Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
114
UXUS97 KPUB 221211
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0611 MDT Saturday, June 22, 2024
This forecast is for Villa Grove, CO for Saturday, June 22, 2024:
If the trigger temperature of 67.1 F/19.5 C is reached...then
Thermal Soaring Index....................... Fair
Maximum rate of lift........................ 566 ft/min (2.9 m/s)
Maximum height of thermals.................. 19085 ft MSL (10112 ft AGL)
Forecast maximum temperature................... 77.0 F/25.5 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ 1700 MDT
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 16596 ft MSL (7623 ft AGL)
Thermal soaring outlook for Sunday 06/23....... Good
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 05:40:54 / 20:30:40 MDT
Total possible sunshine........... 14 hr 49 min 46 sec (889 min 46 sec)
Altitude of sun at 13:05:47 MDT... 75.11 degrees
Upper air data from numerical model forecast valid on 06/22/2024 at 0600 MDT
Freezing level.................. 16105 ft MSL (7132 ft AGL)
Convective condensation level... 17520 ft MSL (8547 ft AGL)
Lifted condensation level....... 18535 ft MSL (9562 ft AGL)
Lifted index.................... -1.5
K index......................... +9.0
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 -62.1 -79.8 240 41 21 4.1 2.3 M M M M M
45000 -56.0 -68.8 245 60 31 3.6 2.0 M M M M M
40000 -49.5 -57.1 250 79 41 7.7 4.2 M M M M M
38000 -44.8 -48.6 245 75 38 7.7 4.2 M M M M M
36000 -40.2 -40.4 240 70 36 7.6 4.2 M M M M M
34000 -35.8 -32.4 240 61 31 7.4 4.0 M M M M M
32000 -31.3 -24.3 235 52 27 7.3 4.0 M M M M M
30000 -27.3 -17.1 240 48 24 5.7 3.1 37.1 98.7 9.5 M M
29000 -25.6 -14.1 245 46 24 5.7 3.1 35.6 96.1 8.4 M M
28000 -23.7 -10.7 245 44 23 8.2 4.5 34.5 94.1 7.6 M M
27000 -21.2 -6.2 245 42 21 8.1 4.5 33.8 92.8 7.2 M M
26000 -18.7 -1.7 245 39 20 8.2 4.5 33.2 91.7 6.8 M M
25000 -16.3 2.7 250 36 18 7.9 4.3 32.7 90.9 6.5 M M
24000 -14.0 6.8 250 34 17 7.7 4.2 31.9 89.4 5.9 M M
23000 -11.7 10.9 255 31 16 7.8 4.3 31.2 88.2 5.3 M M
22000 -9.4 15.1 255 29 15 5.9 3.2 30.6 87.1 4.8 M M
21000 -8.1 17.4 265 30 15 4.5 2.5 28.7 83.6 3.1 M M
20000 -6.9 19.6 270 30 16 4.7 2.6 27.0 80.5 1.5 M M
19500 -6.2 20.8 270 31 16 4.8 2.6 26.2 79.1 0.7 M M
19000 -5.5 22.1 275 31 16 5.0 2.8 25.4 77.6 -0.0 964 4.9
18500 -4.8 23.4 280 31 16 5.1 2.8 24.6 76.2 -0.8 927 4.7
18000 -4.0 24.8 280 30 16 5.7 3.1 23.8 74.9 -1.5 890 4.5
17500 -3.1 26.4 285 29 15 6.2 3.4 23.2 73.8 -2.0 847 4.3
17000 -2.2 28.0 290 28 14 6.2 3.4 22.6 72.8 -2.6 805 4.1
