Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
501
UXUS97 KPUB 061214
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0614 MDT Tuesday, May 6, 2025
This forecast is for Villa Grove, CO for Tuesday, May 6, 2025:
If the trigger temperature of 43.3 F/6.3 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 0 ft/min (0.0 m/s)
Maximum height of thermals.................. 12781 ft MSL (3836 ft AGL)
Forecast maximum temperature................... 43.0 F/6.6 C
Time of trigger temperature.................... 1415 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................. 10330 ft MSL (1384 ft AGL)
Thermal soaring outlook for Wednesday 05/07.... Poor
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 06:00:35 / 19:59:45 MDT
Total possible sunshine........... 13 hr 59 min 10 sec (839 min 10 sec)
Altitude of sun at 13:00:10 MDT... 68.50 degrees
Upper air data from numerical model forecast valid on 05/06/2025 at 0600 MDT
Freezing level.................. 9747 ft MSL (802 ft AGL)
Convective condensation level... 12308 ft MSL (3363 ft AGL)
Lifted condensation level....... 12506 ft MSL (3560 ft AGL)
Lifted index.................... +1.2
K index......................... +19.0
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 -54.9 -66.8 210 11 6 0.9 0.5 M M M M M
45000 -53.5 -64.3 220 11 6 -1.0 -0.5 M M M M M
40000 -55.8 -68.4 195 41 21 -1.5 -0.8 M M M M M
38000 -55.5 -67.9 185 54 28 2.7 1.5 M M M M M
36000 -53.9 -65.0 170 70 36 2.7 1.5 M M M M M
34000 -52.0 -61.6 165 84 43 6.5 3.6 M M M M M
32000 -48.4 -55.1 165 58 30 6.0 3.3 M M M M M
30000 -43.9 -47.0 165 33 17 8.4 4.6 19.9 67.9 10.8 M M
29000 -41.4 -42.5 160 29 15 8.5 4.7 19.4 66.9 10.5 M M
28000 -38.8 -37.8 155 24 12 8.5 4.7 18.9 66.1 10.3 M M
27000 -36.3 -33.3 145 20 11 8.2 4.5 18.6 65.5 10.1 M M
26000 -33.9 -29.0 135 21 11 8.0 4.4 17.8 64.1 9.6 M M
25000 -31.5 -24.7 125 21 11 8.0 4.4 17.2 63.0 9.2 M M
24000 -29.1 -20.4 120 22 12 8.0 4.4 16.7 62.1 8.8 M M
23000 -26.8 -16.2 115 22 11 7.7 4.2 15.9 60.6 8.3 M M
22000 -24.5 -12.1 105 21 11 7.7 4.2 15.2 59.3 7.7 M M
21000 -22.2 -8.0 100 21 11 7.0 3.9 14.6 58.2 7.2 M M
20000 -20.3 -4.5 100 21 11 6.6 3.6 13.4 56.1 6.3 M M
19500 -19.3 -2.7 100 21 11 6.6 3.6 12.9 55.2 5.8 M M
19000 -18.3 -0.9 100 21 11 6.6 3.6 12.4 54.3 5.4 M M
18500 -17.3 0.9 100 21 11 6.6 3.6 11.9 53.4 5.0 M M
18000 -16.4 2.5 100 22 11 6.6 3.6 11.4 52.5 4.5 M M
17500 -15.4 4.3 100 22 11 6.5 3.6 10.8 51.5 4.0 M M
17000 -14.4 6.1 100 22 12 7.2 3.9 10.4 50.7 3.6 M M
16500 -13.4 7.9 105 22 11 7.2 3.9 9.9 49.9 3.2 M M
16000 -12.3 9.9 105 22 11 7.1 3.9 9.5 49.1 2.8 M M
