Detailed Predictions for: The Y
Launch Altitude (f): 4900
LZ Altitude (f): 3150
Sounding

Station:

KTUS

Date/Time:

20 AUG 2019

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
6 AM Tue 76 76 N 7 3442 4900 0 Blue 0
7 AM Tue 76 76 N 7 3442 4900 0 Blue 0
8 AM Tue 80 81 NW 7 3442 4900 0 Blue 0
9 AM Tue 83 86 NW 7 4135 4900 0 Blue 0
10 AM Tue 87 92 W 7 8735 6150 1250 Blue 5
11 AM Tue 91 98 SW 7 16417 13852 8952 Blue 11
12 Noon Tue 94 102 SW 7 18385 16532 11632 Blue 15
1 PM Tue 96 104 SW 8 18591 18010 13110 Blue 17
2 PM Tue 97 104 SW 8 18591 18010 13110 Blue 17
3 PM Tue 98 104 SW 9 18591 18010 13110 Blue 17
4 PM Tue 99 103 SW 9 18494 16884 11984 Blue 16
5 PM Tue 100 102 SW 10 18385 16532 11632 Blue 15
6 PM Tue 100 100 W 10 17359 15923 11023 Blue 13
7 PM Tue 99 99 W 10 16675 15262 10362 Blue 12
8 PM Tue 98 98 W 9 16417 13852 8952 Blue 11
9 PM Tue 96 96 W 9 15630 10112 5212 Blue 9
10 PM Tue 93 93 NW 8 10381 6918 2018 Blue 6
11 PM Tue 89 89 NW 8 6196 4900 0 Blue 2
12 Midnight Wed 87 87 N 7 4454 4900 0 Blue 0
1 AM Wed 85 85 N 7 3813 4900 0 Blue 0
2 AM Wed 84 84 N 6 3489 4900 0 Blue 0
3 AM Wed 82 82 N 6 3442 4900 0 Blue 0
4 AM Wed 80 80 N 6 3442 4900 0 Blue 0
5 AM Wed 78 78 NE 6 3442 4900 0 Blue 0
6 AM Wed 78 78 NE 6 3442 4900 0 Blue 0
7 AM Wed 80 80 NE 6 3442 4900 0 Blue 0
8 AM Wed 84 85 E 7 3813 4900 0 Blue 0
9 AM Wed 87 90 E 8 6998 4900 0 Blue 3
10 AM Wed 90 95 SE 9 14337 8624 3724 Blue 8
11 AM Wed 92 99 S 10 16675 15262 10362 Blue 12
12 Noon Wed 93 101 S 12 18222 16339 11439 Blue 14
1 PM Wed 95 103 S 13 18494 16884 11984 Blue 16
2 PM Wed 97 104 SW 13 18591 18010 13110 Blue 17
3 PM Wed 99 104 SW 14 18591 18010 13110 Blue 17
4 PM Wed 100 103 SW 14 18494 16884 11984 Blue 16
5 PM Wed 101 103 SW 14 18494 16884 11984 Blue 16
6 PM Wed 101 101 SW 13 18222 16339 11439 Blue 14
7 PM Wed 100 100 W 13 17359 15923 11023 Blue 13
8 PM Wed 98 98 W 10 16417 13852 8952 Blue 11
9 PM Wed 95 95 W 9 14337 8624 3724 Blue 8
10 PM Wed 93 93 W 7 10381 6918 2018 Blue 6
11 PM Wed 91 91 W 6 7903 5388 488 Blue 4
12 Midnight Thu 89 89 NW 5 6196 4900 0 Blue 2
1 AM Thu 87 87 W 5 4454 4900 0 Blue 0
2 AM Thu 85 85 W 5 3813 4900 0 Blue 0
3 AM Thu 83 83 SW 5 3442 4900 0 Blue 0
4 AM Thu 82 82 S 6 3442 4900 0 Blue 0
5 AM Thu 81 81 S 6 3442 4900 0 Blue 0
6 AM Thu 79 79 SE 7 3442 4900 0 Blue 0
7 AM Thu 77 77 S 8 3442 4900 0 Blue 0
8 AM Thu 75 76 S 8 3442 4900 0 Blue 0
9 AM Thu 75 78 S 9 3442 4900 0 Blue 0
10 AM Thu 77 82 S 10 3442 4900 0 Blue 0
11 AM Thu 81 88 S 12 5418 4900 0 Blue 1
12 Noon Thu 84 92 S 12 8735 6150 1250 Blue 5
1 PM Thu 88 96 S 12 15630 10112 5212 Blue 9
2 PM Thu 90 97 S 13 16106 11441 6541 Blue 10
3 PM Thu 92 97 S 13 16106 11441 6541 Blue 10
4 PM Thu 94 97 S 13 16106 11441 6541 Blue 10
5 PM Thu 96 97 SW 13 16106 11441 6541 Blue 10
6 PM Thu 97 97 SW 12 16106 11441 6541 Blue 10
7 PM Thu 97 97 SW 12 16106 11441 6541 Blue 10
8 PM Thu 96 96 SW 12 15630 10112 5212 Blue 9
9 PM Thu 94 94 SW 12 12942 7806 2906 Blue 7
10 PM Thu 92 92 S 12 8735 6150 1250 Blue 5
11 PM Thu 90 90 S 10 6998 4900 0 Blue 3
12 Midnight Fri 87 87 S 10 4454 4900 0 Blue 0
1 AM Fri 84 84 S 9 3489 4900 0 Blue 0