16500 -1.1 30.0 290 27 14 7.6 4.2 22.2 71.9 -3.0 759 3.9
16000 -0.0 32.0 295 26 13 7.5 4.1 21.8 71.3 -3.4 710 3.6
15500 1.1 34.0 300 25 13 7.9 4.3 21.5 70.7 -3.7 662 3.4
15000 2.9 37.2 300 24 12 8.1 4.4 21.0 69.9 -4.2 587 3.0
14500 4.0 39.2 300 24 12 7.8 4.3 20.8 69.4 -4.5 537 2.7
14000 5.2 41.4 300 23 12 8.1 4.4 20.5 68.9 -4.8 487 2.5
13500 6.5 43.7 300 23 12 9.5 5.2 20.3 68.5 -5.0 435 2.2
13000 7.7 45.9 300 22 11 7.2 3.9 20.1 68.2 -5.3 383 1.9
12500 8.8 47.8 295 21 11 7.5 4.1 19.7 67.5 -5.7 336 1.7
12000 9.8 49.6 295 20 10 7.0 3.8 19.4 67.0 -6.2 290 1.5
11750 10.2 50.4 290 20 10 6.2 3.4 19.2 66.5 -6.5 271 1.4
11500 10.6 51.1 290 20 10 5.7 3.1 18.9 66.0 -6.9 251 1.3
11250 10.9 51.6 285 19 10 5.1 2.8 18.5 65.3 -7.3 235 1.2
11000 11.2 52.2 280 19 10 4.9 2.7 18.2 64.7 -7.8 219 1.1
10750 11.5 52.7 275 18 9 6.8 3.8 17.8 64.1 -8.2 203 1.0
10500 11.8 53.2 275 18 9 1.9 1.0 17.6 63.6 -8.6 185 0.9
10250 11.6 52.9 270 17 9 -4.6 -2.5 16.6 61.9 -9.7 186 0.9
10000 11.2 52.2 265 16 8 -3.3 -1.8 15.6 60.0 -10.8 190 1.0
9750 10.8 51.4 260 15 8 -5.0 -2.7 14.6 58.2 -11.9 194 1.0
9500 10.3 50.5 250 14 7 -3.1 -1.7 13.4 56.2 -13.2 201 1.0
9250 10.3 50.5 245 10 5 4.2 2.3 12.8 55.0 -13.9 194 1.0
9000 10.3 50.5 240 7 4 -9.7 -5.3 12.1 53.7 -14.7 185 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 * * * * * *
06/22/2024 at 0900 MDT | 06/22/2024 at 1200 MDT
|
CAPE... +507.1 LI... -1.7 | CAPE... +435.1 LI... -2.4
CINH... -54.9 K Index... +4.1 | CINH... -0.6 K Index... +3.9
|
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 -63.3 -81.9 245 48 25 3.3 1.8 | -63.8 -82.8 240 55 28 3.4 1.9
45000 -57.0 -70.6 250 69 36 5.2 2.9 | -57.2 -71.0 250 77 39 5.5 3.0
40000 -48.5 -55.3 250 81 41 7.2 4.0 | -48.3 -54.9 250 83 43 7.9 4.3
38000 -44.2 -47.6 250 77 40 7.2 4.0 | -43.5 -46.3 250 81 42 7.9 4.3
36000 -39.9 -39.8 245 74 38 6.9 3.8 | -38.8 -37.8 245 81 42 6.6 3.6
34000 -36.0 -32.8 245 65 33 6.5 3.5 | -35.7 -32.3 240 67 35 5.1 2.8
32000 -32.1 -25.8 235 56 29 6.3 3.5 | -32.6 -26.7 240 54 28 5.0 2.7
30000 -27.7 -17.9 245 50 26 6.6 3.6 | -27.6 -17.7 240 52 27 7.8 4.3
29000 -25.7 -14.3 245 49 25 6.6 3.6 | -25.3 -13.5 240 51 26 7.8 4.3
28000 -23.6 -10.5 250 46 24 7.1 3.9 | -23.1 -9.6 240 50 26 5.8 3.2
27000 -21.5 -6.7 250 42 22 7.0 3.9 | -21.3 -6.3 245 46 24 6.0 3.3
26000 -19.4 -2.9 250 38 19 7.0 3.9 | -19.5 -3.1 250 42 22 6.0 3.3
25000 -17.3 0.9 255 34 17 7.5 4.1 | -17.6 0.3 255 39 20 6.8 3.7
24000 -15.0 5.0 255 32 17 7.8 4.3 | -15.5 4.1 255 35 18 7.3 4.0
23000 -12.6 9.3 255 31 16 7.8 4.3 | -13.3 8.1 260 32 17 7.3 4.0
22000 -10.3 13.5 255 29 15 6.0 3.3 | -11.1 12.0 260 29 15 5.8 3.2
