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:

 250707/1200

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 52 52 WSW 4 8 1321 2040 0 White 0
1 AM Mon 52 52 WSW 4 8 1321 2040 0 White 0
2 AM Mon 52 52 SW 4 8 1321 2040 0 White 0
3 AM Mon 52 52 SW 4 9 1321 2040 0 White 0
4 AM Mon 52 52 SW 5 9 1321 2040 0 White 0
5 AM Mon 51 51 SSW 5 9 1067 2040 0 Blue 0
6 AM Mon 50 50 SSW 5 11 800 2040 0 Blue 0
7 AM Mon 51 51 SSW 6 11 1067 2040 0 Blue 0
8 AM Mon 51 51 SSW 6 12 1067 2040 0 Blue 0
9 AM Mon 52 53 SSW 6 12 1377 2040 0 Blue 1
10 AM Mon 53 55 SSW 8 13 1404 2040 0 Blue 3
11 AM Mon 53 56 SSW 9 16 1417 2040 0 Blue 4
12 Noon Mon 55 59 SW 9 16 1454 2040 0 Blue 7
1 PM Mon 56 61 SW 9 16 1479 2040 0 Blue 9
2 PM Mon 56 61 SW 9 17 1479 2040 0 Blue 9
3 PM Mon 57 61 SW 9 16 1479 2040 0 Blue 9
4 PM Mon 56 59 SW 9 14 1454 2040 0 Blue 7
5 PM Mon 56 58 SW 9 14 1442 2040 0 Blue 6
6 PM Mon 56 57 SW 9 13 1429 2040 0 Blue 5
7 PM Mon 55 55 SW 8 13 1404 2040 0 Blue 3
8 PM Mon 54 54 SW 8 12 1392 2040 0 Blue 2
9 PM Mon 54 54 SW 6 12 1392 2040 0 Blue 2
10 PM Mon 55 55 SW 6 11 1404 2040 0 Blue 3
11 PM Mon 55 55 SW 5 11 1404 2040 0 Blue 3
12 Midnight Tue 55 55 SW 5 11 1404 2040 0 Blue 3
1 AM Tue 55 55 SW 5 11 1404 2040 0 Blue 3
2 AM Tue 54 54 SSW 6 11 1392 2040 0 Blue 2
3 AM Tue 54 54 SSW 6 11 1392 2040 0 Blue 2
4 AM Tue 54 54 SSW 6 11 1392 2040 0 Blue 2
5 AM Tue 54 54 SSW 5 10 1392 2040 0 Blue 2
6 AM Tue 54 54 SSW 5 10 1392 2040 0 Blue 2
7 AM Tue 54 54 SSW 5 10 1392 2040 0 Blue 2
8 AM Tue 54 54 SSW 6 11 1392 2040 0 Blue 2
9 AM Tue 54 55 SSW 6 11 1404 2040 0 Blue 3
10 AM Tue 54 55 SSW 6 11 1404 2040 0 Blue 3
11 AM Tue 55 59 SSW 6 12 1454 2040 0 Blue 7
12 Noon Tue 56 60 SSW 6 12 1466 2040 0 Blue 8
1 PM Tue 58 63 SSW 6 12 1646 2040 0 Blue 11
2 PM Tue 59 66 SW 6 12 1787 2040 0 Blue 14
3 PM Tue 59 65 SW 6 12 1753 2040 0 Blue 13
4 PM Tue 59 63 SW 6 12 1646 2040 0 Blue 11
5 PM Tue 59 62 WSW 6 11 1560 2040 0 Blue 10
6 PM Tue 58 59 WSW 6 11 1454 2040 0 Blue 7
7 PM Tue 58 58 WSW 6 11 1442 2040 0 Blue 6
8 PM Tue 57 57 WSW 5 9 1429 2040 0 Blue 5
9 PM Tue 57 57 WSW 5 9 1429 2040 0 Blue 5
