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

Station:

KTUS

Date/Time:

17 SEP 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 69 69 SE 8 3769 4900 0 Blue 0
7 AM Tue 71 71 SE 8 4012 4900 0 Blue 0
8 AM Tue 69 70 SE 8 3890 4900 0 Blue 0
9 AM Tue 74 76 SE 8 5224 4900 0 Blue 1
10 AM Tue 77 80 SE 9 6648 5644 744 Blue 5
11 AM Tue 78 82 S 9 9950 6300 1400 Blue 7
12 Noon Tue 79 84 S 10 11100 6944 2044 Blue 9
1 PM Tue 81 85 S 12 11324 9748 4848 Blue 10
2 PM Tue 82 86 S 13 11658 10827 5927 Blue 11
3 PM Tue 83 86 SW 13 11658 10827 5927 Blue 11
4 PM Tue 84 86 SW 13 11658 10827 5927 Blue 11
5 PM Tue 83 83 SW 13 10874 6623 1723 Blue 8
6 PM Tue 83 83 SW 12 10874 6623 1723 Blue 8
7 PM Tue 81 81 SW 9 6972 5974 1074 Blue 6
8 PM Tue 78 78 W 7 5992 4900 0 Blue 3
9 PM Tue 75 75 W 5 4697 4900 0 Blue 0
10 PM Tue 74 74 W 3 4378 4900 0 Blue 0
11 PM Tue 73 73 NW 3 4256 4900 0 Blue 0
12 Midnight Wed 72 72 NW 3 4134 4900 0 Blue 0
1 AM Wed 71 71 N 3 4012 4900 0 Blue 0
2 AM Wed 71 71 NE 3 4012 4900 0 Blue 0
3 AM Wed 71 71 E 3 4012 4900 0 Blue 0
4 AM Wed 70 70 E 5 3890 4900 0 Blue 0
5 AM Wed 70 70 SE 5 3890 4900 0 Blue 0
6 AM Wed 69 69 SE 6 3769 4900 0 Blue 0
7 AM Wed 68 68 SE 6 3647 4900 0 Blue 0
8 AM Wed 69 69 SE 5 3769 4900 0 Blue 0
9 AM Wed 75 77 SE 5 5660 4900 0 Blue 2
10 AM Wed 79 83 S 7 10874 6623 1723 Blue 8
11 AM Wed 81 86 S 9 11658 10827 5927 Blue 11
12 Noon Wed 82 88 S 12 12612 11273 6373 White 13
1 PM Wed 84 90 S 13 13032 12224 7324 White 15
2 PM Wed 85 90 S 14 13032 12224 7324 White 15
3 PM Wed 85 89 S 14 12822 11575 6675 White 14
4 PM Wed 86 88 S 14 12612 11273 6373 White 13
5 PM Wed 86 87 S 15 12402 11050 6150 White 12
6 PM Wed 84 84 SW 15 11100 6944 2044 Blue 9
7 PM Wed 81 81 SW 13 6972 5974 1074 Blue 6
8 PM Wed 78 78 S 12 5992 4900 0 Blue 3
9 PM Wed 76 76 S 9 5224 4900 0 Blue 1
10 PM Wed 75 75 S 8 4697 4900 0 Blue 0
11 PM Wed 74 74 S 7 4378 4900 0 Blue 0
12 Midnight Thu 74 74 S 6 4378 4900 0 Blue 0
1 AM Thu 73 73 S 6 4256 4900 0 Blue 0
2 AM Thu 72 72 S 6 4134 4900 0 Blue 0
3 AM Thu 71 71 S 7 4012 4900 0 Blue 0
4 AM Thu 70 70 S 7 3890 4900 0 Blue 0
5 AM Thu 69 69 S 8 3769 4900 0 Blue 0
6 AM Thu 69 69 S 9 3769 4900 0 Blue 0
7 AM Thu 70 70 S 10 3890 4900 0 Blue 0
8 AM Thu 71 72 S 12 4134 4900 0 Blue 0
9 AM Thu 73 75 S 13 4697 4900 0 Blue 0
10 AM Thu 75 79 S 14 6322 5207 307 Blue 4
11 AM Thu 77 83 S 14 10874 6623 1723 Blue 8
12 Noon Thu 79 85 S 15 11324 9748 4848 Blue 10
1 PM Thu 80 86 S 16 11658 10827 5927 Blue 11
2 PM Thu 81 87 S 16 12402 11050 6150 White 12
3 PM Thu 82 86 S 17 11658 10827 5927 Blue 11
4 PM Thu 82 84 S 17 11100 6944 2044 Blue 9
5 PM Thu 82 83 SW 17 10874 6623 1723 Blue 8
6 PM Thu 81 81 SW 16 6972 5974 1074 Blue 6
7 PM Thu 79 79 SW 15 6322 5207 307 Blue 4
8 PM Thu 76 76 SW 13 5224 4900 0 Blue 1
9 PM Thu 73 73 SW 12 4256 4900 0 Blue 0
10 PM Thu 71 71 SW 9 4012 4900 0 Blue 0
11 PM Thu 70 70 SW 7 3890 4900 0 Blue 0
12 Midnight Fri 69 69 SW 6 3769 4900 0 Blue 0
1 AM Fri 68 68 SW 6 3647 4900 0 Blue 0
2 AM Fri 67 67 SW 6 3525 4900 0 Blue 0
3 AM Fri 66 66 SW 6 3412 4900 0 Blue 0
