Detailed Predictions for: Mt Tamalpais
Launch Lat, Long, Altitude (f): 37.90719, -122.62, 2040
LZ Altitude (f): 0
Sounding

Station:

 KOAK

Date/Time UTC:

 260615/1200

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 Mon 58 58 WSW 3 5 1819 2040 0 Blue 4
1 AM Mon 58 58 WSW 3 5 1819 2040 0 Blue 4
2 AM Mon 58 58 W 3 5 1819 2040 0 Blue 4
3 AM Mon 58 58 W 2 5 1819 2040 0 Blue 4
4 AM Mon 58 58 W 2 5 1819 2040 0 Blue 4
5 AM Mon 58 58 W 2 5 1819 2040 0 Blue 4
6 AM Mon 56 56 W 2 5 1677 2040 0 White 2
7 AM Mon 57 57 W 3 5 1811 2040 0 Blue 3
8 AM Mon 57 57 W 3 6 1811 2040 0 Blue 3
9 AM Mon 57 59 WSW 4 8 1826 2040 0 Blue 5
10 AM Mon 58 61 WSW 4 9 1838 2040 0 Blue 7
11 AM Mon 58 63 WSW 5 10 1851 2040 0 Blue 9
12 Noon Mon 60 66 W 5 11 1869 2040 0 Blue 12
1 PM Mon 61 68 W 5 11 1886 2040 0 Blue 14
2 PM Mon 62 69 W 6 12 1895 2040 0 Blue 15
3 PM Mon 62 68 W 6 12 1886 2040 0 Blue 14
4 PM Mon 62 67 W 6 11 1877 2040 0 Blue 13
5 PM Mon 63 66 W 6 11 1869 2040 0 Blue 12
6 PM Mon 63 64 W 5 10 1857 2040 0 Blue 10
7 PM Mon 62 62 W 5 10 1844 2040 0 Blue 8
8 PM Mon 61 61 W 5 9 1838 2040 0 Blue 7
9 PM Mon 59 59 W 5 9 1826 2040 0 Blue 5
10 PM Mon 59 59 W 5 9 1826 2040 0 Blue 5
11 PM Mon 58 58 W 4 9 1819 2040 0 Blue 4
12 Midnight Tue 58 58 W 4 8 1819 2040 0 Blue 4
1 AM Tue 59 59 W 4 8 1826 2040 0 Blue 5
2 AM Tue 58 58 W 4 8 1819 2040 0 Blue 4
3 AM Tue 58 58 W 4 8 1819 2040 0 Blue 4
4 AM Tue 58 58 W 3 6 1819 2040 0 Blue 4
5 AM Tue 57 57 W 3 6 1811 2040 0 Blue 3
6 AM Tue 58 58 W 3 6 1819 2040 0 Blue 4
7 AM Tue 58 58 W 3 6 1819 2040 0 Blue 4
8 AM Tue 58 58 SW 4 10 1819 2040 0 Blue 4
9 AM Tue 58 59 SW 4 10 1826 2040 0 Blue 5
10 AM Tue 58 60 SW 4 10 1832 2040 0 Blue 6
11 AM Tue 58 62 SW 5 11 1844 2040 0 Blue 8
12 Noon Tue 60 65 SW 5 11 1863 2040 0 Blue 11
1 PM Tue 61 66 SW 5 11 1869 2040 0 Blue 12
2 PM Tue 62 67 SW 6 11 1877 2040 0 Blue 13
3 PM Tue 62 66 SW 6 11 1869 2040 0 Blue 12
4 PM Tue 63 66 SW 6 11 1869 2040 0 Blue 12
5 PM Tue 62 64 WSW 5 11 1857 2040 0 Blue 10
6 PM Tue 62 63 WSW 5 11 1851 2040 0 Blue 9
7 PM Tue 61 61 WSW 5 11 1838 2040 0 Blue 7
8 PM Tue 60 60 SW 5 9 1832 2040 0 Blue 6