2 AM Fri 81 81 S 8 3442 4900 0 Blue 0
3 AM Fri 79 79 S 7 3442 4900 0 Blue 0
4 AM Fri 77 77 SE 6 3442 4900 0 Blue 0
5 AM Fri 76 76 SE 6 3442 4900 0 Blue 0
6 AM Fri 77 77 SE 5 3442 4900 0 Blue 0
7 AM Fri 79 79 SE 5 3442 4900 0 Blue 0
8 AM Fri 81 82 SE 6 3442 4900 0 Blue 0
9 AM Fri 83 85 S 7 3813 4900 0 Blue 0
10 AM Fri 83 87 S 7 4454 4900 0 Blue 0
11 AM Fri 82 88 S 8 5418 4900 0 Blue 1
12 Noon Fri 83 90 S 9 6998 4900 0 Blue 3
1 PM Fri 86 93 S 10 10381 6918 2018 Blue 6
2 PM Fri 90 96 S 12 15630 10112 5212 Blue 9
3 PM Fri 93 97 S 12 16106 11441 6541 Blue 10
4 PM Fri 92 95 S 13 14337 8624 3724 Blue 8
5 PM Fri 89 90 S 13 6998 4900 0 Blue 3
6 PM Fri 87 87 S 13 4454 4900 0 Blue 0
7 PM Fri 86 86 SW 12 4135 4900 0 Blue 0
8 PM Fri 86 86 SW 9 4135 4900 0 Blue 0
9 PM Fri 86 86 SW 7 4135 4900 0 Blue 0
10 PM Fri 84 84 W 6 3489 4900 0 Blue 0
11 PM Fri 82 82 W 3 3442 4900 0 Blue 0
12 Midnight Sat 80 80 W 2 3442 4900 0 Blue 0
1 AM Sat 79 79 W 2 3442 4900 0 Blue 0
2 AM Sat 79 79 SW 2 3442 4900 0 Blue 0
3 AM Sat 78 78 S 2 3442 4900 0 Blue 0
4 AM Sat 77 77 S 3 3442 4900 0 Blue 0
5 AM Sat 75 75 SE 3 3442 4900 0 Blue 0
6 AM Sat 75 75 SE 5 3442 4900 0 Blue 0
7 AM Sat 77 77 SE 5 3442 4900 0 Blue 0
8 AM Sat 79 80 S 6 3442 4900 0 Blue 0
9 AM Sat 80 82 S 6 3442 4900 0 Blue 0
10 AM Sat 80 84 S 6 3489 4900 0 Blue 0
11 AM Sat 79 85 SW 7 3813 4900 0 Blue 0
12 Noon Sat 80 86 SW 7 4135 4900 0 Blue 0
1 PM Sat 84 91 SW 8 7903 5388 488 Blue 4
2 PM Sat 89 95 SW 10 14337 8624 3724 Blue 8
3 PM Sat 92 96 SW 12 15630 10112 5212 Blue 9
4 PM Sat 91 94 W 13 12942 7806 2906 Blue 7
5 PM Sat 88 89 W 14 6196 4900 0 Blue 2
6 PM Sat 86 86 W 14 4135 4900 0 Blue 0
7 PM Sat 86 86 W 13 4135 4900 0 Blue 0
8 PM Sat 86 86 W 12 4135 4900 0 Blue 0
9 PM Sat 86 86 SW 10 4135 4900 0 Blue 0
10 PM Sat 83 83 SW 8 3442 4900 0 Blue 0
11 PM Sat 80 80 SW 6 3442 4900 0 Blue 0
12 Midnight Sun 77 77 SW 5 3442 4900 0 Blue 0
1 AM Sun 77 77 SW 3 3442 4900 0 Blue 0
2 AM Sun 78 78 SW 3 3442 4900 0 Blue 0
3 AM Sun 79 79 SW 3 3442 4900 0 Blue 0
4 AM Sun 78 78 SW 3 3442 4900 0 Blue 0
5 AM Sun 76 76 W 3 3442 4900 0 Blue 0
6 AM Sun 75 75 W 3 3442 4900 0 Blue 0
7 AM Sun 77 77 W 3 3442 4900 0 Blue 0
8 AM Sun 80 81 W 5 3442 4900 0 Blue 0
9 AM Sun 82 84 W 6 3489 4900 0 Blue 0
10 AM Sun 82 86 W 6 4135 4900 0 Blue 0
11 AM Sun 81 86 W 7 4135 4900 0 Blue 0
12 Noon Sun 82 87 W 8 4454 4900 0 Blue 0
1 PM Sun 85 90 W 9 6998 4900 0 Blue 3
2 PM Sun 89 93 W 10 10381 6918 2018 Blue 6
3 PM Sun 92 95 W 12 14337 8624 3724 Blue 8
4 PM Sun 92 94 W 13 12942 7806 2906 Blue 7
5 PM Sun 90 90 W 13 6998 4900 0 Blue 3
6 PM Sun 88 88 W 13 5418 4900 0 Blue 1
7 PM Sun 87 87 W 13 4454 4900 0 Blue 0
8 PM Sun 87 87 W 13 4454 4900 0 Blue 0
9 PM Sun 86 86 W 12 4135 4900 0 Blue 0
10 PM Sun 84 84 W 10 3489 4900 0 Blue 0
11 PM Sun 82 82 W 10 3442 4900 0 Blue 0
12 Midnight Mon 81 81 NW 9 3442 4900 0 Blue 0
1 AM Mon 81 81 NW 8 3442 4900 0 Blue 0
2 AM Mon 81 81 NW 8 3442 4900 0 Blue 0
3 AM Mon 80 80 NW 7 3442 4900 0 Blue 0
4 AM Mon 78 78 NW 7 3442 4900 0 Blue 0
5 AM Mon 76 76 NW 7 3442 4900 0 Blue 0

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse ac_soaring@yahoo.com