Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
864
UXUS97 KPUB 011205
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0605 MDT Monday, July 1, 2024
This forecast is for Villa Grove, CO for Monday, July 1, 2024:
If the trigger temperature of 64.4 F/18.0 C is reached...then
Thermal Soaring Index....................... Good
Maximum rate of lift........................ 478 ft/min (2.4 m/s)
Maximum height of thermals.................. 16411 ft MSL (7440 ft AGL)
Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 13785 ft MSL (4814 ft AGL)
Thermal soaring outlook for Tuesday 07/02...... Good
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 05:44:20 / 20:30:54 MDT
Total possible sunshine........... 14 hr 46 min 34 sec (886 min 34 sec)
Altitude of sun at 13:07:37 MDT... 74.68 degrees
Upper air data from numerical model forecast valid on 07/01/2024 at 0600 MDT
Freezing level.................. 16327 ft MSL (7356 ft AGL)
Convective condensation level... 12705 ft MSL (3734 ft AGL)
Lifted condensation level....... 14619 ft MSL (5648 ft AGL)
Lifted index.................... -2.4
K index......................... +27.3
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 -64.6 -84.3 245 31 16 2.2 1.2 M M M M M
45000 -58.6 -73.5 235 42 22 6.2 3.4 M M M M M
40000 -48.9 -56.0 225 46 24 7.5 4.1 M M M M M
38000 -44.3 -47.7 230 41 21 7.5 4.1 M M M M M
36000 -39.8 -39.6 230 36 18 8.1 4.5 M M M M M
34000 -34.8 -30.6 235 37 19 8.4 4.6 M M M M M
32000 -29.7 -21.5 235 39 20 9.4 5.1 M M M M M
30000 -24.5 -12.1 230 40 21 7.8 4.3 40.4 104.7 14.3 M M
29000 -22.2 -8.0 230 41 21 7.8 4.3 39.7 103.5 13.9 M M
28000 -20.0 -4.0 230 41 21 6.6 3.6 38.9 102.0 13.3 M M
27000 -18.0 -0.4 225 40 21 6.7 3.7 37.7 99.9 12.4 M M
26000 -16.1 3.0 225 40 21 6.7 3.7 36.6 97.9 11.6 M M
25000 -14.1 6.6 220 40 20 6.1 3.4 35.7 96.2 10.9 M M
24000 -12.5 9.5 220 39 20 5.7 3.1 34.1 93.4 9.6 M M
23000 -10.8 12.6 215 39 20 5.7 3.1 32.7 90.8 8.5 M M
22000 -9.2 15.4 210 38 20 5.9 3.2 31.4 88.5 7.4 M M
21000 -7.4 18.7 210 38 20 6.1 3.3 30.0 86.0 6.2 M M
20000 -5.7 21.7 210 38 19 6.1 3.3 28.8 83.8 5.1 M M
19500 -4.8 23.4 205 38 19 6.2 3.4 28.2 82.8 4.6 M M
19000 -4.0 24.8 205 38 19 5.0 2.8 27.5 81.6 3.9 M M
18500 -3.3 26.1 205 38 20 5.1 2.8 26.8 80.2 3.2 M M
18000 -2.5 27.5 205 38 20 5.1 2.8 26.0 78.8 2.5 M M
17500 -1.8 28.8 205 38 19 5.0 2.7 25.2 77.4 1.8 M M
17000 -1.1 30.0 205 37 19 4.9 2.7 24.4 76.0 1.0 M M
16500 -0.4 31.3 205 36 18 5.2 2.9 23.7 74.6 0.3 M M
16000 0.3 32.5 205 34 17 5.2 2.8 22.9 73.3 -0.4 656 3.3
