Detailed Predictions for: Lake McClure
Launch Lat, Long, Altitude (f): 37.712452, -120.2343, 2000
LZ Altitude (f): 500
Sounding

Station:

 KOAK

Date/Time UTC:

 260912/1200

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 Sat 76 76 NE 2 4 2466 2094 94 Blue 19
1 AM Sat 75 75 NE 2 4 2202 2041 41 Blue 18
2 AM Sat 73 73 NE 2 4 2095 2000 0 Blue 16
3 AM Sat 73 73 ENE 1 4 2095 2000 0 Blue 16
4 AM Sat 71 71 ENE 2 3 1989 2000 0 Blue 14
5 AM Sat 71 71 ENE 2 3 1989 2000 0 Blue 14
6 AM Sat 70 70 ENE 2 4 1936 2000 0 Blue 13
7 AM Sat 69 69 ENE 2 4 1908 2000 0 Blue 12
8 AM Sat 71 71 E 3 6 1989 2000 0 Blue 14
9 AM Sat 75 76 S 2 4 2466 2094 94 Blue 19
10 AM Sat 82 85 SW 3 8 3760 3337 1337 Blue 28
11 AM Sat 85 89 WSW 5 11 4180 3835 1835 Blue 32
12 Noon Sat 86 91 WSW 6 13 4326 4115 2115 Blue 34
1 PM Sat 87 93 WSW 6 16 4771 4242 2242 Blue 36
2 PM Sat 88 94 W 8 17 5139 4318 2318 Blue 37
3 PM Sat 89 94 W 8 17 5139 4318 2318 Blue 37
4 PM Sat 90 93 W 8 18 4771 4242 2242 Blue 36
5 PM Sat 88 89 W 9 18 4180 3835 1835 Blue 32
6 PM Sat 86 86 WNW 9 19 3842 3516 1516 Blue 29
7 PM Sat 84 84 NW 10 20 3678 3158 1158 Blue 27
8 PM Sat 77 77 NW 10 20 2614 2147 147 Blue 20
9 PM Sat 75 75 NNW 11 21 2202 2041 41 Blue 18
10 PM Sat 73 73 NW 11 23 2095 2000 0 Blue 16
11 PM Sat 71 71 NNW 11 24 1989 2000 0 Blue 14
12 Midnight Sun 69 69 NNW 9 20 1908 2000 0 Blue 12
1 AM Sun 68 68 NW 5 14 1890 2000 0 Blue 11
2 AM Sun 66 66 NNW 2 10 1853 2000 0 Blue 9
3 AM Sun 64 64 NNW 1 8 1812 2000 0 Blue 7
4 AM Sun 62 62 NNW 1 5 1765 2000 0 Blue 5
5 AM Sun 62 62 NNW 2 6 1765 2000 0 Blue 5
6 AM Sun 61 61 NNW 2 6 1735 2000 0 Blue 4
7 AM Sun 60 60 NNW 2 6 1668 2000 0 Blue 3
8 AM Sun 62 62 WNW 5 11 1765 2000 0 Blue 5
9 AM Sun 64 65 WNW 5 11 1835 2000 0 Blue 8
10 AM Sun 69 72 WNW 5 11 2042 2000 0 Blue 15
11 AM Sun 72 77 W 8 18 2614 2147 147 Blue 20
12 Noon Sun 75 81 W 8 18 3170 2738 738 Blue 24
1 PM Sun 77 83 W 8 18 3529 2999 999 Blue 26
2 PM Sun 79 85 W 9 20 3760 3337 1337 Blue 28
3 PM Sun 79 84 W 9 20 3678 3158 1158 Blue 27
4 PM Sun 80 83 W 9 20 3529 2999 999 Blue 26
5 PM Sun 81 82 NW 9 19 3350 2868 868 Blue 25
6 PM Sun 79 79 NW 9 19 2876 2458 458 Blue 22
7 PM Sun 77 77 NW 9 19 2614 2147 147 Blue 20
