5 9.6 5.3 | 3.6 38.5 320 8 4 9.1 5.0
15000 4.8 40.6 300 9 5 9.6 5.3 | 5.0 41.0 315 8 4 9.3 5.1
14500 6.3 43.3 300 9 5 9.9 5.4 | 6.3 43.3 315 8 4 8.1 4.5
14000 8.5 47.3 300 9 5 9.7 5.3 | 7.6 45.7 305 8 4 9.3 5.1
13500 10.0 50.0 300 9 5 10.4 5.7 | 9.0 48.2 300 8 4 8.9 4.9
13000 11.4 52.5 300 9 5 9.5 5.2 | 11.0 51.8 290 8 4 9.6 5.2
12500 12.9 55.2 300 9 5 9.6 5.3 | 12.3 54.1 280 8 4 8.2 4.5
12000 14.3 57.7 300 9 4 10.0 5.5 | 13.5 56.3 270 8 4 9.1 5.0
11750 15.1 59.2 300 9 4 10.4 5.7 | 14.3 57.7 265 8 4 10.1 5.5
11500 15.8 60.4 300 9 4 9.7 5.3 | 15.0 59.0 265 8 4 8.7 4.8
11250 16.5 61.7 300 9 4 9.0 5.0 | 15.6 60.1 260 8 4 7.9 4.3
11000 17.2 63.0 300 8 4 9.3 5.1 | 16.2 61.2 255 9 4 8.1 4.4
10750 18.0 64.4 300 8 4 11.0 6.1 | 16.8 62.2 250 9 5 9.2 5.1
10500 18.8 65.8 305 8 4 11.4 6.3 | 17.5 63.5 245 9 5 9.2 5.0
10250 19.6 67.3 305 8 4 10.2 5.6 | 18.1 64.6 240 9 5 8.4 4.6
10000 20.4 68.7 305 8 4 10.8 5.9 | 18.7 65.7 235 9 5 8.3 4.6
9750 21.2 70.2 305 8 4 9.4 5.1 | 19.3 66.7 230 9 5 9.3 5.1
9500 21.9 71.4 305 8 4 14.9 8.1 | 20.1 68.2 225 9 5 9.5 5.2
9250 23.5 74.3 300 7 4 28.5 15.6 | 20.6 69.1 225 8 4 6.8 3.7
9000 25.3 77.5 300 7 4 7.5 4.1 | 21.2 70.2 220 6 3 12.4 6.8
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