21000 -8.9 16.0 265 28 14 5.0 2.7 | -9.6 14.7 265 26 13 5.0 2.8
20000 -7.4 18.7 270 27 14 5.1 2.8 | -8.1 17.4 270 22 12 5.0 2.8
19500 -6.7 19.9 275 27 14 5.0 2.8 | -7.4 18.7 275 21 11 5.1 2.8
19000 -6.0 21.2 280 27 14 4.4 2.4 | -6.6 20.1 280 20 10 5.7 3.1
18500 -5.4 22.3 285 26 13 4.5 2.5 | -5.8 21.6 290 20 10 5.7 3.1
18000 -4.7 23.5 290 26 13 6.2 3.4 | -5.0 23.0 295 20 10 6.7 3.7
17500 -3.7 25.3 290 24 12 7.2 3.9 | -4.0 24.8 295 20 10 7.1 3.9
17000 -2.7 27.1 295 22 11 7.3 4.0 | -3.0 26.6 300 19 10 7.4 4.1
16500 -1.5 29.3 295 21 11 7.9 4.3 | -1.9 28.6 300 18 9 8.4 4.6
16000 -0.4 31.3 300 19 10 7.8 4.3 | -0.7 30.7 300 16 8 8.3 4.6
15500 0.8 33.4 305 18 9 8.5 4.7 | 0.5 32.9 300 15 8 9.5 5.2
15000 2.1 35.8 305 17 9 8.6 4.7 | 1.9 35.4 300 14 7 9.6 5.3
14500 4.0 39.2 305 16 8 8.3 4.6 | 3.9 39.0 295 12 6 8.9 4.9
14000 5.3 41.5 310 16 8 8.8 4.9 | 5.3 41.5 295 11 6 9.8 5.4
13500 6.7 44.1 310 15 8 9.5 5.2 | 6.8 44.2 290 10 5 10.4 5.7
13000 8.0 46.4 305 15 8 7.8 4.3 | 8.1 46.6 290 10 5 8.9 4.9
12500 9.2 48.6 305 15 8 8.0 4.4 | 9.5 49.1 285 9 5 9.9 5.4
12000 10.3 50.5 300 14 7 7.2 3.9 | 10.9 51.6 285 9 5 9.5 5.2
11750 10.8 51.4 300 14 7 6.0 3.3 | 11.6 52.9 285 9 4 8.9 4.9
11500 11.2 52.2 295 14 7 5.7 3.1 | 12.3 54.1 280 8 4 9.2 5.0
11250 11.5 52.7 290 14 7 5.3 2.9 | 12.9 55.2 280 8 4 9.2 5.1
11000 11.8 53.2 285 14 7 5.3 2.9 | 13.6 56.5 280 8 4 9.1 5.0
10750 12.1 53.8 280 15 7 6.9 3.8 | 14.3 57.7 280 8 4 10.9 6.0
10500 12.4 54.3 280 15 7 4.1 2.2 | 15.2 59.4 280 8 4 11.3 6.2
10250 12.4 54.3 275 13 7 0.6 0.3 | 15.9 60.6 275 8 4 10.2 5.6
10000 12.4 54.3 265 12 6 1.8 1.0 | 16.7 62.1 275 7 4 10.5 5.8
9750 12.4 54.3 260 11 6 1.6 0.9 | 17.4 63.3 275 7 4 10.2 5.6
9500 12.5 54.5 250 10 5 9.7 5.3 | 18.3 64.9 275 7 4 17.4 9.6
9250 13.7 56.7 245 9 4 23.0 12.6 | 20.1 68.2 270 7 3 29.7 16.3
9000 14.9 58.8 235 8 4 -0.3 -0.1 | 21.8 71.2 270 6 3 8.0 4.4
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
06/22/2024 at 1500 MDT | 06/22/2024 at 1800 MDT
|
CAPE... +197.3 LI... -2.6 | CAPE... +514.5 LI... -3.6
CINH... -0.0 K Index... +25.7 | CINH... -12.6 K Index... +26.5
|
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 -64.1 -83.4 245 52 27 2.6 1.4 | -63.5 -82.3 250 51 26 2.6 1.4
45000 -57.8 -72.0 250 73 38 6.2 3.4 | -57.6 -71.7 255 70 36 5.6 3.1
40000 -48.1 -54.6 255 83 42 7.6 4.1 | -48.5 -55.3 255 78 40 8.0 4.4
38000 -43.5 -46.3 250 82 42 7.6 4.1 | -43.7 -46.7 250 74 38 8.0 4.4
36000 -39.0 -38.2 240 82 42 6.9 3.8 | -39.0 -38.2 245 72 37 7.2 4.0
34000 -35.3 -31.5 250 72 37 6.2 3.4 | -35.1 -31.2 250 65 34 6.5 3.6
32000 -31.1 -24.0 255 63 33 6.7 3.7 | -30.7 -23.3 260 59 31 6.8 3.7
