Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
967
UXUS97 KPUB 051230
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0630 MDT Sunday, May 5, 2024
This forecast is for Villa Grove, CO for Sunday, May 5, 2024:
If the trigger temperature of 49.7 F/9.8 C is reached...then
Thermal Soaring Index....................... Good
Maximum rate of lift........................ 995 ft/min (5.1 m/s)
Maximum height of thermals.................. 21811 ft MSL (12834 ft AGL)
Forecast maximum temperature................... 66.0 F/19.3 C
Time of trigger temperature.................... 1000 MDT
Time of overdevelopment........................ 1700 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 18462 ft MSL (9486 ft AGL)
Thermal soaring outlook for Monday 05/06....... Good
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 06:01:24 / 19:59:02 MDT
Total possible sunshine........... 13 hr 57 min 39 sec (837 min 39 sec)
Altitude of sun at 13:00:13 MDT... 68.29 degrees
Upper air data from numerical model forecast valid on 05/05/2024 at 0600 MDT
Freezing level.................. 11850 ft MSL (2873 ft AGL)
Convective condensation level... 14318 ft MSL (5341 ft AGL)
Lifted condensation level....... 17702 ft MSL (8726 ft AGL)
Lifted index.................... -2.7
K index......................... -12.6
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 -57.1 -70.8 240 36 18 -0.8 -0.4 M M M M M
45000 -58.3 -72.9 250 40 21 -1.8 -1.0 M M M M M
40000 -61.4 -78.5 255 39 20 -1.6 -0.9 M M M M M
38000 -58.1 -72.6 260 39 20 8.1 4.5 M M M M M
36000 -53.2 -63.8 265 38 20 8.1 4.5 M M M M M
34000 -48.3 -54.9 265 36 19 8.4 4.6 M M M M M
32000 -43.2 -45.8 260 32 16 8.4 4.6 M M M M M
30000 -38.2 -36.8 250 29 15 8.2 4.5 26.7 80.1 6.2 M M
29000 -35.8 -32.4 250 29 15 8.2 4.5 26.1 79.0 5.7 M M
28000 -32.7 -26.9 245 28 15 8.2 4.5 25.4 77.8 5.3 M M
27000 -30.5 -22.9 245 28 14 6.4 3.5 24.7 76.4 4.7 M M
26000 -28.5 -19.3 240 28 14 6.5 3.5 23.4 74.1 3.7 M M
25000 -26.6 -15.9 240 27 14 6.4 3.5 22.2 72.0 2.8 M M
24000 -24.6 -12.3 240 27 14 6.8 3.7 21.2 70.1 1.9 M M
23000 -22.6 -8.7 240 26 13 6.9 3.8 20.0 68.1 1.0 M M
22000 -20.5 -4.9 240 26 13 6.9 3.8 19.1 66.3 0.1 M M
21000 -18.5 -1.3 240 25 13 6.9 3.8 18.1 64.6 -0.7 1121 5.7
20000 -16.4 2.5 245 24 12 6.9 3.8 17.1 62.7 -1.6 1029 5.2
19500 -15.4 4.3 245 23 12 6.9 3.8 16.6 61.9 -2.0 984 5.0
19000 -14.4 6.1 245 23 12 6.9 3.8 16.2 61.1 -2.4 938 4.8
18500 -13.4 7.9 245 23 12 6.2 3.4 15.7 60.2 -2.9 893 4.5
18000 -12.5 9.5 245 26 13 6.1 3.3 15.1 59.1 -3.5 852 4.3
17500 -11.6 11.1 245 28 15 5.8 3.2 14.5 58.0 -4.0 810 4.1
17000 -10.8 12.6 245 31 16 4.8 2.6 13.7 56.6 -4.8 773 3.9
