Detailed Predictions for: Mt Tamalpais
Launch Altitude (f): 2040
LZ Altitude (f): 0
Sounding

Station:

KOAK

Date/Time:

N/A

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
4 AM Thu 50 50 SW 22 N/A N/A N/A N/A N/A
5 AM Thu 50 50 SW 22 N/A N/A N/A N/A N/A
6 AM Thu 51 51 SW 22 N/A N/A N/A N/A N/A
7 AM Thu 50 50 SW 22 N/A N/A N/A N/A N/A
8 AM Thu 50 50 SW 22 N/A N/A N/A N/A N/A
9 AM Thu 50 50 SW 22 N/A N/A N/A N/A N/A
10 AM Thu 51 51 SW 21 N/A N/A N/A N/A N/A
11 AM Thu 52 52 SW 21 N/A N/A N/A N/A N/A
12 Noon Thu 53 53 SW 21 N/A N/A N/A N/A N/A
1 PM Thu 54 54 SW 20 N/A N/A N/A N/A N/A
2 PM Thu 54 54 SW 20 N/A N/A N/A N/A N/A
3 PM Thu 53 53 SW 20 N/A N/A N/A N/A N/A
4 PM Thu 52 52 SW 17 N/A N/A N/A N/A N/A
5 PM Thu 52 52 SW 17 N/A N/A N/A N/A N/A
6 PM Thu 51 51 SW 17 N/A N/A N/A N/A N/A
7 PM Thu 51 51 W 17 N/A N/A N/A N/A N/A
8 PM Thu 51 51 W 17 N/A N/A N/A N/A N/A
9 PM Thu 50 50 W 17 N/A N/A N/A N/A N/A
10 PM Thu 50 50 SW 12 N/A N/A N/A N/A N/A
11 PM Thu 49 49 SW 12 N/A N/A N/A N/A N/A
12 Midnight Fri 49 49 SW 12 N/A N/A N/A N/A N/A
1 AM Fri 49 49 SW 7 N/A N/A N/A N/A N/A
2 AM Fri 48 48 SW 7 N/A N/A N/A N/A N/A
3 AM Fri 48 48 SW 7 N/A N/A N/A N/A N/A
4 AM Fri 48 48 S 9 N/A N/A N/A N/A N/A
5 AM Fri 48 48 S 9 N/A N/A N/A N/A N/A
6 AM Fri 48 48 S 9 N/A N/A N/A N/A N/A
7 AM Fri 47 47 S 9 N/A N/A N/A N/A N/A
8 AM Fri 47 47 S 9 N/A N/A N/A N/A N/A
9 AM Fri 48 48 S 9 N/A N/A N/A N/A N/A
10 AM Fri 50 50 S 8 N/A N/A N/A N/A N/A
11 AM Fri 52 52 S 8 N/A N/A N/A N/A N/A
12 Noon Fri 53 54 S 8 N/A N/A N/A N/A N/A
1 PM Fri 54 55 S 9 N/A N/A N/A N/A N/A
2 PM Fri 54 54 S 9 N/A N/A N/A N/A N/A
3 PM Fri 54 54 S 9 N/A N/A N/A N/A N/A
4 PM Fri 53 53 S 8 N/A N/A N/A N/A N/A
5 PM Fri 52 52 S 8 N/A N/A N/A N/A N/A
6 PM Fri 52 52 S 8 N/A N/A N/A N/A N/A
7 PM Fri 52 52 S 8 N/A N/A N/A N/A N/A
8 PM Fri 52 52 S 8 N/A N/A N/A N/A N/A
9 PM Fri 51 51 S 8 N/A N/A N/A N/A N/A
10 PM Fri 51 51 S 5 N/A N/A N/A N/A N/A
11 PM Fri 50 50 S 5 N/A N/A N/A N/A N/A
12 Midnight Sat 50 50 S 5 N/A N/A N/A N/A N/A
1 AM Sat 50 50 S 5 N/A N/A N/A N/A N/A
2 AM Sat 50 50 S 5 N/A N/A N/A N/A N/A
