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

Station:

KOAK

Date/Time:

30 NOV 2022

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 Wed 48 48 WNW 1 2 3693 2444 404 Blue 6
1 AM Wed 48 48 W 1 1 3693 2444 404 Blue 6
2 AM Wed 48 48 WSW 1 2 3693 2444 404 Blue 6
3 AM Wed 47 47 WSW 2 3 3195 2300 260 Blue 5
4 AM Wed 47 47 WSW 2 3 3195 2300 260 Blue 5
5 AM Wed 47 47 WSW 2 4 3195 2300 260 Blue 5
6 AM Wed 46 46 WSW 1 2 2601 2156 116 Blue 4
7 AM Wed 46 46 SSW 1 2 2601 2156 116 Blue 4
8 AM Wed 46 46 S 2 4 2601 2156 116 Blue 4
9 AM Wed 46 46 SSW 3 4 2601 2156 116 Blue 4
10 AM Wed 47 48 SSW 3 4 3693 2444 404 Blue 6
11 AM Wed 50 52 SSW 4 4 4305 3909 1869 Blue 10
12 Noon Wed 51 53 SW 4 5 4416 4033 1993 Blue 11
1 PM Wed 52 53 SW 6 7 4416 4033 1993 Blue 11
2 PM Wed 52 53 SW 7 8 4416 4033 1993 Blue 11
3 PM Wed 52 52 SW 8 10 4305 3909 1869 Blue 10
4 PM Wed 52 52 SW 9 11 4305 3909 1869 Blue 10
5 PM Wed 51 51 SW 9 12 4173 3680 1640 Blue 9
6 PM Wed 51 51 SW 9 13 4173 3680 1640 Blue 9
7 PM Wed 51 51 SSW 8 12 4173 3680 1640 Blue 9
8 PM Wed 50 50 SSW 8 12 4041 3180 1140 Blue 8
9 PM Wed 51 51 SSW 9 13 4173 3680 1640 Blue 9
10 PM Wed 51 51 SSW 12 16 4173 3680 1640 Blue 9
11 PM Wed 50 50 S 14 18 4041 3180 1140 Blue 8
12 Midnight Thu 52 52 S 15 21 4305 3909 1869 Blue 10
1 AM Thu 51 51 S 17 23 4173 3680 1640 Blue 9
2 AM Thu 49 49 S 19 27 3923 2598 558 Blue 7
3 AM Thu 52 52 S 21 29 4305 3909 1869 Blue 10
4 AM Thu 52 52 S 23 32 4305 3909 1869 Blue 10
5 AM Thu 49 49 S 25 34 3923 2598 558 Blue 7
6 AM Thu 52 52 S 27 37 4305 3909 1869 Blue 10
7 AM Thu 52 52 S 30 41 4305 3909 1869 Blue 10
8 AM Thu 49 49 SW 15 20 3923 2598 558 Blue 7
9 AM Thu 47 47 NW 14 18 3195 2300 260 Blue 5
10 AM Thu 45 45 NW 11 15 2446 2040 0 Blue 3
11 AM Thu 49 49 WNW 7 10 3923 2598 558 Blue 7
12 Noon Thu 46 46 W 7 9 2601 2156 116 Blue 4
1 PM Thu 46 46 WNW 5 7 2601 2156 116 Blue 4
2 PM Thu 50 50 W 4 5 4041 3180 1140 Blue 8
3 PM Thu 48 48 W 8 10 3693 2444 404 Blue 6
4 PM Thu 49 49 W 9 12 3923 2598 558 Blue 7
5 PM Thu 51 51 W 10 12 4173 3680 1640 Blue 9
6 PM Thu 49 49 WNW 10 12 3923 2598 558 Blue 7
7 PM Thu 47 47 WNW 8 12 3195 2300 260 Blue 5
8 PM Thu 44 44 WNW 8 13 2301 2040 0 Blue 2
9 PM Thu 46 46 WNW 7 11 2601 2156 116 Blue 4
10 PM Thu 45 45 WNW 6 10 2446 2040 0 Blue 3
11 PM Thu 45 45 W 7 11 2446 2040 0 Blue 3
12 Midnight Fri 45 45 W 8 12 2446 2040 0 Blue 3
1 AM Fri 45 45 WNW 6 10 2446 2040 0 Blue 3
2 AM Fri 45 45 WNW 4 7 2446 2040 0 Blue 3
3 AM Fri 44 44 NW 2 4 2301 2040 0 Blue 2
4 AM Fri 44 44 N 2 4 2301 2040 0 Blue 2
5 AM Fri 44 44 NNE 3 5 2301 2040 0 Blue 2
6 AM Fri 43 43 NE 3 5 2156 2040 0 Blue 1
7 AM Fri 43 43 NE 3 6 2156 2040 0 Blue 1
8 AM Fri 41 41 NE 3 5 1669 2040 0 Blue 0
9 AM Fri 43 43 NE 4 6 2156 2040 0 Blue 1
10 AM Fri 44 45 NE 4 5 2446 2040 0 Blue 3
11 AM Fri 41 42 NE 5 6 1948 2040 0 Blue 0
12 Noon Fri 48 50 NE 5 6 4041 3180 1140 Blue 8
1 PM Fri 48 50 NE 5 6 4041 3180 1140 Blue 8
2 PM Fri 43 44 NE 6 6 2301 2040 0 Blue 2
3 PM Fri 49 49 NE 6 6 3923 2598 558 Blue 7
4 PM Fri 50 50 NNE 5 6 4041 3180 1140 Blue 8
5 PM Fri 44 44 NE 5 6 2301 2040 0 Blue 2
6 PM Fri 49 49 NE 5 8 3923 2598 558 Blue 7
7 PM Fri 48 48 NE 6 10 3693 2444 404 Blue 6
8 PM Fri 40 40 NE 7 11 1387 2040 0 Blue 0
9 PM Fri 47 47 ENE 6 10 3195 2300 260 Blue 5
10 PM Fri 46 46 ENE 6 9 2601 2156 116 Blue 4
11 PM Fri 39 39 NE 6 8 1322 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]