Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
350
UXUS97 KPUB 041218
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0618 MDT Saturday, October 4, 2025
This forecast is for Villa Grove, CO for Saturday, October 4, 2025:
If the trigger temperature of 57.2 F/14.0 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 247 ft/min (1.3 m/s)
Maximum height of thermals.................. 16032 ft MSL (7059 ft AGL)
Forecast maximum temperature................... 64.0 F/18.2 C
Time of trigger temperature.................... 0945 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ More than 30 mph
Height of the -3 thermal index................. 13333 ft MSL (4360 ft AGL)
Thermal soaring outlook for Sunday 10/05....... Fair
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 07:02:38 / 18:41:37 MDT
Total possible sunshine........... 11 hr 38 min 59 sec (698 min 59 sec)
Altitude of sun at 12:52:08 MDT... 47.03 degrees
Upper air data from numerical model forecast valid on 10/04/2025 at 0600 MDT
Freezing level.................. 14345 ft MSL (5372 ft AGL)
Convective condensation level... 15674 ft MSL (6701 ft AGL)
Lifted condensation level....... 15909 ft MSL (6936 ft AGL)
Lifted index.................... -1.4
K index......................... +12.4
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 -65.2 -85.4 230 50 26 1.5 0.8 M M M M M
45000 -61.8 -79.2 225 78 40 5.0 2.7 M M M M M
40000 -54.2 -65.6 220 88 45 6.1 3.3 M M M M M
38000 -50.3 -58.5 220 83 43 6.6 3.6 M M M M M
36000 -46.3 -51.3 215 78 40 6.6 3.6 M M M M M
34000 -42.7 -44.9 215 68 35 5.6 3.1 M M M M M
32000 -38.9 -38.0 220 55 28 5.7 3.1 M M M M M
30000 -34.4 -29.9 220 49 25 8.5 4.6 29.5 85.1 9.2 M M
29000 -31.9 -25.4 225 47 24 8.5 4.6 29.0 84.2 9.0 M M
28000 -29.3 -20.7 225 45 23 8.5 4.7 28.6 83.5 8.8 M M
27000 -26.9 -16.4 225 42 22 8.0 4.4 28.0 82.3 8.3 M M
26000 -24.5 -12.1 225 39 20 8.0 4.4 27.3 81.1 7.9 M M
25000 -22.1 -7.8 225 36 19 8.0 4.4 26.7 80.1 7.5 M M
24000 -19.6 -3.3 220 33 17 8.6 4.7 26.2 79.2 7.2 M M
23000 -17.0 1.4 220 31 16 8.6 4.7 25.8 78.4 6.9 M M
22000 -14.4 6.1 220 28 15 8.7 4.8 25.5 77.8 6.6 M M
21000 -12.2 10.0 220 29 15 6.5 3.5 24.6 76.3 6.0 M M
20000 -10.3 13.5 220 32 16 6.5 3.6 23.5 74.2 4.9 M M
19500 -9.4 15.1 220 33 17 6.5 3.6 22.9 73.3 4.5 M M
19000 -8.4 16.9 220 34 18 6.3 3.5 22.5 72.4 4.0 M M
18500 -7.7 18.1 220 36 18 5.2 2.9 21.7 71.1 3.4 M M
18000 -6.9 19.6 220 37 19 5.3 2.9 21.0 69.8 2.6 M M
17500 -6.2 20.8 215 38 20 5.6 3.1 20.3 68.5 2.0 M M
17000 -5.4 22.3 215 40 20 5.7 3.1 19.6 67.3 1.3 M M
16500 -4.6 23.7 215 41 21 6.1 3.3 19.0 66.1 0.6 M M