16500 -10.1 13.8 245 34 17 4.8 2.7 12.9 55.2 -5.6 738 3.7
16000 -9.4 15.1 245 35 18 6.2 3.4 12.2 54.0 -6.3 700 3.6
15500 -8.5 16.7 240 36 18 6.3 3.5 11.6 52.9 -7.0 659 3.3
15000 -7.6 18.3 240 36 18 8.4 4.6 11.1 52.1 -7.5 617 3.1
14500 -5.5 22.1 240 33 17 7.3 4.0 11.1 52.0 -7.8 533 2.7
14000 -4.6 23.7 235 31 16 8.9 4.9 10.6 51.1 -8.3 489 2.5
13500 -3.3 26.1 235 29 15 8.8 4.8 10.5 50.8 -8.5 435 2.2
13000 -2.0 28.4 235 27 14 8.1 4.4 10.3 50.6 -8.7 382 1.9
12500 -1.0 30.2 230 27 14 7.4 4.0 9.9 49.9 -9.2 338 1.7
12000 -0.1 31.8 230 28 14 5.1 2.8 9.5 49.1 -9.8 296 1.5
11750 0.2 32.4 225 27 14 4.6 2.5 9.1 48.3 -10.3 280 1.4
11500 0.6 33.1 225 27 14 5.3 2.9 8.7 47.7 -10.7 262 1.3
11250 0.9 33.6 225 27 14 5.1 2.8 8.4 47.0 -11.1 245 1.2
11000 1.2 34.2 220 27 14 4.6 2.5 8.0 46.4 -11.6 227 1.2
10750 1.5 34.7 220 26 13 2.9 1.6 7.5 45.6 -12.0 211 1.1
10500 1.7 35.1 215 25 13 1.8 1.0 7.0 44.5 -12.6 199 1.0
10250 1.8 35.2 210 24 12 1.7 0.9 6.4 43.5 -13.2 187 1.0
10000 1.9 35.4 205 23 12 0.6 0.3 5.7 42.3 -13.9 177 0.9
9750 1.9 35.4 205 21 11 -0.6 -0.3 5.0 41.0 -14.7 170 0.9
9500 1.8 35.2 205 19 10 -3.8 -2.1 4.1 39.4 -15.6 166 0.8
9250 1.3 34.3 205 17 9 -10.9 -6.0 2.8 37.1 -16.8 174 0.9
9000 0.3 32.5 210 7 3 -14.4 -7.9 1.1 34.0 -18.6 195 1.0
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 * * * * * *
05/05/2024 at 0900 MDT | 05/05/2024 at 1200 MDT
|
CAPE... +1.6 LI... +1.5 | CAPE... +56.5 LI... +0.7
CINH... -0.0 K Index... +2.9 | CINH... 0.0 K Index... +7.1
|
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 -57.5 -71.5 245 34 18 -1.3 -0.7 | -58.6 -73.5 250 34 17 -1.9 -1.1
45000 -59.4 -74.9 255 39 20 -1.3 -0.7 | -61.3 -78.3 255 40 20 0.6 0.3
40000 -61.4 -78.5 260 56 29 -1.0 -0.5 | -60.4 -76.7 250 62 32 0.6 0.4
38000 -58.0 -72.4 260 53 28 8.0 4.4 | -56.9 -70.4 250 62 32 7.4 4.1
36000 -53.2 -63.8 260 48 25 8.0 4.4 | -52.4 -62.3 250 60 31 7.4 4.1
34000 -48.3 -54.9 255 44 22 8.2 4.5 | -47.8 -54.0 250 57 29 8.1 4.4
32000 -43.4 -46.1 245 41 21 8.2 4.5 | -43.0 -45.4 250 52 27 8.1 4.4
30000 -38.4 -37.1 240 41 21 8.7 4.8 | -38.2 -36.8 245 48 25 8.2 4.5
29000 -35.8 -32.4 240 42 21 8.7 4.8 | -35.1 -31.2 240 47 24 8.2 4.5
28000 -32.6 -26.7 240 43 22 8.7 4.7 | -32.7 -26.9 240 47 24 8.2 4.5
27000 -30.1 -22.2 240 43 22 7.6 4.2 | -30.2 -22.4 235 46 24 8.0 4.4
26000 -27.8 -18.0 245 40 21 7.7 4.2 | -27.8 -18.0 235 45 23 8.1 4.4
25000 -25.5 -13.9 245 38 19 7.7 4.2 | -25.4 -13.7 235 44 23 8.1 4.4
24000 -23.3 -9.9 250 36 18 6.2 3.4 | -23.0 -9.4 235 43 22 8.4 4.6
23000 -21.5 -6.7 245 34 17 6.2 3.4 | -20.5 -4.9 240 41 21 8.4 4.6
22000 -19.6 -3.3 240 32 17 6.2 3.4 | -18.0 -0.4 240 39 20 8.4 4.6
