Detailed Predictions for: Lake McClure
Launch Lat, Long, Altitude (f): 37.3803, -120.0769, 2000
LZ Altitude (f): 500
Sounding

Station:

KOAK

Date/Time:

23 JUN 2021

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Wind
Gust
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
12 Midnight Wed 68 68 NNW 5 12 3729 3671 1671 Blue 13
1 AM Wed 64 64 NNW 6 10 3662 3623 1623 Blue 9
2 AM Wed 63 63 NNW 5 8 3527 3492 1492 White 8
3 AM Wed 64 64 N 4 5 3662 3623 1623 Blue 9
4 AM Wed 63 63 N 3 5 3527 3492 1492 White 8
5 AM Wed 61 61 NNW 9 14 3094 2888 888 White 6
6 AM Wed 60 60 NNW 6 11 2877 2583 583 White 5
7 AM Wed 63 63 NNW 8 12 3527 3492 1492 White 8
8 AM Wed 70 71 WNW 5 9 3833 3726 1726 Blue 16
9 AM Wed 74 77 WNW 6 11 3972 3899 1899 Blue 22
10 AM Wed 76 81 W 6 11 4166 4013 2013 Blue 26
11 AM Wed 79 86 W 8 12 4948 4328 2328 Blue 31
12 Noon Wed 81 89 WSW 9 14 5982 4935 2935 Blue 34
1 PM Wed 83 92 WSW 6 11 7364 5919 3919 Blue 37
2 PM Wed 86 94 SW 8 12 10256 6568 4568 White 39
3 PM Wed 87 94 SW 8 12 10256 6568 4568 White 39
4 PM Wed 88 93 SW 8 12 8014 6246 4246 Blue 38
5 PM Wed 89 92 SW 8 12 7364 5919 3919 Blue 37
6 PM Wed 89 90 WSW 5 9 6294 5054 3054 Blue 35
7 PM Wed 87 87 WSW 5 12 5085 4463 2463 Blue 32
8 PM Wed 83 83 W 6 11 4346 4113 2113 Blue 28
9 PM Wed 77 77 W 5 10 3972 3899 1899 Blue 22
10 PM Wed 73 73 NW 4 8 3878 3801 1801 Blue 18
11 PM Wed 70 70 NW 3 5 3805 3692 1692 Blue 15
12 Midnight Thu 68 68 NW 2 4 3729 3671 1671 Blue 13
1 AM Thu 66 66 NW 2 4 3683 3650 1650 Blue 11
2 AM Thu 64 64 WNW 2 4 3662 3623 1623 Blue 9
3 AM Thu 63 63 NW 2 4 3527 3492 1492 White 8
4 AM Thu 62 62 NNW 3 5 3311 3192 1192 White 7
5 AM Thu 61 61 NNW 3 5 3094 2888 888 White 6
6 AM Thu 61 61 NW 3 5 3094 2888 888 White 6
7 AM Thu 64 64 NW 2 4 3662 3623 1623 Blue 9
8 AM Thu 70 71 WNW 2 4 3833 3726 1726 Blue 16
9 AM Thu 73 76 W 2 4 3946 3876 1876 Blue 21
10 AM Thu 75 80 WSW 3 5 4118 3969 1969 Blue 25
11 AM Thu 77 83 WSW 4 10 4346 4113 2113 Blue 28
12 Noon Thu 80 87 WSW 5 10 5085 4463 2463 Blue 32
1 PM Thu 82 90 WSW 6 10 6294 5054 3054 Blue 35
2 PM Thu 84 91 WSW 8 14 6695 5513 3513 Blue 36
3 PM Thu 86 92 WSW 9 14 7364 5919 3919 Blue 37
4 PM Thu 87 91 WSW 9 14 6695 5513 3513 Blue 36
5 PM Thu 87 90 WSW 9 13 6294 5054 3054 Blue 35
6 PM Thu 87 88 W 8 13 5571 4552 2552 Blue 33
7 PM Thu 85 85 W 6 13 4600 4208 2208 Blue 30
8 PM Thu 83 83 W 5 9 4346 4113 2113 Blue 28
9 PM Thu 80 80 WNW 5 9 4118 3969 1969 Blue 25
10 PM Thu 76 76 NW 4 9 3946 3876 1876 Blue 21
