Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
308
UXUS97 KPUB 191207
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0607 MDT Saturday, October 19, 2024
This forecast is for Villa Grove, CO for Saturday, October 19, 2024:
If the trigger temperature of 49.3 F/9.6 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 77 ft/min (0.4 m/s)
Maximum height of thermals.................. 14232 ft MSL (5221 ft AGL)
Forecast maximum temperature................... 53.0 F/12.1 C
Time of trigger temperature.................... 1245 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................. 12428 ft MSL (3416 ft AGL)
Thermal soaring outlook for Sunday 10/20....... Poor
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 07:17:11 / 18:19:33 MDT
Total possible sunshine........... 11 hr 2 min 21 sec (662 min 21 sec)
Altitude of sun at 12:48:22 MDT... 41.29 degrees
Upper air data from numerical model forecast valid on 10/19/2024 at 0600 MDT
Freezing level.................. 9431 ft MSL (420 ft AGL)
Convective condensation level... 14005 ft MSL (4994 ft AGL)
Lifted condensation level....... 14217 ft MSL (5205 ft AGL)
Lifted index.................... +1.1
K index......................... +22.2
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 -60.3 -76.5 230 25 13 1.9 1.1 M M M M M
45000 -57.3 -71.1 215 32 17 1.6 0.9 M M M M M
40000 -54.9 -66.8 190 46 24 1.6 0.9 M M M M M
38000 -54.0 -65.2 180 43 22 1.6 0.9 M M M M M
36000 -53.0 -63.4 165 40 21 1.6 0.9 M M M M M
34000 -49.8 -57.6 155 37 19 9.4 5.2 M M M M M
32000 -43.4 -46.1 155 31 16 9.4 5.2 M M M M M
30000 -38.1 -36.6 155 26 14 8.6 4.7 25.9 78.6 11.2 M M
29000 -35.5 -31.9 160 24 12 8.6 4.7 25.5 77.8 10.9 M M
28000 -33.0 -27.4 165 22 11 8.6 4.7 25.1 77.2 10.8 M M
27000 -30.6 -23.1 170 20 11 7.8 4.3 24.5 76.0 10.4 M M
26000 -28.2 -18.8 175 20 10 7.8 4.3 23.7 74.6 9.8 M M
25000 -25.9 -14.6 180 19 10 7.8 4.3 23.0 73.5 9.4 M M
24000 -23.7 -10.7 185 19 10 7.4 4.1 22.3 72.1 8.8 M M
23000 -21.5 -6.7 190 19 10 7.4 4.1 21.4 70.5 8.2 M M
22000 -19.3 -2.7 195 20 10 7.4 4.1 20.7 69.2 7.6 M M
21000 -17.2 1.0 200 21 11 6.9 3.8 19.7 67.5 6.8 M M
20000 -15.2 4.6 200 21 11 6.9 3.8 18.8 65.8 6.0 M M
19500 -14.2 6.4 205 22 11 6.9 3.8 18.3 65.0 5.6 M M
19000 -13.2 8.2 205 22 11 6.9 3.8 17.9 64.2 5.2 M M
18500 -12.2 10.0 205 22 11 6.8 3.7 17.4 63.3 4.8 M M
18000 -11.2 11.8 205 22 11 6.9 3.8 16.9 62.4 4.3 M M
17500 -10.2 13.6 205 22 11 6.3 3.5 16.4 61.5 3.8 M M
17000 -8.8 16.2 205 22 11 6.3 3.5 15.5 60.0 3.0 M M
16500 -7.9 17.8 200 22 11 6.4 3.5 15.0 59.0 2.5 M M