16000 -3.6 25.5 215 42 22 6.9 3.8 18.5 65.2 0.1 M M
15500 -2.2 28.0 215 43 22 7.2 4.0 17.8 64.0 -0.6 589 3.0
15000 -1.1 30.0 215 44 22 7.5 4.1 17.4 63.3 -1.1 542 2.8
14500 -0.1 31.8 215 44 23 5.7 3.1 17.0 62.7 -1.5 496 2.5
14000 0.7 33.3 220 44 23 5.9 3.3 16.3 61.3 -2.2 459 2.3
13500 1.5 34.7 220 45 23 5.8 3.2 15.7 60.2 -2.9 420 2.1
13000 2.1 35.8 220 45 23 3.8 2.1 14.8 58.7 -3.7 386 2.0
12500 2.7 36.9 225 45 23 4.1 2.2 14.0 57.2 -4.6 353 1.8
12000 3.5 38.3 225 44 23 6.2 3.4 13.2 55.8 -5.3 316 1.6
11750 3.9 39.0 225 43 22 6.7 3.7 13.0 55.4 -5.6 294 1.5
11500 4.4 39.9 225 41 21 6.7 3.7 12.7 54.9 -5.9 272 1.4
11250 4.9 40.8 225 40 20 6.9 3.8 12.5 54.5 -6.1 250 1.3
11000 5.5 41.9 225 38 19 7.7 4.2 12.3 54.2 -6.3 226 1.2
10750 6.0 42.8 225 36 18 6.6 3.6 12.1 53.9 -6.5 203 1.0
10500 6.4 43.5 225 33 17 6.4 3.5 11.9 53.4 -6.8 183 0.9
10250 6.9 44.4 225 30 16 3.6 2.0 11.6 52.8 -7.2 162 0.8
10000 6.9 44.4 220 27 14 -0.4 -0.2 10.9 51.6 -7.9 154 0.8
9750 6.8 44.2 220 24 12 -0.7 -0.4 10.1 50.2 -8.7 149 0.8
9500 6.7 44.1 220 20 10 -0.1 -0.0 9.3 48.8 -9.5 144 0.7
9250 6.6 43.9 220 16 8 -5.4 -3.0 8.5 47.3 -10.4 141 0.7
9000 5.0 41.0 220 7 4 -47.3 -26.0 6.2 43.1 -12.7 180 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 * * * * * *
10/04/2025 at 0900 MDT | 10/04/2025 at 1200 MDT
|
CAPE... 0.0 LI... +1.3 | CAPE... +106.4 LI... -0.0
CINH... 0.0 K Index... +14.8 | CINH... -3.7 K Index... +17.0
|
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 -63.5 -82.3 235 47 24 1.3 0.7 | -62.5 -80.5 235 46 24 1.5 0.8
45000 -60.6 -77.1 225 74 38 4.3 2.4 | -59.4 -74.9 230 75 38 4.4 2.4
40000 -54.1 -65.4 220 80 41 4.6 2.5 | -52.8 -63.0 220 81 42 4.4 2.4
38000 -51.1 -60.0 220 75 39 5.0 2.7 | -50.2 -58.4 220 80 41 4.3 2.4
36000 -48.1 -54.6 220 70 36 4.9 2.7 | -47.6 -53.7 220 79 41 4.3 2.4
34000 -44.5 -48.1 220 64 33 6.9 3.8 | -43.7 -46.7 215 75 39 6.8 3.8
32000 -39.8 -39.6 215 56 29 6.9 3.8 | -39.6 -39.3 215 70 36 6.8 3.7
30000 -35.0 -31.0 215 53 27 8.6 4.7 | -35.0 -31.0 210 67 34 8.0 4.4
29000 -32.4 -26.3 215 52 27 8.6 4.7 | -32.6 -26.7 210 66 34 8.0 4.4
28000 -29.8 -21.6 215 51 26 8.7 4.8 | -30.2 -22.4 210 65 33 8.0 4.4
27000 -27.3 -17.1 215 49 25 8.2 4.5 | -27.8 -18.0 210 63 33 8.0 4.4
26000 -24.8 -12.6 215 47 24 8.3 4.5 | -25.4 -13.7 210 62 32 8.0 4.4
25000 -22.3 -8.1 215 44 23 8.3 4.5 | -23.0 -9.4 210 60 31 8.0 4.4
24000 -19.9 -3.8 215 42 22 8.2 4.5 | -20.7 -5.3 210 58 30 7.5 4.1
23000 -17.4 0.7 210 41 21 8.3 4.5 | -18.4 -1.1 210 56 29 7.5 4.1
22000 -14.9 5.2 210 40 20 8.3 4.5 | -16.1 3.0 205 55 28 7.5 4.1
21000 -12.7 9.1 205 39 20 6.8 3.7 | -14.0 6.8 205 52 27 6.6 3.6
