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:

 260911/1200

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 Fri 81 81 N 2 6 2062 2000 0 Blue 26
1 AM Fri 80 80 N 2 6 2005 2000 0 Blue 25
2 AM Fri 78 78 NNE 2 4 1891 2000 0 Blue 23
3 AM Fri 77 77 NNE 1 4 1874 2000 0 Blue 22
4 AM Fri 75 75 NE 1 3 1855 2000 0 Blue 20
5 AM Fri 74 74 NE 1 3 1846 2000 0 Blue 19
6 AM Fri 74 74 ENE 2 4 1846 2000 0 Blue 19
7 AM Fri 73 73 ENE 2 3 1838 2000 0 Blue 18
8 AM Fri 74 74 E 4 6 1846 2000 0 Blue 19
9 AM Fri 79 80 SSW 3 4 2005 2000 0 Blue 25
10 AM Fri 86 89 WSW 4 8 3730 2950 950 Blue 34
11 AM Fri 89 94 W 5 11 4862 4133 2133 Blue 39
12 Noon Fri 90 96 W 6 14 7727 4549 2549 Blue 41
1 PM Fri 91 97 W 8 16 7790 4829 2829 Blue 42
2 PM Fri 92 98 W 8 17 7946 6279 4279 Blue 43
3 PM Fri 92 97 W 8 17 7790 4829 2829 Blue 42
4 PM Fri 92 95 W 8 17 6417 4342 2342 Blue 40
5 PM Fri 93 94 W 8 17 4862 4133 2133 Blue 39
6 PM Fri 91 91 WNW 6 13 4153 3503 1503 Blue 36
7 PM Fri 88 88 NW 3 9 3519 2669 669 Blue 33
8 PM Fri 84 84 NNW 3 8 2467 2060 60 Blue 29
9 PM Fri 80 80 N 3 5 2005 2000 0 Blue 25
10 PM Fri 78 78 NNE 2 4 1891 2000 0 Blue 23
11 PM Fri 77 77 NNE 2 5 1874 2000 0 Blue 22
12 Midnight Sat 75 75 NNE 3 5 1855 2000 0 Blue 20
1 AM Sat 74 74 NNE 2 4 1846 2000 0 Blue 19
2 AM Sat 73 73 NE 2 4 1838 2000 0 Blue 18
3 AM Sat 72 72 NE 1 3 1829 2000 0 Blue 17
4 AM Sat 71 71 NE 1 3 1821 2000 0 Blue 16
5 AM Sat 70 70 NE 2 3 1813 2000 0 Blue 15
6 AM Sat 70 70 NE 2 3 1813 2000 0 Blue 15
7 AM Sat 69 69 NE 2 3 1804 2000 0 Blue 14
8 AM Sat 71 71 WSW 4 8 1821 2000 0 Blue 16
9 AM Sat 75 76 WSW 4 8 1865 2000 0 Blue 21
10 AM Sat 81 84 WSW 4 8 2467 2060 60 Blue 29
11 AM Sat 83 86 W 6 16 2966 2325 325 Blue 31
12 Noon Sat 84 88 W 6 16 3519 2669 669 Blue 33
1 PM Sat 85 90 W 6 16 3941 3228 1228 Blue 35
2 PM Sat 86 91 W 9 18 4153 3503 1503 Blue 36
3 PM Sat 87 91 W 9 18 4153 3503 1503 Blue 36
4 PM Sat 88 90 W 9 18 3941 3228 1228 Blue 35
5 PM Sat 86 87 WNW 10 21 3246 2460 460 Blue 32
6 PM Sat 84 84 WNW 10 21 2467 2060 60 Blue 29
7 PM Sat 80 80 WNW 10 21 2005 2000 0 Blue 25
8 PM Sat 75 75 NW 12 24 1855 2000 0 Blue 20
9 PM Sat 72 72 NW 12 24 1829 2000 0 Blue 17