16000 -7.0 19.4 200 22 11 6.4 3.5 14.5 58.0 2.0 M M
15500 -6.1 21.0 195 23 12 6.0 3.3 13.9 57.1 1.5 M M
15000 -5.3 22.5 190 23 12 5.8 3.2 13.3 55.9 0.8 M M
14500 -4.4 24.1 185 23 12 6.4 3.5 12.6 54.7 0.2 M M
14000 -3.6 25.5 180 20 10 4.4 2.4 12.0 53.5 -0.5 454 2.3
13500 -2.9 26.8 175 18 9 4.6 2.5 11.2 52.1 -1.2 419 2.1
13000 -2.3 27.9 165 15 8 4.1 2.3 10.3 50.6 -2.1 386 2.0
12500 -1.7 28.9 150 13 7 4.1 2.2 9.5 49.0 -3.0 353 1.8
12000 -1.3 29.7 130 12 6 2.5 1.4 8.5 47.2 -4.0 324 1.6
11750 -1.1 30.0 125 12 6 2.2 1.2 7.9 46.2 -4.5 312 1.6
11500 -0.9 30.4 115 11 6 2.0 1.1 7.3 45.2 -5.1 300 1.5
11250 -0.8 30.6 110 11 6 2.0 1.1 6.7 44.1 -5.7 288 1.5
11000 -0.6 30.9 110 10 5 2.0 1.1 6.1 43.0 -6.3 276 1.4
10750 -0.5 31.1 105 9 5 1.5 0.8 5.5 41.9 -6.9 265 1.3
10500 -0.4 31.3 105 9 4 0.7 0.4 4.9 40.7 -7.6 255 1.3
10250 -0.4 31.3 105 8 4 1.0 0.5 4.2 39.5 -8.3 246 1.2
10000 -0.3 31.5 100 6 3 1.1 0.6 3.5 38.3 -8.9 236 1.2
9750 -0.2 31.6 095 4 2 1.3 0.7 2.9 37.1 -9.6 226 1.1
9500 -0.1 31.8 080 3 1 2.3 1.2 2.3 36.1 -10.2 215 1.1
9250 0.1 32.2 045 1 1 3.1 1.7 1.7 35.1 -10.8 201 1.0
9000 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
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 * * * * * *
10/19/2024 at 0900 MDT | 10/19/2024 at 1200 MDT
|
CAPE... +1.7 LI... -0.1 | CAPE... +3.9 LI... +1.1
CINH... 0.0 K Index... +19.6 | CINH... 0.0 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 -59.1 -74.4 235 13 7 2.2 1.2 | -59.0 -74.2 210 22 11 2.2 1.2
45000 -56.2 -69.2 215 24 12 -0.0 -0.0 | -56.2 -69.2 215 37 19 -0.2 -0.1
40000 -56.2 -69.2 190 47 24 -0.3 -0.2 | -56.5 -69.7 190 43 22 -0.6 -0.4
38000 -54.8 -66.6 180 44 23 2.6 1.4 | -54.8 -66.6 175 38 20 3.3 1.8
36000 -53.3 -63.9 165 42 22 2.6 1.4 | -52.8 -63.0 155 36 18 3.3 1.8
34000 -49.6 -57.3 155 41 21 9.4 5.2 | -49.2 -56.6 150 37 19 8.5 4.7
32000 -43.9 -47.0 160 38 20 9.4 5.2 | -43.4 -46.1 165 42 21 8.5 4.7
30000 -37.9 -36.2 160 36 18 8.5 4.7 | -38.5 -37.3 170 44 23 8.0 4.4
29000 -35.4 -31.7 160 34 18 8.5 4.7 | -36.1 -33.0 170 44 23 8.0 4.4
28000 -32.8 -27.0 160 33 17 8.5 4.7 | -33.7 -28.7 175 45 23 7.9 4.4
27000 -30.4 -22.7 165 33 17 8.2 4.5 | -31.2 -24.2 175 45 23 8.6 4.7
26000 -27.9 -18.2 165 33 17 8.2 4.5 | -28.6 -19.5 170 45 23 8.6 4.7
25000 -25.5 -13.9 165 33 17 8.2 4.5 | -26.0 -14.8 170 46 23 8.7 4.7
24000 -23.2 -9.8 170 34 17 7.2 4.0 | -23.6 -10.5 170 44 23 7.9 4.4
23000 -21.1 -6.0 175 35 18 7.2 4.0 | -21.2 -6.2 170 40 21 8.0 4.4
22000 -18.9 -2.0 180 36 18 7.3 4.0 | -18.9 -2.0 165 37 19 8.2 4.5
21000 -17.1 1.2 180 34 18 5.7 3.1 | -16.7 1.9 165 33 17 7.2 4.0