21000 -17.8 -0.0 240 31 16 5.7 3.1 | -15.8 3.6 240 38 20 4.2 2.3
20000 -16.1 3.0 235 31 16 5.8 3.2 | -14.5 5.9 240 41 21 4.7 2.6
19500 -15.2 4.6 235 31 16 5.8 3.2 | -13.8 7.2 235 43 22 4.7 2.6
19000 -14.3 6.3 230 31 16 5.7 3.2 | -13.2 8.2 235 45 23 4.7 2.6
18500 -13.4 7.9 230 31 16 6.4 3.5 | -12.5 9.5 235 46 24 4.8 2.6
18000 -12.4 9.7 230 32 17 6.6 3.6 | -11.7 10.9 235 46 23 4.9 2.7
17500 -11.5 11.3 235 34 17 6.9 3.8 | -10.9 12.4 235 45 23 5.2 2.8
17000 -10.3 13.5 230 33 17 8.2 4.5 | -10.0 14.0 230 45 23 6.4 3.5
16500 -9.0 15.8 230 33 17 8.4 4.6 | -9.0 15.8 230 45 23 6.5 3.5
16000 -7.9 17.8 230 34 17 5.9 3.2 | -8.0 17.6 230 44 23 6.3 3.5
15500 -7.1 19.2 230 36 19 5.9 3.2 | -7.0 19.4 230 43 22 6.3 3.5
15000 -6.2 20.8 230 39 20 7.2 3.9 | -6.1 21.0 230 42 22 5.9 3.2
14500 -5.1 22.8 225 39 20 8.7 4.8 | -5.3 22.5 225 39 20 6.1 3.3
14000 -3.9 25.0 225 38 20 6.7 3.7 | -4.3 24.3 220 35 18 6.3 3.4
13500 -2.9 26.8 220 36 18 7.0 3.9 | -3.4 25.9 215 32 17 6.7 3.7
13000 -2.1 28.2 220 33 17 6.3 3.5 | -2.5 27.5 210 29 15 6.8 3.8
12500 -1.0 30.2 220 29 15 7.2 4.0 | -1.4 29.5 210 27 14 7.9 4.3
12000 -0.1 31.8 215 26 13 4.8 2.6 | -0.4 31.3 205 24 12 7.1 3.9
11750 0.2 32.4 215 26 13 3.7 2.0 | 0.1 32.2 205 23 12 8.7 4.8
11500 0.4 32.7 215 25 13 4.4 2.4 | 0.7 33.3 200 22 12 9.4 5.1
11250 0.7 33.3 215 25 13 4.4 2.4 | 1.4 34.5 200 22 11 9.2 5.1
11000 0.9 33.6 215 24 12 1.5 0.8 | 2.0 35.6 195 21 11 9.9 5.4
10750 0.9 33.6 215 23 12 0.5 0.3 | 2.8 37.0 195 19 10 10.5 5.7
10500 1.0 33.8 215 22 11 2.2 1.2 | 3.5 38.3 195 18 10 10.4 5.7
10250 1.1 34.0 210 21 11 2.2 1.2 | 4.3 39.7 195 18 9 10.5 5.7
10000 1.3 34.3 210 19 10 4.1 2.3 | 5.1 41.2 195 17 9 11.1 6.1
9750 1.7 35.1 205 18 9 5.9 3.2 | 5.9 42.6 195 16 8 12.2 6.7
9500 2.1 35.8 205 16 8 6.8 3.7 | 6.8 44.2 195 15 8 10.3 5.7
9250 2.8 37.0 200 14 7 13.4 7.3 | 7.7 45.9 195 14 7 17.4 9.5
9000 4.5 40.1 200 10 5 36.5 20.0 | 10.7 51.3 195 13 6 79.6 43.7
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
05/05/2024 at 1500 MDT | 05/05/2024 at 1800 MDT
|
CAPE... +11.3 LI... +1.6 | CAPE... +5.3 LI... +1.0
CINH... 0.0 K Index... +14.7 | CINH... -1.0 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 -58.6 -73.5 230 41 21 -1.8 -1.0 | -57.5 -71.5 240 33 17 -2.0 -1.1
45000 -61.1 -78.0 240 57 29 0.2 0.1 | -60.3 -76.5 240 47 24 0.4 0.2
40000 -60.7 -77.3 245 78 40 0.3 0.2 | -59.9 -75.8 245 76 39 0.4 0.2
38000 -57.1 -70.8 245 77 39 7.7 4.2 | -56.9 -70.4 240 80 41 6.7 3.7
36000 -52.5 -62.5 245 72 37 7.7 4.2 | -52.9 -63.2 240 80 41 6.7 3.7
34000 -47.8 -54.0 240 67 35 8.2 4.5 | -48.4 -55.1 240 79 41 8.8 4.8