20000 -10.7 12.7 205 38 20 6.8 3.7 | -12.1 10.2 205 48 25 6.7 3.7
19500 -9.7 14.5 205 38 19 6.9 3.8 | -11.1 12.0 205 46 24 6.8 3.7
19000 -8.7 16.3 200 37 19 6.9 3.8 | -10.2 13.6 205 44 23 7.0 3.8
18500 -7.8 18.0 200 38 19 6.2 3.4 | -9.2 15.4 205 44 23 5.9 3.2
18000 -6.9 19.6 200 38 20 6.3 3.5 | -8.4 16.9 205 45 23 6.0 3.3
17500 -6.1 21.0 200 38 20 5.5 3.0 | -7.5 18.5 205 46 24 6.2 3.4
17000 -5.3 22.5 200 39 20 5.2 2.9 | -6.6 20.1 210 47 24 6.4 3.5
16500 -4.6 23.7 200 41 21 5.4 3.0 | -5.7 21.7 210 48 25 6.4 3.5
16000 -3.8 25.2 205 42 21 6.1 3.3 | -4.4 24.1 210 48 25 6.3 3.5
15500 -2.5 27.5 205 43 22 6.4 3.5 | -3.5 25.7 210 48 25 6.5 3.5
15000 -1.6 29.1 205 44 23 6.7 3.7 | -2.5 27.5 215 47 24 6.9 3.8
14500 -0.7 30.7 205 45 23 4.8 2.6 | -1.6 29.1 215 45 23 4.9 2.7
14000 0.1 32.2 205 44 23 6.7 3.7 | -0.8 30.6 215 43 22 7.0 3.9
13500 0.9 33.6 210 43 22 6.3 3.5 | 0.1 32.2 215 42 22 6.7 3.7
13000 1.8 35.2 210 43 22 5.5 3.0 | 1.0 33.8 215 42 22 6.2 3.4
12500 2.5 36.5 215 44 22 5.0 2.8 | 1.9 35.4 215 40 21 6.3 3.4
12000 3.2 37.8 215 43 22 4.9 2.7 | 2.7 36.9 210 37 19 6.8 3.7
11750 3.6 38.5 215 42 22 5.6 3.1 | 3.3 37.9 210 34 18 8.5 4.7
11500 4.0 39.2 215 42 21 5.7 3.1 | 4.0 39.2 210 32 16 8.2 4.5
11250 4.5 40.1 215 41 21 5.3 2.9 | 4.6 40.3 210 29 15 8.7 4.8
11000 4.8 40.6 215 39 20 4.9 2.7 | 5.3 41.5 210 28 14 10.2 5.6
10750 5.2 41.4 215 36 19 3.8 2.1 | 6.1 43.0 210 27 14 10.6 5.8
10500 5.4 41.7 215 33 17 2.9 1.6 | 6.8 44.2 210 27 14 10.2 5.6
10250 5.6 42.1 215 29 15 2.8 1.5 | 7.6 45.7 210 26 13 10.6 5.8
10000 5.8 42.4 215 26 13 2.1 1.1 | 8.4 47.1 210 25 13 11.3 6.2
9750 6.0 42.8 215 23 12 2.6 1.4 | 9.3 48.7 210 24 12 12.2 6.7
9500 6.2 43.2 215 19 10 4.6 2.5 | 10.2 50.4 210 23 12 11.6 6.4
9250 6.7 44.1 215 15 8 11.3 6.2 | 11.2 52.2 210 21 11 18.2 10.0
9000 8.3 46.9 215 10 5 34.6 19.0 | 14.0 57.2 210 17 9 67.0 36.7
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
10/04/2025 at 1500 MDT | 10/04/2025 at 1800 MDT
|
CAPE... +405.3 LI... -2.6 | CAPE... +172.5 LI... -1.3
CINH... -0.1 K Index... +25.5 | CINH... -3.2 K Index... -0.1
|
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 -62.5 -80.5 235 40 21 3.0 1.6 | -61.3 -78.3 245 38 20 2.2 1.2
45000 -57.6 -71.7 230 60 31 4.5 2.5 | -57.0 -70.6 245 46 24 5.6 3.1
40000 -50.8 -59.4 225 75 39 4.5 2.4 | -48.6 -55.5 235 58 30 5.7 3.1
38000 -48.5 -55.3 225 79 41 3.8 2.1 | -46.6 -51.9 230 66 34 3.0 1.7
36000 -46.2 -51.2 220 84 43 3.8 2.1 | -44.8 -48.6 230 74 38 3.0 1.7
34000 -43.4 -46.1 220 86 44 5.8 3.2 | -42.3 -44.1 230 81 41 5.9 3.3
32000 -39.4 -38.9 220 86 44 5.8 3.2 | -38.3 -36.9 230 86 44 5.9 3.3