10 PM Tue 57 57 WSW 5 9 1429 2040 0 Blue 5
11 PM Tue 57 57 W 3 6 1429 2040 0 Blue 5
12 Midnight Wed 56 56 W 3 6 1417 2040 0 Blue 4
1 AM Wed 56 56 W 3 6 1417 2040 0 Blue 4
2 AM Wed 55 55 W 3 6 1404 2040 0 Blue 3
3 AM Wed 54 54 W 3 6 1392 2040 0 Blue 2
4 AM Wed 54 54 W 3 6 1392 2040 0 Blue 2
5 AM Wed 53 53 W 3 6 1377 2040 0 Blue 1
6 AM Wed 53 53 W 3 6 1377 2040 0 Blue 1
7 AM Wed 53 53 W 3 6 1377 2040 0 Blue 1
8 AM Wed 54 54 W 4 8 1392 2040 0 Blue 2
9 AM Wed 54 55 W 4 8 1404 2040 0 Blue 3
10 AM Wed 56 58 W 4 8 1442 2040 0 Blue 6
11 AM Wed 57 62 W 5 10 1560 2040 0 Blue 10
12 Noon Wed 59 65 W 5 10 1753 2040 0 Blue 13
1 PM Wed 61 68 W 5 10 1853 2040 0 Blue 16
2 PM Wed 63 71 W 6 12 1977 2040 0 Blue 19
3 PM Wed 64 71 W 6 12 1977 2040 0 Blue 19
4 PM Wed 64 69 W 6 12 1887 2040 0 Blue 17
5 PM Wed 64 67 W 8 12 1820 2040 0 Blue 15
6 PM Wed 62 64 W 8 12 1720 2040 0 Blue 12
7 PM Wed 61 61 W 8 12 1479 2040 0 Blue 9
8 PM Wed 60 60 W 6 11 1466 2040 0 Blue 8
9 PM Wed 59 59 W 6 11 1454 2040 0 Blue 7
10 PM Wed 59 59 W 6 11 1454 2040 0 Blue 7
11 PM Wed 58 58 W 6 11 1442 2040 0 Blue 6
12 Midnight Thu 58 58 W 6 11 1442 2040 0 Blue 6
1 AM Thu 57 57 W 6 11 1429 2040 0 Blue 5
2 AM Thu 56 56 W 5 10 1417 2040 0 Blue 4
3 AM Thu 56 56 W 5 10 1417 2040 0 Blue 4
4 AM Thu 56 56 W 5 10 1417 2040 0 Blue 4
5 AM Thu 56 56 W 5 10 1417 2040 0 Blue 4
6 AM Thu 56 56 W 5 10 1417 2040 0 Blue 4
7 AM Thu 56 56 W 5 10 1417 2040 0 Blue 4
8 AM Thu 57 58 W 4 8 1442 2040 0 Blue 6
9 AM Thu 58 60 W 4 8 1466 2040 0 Blue 8
10 AM Thu 59 63 W 4 8 1646 2040 0 Blue 11
11 AM Thu 61 67 WSW 5 10 1820 2040 0 Blue 15
12 Noon Thu 63 70 WSW 5 10 1920 2040 0 Blue 18
1 PM Thu 65 73 WSW 5 10 2062 2040 0 Blue 21
2 PM Thu 66 73 W 8 13 2062 2040 0 Blue 21
3 PM Thu 67 73 W 8 13 2062 2040 0 Blue 21
4 PM Thu 67 72 W 8 13 2020 2040 0 Blue 20
5 PM Thu 66 69 W 8 12 1887 2040 0 Blue 17
6 PM Thu 65 66 W 8 12 1787 2040 0 Blue 14
7 PM Thu 62 62 W 8 12 1560 2040 0 Blue 10
8 PM Thu 60 60 W 6 11 1466 2040 0 Blue 8
9 PM Thu 59 59 W 6 11 1454 2040 0 Blue 7
10 PM Thu 59 59 W 6 11 1454 2040 0 Blue 7
11 PM Thu 58 58 WSW 5 11 1442 2040 0 Blue 6