32000 -42.9 -45.2 240 64 33 8.2 4.5 | -43.2 -45.8 240 74 38 8.7 4.8
30000 -37.9 -36.2 240 61 31 8.3 4.6 | -38.1 -36.6 235 70 36 8.2 4.5
29000 -34.8 -30.6 240 60 31 8.3 4.6 | -35.6 -32.1 235 69 35 8.1 4.5
28000 -32.3 -26.1 240 60 31 8.3 4.6 | -32.6 -26.7 235 67 34 8.2 4.5
27000 -29.9 -21.8 240 59 31 7.8 4.3 | -30.2 -22.4 235 65 33 7.8 4.3
26000 -27.6 -17.7 240 58 30 7.8 4.3 | -27.9 -18.2 235 62 32 7.8 4.3
25000 -25.3 -13.5 240 57 29 7.8 4.3 | -25.6 -14.1 235 60 31 7.8 4.3
24000 -22.9 -9.2 240 55 28 7.9 4.3 | -23.2 -9.8 235 58 30 8.1 4.4
23000 -20.6 -5.1 240 49 25 7.9 4.3 | -20.8 -5.4 235 54 28 8.1 4.4
22000 -18.3 -0.9 240 44 23 7.9 4.3 | -18.5 -1.3 235 50 26 8.1 4.5
21000 -16.1 3.0 240 41 21 5.5 3.0 | -16.2 2.8 235 47 24 5.7 3.1
20000 -14.4 6.1 240 44 23 5.7 3.2 | -14.5 5.9 230 46 24 6.0 3.3
19500 -13.6 7.5 235 46 23 5.8 3.2 | -13.6 7.5 230 46 24 6.0 3.3
19000 -12.7 9.1 235 47 24 5.9 3.2 | -12.7 9.1 230 46 23 6.1 3.3
18500 -11.9 10.6 235 48 25 4.2 2.3 | -11.9 10.6 225 45 23 4.3 2.4
18000 -11.3 11.7 230 49 25 3.9 2.2 | -11.4 11.5 220 44 23 3.8 2.1
17500 -10.7 12.7 225 49 25 4.1 2.3 | -10.8 12.6 215 43 22 4.1 2.2
17000 -10.0 14.0 225 45 23 5.1 2.8 | -10.0 14.0 215 42 22 7.0 3.9
16500 -9.3 15.3 220 40 20 4.9 2.7 | -9.0 15.8 210 41 21 6.7 3.7
16000 -8.4 16.9 215 35 18 7.6 4.1 | -7.9 17.8 205 40 20 8.5 4.7
15500 -7.4 18.7 210 32 17 7.8 4.3 | -6.6 20.1 205 38 20 8.9 4.9
15000 -6.2 20.8 200 30 15 10.0 5.5 | -5.3 22.5 205 37 19 10.2 5.6
14500 -4.5 23.9 200 29 15 11.4 6.2 | -3.6 25.5 205 37 19 11.2 6.1
14000 -2.6 27.3 200 28 15 10.1 5.6 | -1.8 28.8 205 36 18 9.9 5.4
13500 -1.1 30.0 200 28 15 10.4 5.7 | -0.2 31.6 205 35 18 10.8 5.9
13000 0.4 32.7 200 28 14 9.4 5.2 | 1.2 34.2 205 35 18 8.5 4.6
12500 1.8 35.2 200 28 14 9.7 5.3 | 2.6 36.7 205 35 18 9.5 5.2
12000 3.2 37.8 200 27 14 9.2 5.1 | 4.1 39.4 205 34 18 9.6 5.3
11750 3.9 39.0 200 27 14 10.9 6.0 | 4.8 40.6 205 34 18 9.9 5.4
11500 4.7 40.5 200 27 14 10.5 5.8 | 5.5 41.9 205 34 17 10.0 5.5
11250 5.5 41.9 200 27 14 11.0 6.0 | 6.3 43.3 205 34 17 9.8 5.4
11000 6.3 43.3 200 27 14 9.3 5.1 | 7.0 44.6 205 33 17 10.5 5.8
10750 7.0 44.6 200 27 14 9.5 5.2 | 7.8 46.0 205 33 17 10.4 5.7
10500 7.8 46.0 200 26 14 11.2 6.2 | 8.6 47.5 205 33 17 9.8 5.4
10250 8.6 47.5 200 26 13 10.7 5.9 | 9.3 48.7 205 32 16 9.8 5.4
10000 9.4 48.9 195 26 13 11.1 6.1 | 10.1 50.2 205 31 16 10.4 5.7
9750 10.3 50.5 195 25 13 11.8 6.5 | 10.9 51.6 205 30 16 11.7 6.4
9500 11.1 52.0 195 24 12 9.4 5.1 | 11.8 53.2 205 28 14 13.4 7.4
9250 11.9 53.4 195 22 11 15.9 8.7 | 12.9 55.2 205 24 12 15.0 8.3
9000 14.9 58.8 195 18 9 82.4 45.2 | 13.9 57.0 205 19 10 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