3 AM Sat 49 49 S 5 N/A N/A N/A N/A N/A
4 AM Sat 49 49 SW 5 N/A N/A N/A N/A N/A
5 AM Sat 49 49 SW 5 N/A N/A N/A N/A N/A
6 AM Sat 49 49 SW 5 N/A N/A N/A N/A N/A
7 AM Sat 49 49 SW 5 N/A N/A N/A N/A N/A
8 AM Sat 49 49 SW 5 N/A N/A N/A N/A N/A
9 AM Sat 50 50 SW 5 N/A N/A N/A N/A N/A
10 AM Sat 51 51 W 7 N/A N/A N/A N/A N/A
11 AM Sat 54 54 W 7 N/A N/A N/A N/A N/A
12 Noon Sat 55 55 W 7 N/A N/A N/A N/A N/A
1 PM Sat 56 56 W 7 N/A N/A N/A N/A N/A
2 PM Sat 56 56 W 7 N/A N/A N/A N/A N/A
3 PM Sat 56 56 W 7 N/A N/A N/A N/A N/A
4 PM Sat 55 55 W 6 N/A N/A N/A N/A N/A
5 PM Sat 54 54 W 6 N/A N/A N/A N/A N/A
6 PM Sat 54 54 W 6 N/A N/A N/A N/A N/A
7 PM Sat 53 53 W 6 N/A N/A N/A N/A N/A
8 PM Sat 53 53 W 6 N/A N/A N/A N/A N/A
9 PM Sat 53 53 W 6 N/A N/A N/A N/A N/A
10 PM Sat 52 52 SW 8 N/A N/A N/A N/A N/A
11 PM Sat 52 52 SW 8 N/A N/A N/A N/A N/A
12 Midnight Sun 51 51 SW 8 N/A N/A N/A N/A N/A
1 AM Sun 51 51 SW 8 N/A N/A N/A N/A N/A
2 AM Sun 51 51 SW 8 N/A N/A N/A N/A N/A
3 AM Sun 50 50 SW 8 N/A N/A N/A N/A N/A
4 AM Sun 50 50 S 9 N/A N/A N/A N/A N/A
5 AM Sun 50 50 S 9 N/A N/A N/A N/A N/A
6 AM Sun 50 50 S 9 N/A N/A N/A N/A N/A
7 AM Sun 50 50 S 9 N/A N/A N/A N/A N/A
8 AM Sun 50 50 S 9 N/A N/A N/A N/A N/A
9 AM Sun 50 50 S 9 N/A N/A N/A N/A N/A
10 AM Sun 51 51 W 18 N/A N/A N/A N/A N/A
11 AM Sun 53 53 W 18 N/A N/A N/A N/A N/A
12 Noon Sun 54 54 W 18 N/A N/A N/A N/A N/A
1 PM Sun 54 54 W 18 N/A N/A N/A N/A N/A
2 PM Sun 54 54 W 18 N/A N/A N/A N/A N/A
3 PM Sun 54 54 W 18 N/A N/A N/A N/A N/A
4 PM Sun 52 52 W 20 N/A N/A N/A N/A N/A
5 PM Sun 51 51 W 20 N/A N/A N/A N/A N/A
6 PM Sun 50 50 W 20 N/A N/A N/A N/A N/A
7 PM Sun 50 50 W 20 N/A N/A N/A N/A N/A
8 PM Sun 50 50 W 20 N/A N/A N/A N/A N/A
9 PM Sun 49 49 W 20 N/A N/A N/A N/A N/A
10 PM Sun 48 48 NW 16 N/A N/A N/A N/A N/A
11 PM Sun 47 47 NW 16 N/A N/A N/A N/A N/A
12 Midnight Mon 46 46 NW 16 N/A N/A N/A N/A N/A
1 AM Mon 46 46 NW 16 N/A N/A N/A N/A N/A
2 AM Mon 45 45 NW 16 N/A N/A N/A N/A N/A
3 AM Mon 45 45 NW 16 N/A N/A N/A N/A N/A
4 AM Mon 44 44 NW 15 N/A N/A N/A N/A N/A
5 AM Mon 45 45 NW 15 N/A N/A N/A N/A N/A
6 AM Mon 44 44 NW 15 N/A N/A N/A N/A N/A