20000 -15.4 4.3 185 31 16 5.7 3.1 | -14.6 5.7 165 28 15 7.3 4.0
19500 -14.6 5.7 190 29 15 5.7 3.1 | -13.5 7.7 165 26 13 7.2 3.9
19000 -13.8 7.2 190 28 14 6.3 3.4 | -12.5 9.5 165 24 12 5.6 3.1
18500 -12.7 9.1 195 25 13 7.1 3.9 | -11.9 10.6 170 23 12 3.6 2.0
18000 -11.7 10.9 200 22 11 7.0 3.8 | -11.4 11.5 175 23 12 3.4 1.9
17500 -10.6 12.9 200 19 10 8.2 4.5 | -10.8 12.6 180 23 12 4.7 2.6
17000 -9.4 15.1 200 17 9 8.1 4.5 | -10.0 14.0 185 22 11 4.6 2.5
16500 -8.2 17.2 200 14 7 8.1 4.5 | -9.3 15.3 190 22 11 6.4 3.5
16000 -7.0 19.4 195 11 6 8.1 4.4 | -8.1 17.4 195 22 11 7.5 4.1
15500 -5.8 21.6 185 8 4 7.8 4.3 | -6.4 20.5 200 23 12 8.1 4.4
15000 -4.3 24.3 165 5 3 6.4 3.5 | -5.2 22.6 200 22 11 8.2 4.5
14500 -3.4 25.9 150 4 2 5.1 2.8 | -4.1 24.6 205 21 11 7.7 4.2
14000 -3.0 26.6 145 5 3 3.1 1.7 | -2.8 27.0 205 16 8 9.4 5.2
13500 -2.6 27.3 145 7 4 3.8 2.1 | -1.5 29.3 200 10 5 8.8 4.8
13000 -1.9 28.6 150 10 5 5.2 2.8 | -0.4 31.3 170 6 3 6.3 3.5
12500 -1.2 29.8 155 13 7 4.9 2.7 | 0.4 32.7 110 6 3 5.6 3.1
12000 -0.6 30.9 150 13 7 3.8 2.1 | 1.0 33.8 095 10 5 4.5 2.5
11750 -0.3 31.5 145 13 7 3.2 1.8 | 1.3 34.3 095 11 6 3.8 2.1
11500 -0.1 31.8 140 13 7 2.3 1.2 | 1.5 34.7 095 12 6 2.8 1.5
11250 -0.0 32.0 135 13 6 0.8 0.4 | 1.6 34.9 095 13 7 1.4 0.7
11000 0.0 32.0 130 11 6 0.5 0.3 | 1.7 35.1 100 13 7 1.4 0.7
10750 0.1 32.2 120 11 5 -0.1 -0.0 | 1.8 35.2 100 13 7 0.2 0.1
10500 0.0 32.0 110 10 5 -0.6 -0.3 | 1.7 35.1 100 13 6 -1.8 -1.0
10250 0.0 32.0 100 8 4 -0.2 -0.1 | 1.6 34.9 095 11 6 -2.3 -1.3
10000 0.0 32.0 085 7 4 0.4 0.2 | 1.4 34.5 090 9 5 -1.8 -1.0
9750 0.0 32.0 065 6 3 -1.6 -0.9 | 1.2 34.2 080 8 4 -3.8 -2.1
9500 -0.1 31.8 045 7 3 2.1 1.2 | 1.1 34.0 060 6 3 4.8 2.6
9250 0.5 32.9 035 6 3 14.6 8.0 | 2.2 36.0 050 6 3 24.9 13.6
9000 1.3 34.3 025 5 3 -5.4 -2.9 | 3.4 38.1 040 5 3 -10.5 -5.8
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
10/19/2024 at 1500 MDT | 10/19/2024 at 1800 MDT
|
CAPE... +62.9 LI... -0.3 | CAPE... +206.5 LI... +0.2
CINH... -36.8 K Index... +21.0 | CINH... -53.1 K Index... +10.6
|
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 -59.8 -75.6 205 18 9 3.1 1.7 | -59.9 -75.8 205 15 8 2.2 1.2
45000 -55.7 -68.3 195 20 10 0.2 0.1 | -56.9 -70.4 180 20 10 1.0 0.6
40000 -55.4 -67.7 185 32 17 -0.0 -0.0 | -55.3 -67.5 175 28 15 0.9 0.5
38000 -53.9 -65.0 180 42 22 2.8 1.5 | -54.0 -65.2 175 41 21 2.3 1.3
36000 -52.3 -62.1 180 52 27 2.8 1.5 | -52.6 -62.7 175 54 28 2.3 1.3
34000 -49.3 -56.7 180 56 29 7.0 3.8 | -49.8 -57.6 175 57 30 7.3 4.0