11 PM Thu 73 73 NNW 4 6 3878 3801 1801 Blue 18
12 Midnight Fri 70 70 NNW 4 6 3805 3692 1692 Blue 15
1 AM Fri 68 68 NNW 3 6 3729 3671 1671 Blue 13
2 AM Fri 67 67 NW 3 5 3693 3661 1661 Blue 12
3 AM Fri 65 65 NW 3 5 3672 3640 1640 Blue 10
4 AM Fri 65 65 WNW 2 5 3672 3640 1640 Blue 10
5 AM Fri 65 65 WNW 2 4 3672 3640 1640 Blue 10
6 AM Fri 67 67 WNW 2 4 3693 3661 1661 Blue 12
7 AM Fri 70 70 W 2 4 3805 3692 1692 Blue 15
8 AM Fri 73 74 W 2 4 3901 3831 1831 Blue 19
9 AM Fri 75 78 WSW 2 4 4017 3921 1921 Blue 23
10 AM Fri 78 83 WSW 3 4 4346 4113 2113 Blue 28
11 AM Fri 80 86 SW 3 5 4948 4328 2328 Blue 31
12 Noon Fri 82 90 WSW 4 5 6294 5054 3054 Blue 35
1 PM Fri 85 93 WSW 4 5 8014 6246 4246 Blue 38
2 PM Fri 87 95 W 5 9 10461 7254 5254 White 40
3 PM Fri 89 95 W 6 9 10461 7254 5254 White 40
4 PM Fri 91 96 W 8 9 10664 7793 5793 White 41
5 PM Fri 91 94 W 8 10 10256 6568 4568 White 39
6 PM Fri 90 91 WNW 8 10 6695 5513 3513 Blue 36
7 PM Fri 88 88 WNW 8 10 5571 4552 2552 Blue 33
8 PM Fri 86 86 NW 6 9 4948 4328 2328 Blue 31
9 PM Fri 83 83 NW 6 9 4346 4113 2113 Blue 28
10 PM Fri 80 80 NW 6 9 4118 3969 1969 Blue 25
11 PM Fri 77 77 NNW 5 8 3972 3899 1899 Blue 22
12 Midnight Sat 75 75 NNW 5 8 3923 3854 1854 Blue 20
1 AM Sat 73 73 NNW 5 8 3878 3801 1801 Blue 18
2 AM Sat 72 72 N 4 5 3856 3764 1764 Blue 17
3 AM Sat 70 70 N 4 5 3805 3692 1692 Blue 15
4 AM Sat 69 69 N 4 5 3767 3682 1682 Blue 14
5 AM Sat 69 69 NNE 4 4 3767 3682 1682 Blue 14
6 AM Sat 71 71 NNE 4 4 3833 3726 1726 Blue 16
7 AM Sat 75 75 NNE 4 4 3923 3854 1854 Blue 20
8 AM Sat 79 80 W 3 5 4118 3969 1969 Blue 25
9 AM Sat 82 85 W 3 5 4600 4208 2208 Blue 30
10 AM Sat 85 90 W 3 5 6294 5054 3054 Blue 35
11 AM Sat 87 94 WSW 5 11 10256 6568 4568 White 39
12 Noon Sat 90 98 WSW 5 11 11069 11069 9069 White 43
1 PM Sat 92 101 WSW 5 11 11676 11676 9676 White 46
2 PM Sat 94 102 W 8 16 11878 11878 9878 White 47
3 PM Sat 96 103 W 8 16 12078 12078 10078 White 48
4 PM Sat 98 103 W 8 16 12078 12078 10078 White 48
5 PM Sat 98 101 WNW 9 17 11676 11676 9676 White 46
6 PM Sat 97 98 WNW 9 17 11069 11069 9069 White 43
7 PM Sat 96 96 WNW 9 17 10664 7793 5793 White 41
8 PM Sat 93 93 NW 5 10 8014 6246 4246 Blue 38
9 PM Sat 90 90 NW 5 10 6294 5054 3054 Blue 35
10 PM Sat 86 86 NW 5 10 4948 4328 2328 Blue 31
11 PM Sat 83 83 NNW 4 6 4346 4113 2113 Blue 28
12 Midnight Sun 81 81 NNW 4 6 4166 4013 2013 Blue 26
1 AM Sun 79 79 NNW 4 6 4068 3944 1944 Blue 24
2 AM Sun 77 77 N 3 6 3972 3899 1899 Blue 22
3 AM Sun 75 75 N 3 6 3923 3854 1854 Blue 20
