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

Station:

KOAK

Date/Time:

16 JUL 2019

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)
5 AM Tue 59 59 NW 12 1624 2040 0 Blue 1
6 AM Tue 56 56 NW 12 1283 2040 0 Blue 0
7 AM Tue 57 57 NW 12 1427 2040 0 Blue 0
8 AM Tue 58 58 NW 7 1556 2040 0 Blue 0
9 AM Tue 60 62 NW 7 1773 2040 0 Blue 4
10 AM Tue 62 65 NW 7 1845 2040 0 Blue 7
11 AM Tue 66 71 NW 10 2015 2040 0 Blue 13
12 Noon Tue 69 75 NW 10 2353 2076 36 Blue 17
1 PM Tue 70 77 NW 10 2612 2239 199 Blue 19
2 PM Tue 70 77 NW 17 2612 2239 199 Blue 19
3 PM Tue 70 77 NW 17 2612 2239 199 Blue 19
4 PM Tue 71 76 NW 17 2464 2139 99 Blue 18
5 PM Tue 70 73 NW 21 2141 2040 0 Blue 15
6 PM Tue 68 69 NW 21 1942 2040 0 Blue 11
7 PM Tue 65 65 NW 21 1845 2040 0 Blue 7
8 PM Tue 62 62 NW 21 1773 2040 0 Blue 4
9 PM Tue 60 60 NW 21 1693 2040 0 Blue 2
10 PM Tue 60 60 NW 21 1693 2040 0 Blue 2
11 PM Tue 58 58 NW 14 1556 2040 0 Blue 0
12 Midnight Wed 56 56 NW 14 1283 2040 0 Blue 0
1 AM Wed 56 56 NW 14 1283 2040 0 Blue 0
2 AM Wed 56 56 N 5 1283 2040 0 Blue 0
3 AM Wed 57 57 N 5 1427 2040 0 Blue 0
4 AM Wed 55 55 N 5 1140 2040 0 Blue 0
5 AM Wed 56 56 N 1 1283 2040 0 Blue 0
6 AM Wed 54 54 N 1 1033 2040 0 Blue 0
7 AM Wed 54 54 N 1 1033 2040 0 Blue 0
8 AM Wed 55 55 E 3 1140 2040 0 Blue 0
9 AM Wed 58 59 E 3 1624 2040 0 Blue 1
10 AM Wed 59 62 E 3 1773 2040 0 Blue 4
11 AM Wed 62 67 W 5 1894 2040 0 Blue 9
12 Noon Wed 64 71 W 5 2015 2040 0 Blue 13
1 PM Wed 66 73 W 5 2141 2040 0 Blue 15
2 PM Wed 67 74 W 9 2243 2040 0 Blue 16
3 PM Wed 69 75 W 9 2353 2076 36 Blue 17
4 PM Wed 70 75 W 9 2353 2076 36 Blue 17
5 PM Wed 70 73 NW 9 2141 2040 0 Blue 15
6 PM Wed 68 69 NW 9 1942 2040 0 Blue 11
7 PM Wed 66 66 NW 9 1869 2040 0 Blue 8
8 PM Wed 63 63 NW 7 1797 2040 0 Blue 5
9 PM Wed 61 61 NW 7 1749 2040 0 Blue 3
10 PM Wed 60 60 NW 7 1693 2040 0 Blue 2
11 PM Wed 59 59 NW 3 1624 2040 0 Blue 1
12 Midnight Thu 58 58 NW 3 1556 2040 0 Blue 0
1 AM Thu 57 57 NW 3 1427 2040 0 Blue 0
2 AM Thu 56 56 NW 2 1283 2040 0 Blue 0
3 AM Thu 56 56 NW 2 1283 2040 0 Blue 0
4 AM Thu 56 56 NW 2 1283 2040 0 Blue 0
5 AM Thu 55 55 W 2 1140 2040 0 Blue 0
6 AM Thu 54 54 W 2 1033 2040 0 Blue 0
7 AM Thu 54 54 W 2 1033 2040 0 Blue 0
8 AM Thu 54 54 SW 2 1033 2040 0 Blue 0
9 AM Thu 56 56 SW 2 1283 2040 0 Blue 0
10 AM Thu 58 59 SW 2 1624 2040 0 Blue 1
11 AM Thu 60 65 SW 5 1845 2040 0 Blue 7
12 Noon Thu 62 68 SW 5 1918 2040 0 Blue 10
1 PM Thu 64 71 SW 5 2015 2040 0 Blue 13
2 PM Thu 65 72 SW 6 2078 2040 0 Blue 14
3 PM Thu 66 72 SW 6 2078 2040 0 Blue 14
4 PM Thu 66 70 SW 6 1966 2040 0 Blue 12
5 PM Thu 66 69 W 7 1942 2040 0 Blue 11
6 PM Thu 64 65 W 7 1845 2040 0 Blue 7
7 PM Thu 63 63 W 7 1797 2040 0 Blue 5
8 PM Thu 61 61 W 7 1749 2040 0 Blue 3
9 PM Thu 60 60 W 7 1693 2040 0 Blue 2
10 PM Thu 59 59 W 7 1624 2040 0 Blue 1
11 PM Thu 59 59 SW 10 1624 2040 0 Blue 1
12 Midnight Fri 58 58 SW 10 1556 2040 0 Blue 0
1 AM Fri 58 58 SW 10 1556 2040 0 Blue 0
2 AM Fri 58 58 SW 10 1556 2040 0 Blue 0
3 AM Fri 58 58 SW 10 1556 2040 0 Blue 0