8 PM Sun 74 74 NNW 6 13 2148 2000 0 Blue 17
9 PM Sun 72 72 NNW 6 13 2042 2000 0 Blue 15
10 PM Sun 70 70 NNW 6 13 1936 2000 0 Blue 13
11 PM Sun 68 68 N 1 5 1890 2000 0 Blue 11
12 Midnight Mon 66 66 N 1 5 1853 2000 0 Blue 9
1 AM Mon 65 65 N 1 5 1835 2000 0 Blue 8
2 AM Mon 64 64 N 0 2 1812 2000 0 Blue 7
3 AM Mon 63 63 N 0 2 1788 2000 0 Blue 6
4 AM Mon 62 62 N 0 2 1765 2000 0 Blue 5
5 AM Mon 61 61 N 0 2 1735 2000 0 Blue 4
6 AM Mon 61 61 N 0 2 1735 2000 0 Blue 4
7 AM Mon 62 62 N 0 2 1765 2000 0 Blue 5
8 AM Mon 63 63 ENE 2 3 1788 2000 0 Blue 6
9 AM Mon 67 68 ENE 2 3 1890 2000 0 Blue 11
10 AM Mon 72 75 ENE 2 3 2202 2041 41 Blue 18
11 AM Mon 76 81 WSW 4 8 3170 2738 738 Blue 24
12 Noon Mon 79 85 WSW 4 8 3760 3337 1337 Blue 28
1 PM Mon 81 87 WSW 4 8 3980 3671 1671 Blue 30
2 PM Mon 82 88 W 6 13 4121 3753 1753 Blue 31
3 PM Mon 84 89 W 6 13 4180 3835 1835 Blue 32
4 PM Mon 84 87 W 6 13 3980 3671 1671 Blue 30
5 PM Mon 84 85 WNW 6 13 3760 3337 1337 Blue 28
6 PM Mon 81 81 WNW 6 13 3170 2738 738 Blue 24
7 PM Mon 78 78 WNW 6 13 2745 2200 200 Blue 21
8 PM Mon 75 75 N 0 3 2202 2041 41 Blue 18
9 PM Mon 73 73 N 0 3 2095 2000 0 Blue 16
10 PM Mon 71 71 N 0 3 1989 2000 0 Blue 14
11 PM Mon 70 70 N 0 3 1936 2000 0 Blue 13
12 Midnight Tue 69 69 N 0 3 1908 2000 0 Blue 12
1 AM Tue 67 67 N 0 3 1871 2000 0 Blue 10
2 AM Tue 66 66 ENE 1 4 1853 2000 0 Blue 9
3 AM Tue 65 65 ENE 1 4 1835 2000 0 Blue 8
4 AM Tue 64 64 ENE 1 4 1812 2000 0 Blue 7
5 AM Tue 63 63 ENE 1 3 1788 2000 0 Blue 6
6 AM Tue 63 63 ENE 1 3 1788 2000 0 Blue 6
7 AM Tue 63 63 ENE 1 3 1788 2000 0 Blue 6
8 AM Tue 65 65 ENE 4 6 1835 2000 0 Blue 8
9 AM Tue 70 71 ENE 4 6 1989 2000 0 Blue 14
10 AM Tue 76 79 ENE 4 6 2876 2458 458 Blue 22
11 AM Tue 81 86 SW 4 9 3842 3516 1516 Blue 29
12 Noon Tue 83 89 SW 4 9 4180 3835 1835 Blue 32
1 PM Tue 84 90 SW 4 9 4250 3964 1964 Blue 33
2 PM Tue 85 91 WSW 6 14 4326 4115 2115 Blue 34
3 PM Tue 86 91 WSW 6 14 4326 4115 2115 Blue 34
4 PM Tue 86 89 WSW 6 14 4180 3835 1835 Blue 32
5 PM Tue 85 86 W 5 12 3842 3516 1516 Blue 29
6 PM Tue 82 82 W 5 12 3350 2868 868 Blue 25
7 PM Tue 79 79 W 5 12 2876 2458 458 Blue 22
8 PM Tue 77 77 N 0 2 2614 2147 147 Blue 20
9 PM Tue 75 75 N 0 2 2202 2041 41 Blue 18
10 PM Tue 73 73 N 0 2 2095 2000 0 Blue 16