15500 -11.3 11.7 105 21 11 7.0 3.9 9.1 48.3 2.4 M M
15000 -10.3 13.5 105 21 11 7.4 4.1 8.6 47.5 2.0 M M
14500 -9.1 15.6 105 20 10 8.8 4.8 8.4 47.1 1.7 M M
14000 -8.0 17.6 105 20 10 5.0 2.8 8.0 46.4 1.3 M M
13500 -6.6 20.1 105 19 10 7.3 4.0 7.2 45.0 0.5 M M
13000 -5.6 21.9 110 19 10 6.8 3.7 6.8 44.3 0.1 M M
12500 -4.5 23.9 110 18 9 6.8 3.7 6.4 43.5 -0.4 338 1.7
12000 -3.5 25.7 110 18 9 4.6 2.5 6.0 42.7 -0.8 293 1.5
11750 -3.3 26.1 110 17 9 4.5 2.5 5.5 41.8 -1.3 279 1.4
11500 -2.8 27.0 105 17 9 7.4 4.0 5.2 41.4 -1.6 257 1.3
11250 -2.4 27.7 100 17 9 7.1 3.9 5.0 41.0 -1.8 235 1.2
11000 -1.9 28.6 095 16 8 5.3 2.9 4.8 40.6 -2.1 213 1.1
10750 -1.6 29.1 090 16 8 4.3 2.4 4.4 39.8 -2.5 197 1.0
10500 -1.2 29.8 085 15 8 5.9 3.2 4.0 39.2 -2.9 178 0.9
10250 -0.8 30.6 080 14 7 5.6 3.1 3.7 38.7 -3.2 158 0.8
10000 -0.4 31.3 070 14 7 6.3 3.4 3.4 38.2 -3.5 139 0.7
9750 0.1 32.2 065 14 7 7.0 3.8 3.2 37.8 -3.8 117 0.6
9500 0.6 33.1 065 13 7 7.4 4.1 3.0 37.4 -4.0 94 0.5
9250 1.2 34.2 060 11 6 9.4 5.2 2.9 37.2 -4.2 69 0.4
9000 2.0 35.6 055 8 4 13.5 7.4 3.0 37.4 -4.1 37 0.2
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 * * * * * *
05/06/2025 at 0900 MDT | 05/06/2025 at 1200 MDT
|
CAPE... +22.9 LI... +0.9 | CAPE... +26.3 LI... +0.6
CINH... -0.5 K Index... +19.5 | CINH... 0.0 K Index... +16.9
|
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 -55.4 -67.7 200 14 7 0.9 0.5 | -54.9 -66.8 180 16 8 1.1 0.6
45000 -54.1 -65.4 180 16 8 0.8 0.4 | -53.2 -63.8 160 20 10 0.6 0.3
40000 -53.1 -63.6 190 28 14 0.7 0.4 | -52.8 -63.0 160 13 7 0.3 0.2
38000 -53.1 -63.6 175 36 19 -0.8 -0.4 | -53.0 -63.4 140 21 11 -0.9 -0.5
36000 -53.5 -64.3 155 52 27 -0.8 -0.4 | -53.5 -64.3 130 40 21 -0.9 -0.5
34000 -53.4 -64.1 145 66 34 8.9 4.9 | -52.8 -63.0 125 54 28 8.8 4.8
32000 -48.2 -54.8 140 48 25 7.7 4.2 | -47.6 -53.7 120 44 23 8.7 4.8
30000 -43.4 -46.1 135 34 17 8.3 4.6 | -42.5 -44.5 110 35 18 8.2 4.5
29000 -40.9 -41.6 130 29 15 8.4 4.6 | -40.0 -40.0 105 34 17 8.3 4.5
28000 -38.4 -37.1 125 25 13 8.4 4.6 | -37.5 -35.5 095 32 17 8.3 4.5
27000 -35.9 -32.6 115 22 11 8.1 4.4 | -35.1 -31.2 085 32 16 8.1 4.4
26000 -33.5 -28.3 115 22 11 7.9 4.4 | -32.3 -26.1 090 31 16 7.4 4.1
25000 -31.2 -24.2 115 22 11 7.9 4.4 | -30.1 -22.2 090 30 15 7.4 4.1
24000 -28.8 -19.8 115 22 11 8.0 4.4 | -27.9 -18.2 095 29 15 7.1 3.9
23000 -26.4 -15.5 115 21 11 8.0 4.4 | -25.9 -14.6 090 28 15 6.8 3.7
22000 -24.0 -11.2 120 19 10 8.0 4.4 | -23.9 -11.0 085 27 14 6.8 3.7
21000 -21.7 -7.1 120 19 10 7.7 4.2 | -21.9 -7.4 080 27 14 7.0 3.8
20000 -19.4 -2.9 115 22 11 7.6 4.2 | -19.8 -3.6 080 29 15 7.1 3.9