30000 -35.4 -31.7 215 84 43 7.6 4.2 | -34.4 -29.9 230 87 45 6.9 3.8
29000 -33.1 -27.6 215 82 42 7.6 4.2 | -32.3 -26.1 225 86 44 6.9 3.8
28000 -30.8 -23.4 215 80 41 7.6 4.2 | -30.2 -22.4 225 86 44 6.9 3.8
27000 -28.5 -19.3 215 78 40 7.5 4.1 | -28.4 -19.1 225 84 43 4.0 2.2
26000 -26.3 -15.3 215 76 39 7.5 4.1 | -27.2 -17.0 220 81 42 4.2 2.3
25000 -24.0 -11.2 210 74 38 7.5 4.1 | -25.9 -14.6 220 79 40 4.2 2.3
24000 -21.9 -7.4 210 72 37 6.7 3.7 | -24.6 -12.3 220 75 39 5.8 3.2
23000 -19.9 -3.8 210 69 36 6.8 3.7 | -22.8 -9.0 220 70 36 6.0 3.3
22000 -17.9 -0.2 215 67 34 6.9 3.8 | -21.0 -5.8 220 65 34 6.0 3.3
21000 -16.0 3.2 215 63 33 6.3 3.5 | -19.0 -2.2 220 62 32 8.1 4.5
20000 -14.1 6.6 215 58 30 6.4 3.5 | -16.6 2.1 220 62 32 7.9 4.4
19500 -13.2 8.2 215 55 29 6.4 3.5 | -15.4 4.3 220 62 32 8.0 4.4
19000 -12.3 9.9 215 53 27 6.2 3.4 | -14.2 6.4 220 62 32 8.0 4.4
18500 -11.3 11.7 215 50 26 8.0 4.4 | -13.1 8.4 220 62 32 7.3 4.0
18000 -10.1 13.8 215 48 25 7.9 4.3 | -12.0 10.4 220 62 32 7.3 4.0
17500 -9.0 15.8 215 45 23 7.5 4.1 | -11.0 12.2 220 63 32 7.5 4.1
17000 -7.9 17.8 215 44 23 7.0 3.9 | -9.8 14.4 220 61 32 7.9 4.4
16500 -6.9 19.6 215 43 22 7.0 3.9 | -8.7 16.3 220 60 31 8.1 4.4
16000 -5.9 21.4 215 42 22 6.8 3.7 | -7.6 18.3 220 58 30 6.8 3.7
15500 -4.9 23.2 215 41 21 6.8 3.7 | -6.6 20.1 225 57 29 6.8 3.8
15000 -3.9 25.0 215 40 21 7.6 4.1 | -5.6 21.9 225 55 28 8.5 4.7
14500 -2.8 27.0 215 38 19 7.8 4.3 | -3.6 25.5 230 51 26 7.3 4.0
14000 -1.4 29.5 215 34 18 8.6 4.7 | -2.6 27.3 230 49 25 8.7 4.8
13500 -0.2 31.6 215 32 17 8.1 4.4 | -1.4 29.5 230 46 23 8.6 4.7
13000 1.0 33.8 215 31 16 9.7 5.3 | -0.1 31.8 230 43 22 8.9 4.9
12500 2.4 36.3 215 31 16 9.5 5.2 | 1.2 34.2 230 41 21 9.0 4.9
12000 3.8 38.8 215 30 16 9.5 5.2 | 2.4 36.3 230 39 20 9.0 5.0
11750 4.6 40.3 215 30 16 10.3 5.7 | 3.1 37.6 230 39 20 10.3 5.6
11500 5.3 41.5 215 30 15 10.1 5.6 | 3.9 39.0 230 38 19 10.2 5.6
11250 6.1 43.0 215 30 15 10.2 5.6 | 4.7 40.5 230 37 19 10.3 5.6
11000 6.8 44.2 215 30 15 9.5 5.2 | 5.4 41.7 225 36 19 9.0 4.9
10750 7.5 45.5 215 29 15 10.1 5.5 | 6.0 42.8 225 36 18 9.3 5.1
10500 8.3 46.9 215 29 15 11.1 6.1 | 6.8 44.2 225 35 18 10.6 5.8
10250 9.2 48.6 215 29 15 10.8 5.9 | 7.5 45.5 225 34 18 10.3 5.6
10000 10.0 50.0 215 28 15 10.6 5.8 | 8.3 46.9 225 33 17 9.4 5.1
9750 10.7 51.3 215 27 14 10.8 5.9 | 9.0 48.2 225 32 16 8.8 4.8
9500 11.6 52.9 215 26 13 10.7 5.9 | 9.6 49.3 225 30 15 9.6 5.2
9250 12.4 54.3 215 24 12 15.2 8.4 | 10.4 50.7 225 27 14 10.5 5.8
9000 14.5 58.1 215 19 10 48.9 26.8 | 11.2 52.2 220 18 10 14.5 8.0
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