7 AM Mon 44 44 NW 15 N/A N/A N/A N/A N/A
8 AM Mon 43 43 NW 15 N/A N/A N/A N/A N/A
9 AM Mon 45 45 NW 15 N/A N/A N/A N/A N/A
10 AM Mon 47 48 N 14 N/A N/A N/A N/A N/A
11 AM Mon 51 52 N 14 N/A N/A N/A N/A N/A
12 Noon Mon 52 53 N 14 N/A N/A N/A N/A N/A
1 PM Mon 54 55 N 14 N/A N/A N/A N/A N/A
2 PM Mon 54 55 N 14 N/A N/A N/A N/A N/A
3 PM Mon 54 54 N 14 N/A N/A N/A N/A N/A
4 PM Mon 52 52 NW 15 N/A N/A N/A N/A N/A
5 PM Mon 51 51 NW 15 N/A N/A N/A N/A N/A
6 PM Mon 50 50 NW 15 N/A N/A N/A N/A N/A
7 PM Mon 50 50 NW 15 N/A N/A N/A N/A N/A
8 PM Mon 50 50 NW 15 N/A N/A N/A N/A N/A
9 PM Mon 49 49 NW 15 N/A N/A N/A N/A N/A
10 PM Mon 48 48 N 14 N/A N/A N/A N/A N/A
11 PM Mon 47 47 N 14 N/A N/A N/A N/A N/A
12 Midnight Tue 46 46 N 14 N/A N/A N/A N/A N/A
1 AM Tue 46 46 N 14 N/A N/A N/A N/A N/A
2 AM Tue 45 45 N 14 N/A N/A N/A N/A N/A
3 AM Tue 45 45 N 14 N/A N/A N/A N/A N/A
4 AM Tue 45 45 N 13 N/A N/A N/A N/A N/A
5 AM Tue 45 45 N 13 N/A N/A N/A N/A N/A
6 AM Tue 45 45 N 13 N/A N/A N/A N/A N/A
7 AM Tue 44 44 N 13 N/A N/A N/A N/A N/A
8 AM Tue 44 44 N 13 N/A N/A N/A N/A N/A
9 AM Tue 45 45 N 13 N/A N/A N/A N/A N/A
10 AM Tue 48 49 N 12 N/A N/A N/A N/A N/A
11 AM Tue 52 53 N 12 N/A N/A N/A N/A N/A
12 Noon Tue 54 56 N 12 N/A N/A N/A N/A N/A
1 PM Tue 55 57 N 12 N/A N/A N/A N/A N/A
2 PM Tue 55 56 N 12 N/A N/A N/A N/A N/A
3 PM Tue 55 55 N 12 N/A N/A N/A N/A N/A
4 PM Tue 54 54 N 9 N/A N/A N/A N/A N/A
5 PM Tue 52 52 N 9 N/A N/A N/A N/A N/A
6 PM Tue 52 52 N 9 N/A N/A N/A N/A N/A
7 PM Tue 51 51 N 9 N/A N/A N/A N/A N/A
8 PM Tue 51 51 N 9 N/A N/A N/A N/A N/A
9 PM Tue 51 51 N 9 N/A N/A N/A N/A N/A
10 PM Tue 50 50 N 7 N/A N/A N/A N/A N/A
11 PM Tue 48 48 N 7 N/A N/A N/A N/A N/A
12 Midnight Wed 48 48 N 7 N/A N/A N/A N/A N/A
1 AM Wed 48 48 N 7 N/A N/A N/A N/A N/A
2 AM Wed 47 47 N 7 N/A N/A N/A N/A N/A
3 AM Wed 46 46 N 7 N/A N/A N/A N/A N/A

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 website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service 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 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 ac_soaring@yahoo.com