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

Station:

 KOAK

Date/Time:

 11 DEC 2023

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 50 50 NNW 6 8 673 2040 0 Blue 0
1 AM Mon 50 50 NNW 8 8 673 2040 0 Blue 0
2 AM Mon 49 49 NNW 8 8 673 2040 0 Blue 0
3 AM Mon 49 49 NNW 8 10 673 2040 0 Blue 0
4 AM Mon 47 47 NNW 8 10 673 2040 0 Blue 0
5 AM Mon 49 49 NNW 8 10 673 2040 0 Blue 0
6 AM Mon 48 48 NNW 9 10 673 2040 0 Blue 0
7 AM Mon 48 48 NNW 8 10 673 2040 0 Blue 0
8 AM Mon 48 48 NNW 8 11 673 2040 0 Blue 0
9 AM Mon 50 50 NNW 8 11 673 2040 0 Blue 0
10 AM Mon 52 53 NNW 8 12 1245 2040 0 Blue 0
11 AM Mon 53 54 NW 9 13 1510 2040 0 Blue 0
12 Noon Mon 54 55 NW 9 13 1982 2040 0 Blue 1
1 PM Mon 55 56 NW 9 13 2097 2040 0 Blue 2
2 PM Mon 55 56 NW 9 12 2097 2040 0 Blue 2
3 PM Mon 55 55 NW 10 12 1982 2040 0 Blue 1
4 PM Mon 54 54 NW 10 12 1510 2040 0 Blue 0
5 PM Mon 53 53 NW 10 12 1245 2040 0 Blue 0
6 PM Mon 53 53 NW 10 11 1245 2040 0 Blue 0
7 PM Mon 53 53 NW 10 11 1245 2040 0 Blue 0
8 PM Mon 54 54 NW 10 11 1510 2040 0 Blue 0
9 PM Mon 54 54 NNW 9 10 1510 2040 0 Blue 0
10 PM Mon 53 53 NW 9 10 1245 2040 0 Blue 0
11 PM Mon 53 53 NNW 9 9 1245 2040 0 Blue 0
12 Midnight Tue 52 52 NNW 9 9 1047 2040 0 Blue 0
1 AM Tue 52 52 NNW 8 9 1047 2040 0 Blue 0
2 AM Tue 53 53 NNW 6 8 1245 2040 0 Blue 0
3 AM Tue 52 52 NNW 6 8 1047 2040 0 Blue 0
4 AM Tue 52 52 N 6 6 1047 2040 0 Blue 0
5 AM Tue 51 51 N 6 6 848 2040 0 Blue 0
6 AM Tue 50 50 N 5 6 673 2040 0 Blue 0
7 AM Tue 50 50 N 5 6 673 2040 0 Blue 0
8 AM Tue 48 48 N 5 6 673 2040 0 Blue 0
9 AM Tue 50 50 N 5 6 673 2040 0 Blue 0
10 AM Tue 52 52 N 5 6 1047 2040 0 Blue 0
11 AM Tue 53 53 N 5 6 1245 2040 0 Blue 0
12 Noon Tue 53 54 N 5 6 1510 2040 0 Blue 0
1 PM Tue 54 55 WNW 5 9 1982 2040 0 Blue 1
2 PM Tue 54 55 WNW 5 9 1982 2040 0 Blue 1
3 PM Tue 54 54 WNW 5 9 1510 2040 0 Blue 0
4 PM Tue 54 54 WNW 6 10 1510 2040 0 Blue 0
5 PM Tue 53 53 WNW 6 10 1245 2040 0 Blue 0
6 PM Tue 52 52 WNW 6 10 1047 2040 0 Blue 0
7 PM Tue 51 51 NW 6 8 848 2040 0 Blue 0
8 PM Tue 50 50 NW 6 8 673 2040 0 Blue 0
9 PM Tue 51 51 NW 6 8 848 2040 0 Blue 0
10 PM Tue 51 51 NNW 5 5 848 2040 0 Blue 0
