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

Station:

KTUS

Date/Time:

21 JUL 2018

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 Sat 76 76 W 8 4118 4900 0 Blue 0
7 AM Sat 76 76 W 7 4118 4900 0 Blue 0
8 AM Sat 76 76 W 7 4118 4900 0 Blue 0
9 AM Sat 77 78 W 6 4486 4900 0 Blue 0
10 AM Sat 80 82 W 6 6234 5348 448 Blue 4
11 AM Sat 84 87 W 6 7934 6629 1729 Blue 9
12 Noon Sat 88 91 W 6 11096 8060 3160 Blue 13
1 PM Sat 91 94 W 6 12915 10980 6080 White 16
2 PM Sat 94 97 W 7 13537 13537 8637 White 19
3 PM Sat 95 98 W 9 13744 13744 8844 White 20
4 PM Sat 95 97 W 10 13537 13537 8637 White 19
5 PM Sat 94 95 W 10 13122 11502 6602 White 17
6 PM Sat 93 93 W 12 12706 10325 5425 White 15
7 PM Sat 91 91 W 10 11096 8060 3160 Blue 13
8 PM Sat 89 89 W 9 8769 7774 2874 Blue 11
9 PM Sat 86 86 W 8 7790 6425 1525 Blue 8
10 PM Sat 84 84 NW 7 6644 6017 1117 Blue 6
11 PM Sat 83 83 NW 6 6439 5812 912 Blue 5
12 Midnight Sun 81 81 NW 5 6029 4900 0 Blue 3
1 AM Sun 80 80 NW 3 5823 4900 0 Blue 2
2 AM Sun 79 79 NW 3 5386 4900 0 Blue 1
3 AM Sun 78 78 NW 3 4486 4900 0 Blue 0
4 AM Sun 77 77 N 3 4303 4900 0 Blue 0
5 AM Sun 76 76 N 5 4118 4900 0 Blue 0
6 AM Sun 76 76 N 5 4118 4900 0 Blue 0
7 AM Sun 78 78 N 5 4486 4900 0 Blue 0
8 AM Sun 80 81 NW 3 6029 4900 0 Blue 3
9 AM Sun 83 85 NW 3 7646 6221 1321 Blue 7
10 AM Sun 86 89 W 3 8769 7774 2874 Blue 11
11 AM Sun 88 92 W 3 11623 8438 3538 Blue 14
12 Noon Sun 90 95 W 3 13122 11502 6602 White 17
1 PM Sun 92 97 W 5 13537 13537 8637 White 19
2 PM Sun 93 97 W 6 13537 13537 8637 White 19
3 PM Sun 95 98 W 8 13744 13744 8844 White 20
4 PM Sun 96 98 W 9 13744 13744 8844 White 20
5 PM Sun 97 98 W 10 13744 13744 8844 White 20
6 PM Sun 97 97 W 12 13537 13537 8637 White 19
7 PM Sun 94 94 W 12 12915 10980 6080 White 16
8 PM Sun 91 91 W 12 11096 8060 3160 Blue 13
9 PM Sun 88 88 W 12 8078 7276 2376 Blue 10
10 PM Sun 86 86 NW 10 7790 6425 1525 Blue 8
11 PM Sun 84 84 NW 10 6644 6017 1117 Blue 6
12 Midnight Mon 84 84 NW 9 6644 6017 1117 Blue 6
1 AM Mon 83 83 NW 9 6439 5812 912 Blue 5
2 AM Mon 81 81 NW 9 6029 4900 0 Blue 3
3 AM Mon 80 80 N 9 5823 4900 0 Blue 2
4 AM Mon 79 79 N 9 5386 4900 0 Blue 1
5 AM Mon 78 78 N 8 4486 4900 0 Blue 0
6 AM Mon 78 78 N 8 4486 4900 0 Blue 0
7 AM Mon 80 80 N 7 5823 4900 0 Blue 2
8 AM Mon 83 84 NW 6 6644 6017 1117 Blue 6
9 AM Mon 86 89 W 6 8769 7774 2874 Blue 11
10 AM Mon 89 94 W 5 12915 10980 6080 White 16
11 AM Mon 92 98 SW 3 13744 13744 8844 White 20
12 Noon Mon 94 101 S 3 14363 14363 9463 White 23
1 PM Mon 95 102 S 3 14569 14569 9669 White 24
2 PM Mon 96 102 SW 5 14569 14569 9669 White 24
3 PM Mon 97 101 SW 6 14363 14363 9463 White 23
4 PM Mon 99 102 SW 7 14569 14569 9669 White 24
5 PM Mon 100 102 W 8 14569 14569 9669 White 24
6 PM Mon 100 100 W 8 14157 14157 9257 White 22
7 PM Mon 98 98 W 8 13744 13744 8844 White 20
8 PM Mon 94 94 W 8 12915 10980 6080 White 16
9 PM Mon 91 91 W 8 11096 8060 3160 Blue 13
10 PM Mon 89 89 W 8 8769 7774 2874 Blue 11
11 PM Mon 87 87 W 7 7934 6629 1729 Blue 9
12 Midnight Tue 86 86 NW 7 7790 6425 1525 Blue 8
1 AM Tue 85 85 NW 7 7646 6221 1321 Blue 7
2 AM Tue 84 84 NW 6 6644 6017 1117 Blue 6
3 AM Tue 83 83 NW 6 6439 5812 912 Blue 5
4 AM Tue 81 81 N 6 6029 4900 0 Blue 3
5 AM Tue 80 80 N 6 5823 4900 0 Blue 2