10 PM Sat 70 70 NW 12 24 1813 2000 0 Blue 15
11 PM Sat 69 69 NNW 11 23 1804 2000 0 Blue 14
12 Midnight Sun 67 67 NNW 11 23 1788 2000 0 Blue 12
1 AM Sun 65 65 NNW 11 23 1771 2000 0 Blue 10
2 AM Sun 64 64 NNW 5 12 1762 2000 0 Blue 9
3 AM Sun 63 63 NNW 5 12 1751 2000 0 Blue 8
4 AM Sun 62 62 NNW 5 12 1739 2000 0 Blue 7
5 AM Sun 61 61 N 2 5 1727 2000 0 Blue 6
6 AM Sun 61 61 N 2 5 1727 2000 0 Blue 6
7 AM Sun 60 60 N 2 5 1716 2000 0 Blue 5
8 AM Sun 61 61 NNW 3 8 1727 2000 0 Blue 6
9 AM Sun 64 65 NNW 3 8 1771 2000 0 Blue 10
10 AM Sun 67 70 NNW 3 8 1813 2000 0 Blue 15
11 AM Sun 71 75 W 6 13 1855 2000 0 Blue 20
12 Noon Sun 74 80 W 6 13 2005 2000 0 Blue 25
1 PM Sun 77 83 W 6 13 2330 2003 3 Blue 28
2 PM Sun 78 84 W 9 20 2467 2060 60 Blue 29
3 PM Sun 80 85 W 9 20 2683 2190 190 Blue 30
4 PM Sun 80 83 W 9 20 2330 2003 3 Blue 28
5 PM Sun 79 80 WNW 10 21 2005 2000 0 Blue 25
6 PM Sun 77 77 WNW 10 21 1874 2000 0 Blue 22
7 PM Sun 75 75 WNW 10 21 1855 2000 0 Blue 20
8 PM Sun 72 72 NNW 6 13 1829 2000 0 Blue 17
9 PM Sun 70 70 NNW 6 13 1813 2000 0 Blue 15
10 PM Sun 69 69 NNW 6 13 1804 2000 0 Blue 14
11 PM Sun 68 68 N 1 4 1796 2000 0 Blue 13
12 Midnight Mon 67 67 N 1 4 1788 2000 0 Blue 12
1 AM Mon 65 65 N 1 4 1771 2000 0 Blue 10
2 AM Mon 64 64 N 0 2 1762 2000 0 Blue 9
3 AM Mon 63 63 N 0 2 1751 2000 0 Blue 8
4 AM Mon 62 62 N 0 2 1739 2000 0 Blue 7
5 AM Mon 61 61 N 0 2 1727 2000 0 Blue 6
6 AM Mon 61 61 N 0 2 1727 2000 0 Blue 6
7 AM Mon 61 61 N 0 2 1727 2000 0 Blue 6
8 AM Mon 63 63 NE 1 3 1751 2000 0 Blue 8
9 AM Mon 67 68 NE 1 3 1796 2000 0 Blue 13
10 AM Mon 72 75 NE 1 3 1855 2000 0 Blue 20
11 AM Mon 76 80 W 4 9 2005 2000 0 Blue 25
12 Noon Mon 79 85 W 4 9 2683 2190 190 Blue 30
1 PM Mon 80 86 W 4 9 2966 2325 325 Blue 31
2 PM Mon 81 87 W 6 13 3246 2460 460 Blue 32
3 PM Mon 83 88 W 6 13 3519 2669 669 Blue 33
4 PM Mon 83 86 W 6 13 2966 2325 325 Blue 31
5 PM Mon 83 84 W 6 13 2467 2060 60 Blue 29
6 PM Mon 80 80 W 6 13 2005 2000 0 Blue 25
7 PM Mon 77 77 W 6 13 1874 2000 0 Blue 22
8 PM Mon 75 75 N 0 3 1855 2000 0 Blue 20
9 PM Mon 73 73 N 0 3 1838 2000 0 Blue 18
10 PM Mon 71 71 N 0 3 1821 2000 0 Blue 16