9 PM Tue 59 59 SW 5 9 1826 2040 0 Blue 5
10 PM Tue 60 60 SW 5 9 1832 2040 0 Blue 6
11 PM Tue 60 60 SW 5 9 1832 2040 0 Blue 6
12 Midnight Wed 60 60 SW 5 9 1832 2040 0 Blue 6
1 AM Wed 60 60 SW 5 9 1832 2040 0 Blue 6
2 AM Wed 60 60 SW 5 10 1832 2040 0 Blue 6
3 AM Wed 60 60 SW 5 10 1832 2040 0 Blue 6
4 AM Wed 60 60 SW 5 10 1832 2040 0 Blue 6
5 AM Wed 61 61 SSW 5 9 1838 2040 0 Blue 7
6 AM Wed 61 61 SSW 5 9 1838 2040 0 Blue 7
7 AM Wed 60 60 SSW 5 9 1832 2040 0 Blue 6
8 AM Wed 60 60 SSW 6 12 1832 2040 0 Blue 6
9 AM Wed 59 60 SSW 6 12 1832 2040 0 Blue 6
10 AM Wed 58 59 SSW 6 12 1826 2040 0 Blue 5
11 AM Wed 58 62 SSW 9 17 1844 2040 0 Blue 8
12 Noon Wed 58 62 SSW 9 17 1844 2040 0 Blue 8
1 PM Wed 59 64 SSW 9 17 1857 2040 0 Blue 10
2 PM Wed 60 65 SW 9 16 1863 2040 0 Blue 11
3 PM Wed 60 65 SW 9 16 1863 2040 0 Blue 11
4 PM Wed 60 63 SW 9 16 1851 2040 0 Blue 9
5 PM Wed 60 62 SW 8 13 1844 2040 0 Blue 8
6 PM Wed 59 60 SW 8 13 1832 2040 0 Blue 6
7 PM Wed 59 59 SW 8 13 1826 2040 0 Blue 5
8 PM Wed 58 58 SW 6 11 1819 2040 0 Blue 4
9 PM Wed 59 59 SW 6 11 1826 2040 0 Blue 5
10 PM Wed 59 59 SW 6 11 1826 2040 0 Blue 5
11 PM Wed 60 60 SW 6 11 1832 2040 0 Blue 6
12 Midnight Thu 60 60 SW 6 11 1832 2040 0 Blue 6
1 AM Thu 60 60 SW 6 11 1832 2040 0 Blue 6
2 AM Thu 60 60 SW 6 11 1832 2040 0 Blue 6
3 AM Thu 60 60 SW 6 11 1832 2040 0 Blue 6
4 AM Thu 61 61 SW 6 11 1838 2040 0 Blue 7
5 AM Thu 61 61 SSW 5 10 1838 2040 0 Blue 7
6 AM Thu 61 61 SSW 5 10 1838 2040 0 Blue 7
7 AM Thu 60 60 SSW 5 10 1832 2040 0 Blue 6
8 AM Thu 59 59 SSW 8 13 1826 2040 0 Blue 5
9 AM Thu 58 58 SSW 8 13 1819 2040 0 Blue 4
10 AM Thu 57 58 SSW 8 13 1819 2040 0 Blue 4
11 AM Thu 57 60 SSW 9 16 1832 2040 0 Blue 6
12 Noon Thu 57 61 SSW 9 16 1838 2040 0 Blue 7
1 PM Thu 58 62 SSW 9 16 1844 2040 0 Blue 8
2 PM Thu 58 63 SW 9 17 1851 2040 0 Blue 9
3 PM Thu 59 63 SW 9 17 1851 2040 0 Blue 9
4 PM Thu 59 62 SW 9 17 1844 2040 0 Blue 8
5 PM Thu 58 60 SW 9 13 1832 2040 0 Blue 6
6 PM Thu 58 59 SW 9 13 1826 2040 0 Blue 5
7 PM Thu 58 58 SW 9 13 1819 2040 0 Blue 4
8 PM Thu 58 58 SW 6 12 1819 2040 0 Blue 4
9 PM Thu 59 59 SW 6 12 1826 2040 0 Blue 5
10 PM Thu 60 60 SW 6 12 1832 2040 0 Blue 6