4 AM Fri 65 65 S 6 3412 4900 0 Blue 0
5 AM Fri 64 64 S 7 3412 4900 0 Blue 0
6 AM Fri 64 64 S 7 3412 4900 0 Blue 0
7 AM Fri 65 65 S 7 3412 4900 0 Blue 0
8 AM Fri 67 68 S 7 3647 4900 0 Blue 0
9 AM Fri 70 72 S 8 4134 4900 0 Blue 0
10 AM Fri 72 76 S 8 5224 4900 0 Blue 1
11 AM Fri 75 81 S 8 6972 5974 1074 Blue 6
12 Noon Fri 77 83 S 8 10874 6623 1723 Blue 8
1 PM Fri 79 85 S 8 11324 9748 4848 Blue 10
2 PM Fri 80 86 S 8 11658 10827 5927 Blue 11
3 PM Fri 81 85 S 8 11324 9748 4848 Blue 10
4 PM Fri 81 83 S 8 10874 6623 1723 Blue 8
5 PM Fri 81 82 S 8 9950 6300 1400 Blue 7
6 PM Fri 80 80 SW 8 6648 5644 744 Blue 5
7 PM Fri 78 78 SW 7 5992 4900 0 Blue 3
8 PM Fri 75 75 SW 7 4697 4900 0 Blue 0
9 PM Fri 72 72 W 6 4134 4900 0 Blue 0
10 PM Fri 70 70 W 5 3890 4900 0 Blue 0
11 PM Fri 69 69 W 3 3769 4900 0 Blue 0
12 Midnight Sat 68 68 W 3 3647 4900 0 Blue 0
1 AM Sat 67 67 NW 3 3525 4900 0 Blue 0
2 AM Sat 66 66 N 3 3412 4900 0 Blue 0
3 AM Sat 65 65 N 5 3412 4900 0 Blue 0
4 AM Sat 64 64 NE 5 3412 4900 0 Blue 0
5 AM Sat 64 64 NE 6 3412 4900 0 Blue 0
6 AM Sat 64 64 E 6 3412 4900 0 Blue 0
7 AM Sat 66 66 E 6 3412 4900 0 Blue 0
8 AM Sat 68 69 E 6 3769 4900 0 Blue 0
9 AM Sat 71 73 SE 6 4256 4900 0 Blue 0
10 AM Sat 74 78 SE 6 5992 4900 0 Blue 3
11 AM Sat 77 82 S 6 9950 6300 1400 Blue 7
12 Noon Sat 79 85 S 6 11324 9748 4848 Blue 10
1 PM Sat 81 86 S 6 11658 10827 5927 Blue 11
2 PM Sat 82 86 S 6 11658 10827 5927 Blue 11
3 PM Sat 83 85 S 7 11324 9748 4848 Blue 10
4 PM Sat 83 84 SW 7 11100 6944 2044 Blue 9
5 PM Sat 83 83 SW 7 10874 6623 1723 Blue 8
6 PM Sat 82 82 SW 7 9950 6300 1400 Blue 7
7 PM Sat 80 80 SW 7 6648 5644 744 Blue 5
8 PM Sat 77 77 SW 6 5660 4900 0 Blue 2
9 PM Sat 74 74 SW 5 4378 4900 0 Blue 0
10 PM Sat 72 72 W 5 4134 4900 0 Blue 0
11 PM Sat 70 70 W 3 3890 4900 0 Blue 0
12 Midnight Sun 69 69 W 3 3769 4900 0 Blue 0
1 AM Sun 68 68 W 3 3647 4900 0 Blue 0
2 AM Sun 68 68 SW 3 3647 4900 0 Blue 0
3 AM Sun 67 67 S 5 3525 4900 0 Blue 0
4 AM Sun 66 66 SE 5 3412 4900 0 Blue 0
5 AM Sun 65 65 SE 6 3412 4900 0 Blue 0
6 AM Sun 65 65 E 6 3412 4900 0 Blue 0
7 AM Sun 67 67 E 6 3525 4900 0 Blue 0
8 AM Sun 69 69 SE 6 3769 4900 0 Blue 0
9 AM Sun 72 73 SE 6 4256 4900 0 Blue 0
10 AM Sun 75 76 SE 7 5224 4900 0 Blue 1
11 AM Sun 78 80 S 7 6648 5644 744 Blue 5
12 Noon Sun 81 83 S 7 10874 6623 1723 Blue 8
1 PM Sun 83 85 S 8 11324 9748 4848 Blue 10
2 PM Sun 84 86 S 8 11658 10827 5927 Blue 11
3 PM Sun 84 85 S 9 11324 9748 4848 Blue 10
4 PM Sun 84 84 S 9 11100 6944 2044 Blue 9
5 PM Sun 84 84 S 10 11100 6944 2044 Blue 9
6 PM Sun 83 83 SW 10 10874 6623 1723 Blue 8
7 PM Sun 81 81 SW 10 6972 5974 1074 Blue 6
8 PM Sun 78 78 SW 9 5992 4900 0 Blue 3
9 PM Sun 75 75 SW 8 4697 4900 0 Blue 0
10 PM Sun 73 73 SW 7 4256 4900 0 Blue 0
11 PM Sun 72 72 SW 7 4134 4900 0 Blue 0
12 Midnight Mon 71 71 SW 6 4012 4900 0 Blue 0
1 AM Mon 70 70 SW 6 3890 4900 0 Blue 0
2 AM Mon 69 69 SW 6 3769 4900 0 Blue 0
3 AM Mon 68 68 SW 7 3647 4900 0 Blue 0
4 AM Mon 67 67 SW 7 3525 4900 0 Blue 0
5 AM Mon 66 66 SW 8 3412 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