11 PM Mon 70 70 N 0 2 1813 2000 0 Blue 15
12 Midnight Tue 69 69 N 0 2 1804 2000 0 Blue 14
1 AM Tue 67 67 N 0 2 1788 2000 0 Blue 12
2 AM Tue 66 66 ENE 1 3 1779 2000 0 Blue 11
3 AM Tue 65 65 ENE 1 3 1771 2000 0 Blue 10
4 AM Tue 64 64 ENE 1 3 1762 2000 0 Blue 9
5 AM Tue 63 63 ENE 1 3 1751 2000 0 Blue 8
6 AM Tue 62 62 ENE 1 3 1739 2000 0 Blue 7
7 AM Tue 62 62 ENE 1 3 1739 2000 0 Blue 7
8 AM Tue 64 64 ENE 4 6 1762 2000 0 Blue 9
9 AM Tue 68 69 ENE 4 6 1804 2000 0 Blue 14
10 AM Tue 74 76 ENE 4 6 1865 2000 0 Blue 21
11 AM Tue 79 83 WSW 4 10 2330 2003 3 Blue 28
12 Noon Tue 81 86 WSW 4 10 2966 2325 325 Blue 31
1 PM Tue 83 88 WSW 4 10 3519 2669 669 Blue 33
2 PM Tue 83 88 WSW 6 14 3519 2669 669 Blue 33
3 PM Tue 84 88 WSW 6 14 3519 2669 669 Blue 33
4 PM Tue 85 88 WSW 6 14 3519 2669 669 Blue 33
5 PM Tue 84 85 W 5 12 2683 2190 190 Blue 30
6 PM Tue 82 82 W 5 12 2195 2000 0 Blue 27
7 PM Tue 79 79 W 5 12 1948 2000 0 Blue 24
8 PM Tue 76 76 N 0 3 1865 2000 0 Blue 21
9 PM Tue 74 74 N 0 3 1846 2000 0 Blue 19
10 PM Tue 72 72 N 0 3 1829 2000 0 Blue 17
11 PM Tue 70 70 NE 1 3 1813 2000 0 Blue 15
12 Midnight Wed 68 68 NE 1 3 1796 2000 0 Blue 13
1 AM Wed 67 67 NE 1 3 1788 2000 0 Blue 12
2 AM Wed 66 66 ENE 1 3 1779 2000 0 Blue 11
3 AM Wed 65 65 ENE 1 3 1771 2000 0 Blue 10
4 AM Wed 63 63 ENE 1 3 1751 2000 0 Blue 8
5 AM Wed 63 63 ENE 1 3 1751 2000 0 Blue 8
6 AM Wed 63 63 ENE 1 3 1751 2000 0 Blue 8
7 AM Wed 64 64 ENE 1 3 1762 2000 0 Blue 9
8 AM Wed 66 66 ENE 1 3 1779 2000 0 Blue 11
9 AM Wed 70 71 ENE 1 3 1821 2000 0 Blue 16
10 AM Wed 74 76 ENE 1 3 1865 2000 0 Blue 21
11 AM Wed 78 82 WSW 4 10 2195 2000 0 Blue 27
12 Noon Wed 80 85 WSW 4 10 2683 2190 190 Blue 30
1 PM Wed 82 88 WSW 4 10 3519 2669 669 Blue 33
2 PM Wed 83 88 WSW 5 13 3519 2669 669 Blue 33
3 PM Wed 84 88 WSW 5 13 3519 2669 669 Blue 33
4 PM Wed 84 87 WSW 5 13 3246 2460 460 Blue 32
5 PM Wed 83 84 W 6 12 2467 2060 60 Blue 29
6 PM Wed 81 81 W 6 12 2062 2000 0 Blue 26
7 PM Wed 78 78 W 6 12 1891 2000 0 Blue 23
8 PM Wed 75 75 N 0 3 1855 2000 0 Blue 20
9 PM Wed 73 73 N 0 3 1838 2000 0 Blue 18
10 PM Wed 71 71 N 0 3 1821 2000 0 Blue 16

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]