12 Midnight Fri 57 57 WSW 5 11 1429 2040 0 Blue 5
1 AM Fri 56 56 WSW 5 11 1417 2040 0 Blue 4
2 AM Fri 55 55 WSW 5 10 1404 2040 0 Blue 3
3 AM Fri 54 54 WSW 5 10 1392 2040 0 Blue 2
4 AM Fri 54 54 WSW 5 10 1392 2040 0 Blue 2
5 AM Fri 54 54 WSW 4 8 1392 2040 0 Blue 2
6 AM Fri 54 54 WSW 4 8 1392 2040 0 Blue 2
7 AM Fri 54 54 WSW 4 8 1392 2040 0 Blue 2
8 AM Fri 54 55 SSW 4 8 1404 2040 0 Blue 3
9 AM Fri 56 58 SSW 4 8 1442 2040 0 Blue 6
10 AM Fri 57 61 SSW 4 8 1479 2040 0 Blue 9
11 AM Fri 59 65 SSW 5 9 1753 2040 0 Blue 13
12 Noon Fri 60 67 SSW 5 9 1820 2040 0 Blue 15
1 PM Fri 62 70 SSW 5 9 1920 2040 0 Blue 18
2 PM Fri 63 71 SW 6 11 1977 2040 0 Blue 19
3 PM Fri 63 70 SW 6 11 1920 2040 0 Blue 18
4 PM Fri 63 68 SW 6 11 1853 2040 0 Blue 16
5 PM Fri 63 66 SW 6 11 1787 2040 0 Blue 14
6 PM Fri 62 63 SW 6 11 1646 2040 0 Blue 11
7 PM Fri 60 60 SW 6 11 1466 2040 0 Blue 8
8 PM Fri 58 58 SW 5 10 1442 2040 0 Blue 6
9 PM Fri 58 58 SW 5 10 1442 2040 0 Blue 6
10 PM Fri 57 57 SW 5 10 1429 2040 0 Blue 5
11 PM Fri 57 57 SW 5 10 1429 2040 0 Blue 5
12 Midnight Sat 56 56 SW 5 10 1417 2040 0 Blue 4
1 AM Sat 56 56 SW 5 10 1417 2040 0 Blue 4
2 AM Sat 55 55 SSW 5 10 1404 2040 0 Blue 3
3 AM Sat 54 54 SSW 5 10 1392 2040 0 Blue 2
4 AM Sat 54 54 SSW 5 10 1392 2040 0 Blue 2
5 AM Sat 54 54 S 5 10 1392 2040 0 Blue 2
6 AM Sat 54 54 S 5 10 1392 2040 0 Blue 2
7 AM Sat 54 54 S 5 10 1392 2040 0 Blue 2
8 AM Sat 54 54 S 6 11 1392 2040 0 Blue 2
9 AM Sat 55 56 S 6 11 1417 2040 0 Blue 4
10 AM Sat 56 58 S 6 11 1442 2040 0 Blue 6
11 AM Sat 58 62 SSW 8 13 1560 2040 0 Blue 10
12 Noon Sat 59 64 SSW 8 13 1720 2040 0 Blue 12
1 PM Sat 60 66 SSW 8 13 1787 2040 0 Blue 14
2 PM Sat 61 68 SW 8 14 1853 2040 0 Blue 16
3 PM Sat 62 68 SW 8 14 1853 2040 0 Blue 16
4 PM Sat 62 66 SW 8 14 1787 2040 0 Blue 14
5 PM Sat 61 64 SW 8 13 1720 2040 0 Blue 12
6 PM Sat 60 61 SW 8 13 1479 2040 0 Blue 9
7 PM Sat 59 59 SW 8 13 1454 2040 0 Blue 7
8 PM Sat 57 57 SW 6 11 1429 2040 0 Blue 5
9 PM Sat 57 57 SW 6 11 1429 2040 0 Blue 5
10 PM Sat 57 57 SW 6 11 1429 2040 0 Blue 5

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]