30000 -27.3 -17.1 250 56 29 6.4 3.5 | -27.2 -17.0 260 51 26 5.7 3.2
29000 -25.3 -13.5 250 52 27 6.4 3.5 | -25.4 -13.7 260 47 24 5.8 3.2
28000 -23.4 -10.1 250 49 25 6.7 3.7 | -23.6 -10.5 260 44 23 6.7 3.7
27000 -21.4 -6.5 250 47 24 6.7 3.7 | -21.7 -7.1 260 43 22 6.6 3.6
26000 -19.4 -2.9 255 45 23 6.7 3.7 | -19.7 -3.5 265 42 22 6.6 3.6
25000 -17.4 0.7 255 43 22 6.5 3.6 | -17.7 0.1 265 41 21 6.5 3.6
24000 -15.5 4.1 260 40 21 6.4 3.5 | -15.8 3.6 270 38 19 6.4 3.5
23000 -13.6 7.5 260 37 19 6.4 3.5 | -13.9 7.0 270 34 18 6.5 3.5
22000 -11.7 10.9 265 34 17 5.3 2.9 | -12.0 10.4 275 31 16 6.1 3.4
21000 -10.4 13.3 270 26 14 4.9 2.7 | -10.2 13.6 275 24 12 6.1 3.4
20000 -9.0 15.8 270 19 10 5.2 2.9 | -8.5 16.7 270 17 9 6.5 3.5
19500 -8.3 17.1 275 16 8 6.0 3.3 | -7.7 18.1 270 13 7 7.1 3.9
19000 -7.2 19.0 275 13 7 9.4 5.2 | -6.5 20.3 270 11 6 9.4 5.2
18500 -5.9 21.4 270 12 6 9.3 5.1 | -5.2 22.6 265 9 5 9.4 5.1
18000 -4.6 23.7 270 10 5 8.7 4.8 | -3.9 25.0 265 7 4 8.5 4.7
17500 -3.4 25.9 270 9 4 8.5 4.7 | -2.7 27.1 265 7 3 8.3 4.5
17000 -2.2 28.0 270 7 4 8.7 4.7 | -1.5 29.3 260 6 3 8.4 4.6
16500 -0.8 30.6 270 7 3 9.3 5.1 | -0.2 31.6 260 6 3 9.0 5.0
16000 0.6 33.1 270 6 3 9.2 5.1 | 1.1 34.0 260 5 3 9.0 4.9
15500 2.7 36.9 270 6 3 9.8 5.4 | 2.5 36.5 255 5 3 9.5 5.2
15000 4.2 39.6 270 6 3 9.9 5.4 | 4.6 40.3 250 4 2 9.6 5.3
14500 5.7 42.3 265 5 3 9.7 5.3 | 5.8 42.4 240 4 2 8.0 4.4
14000 7.1 44.8 265 5 3 9.2 5.0 | 7.2 45.0 230 4 2 8.9 4.9
13500 8.6 47.5 265 5 3 11.8 6.5 | 8.6 47.5 220 4 2 10.4 5.7
13000 10.1 50.2 260 5 3 8.4 4.6 | 9.9 49.8 210 4 2 8.0 4.4
12500 11.4 52.5 260 5 3 9.8 5.4 | 11.1 52.0 200 5 3 8.7 4.8
12000 12.9 55.2 260 5 2 10.1 5.5 | 12.4 54.3 195 6 3 8.6 4.7
11750 13.7 56.7 260 5 2 10.1 5.5 | 13.1 55.6 190 6 3 8.4 4.6
11500 14.4 57.9 260 5 2 9.6 5.3 | 13.7 56.7 190 6 3 8.8 4.8
11250 15.1 59.2 255 4 2 9.2 5.1 | 14.3 57.7 190 6 3 9.1 5.0
11000 15.8 60.4 255 4 2 9.3 5.1 | 15.0 59.0 185 6 3 8.9 4.9
10750 16.5 61.7 255 4 2 10.2 5.6 | 15.7 60.3 185 6 3 11.2 6.1
10500 17.3 63.1 255 4 2 10.7 5.9 | 16.6 61.9 185 7 3 11.1 6.1
10250 18.1 64.6 255 4 2 10.2 5.6 | 17.3 63.1 180 7 3 9.2 5.0
10000 18.9 66.0 255 4 2 10.8 5.9 | 18.0 64.4 180 7 3 9.8 5.4
9750 19.6 67.3 255 4 2 8.9 4.9 | 18.7 65.7 180 7 3 9.4 5.2
9500 20.3 68.5 255 3 2 13.6 7.4 | 19.4 66.9 180 7 3 11.5 6.3
9250 21.8 71.2 250 4 2 26.9 14.7 | 20.4 68.7 175 6 3 15.4 8.5
9000 23.3 73.9 250 4 2 2.1 1.1 | 21.3 70.3 170 5 3 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
________________________________________________________________________________
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