Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
991
UXUS97 KPUB 231315
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0615 MST Saturday, November 23, 2024
This forecast is for Villa Grove, CO for Saturday, November 23, 2024:
If the trigger temperature of 56.5 F/13.6 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 104 ft/min (0.5 m/s)
Maximum height of thermals.................. 10539 ft MSL (1550 ft AGL)
Forecast maximum temperature................... 50.0 F/10.5 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9914 ft MSL (925 ft AGL)
Thermal soaring outlook for Sunday 11/24....... Poor
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 06:54:17 / 16:46:05 MST
Total possible sunshine........... 9 hr 51 min 48 sec (591 min 48 sec)
Altitude of sun at 11:50:11 MST... 31.13 degrees
Upper air data from numerical model forecast valid on 11/23/2024 at 0500 MST
Freezing level.................. 9174 ft MSL (185 ft AGL)
Additional freezing level....... 13867 ft MSL (4878 ft AGL)
Convective condensation level... 29372 ft MSL (20383 ft AGL)
Lifted condensation level....... 23809 ft MSL (14819 ft AGL)
Lifted index.................... +11.5
K index......................... -31.4
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 -66.7 -88.1 285 58 30 0.4 0.2 M M M M M
45000 -65.9 -86.6 280 65 34 2.2 1.2 M M M M M
40000 -62.8 -81.0 295 78 40 2.1 1.1 M M M M M
38000 -58.9 -74.0 295 68 35 7.5 4.1 M M M M M
36000 -54.4 -65.9 295 55 28 7.5 4.1 M M M M M
34000 -48.7 -55.7 295 46 24 9.2 5.0 M M M M M
32000 -43.2 -45.8 295 44 23 9.2 5.0 M M M M M
30000 -37.8 -36.0 290 41 21 8.8 4.8 26.0 78.7 12.5 M M
29000 -35.2 -31.4 290 40 21 8.8 4.8 25.6 78.1 12.4 M M
28000 -32.5 -26.5 285 38 20 8.8 4.8 25.4 77.7 12.4 M M
27000 -30.1 -22.2 280 38 19 7.8 4.3 24.8 76.6 12.0 M M
26000 -27.7 -17.9 275 37 19 7.8 4.3 24.0 75.2 11.5 M M
25000 -25.4 -13.7 275 37 19 7.7 4.3 23.3 74.0 11.1 M M
24000 -23.2 -9.8 270 36 19 6.9 3.8 22.6 72.6 10.6 M M
23000 -21.1 -6.0 270 35 18 7.0 3.8 21.5 70.7 9.8 M M
22000 -19.0 -2.2 265 33 17 7.0 3.9 20.6 69.1 9.1 M M
21000 -16.7 1.9 265 32 17 8.2 4.5 19.9 67.7 8.5 M M
20000 -14.2 6.4 260 31 16 8.3 4.5 19.3 66.8 8.2 M M
19500 -13.0 8.6 260 30 16 8.3 4.5 19.1 66.4 8.0 M M
19000 -11.7 10.9 260 30 15 8.3 4.5 18.9 66.0 7.9 M M
18500 -10.5 13.1 260 29 15 8.0 4.4 18.6 65.5 7.7 M M
18000 -9.3 15.3 260 28 15 8.0 4.4 18.3 65.0 7.5 M M
17500 -8.1 17.4 260 28 14 7.8 4.3 18.1 64.5 7.3 M M
17000 -6.4 20.5 255 27 14 7.7 4.2 17.5 63.6 6.9 M M
16500 -5.2 22.6 255 27 14 7.2 4.0 17.2 62.9 6.6 M M