19500 -18.3 -0.9 115 23 12 7.6 4.2 | -18.7 -1.7 080 30 15 7.1 3.9
19000 -17.2 1.0 115 25 13 7.6 4.2 | -17.7 0.1 080 30 16 7.1 3.9
18500 -16.1 3.0 115 26 13 7.1 3.9 | -16.7 1.9 080 31 16 7.0 3.9
18000 -15.1 4.8 110 27 14 6.3 3.4 | -15.6 3.9 080 32 16 7.0 3.8
17500 -14.2 6.4 110 27 14 6.3 3.5 | -14.6 5.7 080 32 17 7.0 3.8
17000 -13.3 8.1 105 28 14 5.7 3.2 | -13.6 7.5 080 32 17 6.8 3.7
16500 -12.5 9.5 100 29 15 5.8 3.2 | -12.6 9.3 080 33 17 6.8 3.7
16000 -11.6 11.1 095 29 15 5.9 3.2 | -11.7 10.9 085 33 17 6.1 3.4
15500 -10.7 12.7 095 29 15 6.0 3.3 | -10.8 12.6 085 34 17 6.0 3.3
15000 -9.9 14.2 090 30 15 6.4 3.5 | -9.9 14.2 085 34 17 6.3 3.5
14500 -8.3 17.1 085 30 16 6.5 3.6 | -9.0 15.8 085 34 17 7.1 3.9
14000 -7.6 18.3 080 31 16 4.9 2.7 | -8.1 17.4 085 34 17 4.3 2.4
13500 -6.8 19.8 075 31 16 5.4 3.0 | -7.4 18.7 090 34 18 6.1 3.4
13000 -6.0 21.2 075 32 17 5.7 3.1 | -6.5 20.3 090 34 18 7.2 4.0
12500 -5.2 22.6 070 32 17 5.4 2.9 | -5.6 21.9 090 35 18 5.1 2.8
12000 -4.4 24.1 070 32 17 5.0 2.7 | -4.4 24.1 090 34 18 3.1 1.7
11750 -4.0 24.8 065 32 16 6.2 3.4 | -4.3 24.3 090 33 17 2.0 1.1
11500 -3.5 25.7 065 31 16 7.5 4.1 | -4.1 24.6 090 31 16 3.6 2.0
11250 -3.0 26.6 065 30 16 7.6 4.2 | -3.8 25.2 090 30 15 3.3 1.8
11000 -2.5 27.5 065 29 15 6.1 3.3 | -3.6 25.5 085 28 14 2.9 1.6
10750 -2.1 28.2 065 29 15 5.8 3.2 | -3.3 26.1 085 26 14 5.0 2.8
10500 -1.6 29.1 065 28 14 7.4 4.1 | -2.8 27.0 085 25 13 7.9 4.3
10250 -1.1 30.0 065 27 14 7.6 4.2 | -2.3 27.9 085 23 12 7.9 4.3
10000 -0.5 31.1 065 26 13 6.6 3.6 | -1.7 28.9 080 21 11 8.1 4.4
9750 -0.1 31.8 065 24 12 5.8 3.2 | -1.1 30.0 080 20 10 8.7 4.8
9500 0.3 32.5 060 21 11 5.8 3.2 | -0.4 31.3 080 18 9 10.2 5.6
9250 0.8 33.4 060 18 9 7.9 4.3 | 0.5 32.9 075 16 8 16.1 8.8
9000 1.9 35.4 055 11 6 27.6 15.1 | 2.2 36.0 070 11 6 34.4 18.9
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
05/06/2025 at 1500 MDT | 05/06/2025 at 1800 MDT
|
CAPE... +26.3 LI... +0.5 | CAPE... +21.4 LI... +3.2
CINH... 0.0 K Index... +14.5 | CINH... 0.0 K Index... +13.4
|
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 -54.2 -65.6 185 18 9 1.6 0.9 | -54.3 -65.7 215 15 8 1.2 0.7
45000 -51.9 -61.4 170 18 9 -0.3 -0.2 | -52.5 -62.5 195 13 7 -0.1 -0.1
40000 -53.9 -65.0 125 18 9 -1.3 -0.7 | -53.6 -64.5 090 16 8 -0.7 -0.4
38000 -54.0 -65.2 115 28 14 0.8 0.4 | -53.7 -64.7 080 26 14 0.4 0.2
36000 -53.5 -64.3 110 44 23 0.8 0.4 | -53.4 -64.1 075 39 20 0.4 0.2
34000 -52.1 -61.8 105 54 28 8.4 4.6 | -52.2 -62.0 070 49 25 8.8 4.8
32000 -47.3 -53.1 095 40 20 8.1 4.5 | -47.1 -52.8 065 42 22 8.6 4.7