15500 1.1 34.0 205 31 16 6.9 3.8 22.3 72.1 -1.1 617 3.1
15000 2.7 36.9 205 26 13 7.8 4.3 21.7 71.1 -1.7 548 2.8
14500 3.6 38.5 205 23 12 5.9 3.2 21.3 70.3 -2.2 504 2.6
14000 4.5 40.1 210 21 11 6.1 3.4 20.7 69.3 -2.9 464 2.4
13500 5.4 41.7 215 19 10 6.6 3.6 20.2 68.3 -3.5 423 2.2
13000 6.1 43.0 220 17 9 4.5 2.5 19.5 67.1 -4.2 385 2.0
12500 6.8 44.2 225 16 8 5.1 2.8 18.7 65.7 -5.0 350 1.8
12000 7.6 45.7 235 14 7 5.0 2.7 18.1 64.6 -5.7 312 1.6
11750 7.9 46.2 240 14 7 4.4 2.4 17.7 63.8 -6.1 295 1.5
11500 8.2 46.8 245 13 7 3.3 1.8 17.3 63.1 -6.5 279 1.4
11250 8.4 47.1 250 13 7 1.9 1.0 16.7 62.0 -7.1 266 1.4
11000 8.5 47.3 260 14 7 2.0 1.1 16.1 61.0 -7.7 254 1.3
10750 8.7 47.7 265 14 7 2.2 1.2 15.5 59.9 -8.3 242 1.2
10500 8.9 48.0 270 15 8 5.2 2.8 15.0 59.0 -8.8 228 1.2
10250 9.4 48.9 275 15 8 7.6 4.2 14.8 58.6 -9.1 206 1.0
10000 9.9 49.8 275 14 7 7.5 4.1 14.6 58.3 -9.3 184 0.9
9750 10.4 50.7 275 14 7 7.6 4.2 14.5 58.0 -9.6 161 0.8
9500 11.0 51.8 280 13 7 8.7 4.8 14.3 57.8 -9.8 137 0.7
9250 11.6 52.9 280 10 5 10.6 5.8 14.3 57.8 -9.9 110 0.6
9000 12.3 54.1 280 6 3 7.5 4.1 14.3 57.8 -9.9 82 0.4
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 * * * * * *
07/01/2024 at 0900 MDT | 07/01/2024 at 1200 MDT
|
CAPE... +97.7 LI... -0.6 | CAPE... +670.3 LI... -2.9
CINH... -50.4 K Index... +22.5 | CINH... -1.7 K Index... +24.5
|
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 -65.0 -85.0 230 31 16 2.3 1.3 | -65.0 -85.0 235 35 18 2.5 1.4
45000 -58.7 -73.7 230 42 21 6.6 3.6 | -58.6 -73.5 230 46 24 6.5 3.5
40000 -48.4 -55.1 225 43 22 7.9 4.3 | -48.6 -55.5 230 50 26 7.5 4.1
38000 -43.7 -46.7 225 41 21 7.9 4.3 | -44.0 -47.2 225 52 27 7.5 4.1
36000 -39.0 -38.2 220 40 20 7.5 4.1 | -39.5 -39.1 225 54 28 7.6 4.2
34000 -34.6 -30.3 225 38 20 7.3 4.0 | -34.9 -30.8 225 51 26 7.6 4.2
32000 -29.7 -21.5 225 37 19 8.1 4.4 | -30.4 -22.7 225 49 25 8.7 4.8
30000 -25.4 -13.7 225 36 19 7.2 4.0 | -25.4 -13.7 230 42 22 7.5 4.1
29000 -23.3 -9.9 225 36 18 7.2 4.0 | -23.1 -9.6 230 39 20 7.5 4.1
28000 -21.2 -6.2 225 35 18 6.8 3.7 | -21.0 -5.8 230 37 19 7.1 3.9
27000 -19.2 -2.6 230 35 18 6.8 3.8 | -18.9 -2.0 235 36 19 7.1 3.9
26000 -17.2 1.0 235 34 18 6.9 3.8 | -16.8 1.8 235 36 18 7.1 3.9
25000 -15.2 4.6 235 34 18 6.7 3.7 | -14.7 5.5 240 35 18 6.7 3.7
24000 -13.3 8.1 240 34 17 6.7 3.7 | -12.8 9.0 240 34 17 6.5 3.6
23000 -11.3 11.7 240 33 17 6.7 3.7 | -10.9 12.4 240 32 17 6.5 3.6
22000 -9.4 15.1 245 32 17 6.3 3.5 | -9.0 15.8 240 31 16 5.9 3.2
21000 -7.6 18.3 250 31 16 6.1 3.3 | -7.5 18.5 245 28 14 5.4 3.0
20000 -5.8 21.6 250 30 15 6.1 3.3 | -5.9 21.4 245 25 13 5.4 3.0