16000 -4.1 24.6 255 27 14 7.1 3.9 16.7 62.1 6.2 M M
15500 -3.1 26.4 255 27 14 7.1 3.9 16.3 61.4 5.9 M M
15000 -2.0 28.4 260 28 14 7.0 3.8 15.9 60.6 5.5 M M
14500 -1.0 30.2 260 29 15 6.0 3.3 15.5 59.8 5.1 M M
14000 -0.1 31.8 260 29 15 6.4 3.5 14.8 58.6 4.5 M M
13500 0.8 33.4 260 30 16 6.5 3.5 14.2 57.6 4.0 M M
13000 1.7 35.1 260 31 16 5.4 3.0 13.6 56.5 3.4 M M
12500 2.6 36.7 265 30 16 6.1 3.4 13.0 55.5 2.9 M M
12000 3.5 38.3 265 29 15 6.6 3.6 12.5 54.5 2.4 M M
11750 4.1 39.4 260 28 14 6.9 3.8 12.3 54.1 2.2 M M
11500 4.6 40.3 260 26 13 7.6 4.1 12.1 53.7 2.0 M M
11250 5.1 41.2 260 25 13 5.3 2.9 11.9 53.3 1.8 M M
11000 5.3 41.5 260 23 12 1.8 1.0 11.3 52.4 1.2 M M
10750 5.4 41.7 260 22 11 -0.1 -0.1 10.7 51.2 0.6 M M
10500 5.3 41.5 255 20 10 0.5 0.3 9.9 49.8 -0.2 202 1.0
10250 5.2 41.4 255 19 10 -4.7 -2.6 9.1 48.4 -1.0 197 1.0
10000 4.5 40.1 250 18 9 -12.8 -7.0 7.6 45.7 -2.5 213 1.1
9750 3.4 38.1 245 17 9 -14.4 -7.9 5.8 42.5 -4.4 238 1.2
9500 2.3 36.1 245 17 8 -12.3 -6.8 4.1 39.3 -6.2 264 1.3
9250 1.1 34.0 240 16 8 -23.7 -13.0 2.2 35.9 -8.2 292 1.5
9000 -3.3 26.1 230 8 4 -99.0 -54.3 -2.9 26.8 -13.3 416 2.1
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 * * * * * *
11/23/2024 at 0800 MST | 11/23/2024 at 1100 MST
|
CAPE... 0.0 LI... +0.8 | CAPE... 0.0 LI... +1.8
CINH... 0.0 K Index... -24.2 | CINH... 0.0 K Index... -24.6
|
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 -67.8 -90.0 285 58 30 -0.2 -0.1 | -67.5 -89.5 280 63 33 0.2 0.1
45000 -67.7 -89.9 290 69 35 3.0 1.7 | -66.9 -88.4 290 74 38 2.6 1.4
40000 -63.3 -81.9 285 65 34 2.7 1.5 | -63.0 -81.4 285 65 33 2.3 1.2
38000 -58.9 -74.0 285 64 33 8.4 4.6 | -58.3 -72.9 285 64 33 8.9 4.9
36000 -53.8 -64.8 290 62 32 8.4 4.6 | -53.0 -63.4 285 62 32 8.9 4.9
34000 -47.8 -54.0 290 58 30 9.1 5.0 | -47.0 -52.6 285 59 30 8.7 4.8
32000 -42.4 -44.3 285 53 27 9.1 5.0 | -41.7 -43.1 285 53 27 8.7 4.8
30000 -37.0 -34.6 280 44 23 8.8 4.8 | -36.4 -33.5 280 47 24 9.0 4.9
29000 -34.3 -29.7 275 40 20 8.8 4.8 | -33.7 -28.7 280 44 23 9.0 4.9
28000 -31.7 -25.1 270 35 18 8.8 4.8 | -31.0 -23.8 280 40 21 9.0 4.9
27000 -29.2 -20.6 265 35 18 7.9 4.3 | -28.5 -19.3 275 39 20 8.0 4.4
26000 -26.8 -16.2 265 38 19 7.9 4.3 | -26.1 -15.0 270 40 21 8.0 4.4
25000 -24.5 -12.1 265 40 21 7.9 4.3 | -23.7 -10.7 270 41 21 8.0 4.4
24000 -22.3 -8.1 265 41 21 5.6 3.0 | -21.5 -6.7 265 43 22 6.6 3.6
23000 -20.7 -5.3 270 40 21 5.7 3.1 | -19.5 -3.1 265 46 23 6.7 3.7
22000 -19.0 -2.2 270 39 20 5.8 3.2 | -17.5 0.5 265 48 25 6.7 3.7
21000 -16.9 1.6 270 37 19 8.3 4.6 | -15.4 4.3 265 49 25 7.3 4.0