4 AM Fri 57 57 SW 10 1427 2040 0 Blue 0
5 AM Fri 57 57 S 9 1427 2040 0 Blue 0
6 AM Fri 56 56 S 9 1283 2040 0 Blue 0
7 AM Fri 55 55 S 9 1140 2040 0 Blue 0
8 AM Fri 54 54 S 9 1033 2040 0 Blue 0
9 AM Fri 55 55 S 9 1140 2040 0 Blue 0
10 AM Fri 56 57 S 9 1427 2040 0 Blue 0
11 AM Fri 58 62 S 10 1773 2040 0 Blue 4
12 Noon Fri 60 65 S 10 1845 2040 0 Blue 7
1 PM Fri 62 68 S 10 1918 2040 0 Blue 10
2 PM Fri 63 69 SW 10 1942 2040 0 Blue 11
3 PM Fri 64 69 SW 10 1942 2040 0 Blue 11
4 PM Fri 64 68 SW 10 1918 2040 0 Blue 10
5 PM Fri 64 66 SW 10 1869 2040 0 Blue 8
6 PM Fri 62 63 SW 10 1797 2040 0 Blue 5
7 PM Fri 61 61 SW 10 1749 2040 0 Blue 3
8 PM Fri 59 59 SW 9 1624 2040 0 Blue 1
9 PM Fri 58 58 SW 9 1556 2040 0 Blue 0
10 PM Fri 57 57 SW 9 1427 2040 0 Blue 0
11 PM Fri 56 56 SW 8 1283 2040 0 Blue 0
12 Midnight Sat 56 56 SW 8 1283 2040 0 Blue 0
1 AM Sat 56 56 SW 8 1283 2040 0 Blue 0
2 AM Sat 56 56 SW 8 1283 2040 0 Blue 0
3 AM Sat 56 56 SW 8 1283 2040 0 Blue 0
4 AM Sat 56 56 SW 8 1283 2040 0 Blue 0
5 AM Sat 55 55 S 9 1140 2040 0 Blue 0
6 AM Sat 54 54 S 9 1033 2040 0 Blue 0
7 AM Sat 54 54 S 9 1033 2040 0 Blue 0
8 AM Sat 54 54 S 9 1033 2040 0 Blue 0
9 AM Sat 55 55 S 9 1140 2040 0 Blue 0
10 AM Sat 57 58 S 9 1556 2040 0 Blue 0
11 AM Sat 59 64 S 9 1821 2040 0 Blue 6
12 Noon Sat 61 68 S 9 1918 2040 0 Blue 10
1 PM Sat 62 69 S 9 1942 2040 0 Blue 11
2 PM Sat 64 71 SW 9 2015 2040 0 Blue 13
3 PM Sat 65 71 SW 9 2015 2040 0 Blue 13
4 PM Sat 66 71 SW 9 2015 2040 0 Blue 13
5 PM Sat 65 68 SW 9 1918 2040 0 Blue 10
6 PM Sat 64 65 SW 9 1845 2040 0 Blue 7
7 PM Sat 61 61 SW 9 1749 2040 0 Blue 3
8 PM Sat 59 59 SW 8 1624 2040 0 Blue 1
9 PM Sat 58 58 SW 8 1556 2040 0 Blue 0
10 PM Sat 57 57 SW 8 1427 2040 0 Blue 0
11 PM Sat 57 57 W 7 1427 2040 0 Blue 0
12 Midnight Sun 56 56 W 7 1283 2040 0 Blue 0
1 AM Sun 56 56 W 7 1283 2040 0 Blue 0
2 AM Sun 55 55 W 8 1140 2040 0 Blue 0
3 AM Sun 55 55 W 8 1140 2040 0 Blue 0
4 AM Sun 55 55 W 8 1140 2040 0 Blue 0
5 AM Sun 55 55 W 8 1140 2040 0 Blue 0
6 AM Sun 54 54 W 8 1033 2040 0 Blue 0
7 AM Sun 54 54 W 8 1033 2040 0 Blue 0
8 AM Sun 54 54 S 8 1033 2040 0 Blue 0
9 AM Sun 55 55 S 8 1140 2040 0 Blue 0
10 AM Sun 56 57 S 8 1427 2040 0 Blue 0
11 AM Sun 59 64 S 9 1821 2040 0 Blue 6
12 Noon Sun 61 68 S 9 1918 2040 0 Blue 10
1 PM Sun 63 70 S 9 1966 2040 0 Blue 12
2 PM Sun 65 72 W 8 2078 2040 0 Blue 14
3 PM Sun 66 72 W 8 2078 2040 0 Blue 14
4 PM Sun 66 71 W 8 2015 2040 0 Blue 13
5 PM Sun 66 69 W 9 1942 2040 0 Blue 11
6 PM Sun 64 65 W 9 1845 2040 0 Blue 7
7 PM Sun 62 62 W 9 1773 2040 0 Blue 4
8 PM Sun 60 60 W 9 1693 2040 0 Blue 2
9 PM Sun 58 58 W 9 1556 2040 0 Blue 0
10 PM Sun 57 57 W 9 1427 2040 0 Blue 0
11 PM Sun 56 56 W 7 1283 2040 0 Blue 0
12 Midnight Mon 56 56 W 7 1283 2040 0 Blue 0
1 AM Mon 55 55 W 7 1140 2040 0 Blue 0
2 AM Mon 55 55 W 8 1140 2040 0 Blue 0
3 AM Mon 55 55 W 8 1140 2040 0 Blue 0
4 AM Mon 55 55 W 8 1140 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 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