19500 -4.9 23.2 255 30 15 6.1 3.3 | -5.1 22.8 250 23 12 5.4 3.0
19000 -3.9 25.0 255 28 15 7.4 4.1 | -4.4 24.1 250 22 11 4.1 2.3
18500 -2.9 26.8 255 26 13 7.3 4.0 | -3.8 25.2 255 20 11 4.3 2.4
18000 -1.8 28.8 255 24 12 6.5 3.6 | -3.2 26.2 260 19 10 5.4 3.0
17500 -1.0 30.2 260 23 12 5.9 3.2 | -2.2 28.0 265 18 9 6.4 3.5
17000 -0.1 31.8 265 22 11 5.8 3.2 | -1.3 29.7 265 16 8 6.4 3.5
16500 0.7 33.3 270 21 11 5.4 3.0 | -0.4 31.3 270 16 8 6.2 3.4
16000 1.5 34.7 275 21 11 5.5 3.0 | 0.5 32.9 265 15 8 6.2 3.4
15500 2.8 37.0 285 21 11 6.6 3.6 | 1.5 34.7 265 14 7 7.6 4.2
15000 3.7 38.7 285 22 11 6.5 3.6 | 2.6 36.7 255 13 7 8.0 4.4
14500 4.7 40.5 290 23 12 7.2 3.9 | 3.8 38.8 250 13 7 7.3 4.0
14000 5.8 42.4 290 23 12 7.4 4.0 | 4.9 40.8 250 14 7 8.2 4.5
13500 6.8 44.2 285 23 12 6.5 3.6 | 6.6 43.9 255 17 9 6.5 3.5
13000 7.7 45.9 280 22 11 6.5 3.6 | 7.6 45.7 260 18 9 6.8 3.7
12500 8.6 47.5 275 22 11 5.6 3.1 | 8.5 47.3 265 20 10 6.2 3.4
12000 9.3 48.7 270 22 11 4.9 2.7 | 9.2 48.6 270 20 10 6.5 3.6
11750 9.7 49.5 265 22 11 5.4 2.9 | 9.7 49.5 270 19 10 7.6 4.1
11500 10.0 50.0 265 22 11 4.5 2.5 | 10.2 50.4 265 18 9 7.2 4.0
11250 10.3 50.5 265 21 11 3.5 1.9 | 10.7 51.3 260 16 8 7.3 4.0
11000 10.5 50.9 260 20 10 3.3 1.8 | 11.1 52.0 255 15 8 7.0 3.8
10750 10.7 51.3 260 19 10 4.3 2.4 | 11.6 52.9 250 15 7 9.6 5.3
10500 11.1 52.0 260 18 9 6.2 3.4 | 12.4 54.3 250 14 7 11.1 6.1
10250 11.5 52.7 255 17 9 7.0 3.9 | 13.1 55.6 245 14 7 9.6 5.3
10000 12.0 53.6 255 14 7 7.4 4.0 | 13.8 56.8 245 14 7 9.9 5.5
9750 12.4 54.3 250 12 6 6.8 3.7 | 14.5 58.1 245 13 7 9.5 5.2
9500 13.0 55.4 250 11 5 12.2 6.7 | 15.3 59.5 245 13 7 13.5 7.4
9250 14.2 57.6 250 9 5 22.9 12.6 | 16.6 61.9 245 12 6 21.6 11.8
9000 15.6 60.1 250 8 4 7.2 3.9 | 17.9 64.2 245 10 5 8.9 4.9
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
07/01/2024 at 1500 MDT | 07/01/2024 at 1800 MDT
|
CAPE... +876.9 LI... -3.3 | CAPE... +556.6 LI... -2.4
CINH... 0.0 K Index... +23.4 | CINH... -1.4 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 -64.2 -83.6 240 39 20 1.9 1.0 | -64.7 -84.5 245 37 19 2.0 1.1
45000 -58.8 -73.8 235 47 24 5.9 3.2 | -58.8 -73.8 240 45 23 6.4 3.5
40000 -49.4 -56.9 225 50 26 7.9 4.3 | -48.9 -56.0 225 49 25 7.7 4.3
38000 -44.6 -48.3 225 48 25 7.9 4.3 | -44.2 -47.6 225 49 25 7.8 4.3
36000 -39.9 -39.8 220 47 24 8.4 4.6 | -39.6 -39.3 220 49 25 8.2 4.5
34000 -34.7 -30.5 225 43 22 8.6 4.7 | -34.5 -30.1 225 48 25 8.4 4.6
32000 -28.9 -20.0 230 40 20 9.1 5.0 | -28.8 -19.8 230 48 25 8.9 4.9
30000 -24.4 -11.9 235 37 19 7.7 4.2 | -24.4 -11.9 235 46 24 7.6 4.1