30000 -42.4 -44.3 080 29 15 8.4 4.6 | -42.2 -44.0 065 36 19 6.9 3.8
29000 -39.8 -39.6 085 28 15 8.5 4.6 | -40.1 -40.2 065 33 17 7.0 3.8
28000 -37.3 -35.1 085 27 14 8.5 4.6 | -38.0 -36.4 060 29 15 7.0 3.8
27000 -34.8 -30.6 085 26 13 8.3 4.6 | -35.9 -32.6 060 26 13 7.1 3.9
26000 -32.0 -25.6 090 27 14 7.4 4.0 | -33.2 -27.8 070 22 11 7.3 4.0
25000 -29.8 -21.6 090 29 15 7.4 4.0 | -31.0 -23.8 085 20 11 7.4 4.0
24000 -27.6 -17.7 090 30 16 7.1 3.9 | -28.8 -19.8 100 20 10 7.5 4.1
23000 -25.7 -14.3 095 33 17 6.5 3.6 | -26.5 -15.7 100 20 10 7.6 4.2
22000 -23.7 -10.7 095 35 18 6.6 3.6 | -24.3 -11.7 105 20 10 7.6 4.2
21000 -21.8 -7.2 095 38 19 6.1 3.4 | -22.0 -7.6 105 20 10 7.0 3.9
20000 -20.0 -4.0 095 38 19 6.0 3.3 | -20.0 -4.0 105 20 10 6.9 3.8
19500 -19.1 -2.4 090 38 20 6.0 3.3 | -19.0 -2.2 105 20 10 6.9 3.8
19000 -18.3 -0.9 090 38 20 6.0 3.3 | -18.0 -0.4 105 20 10 6.8 3.8
18500 -17.4 0.7 090 38 20 6.4 3.5 | -17.0 1.4 105 20 10 6.2 3.4
18000 -16.4 2.5 085 37 19 6.8 3.8 | -16.2 2.8 100 20 10 5.5 3.0
17500 -15.4 4.3 085 35 18 6.9 3.8 | -15.4 4.3 100 21 11 5.7 3.1
17000 -14.4 6.1 085 34 18 6.6 3.6 | -14.7 5.5 095 23 12 3.0 1.6
16500 -13.4 7.9 080 34 17 6.6 3.6 | -14.3 6.3 090 25 13 3.2 1.8
16000 -12.4 9.7 080 33 17 6.5 3.6 | -13.8 7.2 085 28 14 3.7 2.0
15500 -11.5 11.3 075 33 17 6.4 3.5 | -13.2 8.2 085 31 16 3.9 2.2
15000 -10.6 12.9 075 33 17 6.0 3.3 | -12.6 9.3 080 34 17 5.4 3.0
14500 -9.8 14.4 075 33 17 5.3 2.9 | -11.6 11.1 080 35 18 7.7 4.2
14000 -9.1 15.6 080 33 17 3.5 1.9 | -10.5 13.1 080 36 19 6.4 3.5
13500 -8.5 16.7 080 33 17 5.0 2.7 | -9.6 14.7 075 36 19 6.2 3.4
13000 -7.8 18.0 080 33 17 4.7 2.6 | -8.7 16.3 075 36 19 6.6 3.6
12500 -6.8 19.8 085 30 16 4.6 2.5 | -7.4 18.7 075 34 18 5.8 3.2
12000 -6.1 21.0 085 28 14 3.6 2.0 | -6.6 20.1 075 32 17 5.0 2.7
11750 -5.9 21.4 080 26 14 3.9 2.1 | -6.2 20.8 070 31 16 5.6 3.1
11500 -5.5 22.1 080 25 13 5.1 2.8 | -5.8 21.6 070 29 15 6.6 3.6
11250 -5.2 22.6 080 23 12 4.9 2.7 | -5.3 22.5 065 28 14 6.3 3.5
11000 -4.8 23.4 080 21 11 4.3 2.4 | -4.9 23.2 065 27 14 5.4 3.0
10750 -4.5 23.9 075 21 11 5.5 3.0 | -4.5 23.9 065 26 14 5.5 3.0
10500 -4.0 24.8 070 19 10 7.7 4.2 | -4.0 24.8 065 25 13 6.6 3.6
10250 -3.5 25.7 065 18 9 7.8 4.3 | -3.6 25.5 065 24 12 6.8 3.7
10000 -2.9 26.8 060 17 9 8.3 4.6 | -3.1 26.4 060 22 11 7.0 3.9
9750 -2.3 27.9 060 15 8 9.1 5.0 | -2.6 27.3 060 20 10 7.4 4.1
9500 -1.6 29.1 055 14 7 9.7 5.3 | -2.0 28.4 060 17 9 9.2 5.0
9250 -0.7 30.7 055 12 6 16.2 8.9 | -1.2 29.8 060 14 7 14.0 7.7
9000 1.4 34.5 050 9 5 47.9 26.3 | 0.1 32.2 055 8 4 21.8 12.0
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