11 PM Tue 51 51 NNW 5 5 848 2040 0 Blue 0
12 Midnight Wed 52 52 NNW 5 5 1047 2040 0 Blue 0
1 AM Wed 52 52 NNE 5 6 1047 2040 0 Blue 0
2 AM Wed 51 51 NNE 5 6 848 2040 0 Blue 0
3 AM Wed 50 50 NNE 5 6 673 2040 0 Blue 0
4 AM Wed 50 50 NE 6 10 673 2040 0 Blue 0
5 AM Wed 49 49 NE 6 10 673 2040 0 Blue 0
6 AM Wed 49 49 NE 6 10 673 2040 0 Blue 0
7 AM Wed 48 48 NE 9 11 673 2040 0 Blue 0
8 AM Wed 48 48 NE 9 11 673 2040 0 Blue 0
9 AM Wed 48 48 NE 9 11 673 2040 0 Blue 0
10 AM Wed 48 49 NE 10 13 673 2040 0 Blue 0
11 AM Wed 50 51 NE 10 13 848 2040 0 Blue 0
12 Noon Wed 52 53 NE 10 13 1245 2040 0 Blue 0
1 PM Wed 53 54 NNE 9 12 1510 2040 0 Blue 0
2 PM Wed 54 55 NNE 9 12 1982 2040 0 Blue 1
3 PM Wed 54 54 NNE 9 12 1510 2040 0 Blue 0
4 PM Wed 53 53 N 6 10 1245 2040 0 Blue 0
5 PM Wed 53 53 N 6 10 1245 2040 0 Blue 0
6 PM Wed 52 52 N 6 10 1047 2040 0 Blue 0
7 PM Wed 51 51 N 6 9 848 2040 0 Blue 0
8 PM Wed 51 51 N 6 9 848 2040 0 Blue 0
9 PM Wed 51 51 N 6 9 848 2040 0 Blue 0
10 PM Wed 51 51 NNE 6 9 848 2040 0 Blue 0
11 PM Wed 51 51 NNE 6 9 848 2040 0 Blue 0
12 Midnight Thu 51 51 NNE 6 9 848 2040 0 Blue 0
1 AM Thu 50 50 NE 8 10 673 2040 0 Blue 0
2 AM Thu 50 50 NE 8 10 673 2040 0 Blue 0
3 AM Thu 50 50 NE 8 10 673 2040 0 Blue 0
4 AM Thu 50 50 NE 9 11 673 2040 0 Blue 0
5 AM Thu 49 49 NE 9 11 673 2040 0 Blue 0
6 AM Thu 48 48 NE 9 11 673 2040 0 Blue 0
7 AM Thu 48 48 ENE 10 12 673 2040 0 Blue 0
8 AM Thu 48 48 ENE 10 12 673 2040 0 Blue 0
9 AM Thu 48 48 ENE 10 12 673 2040 0 Blue 0
10 AM Thu 49 49 ENE 10 13 673 2040 0 Blue 0
11 AM Thu 50 50 ENE 10 13 673 2040 0 Blue 0
12 Noon Thu 51 52 ENE 10 13 1047 2040 0 Blue 0
1 PM Thu 52 52 ENE 10 13 1047 2040 0 Blue 0
2 PM Thu 53 53 ENE 10 13 1245 2040 0 Blue 0
3 PM Thu 53 53 ENE 10 13 1245 2040 0 Blue 0
4 PM Thu 52 52 ENE 9 13 1047 2040 0 Blue 0
5 PM Thu 52 52 ENE 9 13 1047 2040 0 Blue 0
6 PM Thu 51 51 ENE 9 13 848 2040 0 Blue 0
7 PM Thu 51 51 ENE 10 11 848 2040 0 Blue 0
8 PM Thu 51 51 ENE 10 11 848 2040 0 Blue 0
9 PM Thu 51 51 ENE 10 11 848 2040 0 Blue 0
10 PM Thu 52 52 ENE 9 11 1047 2040 0 Blue 0
11 PM Thu 51 51 ENE 9 11 848 2040 0 Blue 0