20000 -14.4 6.1 270 36 18 8.4 4.6 | -13.2 8.2 265 48 25 7.3 4.0
19500 -13.1 8.4 265 35 18 8.4 4.6 | -12.1 10.2 265 47 24 7.3 4.0
19000 -11.9 10.6 265 34 18 8.4 4.6 | -11.0 12.2 265 47 24 7.2 4.0
18500 -10.6 12.9 265 34 17 8.8 4.8 | -9.9 14.2 265 47 24 7.6 4.2
18000 -9.2 15.4 265 33 17 8.8 4.8 | -8.8 16.2 265 47 24 7.6 4.2
17500 -7.9 17.8 260 33 17 8.5 4.7 | -7.1 19.2 260 47 24 7.0 3.8
17000 -6.6 20.1 260 33 17 8.4 4.6 | -6.0 21.2 260 46 24 7.1 3.9
16500 -4.8 23.4 260 33 17 7.4 4.1 | -5.0 23.0 260 45 23 7.1 3.9
16000 -3.7 25.3 255 32 17 7.1 3.9 | -3.9 25.0 260 44 23 7.1 3.9
15500 -2.6 27.3 255 32 16 6.9 3.8 | -2.8 27.0 260 43 22 6.9 3.8
15000 -1.6 29.1 255 32 16 6.2 3.4 | -1.9 28.6 260 43 22 5.8 3.2
14500 -0.7 30.7 255 32 16 5.0 2.8 | -1.0 30.2 260 42 22 4.2 2.3
14000 -0.0 32.0 255 32 16 4.8 2.6 | -0.4 31.3 260 42 22 5.0 2.7
13500 0.7 33.3 255 32 16 4.5 2.5 | 0.3 32.5 260 41 21 4.6 2.5
13000 1.4 34.5 260 32 17 5.5 3.0 | 1.0 33.8 260 40 21 4.9 2.7
12500 2.2 36.0 260 32 17 5.3 2.9 | 1.8 35.2 260 37 19 4.8 2.6
12000 2.9 37.2 260 32 16 4.8 2.6 | 2.5 36.5 260 33 17 5.1 2.8
11750 3.3 37.9 260 30 16 5.4 2.9 | 2.9 37.2 260 31 16 5.4 2.9
11500 3.7 38.7 260 29 15 5.7 3.1 | 3.3 37.9 255 28 15 5.6 3.1
11250 4.1 39.4 260 27 14 4.8 2.6 | 3.7 38.7 255 26 14 4.9 2.7
11000 4.4 39.9 255 25 13 3.4 1.9 | 4.0 39.2 250 25 13 2.9 1.6
10750 4.6 40.3 255 24 12 2.0 1.1 | 4.1 39.4 250 23 12 -0.3 -0.1
10500 4.8 40.6 255 22 11 2.8 1.5 | 3.9 39.0 245 22 11 -2.1 -1.1
10250 4.9 40.8 255 20 10 -2.8 -1.5 | 3.8 38.8 245 21 11 -2.4 -1.3
10000 4.2 39.6 250 19 10 -12.4 -6.8 | 3.5 38.3 240 19 10 -4.2 -2.3
9750 3.1 37.6 245 18 9 -14.3 -7.9 | 3.1 37.6 240 18 9 -4.3 -2.3
9500 2.0 35.6 240 17 9 -15.2 -8.3 | 2.9 37.2 235 17 9 -0.4 -0.2
9250 0.5 32.9 235 16 8 -24.6 -13.5 | 3.1 37.6 230 15 8 8.1 4.5
9000 -2.6 27.3 230 8 4 -62.2 -34.2 | 4.2 39.6 225 10 5 24.8 13.6
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
11/23/2024 at 1400 MST | 11/23/2024 at 1700 MST
|
CAPE... 0.0 LI... +2.2 | CAPE... 0.0 LI... +2.7
CINH... 0.0 K Index... -13.4 | CINH... 0.0 K Index... -14.4
|
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 -69.3 -92.7 285 56 29 1.3 0.7 | -70.6 -95.1 270 59 31 2.7 1.5
45000 -67.1 -88.8 285 71 36 3.3 1.8 | -66.4 -87.5 280 64 33 4.1 2.2
40000 -62.0 -79.6 275 54 28 3.0 1.7 | -60.2 -76.4 275 55 28 3.9 2.1
38000 -57.4 -71.3 275 51 26 8.5 4.7 | -56.3 -69.3 265 52 27 7.0 3.9
36000 -52.2 -62.0 270 49 25 8.5 4.7 | -52.1 -61.8 260 49 25 7.0 3.9
34000 -46.3 -51.3 275 48 25 9.2 5.0 | -47.3 -53.1 255 47 24 9.0 4.9
32000 -40.8 -41.4 275 49 25 9.2 5.0 | -41.3 -42.3 255 44 23 9.0 4.9