4 AM Sun 74 74 N 3 6 3901 3831 1831 Blue 19
5 AM Sun 74 74 NNE 3 4 3901 3831 1831 Blue 19
6 AM Sun 77 77 NNE 3 4 3972 3899 1899 Blue 22
7 AM Sun 81 81 NNE 3 4 4166 4013 2013 Blue 26
8 AM Sun 85 86 W 3 4 4948 4328 2328 Blue 31
9 AM Sun 88 91 W 3 4 6695 5513 3513 Blue 36
10 AM Sun 91 96 W 3 4 10664 7793 5793 White 41
11 AM Sun 94 101 WSW 5 11 11676 11676 9676 White 46
12 Noon Sun 96 104 WSW 5 11 12276 12276 10276 White 49
1 PM Sun 98 107 WSW 5 11 12869 12869 10869 White 52
2 PM Sun 100 108 W 8 16 13068 13068 11068 White 53
3 PM Sun 102 109 W 8 16 13266 13266 11266 White 54
4 PM Sun 103 108 W 8 16 13068 13068 11068 White 53
5 PM Sun 103 106 WNW 9 16 12672 12672 10672 White 51
6 PM Sun 102 103 WNW 9 16 12078 12078 10078 White 48
7 PM Sun 99 99 WNW 9 16 11272 11272 9272 White 44
8 PM Sun 96 96 NW 6 11 10664 7793 5793 White 41
9 PM Sun 92 92 NW 6 11 7364 5919 3919 Blue 37
10 PM Sun 88 88 NW 6 11 5571 4552 2552 Blue 33
11 PM Sun 84 84 NNW 4 9 4473 4162 2162 Blue 29
12 Midnight Mon 81 81 NNW 4 9 4166 4013 2013 Blue 26
1 AM Mon 79 79 NNW 4 9 4068 3944 1944 Blue 24
2 AM Mon 78 78 N 4 8 4017 3921 1921 Blue 23
3 AM Mon 76 76 N 4 8 3946 3876 1876 Blue 21
4 AM Mon 75 75 N 4 8 3923 3854 1854 Blue 20
5 AM Mon 75 75 N 3 6 3923 3854 1854 Blue 20
6 AM Mon 77 77 N 3 6 3972 3899 1899 Blue 22
7 AM Mon 81 81 N 3 6 4166 4013 2013 Blue 26
8 AM Mon 85 86 WNW 4 6 4948 4328 2328 Blue 31
9 AM Mon 88 91 WNW 4 6 6695 5513 3513 Blue 36
10 AM Mon 91 96 WNW 4 6 10664 7793 5793 White 41
11 AM Mon 93 100 W 6 11 11474 11474 9474 White 45
12 Noon Mon 96 104 W 6 11 12276 12276 10276 White 49
1 PM Mon 98 107 W 6 11 12869 12869 10869 White 52
2 PM Mon 100 108 W 9 18 13068 13068 11068 White 53
3 PM Mon 101 108 W 9 18 13068 13068 11068 White 53
4 PM Mon 102 107 W 9 18 12869 12869 10869 White 52
5 PM Mon 101 104 NW 10 20 12276 12276 10276 White 49
6 PM Mon 99 100 NW 10 20 11474 11474 9474 White 45
7 PM Mon 97 97 NW 10 20 10867 10046 8046 White 42
8 PM Mon 94 94 NW 6 11 10256 6568 4568 White 39
9 PM Mon 91 91 NW 6 11 6695 5513 3513 Blue 36
10 PM Mon 87 87 NW 6 11 5085 4463 2463 Blue 32

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 or WeatherAPI.com website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service or WeatherAPI.com 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 or WeatherAPI.com website.

Wind Gust: This estimate is taken from the National Weather Service or WeatherAPI.com 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 [email protected]