12 Midnight Fri 51 51 ENE 9 11 848 2040 0 Blue 0
1 AM Fri 51 51 ENE 10 11 848 2040 0 Blue 0
2 AM Fri 50 50 ENE 10 11 673 2040 0 Blue 0
3 AM Fri 50 50 ENE 10 11 673 2040 0 Blue 0
4 AM Fri 50 50 ENE 11 12 673 2040 0 Blue 0
5 AM Fri 50 50 ENE 11 12 673 2040 0 Blue 0
6 AM Fri 50 50 ENE 11 12 673 2040 0 Blue 0
7 AM Fri 49 49 ENE 11 14 673 2040 0 Blue 0
8 AM Fri 49 49 ENE 11 14 673 2040 0 Blue 0
9 AM Fri 49 49 ENE 11 14 673 2040 0 Blue 0
10 AM Fri 50 50 ENE 12 16 673 2040 0 Blue 0
11 AM Fri 51 51 ENE 12 16 848 2040 0 Blue 0
12 Noon Fri 52 52 ENE 12 16 1047 2040 0 Blue 0
1 PM Fri 53 53 ENE 12 16 1245 2040 0 Blue 0
2 PM Fri 54 54 ENE 12 16 1510 2040 0 Blue 0
3 PM Fri 54 54 ENE 12 16 1510 2040 0 Blue 0
4 PM Fri 53 53 ENE 11 13 1245 2040 0 Blue 0
5 PM Fri 53 53 ENE 11 13 1245 2040 0 Blue 0
6 PM Fri 52 52 ENE 11 13 1047 2040 0 Blue 0
7 PM Fri 52 52 ENE 11 12 1047 2040 0 Blue 0
8 PM Fri 52 52 ENE 11 12 1047 2040 0 Blue 0
9 PM Fri 52 52 ENE 11 12 1047 2040 0 Blue 0
10 PM Fri 52 52 ENE 10 12 1047 2040 0 Blue 0
11 PM Fri 52 52 ENE 10 12 1047 2040 0 Blue 0
12 Midnight Sat 52 52 ENE 10 12 1047 2040 0 Blue 0
1 AM Sat 52 52 ENE 11 12 1047 2040 0 Blue 0
2 AM Sat 52 52 ENE 11 12 1047 2040 0 Blue 0
3 AM Sat 51 51 ENE 11 12 848 2040 0 Blue 0
4 AM Sat 50 50 ENE 11 13 673 2040 0 Blue 0
5 AM Sat 50 50 ENE 11 13 673 2040 0 Blue 0
6 AM Sat 50 50 ENE 11 13 673 2040 0 Blue 0
7 AM Sat 49 49 ENE 11 14 673 2040 0 Blue 0
8 AM Sat 49 49 ENE 11 14 673 2040 0 Blue 0
9 AM Sat 50 50 ENE 11 14 673 2040 0 Blue 0
10 AM Sat 51 52 ENE 12 14 1047 2040 0 Blue 0
11 AM Sat 52 53 ENE 12 14 1245 2040 0 Blue 0
12 Noon Sat 53 54 ENE 12 14 1510 2040 0 Blue 0
1 PM Sat 54 55 ENE 12 14 1982 2040 0 Blue 1
2 PM Sat 55 56 ENE 12 14 2097 2040 0 Blue 2
3 PM Sat 55 55 ENE 12 14 1982 2040 0 Blue 1
4 PM Sat 55 55 ENE 11 13 1982 2040 0 Blue 1
5 PM Sat 54 54 ENE 11 13 1510 2040 0 Blue 0
6 PM Sat 54 54 ENE 11 13 1510 2040 0 Blue 0
7 PM Sat 53 53 ENE 10 12 1245 2040 0 Blue 0
8 PM Sat 53 53 ENE 10 12 1245 2040 0 Blue 0
9 PM Sat 53 53 ENE 10 12 1245 2040 0 Blue 0
10 PM Sat 53 53 ENE 10 12 1245 2040 0 Blue 0

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]