29000 -22.1 -7.8 235 36 18 7.7 4.2 | -22.1 -7.8 240 45 23 7.6 4.2
28000 -20.0 -4.0 240 34 18 6.6 3.6 | -20.1 -4.2 240 45 23 5.0 2.7
27000 -18.0 -0.4 245 33 17 6.8 3.7 | -18.5 -1.3 245 44 23 5.3 2.9
26000 -16.0 3.2 245 32 16 6.8 3.7 | -16.9 1.6 250 44 22 5.3 2.9
25000 -14.0 6.8 250 31 16 6.3 3.5 | -15.3 4.5 250 43 22 5.9 3.2
24000 -12.4 9.7 255 29 15 5.8 3.2 | -13.3 8.1 255 42 21 6.9 3.8
23000 -10.7 12.7 260 27 14 5.8 3.2 | -11.2 11.8 260 40 21 6.9 3.8
22000 -9.0 15.8 265 26 13 5.4 3.0 | -9.1 15.6 260 38 20 6.3 3.5
21000 -7.6 18.3 265 25 13 4.9 2.7 | -7.5 18.5 265 38 20 5.3 2.9
20000 -6.2 20.8 270 23 12 4.9 2.7 | -6.0 21.2 265 39 20 5.5 3.0
19500 -5.5 22.1 275 23 12 4.9 2.7 | -5.3 22.5 270 39 20 5.6 3.1
19000 -4.8 23.4 275 22 12 4.6 2.5 | -4.5 23.9 270 39 20 5.5 3.0
18500 -4.1 24.6 275 22 11 4.7 2.6 | -3.8 25.2 270 39 20 5.5 3.0
18000 -3.5 25.7 280 22 11 4.6 2.5 | -3.0 26.6 270 39 20 5.4 3.0
17500 -2.5 27.5 280 22 11 4.5 2.5 | -2.0 28.4 275 38 19 5.2 2.9
17000 -1.9 28.6 280 22 11 4.7 2.6 | -1.3 29.7 280 37 19 5.8 3.2
16500 -1.2 29.8 280 22 11 5.0 2.7 | -0.3 31.5 280 36 19 7.1 3.9
16000 -0.4 31.3 280 23 12 4.7 2.6 | 0.7 33.3 285 35 18 7.1 3.9
15500 0.5 32.9 285 22 11 8.0 4.4 | 1.7 35.1 285 33 17 6.5 3.6
15000 1.6 34.9 285 21 11 7.3 4.0 | 2.6 36.7 285 29 15 6.7 3.7
14500 2.9 37.2 285 20 10 9.4 5.1 | 3.5 38.3 285 26 13 7.2 3.9
14000 4.1 39.4 280 20 10 7.9 4.3 | 4.7 40.5 285 23 12 8.0 4.4
13500 5.2 41.4 280 20 10 8.2 4.5 | 5.8 42.4 280 19 10 8.6 4.7
13000 6.2 43.2 280 19 10 6.5 3.6 | 6.9 44.4 275 18 9 7.1 3.9
12500 7.2 45.0 275 18 9 6.4 3.5 | 8.0 46.4 270 17 9 7.0 3.8
12000 8.0 46.4 270 16 8 6.0 3.3 | 8.9 48.0 265 16 8 5.4 3.0
11750 8.4 47.1 265 15 8 6.1 3.4 | 9.2 48.6 260 16 8 4.7 2.6
11500 8.8 47.8 260 14 7 5.9 3.3 | 9.5 49.1 255 15 8 4.8 2.6
11250 9.2 48.6 255 14 7 5.6 3.1 | 9.8 49.6 245 15 8 4.3 2.4
11000 9.5 49.1 245 13 7 5.5 3.0 | 10.1 50.2 235 16 8 4.1 2.3
10750 9.9 49.8 240 14 7 6.0 3.3 | 10.3 50.5 225 17 9 5.0 2.7
10500 10.3 50.5 235 14 7 7.5 4.1 | 10.7 51.3 220 17 9 6.6 3.6
10250 10.9 51.6 230 13 7 9.5 5.2 | 11.2 52.2 215 17 9 9.2 5.0
10000 11.5 52.7 230 13 7 10.3 5.7 | 11.9 53.4 215 17 9 10.8 5.9
9750 12.2 54.0 225 13 7 9.5 5.2 | 12.7 54.9 215 17 9 9.6 5.3
9500 12.9 55.2 225 13 7 10.5 5.8 | 13.4 56.1 210 17 9 11.7 6.4
9250 13.7 56.7 225 11 6 14.9 8.1 | 14.5 58.1 210 15 8 19.6 10.7
9000 M M M M M M M | 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
________________________________________________________________________________
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