30000 -35.5 -31.9 275 51 26 8.4 4.6 | -35.9 -32.6 255 44 23 9.0 4.9
29000 -33.0 -27.4 275 52 27 8.4 4.6 | -33.2 -27.8 255 45 23 9.0 4.9
28000 -30.5 -22.9 275 53 27 8.4 4.6 | -30.5 -22.9 260 46 24 9.0 4.9
27000 -28.0 -18.4 275 53 27 8.0 4.4 | -27.9 -18.2 260 48 25 8.0 4.4
26000 -25.6 -14.1 270 53 27 8.0 4.4 | -25.6 -14.1 260 51 26 8.0 4.4
25000 -23.2 -9.8 270 53 27 8.0 4.4 | -23.2 -9.8 255 53 27 8.0 4.4
24000 -20.9 -5.6 265 53 27 7.5 4.1 | -20.8 -5.4 255 55 28 7.9 4.3
23000 -18.7 -1.7 265 53 27 7.5 4.1 | -18.4 -1.1 260 56 29 7.9 4.4
22000 -16.5 2.3 265 53 28 7.6 4.2 | -16.0 3.2 260 56 29 7.9 4.3
21000 -14.2 6.4 260 54 28 7.2 4.0 | -13.7 7.3 260 57 29 7.4 4.1
20000 -12.1 10.2 260 55 28 7.2 4.0 | -11.5 11.3 260 57 29 7.5 4.1
19500 -11.0 12.2 260 55 29 7.2 4.0 | -10.4 13.3 260 56 29 7.5 4.1
19000 -9.9 14.2 260 56 29 7.2 4.0 | -9.3 15.3 260 56 29 7.6 4.2
18500 -8.8 16.2 260 56 29 7.3 4.0 | -8.2 17.2 260 56 29 6.6 3.6
18000 -7.7 18.1 260 56 29 7.3 4.0 | -7.2 19.0 260 57 29 6.5 3.6
17500 -6.6 20.1 260 56 29 7.0 3.8 | -6.3 20.7 260 57 30 6.3 3.5
17000 -5.1 22.8 260 55 29 6.2 3.4 | -4.9 23.2 260 58 30 5.8 3.2
16500 -4.2 24.4 260 55 28 6.0 3.3 | -4.1 24.6 260 59 30 5.6 3.1
16000 -3.3 26.1 260 55 28 5.6 3.1 | -3.3 26.1 260 59 30 5.2 2.9
15500 -2.5 27.5 260 55 28 5.6 3.1 | -2.5 27.5 260 59 30 5.2 2.9
15000 -1.6 29.1 265 54 28 6.2 3.4 | -1.7 28.9 265 59 30 5.4 3.0
14500 -0.7 30.7 265 54 28 4.2 2.3 | -0.9 30.4 265 58 30 3.7 2.0
14000 -0.2 31.6 265 54 28 5.0 2.7 | -0.4 31.3 265 58 30 5.0 2.7
13500 0.6 33.1 265 53 27 5.3 2.9 | 0.4 32.7 265 57 29 5.6 3.1
13000 1.3 34.3 265 52 27 3.0 1.6 | 1.1 34.0 265 56 29 4.0 2.2
12500 1.7 35.1 265 48 25 3.3 1.8 | 1.9 35.4 265 54 28 5.1 2.8
12000 2.3 36.1 265 43 22 4.4 2.4 | 2.7 36.9 265 51 26 4.5 2.5
11750 2.6 36.7 265 40 21 4.2 2.3 | 2.9 37.2 265 46 24 3.9 2.1
11500 2.8 37.0 260 37 19 3.6 2.0 | 3.2 37.8 265 43 22 4.2 2.3
11250 3.1 37.6 260 34 17 4.0 2.2 | 3.5 38.3 260 39 20 4.6 2.5
11000 3.3 37.9 260 31 16 3.1 1.7 | 3.8 38.8 260 35 18 2.8 1.5
10750 3.5 38.3 255 28 14 1.0 0.6 | 3.8 38.8 260 33 17 0.2 0.1
10500 3.5 38.3 255 25 13 0.1 0.1 | 3.8 38.8 255 31 16 -0.2 -0.1
10250 3.5 38.3 250 23 12 0.2 0.1 | 3.8 38.8 255 28 15 0.9 0.5
10000 3.5 38.3 245 20 10 1.6 0.9 | 3.7 38.7 255 26 13 -3.1 -1.7
9750 3.7 38.7 240 19 10 3.3 1.8 | 3.2 37.8 250 24 12 -7.7 -4.2
9500 4.0 39.2 235 17 9 5.3 2.9 | 2.8 37.0 240 22 11 -3.4 -1.9
9250 4.6 40.3 230 15 8 11.1 6.1 | 2.4 36.3 235 19 10 -9.6 -5.3
9000 5.6 42.1 225 10 5 18.4 10.1 | -0.1 31.8 225 9 5 -71.3 -39.1
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