11 PM Thu 60 60 SW 8 12 1832 2040 0 Blue 6
12 Midnight Fri 60 60 SW 8 12 1832 2040 0 Blue 6
1 AM Fri 60 60 SW 8 12 1832 2040 0 Blue 6
2 AM Fri 60 60 SW 6 12 1832 2040 0 Blue 6
3 AM Fri 60 60 SW 6 12 1832 2040 0 Blue 6
4 AM Fri 60 60 SW 6 12 1832 2040 0 Blue 6
5 AM Fri 60 60 SSW 6 11 1832 2040 0 Blue 6
6 AM Fri 60 60 SSW 6 11 1832 2040 0 Blue 6
7 AM Fri 60 60 SSW 6 11 1832 2040 0 Blue 6
8 AM Fri 59 59 SSW 8 13 1826 2040 0 Blue 5
9 AM Fri 58 58 SSW 8 13 1819 2040 0 Blue 4
10 AM Fri 57 57 SSW 8 13 1811 2040 0 Blue 3
11 AM Fri 56 59 SSW 9 16 1826 2040 0 Blue 5
12 Noon Fri 57 61 SSW 9 16 1838 2040 0 Blue 7
1 PM Fri 58 62 SSW 9 16 1844 2040 0 Blue 8
2 PM Fri 59 63 SSW 9 16 1851 2040 0 Blue 9
3 PM Fri 59 62 SSW 9 16 1844 2040 0 Blue 8
4 PM Fri 59 61 SSW 9 16 1838 2040 0 Blue 7
5 PM Fri 58 60 SW 8 13 1832 2040 0 Blue 6
6 PM Fri 58 59 SW 8 13 1826 2040 0 Blue 5
7 PM Fri 58 58 SW 8 13 1819 2040 0 Blue 4
8 PM Fri 58 58 SW 5 9 1819 2040 0 Blue 4
9 PM Fri 59 59 SW 5 9 1826 2040 0 Blue 5
10 PM Fri 59 59 SW 5 9 1826 2040 0 Blue 5
11 PM Fri 59 59 WSW 3 5 1826 2040 0 Blue 5
12 Midnight Sat 60 60 WSW 3 5 1832 2040 0 Blue 6
1 AM Sat 59 59 WSW 3 5 1826 2040 0 Blue 5
2 AM Sat 59 59 WSW 3 5 1826 2040 0 Blue 5
3 AM Sat 59 59 WSW 3 5 1826 2040 0 Blue 5
4 AM Sat 59 59 WSW 3 5 1826 2040 0 Blue 5
5 AM Sat 59 59 WSW 2 5 1826 2040 0 Blue 5
6 AM Sat 58 58 WSW 2 5 1819 2040 0 Blue 4
7 AM Sat 58 58 WSW 2 5 1819 2040 0 Blue 4
8 AM Sat 58 58 WSW 3 6 1819 2040 0 Blue 4
9 AM Sat 57 57 WSW 3 6 1811 2040 0 Blue 3
10 AM Sat 57 58 WSW 3 6 1819 2040 0 Blue 4
11 AM Sat 57 61 SW 5 10 1838 2040 0 Blue 7
12 Noon Sat 58 63 SW 5 10 1851 2040 0 Blue 9
1 PM Sat 59 64 SW 5 10 1857 2040 0 Blue 10
2 PM Sat 60 65 WSW 6 12 1863 2040 0 Blue 11
3 PM Sat 60 64 WSW 6 12 1857 2040 0 Blue 10
4 PM Sat 59 62 WSW 6 12 1844 2040 0 Blue 8
5 PM Sat 59 62 W 6 12 1844 2040 0 Blue 8
6 PM Sat 58 59 W 6 12 1826 2040 0 Blue 5
7 PM Sat 57 57 W 6 12 1811 2040 0 Blue 3
8 PM Sat 56 56 W 6 11 1677 2040 0 White 2
9 PM Sat 56 56 W 6 11 1677 2040 0 White 2
10 PM Sat 56 56 W 6 11 1677 2040 0 White 2

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]