11 PM Tue 71 71 ENE 2 3 1989 2000 0 Blue 14
12 Midnight Wed 69 69 ENE 2 3 1908 2000 0 Blue 12
1 AM Wed 68 68 ENE 2 3 1890 2000 0 Blue 11
2 AM Wed 67 67 ENE 1 4 1871 2000 0 Blue 10
3 AM Wed 66 66 ENE 1 4 1853 2000 0 Blue 9
4 AM Wed 65 65 ENE 1 4 1835 2000 0 Blue 8
5 AM Wed 65 65 ENE 2 3 1835 2000 0 Blue 8
6 AM Wed 64 64 ENE 2 3 1812 2000 0 Blue 7
7 AM Wed 64 64 ENE 2 3 1812 2000 0 Blue 7
8 AM Wed 66 66 ENE 4 6 1853 2000 0 Blue 9
9 AM Wed 70 71 ENE 4 6 1989 2000 0 Blue 14
10 AM Wed 75 78 ENE 4 6 2745 2200 200 Blue 21
11 AM Wed 80 84 SW 4 9 3678 3158 1158 Blue 27
12 Noon Wed 82 88 SW 4 9 4121 3753 1753 Blue 31
1 PM Wed 83 89 SW 4 9 4180 3835 1835 Blue 32
2 PM Wed 84 90 WSW 5 13 4250 3964 1964 Blue 33
3 PM Wed 85 90 WSW 5 13 4250 3964 1964 Blue 33
4 PM Wed 86 89 WSW 5 13 4180 3835 1835 Blue 32
5 PM Wed 85 86 WSW 6 12 3842 3516 1516 Blue 29
6 PM Wed 83 83 WSW 6 12 3529 2999 999 Blue 26
7 PM Wed 80 80 WSW 6 12 3007 2608 608 Blue 23
8 PM Wed 77 77 N 0 3 2614 2147 147 Blue 20
9 PM Wed 75 75 N 0 3 2202 2041 41 Blue 18
10 PM Wed 73 73 N 0 3 2095 2000 0 Blue 16
11 PM Wed 72 72 NE 1 4 2042 2000 0 Blue 15
12 Midnight Thu 70 70 NE 1 4 1936 2000 0 Blue 13
1 AM Thu 69 69 NE 1 4 1908 2000 0 Blue 12
2 AM Thu 68 68 NE 1 4 1890 2000 0 Blue 11
3 AM Thu 67 67 NE 1 4 1871 2000 0 Blue 10
4 AM Thu 66 66 NE 1 4 1853 2000 0 Blue 9
5 AM Thu 66 66 ENE 1 3 1853 2000 0 Blue 9
6 AM Thu 66 66 ENE 1 3 1853 2000 0 Blue 9
7 AM Thu 66 66 ENE 1 3 1853 2000 0 Blue 9
8 AM Thu 68 68 NNE 2 4 1890 2000 0 Blue 11
9 AM Thu 72 73 NNE 2 4 2095 2000 0 Blue 16
10 AM Thu 77 80 NNE 2 4 3007 2608 608 Blue 23
11 AM Thu 82 86 WSW 4 9 3842 3516 1516 Blue 29
12 Noon Thu 84 89 WSW 4 9 4180 3835 1835 Blue 32
1 PM Thu 85 91 WSW 4 9 4326 4115 2115 Blue 34
2 PM Thu 86 92 W 6 13 4416 4174 2174 Blue 35
3 PM Thu 87 91 W 6 13 4326 4115 2115 Blue 34
4 PM Thu 88 91 W 6 13 4326 4115 2115 Blue 34
5 PM Thu 87 88 W 6 14 4121 3753 1753 Blue 31
6 PM Thu 85 85 W 6 14 3760 3337 1337 Blue 28
7 PM Thu 81 81 W 6 14 3170 2738 738 Blue 24
8 PM Thu 78 78 NNW 2 4 2745 2200 200 Blue 21
9 PM Thu 76 76 NNW 2 4 2466 2094 94 Blue 19
10 PM Thu 74 74 NNW 2 4 2148 2000 0 Blue 17

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]