32000 -44.6 -48.3 185 54 28 7.0 3.8 | -44.9 -48.8 170 50 26 7.2 4.0
30000 -39.7 -39.5 180 50 26 8.9 4.9 | -39.6 -39.3 170 46 24 9.6 5.3
29000 -37.0 -34.6 175 48 25 8.9 4.9 | -36.8 -34.2 165 44 23 9.6 5.3
28000 -34.4 -29.9 170 47 24 8.8 4.9 | -33.9 -29.0 165 43 22 9.8 5.4
27000 -31.7 -25.1 165 45 23 9.0 4.9 | -31.3 -24.3 165 41 21 8.1 4.4
26000 -29.0 -20.2 165 43 22 9.0 4.9 | -28.9 -20.0 160 40 20 8.1 4.4
25000 -26.3 -15.3 165 41 21 9.0 4.9 | -26.5 -15.7 160 38 19 8.1 4.4
24000 -23.7 -10.7 160 39 20 8.6 4.7 | -24.1 -11.4 160 36 18 8.2 4.5
23000 -21.1 -6.0 160 36 19 8.6 4.7 | -21.6 -6.9 155 34 17 8.2 4.5
22000 -18.5 -1.3 155 34 17 8.8 4.8 | -19.2 -2.6 155 32 16 8.2 4.5
21000 -16.4 2.5 155 31 16 6.0 3.3 | -16.7 1.9 155 30 16 8.1 4.4
20000 -14.7 5.5 155 28 15 6.2 3.4 | -14.3 6.3 155 29 15 8.1 4.4
19500 -13.8 7.2 155 27 14 6.3 3.5 | -13.1 8.4 155 28 14 8.0 4.4
19000 -13.0 8.6 150 26 13 7.3 4.0 | -11.9 10.6 160 27 14 7.2 3.9
18500 -11.8 10.8 150 25 13 8.2 4.5 | -10.9 12.4 160 28 14 6.4 3.5
18000 -10.6 12.9 150 24 12 8.3 4.6 | -10.0 14.0 165 28 14 6.4 3.5
17500 -9.4 15.1 150 22 11 7.9 4.3 | -9.1 15.6 165 28 15 5.6 3.0
17000 -8.3 17.1 145 21 11 8.9 4.4 | -8.4 16.9 165 28 14 5.8 3.2
16500 -7.1 19.2 140 19 10 7.6 4.2 | -7.2 19.0 170 27 14 6.0 3.3
16000 -5.5 22.1 135 17 9 7.6 4.2 | -6.3 20.7 170 25 13 6.0 3.3
15500 -4.5 23.9 130 15 8 5.0 2.7 | -5.5 22.1 170 24 12 6.2 3.4
15000 -3.8 25.2 130 14 7 4.7 2.6 | -4.6 23.7 170 22 11 6.3 3.4
14500 -3.1 26.4 135 12 6 3.6 2.0 | -3.7 25.3 170 20 10 7.2 4.0
14000 -2.6 27.3 140 10 5 4.1 2.3 | -2.4 27.7 165 18 9 9.2 5.1
13500 -2.1 28.2 155 8 4 5.6 3.1 | -1.1 30.0 160 17 9 9.5 5.2
13000 -0.9 30.4 155 6 3 7.8 4.3 | 0.2 32.4 155 16 8 7.6 4.2
12500 0.3 32.5 145 4 2 7.8 4.3 | 1.2 34.2 150 16 8 6.8 3.7
12000 1.5 34.7 110 4 2 7.2 3.9 | 2.0 35.6 145 15 8 4.7 2.6
11750 1.9 35.4 100 5 3 4.3 2.3 | 2.3 36.1 145 14 7 3.0 1.7
11500 2.1 35.8 095 6 3 2.8 1.5 | 2.4 36.3 145 14 7 3.0 1.7
11250 2.2 36.0 095 7 4 1.8 1.0 | 2.7 36.9 145 14 7 4.0 2.2
11000 2.3 36.1 105 8 4 0.9 0.5 | 2.9 37.2 145 13 7 4.1 2.2
10750 2.3 36.1 110 8 4 3.1 1.7 | 3.2 37.8 150 13 7 4.3 2.4
10500 2.6 36.7 115 9 4 6.1 3.3 | 3.5 38.3 145 13 6 5.2 2.8
10250 3.1 37.6 115 8 4 6.1 3.4 | 3.9 39.0 140 11 6 5.6 3.1
10000 3.5 38.3 110 7 3 6.7 3.6 | 4.3 39.7 135 10 5 5.8 3.2
9750 3.9 39.0 110 6 3 5.0 2.7 | 4.7 40.5 125 8 4 5.4 3.0
9500 4.3 39.7 100 4 2 10.3 5.6 | 5.1 41.2 115 7 4 6.7 3.6
9250 5.6 42.1 090 4 2 24.4 13.4 | 5.7 42.3 105 6 3 9.9 5.4
9000 7.0 44.6 080 3 2 1.8 1.0 | 6.3 43.3 095 4 2 5.1 2.8
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