6 AM Tue 80 80 N 6 5823 4900 0 Blue 2
7 AM Tue 82 82 N 6 6234 5348 448 Blue 4
8 AM Tue 85 86 NE 6 7790 6425 1525 Blue 8
9 AM Tue 89 92 E 6 11623 8438 3538 Blue 14
10 AM Tue 92 97 SE 6 13537 13537 8637 White 19
11 AM Tue 95 101 SE 6 14363 14363 9463 White 23
12 Noon Tue 97 104 S 6 14980 14980 10080 White 26
1 PM Tue 99 106 S 7 15389 15389 10489 White 28
2 PM Tue 100 106 S 8 15389 15389 10489 White 28
3 PM Tue 101 106 SW 9 15389 15389 10489 White 28
4 PM Tue 102 105 SW 9 15185 15185 10285 White 27
5 PM Tue 103 105 SW 10 15185 15185 10285 White 27
6 PM Tue 102 102 W 10 14569 14569 9669 White 24
7 PM Tue 100 100 W 10 14157 14157 9257 White 22
8 PM Tue 96 96 W 10 13331 13331 8431 White 18
9 PM Tue 93 93 W 9 12706 10325 5425 White 15
10 PM Tue 91 91 W 9 11096 8060 3160 Blue 13
11 PM Tue 89 89 W 8 8769 7774 2874 Blue 11
12 Midnight Wed 88 88 W 7 8078 7276 2376 Blue 10
1 AM Wed 86 86 NW 7 7790 6425 1525 Blue 8
2 AM Wed 84 84 NW 6 6644 6017 1117 Blue 6
3 AM Wed 83 83 NW 6 6439 5812 912 Blue 5
4 AM Wed 81 81 N 5 6029 4900 0 Blue 3
5 AM Wed 80 80 N 5 5823 4900 0 Blue 2
6 AM Wed 80 80 N 5 5823 4900 0 Blue 2
7 AM Wed 82 82 N 5 6234 5348 448 Blue 4
8 AM Wed 84 85 NE 5 7646 6221 1321 Blue 7
9 AM Wed 87 89 E 6 8769 7774 2874 Blue 11
10 AM Wed 90 94 SE 7 12915 10980 6080 White 16
11 AM Wed 93 98 SE 7 13744 13744 8844 White 20
12 Noon Wed 96 101 S 8 14363 14363 9463 White 23
1 PM Wed 98 103 S 9 14775 14775 9875 White 25
2 PM Wed 99 104 S 10 14980 14980 10080 White 26
3 PM Wed 100 104 SW 12 14980 14980 10080 White 26
4 PM Wed 101 104 SW 12 14980 14980 10080 White 26
5 PM Wed 101 102 W 13 14569 14569 9669 White 24
6 PM Wed 100 100 W 13 14157 14157 9257 White 22
7 PM Wed 98 98 W 13 13744 13744 8844 White 20
8 PM Wed 95 95 W 13 13122 11502 6602 White 17
9 PM Wed 92 92 W 13 11623 8438 3538 Blue 14
10 PM Wed 90 90 W 12 10552 7917 3017 Blue 12
11 PM Wed 89 89 W 12 8769 7774 2874 Blue 11
12 Midnight Thu 87 87 W 10 7934 6629 1729 Blue 9
1 AM Thu 86 86 W 9 7790 6425 1525 Blue 8
2 AM Thu 84 84 NW 7 6644 6017 1117 Blue 6
3 AM Thu 82 82 NW 6 6234 5348 448 Blue 4
4 AM Thu 80 80 NW 5 5823 4900 0 Blue 2
5 AM Thu 78 78 NW 3 4486 4900 0 Blue 0
6 AM Thu 78 78 N 2 4486 4900 0 Blue 0
7 AM Thu 79 79 NW 3 5386 4900 0 Blue 1
8 AM Thu 81 82 W 5 6234 5348 448 Blue 4
9 AM Thu 84 86 W 6 7790 6425 1525 Blue 8
10 AM Thu 86 88 SW 7 8078 7276 2376 Blue 10
11 AM Thu 89 92 S 8 11623 8438 3538 Blue 14
12 Noon Thu 91 95 S 10 13122 11502 6602 White 17
1 PM Thu 93 97 S 10 13537 13537 8637 White 19
2 PM Thu 95 98 S 12 13744 13744 8844 White 20
3 PM Thu 97 100 SW 12 14157 14157 9257 White 22
4 PM Thu 98 100 SW 13 14157 14157 9257 White 22
5 PM Thu 99 100 SW 13 14157 14157 9257 White 22
6 PM Thu 98 98 SW 13 13744 13744 8844 White 20
7 PM Thu 96 96 SW 12 13331 13331 8431 White 18
8 PM Thu 93 93 SW 12 12706 10325 5425 White 15
9 PM Thu 90 90 SW 10 10552 7917 3017 Blue 12
10 PM Thu 88 88 SW 9 8078 7276 2376 Blue 10
11 PM Thu 87 87 SW 9 7934 6629 1729 Blue 9
12 Midnight Fri 86 86 SW 8 7790 6425 1525 Blue 8
1 AM Fri 85 85 SW 8 7646 6221 1321 Blue 7
2 AM Fri 83 83 SW 7 6439 5812 912 Blue 5
3 AM Fri 81 81 S 7 6029 4900 0 Blue 3
4 AM Fri 79 79 S 7 5386 4900 0 Blue 1
5 AM Fri 78 78 S 7 4486 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